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package redisc_test
import (
"fmt"
"log"
"time"
"github.com/gomodule/redigo/redis"
"github.com/mna/redisc"
)
// Create and use a cluster.
func Example() {
// create the cluster
cluster := redisc.Cluster{
StartupNodes: []string{":7000", ":7001", ":7002"},
DialOptions: []redis.DialOption{redis.DialConnectTimeout(5 * time.Second)},
CreatePool: createPool,
}
defer cluster.Close()
// initialize its mapping
if err := cluster.Refresh(); err != nil {
log.Fatalf("Refresh failed: %v", err)
}
// grab a connection from the pool
conn := cluster.Get()
defer conn.Close()
// call commands on it
s, err := redis.String(conn.Do("GET", "some-key"))
if err != nil {
log.Fatalf("GET failed: %v", err)
}
log.Println(s)
// grab a non-pooled connection
conn2, err := cluster.Dial()
if err != nil {
log.Fatalf("Dial failed: %v", err)
}
defer conn2.Close()
// make it handle redirections automatically
rc, err := redisc.RetryConn(conn2, 3, 100*time.Millisecond)
if err != nil {
log.Fatalf("RetryConn failed: %v", err)
}
_, err = rc.Do("SET", "some-key", 2)
if err != nil {
log.Fatalf("SET failed: %v", err)
}
}
func createPool(addr string, opts ...redis.DialOption) (*redis.Pool, error) {
return &redis.Pool{
MaxIdle: 5,
MaxActive: 10,
IdleTimeout: time.Minute,
Dial: func() (redis.Conn, error) {
return redis.Dial("tcp", addr, opts...)
},
TestOnBorrow: func(c redis.Conn, t time.Time) error {
_, err := c.Do("PING")
return err
},
}, nil
}
// Execute scripts.
func ExampleConn() {
// create the cluster
cluster := redisc.Cluster{
StartupNodes: []string{":7000", ":7001", ":7002"},
DialOptions: []redis.DialOption{redis.DialConnectTimeout(5 * time.Second)},
CreatePool: createPool,
}
defer cluster.Close()
// initialize its mapping
if err := cluster.Refresh(); err != nil {
log.Fatalf("Refresh failed: %v", err)
}
// create a script that takes 2 keys and 2 values, and returns 1
var script = redis.NewScript(2, `
redis.call("SET", KEYS[1], ARGV[1])
redis.call("SET", KEYS[2], ARGV[2])
return 1
`)
// get a connection from the cluster
conn := cluster.Get()
defer conn.Close()
// bind it to the right node for the required keys, ahead of time
if err := redisc.BindConn(conn, "scr{a}1", "src{a}2"); err != nil {
log.Fatalf("BindConn failed: %v", err)
}
// script.Do, sends the whole script on first use
v, err := script.Do(conn, "scr{a}1", "scr{a}2", "x", "y")
if err != nil {
log.Fatalf("script.Do failed: %v", err)
}
fmt.Println("Do returned ", v)
// it is also possible to send only the hash, once it has been
// loaded on that node
if err := script.SendHash(conn, "scr{a}1", "scr{a}2", "x", "y"); err != nil {
log.Fatalf("script.SendHash failed: %v", err)
}
if err := conn.Flush(); err != nil {
log.Fatalf("Flush failed: %v", err)
}
// and receive the script's result
v, err = conn.Receive()
if err != nil {
log.Fatalf("Receive failed: %v", err)
}
fmt.Println("Receive returned ", v)
}
// Automatically retry in case of redirection errors.
func ExampleRetryConn() {
// create the cluster
cluster := redisc.Cluster{
StartupNodes: []string{":7000", ":7001", ":7002"},
DialOptions: []redis.DialOption{redis.DialConnectTimeout(5 * time.Second)},
CreatePool: createPool,
}
defer cluster.Close()
// initialize its mapping
if err := cluster.Refresh(); err != nil {
log.Fatalf("Refresh failed: %v", err)
}
// get a connection from the cluster
conn := cluster.Get()
defer conn.Close()
// create the retry connection - only Do, Close and Err are
// supported on that connection. It will make up to 3 attempts
// to get a valid response, and will wait 100ms before a retry
// in case of a TRYAGAIN redis error.
retryConn, err := redisc.RetryConn(conn, 3, 100*time.Millisecond)
if err != nil {
log.Fatalf("RetryConn failed: %v", err)
}
// call commands
v, err := retryConn.Do("GET", "key")
if err != nil {
log.Fatalf("GET failed: %v", err)
}
fmt.Println("GET returned ", v)
}
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