package redis import ( "fmt" "time" "github.com/garyburd/redigo/redis" ) // Redis is a cache backend. type Redis struct { pool *redis.Pool prefix string } // New Redis backend. func New(address string, db int, prefix string) (*Redis, error) { r := &Redis{ prefix: prefix, pool: &redis.Pool{ MaxIdle: 3, IdleTimeout: 240 * time.Second, Dial: func() (redis.Conn, error) { return redis.Dial("tcp", address, redis.DialConnectTimeout(10*time.Second), redis.DialDatabase(db), redis.DialKeepAlive(30*time.Second), ) }, }, } return r, nil } // Get a key from Redis. func (r *Redis) Get(key string) ([]byte, error) { conn := r.pool.Get() n, err := redis.Bytes(conn.Do("GET", r.prefix+key)) if err != nil { return nil, fmt.Errorf("Redis SET error: %s (conn error: %s)", err, conn.Err()) } return n, err } // Set a key in Redis. func (r *Redis) Set(key string, v []byte, expires int) error { conn := r.pool.Get() _, err := conn.Do("SETEX", r.prefix+key, expires, v) if err != nil { return fmt.Errorf("Redis SET error: %s (conn error: %s)", err, conn.Err()) } return nil } // Delete keys from Redis. func (r *Redis) Delete(key ...string) { conn := r.pool.Get() for _, v := range key { conn.Send("DEL", v) } conn.Flush() conn.Receive() } // Keys returns a list of Redis keys matching a pattern. func (r *Redis) Keys(pattern string) ([]string, error) { conn := r.pool.Get() n, err := redis.Strings(conn.Do("KEYS", pattern)) return n, err } // Lock a mutex. func (r *Redis) Lock(key, value string, expires int) bool { conn := r.pool.Get() n, err := redis.Int(conn.Do("SETNX", r.prefix+key, value)) return err == nil && n == 1 } // Unlock a mutex. func (r *Redis) Unlock(key string) { r.Delete(key) }