Crate redis_asio

redis-asio is a Redis client library written in pure Rust based on asynchronous tokio library.

The library provides a base module for low-level request sending and response handling, and a stream module that contains specific interfaces for work with Redis-Stream "https://redis.io/topics/streams-intro".

The library works with binary-safe strings that allows users to serialize their message structures and send via RESP protocol "https://redis.io/topics/protocol".

Use in project

Depend on the redis-asio in project via Cargo:

[dependencies]
redis-async = "0.1"

Resolve the crate interfaces:

extern crate redis_asio;

Motivating examples

SET, GET value from cache

use std::net::SocketAddr;
use futures::Future;
use redis_asio::{RedisCoreConnection, RedisValue, command, from_redis_value};

let address = &"127.0.0.1:6379".parse::<SocketAddr>().unwrap();

let set_req = command("SET").arg("foo").arg(123);
let get_req = command("GET").arg("foo");

let future = RedisCoreConnection::connect(address)
    .and_then(move |con| {
        // send "SET foo 123" request
        con.send(set_req)
    })
    .and_then(|(con, response)| {
        // check if the value has been set
        assert_eq!(RedisValue::Ok, response);
        // send "GET foo" request
        con.send(get_req)
    })
    .map(move |(_, response)|
        // check if the received value is the same
        assert_eq!(123, from_redis_value(&response).unwrap()))
    .map_err(|_| unreachable!());
// start the Tokio runtime using the `future`
tokio::run(future);

Subscribe to a Redis Stream

Subscribe to a Redis stream and process all incoming entries. Redis Streams requires to send XREAD/XREADGROUP requests every time the client receives a response on the previous, in other words Redis Streams does not provide an interface to subscribe to a Redis stream.

In the Crate the subscription is possible by hidden requests sending within the Crate engine.

Request that will be sent to get new entries in the following example: "XREADGROUP GROUP mygroup Bob BLOCK 0 STREAMS mystream <"

use std::net::SocketAddr;
use futures::{Future, Stream};
use redis_asio::stream::{RedisStream, SubscribeOptions, StreamEntry,
                         RedisGroup};

let address = &"127.0.0.1:6379".parse::<SocketAddr>().unwrap();
// create options to pass it into RedisStream::subscribe()
let group_info = RedisGroup::new("mygroup".to_string(), "Bob".to_string());
let subscribe_options =
    SubscribeOptions::with_group(vec!["mystream".to_string()], group_info);

let future = RedisStream::connect(address)
    .and_then(move |stream: RedisStream| {
        stream.subscribe(subscribe_options)
    })
    .and_then(|subscribe| /*:Subscribe*/ {
        // pass the closure that will be called on each incoming entries
        subscribe.for_each(|entries: Vec<StreamEntry>| {
            for entry in entries.into_iter() {
                println!("Received: {:?}", entry);
            }
            Ok(())
        })
    })
    .map_err(|err| eprintln!("something went wrong: {}", err));
// start the Tokio runtime using the `future`
tokio::run(future);

Send an entry into a Redis Stream

Send an entry into a Redis stream. Request that will be sent to push a specified entry in the following example: "XADD mystream * type 3 data "Hello, world""

use std::net::SocketAddr;
use std::collections::HashMap;
use futures::Future;
use redis_asio::{RedisArgument, IntoRedisArgument};
use redis_asio::stream::{RedisStream, SendEntryOptions, EntryId};

let address = &"127.0.0.1:6379".parse::<SocketAddr>().unwrap();
// create options to pass it into RedisStream::send_entry()
let send_options = SendEntryOptions::new("mystream".to_string());

// create key-value pairs
let mut request: HashMap<String, RedisArgument> = HashMap::new();
request.insert("type".to_string(), 3i32.into_redis_argument());
request.insert("data".to_string(), "Hello, world!".into_redis_argument());

let future = RedisStream::connect(address)
    .and_then(move |stream: RedisStream| {
        // HashMap<String, RedisArgument> satisfies the
        // HashMap<String, ToRedisArgument>
        stream.send_entry(send_options, request)
    })
    .map(|(_, inserted_entry_id): (RedisStream, EntryId)| {
        println!("{:?} has sent", inserted_entry_id.to_string());
    })
    .map_err(|err| eprintln!("something went wrong: {}", err));
tokio::run(future);

Modules

stream

Stream module that contains specific interfaces for work with Redis-Stream "https://redis.io/topics/streams-intro".

Structs

RedisCommand	Redis command wrapper represents array of BulkStrings
RedisCoreConnection	Actual Redis connection converts packets from RESP packets into RedisValue and from RedisCommand into RESP packets.
RedisError

Enums

RedisArgument	Enumeration of base types that can be put into RedisCommand chain as argument.
RedisErrorKind
RedisValue	Set of types that are parsed to and from RESP binary packets. Represents RESP protocol: "https://redis.io/topics/protocol".

Traits

FromRedisValue	Trait interface requires to implement method to convert RedisValue into base type.
IntoRedisArgument	Trait interface requires to implement method to convert base type into RedisArgument.

Functions

command	Make a Redis command represents array of BulkStrings wrapped into RedisCommand.
from_redis_value	Convert RedisValue into T value.

Type Definitions

RedisResult