add rust lang to repo by add assets/mini-redis
This commit is contained in:
sunface
parent
d0c4a4669a
commit
58cb728626
|
|
@ -0,0 +1,24 @@
|
|||
name: CI
|
||||
|
||||
on:
|
||||
push:
|
||||
branches: [ master ]
|
||||
pull_request:
|
||||
branches: [ master ]
|
||||
|
||||
jobs:
|
||||
build:
|
||||
|
||||
runs-on: ubuntu-latest
|
||||
|
||||
steps:
|
||||
- uses: actions/checkout@v2
|
||||
- name: Build
|
||||
run: cargo build --verbose
|
||||
- name: Run tests
|
||||
run: cargo test --verbose
|
||||
- name: rustfmt
|
||||
uses: actions-rs/cargo@v1
|
||||
with:
|
||||
command: fmt
|
||||
args: --all -- --check
|
||||
|
|
@ -0,0 +1,2 @@
|
|||
/target
|
||||
**/*.rs.bk
|
||||
|
|
@ -0,0 +1,695 @@
|
|||
# This file is automatically @generated by Cargo.
|
||||
# It is not intended for manual editing.
|
||||
version = 3
|
||||
|
||||
[[package]]
|
||||
name = "ansi_term"
|
||||
version = "0.11.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
|
||||
dependencies = [
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "ansi_term"
|
||||
version = "0.12.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2"
|
||||
dependencies = [
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "async-stream"
|
||||
version = "0.3.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "171374e7e3b2504e0e5236e3b59260560f9fe94bfe9ac39ba5e4e929c5590625"
|
||||
dependencies = [
|
||||
"async-stream-impl",
|
||||
"futures-core",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "async-stream-impl"
|
||||
version = "0.3.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "648ed8c8d2ce5409ccd57453d9d1b214b342a0d69376a6feda1fd6cae3299308"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"syn",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "atoi"
|
||||
version = "0.3.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "5c897df197d57c25b37df9d8fa2f93ddbfeee9ebd2264350ac79c8ec4b795885"
|
||||
dependencies = [
|
||||
"num-traits",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "atty"
|
||||
version = "0.2.14"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
|
||||
dependencies = [
|
||||
"hermit-abi",
|
||||
"libc",
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "autocfg"
|
||||
version = "1.0.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
|
||||
|
||||
[[package]]
|
||||
name = "bitflags"
|
||||
version = "1.2.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
|
||||
|
||||
[[package]]
|
||||
name = "bytes"
|
||||
version = "1.0.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "b700ce4376041dcd0a327fd0097c41095743c4c8af8887265942faf1100bd040"
|
||||
|
||||
[[package]]
|
||||
name = "cfg-if"
|
||||
version = "1.0.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
|
||||
|
||||
[[package]]
|
||||
name = "chrono"
|
||||
version = "0.4.19"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
|
||||
dependencies = [
|
||||
"libc",
|
||||
"num-integer",
|
||||
"num-traits",
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "clap"
|
||||
version = "2.33.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "37e58ac78573c40708d45522f0d80fa2f01cc4f9b4e2bf749807255454312002"
|
||||
dependencies = [
|
||||
"ansi_term 0.11.0",
|
||||
"atty",
|
||||
"bitflags",
|
||||
"strsim",
|
||||
"textwrap",
|
||||
"unicode-width",
|
||||
"vec_map",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "futures-core"
|
||||
version = "0.3.15"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "0402f765d8a89a26043b889b26ce3c4679d268fa6bb22cd7c6aad98340e179d1"
|
||||
|
||||
[[package]]
|
||||
name = "heck"
|
||||
version = "0.3.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
|
||||
dependencies = [
|
||||
"unicode-segmentation",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "hermit-abi"
|
||||
version = "0.1.19"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
|
||||
dependencies = [
|
||||
"libc",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "instant"
|
||||
version = "0.1.10"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "bee0328b1209d157ef001c94dd85b4f8f64139adb0eac2659f4b08382b2f474d"
|
||||
dependencies = [
|
||||
"cfg-if",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "itoa"
|
||||
version = "0.4.7"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
|
||||
|
||||
[[package]]
|
||||
name = "lazy_static"
|
||||
version = "1.4.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
|
||||
|
||||
[[package]]
|
||||
name = "libc"
|
||||
version = "0.2.98"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "320cfe77175da3a483efed4bc0adc1968ca050b098ce4f2f1c13a56626128790"
|
||||
|
||||
[[package]]
|
||||
name = "lock_api"
|
||||
version = "0.4.4"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "0382880606dff6d15c9476c416d18690b72742aa7b605bb6dd6ec9030fbf07eb"
|
||||
dependencies = [
|
||||
"scopeguard",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "log"
|
||||
version = "0.4.14"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
|
||||
dependencies = [
|
||||
"cfg-if",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "matchers"
|
||||
version = "0.0.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "f099785f7595cc4b4553a174ce30dd7589ef93391ff414dbb67f62392b9e0ce1"
|
||||
dependencies = [
|
||||
"regex-automata",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "memchr"
|
||||
version = "2.4.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "b16bd47d9e329435e309c58469fe0791c2d0d1ba96ec0954152a5ae2b04387dc"
|
||||
|
||||
[[package]]
|
||||
name = "mini-redis"
|
||||
version = "0.4.1"
|
||||
dependencies = [
|
||||
"async-stream",
|
||||
"atoi",
|
||||
"bytes",
|
||||
"structopt",
|
||||
"tokio",
|
||||
"tokio-stream",
|
||||
"tracing",
|
||||
"tracing-futures",
|
||||
"tracing-subscriber",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "mio"
|
||||
version = "0.7.13"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "8c2bdb6314ec10835cd3293dd268473a835c02b7b352e788be788b3c6ca6bb16"
|
||||
dependencies = [
|
||||
"libc",
|
||||
"log",
|
||||
"miow",
|
||||
"ntapi",
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "miow"
|
||||
version = "0.3.7"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "b9f1c5b025cda876f66ef43a113f91ebc9f4ccef34843000e0adf6ebbab84e21"
|
||||
dependencies = [
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "ntapi"
|
||||
version = "0.3.6"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "3f6bb902e437b6d86e03cce10a7e2af662292c5dfef23b65899ea3ac9354ad44"
|
||||
dependencies = [
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "num-integer"
|
||||
version = "0.1.44"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
|
||||
dependencies = [
|
||||
"autocfg",
|
||||
"num-traits",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "num-traits"
|
||||
version = "0.2.14"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
|
||||
dependencies = [
|
||||
"autocfg",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "num_cpus"
|
||||
version = "1.13.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "05499f3756671c15885fee9034446956fff3f243d6077b91e5767df161f766b3"
|
||||
dependencies = [
|
||||
"hermit-abi",
|
||||
"libc",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "once_cell"
|
||||
version = "1.8.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
|
||||
|
||||
[[package]]
|
||||
name = "parking_lot"
|
||||
version = "0.11.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
|
||||
dependencies = [
|
||||
"instant",
|
||||
"lock_api",
|
||||
"parking_lot_core",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "parking_lot_core"
|
||||
version = "0.8.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "fa7a782938e745763fe6907fc6ba86946d72f49fe7e21de074e08128a99fb018"
|
||||
dependencies = [
|
||||
"cfg-if",
|
||||
"instant",
|
||||
"libc",
|
||||
"redox_syscall",
|
||||
"smallvec",
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "pin-project"
|
||||
version = "1.0.7"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "c7509cc106041c40a4518d2af7a61530e1eed0e6285296a3d8c5472806ccc4a4"
|
||||
dependencies = [
|
||||
"pin-project-internal",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "pin-project-internal"
|
||||
version = "1.0.7"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "48c950132583b500556b1efd71d45b319029f2b71518d979fcc208e16b42426f"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"syn",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "pin-project-lite"
|
||||
version = "0.2.7"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "8d31d11c69a6b52a174b42bdc0c30e5e11670f90788b2c471c31c1d17d449443"
|
||||
|
||||
[[package]]
|
||||
name = "proc-macro-error"
|
||||
version = "1.0.4"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
|
||||
dependencies = [
|
||||
"proc-macro-error-attr",
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"syn",
|
||||
"version_check",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "proc-macro-error-attr"
|
||||
version = "1.0.4"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"version_check",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "proc-macro2"
|
||||
version = "1.0.27"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "f0d8caf72986c1a598726adc988bb5984792ef84f5ee5aa50209145ee8077038"
|
||||
dependencies = [
|
||||
"unicode-xid",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "quote"
|
||||
version = "1.0.9"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "redox_syscall"
|
||||
version = "0.2.9"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "5ab49abadf3f9e1c4bc499e8845e152ad87d2ad2d30371841171169e9d75feee"
|
||||
dependencies = [
|
||||
"bitflags",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "regex"
|
||||
version = "1.5.4"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
|
||||
dependencies = [
|
||||
"regex-syntax",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "regex-automata"
|
||||
version = "0.1.10"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "6c230d73fb8d8c1b9c0b3135c5142a8acee3a0558fb8db5cf1cb65f8d7862132"
|
||||
dependencies = [
|
||||
"regex-syntax",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "regex-syntax"
|
||||
version = "0.6.25"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
|
||||
|
||||
[[package]]
|
||||
name = "ryu"
|
||||
version = "1.0.5"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
|
||||
|
||||
[[package]]
|
||||
name = "scopeguard"
|
||||
version = "1.1.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
|
||||
|
||||
[[package]]
|
||||
name = "serde"
|
||||
version = "1.0.126"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "ec7505abeacaec74ae4778d9d9328fe5a5d04253220a85c4ee022239fc996d03"
|
||||
|
||||
[[package]]
|
||||
name = "serde_json"
|
||||
version = "1.0.64"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
|
||||
dependencies = [
|
||||
"itoa",
|
||||
"ryu",
|
||||
"serde",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "sharded-slab"
|
||||
version = "0.1.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "79c719719ee05df97490f80a45acfc99e5a30ce98a1e4fb67aee422745ae14e3"
|
||||
dependencies = [
|
||||
"lazy_static",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "signal-hook-registry"
|
||||
version = "1.4.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "e51e73328dc4ac0c7ccbda3a494dfa03df1de2f46018127f60c693f2648455b0"
|
||||
dependencies = [
|
||||
"libc",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "smallvec"
|
||||
version = "1.6.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
|
||||
|
||||
[[package]]
|
||||
name = "strsim"
|
||||
version = "0.8.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
|
||||
|
||||
[[package]]
|
||||
name = "structopt"
|
||||
version = "0.3.22"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "69b041cdcb67226aca307e6e7be44c8806423d83e018bd662360a93dabce4d71"
|
||||
dependencies = [
|
||||
"clap",
|
||||
"lazy_static",
|
||||
"structopt-derive",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "structopt-derive"
|
||||
version = "0.4.15"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "7813934aecf5f51a54775e00068c237de98489463968231a51746bbbc03f9c10"
|
||||
dependencies = [
|
||||
"heck",
|
||||
"proc-macro-error",
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"syn",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "syn"
|
||||
version = "1.0.73"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "f71489ff30030d2ae598524f61326b902466f72a0fb1a8564c001cc63425bcc7"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"unicode-xid",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "textwrap"
|
||||
version = "0.11.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
|
||||
dependencies = [
|
||||
"unicode-width",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "thread_local"
|
||||
version = "1.1.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "8018d24e04c95ac8790716a5987d0fec4f8b27249ffa0f7d33f1369bdfb88cbd"
|
||||
dependencies = [
|
||||
"once_cell",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tokio"
|
||||
version = "1.8.1"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "98c8b05dc14c75ea83d63dd391100353789f5f24b8b3866542a5e85c8be8e985"
|
||||
dependencies = [
|
||||
"autocfg",
|
||||
"bytes",
|
||||
"libc",
|
||||
"memchr",
|
||||
"mio",
|
||||
"num_cpus",
|
||||
"once_cell",
|
||||
"parking_lot",
|
||||
"pin-project-lite",
|
||||
"signal-hook-registry",
|
||||
"tokio-macros",
|
||||
"winapi",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tokio-macros"
|
||||
version = "1.3.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "54473be61f4ebe4efd09cec9bd5d16fa51d70ea0192213d754d2d500457db110"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"syn",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tokio-stream"
|
||||
version = "0.1.7"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "7b2f3f698253f03119ac0102beaa64f67a67e08074d03a22d18784104543727f"
|
||||
dependencies = [
|
||||
"futures-core",
|
||||
"pin-project-lite",
|
||||
"tokio",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing"
|
||||
version = "0.1.26"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "09adeb8c97449311ccd28a427f96fb563e7fd31aabf994189879d9da2394b89d"
|
||||
dependencies = [
|
||||
"cfg-if",
|
||||
"pin-project-lite",
|
||||
"tracing-attributes",
|
||||
"tracing-core",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing-attributes"
|
||||
version = "0.1.15"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "c42e6fa53307c8a17e4ccd4dc81cf5ec38db9209f59b222210375b54ee40d1e2"
|
||||
dependencies = [
|
||||
"proc-macro2",
|
||||
"quote",
|
||||
"syn",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing-core"
|
||||
version = "0.1.18"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "a9ff14f98b1a4b289c6248a023c1c2fa1491062964e9fed67ab29c4e4da4a052"
|
||||
dependencies = [
|
||||
"lazy_static",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing-futures"
|
||||
version = "0.2.5"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "97d095ae15e245a057c8e8451bab9b3ee1e1f68e9ba2b4fbc18d0ac5237835f2"
|
||||
dependencies = [
|
||||
"pin-project",
|
||||
"tracing",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing-log"
|
||||
version = "0.1.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "a6923477a48e41c1951f1999ef8bb5a3023eb723ceadafe78ffb65dc366761e3"
|
||||
dependencies = [
|
||||
"lazy_static",
|
||||
"log",
|
||||
"tracing-core",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing-serde"
|
||||
version = "0.1.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "fb65ea441fbb84f9f6748fd496cf7f63ec9af5bca94dd86456978d055e8eb28b"
|
||||
dependencies = [
|
||||
"serde",
|
||||
"tracing-core",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tracing-subscriber"
|
||||
version = "0.2.19"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "ab69019741fca4d98be3c62d2b75254528b5432233fd8a4d2739fec20278de48"
|
||||
dependencies = [
|
||||
"ansi_term 0.12.1",
|
||||
"chrono",
|
||||
"lazy_static",
|
||||
"matchers",
|
||||
"regex",
|
||||
"serde",
|
||||
"serde_json",
|
||||
"sharded-slab",
|
||||
"smallvec",
|
||||
"thread_local",
|
||||
"tracing",
|
||||
"tracing-core",
|
||||
"tracing-log",
|
||||
"tracing-serde",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "unicode-segmentation"
|
||||
version = "1.8.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "8895849a949e7845e06bd6dc1aa51731a103c42707010a5b591c0038fb73385b"
|
||||
|
||||
[[package]]
|
||||
name = "unicode-width"
|
||||
version = "0.1.8"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
|
||||
|
||||
[[package]]
|
||||
name = "unicode-xid"
|
||||
version = "0.2.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
|
||||
|
||||
[[package]]
|
||||
name = "vec_map"
|
||||
version = "0.8.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
|
||||
|
||||
[[package]]
|
||||
name = "version_check"
|
||||
version = "0.9.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
|
||||
|
||||
[[package]]
|
||||
name = "winapi"
|
||||
version = "0.3.9"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
|
||||
dependencies = [
|
||||
"winapi-i686-pc-windows-gnu",
|
||||
"winapi-x86_64-pc-windows-gnu",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "winapi-i686-pc-windows-gnu"
|
||||
version = "0.4.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
|
||||
|
||||
[[package]]
|
||||
name = "winapi-x86_64-pc-windows-gnu"
|
||||
version = "0.4.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
|
||||
|
|
@ -0,0 +1,36 @@
|
|||
[package]
|
||||
authors = ["Carl Lerche <me@carllerche.com>"]
|
||||
edition = "2018"
|
||||
name = "mini-redis"
|
||||
version = "0.4.1"
|
||||
license = "MIT"
|
||||
readme = "README.md"
|
||||
documentation = "https://docs.rs/mini-redis/0.4.0/mini-redis/"
|
||||
repository = "https://github.com/tokio-rs/mini-redis"
|
||||
description = """
|
||||
An incomplete implementation of a Rust client and server. Used as a
|
||||
larger example of an idiomatic Tokio application.
|
||||
"""
|
||||
|
||||
[[bin]]
|
||||
name = "mini-redis-cli"
|
||||
path = "src/bin/cli.rs"
|
||||
|
||||
[[bin]]
|
||||
name = "mini-redis-server"
|
||||
path = "src/bin/server.rs"
|
||||
|
||||
[dependencies]
|
||||
async-stream = "0.3.0"
|
||||
atoi = "0.3.2"
|
||||
bytes = "1"
|
||||
structopt = "0.3.14"
|
||||
tokio = { version = "1", features = ["full"] }
|
||||
tokio-stream = "0.1"
|
||||
tracing = "0.1.13"
|
||||
tracing-futures = { version = "0.2.3" }
|
||||
tracing-subscriber = "0.2.2"
|
||||
|
||||
[dev-dependencies]
|
||||
# Enable test-utilities in dev mode only. This is mostly for tests.
|
||||
tokio = { version = "1", features = ["test-util"] }
|
||||
|
|
@ -0,0 +1,25 @@
|
|||
Copyright (c) 2020 Tokio Contributors
|
||||
|
||||
Permission is hereby granted, free of charge, to any
|
||||
person obtaining a copy of this software and associated
|
||||
documentation files (the "Software"), to deal in the
|
||||
Software without restriction, including without
|
||||
limitation the rights to use, copy, modify, merge,
|
||||
publish, distribute, sublicense, and/or sell copies of
|
||||
the Software, and to permit persons to whom the Software
|
||||
is furnished to do so, subject to the following
|
||||
conditions:
|
||||
|
||||
The above copyright notice and this permission notice
|
||||
shall be included in all copies or substantial portions
|
||||
of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
|
||||
ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
|
||||
TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
|
||||
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
|
||||
SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
||||
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
||||
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
|
||||
IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
||||
DEALINGS IN THE SOFTWARE.
|
||||
|
|
@ -0,0 +1,169 @@
|
|||
# mini-redis
|
||||
|
||||
本项目从[tokio/mini-redis](https://github.com/tokio-rs/mini-redis)fork而来，作为rust course的练习项目之一，**文档和注释还未进行翻译**，欢迎大家贡献。
|
||||
|
||||
|
||||
`mini-redis` is an incomplete, idiomatic implementation of a
|
||||
[Redis](https://redis.io) client and server built with
|
||||
[Tokio](https://tokio.rs).
|
||||
|
||||
The intent of this project is to provide a larger example of writing a Tokio
|
||||
application.
|
||||
|
||||
**Disclaimer** Please don't use mini-redis in production. This project is
|
||||
intended to be a learning resource, and omits various parts of the Redis
|
||||
protocol because implementing them would not introduce any new concepts. We will
|
||||
not add new features because you need them in your project — use one of the
|
||||
fully featured alternatives instead.
|
||||
|
||||
## Why Redis
|
||||
|
||||
The primary goal of this project is teaching Tokio. Doing this requires a
|
||||
project with a wide range of features with a focus on implementation simplicity.
|
||||
Redis, an in-memory database, provides a wide range of features and uses a
|
||||
simple wire protocol. The wide range of features allows demonstrating many Tokio
|
||||
patterns in a "real world" context.
|
||||
|
||||
The Redis wire protocol documentation can be found [here](https://redis.io/topics/protocol).
|
||||
|
||||
The set of commands Redis provides can be found
|
||||
[here](https://redis.io/commands).
|
||||
|
||||
|
||||
## Running
|
||||
|
||||
The repository provides a server, client library, and some client executables
|
||||
for interacting with the server.
|
||||
|
||||
Start the server:
|
||||
|
||||
```
|
||||
RUST_LOG=debug cargo run --bin mini-redis-server
|
||||
```
|
||||
|
||||
The [`tracing`](https://github.com/tokio-rs/tracing) crate is used to provide structured logs.
|
||||
You can substitute `debug` with the desired [log level][level].
|
||||
|
||||
[level]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives
|
||||
|
||||
Then, in a different terminal window, the various client [examples](examples)
|
||||
can be executed. For example:
|
||||
|
||||
```
|
||||
cargo run --example hello_world
|
||||
```
|
||||
|
||||
Additionally, a CLI client is provided to run arbitrary commands from the
|
||||
terminal. With the server running, the following works:
|
||||
|
||||
```
|
||||
cargo run --bin mini-redis-cli set foo bar
|
||||
|
||||
cargo run --bin mini-redis-cli get foo
|
||||
```
|
||||
|
||||
## Supported commands
|
||||
|
||||
`mini-redis` currently supports the following commands.
|
||||
|
||||
* [GET](https://redis.io/commands/get)
|
||||
* [SET](https://redis.io/commands/set)
|
||||
* [PUBLISH](https://redis.io/commands/publish)
|
||||
* [SUBSCRIBE](https://redis.io/commands/subscribe)
|
||||
|
||||
The Redis wire protocol specification can be found
|
||||
[here](https://redis.io/topics/protocol).
|
||||
|
||||
There is no support for persistence yet.
|
||||
|
||||
## Tokio patterns
|
||||
|
||||
The project demonstrates a number of useful patterns, including:
|
||||
|
||||
### TCP server
|
||||
|
||||
[`server.rs`](src/server.rs) starts a TCP server that accepts connections,
|
||||
and spawns a new task per connection. It gracefully handles `accept` errors.
|
||||
|
||||
### Client library
|
||||
|
||||
[`client.rs`](src/client.rs) shows how to model an asynchronous client. The
|
||||
various capabilities are exposed as `async` methods.
|
||||
|
||||
### State shared across sockets
|
||||
|
||||
The server maintains a [`Db`] instance that is accessible from all connected
|
||||
connections. The [`Db`] instance manages the key-value state as well as pub/sub
|
||||
capabilities.
|
||||
|
||||
[`Db`]: src/db.rs
|
||||
|
||||
### Framing
|
||||
|
||||
[`connection.rs`](src/connection.rs) and [`frame.rs`](src/frame.rs) show how to
|
||||
idiomatically implement a wire protocol. The protocol is modeled using an
|
||||
intermediate representation, the `Frame` structure. `Connection` takes a
|
||||
`TcpStream` and exposes an API that sends and receives `Frame` values.
|
||||
|
||||
### Graceful shutdown
|
||||
|
||||
The server implements graceful shutdown. [`tokio::signal`] is used to listen for
|
||||
a SIGINT. Once the signal is received, shutdown begins. The server stops
|
||||
accepting new connections. Existing connections are notified to shutdown
|
||||
gracefully. In-flight work is completed, and the connection is closed.
|
||||
|
||||
[`tokio::signal`]: https://docs.rs/tokio/*/tokio/signal/
|
||||
|
||||
### Concurrent connection limiting
|
||||
|
||||
The server uses a [`Semaphore`] limits the maximum number of concurrent
|
||||
connections. Once the limit is reached, the server stops accepting new
|
||||
connections until an existing one terminates.
|
||||
|
||||
[`Semaphore`]: https://docs.rs/tokio/*/tokio/sync/struct.Semaphore.html
|
||||
|
||||
### Pub/Sub
|
||||
|
||||
The server implements non-trivial pub/sub capability. The client may subscribe
|
||||
to multiple channels and update its subscription at any time. The server
|
||||
implements this using one [broadcast channel][broadcast] per channel and a
|
||||
[`StreamMap`] per connection. Clients are able to send subscription commands to
|
||||
the server to update the active subscriptions.
|
||||
|
||||
[broadcast]: https://docs.rs/tokio/*/tokio/sync/broadcast/index.html
|
||||
[`StreamMap`]: https://docs.rs/tokio/*/tokio/stream/struct.StreamMap.html
|
||||
|
||||
### Using a `std::sync::Mutex` in an async application
|
||||
|
||||
The server uses a `std::sync::Mutex` and **not** a Tokio mutex to synchronize
|
||||
access to shared state. See [`db.rs`](src/db.rs) for more details.
|
||||
|
||||
### Testing asynchronous code that relies on time
|
||||
|
||||
In [`tests/server.rs`](tests/server.rs), there are tests for key expiration.
|
||||
These tests depend on time passing. In order to make the tests deterministic,
|
||||
time is mocked out using Tokio's testing utilities.
|
||||
|
||||
## Contributing
|
||||
|
||||
Contributions to `mini-redis` are welcome. Keep in mind, the goal of the project
|
||||
is **not** to reach feature parity with real Redis, but to demonstrate
|
||||
asynchronous Rust patterns with Tokio.
|
||||
|
||||
Commands or other features should only be added if doing so is useful to
|
||||
demonstrate a new pattern.
|
||||
|
||||
Contributions should come with extensive comments targetted to new Tokio users.
|
||||
|
||||
Contributions that only focus on clarifying and improving comments are very
|
||||
welcome.
|
||||
|
||||
## License
|
||||
|
||||
This project is licensed under the [MIT license](LICENSE).
|
||||
|
||||
### Contribution
|
||||
|
||||
Unless you explicitly state otherwise, any contribution intentionally submitted
|
||||
for inclusion in `mini-redis` by you, shall be licensed as MIT, without any
|
||||
additional terms or conditions.
|
||||
|
|
@ -0,0 +1,4 @@
|
|||
#[tokio::main]
|
||||
async fn main() {
|
||||
unimplemented!();
|
||||
}
|
||||
|
|
@ -0,0 +1,32 @@
|
|||
//! Hello world server.
|
||||
//!
|
||||
//! A simple client that connects to a mini-redis server, sets key "hello" with value "world",
|
||||
//! and gets it from the server after
|
||||
//!
|
||||
//! You can test this out by running:
|
||||
//!
|
||||
//! cargo run --bin mini-redis-server
|
||||
//!
|
||||
//! And then in another terminal run:
|
||||
//!
|
||||
//! cargo run --example hello_world
|
||||
|
||||
#![warn(rust_2018_idioms)]
|
||||
|
||||
use mini_redis::{client, Result};
|
||||
|
||||
#[tokio::main]
|
||||
pub async fn main() -> Result<()> {
|
||||
// Open a connection to the mini-redis address.
|
||||
let mut client = client::connect("127.0.0.1:6379").await?;
|
||||
|
||||
// Set the key "hello" with value "world"
|
||||
client.set("hello", "world".into()).await?;
|
||||
|
||||
// Get key "hello"
|
||||
let result = client.get("hello").await?;
|
||||
|
||||
println!("got value from the server; success={:?}", result.is_some());
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
|
@ -0,0 +1,31 @@
|
|||
//! Publish to a redis channel example.
|
||||
//!
|
||||
//! A simple client that connects to a mini-redis server, and
|
||||
//! publishes a message on `foo` channel
|
||||
//!
|
||||
//! You can test this out by running:
|
||||
//!
|
||||
//! cargo run --bin mini-redis-server
|
||||
//!
|
||||
//! Then in another terminal run:
|
||||
//!
|
||||
//! cargo run --example sub
|
||||
//!
|
||||
//! And then in another terminal run:
|
||||
//!
|
||||
//! cargo run --example pub
|
||||
|
||||
#![warn(rust_2018_idioms)]
|
||||
|
||||
use mini_redis::{client, Result};
|
||||
|
||||
#[tokio::main]
|
||||
async fn main() -> Result<()> {
|
||||
// Open a connection to the mini-redis address.
|
||||
let mut client = client::connect("127.0.0.1:6379").await?;
|
||||
|
||||
// publish message `bar` on channel foo
|
||||
client.publish("foo", "bar".into()).await?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
|
@ -0,0 +1,37 @@
|
|||
//! Subscribe to a redis channel example.
|
||||
//!
|
||||
//! A simple client that connects to a mini-redis server, subscribes to "foo" and "bar" channels
|
||||
//! and awaits messages published on those channels
|
||||
//!
|
||||
//! You can test this out by running:
|
||||
//!
|
||||
//! cargo run --bin mini-redis-server
|
||||
//!
|
||||
//! Then in another terminal run:
|
||||
//!
|
||||
//! cargo run --example sub
|
||||
//!
|
||||
//! And then in another terminal run:
|
||||
//!
|
||||
//! cargo run --example pub
|
||||
|
||||
|
||||
|
||||
use mini_redis::{client, Result};
|
||||
use tokio_stream::StreamExt;
|
||||
#[tokio::main]
|
||||
pub async fn main() -> Result<()> {
|
||||
// Open a connection to the mini-redis address.
|
||||
let client = client::connect("127.0.0.1:6379").await?;
|
||||
|
||||
// subscribe to channel foo
|
||||
let mut subscriber = client.subscribe(vec!["foo".into()]).await?;
|
||||
let messages = subscriber.into_stream();
|
||||
tokio::pin!(messages);
|
||||
// await messages on channel foo
|
||||
while let Some(msg) = messages.next().await {
|
||||
println!("got = {:?}", msg);
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
|
@ -0,0 +1,108 @@
|
|||
use mini_redis::{client, DEFAULT_PORT};
|
||||
|
||||
use bytes::Bytes;
|
||||
use std::num::ParseIntError;
|
||||
use std::str;
|
||||
use std::time::Duration;
|
||||
use structopt::StructOpt;
|
||||
|
||||
#[derive(StructOpt, Debug)]
|
||||
#[structopt(name = "mini-redis-cli", author = env!("CARGO_PKG_AUTHORS"), about = "Issue Redis commands")]
|
||||
struct Cli {
|
||||
#[structopt(subcommand)]
|
||||
command: Command,
|
||||
|
||||
#[structopt(name = "hostname", long = "--host", default_value = "127.0.0.1")]
|
||||
host: String,
|
||||
|
||||
#[structopt(name = "port", long = "--port", default_value = DEFAULT_PORT)]
|
||||
port: String,
|
||||
}
|
||||
|
||||
#[derive(StructOpt, Debug)]
|
||||
enum Command {
|
||||
/// Get the value of key.
|
||||
Get {
|
||||
/// Name of key to get
|
||||
key: String,
|
||||
},
|
||||
/// Set key to hold the string value.
|
||||
Set {
|
||||
/// Name of key to set
|
||||
key: String,
|
||||
|
||||
/// Value to set.
|
||||
#[structopt(parse(from_str = bytes_from_str))]
|
||||
value: Bytes,
|
||||
|
||||
/// Expire the value after specified amount of time
|
||||
#[structopt(parse(try_from_str = duration_from_ms_str))]
|
||||
expires: Option<Duration>,
|
||||
},
|
||||
}
|
||||
|
||||
/// Entry point for CLI tool.
|
||||
///
|
||||
/// The `[tokio::main]` annotation signals that the Tokio runtime should be
|
||||
/// started when the function is called. The body of the function is executed
|
||||
/// within the newly spawned runtime.
|
||||
///
|
||||
/// `flavor = "current_thread"` is used here to avoid spawning background
|
||||
/// threads. The CLI tool use case benefits more by being lighter instead of
|
||||
/// multi-threaded.
|
||||
#[tokio::main(flavor = "current_thread")]
|
||||
async fn main() -> mini_redis::Result<()> {
|
||||
// Enable logging
|
||||
tracing_subscriber::fmt::try_init()?;
|
||||
|
||||
// Parse command line arguments
|
||||
let cli = Cli::from_args();
|
||||
|
||||
// Get the remote address to connect to
|
||||
let addr = format!("{}:{}", cli.host, cli.port);
|
||||
|
||||
// Establish a connection
|
||||
let mut client = client::connect(&addr).await?;
|
||||
|
||||
// Process the requested command
|
||||
match cli.command {
|
||||
Command::Get { key } => {
|
||||
if let Some(value) = client.get(&key).await? {
|
||||
if let Ok(string) = str::from_utf8(&value) {
|
||||
println!("\"{}\"", string);
|
||||
} else {
|
||||
println!("{:?}", value);
|
||||
}
|
||||
} else {
|
||||
println!("(nil)");
|
||||
}
|
||||
}
|
||||
Command::Set {
|
||||
key,
|
||||
value,
|
||||
expires: None,
|
||||
} => {
|
||||
client.set(&key, value).await?;
|
||||
println!("OK");
|
||||
}
|
||||
Command::Set {
|
||||
key,
|
||||
value,
|
||||
expires: Some(expires),
|
||||
} => {
|
||||
client.set_expires(&key, value, expires).await?;
|
||||
println!("OK");
|
||||
}
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
fn duration_from_ms_str(src: &str) -> Result<Duration, ParseIntError> {
|
||||
let ms = src.parse::<u64>()?;
|
||||
Ok(Duration::from_millis(ms))
|
||||
}
|
||||
|
||||
fn bytes_from_str(src: &str) -> Bytes {
|
||||
Bytes::from(src.to_string())
|
||||
}
|
||||
|
|
@ -0,0 +1,37 @@
|
|||
//! mini-redis server.
|
||||
//!
|
||||
//! This file is the entry point for the server implemented in the library. It
|
||||
//! performs command line parsing and passes the arguments on to
|
||||
//! `mini_redis::server`.
|
||||
//!
|
||||
//! The `clap` crate is used for parsing arguments.
|
||||
|
||||
use mini_redis::{server, DEFAULT_PORT};
|
||||
|
||||
use structopt::StructOpt;
|
||||
use tokio::net::TcpListener;
|
||||
use tokio::signal;
|
||||
|
||||
#[tokio::main]
|
||||
pub async fn main() -> mini_redis::Result<()> {
|
||||
// enable logging
|
||||
// see https://docs.rs/tracing for more info
|
||||
tracing_subscriber::fmt::try_init()?;
|
||||
|
||||
let cli = Cli::from_args();
|
||||
let port = cli.port.as_deref().unwrap_or(DEFAULT_PORT);
|
||||
|
||||
// Bind a TCP listener
|
||||
let listener = TcpListener::bind(&format!("127.0.0.1:{}", port)).await?;
|
||||
|
||||
server::run(listener, signal::ctrl_c()).await;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
#[derive(StructOpt, Debug)]
|
||||
#[structopt(name = "mini-redis-server", version = env!("CARGO_PKG_VERSION"), author = env!("CARGO_PKG_AUTHORS"), about = "A Redis server")]
|
||||
struct Cli {
|
||||
#[structopt(name = "port", long = "--port")]
|
||||
port: Option<String>,
|
||||
}
|
||||
|
|
@ -0,0 +1,264 @@
|
|||
//! Minimal blocking Redis client implementation
|
||||
//!
|
||||
//! Provides a blocking connect and methods for issuing the supported commands.
|
||||
|
||||
use bytes::Bytes;
|
||||
use std::time::Duration;
|
||||
use tokio::net::ToSocketAddrs;
|
||||
use tokio::runtime::Runtime;
|
||||
|
||||
pub use crate::client::Message;
|
||||
|
||||
/// Established connection with a Redis server.
|
||||
///
|
||||
/// Backed by a single `TcpStream`, `BlockingClient` provides basic network
|
||||
/// client functionality (no pooling, retrying, ...). Connections are
|
||||
/// established using the [`connect`](fn@connect) function.
|
||||
///
|
||||
/// Requests are issued using the various methods of `Client`.
|
||||
pub struct BlockingClient {
|
||||
/// The asynchronous `Client`.
|
||||
inner: crate::client::Client,
|
||||
|
||||
/// A `current_thread` runtime for executing operations on the asynchronous
|
||||
/// client in a blocking manner.
|
||||
rt: Runtime,
|
||||
}
|
||||
|
||||
/// A client that has entered pub/sub mode.
|
||||
///
|
||||
/// Once clients subscribe to a channel, they may only perform pub/sub related
|
||||
/// commands. The `BlockingClient` type is transitioned to a
|
||||
/// `BlockingSubscriber` type in order to prevent non-pub/sub methods from being
|
||||
/// called.
|
||||
pub struct BlockingSubscriber {
|
||||
/// The asynchronous `Subscriber`.
|
||||
inner: crate::client::Subscriber,
|
||||
|
||||
/// A `current_thread` runtime for executing operations on the asynchronous
|
||||
/// `Subscriber` in a blocking manner.
|
||||
rt: Runtime,
|
||||
}
|
||||
|
||||
/// The iterator returned by `Subscriber::into_iter`.
|
||||
struct SubscriberIterator {
|
||||
/// The asynchronous `Subscriber`.
|
||||
inner: crate::client::Subscriber,
|
||||
|
||||
/// A `current_thread` runtime for executing operations on the asynchronous
|
||||
/// `Subscriber` in a blocking manner.
|
||||
rt: Runtime,
|
||||
}
|
||||
|
||||
/// Establish a connection with the Redis server located at `addr`.
|
||||
///
|
||||
/// `addr` may be any type that can be asynchronously converted to a
|
||||
/// `SocketAddr`. This includes `SocketAddr` and strings. The `ToSocketAddrs`
|
||||
/// trait is the Tokio version and not the `std` version.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::blocking_client;
|
||||
///
|
||||
/// fn main() {
|
||||
/// let client = match blocking_client::connect("localhost:6379") {
|
||||
/// Ok(client) => client,
|
||||
/// Err(_) => panic!("failed to establish connection"),
|
||||
/// };
|
||||
/// # drop(client);
|
||||
/// }
|
||||
/// ```
|
||||
pub fn connect<T: ToSocketAddrs>(addr: T) -> crate::Result<BlockingClient> {
|
||||
let rt = tokio::runtime::Builder::new_current_thread()
|
||||
.enable_all()
|
||||
.build()?;
|
||||
|
||||
let inner = rt.block_on(crate::client::connect(addr))?;
|
||||
|
||||
Ok(BlockingClient { inner, rt })
|
||||
}
|
||||
|
||||
impl BlockingClient {
|
||||
/// Get the value of key.
|
||||
///
|
||||
/// If the key does not exist the special value `None` is returned.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::blocking_client;
|
||||
///
|
||||
/// fn main() {
|
||||
/// let mut client = blocking_client::connect("localhost:6379").unwrap();
|
||||
///
|
||||
/// let val = client.get("foo").unwrap();
|
||||
/// println!("Got = {:?}", val);
|
||||
/// }
|
||||
/// ```
|
||||
pub fn get(&mut self, key: &str) -> crate::Result<Option<Bytes>> {
|
||||
self.rt.block_on(self.inner.get(key))
|
||||
}
|
||||
|
||||
/// Set `key` to hold the given `value`.
|
||||
///
|
||||
/// The `value` is associated with `key` until it is overwritten by the next
|
||||
/// call to `set` or it is removed.
|
||||
///
|
||||
/// If key already holds a value, it is overwritten. Any previous time to
|
||||
/// live associated with the key is discarded on successful SET operation.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::blocking_client;
|
||||
///
|
||||
/// fn main() {
|
||||
/// let mut client = blocking_client::connect("localhost:6379").unwrap();
|
||||
///
|
||||
/// client.set("foo", "bar".into()).unwrap();
|
||||
///
|
||||
/// // Getting the value immediately works
|
||||
/// let val = client.get("foo").unwrap().unwrap();
|
||||
/// assert_eq!(val, "bar");
|
||||
/// }
|
||||
/// ```
|
||||
pub fn set(&mut self, key: &str, value: Bytes) -> crate::Result<()> {
|
||||
self.rt.block_on(self.inner.set(key, value))
|
||||
}
|
||||
|
||||
/// Set `key` to hold the given `value`. The value expires after `expiration`
|
||||
///
|
||||
/// The `value` is associated with `key` until one of the following:
|
||||
/// - it expires.
|
||||
/// - it is overwritten by the next call to `set`.
|
||||
/// - it is removed.
|
||||
///
|
||||
/// If key already holds a value, it is overwritten. Any previous time to
|
||||
/// live associated with the key is discarded on a successful SET operation.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage. This example is not **guaranteed** to always
|
||||
/// work as it relies on time based logic and assumes the client and server
|
||||
/// stay relatively synchronized in time. The real world tends to not be so
|
||||
/// favorable.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::blocking_client;
|
||||
/// use std::thread;
|
||||
/// use std::time::Duration;
|
||||
///
|
||||
/// fn main() {
|
||||
/// let ttl = Duration::from_millis(500);
|
||||
/// let mut client = blocking_client::connect("localhost:6379").unwrap();
|
||||
///
|
||||
/// client.set_expires("foo", "bar".into(), ttl).unwrap();
|
||||
///
|
||||
/// // Getting the value immediately works
|
||||
/// let val = client.get("foo").unwrap().unwrap();
|
||||
/// assert_eq!(val, "bar");
|
||||
///
|
||||
/// // Wait for the TTL to expire
|
||||
/// thread::sleep(ttl);
|
||||
///
|
||||
/// let val = client.get("foo").unwrap();
|
||||
/// assert!(val.is_some());
|
||||
/// }
|
||||
/// ```
|
||||
pub fn set_expires(
|
||||
&mut self,
|
||||
key: &str,
|
||||
value: Bytes,
|
||||
expiration: Duration,
|
||||
) -> crate::Result<()> {
|
||||
self.rt
|
||||
.block_on(self.inner.set_expires(key, value, expiration))
|
||||
}
|
||||
|
||||
/// Posts `message` to the given `channel`.
|
||||
///
|
||||
/// Returns the number of subscribers currently listening on the channel.
|
||||
/// There is no guarantee that these subscribers receive the message as they
|
||||
/// may disconnect at any time.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::blocking_client;
|
||||
///
|
||||
/// fn main() {
|
||||
/// let mut client = blocking_client::connect("localhost:6379").unwrap();
|
||||
///
|
||||
/// let val = client.publish("foo", "bar".into()).unwrap();
|
||||
/// println!("Got = {:?}", val);
|
||||
/// }
|
||||
/// ```
|
||||
pub fn publish(&mut self, channel: &str, message: Bytes) -> crate::Result<u64> {
|
||||
self.rt.block_on(self.inner.publish(channel, message))
|
||||
}
|
||||
|
||||
/// Subscribes the client to the specified channels.
|
||||
///
|
||||
/// Once a client issues a subscribe command, it may no longer issue any
|
||||
/// non-pub/sub commands. The function consumes `self` and returns a
|
||||
/// `BlockingSubscriber`.
|
||||
///
|
||||
/// The `BlockingSubscriber` value is used to receive messages as well as
|
||||
/// manage the list of channels the client is subscribed to.
|
||||
pub fn subscribe(self, channels: Vec<String>) -> crate::Result<BlockingSubscriber> {
|
||||
let subscriber = self.rt.block_on(self.inner.subscribe(channels))?;
|
||||
Ok(BlockingSubscriber {
|
||||
inner: subscriber,
|
||||
rt: self.rt,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
impl BlockingSubscriber {
|
||||
/// Returns the set of channels currently subscribed to.
|
||||
pub fn get_subscribed(&self) -> &[String] {
|
||||
self.inner.get_subscribed()
|
||||
}
|
||||
|
||||
/// Receive the next message published on a subscribed channel, waiting if
|
||||
/// necessary.
|
||||
///
|
||||
/// `None` indicates the subscription has been terminated.
|
||||
pub fn next_message(&mut self) -> crate::Result<Option<Message>> {
|
||||
self.rt.block_on(self.inner.next_message())
|
||||
}
|
||||
|
||||
/// Convert the subscriber into an `Iterator` yielding new messages published
|
||||
/// on subscribed channels.
|
||||
pub fn into_iter(self) -> impl Iterator<Item = crate::Result<Message>> {
|
||||
SubscriberIterator {
|
||||
inner: self.inner,
|
||||
rt: self.rt,
|
||||
}
|
||||
}
|
||||
|
||||
/// Subscribe to a list of new channels
|
||||
pub fn subscribe(&mut self, channels: &[String]) -> crate::Result<()> {
|
||||
self.rt.block_on(self.inner.subscribe(channels))
|
||||
}
|
||||
|
||||
/// Unsubscribe to a list of new channels
|
||||
pub fn unsubscribe(&mut self, channels: &[String]) -> crate::Result<()> {
|
||||
self.rt.block_on(self.inner.unsubscribe(channels))
|
||||
}
|
||||
}
|
||||
|
||||
impl Iterator for SubscriberIterator {
|
||||
type Item = crate::Result<Message>;
|
||||
|
||||
fn next(&mut self) -> Option<crate::Result<Message>> {
|
||||
self.rt.block_on(self.inner.next_message()).transpose()
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,120 @@
|
|||
use crate::client::Client;
|
||||
use crate::Result;
|
||||
|
||||
use bytes::Bytes;
|
||||
use tokio::sync::mpsc::{channel, Receiver, Sender};
|
||||
use tokio::sync::oneshot;
|
||||
|
||||
/// Create a new client request buffer
|
||||
///
|
||||
/// The `Client` performs Redis commands directly on the TCP connection. Only a
|
||||
/// single request may be in-flight at a given time and operations require
|
||||
/// mutable access to the `Client` handle. This prevents using a single Redis
|
||||
/// connection from multiple Tokio tasks.
|
||||
///
|
||||
/// The strategy for dealing with this class of problem is to spawn a dedicated
|
||||
/// Tokio task to manage the Redis connection and using "message passing" to
|
||||
/// operate on the connection. Commands are pushed into a channel. The
|
||||
/// connection task pops commands off of the channel and applies them to the
|
||||
/// Redis connection. When the response is received, it is forwarded to the
|
||||
/// original requester.
|
||||
///
|
||||
/// The returned `Buffer` handle may be cloned before passing the new handle to
|
||||
/// separate tasks.
|
||||
pub fn buffer(client: Client) -> Buffer {
|
||||
// Setting the message limit to a hard coded value of 32. in a real-app, the
|
||||
// buffer size should be configurable, but we don't need to do that here.
|
||||
let (tx, rx) = channel(32);
|
||||
|
||||
// Spawn a task to process requests for the connection.
|
||||
tokio::spawn(async move { run(client, rx).await });
|
||||
|
||||
// Return the `Buffer` handle.
|
||||
Buffer { tx }
|
||||
}
|
||||
|
||||
// Enum used to message pass the requested command from the `Buffer` handle
|
||||
#[derive(Debug)]
|
||||
enum Command {
|
||||
Get(String),
|
||||
Set(String, Bytes),
|
||||
}
|
||||
|
||||
// Message type sent over the channel to the connection task.
|
||||
//
|
||||
// `Command` is the command to forward to the connection.
|
||||
//
|
||||
// `oneshot::Sender` is a channel type that sends a **single** value. It is used
|
||||
// here to send the response received from the connection back to the original
|
||||
// requester.
|
||||
type Message = (Command, oneshot::Sender<Result<Option<Bytes>>>);
|
||||
|
||||
/// Receive commands sent through the channel and forward them to client. The
|
||||
/// response is returned back to the caller via a `oneshot`.
|
||||
async fn run(mut client: Client, mut rx: Receiver<Message>) {
|
||||
// Repeatedly pop messages from the channel. A return value of `None`
|
||||
// indicates that all `Buffer` handles have dropped and there will never be
|
||||
// another message sent on the channel.
|
||||
while let Some((cmd, tx)) = rx.recv().await {
|
||||
// The command is forwarded to the connection
|
||||
let response = match cmd {
|
||||
Command::Get(key) => client.get(&key).await,
|
||||
Command::Set(key, value) => client.set(&key, value).await.map(|_| None),
|
||||
};
|
||||
|
||||
// Send the response back to the caller.
|
||||
//
|
||||
// Failing to send the message indicates the `rx` half dropped
|
||||
// before receiving the message. This is a normal runtime event.
|
||||
let _ = tx.send(response);
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Clone)]
|
||||
pub struct Buffer {
|
||||
tx: Sender<Message>,
|
||||
}
|
||||
|
||||
impl Buffer {
|
||||
/// Get the value of a key.
|
||||
///
|
||||
/// Same as `Client::get` but requests are **buffered** until the associated
|
||||
/// connection has the ability to send the request.
|
||||
pub async fn get(&mut self, key: &str) -> Result<Option<Bytes>> {
|
||||
// Initialize a new `Get` command to send via the channel.
|
||||
let get = Command::Get(key.into());
|
||||
|
||||
// Initialize a new oneshot to be used to receive the response back from the connection.
|
||||
let (tx, rx) = oneshot::channel();
|
||||
|
||||
// Send the request
|
||||
self.tx.send((get, tx)).await?;
|
||||
|
||||
// Await the response
|
||||
match rx.await {
|
||||
Ok(res) => res,
|
||||
Err(err) => Err(err.into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Set `key` to hold the given `value`.
|
||||
///
|
||||
/// Same as `Client::set` but requests are **buffered** until the associated
|
||||
/// connection has the ability to send the request
|
||||
pub async fn set(&mut self, key: &str, value: Bytes) -> Result<()> {
|
||||
// Initialize a new `Set` command to send via the channel.
|
||||
let set = Command::Set(key.into(), value);
|
||||
|
||||
// Initialize a new oneshot to be used to receive the response back from the connection.
|
||||
let (tx, rx) = oneshot::channel();
|
||||
|
||||
// Send the request
|
||||
self.tx.send((set, tx)).await?;
|
||||
|
||||
// Await the response
|
||||
match rx.await {
|
||||
Ok(res) => res.map(|_| ()),
|
||||
Err(err) => Err(err.into()),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,473 @@
|
|||
//! Minimal Redis client implementation
|
||||
//!
|
||||
//! Provides an async connect and methods for issuing the supported commands.
|
||||
|
||||
use crate::cmd::{Get, Publish, Set, Subscribe, Unsubscribe};
|
||||
use crate::{Connection, Frame};
|
||||
|
||||
use async_stream::try_stream;
|
||||
use bytes::Bytes;
|
||||
use std::io::{Error, ErrorKind};
|
||||
use std::time::Duration;
|
||||
use tokio::net::{TcpStream, ToSocketAddrs};
|
||||
use tokio_stream::Stream;
|
||||
use tracing::{debug, instrument};
|
||||
|
||||
/// Established connection with a Redis server.
|
||||
///
|
||||
/// Backed by a single `TcpStream`, `Client` provides basic network client
|
||||
/// functionality (no pooling, retrying, ...). Connections are established using
|
||||
/// the [`connect`](fn@connect) function.
|
||||
///
|
||||
/// Requests are issued using the various methods of `Client`.
|
||||
pub struct Client {
|
||||
/// The TCP connection decorated with the redis protocol encoder / decoder
|
||||
/// implemented using a buffered `TcpStream`.
|
||||
///
|
||||
/// When `Listener` receives an inbound connection, the `TcpStream` is
|
||||
/// passed to `Connection::new`, which initializes the associated buffers.
|
||||
/// `Connection` allows the handler to operate at the "frame" level and keep
|
||||
/// the byte level protocol parsing details encapsulated in `Connection`.
|
||||
connection: Connection,
|
||||
}
|
||||
|
||||
/// A client that has entered pub/sub mode.
|
||||
///
|
||||
/// Once clients subscribe to a channel, they may only perform pub/sub related
|
||||
/// commands. The `Client` type is transitioned to a `Subscriber` type in order
|
||||
/// to prevent non-pub/sub methods from being called.
|
||||
pub struct Subscriber {
|
||||
/// The subscribed client.
|
||||
client: Client,
|
||||
|
||||
/// The set of channels to which the `Subscriber` is currently subscribed.
|
||||
subscribed_channels: Vec<String>,
|
||||
}
|
||||
|
||||
/// A message received on a subscribed channel.
|
||||
#[derive(Debug, Clone)]
|
||||
pub struct Message {
|
||||
pub channel: String,
|
||||
pub content: Bytes,
|
||||
}
|
||||
|
||||
/// Establish a connection with the Redis server located at `addr`.
|
||||
///
|
||||
/// `addr` may be any type that can be asynchronously converted to a
|
||||
/// `SocketAddr`. This includes `SocketAddr` and strings. The `ToSocketAddrs`
|
||||
/// trait is the Tokio version and not the `std` version.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::client;
|
||||
///
|
||||
/// #[tokio::main]
|
||||
/// async fn main() {
|
||||
/// let client = match client::connect("localhost:6379").await {
|
||||
/// Ok(client) => client,
|
||||
/// Err(_) => panic!("failed to establish connection"),
|
||||
/// };
|
||||
/// # drop(client);
|
||||
/// }
|
||||
/// ```
|
||||
///
|
||||
pub async fn connect<T: ToSocketAddrs>(addr: T) -> crate::Result<Client> {
|
||||
// The `addr` argument is passed directly to `TcpStream::connect`. This
|
||||
// performs any asynchronous DNS lookup and attempts to establish the TCP
|
||||
// connection. An error at either step returns an error, which is then
|
||||
// bubbled up to the caller of `mini_redis` connect.
|
||||
let socket = TcpStream::connect(addr).await?;
|
||||
|
||||
// Initialize the connection state. This allocates read/write buffers to
|
||||
// perform redis protocol frame parsing.
|
||||
let connection = Connection::new(socket);
|
||||
|
||||
Ok(Client { connection })
|
||||
}
|
||||
|
||||
impl Client {
|
||||
/// Get the value of key.
|
||||
///
|
||||
/// If the key does not exist the special value `None` is returned.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::client;
|
||||
///
|
||||
/// #[tokio::main]
|
||||
/// async fn main() {
|
||||
/// let mut client = client::connect("localhost:6379").await.unwrap();
|
||||
///
|
||||
/// let val = client.get("foo").await.unwrap();
|
||||
/// println!("Got = {:?}", val);
|
||||
/// }
|
||||
/// ```
|
||||
#[instrument(skip(self))]
|
||||
pub async fn get(&mut self, key: &str) -> crate::Result<Option<Bytes>> {
|
||||
// Create a `Get` command for the `key` and convert it to a frame.
|
||||
let frame = Get::new(key).into_frame();
|
||||
|
||||
debug!(request = ?frame);
|
||||
|
||||
// Write the frame to the socket. This writes the full frame to the
|
||||
// socket, waiting if necessary.
|
||||
self.connection.write_frame(&frame).await?;
|
||||
|
||||
// Wait for the response from the server
|
||||
//
|
||||
// Both `Simple` and `Bulk` frames are accepted. `Null` represents the
|
||||
// key not being present and `None` is returned.
|
||||
match self.read_response().await? {
|
||||
Frame::Simple(value) => Ok(Some(value.into())),
|
||||
Frame::Bulk(value) => Ok(Some(value)),
|
||||
Frame::Null => Ok(None),
|
||||
frame => Err(frame.to_error()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Set `key` to hold the given `value`.
|
||||
///
|
||||
/// The `value` is associated with `key` until it is overwritten by the next
|
||||
/// call to `set` or it is removed.
|
||||
///
|
||||
/// If key already holds a value, it is overwritten. Any previous time to
|
||||
/// live associated with the key is discarded on successful SET operation.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::client;
|
||||
///
|
||||
/// #[tokio::main]
|
||||
/// async fn main() {
|
||||
/// let mut client = client::connect("localhost:6379").await.unwrap();
|
||||
///
|
||||
/// client.set("foo", "bar".into()).await.unwrap();
|
||||
///
|
||||
/// // Getting the value immediately works
|
||||
/// let val = client.get("foo").await.unwrap().unwrap();
|
||||
/// assert_eq!(val, "bar");
|
||||
/// }
|
||||
/// ```
|
||||
#[instrument(skip(self))]
|
||||
pub async fn set(&mut self, key: &str, value: Bytes) -> crate::Result<()> {
|
||||
// Create a `Set` command and pass it to `set_cmd`. A separate method is
|
||||
// used to set a value with an expiration. The common parts of both
|
||||
// functions are implemented by `set_cmd`.
|
||||
self.set_cmd(Set::new(key, value, None)).await
|
||||
}
|
||||
|
||||
/// Set `key` to hold the given `value`. The value expires after `expiration`
|
||||
///
|
||||
/// The `value` is associated with `key` until one of the following:
|
||||
/// - it expires.
|
||||
/// - it is overwritten by the next call to `set`.
|
||||
/// - it is removed.
|
||||
///
|
||||
/// If key already holds a value, it is overwritten. Any previous time to
|
||||
/// live associated with the key is discarded on a successful SET operation.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage. This example is not **guaranteed** to always
|
||||
/// work as it relies on time based logic and assumes the client and server
|
||||
/// stay relatively synchronized in time. The real world tends to not be so
|
||||
/// favorable.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::client;
|
||||
/// use tokio::time;
|
||||
/// use std::time::Duration;
|
||||
///
|
||||
/// #[tokio::main]
|
||||
/// async fn main() {
|
||||
/// let ttl = Duration::from_millis(500);
|
||||
/// let mut client = client::connect("localhost:6379").await.unwrap();
|
||||
///
|
||||
/// client.set_expires("foo", "bar".into(), ttl).await.unwrap();
|
||||
///
|
||||
/// // Getting the value immediately works
|
||||
/// let val = client.get("foo").await.unwrap().unwrap();
|
||||
/// assert_eq!(val, "bar");
|
||||
///
|
||||
/// // Wait for the TTL to expire
|
||||
/// time::sleep(ttl).await;
|
||||
///
|
||||
/// let val = client.get("foo").await.unwrap();
|
||||
/// assert!(val.is_some());
|
||||
/// }
|
||||
/// ```
|
||||
#[instrument(skip(self))]
|
||||
pub async fn set_expires(
|
||||
&mut self,
|
||||
key: &str,
|
||||
value: Bytes,
|
||||
expiration: Duration,
|
||||
) -> crate::Result<()> {
|
||||
// Create a `Set` command and pass it to `set_cmd`. A separate method is
|
||||
// used to set a value with an expiration. The common parts of both
|
||||
// functions are implemented by `set_cmd`.
|
||||
self.set_cmd(Set::new(key, value, Some(expiration))).await
|
||||
}
|
||||
|
||||
/// The core `SET` logic, used by both `set` and `set_expires.
|
||||
async fn set_cmd(&mut self, cmd: Set) -> crate::Result<()> {
|
||||
// Convert the `Set` command into a frame
|
||||
let frame = cmd.into_frame();
|
||||
|
||||
debug!(request = ?frame);
|
||||
|
||||
// Write the frame to the socket. This writes the full frame to the
|
||||
// socket, waiting if necessary.
|
||||
self.connection.write_frame(&frame).await?;
|
||||
|
||||
// Wait for the response from the server. On success, the server
|
||||
// responds simply with `OK`. Any other response indicates an error.
|
||||
match self.read_response().await? {
|
||||
Frame::Simple(response) if response == "OK" => Ok(()),
|
||||
frame => Err(frame.to_error()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Posts `message` to the given `channel`.
|
||||
///
|
||||
/// Returns the number of subscribers currently listening on the channel.
|
||||
/// There is no guarantee that these subscribers receive the message as they
|
||||
/// may disconnect at any time.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// Demonstrates basic usage.
|
||||
///
|
||||
/// ```no_run
|
||||
/// use mini_redis::client;
|
||||
///
|
||||
/// #[tokio::main]
|
||||
/// async fn main() {
|
||||
/// let mut client = client::connect("localhost:6379").await.unwrap();
|
||||
///
|
||||
/// let val = client.publish("foo", "bar".into()).await.unwrap();
|
||||
/// println!("Got = {:?}", val);
|
||||
/// }
|
||||
/// ```
|
||||
#[instrument(skip(self))]
|
||||
pub async fn publish(&mut self, channel: &str, message: Bytes) -> crate::Result<u64> {
|
||||
// Convert the `Publish` command into a frame
|
||||
let frame = Publish::new(channel, message).into_frame();
|
||||
|
||||
debug!(request = ?frame);
|
||||
|
||||
// Write the frame to the socket
|
||||
self.connection.write_frame(&frame).await?;
|
||||
|
||||
// Read the response
|
||||
match self.read_response().await? {
|
||||
Frame::Integer(response) => Ok(response),
|
||||
frame => Err(frame.to_error()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Subscribes the client to the specified channels.
|
||||
///
|
||||
/// Once a client issues a subscribe command, it may no longer issue any
|
||||
/// non-pub/sub commands. The function consumes `self` and returns a `Subscriber`.
|
||||
///
|
||||
/// The `Subscriber` value is used to receive messages as well as manage the
|
||||
/// list of channels the client is subscribed to.
|
||||
#[instrument(skip(self))]
|
||||
pub async fn subscribe(mut self, channels: Vec<String>) -> crate::Result<Subscriber> {
|
||||
// Issue the subscribe command to the server and wait for confirmation.
|
||||
// The client will then have been transitioned into the "subscriber"
|
||||
// state and may only issue pub/sub commands from that point on.
|
||||
self.subscribe_cmd(&channels).await?;
|
||||
|
||||
// Return the `Subscriber` type
|
||||
Ok(Subscriber {
|
||||
client: self,
|
||||
subscribed_channels: channels,
|
||||
})
|
||||
}
|
||||
|
||||
/// The core `SUBSCRIBE` logic, used by misc subscribe fns
|
||||
async fn subscribe_cmd(&mut self, channels: &[String]) -> crate::Result<()> {
|
||||
// Convert the `Subscribe` command into a frame
|
||||
let frame = Subscribe::new(&channels).into_frame();
|
||||
|
||||
debug!(request = ?frame);
|
||||
|
||||
// Write the frame to the socket
|
||||
self.connection.write_frame(&frame).await?;
|
||||
|
||||
// For each channel being subscribed to, the server responds with a
|
||||
// message confirming subscription to that channel.
|
||||
for channel in channels {
|
||||
// Read the response
|
||||
let response = self.read_response().await?;
|
||||
|
||||
// Verify it is confirmation of subscription.
|
||||
match response {
|
||||
Frame::Array(ref frame) => match frame.as_slice() {
|
||||
// The server responds with an array frame in the form of:
|
||||
//
|
||||
// ```
|
||||
// [ "subscribe", channel, num-subscribed ]
|
||||
// ```
|
||||
//
|
||||
// where channel is the name of the channel and
|
||||
// num-subscribed is the number of channels that the client
|
||||
// is currently subscribed to.
|
||||
[subscribe, schannel, ..]
|
||||
if *subscribe == "subscribe" && *schannel == channel => {}
|
||||
_ => return Err(response.to_error()),
|
||||
},
|
||||
frame => return Err(frame.to_error()),
|
||||
};
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Reads a response frame from the socket.
|
||||
///
|
||||
/// If an `Error` frame is received, it is converted to `Err`.
|
||||
async fn read_response(&mut self) -> crate::Result<Frame> {
|
||||
let response = self.connection.read_frame().await?;
|
||||
|
||||
debug!(?response);
|
||||
|
||||
match response {
|
||||
// Error frames are converted to `Err`
|
||||
Some(Frame::Error(msg)) => Err(msg.into()),
|
||||
Some(frame) => Ok(frame),
|
||||
None => {
|
||||
// Receiving `None` here indicates the server has closed the
|
||||
// connection without sending a frame. This is unexpected and is
|
||||
// represented as a "connection reset by peer" error.
|
||||
let err = Error::new(ErrorKind::ConnectionReset, "connection reset by server");
|
||||
|
||||
Err(err.into())
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl Subscriber {
|
||||
/// Returns the set of channels currently subscribed to.
|
||||
pub fn get_subscribed(&self) -> &[String] {
|
||||
&self.subscribed_channels
|
||||
}
|
||||
|
||||
/// Receive the next message published on a subscribed channel, waiting if
|
||||
/// necessary.
|
||||
///
|
||||
/// `None` indicates the subscription has been terminated.
|
||||
pub async fn next_message(&mut self) -> crate::Result<Option<Message>> {
|
||||
match self.client.connection.read_frame().await? {
|
||||
Some(mframe) => {
|
||||
debug!(?mframe);
|
||||
|
||||
match mframe {
|
||||
Frame::Array(ref frame) => match frame.as_slice() {
|
||||
[message, channel, content] if *message == "message" => Ok(Some(Message {
|
||||
channel: channel.to_string(),
|
||||
content: Bytes::from(content.to_string()),
|
||||
})),
|
||||
_ => Err(mframe.to_error()),
|
||||
},
|
||||
frame => Err(frame.to_error()),
|
||||
}
|
||||
}
|
||||
None => Ok(None),
|
||||
}
|
||||
}
|
||||
|
||||
/// Convert the subscriber into a `Stream` yielding new messages published
|
||||
/// on subscribed channels.
|
||||
///
|
||||
/// `Subscriber` does not implement stream itself as doing so with safe code
|
||||
/// is non trivial. The usage of async/await would require a manual Stream
|
||||
/// implementation to use `unsafe` code. Instead, a conversion function is
|
||||
/// provided and the returned stream is implemented with the help of the
|
||||
/// `async-stream` crate.
|
||||
pub fn into_stream(mut self) -> impl Stream<Item = crate::Result<Message>> {
|
||||
// Uses the `try_stream` macro from the `async-stream` crate. Generators
|
||||
// are not stable in Rust. The crate uses a macro to simulate generators
|
||||
// on top of async/await. There are limitations, so read the
|
||||
// documentation there.
|
||||
try_stream! {
|
||||
while let Some(message) = self.next_message().await? {
|
||||
yield message;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Subscribe to a list of new channels
|
||||
#[instrument(skip(self))]
|
||||
pub async fn subscribe(&mut self, channels: &[String]) -> crate::Result<()> {
|
||||
// Issue the subscribe command
|
||||
self.client.subscribe_cmd(channels).await?;
|
||||
|
||||
// Update the set of subscribed channels.
|
||||
self.subscribed_channels
|
||||
.extend(channels.iter().map(Clone::clone));
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Unsubscribe to a list of new channels
|
||||
#[instrument(skip(self))]
|
||||
pub async fn unsubscribe(&mut self, channels: &[String]) -> crate::Result<()> {
|
||||
let frame = Unsubscribe::new(&channels).into_frame();
|
||||
|
||||
debug!(request = ?frame);
|
||||
|
||||
// Write the frame to the socket
|
||||
self.client.connection.write_frame(&frame).await?;
|
||||
|
||||
// if the input channel list is empty, server acknowledges as unsubscribing
|
||||
// from all subscribed channels, so we assert that the unsubscribe list received
|
||||
// matches the client subscribed one
|
||||
let num = if channels.is_empty() {
|
||||
self.subscribed_channels.len()
|
||||
} else {
|
||||
channels.len()
|
||||
};
|
||||
|
||||
// Read the response
|
||||
for _ in 0..num {
|
||||
let response = self.client.read_response().await?;
|
||||
|
||||
match response {
|
||||
Frame::Array(ref frame) => match frame.as_slice() {
|
||||
[unsubscribe, channel, ..] if *unsubscribe == "unsubscribe" => {
|
||||
let len = self.subscribed_channels.len();
|
||||
|
||||
if len == 0 {
|
||||
// There must be at least one channel
|
||||
return Err(response.to_error());
|
||||
}
|
||||
|
||||
// unsubscribed channel should exist in the subscribed list at this point
|
||||
self.subscribed_channels.retain(|c| *channel != &c[..]);
|
||||
|
||||
// Only a single channel should be removed from the
|
||||
// list of subscribed channels.
|
||||
if self.subscribed_channels.len() != len - 1 {
|
||||
return Err(response.to_error());
|
||||
}
|
||||
}
|
||||
_ => return Err(response.to_error()),
|
||||
},
|
||||
frame => return Err(frame.to_error()),
|
||||
};
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,93 @@
|
|||
use crate::{Connection, Db, Frame, Parse};
|
||||
|
||||
use bytes::Bytes;
|
||||
use tracing::{debug, instrument};
|
||||
|
||||
/// Get the value of key.
|
||||
///
|
||||
/// If the key does not exist the special value nil is returned. An error is
|
||||
/// returned if the value stored at key is not a string, because GET only
|
||||
/// handles string values.
|
||||
#[derive(Debug)]
|
||||
pub struct Get {
|
||||
/// Name of the key to get
|
||||
key: String,
|
||||
}
|
||||
|
||||
impl Get {
|
||||
/// Create a new `Get` command which fetches `key`.
|
||||
pub fn new(key: impl ToString) -> Get {
|
||||
Get {
|
||||
key: key.to_string(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Get the key
|
||||
pub fn key(&self) -> &str {
|
||||
&self.key
|
||||
}
|
||||
|
||||
/// Parse a `Get` instance from a received frame.
|
||||
///
|
||||
/// The `Parse` argument provides a cursor-like API to read fields from the
|
||||
/// `Frame`. At this point, the entire frame has already been received from
|
||||
/// the socket.
|
||||
///
|
||||
/// The `GET` string has already been consumed.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// Returns the `Get` value on success. If the frame is malformed, `Err` is
|
||||
/// returned.
|
||||
///
|
||||
/// # Format
|
||||
///
|
||||
/// Expects an array frame containing two entries.
|
||||
///
|
||||
/// ```text
|
||||
/// GET key
|
||||
/// ```
|
||||
pub(crate) fn parse_frames(parse: &mut Parse) -> crate::Result<Get> {
|
||||
// The `GET` string has already been consumed. The next value is the
|
||||
// name of the key to get. If the next value is not a string or the
|
||||
// input is fully consumed, then an error is returned.
|
||||
let key = parse.next_string()?;
|
||||
|
||||
Ok(Get { key })
|
||||
}
|
||||
|
||||
/// Apply the `Get` command to the specified `Db` instance.
|
||||
///
|
||||
/// The response is written to `dst`. This is called by the server in order
|
||||
/// to execute a received command.
|
||||
#[instrument(skip(self, db, dst))]
|
||||
pub(crate) async fn apply(self, db: &Db, dst: &mut Connection) -> crate::Result<()> {
|
||||
// Get the value from the shared database state
|
||||
let response = if let Some(value) = db.get(&self.key) {
|
||||
// If a value is present, it is written to the client in "bulk"
|
||||
// format.
|
||||
Frame::Bulk(value)
|
||||
} else {
|
||||
// If there is no value, `Null` is written.
|
||||
Frame::Null
|
||||
};
|
||||
|
||||
debug!(?response);
|
||||
|
||||
// Write the response back to the client
|
||||
dst.write_frame(&response).await?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Converts the command into an equivalent `Frame`.
|
||||
///
|
||||
/// This is called by the client when encoding a `Get` command to send to
|
||||
/// the server.
|
||||
pub(crate) fn into_frame(self) -> Frame {
|
||||
let mut frame = Frame::array();
|
||||
frame.push_bulk(Bytes::from("get".as_bytes()));
|
||||
frame.push_bulk(Bytes::from(self.key.into_bytes()));
|
||||
frame
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,116 @@
|
|||
mod get;
|
||||
pub use get::Get;
|
||||
|
||||
mod publish;
|
||||
pub use publish::Publish;
|
||||
|
||||
mod set;
|
||||
pub use set::Set;
|
||||
|
||||
mod subscribe;
|
||||
pub use subscribe::{Subscribe, Unsubscribe};
|
||||
|
||||
mod unknown;
|
||||
pub use unknown::Unknown;
|
||||
|
||||
use crate::{Connection, Db, Frame, Parse, ParseError, Shutdown};
|
||||
|
||||
/// Enumeration of supported Redis commands.
|
||||
///
|
||||
/// Methods called on `Command` are delegated to the command implementation.
|
||||
#[derive(Debug)]
|
||||
pub enum Command {
|
||||
Get(Get),
|
||||
Publish(Publish),
|
||||
Set(Set),
|
||||
Subscribe(Subscribe),
|
||||
Unsubscribe(Unsubscribe),
|
||||
Unknown(Unknown),
|
||||
}
|
||||
|
||||
impl Command {
|
||||
/// Parse a command from a received frame.
|
||||
///
|
||||
/// The `Frame` must represent a Redis command supported by `mini-redis` and
|
||||
/// be the array variant.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// On success, the command value is returned, otherwise, `Err` is returned.
|
||||
pub fn from_frame(frame: Frame) -> crate::Result<Command> {
|
||||
// The frame value is decorated with `Parse`. `Parse` provides a
|
||||
// "cursor" like API which makes parsing the command easier.
|
||||
//
|
||||
// The frame value must be an array variant. Any other frame variants
|
||||
// result in an error being returned.
|
||||
let mut parse = Parse::new(frame)?;
|
||||
|
||||
// All redis commands begin with the command name as a string. The name
|
||||
// is read and converted to lower cases in order to do case sensitive
|
||||
// matching.
|
||||
let command_name = parse.next_string()?.to_lowercase();
|
||||
|
||||
// Match the command name, delegating the rest of the parsing to the
|
||||
// specific command.
|
||||
let command = match &command_name[..] {
|
||||
"get" => Command::Get(Get::parse_frames(&mut parse)?),
|
||||
"publish" => Command::Publish(Publish::parse_frames(&mut parse)?),
|
||||
"set" => Command::Set(Set::parse_frames(&mut parse)?),
|
||||
"subscribe" => Command::Subscribe(Subscribe::parse_frames(&mut parse)?),
|
||||
"unsubscribe" => Command::Unsubscribe(Unsubscribe::parse_frames(&mut parse)?),
|
||||
_ => {
|
||||
// The command is not recognized and an Unknown command is
|
||||
// returned.
|
||||
//
|
||||
// `return` is called here to skip the `finish()` call below. As
|
||||
// the command is not recognized, there is most likely
|
||||
// unconsumed fields remaining in the `Parse` instance.
|
||||
return Ok(Command::Unknown(Unknown::new(command_name)));
|
||||
}
|
||||
};
|
||||
|
||||
// Check if there is any remaining unconsumed fields in the `Parse`
|
||||
// value. If fields remain, this indicates an unexpected frame format
|
||||
// and an error is returned.
|
||||
parse.finish()?;
|
||||
|
||||
// The command has been successfully parsed
|
||||
Ok(command)
|
||||
}
|
||||
|
||||
/// Apply the command to the specified `Db` instance.
|
||||
///
|
||||
/// The response is written to `dst`. This is called by the server in order
|
||||
/// to execute a received command.
|
||||
pub(crate) async fn apply(
|
||||
self,
|
||||
db: &Db,
|
||||
dst: &mut Connection,
|
||||
shutdown: &mut Shutdown,
|
||||
) -> crate::Result<()> {
|
||||
use Command::*;
|
||||
|
||||
match self {
|
||||
Get(cmd) => cmd.apply(db, dst).await,
|
||||
Publish(cmd) => cmd.apply(db, dst).await,
|
||||
Set(cmd) => cmd.apply(db, dst).await,
|
||||
Subscribe(cmd) => cmd.apply(db, dst, shutdown).await,
|
||||
Unknown(cmd) => cmd.apply(dst).await,
|
||||
// `Unsubscribe` cannot be applied. It may only be received from the
|
||||
// context of a `Subscribe` command.
|
||||
Unsubscribe(_) => Err("`Unsubscribe` is unsupported in this context".into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns the command name
|
||||
pub(crate) fn get_name(&self) -> &str {
|
||||
match self {
|
||||
Command::Get(_) => "get",
|
||||
Command::Publish(_) => "pub",
|
||||
Command::Set(_) => "set",
|
||||
Command::Subscribe(_) => "subscribe",
|
||||
Command::Unsubscribe(_) => "unsubscribe",
|
||||
Command::Unknown(cmd) => cmd.get_name(),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,101 @@
|
|||
use crate::{Connection, Db, Frame, Parse};
|
||||
|
||||
use bytes::Bytes;
|
||||
|
||||
/// Posts a message to the given channel.
|
||||
///
|
||||
/// Send a message into a channel without any knowledge of individual consumers.
|
||||
/// Consumers may subscribe to channels in order to receive the messages.
|
||||
///
|
||||
/// Channel names have no relation to the key-value namespace. Publishing on a
|
||||
/// channel named "foo" has no relation to setting the "foo" key.
|
||||
#[derive(Debug)]
|
||||
pub struct Publish {
|
||||
/// Name of the channel on which the message should be published.
|
||||
channel: String,
|
||||
|
||||
/// The message to publish.
|
||||
message: Bytes,
|
||||
}
|
||||
|
||||
impl Publish {
|
||||
/// Create a new `Publish` command which sends `message` on `channel`.
|
||||
pub(crate) fn new(channel: impl ToString, message: Bytes) -> Publish {
|
||||
Publish {
|
||||
channel: channel.to_string(),
|
||||
message,
|
||||
}
|
||||
}
|
||||
|
||||
/// Parse a `Publish` instance from a received frame.
|
||||
///
|
||||
/// The `Parse` argument provides a cursor-like API to read fields from the
|
||||
/// `Frame`. At this point, the entire frame has already been received from
|
||||
/// the socket.
|
||||
///
|
||||
/// The `PUBLISH` string has already been consumed.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// On success, the `Publish` value is returned. If the frame is malformed,
|
||||
/// `Err` is returned.
|
||||
///
|
||||
/// # Format
|
||||
///
|
||||
/// Expects an array frame containing three entries.
|
||||
///
|
||||
/// ```text
|
||||
/// PUBLISH channel message
|
||||
/// ```
|
||||
pub(crate) fn parse_frames(parse: &mut Parse) -> crate::Result<Publish> {
|
||||
// The `PUBLISH` string has already been consumed. Extract the `channel`
|
||||
// and `message` values from the frame.
|
||||
//
|
||||
// The `channel` must be a valid string.
|
||||
let channel = parse.next_string()?;
|
||||
|
||||
// The `message` is arbitrary bytes.
|
||||
let message = parse.next_bytes()?;
|
||||
|
||||
Ok(Publish { channel, message })
|
||||
}
|
||||
|
||||
/// Apply the `Publish` command to the specified `Db` instance.
|
||||
///
|
||||
/// The response is written to `dst`. This is called by the server in order
|
||||
/// to execute a received command.
|
||||
pub(crate) async fn apply(self, db: &Db, dst: &mut Connection) -> crate::Result<()> {
|
||||
// The shared state contains the `tokio::sync::broadcast::Sender` for
|
||||
// all active channels. Calling `db.publish` dispatches the message into
|
||||
// the appropriate channel.
|
||||
//
|
||||
// The number of subscribers currently listening on the channel is
|
||||
// returned. This does not mean that `num_subscriber` channels will
|
||||
// receive the message. Subscribers may drop before receiving the
|
||||
// message. Given this, `num_subscribers` should only be used as a
|
||||
// "hint".
|
||||
let num_subscribers = db.publish(&self.channel, self.message);
|
||||
|
||||
// The number of subscribers is returned as the response to the publish
|
||||
// request.
|
||||
let response = Frame::Integer(num_subscribers as u64);
|
||||
|
||||
// Write the frame to the client.
|
||||
dst.write_frame(&response).await?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Converts the command into an equivalent `Frame`.
|
||||
///
|
||||
/// This is called by the client when encoding a `Publish` command to send
|
||||
/// to the server.
|
||||
pub(crate) fn into_frame(self) -> Frame {
|
||||
let mut frame = Frame::array();
|
||||
frame.push_bulk(Bytes::from("publish".as_bytes()));
|
||||
frame.push_bulk(Bytes::from(self.channel.into_bytes()));
|
||||
frame.push_bulk(self.message);
|
||||
|
||||
frame
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,161 @@
|
|||
use crate::cmd::{Parse, ParseError};
|
||||
use crate::{Connection, Db, Frame};
|
||||
|
||||
use bytes::Bytes;
|
||||
use std::time::Duration;
|
||||
use tracing::{debug, instrument};
|
||||
|
||||
/// Set `key` to hold the string `value`.
|
||||
///
|
||||
/// If `key` already holds a value, it is overwritten, regardless of its type.
|
||||
/// Any previous time to live associated with the key is discarded on successful
|
||||
/// SET operation.
|
||||
///
|
||||
/// # Options
|
||||
///
|
||||
/// Currently, the following options are supported:
|
||||
///
|
||||
/// * EX `seconds` -- Set the specified expire time, in seconds.
|
||||
/// * PX `milliseconds` -- Set the specified expire time, in milliseconds.
|
||||
#[derive(Debug)]
|
||||
pub struct Set {
|
||||
/// the lookup key
|
||||
key: String,
|
||||
|
||||
/// the value to be stored
|
||||
value: Bytes,
|
||||
|
||||
/// When to expire the key
|
||||
expire: Option<Duration>,
|
||||
}
|
||||
|
||||
impl Set {
|
||||
/// Create a new `Set` command which sets `key` to `value`.
|
||||
///
|
||||
/// If `expire` is `Some`, the value should expire after the specified
|
||||
/// duration.
|
||||
pub fn new(key: impl ToString, value: Bytes, expire: Option<Duration>) -> Set {
|
||||
Set {
|
||||
key: key.to_string(),
|
||||
value,
|
||||
expire,
|
||||
}
|
||||
}
|
||||
|
||||
/// Get the key
|
||||
pub fn key(&self) -> &str {
|
||||
&self.key
|
||||
}
|
||||
|
||||
/// Get the value
|
||||
pub fn value(&self) -> &Bytes {
|
||||
&self.value
|
||||
}
|
||||
|
||||
/// Get the expire
|
||||
pub fn expire(&self) -> Option<Duration> {
|
||||
self.expire
|
||||
}
|
||||
|
||||
/// Parse a `Set` instance from a received frame.
|
||||
///
|
||||
/// The `Parse` argument provides a cursor-like API to read fields from the
|
||||
/// `Frame`. At this point, the entire frame has already been received from
|
||||
/// the socket.
|
||||
///
|
||||
/// The `SET` string has already been consumed.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// Returns the `Set` value on success. If the frame is malformed, `Err` is
|
||||
/// returned.
|
||||
///
|
||||
/// # Format
|
||||
///
|
||||
/// Expects an array frame containing at least 3 entries.
|
||||
///
|
||||
/// ```text
|
||||
/// SET key value [EX seconds|PX milliseconds]
|
||||
/// ```
|
||||
pub(crate) fn parse_frames(parse: &mut Parse) -> crate::Result<Set> {
|
||||
use ParseError::EndOfStream;
|
||||
|
||||
// Read the key to set. This is a required field
|
||||
let key = parse.next_string()?;
|
||||
|
||||
// Read the value to set. This is a required field.
|
||||
let value = parse.next_bytes()?;
|
||||
|
||||
// The expiration is optional. If nothing else follows, then it is
|
||||
// `None`.
|
||||
let mut expire = None;
|
||||
|
||||
// Attempt to parse another string.
|
||||
match parse.next_string() {
|
||||
Ok(s) if s.to_uppercase() == "EX" => {
|
||||
// An expiration is specified in seconds. The next value is an
|
||||
// integer.
|
||||
let secs = parse.next_int()?;
|
||||
expire = Some(Duration::from_secs(secs));
|
||||
}
|
||||
Ok(s) if s.to_uppercase() == "PX" => {
|
||||
// An expiration is specified in milliseconds. The next value is
|
||||
// an integer.
|
||||
let ms = parse.next_int()?;
|
||||
expire = Some(Duration::from_millis(ms));
|
||||
}
|
||||
// Currently, mini-redis does not support any of the other SET
|
||||
// options. An error here results in the connection being
|
||||
// terminated. Other connections will continue to operate normally.
|
||||
Ok(_) => return Err("currently `SET` only supports the expiration option".into()),
|
||||
// The `EndOfStream` error indicates there is no further data to
|
||||
// parse. In this case, it is a normal run time situation and
|
||||
// indicates there are no specified `SET` options.
|
||||
Err(EndOfStream) => {}
|
||||
// All other errors are bubbled up, resulting in the connection
|
||||
// being terminated.
|
||||
Err(err) => return Err(err.into()),
|
||||
}
|
||||
|
||||
Ok(Set { key, value, expire })
|
||||
}
|
||||
|
||||
/// Apply the `Set` command to the specified `Db` instance.
|
||||
///
|
||||
/// The response is written to `dst`. This is called by the server in order
|
||||
/// to execute a received command.
|
||||
#[instrument(skip(self, db, dst))]
|
||||
pub(crate) async fn apply(self, db: &Db, dst: &mut Connection) -> crate::Result<()> {
|
||||
// Set the value in the shared database state.
|
||||
db.set(self.key, self.value, self.expire);
|
||||
|
||||
// Create a success response and write it to `dst`.
|
||||
let response = Frame::Simple("OK".to_string());
|
||||
debug!(?response);
|
||||
dst.write_frame(&response).await?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Converts the command into an equivalent `Frame`.
|
||||
///
|
||||
/// This is called by the client when encoding a `Set` command to send to
|
||||
/// the server.
|
||||
pub(crate) fn into_frame(self) -> Frame {
|
||||
let mut frame = Frame::array();
|
||||
frame.push_bulk(Bytes::from("set".as_bytes()));
|
||||
frame.push_bulk(Bytes::from(self.key.into_bytes()));
|
||||
frame.push_bulk(self.value);
|
||||
if let Some(ms) = self.expire {
|
||||
// Expirations in Redis procotol can be specified in two ways
|
||||
// 1. SET key value EX seconds
|
||||
// 2. SET key value PX milliseconds
|
||||
// We the second option because it allows greater precision and
|
||||
// src/bin/cli.rs parses the expiration argument as milliseconds
|
||||
// in duration_from_ms_str()
|
||||
frame.push_bulk(Bytes::from("px".as_bytes()));
|
||||
frame.push_int(ms.as_millis() as u64);
|
||||
}
|
||||
frame
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,351 @@
|
|||
use crate::cmd::{Parse, ParseError, Unknown};
|
||||
use crate::{Command, Connection, Db, Frame, Shutdown};
|
||||
|
||||
use bytes::Bytes;
|
||||
use std::pin::Pin;
|
||||
use tokio::select;
|
||||
use tokio::sync::broadcast;
|
||||
use tokio_stream::{Stream, StreamExt, StreamMap};
|
||||
|
||||
/// Subscribes the client to one or more channels.
|
||||
///
|
||||
/// Once the client enters the subscribed state, it is not supposed to issue any
|
||||
/// other commands, except for additional SUBSCRIBE, PSUBSCRIBE, UNSUBSCRIBE,
|
||||
/// PUNSUBSCRIBE, PING and QUIT commands.
|
||||
#[derive(Debug)]
|
||||
pub struct Subscribe {
|
||||
channels: Vec<String>,
|
||||
}
|
||||
|
||||
/// Unsubscribes the client from one or more channels.
|
||||
///
|
||||
/// When no channels are specified, the client is unsubscribed from all the
|
||||
/// previously subscribed channels.
|
||||
#[derive(Clone, Debug)]
|
||||
pub struct Unsubscribe {
|
||||
channels: Vec<String>,
|
||||
}
|
||||
|
||||
/// Stream of messages. The stream receives messages from the
|
||||
/// `broadcast::Receiver`. We use `stream!` to create a `Stream` that consumes
|
||||
/// messages. Because `stream!` values cannot be named, we box the stream using
|
||||
/// a trait object.
|
||||
type Messages = Pin<Box<dyn Stream<Item = Bytes> + Send>>;
|
||||
|
||||
impl Subscribe {
|
||||
/// Creates a new `Subscribe` command to listen on the specified channels.
|
||||
pub(crate) fn new(channels: &[String]) -> Subscribe {
|
||||
Subscribe {
|
||||
channels: channels.to_vec(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Parse a `Subscribe` instance from a received frame.
|
||||
///
|
||||
/// The `Parse` argument provides a cursor-like API to read fields from the
|
||||
/// `Frame`. At this point, the entire frame has already been received from
|
||||
/// the socket.
|
||||
///
|
||||
/// The `SUBSCRIBE` string has already been consumed.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// On success, the `Subscribe` value is returned. If the frame is
|
||||
/// malformed, `Err` is returned.
|
||||
///
|
||||
/// # Format
|
||||
///
|
||||
/// Expects an array frame containing two or more entries.
|
||||
///
|
||||
/// ```text
|
||||
/// SUBSCRIBE channel [channel ...]
|
||||
/// ```
|
||||
pub(crate) fn parse_frames(parse: &mut Parse) -> crate::Result<Subscribe> {
|
||||
use ParseError::EndOfStream;
|
||||
|
||||
// The `SUBSCRIBE` string has already been consumed. At this point,
|
||||
// there is one or more strings remaining in `parse`. These represent
|
||||
// the channels to subscribe to.
|
||||
//
|
||||
// Extract the first string. If there is none, the the frame is
|
||||
// malformed and the error is bubbled up.
|
||||
let mut channels = vec![parse.next_string()?];
|
||||
|
||||
// Now, the remainder of the frame is consumed. Each value must be a
|
||||
// string or the frame is malformed. Once all values in the frame have
|
||||
// been consumed, the command is fully parsed.
|
||||
loop {
|
||||
match parse.next_string() {
|
||||
// A string has been consumed from the `parse`, push it into the
|
||||
// list of channels to subscribe to.
|
||||
Ok(s) => channels.push(s),
|
||||
// The `EndOfStream` error indicates there is no further data to
|
||||
// parse.
|
||||
Err(EndOfStream) => break,
|
||||
// All other errors are bubbled up, resulting in the connection
|
||||
// being terminated.
|
||||
Err(err) => return Err(err.into()),
|
||||
}
|
||||
}
|
||||
|
||||
Ok(Subscribe { channels })
|
||||
}
|
||||
|
||||
/// Apply the `Subscribe` command to the specified `Db` instance.
|
||||
///
|
||||
/// This function is the entry point and includes the initial list of
|
||||
/// channels to subscribe to. Additional `subscribe` and `unsubscribe`
|
||||
/// commands may be received from the client and the list of subscriptions
|
||||
/// are updated accordingly.
|
||||
///
|
||||
/// [here]: https://redis.io/topics/pubsub
|
||||
pub(crate) async fn apply(
|
||||
mut self,
|
||||
db: &Db,
|
||||
dst: &mut Connection,
|
||||
shutdown: &mut Shutdown,
|
||||
) -> crate::Result<()> {
|
||||
// Each individual channel subscription is handled using a
|
||||
// `sync::broadcast` channel. Messages are then fanned out to all
|
||||
// clients currently subscribed to the channels.
|
||||
//
|
||||
// An individual client may subscribe to multiple channels and may
|
||||
// dynamically add and remove channels from its subscription set. To
|
||||
// handle this, a `StreamMap` is used to track active subscriptions. The
|
||||
// `StreamMap` merges messages from individual broadcast channels as
|
||||
// they are received.
|
||||
let mut subscriptions = StreamMap::new();
|
||||
|
||||
loop {
|
||||
// `self.channels` is used to track additional channels to subscribe
|
||||
// to. When new `SUBSCRIBE` commands are received during the
|
||||
// execution of `apply`, the new channels are pushed onto this vec.
|
||||
for channel_name in self.channels.drain(..) {
|
||||
subscribe_to_channel(channel_name, &mut subscriptions, db, dst).await?;
|
||||
}
|
||||
|
||||
// Wait for one of the following to happen:
|
||||
//
|
||||
// - Receive a message from one of the subscribed channels.
|
||||
// - Receive a subscribe or unsubscribe command from the client.
|
||||
// - A server shutdown signal.
|
||||
select! {
|
||||
// Receive messages from subscribed channels
|
||||
Some((channel_name, msg)) = subscriptions.next() => {
|
||||
dst.write_frame(&make_message_frame(channel_name, msg)).await?;
|
||||
},
|
||||
res = dst.read_frame() => {
|
||||
let frame = match res? {
|
||||
Some(frame) => frame,
|
||||
// This happens if the remote client has disconnected.
|
||||
None => return Ok(())
|
||||
};
|
||||
|
||||
handle_command(
|
||||
frame,
|
||||
&mut self.channels,
|
||||
&mut subscriptions,
|
||||
dst,
|
||||
).await?;
|
||||
},
|
||||
_ = shutdown.recv() => {
|
||||
return Ok(());
|
||||
}
|
||||
};
|
||||
}
|
||||
}
|
||||
|
||||
/// Converts the command into an equivalent `Frame`.
|
||||
///
|
||||
/// This is called by the client when encoding a `Subscribe` command to send
|
||||
/// to the server.
|
||||
pub(crate) fn into_frame(self) -> Frame {
|
||||
let mut frame = Frame::array();
|
||||
frame.push_bulk(Bytes::from("subscribe".as_bytes()));
|
||||
for channel in self.channels {
|
||||
frame.push_bulk(Bytes::from(channel.into_bytes()));
|
||||
}
|
||||
frame
|
||||
}
|
||||
}
|
||||
|
||||
async fn subscribe_to_channel(
|
||||
channel_name: String,
|
||||
subscriptions: &mut StreamMap<String, Messages>,
|
||||
db: &Db,
|
||||
dst: &mut Connection,
|
||||
) -> crate::Result<()> {
|
||||
let mut rx = db.subscribe(channel_name.clone());
|
||||
|
||||
// Subscribe to the channel.
|
||||
let rx = Box::pin(async_stream::stream! {
|
||||
loop {
|
||||
match rx.recv().await {
|
||||
Ok(msg) => yield msg,
|
||||
// If we lagged in consuming messages, just resume.
|
||||
Err(broadcast::error::RecvError::Lagged(_)) => {}
|
||||
Err(_) => break,
|
||||
}
|
||||
}
|
||||
});
|
||||
|
||||
// Track subscription in this client's subscription set.
|
||||
subscriptions.insert(channel_name.clone(), rx);
|
||||
|
||||
// Respond with the successful subscription
|
||||
let response = make_subscribe_frame(channel_name, subscriptions.len());
|
||||
dst.write_frame(&response).await?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Handle a command received while inside `Subscribe::apply`. Only subscribe
|
||||
/// and unsubscribe commands are permitted in this context.
|
||||
///
|
||||
/// Any new subscriptions are appended to `subscribe_to` instead of modifying
|
||||
/// `subscriptions`.
|
||||
async fn handle_command(
|
||||
frame: Frame,
|
||||
subscribe_to: &mut Vec<String>,
|
||||
subscriptions: &mut StreamMap<String, Messages>,
|
||||
dst: &mut Connection,
|
||||
) -> crate::Result<()> {
|
||||
// A command has been received from the client.
|
||||
//
|
||||
// Only `SUBSCRIBE` and `UNSUBSCRIBE` commands are permitted
|
||||
// in this context.
|
||||
match Command::from_frame(frame)? {
|
||||
Command::Subscribe(subscribe) => {
|
||||
// The `apply` method will subscribe to the channels we add to this
|
||||
// vector.
|
||||
subscribe_to.extend(subscribe.channels.into_iter());
|
||||
}
|
||||
Command::Unsubscribe(mut unsubscribe) => {
|
||||
// If no channels are specified, this requests unsubscribing from
|
||||
// **all** channels. To implement this, the `unsubscribe.channels`
|
||||
// vec is populated with the list of channels currently subscribed
|
||||
// to.
|
||||
if unsubscribe.channels.is_empty() {
|
||||
unsubscribe.channels = subscriptions
|
||||
.keys()
|
||||
.map(|channel_name| channel_name.to_string())
|
||||
.collect();
|
||||
}
|
||||
|
||||
for channel_name in unsubscribe.channels {
|
||||
subscriptions.remove(&channel_name);
|
||||
|
||||
let response = make_unsubscribe_frame(channel_name, subscriptions.len());
|
||||
dst.write_frame(&response).await?;
|
||||
}
|
||||
}
|
||||
command => {
|
||||
let cmd = Unknown::new(command.get_name());
|
||||
cmd.apply(dst).await?;
|
||||
}
|
||||
}
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Creates the response to a subcribe request.
|
||||
///
|
||||
/// All of these functions take the `channel_name` as a `String` instead of
|
||||
/// a `&str` since `Bytes::from` can reuse the allocation in the `String`, and
|
||||
/// taking a `&str` would require copying the data. This allows the caller to
|
||||
/// decide whether to clone the channel name or not.
|
||||
fn make_subscribe_frame(channel_name: String, num_subs: usize) -> Frame {
|
||||
let mut response = Frame::array();
|
||||
response.push_bulk(Bytes::from_static(b"subscribe"));
|
||||
response.push_bulk(Bytes::from(channel_name));
|
||||
response.push_int(num_subs as u64);
|
||||
response
|
||||
}
|
||||
|
||||
/// Creates the response to an unsubcribe request.
|
||||
fn make_unsubscribe_frame(channel_name: String, num_subs: usize) -> Frame {
|
||||
let mut response = Frame::array();
|
||||
response.push_bulk(Bytes::from_static(b"unsubscribe"));
|
||||
response.push_bulk(Bytes::from(channel_name));
|
||||
response.push_int(num_subs as u64);
|
||||
response
|
||||
}
|
||||
|
||||
/// Creates a message informing the client about a new message on a channel that
|
||||
/// the client subscribes to.
|
||||
fn make_message_frame(channel_name: String, msg: Bytes) -> Frame {
|
||||
let mut response = Frame::array();
|
||||
response.push_bulk(Bytes::from_static(b"message"));
|
||||
response.push_bulk(Bytes::from(channel_name));
|
||||
response.push_bulk(msg);
|
||||
response
|
||||
}
|
||||
|
||||
impl Unsubscribe {
|
||||
/// Create a new `Unsubscribe` command with the given `channels`.
|
||||
pub(crate) fn new(channels: &[String]) -> Unsubscribe {
|
||||
Unsubscribe {
|
||||
channels: channels.to_vec(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Parse a `Unsubscribe` instance from a received frame.
|
||||
///
|
||||
/// The `Parse` argument provides a cursor-like API to read fields from the
|
||||
/// `Frame`. At this point, the entire frame has already been received from
|
||||
/// the socket.
|
||||
///
|
||||
/// The `UNSUBSCRIBE` string has already been consumed.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// On success, the `Unsubscribe` value is returned. If the frame is
|
||||
/// malformed, `Err` is returned.
|
||||
///
|
||||
/// # Format
|
||||
///
|
||||
/// Expects an array frame containing at least one entry.
|
||||
///
|
||||
/// ```text
|
||||
/// UNSUBSCRIBE [channel [channel ...]]
|
||||
/// ```
|
||||
pub(crate) fn parse_frames(parse: &mut Parse) -> Result<Unsubscribe, ParseError> {
|
||||
use ParseError::EndOfStream;
|
||||
|
||||
// There may be no channels listed, so start with an empty vec.
|
||||
let mut channels = vec![];
|
||||
|
||||
// Each entry in the frame must be a string or the frame is malformed.
|
||||
// Once all values in the frame have been consumed, the command is fully
|
||||
// parsed.
|
||||
loop {
|
||||
match parse.next_string() {
|
||||
// A string has been consumed from the `parse`, push it into the
|
||||
// list of channels to unsubscribe from.
|
||||
Ok(s) => channels.push(s),
|
||||
// The `EndOfStream` error indicates there is no further data to
|
||||
// parse.
|
||||
Err(EndOfStream) => break,
|
||||
// All other errors are bubbled up, resulting in the connection
|
||||
// being terminated.
|
||||
Err(err) => return Err(err),
|
||||
}
|
||||
}
|
||||
|
||||
Ok(Unsubscribe { channels })
|
||||
}
|
||||
|
||||
/// Converts the command into an equivalent `Frame`.
|
||||
///
|
||||
/// This is called by the client when encoding an `Unsubscribe` command to
|
||||
/// send to the server.
|
||||
pub(crate) fn into_frame(self) -> Frame {
|
||||
let mut frame = Frame::array();
|
||||
frame.push_bulk(Bytes::from("unsubscribe".as_bytes()));
|
||||
|
||||
for channel in self.channels {
|
||||
frame.push_bulk(Bytes::from(channel.into_bytes()));
|
||||
}
|
||||
|
||||
frame
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,37 @@
|
|||
use crate::{Connection, Frame};
|
||||
|
||||
use tracing::{debug, instrument};
|
||||
|
||||
/// Represents an "unknown" command. This is not a real `Redis` command.
|
||||
#[derive(Debug)]
|
||||
pub struct Unknown {
|
||||
command_name: String,
|
||||
}
|
||||
|
||||
impl Unknown {
|
||||
/// Create a new `Unknown` command which responds to unknown commands
|
||||
/// issued by clients
|
||||
pub(crate) fn new(key: impl ToString) -> Unknown {
|
||||
Unknown {
|
||||
command_name: key.to_string(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns the command name
|
||||
pub(crate) fn get_name(&self) -> &str {
|
||||
&self.command_name
|
||||
}
|
||||
|
||||
/// Responds to the client, indicating the command is not recognized.
|
||||
///
|
||||
/// This usually means the command is not yet implemented by `mini-redis`.
|
||||
#[instrument(skip(self, dst))]
|
||||
pub(crate) async fn apply(self, dst: &mut Connection) -> crate::Result<()> {
|
||||
let response = Frame::Error(format!("ERR unknown command '{}'", self.command_name));
|
||||
|
||||
debug!(?response);
|
||||
|
||||
dst.write_frame(&response).await?;
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,237 @@
|
|||
use crate::frame::{self, Frame};
|
||||
|
||||
use bytes::{Buf, BytesMut};
|
||||
use std::io::{self, Cursor};
|
||||
use tokio::io::{AsyncReadExt, AsyncWriteExt, BufWriter};
|
||||
use tokio::net::TcpStream;
|
||||
|
||||
/// Send and receive `Frame` values from a remote peer.
|
||||
///
|
||||
/// When implementing networking protocols, a message on that protocol is
|
||||
/// often composed of several smaller messages known as frames. The purpose of
|
||||
/// `Connection` is to read and write frames on the underlying `TcpStream`.
|
||||
///
|
||||
/// To read frames, the `Connection` uses an internal buffer, which is filled
|
||||
/// up until there are enough bytes to create a full frame. Once this happens,
|
||||
/// the `Connection` creates the frame and returns it to the caller.
|
||||
///
|
||||
/// When sending frames, the frame is first encoded into the write buffer.
|
||||
/// The contents of the write buffer are then written to the socket.
|
||||
#[derive(Debug)]
|
||||
pub struct Connection {
|
||||
// The `TcpStream`. It is decorated with a `BufWriter`, which provides write
|
||||
// level buffering. The `BufWriter` implementation provided by Tokio is
|
||||
// sufficient for our needs.
|
||||
stream: BufWriter<TcpStream>,
|
||||
|
||||
// The buffer for reading frames.
|
||||
buffer: BytesMut,
|
||||
}
|
||||
|
||||
impl Connection {
|
||||
/// Create a new `Connection`, backed by `socket`. Read and write buffers
|
||||
/// are initialized.
|
||||
pub fn new(socket: TcpStream) -> Connection {
|
||||
Connection {
|
||||
stream: BufWriter::new(socket),
|
||||
// Default to a 4KB read buffer. For the use case of mini redis,
|
||||
// this is fine. However, real applications will want to tune this
|
||||
// value to their specific use case. There is a high likelihood that
|
||||
// a larger read buffer will work better.
|
||||
buffer: BytesMut::with_capacity(4 * 1024),
|
||||
}
|
||||
}
|
||||
|
||||
/// Read a single `Frame` value from the underlying stream.
|
||||
///
|
||||
/// The function waits until it has retrieved enough data to parse a frame.
|
||||
/// Any data remaining in the read buffer after the frame has been parsed is
|
||||
/// kept there for the next call to `read_frame`.
|
||||
///
|
||||
/// # Returns
|
||||
///
|
||||
/// On success, the received frame is returned. If the `TcpStream`
|
||||
/// is closed in a way that doesn't break a frame in half, it returns
|
||||
/// `None`. Otherwise, an error is returned.
|
||||
pub async fn read_frame(&mut self) -> crate::Result<Option<Frame>> {
|
||||
loop {
|
||||
// Attempt to parse a frame from the buffered data. If enough data
|
||||
// has been buffered, the frame is returned.
|
||||
if let Some(frame) = self.parse_frame()? {
|
||||
return Ok(Some(frame));
|
||||
}
|
||||
|
||||
// There is not enough buffered data to read a frame. Attempt to
|
||||
// read more data from the socket.
|
||||
//
|
||||
// On success, the number of bytes is returned. `0` indicates "end
|
||||
// of stream".
|
||||
if 0 == self.stream.read_buf(&mut self.buffer).await? {
|
||||
// The remote closed the connection. For this to be a clean
|
||||
// shutdown, there should be no data in the read buffer. If
|
||||
// there is, this means that the peer closed the socket while
|
||||
// sending a frame.
|
||||
if self.buffer.is_empty() {
|
||||
return Ok(None);
|
||||
} else {
|
||||
let s = "connection reset by peer".into();
|
||||
return Err(s);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Tries to parse a frame from the buffer. If the buffer contains enough
|
||||
/// data, the frame is returned and the data removed from the buffer. If not
|
||||
/// enough data has been buffered yet, `Ok(None)` is returned. If the
|
||||
/// buffered data does not represent a valid frame, `Err` is returned.
|
||||
fn parse_frame(&mut self) -> crate::Result<Option<Frame>> {
|
||||
use frame::Error::Incomplete;
|
||||
|
||||
// Cursor is used to track the "current" location in the
|
||||
// buffer. Cursor also implements `Buf` from the `bytes` crate
|
||||
// which provides a number of helpful utilities for working
|
||||
// with bytes.
|
||||
let mut buf = Cursor::new(&self.buffer[..]);
|
||||
|
||||
// The first step is to check if enough data has been buffered to parse
|
||||
// a single frame. This step is usually much faster than doing a full
|
||||
// parse of the frame, and allows us to skip allocating data structures
|
||||
// to hold the frame data unless we know the full frame has been
|
||||
// received.
|
||||
match Frame::check(&mut buf) {
|
||||
Ok(_) => {
|
||||
// The `check` function will have advanced the cursor until the
|
||||
// end of the frame. Since the cursor had position set to zero
|
||||
// before `Frame::check` was called, we obtain the length of the
|
||||
// frame by checking the cursor position.
|
||||
let len = buf.position() as usize;
|
||||
|
||||
// Reset the position to zero before passing the cursor to
|
||||
// `Frame::parse`.
|
||||
buf.set_position(0);
|
||||
|
||||
// Parse the frame from the buffer. This allocates the necessary
|
||||
// structures to represent the frame and returns the frame
|
||||
// value.
|
||||
//
|
||||
// If the encoded frame representation is invalid, an error is
|
||||
// returned. This should terminate the **current** connection
|
||||
// but should not impact any other connected client.
|
||||
let frame = Frame::parse(&mut buf)?;
|
||||
|
||||
// Discard the parsed data from the read buffer.
|
||||
//
|
||||
// When `advance` is called on the read buffer, all of the data
|
||||
// up to `len` is discarded. The details of how this works is
|
||||
// left to `BytesMut`. This is often done by moving an internal
|
||||
// cursor, but it may be done by reallocating and copying data.
|
||||
self.buffer.advance(len);
|
||||
|
||||
// Return the parsed frame to the caller.
|
||||
Ok(Some(frame))
|
||||
}
|
||||
// There is not enough data present in the read buffer to parse a
|
||||
// single frame. We must wait for more data to be received from the
|
||||
// socket. Reading from the socket will be done in the statement
|
||||
// after this `match`.
|
||||
//
|
||||
// We do not want to return `Err` from here as this "error" is an
|
||||
// expected runtime condition.
|
||||
Err(Incomplete) => Ok(None),
|
||||
// An error was encountered while parsing the frame. The connection
|
||||
// is now in an invalid state. Returning `Err` from here will result
|
||||
// in the connection being closed.
|
||||
Err(e) => Err(e.into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Write a single `Frame` value to the underlying stream.
|
||||
///
|
||||
/// The `Frame` value is written to the socket using the various `write_*`
|
||||
/// functions provided by `AsyncWrite`. Calling these functions directly on
|
||||
/// a `TcpStream` is **not** advised, as this will result in a large number of
|
||||
/// syscalls. However, it is fine to call these functions on a *buffered*
|
||||
/// write stream. The data will be written to the buffer. Once the buffer is
|
||||
/// full, it is flushed to the underlying socket.
|
||||
pub async fn write_frame(&mut self, frame: &Frame) -> io::Result<()> {
|
||||
// Arrays are encoded by encoding each entry. All other frame types are
|
||||
// considered literals. For now, mini-redis is not able to encode
|
||||
// recursive frame structures. See below for more details.
|
||||
match frame {
|
||||
Frame::Array(val) => {
|
||||
// Encode the frame type prefix. For an array, it is `*`.
|
||||
self.stream.write_u8(b'*').await?;
|
||||
|
||||
// Encode the length of the array.
|
||||
self.write_decimal(val.len() as u64).await?;
|
||||
|
||||
// Iterate and encode each entry in the array.
|
||||
for entry in &**val {
|
||||
self.write_value(entry).await?;
|
||||
}
|
||||
}
|
||||
// The frame type is a literal. Encode the value directly.
|
||||
_ => self.write_value(frame).await?,
|
||||
}
|
||||
|
||||
// Ensure the encoded frame is written to the socket. The calls above
|
||||
// are to the buffered stream and writes. Calling `flush` writes the
|
||||
// remaining contents of the buffer to the socket.
|
||||
self.stream.flush().await
|
||||
}
|
||||
|
||||
/// Write a frame literal to the stream
|
||||
async fn write_value(&mut self, frame: &Frame) -> io::Result<()> {
|
||||
match frame {
|
||||
Frame::Simple(val) => {
|
||||
self.stream.write_u8(b'+').await?;
|
||||
self.stream.write_all(val.as_bytes()).await?;
|
||||
self.stream.write_all(b"\r\n").await?;
|
||||
}
|
||||
Frame::Error(val) => {
|
||||
self.stream.write_u8(b'-').await?;
|
||||
self.stream.write_all(val.as_bytes()).await?;
|
||||
self.stream.write_all(b"\r\n").await?;
|
||||
}
|
||||
Frame::Integer(val) => {
|
||||
self.stream.write_u8(b':').await?;
|
||||
self.write_decimal(*val).await?;
|
||||
}
|
||||
Frame::Null => {
|
||||
self.stream.write_all(b"$-1\r\n").await?;
|
||||
}
|
||||
Frame::Bulk(val) => {
|
||||
let len = val.len();
|
||||
|
||||
self.stream.write_u8(b'$').await?;
|
||||
self.write_decimal(len as u64).await?;
|
||||
self.stream.write_all(val).await?;
|
||||
self.stream.write_all(b"\r\n").await?;
|
||||
}
|
||||
// Encoding an `Array` from within a value cannot be done using a
|
||||
// recursive strategy. In general, async fns do not support
|
||||
// recursion. Mini-redis has not needed to encode nested arrays yet,
|
||||
// so for now it is skipped.
|
||||
Frame::Array(_val) => unreachable!(),
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Write a decimal frame to the stream
|
||||
async fn write_decimal(&mut self, val: u64) -> io::Result<()> {
|
||||
use std::io::Write;
|
||||
|
||||
// Convert the value to a string
|
||||
let mut buf = [0u8; 20];
|
||||
let mut buf = Cursor::new(&mut buf[..]);
|
||||
write!(&mut buf, "{}", val)?;
|
||||
|
||||
let pos = buf.position() as usize;
|
||||
self.stream.write_all(&buf.get_ref()[..pos]).await?;
|
||||
self.stream.write_all(b"\r\n").await?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,378 @@
|
|||
use tokio::sync::{broadcast, Notify};
|
||||
use tokio::time::{self, Duration, Instant};
|
||||
|
||||
use bytes::Bytes;
|
||||
use std::collections::{BTreeMap, HashMap};
|
||||
use std::sync::{Arc, Mutex};
|
||||
use tracing::debug;
|
||||
|
||||
/// A wrapper around a `Db` instance. This exists to allow orderly cleanup
|
||||
/// of the `Db` by signalling the background purge task to shut down when
|
||||
/// this struct is dropped.
|
||||
#[derive(Debug)]
|
||||
pub(crate) struct DbDropGuard {
|
||||
/// The `Db` instance that will be shut down when this `DbHolder` struct
|
||||
/// is dropped.
|
||||
db: Db,
|
||||
}
|
||||
|
||||
/// Server state shared across all connections.
|
||||
///
|
||||
/// `Db` contains a `HashMap` storing the key/value data and all
|
||||
/// `broadcast::Sender` values for active pub/sub channels.
|
||||
///
|
||||
/// A `Db` instance is a handle to shared state. Cloning `Db` is shallow and
|
||||
/// only incurs an atomic ref count increment.
|
||||
///
|
||||
/// When a `Db` value is created, a background task is spawned. This task is
|
||||
/// used to expire values after the requested duration has elapsed. The task
|
||||
/// runs until all instances of `Db` are dropped, at which point the task
|
||||
/// terminates.
|
||||
#[derive(Debug, Clone)]
|
||||
pub(crate) struct Db {
|
||||
/// Handle to shared state. The background task will also have an
|
||||
/// `Arc<Shared>`.
|
||||
shared: Arc<Shared>,
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Shared {
|
||||
/// The shared state is guarded by a mutex. This is a `std::sync::Mutex` and
|
||||
/// not a Tokio mutex. This is because there are no asynchronous operations
|
||||
/// being performed while holding the mutex. Additionally, the critical
|
||||
/// sections are very small.
|
||||
///
|
||||
/// A Tokio mutex is mostly intended to be used when locks need to be held
|
||||
/// across `.await` yield points. All other cases are **usually** best
|
||||
/// served by a std mutex. If the critical section does not include any
|
||||
/// async operations but is long (CPU intensive or performing blocking
|
||||
/// operations), then the entire operation, including waiting for the mutex,
|
||||
/// is considered a "blocking" operation and `tokio::task::spawn_blocking`
|
||||
/// should be used.
|
||||
state: Mutex<State>,
|
||||
|
||||
/// Notifies the background task handling entry expiration. The background
|
||||
/// task waits on this to be notified, then checks for expired values or the
|
||||
/// shutdown signal.
|
||||
background_task: Notify,
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct State {
|
||||
/// The key-value data. We are not trying to do anything fancy so a
|
||||
/// `std::collections::HashMap` works fine.
|
||||
entries: HashMap<String, Entry>,
|
||||
|
||||
/// The pub/sub key-space. Redis uses a **separate** key space for key-value
|
||||
/// and pub/sub. `mini-redis` handles this by using a separate `HashMap`.
|
||||
pub_sub: HashMap<String, broadcast::Sender<Bytes>>,
|
||||
|
||||
/// Tracks key TTLs.
|
||||
///
|
||||
/// A `BTreeMap` is used to maintain expirations sorted by when they expire.
|
||||
/// This allows the background task to iterate this map to find the value
|
||||
/// expiring next.
|
||||
///
|
||||
/// While highly unlikely, it is possible for more than one expiration to be
|
||||
/// created for the same instant. Because of this, the `Instant` is
|
||||
/// insufficient for the key. A unique expiration identifier (`u64`) is used
|
||||
/// to break these ties.
|
||||
expirations: BTreeMap<(Instant, u64), String>,
|
||||
|
||||
/// Identifier to use for the next expiration. Each expiration is associated
|
||||
/// with a unique identifier. See above for why.
|
||||
next_id: u64,
|
||||
|
||||
/// True when the Db instance is shutting down. This happens when all `Db`
|
||||
/// values drop. Setting this to `true` signals to the background task to
|
||||
/// exit.
|
||||
shutdown: bool,
|
||||
}
|
||||
|
||||
/// Entry in the key-value store
|
||||
#[derive(Debug)]
|
||||
struct Entry {
|
||||
/// Uniquely identifies this entry.
|
||||
id: u64,
|
||||
|
||||
/// Stored data
|
||||
data: Bytes,
|
||||
|
||||
/// Instant at which the entry expires and should be removed from the
|
||||
/// database.
|
||||
expires_at: Option<Instant>,
|
||||
}
|
||||
|
||||
impl DbDropGuard {
|
||||
/// Create a new `DbHolder`, wrapping a `Db` instance. When this is dropped
|
||||
/// the `Db`'s purge task will be shut down.
|
||||
pub(crate) fn new() -> DbDropGuard {
|
||||
DbDropGuard { db: Db::new() }
|
||||
}
|
||||
|
||||
/// Get the shared database. Internally, this is an
|
||||
/// `Arc`, so a clone only increments the ref count.
|
||||
pub(crate) fn db(&self) -> Db {
|
||||
self.db.clone()
|
||||
}
|
||||
}
|
||||
|
||||
impl Drop for DbDropGuard {
|
||||
fn drop(&mut self) {
|
||||
// Signal the 'Db' instance to shut down the task that purges expired keys
|
||||
self.db.shutdown_purge_task();
|
||||
}
|
||||
}
|
||||
|
||||
impl Db {
|
||||
/// Create a new, empty, `Db` instance. Allocates shared state and spawns a
|
||||
/// background task to manage key expiration.
|
||||
pub(crate) fn new() -> Db {
|
||||
let shared = Arc::new(Shared {
|
||||
state: Mutex::new(State {
|
||||
entries: HashMap::new(),
|
||||
pub_sub: HashMap::new(),
|
||||
expirations: BTreeMap::new(),
|
||||
next_id: 0,
|
||||
shutdown: false,
|
||||
}),
|
||||
background_task: Notify::new(),
|
||||
});
|
||||
|
||||
// Start the background task.
|
||||
tokio::spawn(purge_expired_tasks(shared.clone()));
|
||||
|
||||
Db { shared }
|
||||
}
|
||||
|
||||
/// Get the value associated with a key.
|
||||
///
|
||||
/// Returns `None` if there is no value associated with the key. This may be
|
||||
/// due to never having assigned a value to the key or a previously assigned
|
||||
/// value expired.
|
||||
pub(crate) fn get(&self, key: &str) -> Option<Bytes> {
|
||||
// Acquire the lock, get the entry and clone the value.
|
||||
//
|
||||
// Because data is stored using `Bytes`, a clone here is a shallow
|
||||
// clone. Data is not copied.
|
||||
let state = self.shared.state.lock().unwrap();
|
||||
state.entries.get(key).map(|entry| entry.data.clone())
|
||||
}
|
||||
|
||||
/// Set the value associated with a key along with an optional expiration
|
||||
/// Duration.
|
||||
///
|
||||
/// If a value is already associated with the key, it is removed.
|
||||
pub(crate) fn set(&self, key: String, value: Bytes, expire: Option<Duration>) {
|
||||
let mut state = self.shared.state.lock().unwrap();
|
||||
|
||||
// Get and increment the next insertion ID. Guarded by the lock, this
|
||||
// ensures a unique identifier is associated with each `set` operation.
|
||||
let id = state.next_id;
|
||||
state.next_id += 1;
|
||||
|
||||
// If this `set` becomes the key that expires **next**, the background
|
||||
// task needs to be notified so it can update its state.
|
||||
//
|
||||
// Whether or not the task needs to be notified is computed during the
|
||||
// `set` routine.
|
||||
let mut notify = false;
|
||||
|
||||
let expires_at = expire.map(|duration| {
|
||||
// `Instant` at which the key expires.
|
||||
let when = Instant::now() + duration;
|
||||
|
||||
// Only notify the worker task if the newly inserted expiration is the
|
||||
// **next** key to evict. In this case, the worker needs to be woken up
|
||||
// to update its state.
|
||||
notify = state
|
||||
.next_expiration()
|
||||
.map(|expiration| expiration > when)
|
||||
.unwrap_or(true);
|
||||
|
||||
// Track the expiration.
|
||||
state.expirations.insert((when, id), key.clone());
|
||||
when
|
||||
});
|
||||
|
||||
// Insert the entry into the `HashMap`.
|
||||
let prev = state.entries.insert(
|
||||
key,
|
||||
Entry {
|
||||
id,
|
||||
data: value,
|
||||
expires_at,
|
||||
},
|
||||
);
|
||||
|
||||
// If there was a value previously associated with the key **and** it
|
||||
// had an expiration time. The associated entry in the `expirations` map
|
||||
// must also be removed. This avoids leaking data.
|
||||
if let Some(prev) = prev {
|
||||
if let Some(when) = prev.expires_at {
|
||||
// clear expiration
|
||||
state.expirations.remove(&(when, prev.id));
|
||||
}
|
||||
}
|
||||
|
||||
// Release the mutex before notifying the background task. This helps
|
||||
// reduce contention by avoiding the background task waking up only to
|
||||
// be unable to acquire the mutex due to this function still holding it.
|
||||
drop(state);
|
||||
|
||||
if notify {
|
||||
// Finally, only notify the background task if it needs to update
|
||||
// its state to reflect a new expiration.
|
||||
self.shared.background_task.notify_one();
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns a `Receiver` for the requested channel.
|
||||
///
|
||||
/// The returned `Receiver` is used to receive values broadcast by `PUBLISH`
|
||||
/// commands.
|
||||
pub(crate) fn subscribe(&self, key: String) -> broadcast::Receiver<Bytes> {
|
||||
use std::collections::hash_map::Entry;
|
||||
|
||||
// Acquire the mutex
|
||||
let mut state = self.shared.state.lock().unwrap();
|
||||
|
||||
// If there is no entry for the requested channel, then create a new
|
||||
// broadcast channel and associate it with the key. If one already
|
||||
// exists, return an associated receiver.
|
||||
match state.pub_sub.entry(key) {
|
||||
Entry::Occupied(e) => e.get().subscribe(),
|
||||
Entry::Vacant(e) => {
|
||||
// No broadcast channel exists yet, so create one.
|
||||
//
|
||||
// The channel is created with a capacity of `1024` messages. A
|
||||
// message is stored in the channel until **all** subscribers
|
||||
// have seen it. This means that a slow subscriber could result
|
||||
// in messages being held indefinitely.
|
||||
//
|
||||
// When the channel's capacity fills up, publishing will result
|
||||
// in old messages being dropped. This prevents slow consumers
|
||||
// from blocking the entire system.
|
||||
let (tx, rx) = broadcast::channel(1024);
|
||||
e.insert(tx);
|
||||
rx
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Publish a message to the channel. Returns the number of subscribers
|
||||
/// listening on the channel.
|
||||
pub(crate) fn publish(&self, key: &str, value: Bytes) -> usize {
|
||||
let state = self.shared.state.lock().unwrap();
|
||||
|
||||
state
|
||||
.pub_sub
|
||||
.get(key)
|
||||
// On a successful message send on the broadcast channel, the number
|
||||
// of subscribers is returned. An error indicates there are no
|
||||
// receivers, in which case, `0` should be returned.
|
||||
.map(|tx| tx.send(value).unwrap_or(0))
|
||||
// If there is no entry for the channel key, then there are no
|
||||
// subscribers. In this case, return `0`.
|
||||
.unwrap_or(0)
|
||||
}
|
||||
|
||||
/// Signals the purge background task to shut down. This is called by the
|
||||
/// `DbShutdown`s `Drop` implementation.
|
||||
fn shutdown_purge_task(&self) {
|
||||
// The background task must be signaled to shut down. This is done by
|
||||
// setting `State::shutdown` to `true` and signalling the task.
|
||||
let mut state = self.shared.state.lock().unwrap();
|
||||
state.shutdown = true;
|
||||
|
||||
// Drop the lock before signalling the background task. This helps
|
||||
// reduce lock contention by ensuring the background task doesn't
|
||||
// wake up only to be unable to acquire the mutex.
|
||||
drop(state);
|
||||
self.shared.background_task.notify_one();
|
||||
}
|
||||
}
|
||||
|
||||
impl Shared {
|
||||
/// Purge all expired keys and return the `Instant` at which the **next**
|
||||
/// key will expire. The background task will sleep until this instant.
|
||||
fn purge_expired_keys(&self) -> Option<Instant> {
|
||||
let mut state = self.state.lock().unwrap();
|
||||
|
||||
if state.shutdown {
|
||||
// The database is shutting down. All handles to the shared state
|
||||
// have dropped. The background task should exit.
|
||||
return None;
|
||||
}
|
||||
|
||||
// This is needed to make the borrow checker happy. In short, `lock()`
|
||||
// returns a `MutexGuard` and not a `&mut State`. The borrow checker is
|
||||
// not able to see "through" the mutex guard and determine that it is
|
||||
// safe to access both `state.expirations` and `state.entries` mutably,
|
||||
// so we get a "real" mutable reference to `State` outside of the loop.
|
||||
let state = &mut *state;
|
||||
|
||||
// Find all keys scheduled to expire **before** now.
|
||||
let now = Instant::now();
|
||||
|
||||
while let Some((&(when, id), key)) = state.expirations.iter().next() {
|
||||
if when > now {
|
||||
// Done purging, `when` is the instant at which the next key
|
||||
// expires. The worker task will wait until this instant.
|
||||
return Some(when);
|
||||
}
|
||||
|
||||
// The key expired, remove it
|
||||
state.entries.remove(key);
|
||||
state.expirations.remove(&(when, id));
|
||||
}
|
||||
|
||||
None
|
||||
}
|
||||
|
||||
/// Returns `true` if the database is shutting down
|
||||
///
|
||||
/// The `shutdown` flag is set when all `Db` values have dropped, indicating
|
||||
/// that the shared state can no longer be accessed.
|
||||
fn is_shutdown(&self) -> bool {
|
||||
self.state.lock().unwrap().shutdown
|
||||
}
|
||||
}
|
||||
|
||||
impl State {
|
||||
fn next_expiration(&self) -> Option<Instant> {
|
||||
self.expirations
|
||||
.keys()
|
||||
.next()
|
||||
.map(|expiration| expiration.0)
|
||||
}
|
||||
}
|
||||
|
||||
/// Routine executed by the background task.
|
||||
///
|
||||
/// Wait to be notified. On notification, purge any expired keys from the shared
|
||||
/// state handle. If `shutdown` is set, terminate the task.
|
||||
async fn purge_expired_tasks(shared: Arc<Shared>) {
|
||||
// If the shutdown flag is set, then the task should exit.
|
||||
while !shared.is_shutdown() {
|
||||
// Purge all keys that are expired. The function returns the instant at
|
||||
// which the **next** key will expire. The worker should wait until the
|
||||
// instant has passed then purge again.
|
||||
if let Some(when) = shared.purge_expired_keys() {
|
||||
// Wait until the next key expires **or** until the background task
|
||||
// is notified. If the task is notified, then it must reload its
|
||||
// state as new keys have been set to expire early. This is done by
|
||||
// looping.
|
||||
tokio::select! {
|
||||
_ = time::sleep_until(when) => {}
|
||||
_ = shared.background_task.notified() => {}
|
||||
}
|
||||
} else {
|
||||
// There are no keys expiring in the future. Wait until the task is
|
||||
// notified.
|
||||
shared.background_task.notified().await;
|
||||
}
|
||||
}
|
||||
|
||||
debug!("Purge background task shut down")
|
||||
}
|
||||
|
|
@ -0,0 +1,300 @@
|
|||
//! Provides a type representing a Redis protocol frame as well as utilities for
|
||||
//! parsing frames from a byte array.
|
||||
|
||||
use bytes::{Buf, Bytes};
|
||||
use std::convert::TryInto;
|
||||
use std::fmt;
|
||||
use std::io::Cursor;
|
||||
use std::num::TryFromIntError;
|
||||
use std::string::FromUtf8Error;
|
||||
|
||||
/// A frame in the Redis protocol.
|
||||
#[derive(Clone, Debug)]
|
||||
pub enum Frame {
|
||||
Simple(String),
|
||||
Error(String),
|
||||
Integer(u64),
|
||||
Bulk(Bytes),
|
||||
Null,
|
||||
Array(Vec<Frame>),
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
pub enum Error {
|
||||
/// Not enough data is available to parse a message
|
||||
Incomplete,
|
||||
|
||||
/// Invalid message encoding
|
||||
Other(crate::Error),
|
||||
}
|
||||
|
||||
impl Frame {
|
||||
/// Returns an empty array
|
||||
pub(crate) fn array() -> Frame {
|
||||
Frame::Array(vec![])
|
||||
}
|
||||
|
||||
/// Push a "bulk" frame into the array. `self` must be an Array frame.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// panics if `self` is not an array
|
||||
pub(crate) fn push_bulk(&mut self, bytes: Bytes) {
|
||||
match self {
|
||||
Frame::Array(vec) => {
|
||||
vec.push(Frame::Bulk(bytes));
|
||||
}
|
||||
_ => panic!("not an array frame"),
|
||||
}
|
||||
}
|
||||
|
||||
/// Push an "integer" frame into the array. `self` must be an Array frame.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// panics if `self` is not an array
|
||||
pub(crate) fn push_int(&mut self, value: u64) {
|
||||
match self {
|
||||
Frame::Array(vec) => {
|
||||
vec.push(Frame::Integer(value));
|
||||
}
|
||||
_ => panic!("not an array frame"),
|
||||
}
|
||||
}
|
||||
|
||||
/// Checks if an entire message can be decoded from `src`
|
||||
pub fn check(src: &mut Cursor<&[u8]>) -> Result<(), Error> {
|
||||
match get_u8(src)? {
|
||||
b'+' => {
|
||||
get_line(src)?;
|
||||
Ok(())
|
||||
}
|
||||
b'-' => {
|
||||
get_line(src)?;
|
||||
Ok(())
|
||||
}
|
||||
b':' => {
|
||||
let _ = get_decimal(src)?;
|
||||
Ok(())
|
||||
}
|
||||
b'$' => {
|
||||
if b'-' == peek_u8(src)? {
|
||||
// Skip '-1\r\n'
|
||||
skip(src, 4)
|
||||
} else {
|
||||
// Read the bulk string
|
||||
let len: usize = get_decimal(src)?.try_into()?;
|
||||
|
||||
// skip that number of bytes + 2 (\r\n).
|
||||
skip(src, len + 2)
|
||||
}
|
||||
}
|
||||
b'*' => {
|
||||
let len = get_decimal(src)?;
|
||||
|
||||
for _ in 0..len {
|
||||
Frame::check(src)?;
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
actual => Err(format!("protocol error; invalid frame type byte `{}`", actual).into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// The message has already been validated with `check`.
|
||||
pub fn parse(src: &mut Cursor<&[u8]>) -> Result<Frame, Error> {
|
||||
match get_u8(src)? {
|
||||
b'+' => {
|
||||
// Read the line and convert it to `Vec<u8>`
|
||||
let line = get_line(src)?.to_vec();
|
||||
|
||||
// Convert the line to a String
|
||||
let string = String::from_utf8(line)?;
|
||||
|
||||
Ok(Frame::Simple(string))
|
||||
}
|
||||
b'-' => {
|
||||
// Read the line and convert it to `Vec<u8>`
|
||||
let line = get_line(src)?.to_vec();
|
||||
|
||||
// Convert the line to a String
|
||||
let string = String::from_utf8(line)?;
|
||||
|
||||
Ok(Frame::Error(string))
|
||||
}
|
||||
b':' => {
|
||||
let len = get_decimal(src)?;
|
||||
Ok(Frame::Integer(len))
|
||||
}
|
||||
b'$' => {
|
||||
if b'-' == peek_u8(src)? {
|
||||
let line = get_line(src)?;
|
||||
|
||||
if line != b"-1" {
|
||||
return Err("protocol error; invalid frame format".into());
|
||||
}
|
||||
|
||||
Ok(Frame::Null)
|
||||
} else {
|
||||
// Read the bulk string
|
||||
let len = get_decimal(src)?.try_into()?;
|
||||
let n = len + 2;
|
||||
|
||||
if src.remaining() < n {
|
||||
return Err(Error::Incomplete);
|
||||
}
|
||||
|
||||
let data = Bytes::copy_from_slice(&src.chunk()[..len]);
|
||||
|
||||
// skip that number of bytes + 2 (\r\n).
|
||||
skip(src, n)?;
|
||||
|
||||
Ok(Frame::Bulk(data))
|
||||
}
|
||||
}
|
||||
b'*' => {
|
||||
let len = get_decimal(src)?.try_into()?;
|
||||
let mut out = Vec::with_capacity(len);
|
||||
|
||||
for _ in 0..len {
|
||||
out.push(Frame::parse(src)?);
|
||||
}
|
||||
|
||||
Ok(Frame::Array(out))
|
||||
}
|
||||
_ => unimplemented!(),
|
||||
}
|
||||
}
|
||||
|
||||
/// Converts the frame to an "unexpected frame" error
|
||||
pub(crate) fn to_error(&self) -> crate::Error {
|
||||
format!("unexpected frame: {}", self).into()
|
||||
}
|
||||
}
|
||||
|
||||
impl PartialEq<&str> for Frame {
|
||||
fn eq(&self, other: &&str) -> bool {
|
||||
match self {
|
||||
Frame::Simple(s) => s.eq(other),
|
||||
Frame::Bulk(s) => s.eq(other),
|
||||
_ => false,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl fmt::Display for Frame {
|
||||
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
|
||||
use std::str;
|
||||
|
||||
match self {
|
||||
Frame::Simple(response) => response.fmt(fmt),
|
||||
Frame::Error(msg) => write!(fmt, "error: {}", msg),
|
||||
Frame::Integer(num) => num.fmt(fmt),
|
||||
Frame::Bulk(msg) => match str::from_utf8(msg) {
|
||||
Ok(string) => string.fmt(fmt),
|
||||
Err(_) => write!(fmt, "{:?}", msg),
|
||||
},
|
||||
Frame::Null => "(nil)".fmt(fmt),
|
||||
Frame::Array(parts) => {
|
||||
for (i, part) in parts.iter().enumerate() {
|
||||
if i > 0 {
|
||||
write!(fmt, " ")?;
|
||||
part.fmt(fmt)?;
|
||||
}
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn peek_u8(src: &mut Cursor<&[u8]>) -> Result<u8, Error> {
|
||||
if !src.has_remaining() {
|
||||
return Err(Error::Incomplete);
|
||||
}
|
||||
|
||||
Ok(src.chunk()[0])
|
||||
}
|
||||
|
||||
fn get_u8(src: &mut Cursor<&[u8]>) -> Result<u8, Error> {
|
||||
if !src.has_remaining() {
|
||||
return Err(Error::Incomplete);
|
||||
}
|
||||
|
||||
Ok(src.get_u8())
|
||||
}
|
||||
|
||||
fn skip(src: &mut Cursor<&[u8]>, n: usize) -> Result<(), Error> {
|
||||
if src.remaining() < n {
|
||||
return Err(Error::Incomplete);
|
||||
}
|
||||
|
||||
src.advance(n);
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Read a new-line terminated decimal
|
||||
fn get_decimal(src: &mut Cursor<&[u8]>) -> Result<u64, Error> {
|
||||
use atoi::atoi;
|
||||
|
||||
let line = get_line(src)?;
|
||||
|
||||
atoi::<u64>(line).ok_or_else(|| "protocol error; invalid frame format".into())
|
||||
}
|
||||
|
||||
/// Find a line
|
||||
fn get_line<'a>(src: &mut Cursor<&'a [u8]>) -> Result<&'a [u8], Error> {
|
||||
// Scan the bytes directly
|
||||
let start = src.position() as usize;
|
||||
// Scan to the second to last byte
|
||||
let end = src.get_ref().len() - 1;
|
||||
|
||||
for i in start..end {
|
||||
if src.get_ref()[i] == b'\r' && src.get_ref()[i + 1] == b'\n' {
|
||||
// We found a line, update the position to be *after* the \n
|
||||
src.set_position((i + 2) as u64);
|
||||
|
||||
// Return the line
|
||||
return Ok(&src.get_ref()[start..i]);
|
||||
}
|
||||
}
|
||||
|
||||
Err(Error::Incomplete)
|
||||
}
|
||||
|
||||
impl From<String> for Error {
|
||||
fn from(src: String) -> Error {
|
||||
Error::Other(src.into())
|
||||
}
|
||||
}
|
||||
|
||||
impl From<&str> for Error {
|
||||
fn from(src: &str) -> Error {
|
||||
src.to_string().into()
|
||||
}
|
||||
}
|
||||
|
||||
impl From<FromUtf8Error> for Error {
|
||||
fn from(_src: FromUtf8Error) -> Error {
|
||||
"protocol error; invalid frame format".into()
|
||||
}
|
||||
}
|
||||
|
||||
impl From<TryFromIntError> for Error {
|
||||
fn from(_src: TryFromIntError) -> Error {
|
||||
"protocol error; invalid frame format".into()
|
||||
}
|
||||
}
|
||||
|
||||
impl std::error::Error for Error {}
|
||||
|
||||
impl fmt::Display for Error {
|
||||
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
|
||||
match self {
|
||||
Error::Incomplete => "stream ended early".fmt(fmt),
|
||||
Error::Other(err) => err.fmt(fmt),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,76 @@
|
|||
//! A minimal (i.e. very incomplete) implementation of a Redis server and
|
||||
//! client.
|
||||
//!
|
||||
//! The purpose of this project is to provide a larger example of an
|
||||
//! asynchronous Rust project built with Tokio. Do not attempt to run this in
|
||||
//! production... seriously.
|
||||
//!
|
||||
//! # Layout
|
||||
//!
|
||||
//! The library is structured such that it can be used with guides. There are
|
||||
//! modules that are public that probably would not be public in a "real" redis
|
||||
//! client library.
|
||||
//!
|
||||
//! The major components are:
|
||||
//!
|
||||
//! * `server`: Redis server implementation. Includes a single `run` function
|
||||
//! that takes a `TcpListener` and starts accepting redis client connections.
|
||||
//!
|
||||
//! * `client`: an asynchronous Redis client implementation. Demonstrates how to
|
||||
//! build clients with Tokio.
|
||||
//!
|
||||
//! * `cmd`: implementations of the supported Redis commands.
|
||||
//!
|
||||
//! * `frame`: represents a single Redis protocol frame. A frame is used as an
|
||||
//! intermediate representation between a "command" and the byte
|
||||
//! representation.
|
||||
|
||||
pub mod blocking_client;
|
||||
pub mod client;
|
||||
|
||||
pub mod cmd;
|
||||
pub use cmd::Command;
|
||||
|
||||
mod connection;
|
||||
pub use connection::Connection;
|
||||
|
||||
pub mod frame;
|
||||
pub use frame::Frame;
|
||||
|
||||
mod db;
|
||||
use db::Db;
|
||||
use db::DbDropGuard;
|
||||
|
||||
mod parse;
|
||||
use parse::{Parse, ParseError};
|
||||
|
||||
pub mod server;
|
||||
|
||||
mod buffer;
|
||||
pub use buffer::{buffer, Buffer};
|
||||
|
||||
mod shutdown;
|
||||
use shutdown::Shutdown;
|
||||
|
||||
/// Default port that a redis server listens on.
|
||||
///
|
||||
/// Used if no port is specified.
|
||||
pub const DEFAULT_PORT: &str = "6379";
|
||||
|
||||
/// Error returned by most functions.
|
||||
///
|
||||
/// When writing a real application, one might want to consider a specialized
|
||||
/// error handling crate or defining an error type as an `enum` of causes.
|
||||
/// However, for our example, using a boxed `std::error::Error` is sufficient.
|
||||
///
|
||||
/// For performance reasons, boxing is avoided in any hot path. For example, in
|
||||
/// `parse`, a custom error `enum` is defined. This is because the error is hit
|
||||
/// and handled during normal execution when a partial frame is received on a
|
||||
/// socket. `std::error::Error` is implemented for `parse::Error` which allows
|
||||
/// it to be converted to `Box<dyn std::error::Error>`.
|
||||
pub type Error = Box<dyn std::error::Error + Send + Sync>;
|
||||
|
||||
/// A specialized `Result` type for mini-redis operations.
|
||||
///
|
||||
/// This is defined as a convenience.
|
||||
pub type Result<T> = std::result::Result<T, Error>;
|
||||
|
|
@ -0,0 +1,152 @@
|
|||
use crate::Frame;
|
||||
|
||||
use bytes::Bytes;
|
||||
use std::{fmt, str, vec};
|
||||
|
||||
/// Utility for parsing a command
|
||||
///
|
||||
/// Commands are represented as array frames. Each entry in the frame is a
|
||||
/// "token". A `Parse` is initialized with the array frame and provides a
|
||||
/// cursor-like API. Each command struct includes a `parse_frame` method that
|
||||
/// uses a `Parse` to extract its fields.
|
||||
#[derive(Debug)]
|
||||
pub(crate) struct Parse {
|
||||
/// Array frame iterator.
|
||||
parts: vec::IntoIter<Frame>,
|
||||
}
|
||||
|
||||
/// Error encountered while parsing a frame.
|
||||
///
|
||||
/// Only `EndOfStream` errors are handled at runtime. All other errors result in
|
||||
/// the connection being terminated.
|
||||
#[derive(Debug)]
|
||||
pub(crate) enum ParseError {
|
||||
/// Attempting to extract a value failed due to the frame being fully
|
||||
/// consumed.
|
||||
EndOfStream,
|
||||
|
||||
/// All other errors
|
||||
Other(crate::Error),
|
||||
}
|
||||
|
||||
impl Parse {
|
||||
/// Create a new `Parse` to parse the contents of `frame`.
|
||||
///
|
||||
/// Returns `Err` if `frame` is not an array frame.
|
||||
pub(crate) fn new(frame: Frame) -> Result<Parse, ParseError> {
|
||||
let array = match frame {
|
||||
Frame::Array(array) => array,
|
||||
frame => return Err(format!("protocol error; expected array, got {:?}", frame).into()),
|
||||
};
|
||||
|
||||
Ok(Parse {
|
||||
parts: array.into_iter(),
|
||||
})
|
||||
}
|
||||
|
||||
/// Return the next entry. Array frames are arrays of frames, so the next
|
||||
/// entry is a frame.
|
||||
fn next(&mut self) -> Result<Frame, ParseError> {
|
||||
self
|
||||
.parts
|
||||
.next()
|
||||
.ok_or(ParseError::EndOfStream)
|
||||
}
|
||||
|
||||
/// Return the next entry as a string.
|
||||
///
|
||||
/// If the next entry cannot be represented as a String, then an error is returned.
|
||||
pub(crate) fn next_string(&mut self) -> Result<String, ParseError> {
|
||||
match self.next()? {
|
||||
// Both `Simple` and `Bulk` representation may be strings. Strings
|
||||
// are parsed to UTF-8.
|
||||
//
|
||||
// While errors are stored as strings, they are considered separate
|
||||
// types.
|
||||
Frame::Simple(s) => Ok(s),
|
||||
Frame::Bulk(data) => str::from_utf8(&data[..])
|
||||
.map(|s| s.to_string())
|
||||
.map_err(|_| "protocol error; invalid string".into()),
|
||||
frame => Err(format!(
|
||||
"protocol error; expected simple frame or bulk frame, got {:?}",
|
||||
frame
|
||||
)
|
||||
.into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Return the next entry as raw bytes.
|
||||
///
|
||||
/// If the next entry cannot be represented as raw bytes, an error is
|
||||
/// returned.
|
||||
pub(crate) fn next_bytes(&mut self) -> Result<Bytes, ParseError> {
|
||||
match self.next()? {
|
||||
// Both `Simple` and `Bulk` representation may be raw bytes.
|
||||
//
|
||||
// Although errors are stored as strings and could be represented as
|
||||
// raw bytes, they are considered separate types.
|
||||
Frame::Simple(s) => Ok(Bytes::from(s.into_bytes())),
|
||||
Frame::Bulk(data) => Ok(data),
|
||||
frame => Err(format!(
|
||||
"protocol error; expected simple frame or bulk frame, got {:?}",
|
||||
frame
|
||||
)
|
||||
.into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Return the next entry as an integer.
|
||||
///
|
||||
/// This includes `Simple`, `Bulk`, and `Integer` frame types. `Simple` and
|
||||
/// `Bulk` frame types are parsed.
|
||||
///
|
||||
/// If the next entry cannot be represented as an integer, then an error is
|
||||
/// returned.
|
||||
pub(crate) fn next_int(&mut self) -> Result<u64, ParseError> {
|
||||
use atoi::atoi;
|
||||
|
||||
const MSG: &str = "protocol error; invalid number";
|
||||
|
||||
match self.next()? {
|
||||
// An integer frame type is already stored as an integer.
|
||||
Frame::Integer(v) => Ok(v),
|
||||
// Simple and bulk frames must be parsed as integers. If the parsing
|
||||
// fails, an error is returned.
|
||||
Frame::Simple(data) => atoi::<u64>(data.as_bytes()).ok_or_else(|| MSG.into()),
|
||||
Frame::Bulk(data) => atoi::<u64>(&data).ok_or_else(|| MSG.into()),
|
||||
frame => Err(format!("protocol error; expected int frame but got {:?}", frame).into()),
|
||||
}
|
||||
}
|
||||
|
||||
/// Ensure there are no more entries in the array
|
||||
pub(crate) fn finish(&mut self) -> Result<(), ParseError> {
|
||||
if self.parts.next().is_none() {
|
||||
Ok(())
|
||||
} else {
|
||||
Err("protocol error; expected end of frame, but there was more".into())
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl From<String> for ParseError {
|
||||
fn from(src: String) -> ParseError {
|
||||
ParseError::Other(src.into())
|
||||
}
|
||||
}
|
||||
|
||||
impl From<&str> for ParseError {
|
||||
fn from(src: &str) -> ParseError {
|
||||
src.to_string().into()
|
||||
}
|
||||
}
|
||||
|
||||
impl fmt::Display for ParseError {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
match self {
|
||||
ParseError::EndOfStream => "protocol error; unexpected end of stream".fmt(f),
|
||||
ParseError::Other(err) => err.fmt(f),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl std::error::Error for ParseError {}
|
||||
|
|
@ -0,0 +1,399 @@
|
|||
//! Minimal Redis server implementation
|
||||
//!
|
||||
//! Provides an async `run` function that listens for inbound connections,
|
||||
//! spawning a task per connection.
|
||||
|
||||
use crate::{Command, Connection, Db, DbDropGuard, Shutdown};
|
||||
|
||||
use std::future::Future;
|
||||
use std::sync::Arc;
|
||||
use tokio::net::{TcpListener, TcpStream};
|
||||
use tokio::sync::{broadcast, mpsc, Semaphore};
|
||||
use tokio::time::{self, Duration};
|
||||
use tracing::{debug, error, info, instrument};
|
||||
|
||||
/// Server listener state. Created in the `run` call. It includes a `run` method
|
||||
/// which performs the TCP listening and initialization of per-connection state.
|
||||
#[derive(Debug)]
|
||||
struct Listener {
|
||||
/// Shared database handle.
|
||||
///
|
||||
/// Contains the key / value store as well as the broadcast channels for
|
||||
/// pub/sub.
|
||||
///
|
||||
/// This holds a wrapper around an `Arc`. The internal `Db` can be
|
||||
/// retrieved and passed into the per connection state (`Handler`).
|
||||
db_holder: DbDropGuard,
|
||||
|
||||
/// TCP listener supplied by the `run` caller.
|
||||
listener: TcpListener,
|
||||
|
||||
/// Limit the max number of connections.
|
||||
///
|
||||
/// A `Semaphore` is used to limit the max number of connections. Before
|
||||
/// attempting to accept a new connection, a permit is acquired from the
|
||||
/// semaphore. If none are available, the listener waits for one.
|
||||
///
|
||||
/// When handlers complete processing a connection, the permit is returned
|
||||
/// to the semaphore.
|
||||
limit_connections: Arc<Semaphore>,
|
||||
|
||||
/// Broadcasts a shutdown signal to all active connections.
|
||||
///
|
||||
/// The initial `shutdown` trigger is provided by the `run` caller. The
|
||||
/// server is responsible for gracefully shutting down active connections.
|
||||
/// When a connection task is spawned, it is passed a broadcast receiver
|
||||
/// handle. When a graceful shutdown is initiated, a `()` value is sent via
|
||||
/// the broadcast::Sender. Each active connection receives it, reaches a
|
||||
/// safe terminal state, and completes the task.
|
||||
notify_shutdown: broadcast::Sender<()>,
|
||||
|
||||
/// Used as part of the graceful shutdown process to wait for client
|
||||
/// connections to complete processing.
|
||||
///
|
||||
/// Tokio channels are closed once all `Sender` handles go out of scope.
|
||||
/// When a channel is closed, the receiver receives `None`. This is
|
||||
/// leveraged to detect all connection handlers completing. When a
|
||||
/// connection handler is initialized, it is assigned a clone of
|
||||
/// `shutdown_complete_tx`. When the listener shuts down, it drops the
|
||||
/// sender held by this `shutdown_complete_tx` field. Once all handler tasks
|
||||
/// complete, all clones of the `Sender` are also dropped. This results in
|
||||
/// `shutdown_complete_rx.recv()` completing with `None`. At this point, it
|
||||
/// is safe to exit the server process.
|
||||
shutdown_complete_rx: mpsc::Receiver<()>,
|
||||
shutdown_complete_tx: mpsc::Sender<()>,
|
||||
}
|
||||
|
||||
/// Per-connection handler. Reads requests from `connection` and applies the
|
||||
/// commands to `db`.
|
||||
#[derive(Debug)]
|
||||
struct Handler {
|
||||
/// Shared database handle.
|
||||
///
|
||||
/// When a command is received from `connection`, it is applied with `db`.
|
||||
/// The implementation of the command is in the `cmd` module. Each command
|
||||
/// will need to interact with `db` in order to complete the work.
|
||||
db: Db,
|
||||
|
||||
/// The TCP connection decorated with the redis protocol encoder / decoder
|
||||
/// implemented using a buffered `TcpStream`.
|
||||
///
|
||||
/// When `Listener` receives an inbound connection, the `TcpStream` is
|
||||
/// passed to `Connection::new`, which initializes the associated buffers.
|
||||
/// `Connection` allows the handler to operate at the "frame" level and keep
|
||||
/// the byte level protocol parsing details encapsulated in `Connection`.
|
||||
connection: Connection,
|
||||
|
||||
/// Max connection semaphore.
|
||||
///
|
||||
/// When the handler is dropped, a permit is returned to this semaphore. If
|
||||
/// the listener is waiting for connections to close, it will be notified of
|
||||
/// the newly available permit and resume accepting connections.
|
||||
limit_connections: Arc<Semaphore>,
|
||||
|
||||
/// Listen for shutdown notifications.
|
||||
///
|
||||
/// A wrapper around the `broadcast::Receiver` paired with the sender in
|
||||
/// `Listener`. The connection handler processes requests from the
|
||||
/// connection until the peer disconnects **or** a shutdown notification is
|
||||
/// received from `shutdown`. In the latter case, any in-flight work being
|
||||
/// processed for the peer is continued until it reaches a safe state, at
|
||||
/// which point the connection is terminated.
|
||||
shutdown: Shutdown,
|
||||
|
||||
/// Not used directly. Instead, when `Handler` is dropped...?
|
||||
_shutdown_complete: mpsc::Sender<()>,
|
||||
}
|
||||
|
||||
/// Maximum number of concurrent connections the redis server will accept.
|
||||
///
|
||||
/// When this limit is reached, the server will stop accepting connections until
|
||||
/// an active connection terminates.
|
||||
///
|
||||
/// A real application will want to make this value configurable, but for this
|
||||
/// example, it is hard coded.
|
||||
///
|
||||
/// This is also set to a pretty low value to discourage using this in
|
||||
/// production (you'd think that all the disclaimers would make it obvious that
|
||||
/// this is not a serious project... but I thought that about mini-http as
|
||||
/// well).
|
||||
const MAX_CONNECTIONS: usize = 250;
|
||||
|
||||
/// Run the mini-redis server.
|
||||
///
|
||||
/// Accepts connections from the supplied listener. For each inbound connection,
|
||||
/// a task is spawned to handle that connection. The server runs until the
|
||||
/// `shutdown` future completes, at which point the server shuts down
|
||||
/// gracefully.
|
||||
///
|
||||
/// `tokio::signal::ctrl_c()` can be used as the `shutdown` argument. This will
|
||||
/// listen for a SIGINT signal.
|
||||
pub async fn run(listener: TcpListener, shutdown: impl Future) {
|
||||
// When the provided `shutdown` future completes, we must send a shutdown
|
||||
// message to all active connections. We use a broadcast channel for this
|
||||
// purpose. The call below ignores the receiver of the broadcast pair, and when
|
||||
// a receiver is needed, the subscribe() method on the sender is used to create
|
||||
// one.
|
||||
let (notify_shutdown, _) = broadcast::channel(1);
|
||||
|
||||
let (shutdown_complete_tx, shutdown_complete_rx) = mpsc::channel(1);
|
||||
|
||||
// Initialize the listener state
|
||||
let mut server = Listener {
|
||||
listener,
|
||||
db_holder: DbDropGuard::new(),
|
||||
limit_connections: Arc::new(Semaphore::new(MAX_CONNECTIONS)),
|
||||
notify_shutdown,
|
||||
shutdown_complete_tx,
|
||||
shutdown_complete_rx,
|
||||
};
|
||||
|
||||
// Concurrently run the server and listen for the `shutdown` signal. The
|
||||
// server task runs until an error is encountered, so under normal
|
||||
// circumstances, this `select!` statement runs until the `shutdown` signal
|
||||
// is received.
|
||||
//
|
||||
// `select!` statements are written in the form of:
|
||||
//
|
||||
// ```
|
||||
// <result of async op> = <async op> => <step to perform with result>
|
||||
// ```
|
||||
//
|
||||
// All `<async op>` statements are executed concurrently. Once the **first**
|
||||
// op completes, its associated `<step to perform with result>` is
|
||||
// performed.
|
||||
//
|
||||
// The `select! macro is a foundational building block for writing
|
||||
// asynchronous Rust. See the API docs for more details:
|
||||
//
|
||||
// https://docs.rs/tokio/*/tokio/macro.select.html
|
||||
tokio::select! {
|
||||
res = server.run() => {
|
||||
// If an error is received here, accepting connections from the TCP
|
||||
// listener failed multiple times and the server is giving up and
|
||||
// shutting down.
|
||||
//
|
||||
// Errors encountered when handling individual connections do not
|
||||
// bubble up to this point.
|
||||
if let Err(err) = res {
|
||||
error!(cause = %err, "failed to accept");
|
||||
}
|
||||
}
|
||||
_ = shutdown => {
|
||||
// The shutdown signal has been received.
|
||||
info!("shutting down");
|
||||
}
|
||||
}
|
||||
|
||||
// Extract the `shutdown_complete` receiver and transmitter
|
||||
// explicitly drop `shutdown_transmitter`. This is important, as the
|
||||
// `.await` below would otherwise never complete.
|
||||
let Listener {
|
||||
mut shutdown_complete_rx,
|
||||
shutdown_complete_tx,
|
||||
notify_shutdown,
|
||||
..
|
||||
} = server;
|
||||
|
||||
// When `notify_shutdown` is dropped, all tasks which have `subscribe`d will
|
||||
// receive the shutdown signal and can exit
|
||||
drop(notify_shutdown);
|
||||
// Drop final `Sender` so the `Receiver` below can complete
|
||||
drop(shutdown_complete_tx);
|
||||
|
||||
// Wait for all active connections to finish processing. As the `Sender`
|
||||
// handle held by the listener has been dropped above, the only remaining
|
||||
// `Sender` instances are held by connection handler tasks. When those drop,
|
||||
// the `mpsc` channel will close and `recv()` will return `None`.
|
||||
let _ = shutdown_complete_rx.recv().await;
|
||||
}
|
||||
|
||||
impl Listener {
|
||||
/// Run the server
|
||||
///
|
||||
/// Listen for inbound connections. For each inbound connection, spawn a
|
||||
/// task to process that connection.
|
||||
///
|
||||
/// # Errors
|
||||
///
|
||||
/// Returns `Err` if accepting returns an error. This can happen for a
|
||||
/// number reasons that resolve over time. For example, if the underlying
|
||||
/// operating system has reached an internal limit for max number of
|
||||
/// sockets, accept will fail.
|
||||
///
|
||||
/// The process is not able to detect when a transient error resolves
|
||||
/// itself. One strategy for handling this is to implement a back off
|
||||
/// strategy, which is what we do here.
|
||||
async fn run(&mut self) -> crate::Result<()> {
|
||||
info!("accepting inbound connections");
|
||||
|
||||
loop {
|
||||
// Wait for a permit to become available
|
||||
//
|
||||
// `acquire` returns a permit that is bound via a lifetime to the
|
||||
// semaphore. When the permit value is dropped, it is automatically
|
||||
// returned to the semaphore. This is convenient in many cases.
|
||||
// However, in this case, the permit must be returned in a different
|
||||
// task than it is acquired in (the handler task). To do this, we
|
||||
// "forget" the permit, which drops the permit value **without**
|
||||
// incrementing the semaphore's permits. Then, in the handler task
|
||||
// we manually add a new permit when processing completes.
|
||||
//
|
||||
// `acquire()` returns `Err` when the semaphore has been closed. We
|
||||
// don't ever close the sempahore, so `unwrap()` is safe.
|
||||
self.limit_connections.acquire().await.unwrap().forget();
|
||||
|
||||
// Accept a new socket. This will attempt to perform error handling.
|
||||
// The `accept` method internally attempts to recover errors, so an
|
||||
// error here is non-recoverable.
|
||||
let socket = self.accept().await?;
|
||||
|
||||
// Create the necessary per-connection handler state.
|
||||
let mut handler = Handler {
|
||||
// Get a handle to the shared database.
|
||||
db: self.db_holder.db(),
|
||||
|
||||
// Initialize the connection state. This allocates read/write
|
||||
// buffers to perform redis protocol frame parsing.
|
||||
connection: Connection::new(socket),
|
||||
|
||||
// The connection state needs a handle to the max connections
|
||||
// semaphore. When the handler is done processing the
|
||||
// connection, a permit is added back to the semaphore.
|
||||
limit_connections: self.limit_connections.clone(),
|
||||
|
||||
// Receive shutdown notifications.
|
||||
shutdown: Shutdown::new(self.notify_shutdown.subscribe()),
|
||||
|
||||
// Notifies the receiver half once all clones are
|
||||
// dropped.
|
||||
_shutdown_complete: self.shutdown_complete_tx.clone(),
|
||||
};
|
||||
|
||||
// Spawn a new task to process the connections. Tokio tasks are like
|
||||
// asynchronous green threads and are executed concurrently.
|
||||
tokio::spawn(async move {
|
||||
// Process the connection. If an error is encountered, log it.
|
||||
if let Err(err) = handler.run().await {
|
||||
error!(cause = ?err, "connection error");
|
||||
}
|
||||
});
|
||||
}
|
||||
}
|
||||
|
||||
/// Accept an inbound connection.
|
||||
///
|
||||
/// Errors are handled by backing off and retrying. An exponential backoff
|
||||
/// strategy is used. After the first failure, the task waits for 1 second.
|
||||
/// After the second failure, the task waits for 2 seconds. Each subsequent
|
||||
/// failure doubles the wait time. If accepting fails on the 6th try after
|
||||
/// waiting for 64 seconds, then this function returns with an error.
|
||||
async fn accept(&mut self) -> crate::Result<TcpStream> {
|
||||
let mut backoff = 1;
|
||||
|
||||
// Try to accept a few times
|
||||
loop {
|
||||
// Perform the accept operation. If a socket is successfully
|
||||
// accepted, return it. Otherwise, save the error.
|
||||
match self.listener.accept().await {
|
||||
Ok((socket, _)) => return Ok(socket),
|
||||
Err(err) => {
|
||||
if backoff > 64 {
|
||||
// Accept has failed too many times. Return the error.
|
||||
return Err(err.into());
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Pause execution until the back off period elapses.
|
||||
time::sleep(Duration::from_secs(backoff)).await;
|
||||
|
||||
// Double the back off
|
||||
backoff *= 2;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl Handler {
|
||||
/// Process a single connection.
|
||||
///
|
||||
/// Request frames are read from the socket and processed. Responses are
|
||||
/// written back to the socket.
|
||||
///
|
||||
/// Currently, pipelining is not implemented. Pipelining is the ability to
|
||||
/// process more than one request concurrently per connection without
|
||||
/// interleaving frames. See for more details:
|
||||
/// https://redis.io/topics/pipelining
|
||||
///
|
||||
/// When the shutdown signal is received, the connection is processed until
|
||||
/// it reaches a safe state, at which point it is terminated.
|
||||
#[instrument(skip(self))]
|
||||
async fn run(&mut self) -> crate::Result<()> {
|
||||
// As long as the shutdown signal has not been received, try to read a
|
||||
// new request frame.
|
||||
while !self.shutdown.is_shutdown() {
|
||||
// While reading a request frame, also listen for the shutdown
|
||||
// signal.
|
||||
let maybe_frame = tokio::select! {
|
||||
res = self.connection.read_frame() => res?,
|
||||
_ = self.shutdown.recv() => {
|
||||
// If a shutdown signal is received, return from `run`.
|
||||
// This will result in the task terminating.
|
||||
return Ok(());
|
||||
}
|
||||
};
|
||||
|
||||
// If `None` is returned from `read_frame()` then the peer closed
|
||||
// the socket. There is no further work to do and the task can be
|
||||
// terminated.
|
||||
let frame = match maybe_frame {
|
||||
Some(frame) => frame,
|
||||
None => return Ok(()),
|
||||
};
|
||||
|
||||
// Convert the redis frame into a command struct. This returns an
|
||||
// error if the frame is not a valid redis command or it is an
|
||||
// unsupported command.
|
||||
let cmd = Command::from_frame(frame)?;
|
||||
|
||||
// Logs the `cmd` object. The syntax here is a shorthand provided by
|
||||
// the `tracing` crate. It can be thought of as similar to:
|
||||
//
|
||||
// ```
|
||||
// debug!(cmd = format!("{:?}", cmd));
|
||||
// ```
|
||||
//
|
||||
// `tracing` provides structured logging, so information is "logged"
|
||||
// as key-value pairs.
|
||||
debug!(?cmd);
|
||||
|
||||
// Perform the work needed to apply the command. This may mutate the
|
||||
// database state as a result.
|
||||
//
|
||||
// The connection is passed into the apply function which allows the
|
||||
// command to write response frames directly to the connection. In
|
||||
// the case of pub/sub, multiple frames may be send back to the
|
||||
// peer.
|
||||
cmd.apply(&self.db, &mut self.connection, &mut self.shutdown)
|
||||
.await?;
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
||||
impl Drop for Handler {
|
||||
fn drop(&mut self) {
|
||||
// Add a permit back to the semaphore.
|
||||
//
|
||||
// Doing so unblocks the listener if the max number of
|
||||
// connections has been reached.
|
||||
//
|
||||
// This is done in a `Drop` implementation in order to guarantee that
|
||||
// the permit is added even if the task handling the connection panics.
|
||||
// If `add_permit` was called at the end of the `run` function and some
|
||||
// bug causes a panic. The permit would never be returned to the
|
||||
// semaphore.
|
||||
self.limit_connections.add_permits(1);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,49 @@
|
|||
use tokio::sync::broadcast;
|
||||
|
||||
/// Listens for the server shutdown signal.
|
||||
///
|
||||
/// Shutdown is signalled using a `broadcast::Receiver`. Only a single value is
|
||||
/// ever sent. Once a value has been sent via the broadcast channel, the server
|
||||
/// should shutdown.
|
||||
///
|
||||
/// The `Shutdown` struct listens for the signal and tracks that the signal has
|
||||
/// been received. Callers may query for whether the shutdown signal has been
|
||||
/// received or not.
|
||||
#[derive(Debug)]
|
||||
pub(crate) struct Shutdown {
|
||||
/// `true` if the shutdown signal has been received
|
||||
shutdown: bool,
|
||||
|
||||
/// The receive half of the channel used to listen for shutdown.
|
||||
notify: broadcast::Receiver<()>,
|
||||
}
|
||||
|
||||
impl Shutdown {
|
||||
/// Create a new `Shutdown` backed by the given `broadcast::Receiver`.
|
||||
pub(crate) fn new(notify: broadcast::Receiver<()>) -> Shutdown {
|
||||
Shutdown {
|
||||
shutdown: false,
|
||||
notify,
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns `true` if the shutdown signal has been received.
|
||||
pub(crate) fn is_shutdown(&self) -> bool {
|
||||
self.shutdown
|
||||
}
|
||||
|
||||
/// Receive the shutdown notice, waiting if necessary.
|
||||
pub(crate) async fn recv(&mut self) {
|
||||
// If the shutdown signal has already been received, then return
|
||||
// immediately.
|
||||
if self.shutdown {
|
||||
return;
|
||||
}
|
||||
|
||||
// Cannot receive a "lag error" as only one value is ever sent.
|
||||
let _ = self.notify.recv().await;
|
||||
|
||||
// Remember that the signal has been received.
|
||||
self.shutdown = true;
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,30 @@
|
|||
use mini_redis::{buffer, client, server};
|
||||
use std::net::SocketAddr;
|
||||
use tokio::net::TcpListener;
|
||||
use tokio::task::JoinHandle;
|
||||
|
||||
/// A basic "hello world" style test. A server instance is started in a
|
||||
/// background task. A client instance is then established and used to intialize
|
||||
/// the buffer. Set and get commands are sent to the server. The response is
|
||||
/// then evaluated.
|
||||
#[tokio::test]
|
||||
async fn pool_key_value_get_set() {
|
||||
let (addr, _) = start_server().await;
|
||||
|
||||
let client = client::connect(addr).await.unwrap();
|
||||
let mut client = buffer(client);
|
||||
|
||||
client.set("hello", "world".into()).await.unwrap();
|
||||
|
||||
let value = client.get("hello").await.unwrap().unwrap();
|
||||
assert_eq!(b"world", &value[..])
|
||||
}
|
||||
|
||||
async fn start_server() -> (SocketAddr, JoinHandle<()>) {
|
||||
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
|
||||
let addr = listener.local_addr().unwrap();
|
||||
|
||||
let handle = tokio::spawn(async move { server::run(listener, tokio::signal::ctrl_c()).await });
|
||||
|
||||
(addr, handle)
|
||||
}
|
||||
|
|
@ -0,0 +1,92 @@
|
|||
use mini_redis::{client, server};
|
||||
use std::net::SocketAddr;
|
||||
use tokio::net::TcpListener;
|
||||
use tokio::task::JoinHandle;
|
||||
|
||||
/// A basic "hello world" style test. A server instance is started in a
|
||||
/// background task. A client instance is then established and set and get
|
||||
/// commands are sent to the server. The response is then evaluated
|
||||
#[tokio::test]
|
||||
async fn key_value_get_set() {
|
||||
let (addr, _) = start_server().await;
|
||||
|
||||
let mut client = client::connect(addr).await.unwrap();
|
||||
client.set("hello", "world".into()).await.unwrap();
|
||||
|
||||
let value = client.get("hello").await.unwrap().unwrap();
|
||||
assert_eq!(b"world", &value[..])
|
||||
}
|
||||
|
||||
/// similar to the "hello world" style test, But this time
|
||||
/// a single channel subscription will be tested instead
|
||||
#[tokio::test]
|
||||
async fn receive_message_subscribed_channel() {
|
||||
let (addr, _) = start_server().await;
|
||||
|
||||
let client = client::connect(addr.clone()).await.unwrap();
|
||||
let mut subscriber = client.subscribe(vec!["hello".into()]).await.unwrap();
|
||||
|
||||
tokio::spawn(async move {
|
||||
let mut client = client::connect(addr).await.unwrap();
|
||||
client.publish("hello", "world".into()).await.unwrap()
|
||||
});
|
||||
|
||||
let message = subscriber.next_message().await.unwrap().unwrap();
|
||||
assert_eq!("hello", &message.channel);
|
||||
assert_eq!(b"world", &message.content[..])
|
||||
}
|
||||
|
||||
/// test that a client gets messages from multiple subscribed channels
|
||||
#[tokio::test]
|
||||
async fn receive_message_multiple_subscribed_channels() {
|
||||
let (addr, _) = start_server().await;
|
||||
|
||||
let client = client::connect(addr.clone()).await.unwrap();
|
||||
let mut subscriber = client
|
||||
.subscribe(vec!["hello".into(), "world".into()])
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
tokio::spawn(async move {
|
||||
let mut client = client::connect(addr).await.unwrap();
|
||||
client.publish("hello", "world".into()).await.unwrap()
|
||||
});
|
||||
|
||||
let message1 = subscriber.next_message().await.unwrap().unwrap();
|
||||
assert_eq!("hello", &message1.channel);
|
||||
assert_eq!(b"world", &message1.content[..]);
|
||||
|
||||
tokio::spawn(async move {
|
||||
let mut client = client::connect(addr).await.unwrap();
|
||||
client.publish("world", "howdy?".into()).await.unwrap()
|
||||
});
|
||||
|
||||
let message2 = subscriber.next_message().await.unwrap().unwrap();
|
||||
assert_eq!("world", &message2.channel);
|
||||
assert_eq!(b"howdy?", &message2.content[..])
|
||||
}
|
||||
|
||||
/// test that a client accurately removes its own subscribed chanel list
|
||||
/// when unbscribing to all subscribed channels by submitting an empty vec
|
||||
#[tokio::test]
|
||||
async fn unsubscribes_from_channels() {
|
||||
let (addr, _) = start_server().await;
|
||||
|
||||
let client = client::connect(addr.clone()).await.unwrap();
|
||||
let mut subscriber = client
|
||||
.subscribe(vec!["hello".into(), "world".into()])
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
subscriber.unsubscribe(&[]).await.unwrap();
|
||||
assert_eq!(subscriber.get_subscribed().len(), 0);
|
||||
}
|
||||
|
||||
async fn start_server() -> (SocketAddr, JoinHandle<()>) {
|
||||
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
|
||||
let addr = listener.local_addr().unwrap();
|
||||
|
||||
let handle = tokio::spawn(async move { server::run(listener, tokio::signal::ctrl_c()).await });
|
||||
|
||||
(addr, handle)
|
||||
}
|
||||
|
|
@ -0,0 +1,407 @@
|
|||
use mini_redis::server;
|
||||
|
||||
use std::net::SocketAddr;
|
||||
use tokio::io::{AsyncReadExt, AsyncWriteExt};
|
||||
use tokio::net::{TcpListener, TcpStream};
|
||||
use tokio::time::{self, Duration};
|
||||
|
||||
/// A basic "hello world" style test. A server instance is started in a
|
||||
/// background task. A client TCP connection is then established and raw redis
|
||||
/// commands are sent to the server. The response is evaluated at the byte
|
||||
/// level.
|
||||
#[tokio::test]
|
||||
async fn key_value_get_set() {
|
||||
let addr = start_server().await;
|
||||
|
||||
// Establish a connection to the server
|
||||
let mut stream = TcpStream::connect(addr).await.unwrap();
|
||||
|
||||
// Get a key, data is missing
|
||||
stream
|
||||
.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read nil response
|
||||
let mut response = [0; 5];
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b"$-1\r\n", &response);
|
||||
|
||||
// Set a key
|
||||
stream
|
||||
.write_all(b"*3\r\n$3\r\nSET\r\n$5\r\nhello\r\n$5\r\nworld\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read OK
|
||||
let mut response = [0; 5];
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b"+OK\r\n", &response);
|
||||
|
||||
// Get the key, data is present
|
||||
stream
|
||||
.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Shutdown the write half
|
||||
stream.shutdown().await.unwrap();
|
||||
|
||||
// Read "world" response
|
||||
let mut response = [0; 11];
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b"$5\r\nworld\r\n", &response);
|
||||
|
||||
// Receive `None`
|
||||
assert_eq!(0, stream.read(&mut response).await.unwrap());
|
||||
}
|
||||
|
||||
/// Similar to the basic key-value test, however, this time timeouts will be
|
||||
/// tested. This test demonstrates how to test time related behavior.
|
||||
///
|
||||
/// When writing tests, it is useful to remove sources of non-determinism. Time
|
||||
/// is a source of non-determinism. Here, we "pause" time using the
|
||||
/// `time::pause()` function. This function is available with the `test-util`
|
||||
/// feature flag. This allows us to deterministically control how time appears
|
||||
/// to advance to the application.
|
||||
#[tokio::test]
|
||||
async fn key_value_timeout() {
|
||||
tokio::time::pause();
|
||||
|
||||
let addr = start_server().await;
|
||||
|
||||
// Establish a connection to the server
|
||||
let mut stream = TcpStream::connect(addr).await.unwrap();
|
||||
|
||||
// Set a key
|
||||
stream
|
||||
.write_all(
|
||||
b"*5\r\n$3\r\nSET\r\n$5\r\nhello\r\n$5\r\nworld\r\n\
|
||||
+EX\r\n:1\r\n",
|
||||
)
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 5];
|
||||
|
||||
// Read OK
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
|
||||
assert_eq!(b"+OK\r\n", &response);
|
||||
|
||||
// Get the key, data is present
|
||||
stream
|
||||
.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read "world" response
|
||||
let mut response = [0; 11];
|
||||
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
|
||||
assert_eq!(b"$5\r\nworld\r\n", &response);
|
||||
|
||||
// Wait for the key to expire
|
||||
time::advance(Duration::from_secs(1)).await;
|
||||
|
||||
// Get a key, data is missing
|
||||
stream
|
||||
.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read nil response
|
||||
let mut response = [0; 5];
|
||||
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
|
||||
assert_eq!(b"$-1\r\n", &response);
|
||||
}
|
||||
|
||||
#[tokio::test]
|
||||
async fn pub_sub() {
|
||||
let addr = start_server().await;
|
||||
|
||||
let mut publisher = TcpStream::connect(addr).await.unwrap();
|
||||
|
||||
// Publish a message, there are no subscribers yet so the server will
|
||||
// return `0`.
|
||||
publisher
|
||||
.write_all(b"*3\r\n$7\r\nPUBLISH\r\n$5\r\nhello\r\n$5\r\nworld\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 4];
|
||||
publisher.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b":0\r\n", &response);
|
||||
|
||||
// Create a subscriber. This subscriber will only subscribe to the `hello`
|
||||
// channel.
|
||||
let mut sub1 = TcpStream::connect(addr).await.unwrap();
|
||||
sub1.write_all(b"*2\r\n$9\r\nSUBSCRIBE\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read the subscribe response
|
||||
let mut response = [0; 34];
|
||||
sub1.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$9\r\nsubscribe\r\n$5\r\nhello\r\n:1\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// Publish a message, there now is a subscriber
|
||||
publisher
|
||||
.write_all(b"*3\r\n$7\r\nPUBLISH\r\n$5\r\nhello\r\n$5\r\nworld\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 4];
|
||||
publisher.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b":1\r\n", &response);
|
||||
|
||||
// The first subscriber received the message
|
||||
let mut response = [0; 39];
|
||||
sub1.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$7\r\nmessage\r\n$5\r\nhello\r\n$5\r\nworld\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// Create a second subscriber
|
||||
//
|
||||
// This subscriber will be subscribed to both `hello` and `foo`
|
||||
let mut sub2 = TcpStream::connect(addr).await.unwrap();
|
||||
sub2.write_all(b"*3\r\n$9\r\nSUBSCRIBE\r\n$5\r\nhello\r\n$3\r\nfoo\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read the subscribe response
|
||||
let mut response = [0; 34];
|
||||
sub2.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$9\r\nsubscribe\r\n$5\r\nhello\r\n:1\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
let mut response = [0; 32];
|
||||
sub2.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$9\r\nsubscribe\r\n$3\r\nfoo\r\n:2\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// Publish another message on `hello`, there are two subscribers
|
||||
publisher
|
||||
.write_all(b"*3\r\n$7\r\nPUBLISH\r\n$5\r\nhello\r\n$5\r\njazzy\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 4];
|
||||
publisher.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b":2\r\n", &response);
|
||||
|
||||
// Publish a message on `foo`, there is only one subscriber
|
||||
publisher
|
||||
.write_all(b"*3\r\n$7\r\nPUBLISH\r\n$3\r\nfoo\r\n$3\r\nbar\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 4];
|
||||
publisher.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b":1\r\n", &response);
|
||||
|
||||
// The first subscriber received the message
|
||||
let mut response = [0; 39];
|
||||
sub1.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$7\r\nmessage\r\n$5\r\nhello\r\n$5\r\njazzy\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// The second subscriber received the message
|
||||
let mut response = [0; 39];
|
||||
sub2.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$7\r\nmessage\r\n$5\r\nhello\r\n$5\r\njazzy\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// The first subscriber **did not** receive the second message
|
||||
let mut response = [0; 1];
|
||||
time::timeout(Duration::from_millis(100), sub1.read(&mut response))
|
||||
.await
|
||||
.unwrap_err();
|
||||
|
||||
// The second subscriber **did** receive the message
|
||||
let mut response = [0; 35];
|
||||
sub2.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$7\r\nmessage\r\n$3\r\nfoo\r\n$3\r\nbar\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
}
|
||||
|
||||
#[tokio::test]
|
||||
async fn manage_subscription() {
|
||||
let addr = start_server().await;
|
||||
|
||||
let mut publisher = TcpStream::connect(addr).await.unwrap();
|
||||
|
||||
// Create a subscriber
|
||||
let mut sub = TcpStream::connect(addr).await.unwrap();
|
||||
sub.write_all(b"*2\r\n$9\r\nSUBSCRIBE\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
// Read the subscribe response
|
||||
let mut response = [0; 34];
|
||||
sub.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$9\r\nsubscribe\r\n$5\r\nhello\r\n:1\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// Update subscription to add `foo`
|
||||
sub.write_all(b"*2\r\n$9\r\nSUBSCRIBE\r\n$3\r\nfoo\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 32];
|
||||
sub.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$9\r\nsubscribe\r\n$3\r\nfoo\r\n:2\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// Update subscription to remove `hello`
|
||||
sub.write_all(b"*2\r\n$11\r\nUNSUBSCRIBE\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 37];
|
||||
sub.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$11\r\nunsubscribe\r\n$5\r\nhello\r\n:1\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// Publish a message to `hello` and then a message to `foo`
|
||||
publisher
|
||||
.write_all(b"*3\r\n$7\r\nPUBLISH\r\n$5\r\nhello\r\n$5\r\nworld\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
let mut response = [0; 4];
|
||||
publisher.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b":0\r\n", &response);
|
||||
|
||||
publisher
|
||||
.write_all(b"*3\r\n$7\r\nPUBLISH\r\n$3\r\nfoo\r\n$3\r\nbar\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
let mut response = [0; 4];
|
||||
publisher.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b":1\r\n", &response);
|
||||
|
||||
// Receive the message
|
||||
// The second subscriber **did** receive the message
|
||||
let mut response = [0; 35];
|
||||
sub.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$7\r\nmessage\r\n$3\r\nfoo\r\n$3\r\nbar\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
// No more messages
|
||||
let mut response = [0; 1];
|
||||
time::timeout(Duration::from_millis(100), sub.read(&mut response))
|
||||
.await
|
||||
.unwrap_err();
|
||||
|
||||
// Unsubscribe from all channels
|
||||
sub.write_all(b"*1\r\n$11\r\nunsubscribe\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 35];
|
||||
sub.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(
|
||||
&b"*3\r\n$11\r\nunsubscribe\r\n$3\r\nfoo\r\n:0\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
}
|
||||
|
||||
// In this case we test that server Responds with an Error message if a client
|
||||
// sends an unknown command
|
||||
#[tokio::test]
|
||||
async fn send_error_unknown_command() {
|
||||
let addr = start_server().await;
|
||||
|
||||
// Establish a connection to the server
|
||||
let mut stream = TcpStream::connect(addr).await.unwrap();
|
||||
|
||||
// Get a key, data is missing
|
||||
stream
|
||||
.write_all(b"*2\r\n$3\r\nFOO\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 28];
|
||||
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
|
||||
assert_eq!(b"-ERR unknown command \'foo\'\r\n", &response);
|
||||
}
|
||||
|
||||
// In this case we test that server Responds with an Error message if a client
|
||||
// sends an GET or SET command after a SUBSCRIBE
|
||||
#[tokio::test]
|
||||
async fn send_error_get_set_after_subscribe() {
|
||||
let addr = start_server().await;
|
||||
|
||||
let mut stream = TcpStream::connect(addr).await.unwrap();
|
||||
|
||||
// send SUBSCRIBE command
|
||||
stream
|
||||
.write_all(b"*2\r\n$9\r\nsubscribe\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 34];
|
||||
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
|
||||
assert_eq!(
|
||||
&b"*3\r\n$9\r\nsubscribe\r\n$5\r\nhello\r\n:1\r\n"[..],
|
||||
&response[..]
|
||||
);
|
||||
|
||||
stream
|
||||
.write_all(b"*3\r\n$3\r\nSET\r\n$5\r\nhello\r\n$5\r\nworld\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 28];
|
||||
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b"-ERR unknown command \'set\'\r\n", &response);
|
||||
|
||||
stream
|
||||
.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n")
|
||||
.await
|
||||
.unwrap();
|
||||
|
||||
let mut response = [0; 28];
|
||||
|
||||
stream.read_exact(&mut response).await.unwrap();
|
||||
assert_eq!(b"-ERR unknown command \'get\'\r\n", &response);
|
||||
}
|
||||
|
||||
async fn start_server() -> SocketAddr {
|
||||
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
|
||||
let addr = listener.local_addr().unwrap();
|
||||
|
||||
tokio::spawn(async move { server::run(listener, tokio::signal::ctrl_c()).await });
|
||||
|
||||
addr
|
||||
}
|
||||
Loading…
Reference in New Issue