redis/example_test.go

650 lines
13 KiB
Go

package redis_test
import (
"context"
"errors"
"fmt"
"sync"
"time"
"github.com/go-redis/redis/v8"
)
var (
ctx = context.Background()
rdb *redis.Client
)
func init() {
rdb = redis.NewClient(&redis.Options{
Addr: ":6379",
DialTimeout: 10 * time.Second,
ReadTimeout: 30 * time.Second,
WriteTimeout: 30 * time.Second,
PoolSize: 10,
PoolTimeout: 30 * time.Second,
})
}
func ExampleNewClient() {
rdb := redis.NewClient(&redis.Options{
Addr: "localhost:6379", // use default Addr
Password: "", // no password set
DB: 0, // use default DB
})
pong, err := rdb.Ping(ctx).Result()
fmt.Println(pong, err)
// Output: PONG <nil>
}
func ExampleParseURL() {
opt, err := redis.ParseURL("redis://:qwerty@localhost:6379/1?dial_timeout=5s")
if err != nil {
panic(err)
}
fmt.Println("addr is", opt.Addr)
fmt.Println("db is", opt.DB)
fmt.Println("password is", opt.Password)
fmt.Println("dial timeout is", opt.DialTimeout)
// Create client as usually.
_ = redis.NewClient(opt)
// Output: addr is localhost:6379
// db is 1
// password is qwerty
// dial timeout is 5s
}
func ExampleNewFailoverClient() {
// See http://redis.io/topics/sentinel for instructions how to
// setup Redis Sentinel.
rdb := redis.NewFailoverClient(&redis.FailoverOptions{
MasterName: "master",
SentinelAddrs: []string{":26379"},
})
rdb.Ping(ctx)
}
func ExampleNewClusterClient() {
// See http://redis.io/topics/cluster-tutorial for instructions
// how to setup Redis Cluster.
rdb := redis.NewClusterClient(&redis.ClusterOptions{
Addrs: []string{":7000", ":7001", ":7002", ":7003", ":7004", ":7005"},
})
rdb.Ping(ctx)
}
// Following example creates a cluster from 2 master nodes and 2 slave nodes
// without using cluster mode or Redis Sentinel.
func ExampleNewClusterClient_manualSetup() {
// clusterSlots returns cluster slots information.
// It can use service like ZooKeeper to maintain configuration information
// and Cluster.ReloadState to manually trigger state reloading.
clusterSlots := func(ctx context.Context) ([]redis.ClusterSlot, error) {
slots := []redis.ClusterSlot{
// First node with 1 master and 1 slave.
{
Start: 0,
End: 8191,
Nodes: []redis.ClusterNode{{
Addr: ":7000", // master
}, {
Addr: ":8000", // 1st slave
}},
},
// Second node with 1 master and 1 slave.
{
Start: 8192,
End: 16383,
Nodes: []redis.ClusterNode{{
Addr: ":7001", // master
}, {
Addr: ":8001", // 1st slave
}},
},
}
return slots, nil
}
rdb := redis.NewClusterClient(&redis.ClusterOptions{
ClusterSlots: clusterSlots,
RouteRandomly: true,
})
rdb.Ping(ctx)
// ReloadState reloads cluster state. It calls ClusterSlots func
// to get cluster slots information.
rdb.ReloadState(ctx)
}
func ExampleNewRing() {
rdb := redis.NewRing(&redis.RingOptions{
Addrs: map[string]string{
"shard1": ":7000",
"shard2": ":7001",
"shard3": ":7002",
},
})
rdb.Ping(ctx)
}
func ExampleClient() {
err := rdb.Set(ctx, "key", "value", 0).Err()
if err != nil {
panic(err)
}
val, err := rdb.Get(ctx, "key").Result()
if err != nil {
panic(err)
}
fmt.Println("key", val)
val2, err := rdb.Get(ctx, "missing_key").Result()
if err == redis.Nil {
fmt.Println("missing_key does not exist")
} else if err != nil {
panic(err)
} else {
fmt.Println("missing_key", val2)
}
// Output: key value
// missing_key does not exist
}
func ExampleConn() {
conn := rdb.Conn(context.Background())
err := conn.ClientSetName(ctx, "foobar").Err()
if err != nil {
panic(err)
}
// Open other connections.
for i := 0; i < 10; i++ {
go rdb.Ping(ctx)
}
s, err := conn.ClientGetName(ctx).Result()
if err != nil {
panic(err)
}
fmt.Println(s)
// Output: foobar
}
func ExampleClient_Set() {
// Last argument is expiration. Zero means the key has no
// expiration time.
err := rdb.Set(ctx, "key", "value", 0).Err()
if err != nil {
panic(err)
}
// key2 will expire in an hour.
err = rdb.Set(ctx, "key2", "value", time.Hour).Err()
if err != nil {
panic(err)
}
}
func ExampleClient_SetEX() {
err := rdb.SetEX(ctx, "key", "value", time.Hour).Err()
if err != nil {
panic(err)
}
}
func ExampleClient_HSet() {
// Set "redis" tag for hash key
type ExampleUser struct {
Name string `redis:"name"`
Age int `redis:"age"`
}
items := ExampleUser{"jane", 22}
err := rdb.HSet(ctx, "user:1", items).Err()
if err != nil {
panic(err)
}
}
func ExampleClient_Incr() {
result, err := rdb.Incr(ctx, "counter").Result()
if err != nil {
panic(err)
}
fmt.Println(result)
// Output: 1
}
func ExampleClient_BLPop() {
if err := rdb.RPush(ctx, "queue", "message").Err(); err != nil {
panic(err)
}
// use `rdb.BLPop(0, "queue")` for infinite waiting time
result, err := rdb.BLPop(ctx, 1*time.Second, "queue").Result()
if err != nil {
panic(err)
}
fmt.Println(result[0], result[1])
// Output: queue message
}
func ExampleClient_Scan() {
rdb.FlushDB(ctx)
for i := 0; i < 33; i++ {
err := rdb.Set(ctx, fmt.Sprintf("key%d", i), "value", 0).Err()
if err != nil {
panic(err)
}
}
var cursor uint64
var n int
for {
var keys []string
var err error
keys, cursor, err = rdb.Scan(ctx, cursor, "key*", 10).Result()
if err != nil {
panic(err)
}
n += len(keys)
if cursor == 0 {
break
}
}
fmt.Printf("found %d keys\n", n)
// Output: found 33 keys
}
func ExampleClient_ScanType() {
rdb.FlushDB(ctx)
for i := 0; i < 33; i++ {
err := rdb.Set(ctx, fmt.Sprintf("key%d", i), "value", 0).Err()
if err != nil {
panic(err)
}
}
var cursor uint64
var n int
for {
var keys []string
var err error
keys, cursor, err = rdb.ScanType(ctx, cursor, "key*", 10, "string").Result()
if err != nil {
panic(err)
}
n += len(keys)
if cursor == 0 {
break
}
}
fmt.Printf("found %d keys\n", n)
// Output: found 33 keys
}
// ExampleStringStringMapCmd_Scan shows how to scan the results of a map fetch
// into a struct.
func ExampleStringStringMapCmd_Scan() {
rdb.FlushDB(ctx)
err := rdb.HMSet(ctx, "map",
"name", "hello",
"count", 123,
"correct", true).Err()
if err != nil {
panic(err)
}
// Get the map. The same approach works for HmGet().
res := rdb.HGetAll(ctx, "map")
if res.Err() != nil {
panic(err)
}
type data struct {
Name string `redis:"name"`
Count int `redis:"count"`
Correct bool `redis:"correct"`
}
// Scan the results into the struct.
var d data
if err := res.Scan(&d); err != nil {
panic(err)
}
fmt.Println(d)
// Output: {hello 123 true}
}
// ExampleSliceCmd_Scan shows how to scan the results of a multi key fetch
// into a struct.
func ExampleSliceCmd_Scan() {
rdb.FlushDB(ctx)
err := rdb.MSet(ctx,
"name", "hello",
"count", 123,
"correct", true).Err()
if err != nil {
panic(err)
}
res := rdb.MGet(ctx, "name", "count", "empty", "correct")
if res.Err() != nil {
panic(err)
}
type data struct {
Name string `redis:"name"`
Count int `redis:"count"`
Correct bool `redis:"correct"`
}
// Scan the results into the struct.
var d data
if err := res.Scan(&d); err != nil {
panic(err)
}
fmt.Println(d)
// Output: {hello 123 true}
}
func ExampleClient_Pipelined() {
var incr *redis.IntCmd
_, err := rdb.Pipelined(ctx, func(pipe redis.Pipeliner) error {
incr = pipe.Incr(ctx, "pipelined_counter")
pipe.Expire(ctx, "pipelined_counter", time.Hour)
return nil
})
fmt.Println(incr.Val(), err)
// Output: 1 <nil>
}
func ExampleClient_Pipeline() {
pipe := rdb.Pipeline()
incr := pipe.Incr(ctx, "pipeline_counter")
pipe.Expire(ctx, "pipeline_counter", time.Hour)
// Execute
//
// INCR pipeline_counter
// EXPIRE pipeline_counts 3600
//
// using one rdb-server roundtrip.
_, err := pipe.Exec(ctx)
fmt.Println(incr.Val(), err)
// Output: 1 <nil>
}
func ExampleClient_TxPipelined() {
var incr *redis.IntCmd
_, err := rdb.TxPipelined(ctx, func(pipe redis.Pipeliner) error {
incr = pipe.Incr(ctx, "tx_pipelined_counter")
pipe.Expire(ctx, "tx_pipelined_counter", time.Hour)
return nil
})
fmt.Println(incr.Val(), err)
// Output: 1 <nil>
}
func ExampleClient_TxPipeline() {
pipe := rdb.TxPipeline()
incr := pipe.Incr(ctx, "tx_pipeline_counter")
pipe.Expire(ctx, "tx_pipeline_counter", time.Hour)
// Execute
//
// MULTI
// INCR pipeline_counter
// EXPIRE pipeline_counts 3600
// EXEC
//
// using one rdb-server roundtrip.
_, err := pipe.Exec(ctx)
fmt.Println(incr.Val(), err)
// Output: 1 <nil>
}
func ExampleClient_Watch() {
const maxRetries = 1000
// Increment transactionally increments key using GET and SET commands.
increment := func(key string) error {
// Transactional function.
txf := func(tx *redis.Tx) error {
// Get current value or zero.
n, err := tx.Get(ctx, key).Int()
if err != nil && err != redis.Nil {
return err
}
// Actual opperation (local in optimistic lock).
n++
// Operation is committed only if the watched keys remain unchanged.
_, err = tx.TxPipelined(ctx, func(pipe redis.Pipeliner) error {
pipe.Set(ctx, key, n, 0)
return nil
})
return err
}
for i := 0; i < maxRetries; i++ {
err := rdb.Watch(ctx, txf, key)
if err == nil {
// Success.
return nil
}
if err == redis.TxFailedErr {
// Optimistic lock lost. Retry.
continue
}
// Return any other error.
return err
}
return errors.New("increment reached maximum number of retries")
}
var wg sync.WaitGroup
for i := 0; i < 100; i++ {
wg.Add(1)
go func() {
defer wg.Done()
if err := increment("counter3"); err != nil {
fmt.Println("increment error:", err)
}
}()
}
wg.Wait()
n, err := rdb.Get(ctx, "counter3").Int()
fmt.Println("ended with", n, err)
// Output: ended with 100 <nil>
}
func ExamplePubSub() {
pubsub := rdb.Subscribe(ctx, "mychannel1")
// Wait for confirmation that subscription is created before publishing anything.
_, err := pubsub.Receive(ctx)
if err != nil {
panic(err)
}
// Go channel which receives messages.
ch := pubsub.Channel()
// Publish a message.
err = rdb.Publish(ctx, "mychannel1", "hello").Err()
if err != nil {
panic(err)
}
time.AfterFunc(time.Second, func() {
// When pubsub is closed channel is closed too.
_ = pubsub.Close()
})
// Consume messages.
for msg := range ch {
fmt.Println(msg.Channel, msg.Payload)
}
// Output: mychannel1 hello
}
func ExamplePubSub_Receive() {
pubsub := rdb.Subscribe(ctx, "mychannel2")
defer pubsub.Close()
for i := 0; i < 2; i++ {
// ReceiveTimeout is a low level API. Use ReceiveMessage instead.
msgi, err := pubsub.ReceiveTimeout(ctx, time.Second)
if err != nil {
break
}
switch msg := msgi.(type) {
case *redis.Subscription:
fmt.Println("subscribed to", msg.Channel)
_, err := rdb.Publish(ctx, "mychannel2", "hello").Result()
if err != nil {
panic(err)
}
case *redis.Message:
fmt.Println("received", msg.Payload, "from", msg.Channel)
default:
panic("unreached")
}
}
// sent message to 1 rdb
// received hello from mychannel2
}
func ExampleScript() {
IncrByXX := redis.NewScript(`
if redis.call("GET", KEYS[1]) ~= false then
return redis.call("INCRBY", KEYS[1], ARGV[1])
end
return false
`)
n, err := IncrByXX.Run(ctx, rdb, []string{"xx_counter"}, 2).Result()
fmt.Println(n, err)
err = rdb.Set(ctx, "xx_counter", "40", 0).Err()
if err != nil {
panic(err)
}
n, err = IncrByXX.Run(ctx, rdb, []string{"xx_counter"}, 2).Result()
fmt.Println(n, err)
// Output: <nil> redis: nil
// 42 <nil>
}
func Example_customCommand() {
Get := func(ctx context.Context, rdb *redis.Client, key string) *redis.StringCmd {
cmd := redis.NewStringCmd(ctx, "get", key)
rdb.Process(ctx, cmd)
return cmd
}
v, err := Get(ctx, rdb, "key_does_not_exist").Result()
fmt.Printf("%q %s", v, err)
// Output: "" redis: nil
}
func Example_customCommand2() {
v, err := rdb.Do(ctx, "get", "key_does_not_exist").Text()
fmt.Printf("%q %s", v, err)
// Output: "" redis: nil
}
func ExampleScanIterator() {
iter := rdb.Scan(ctx, 0, "", 0).Iterator()
for iter.Next(ctx) {
fmt.Println(iter.Val())
}
if err := iter.Err(); err != nil {
panic(err)
}
}
func ExampleScanCmd_Iterator() {
iter := rdb.Scan(ctx, 0, "", 0).Iterator()
for iter.Next(ctx) {
fmt.Println(iter.Val())
}
if err := iter.Err(); err != nil {
panic(err)
}
}
func ExampleNewUniversalClient_simple() {
rdb := redis.NewUniversalClient(&redis.UniversalOptions{
Addrs: []string{":6379"},
})
defer rdb.Close()
rdb.Ping(ctx)
}
func ExampleNewUniversalClient_failover() {
rdb := redis.NewUniversalClient(&redis.UniversalOptions{
MasterName: "master",
Addrs: []string{":26379"},
})
defer rdb.Close()
rdb.Ping(ctx)
}
func ExampleNewUniversalClient_cluster() {
rdb := redis.NewUniversalClient(&redis.UniversalOptions{
Addrs: []string{":7000", ":7001", ":7002", ":7003", ":7004", ":7005"},
})
defer rdb.Close()
rdb.Ping(ctx)
}
func ExampleClient_SlowLogGet() {
const key = "slowlog-log-slower-than"
old := rdb.ConfigGet(ctx, key).Val()
rdb.ConfigSet(ctx, key, "0")
defer rdb.ConfigSet(ctx, key, old[1].(string))
if err := rdb.Do(ctx, "slowlog", "reset").Err(); err != nil {
panic(err)
}
rdb.Set(ctx, "test", "true", 0)
result, err := rdb.SlowLogGet(ctx, -1).Result()
if err != nil {
panic(err)
}
fmt.Println(len(result))
// Output: 2
}