redis/README.md

3.9 KiB

Redis client for Golang

Supports:

  • Redis 2.6 commands except QUIT, MONITOR, SLOWLOG and SYNC.
  • Pub/sub.
  • Transactions.
  • Pipelining.
  • Connection pool.
  • TLS connections.
  • Thread safety.

API docs: http://godoc.org/github.com/vmihailenco/redis

Installation

Install:

go get github.com/vmihailenco/redis

Getting started

Let's start with connecting to Redis using TCP:

password := ""  // no password set
db := int64(-1) // use default DB
client := redis.NewTCPClient("localhost:6379", password, db)
defer client.Close()

ping := client.Ping()
fmt.Println(ping.Err(), ping.Val())
// Output: <nil> PONG

or using Unix socket:

client := redis.NewUnixClient("/tmp/redis.sock", "", -1)
defer client.Close()

ping := client.Ping()
fmt.Println(ping.Err(), ping.Val())
// Output: <nil> PONG

Then we can start sending commands:

set := client.Set("foo", "bar")
fmt.Println(set.Err(), set.Val())

get := client.Get("foo")
fmt.Println(get.Err(), get.Val())

// Output: <nil> OK
// <nil> bar

We can also pipeline two commands together:

var set *redis.StatusReq
var get *redis.StringReq
reqs, err := client.Pipelined(func(c *redis.PipelineClient) {
    set = c.Set("key1", "hello1")
    get = c.Get("key2")
})
fmt.Println(err, reqs)
fmt.Println(set)
fmt.Println(get)
// Output: <nil> [SET key1 hello1: OK GET key2: (nil)]
// SET key1 hello1: OK
// GET key2: (nil)

or:

var set *redis.StatusReq
var get *redis.StringReq
reqs, err := client.Pipelined(func(c *redis.PipelineClient) {
    set = c.Set("key1", "hello1")
    get = c.Get("key2")
})
fmt.Println(err, reqs)
fmt.Println(set)
fmt.Println(get)
// Output: <nil> [SET key1 hello1 GET key2]
// SET key1 hello1
// GET key2

We can also send several commands in transaction:

func transaction(multi *redis.MultiClient) ([]redis.Req, error) {
    get := multi.Get("key")
    if err := get.Err(); err != nil && err != redis.Nil {
        return nil, err
    }

    val, _ := strconv.ParseInt(get.Val(), 10, 64)

    reqs, err := multi.Exec(func() {
        multi.Set("key", strconv.FormatInt(val+1, 10))
    })
    // Transaction failed. Repeat.
    if err == redis.Nil {
        return transaction(multi)
    }
    return reqs, err
}

multi, err := client.MultiClient()
_ = err
defer multi.Close()

watch := multi.Watch("key")
_ = watch.Err()

reqs, err := transaction(multi)
fmt.Println(err, reqs)

// Output: <nil> [SET key 1: OK]

To subscribe to the channel:

pubsub, err := client.PubSubClient()
defer pubsub.Close()

ch, err := pubsub.Subscribe("mychannel")
_ = err

subscribeMsg := <-ch
fmt.Println(subscribeMsg.Err, subscribeMsg.Name)

pub := client.Publish("mychannel", "hello")
_ = pub.Err()

msg := <-ch
fmt.Println(msg.Err, msg.Message)

// Output: <nil> subscribe
// <nil> hello

You can also write custom commands:

func Get(client *redis.Client, key string) *redis.StringReq {
    req := redis.NewStringReq("GET", key)
    client.Process(req)
    return req
}

get := Get(client, "key_does_not_exist")
fmt.Println(get.Err(), get.Val())
// Output: (nil)

Client uses connection pool to send commands. You can change maximum number of connections with:

client.ConnPool.(*redis.MultiConnPool).MaxCap = 1

Look and feel

Some corner cases:

SORT list LIMIT 0 2 ASC
client.Sort("list", redis.Sort{Offset: 0, Count: 2, Order: "ASC"})

ZRANGEBYSCORE zset -inf +inf WITHSCORES LIMIT 0 2
client.ZRangeByScoreWithScores("zset", "-inf", "+inf", 0, 2)

ZINTERSTORE out 2 zset1 zset2 WEIGHTS 2 3 AGGREGATE SUM
client.ZInterStore("out", redis.ZStore{Weights: []int64{2, 3}}, "zset1", "zset2")

EVAL "return {KEYS[1],ARGV[1]}" 1 "key" "hello"
client.Eval("return {KEYS[1],ARGV[1]}", []string{"key"}, []string{"hello"})

Contributing

Configure Redis to allow maximum 10 clients:

maxclients 10

Run tests:

go test -gocheck.v

Run benchmarks:

go test -gocheck.b