diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/garyburd/redigo/redis/pool.go')
-rw-r--r-- | Godeps/_workspace/src/github.com/garyburd/redigo/redis/pool.go | 393 |
1 files changed, 0 insertions, 393 deletions
diff --git a/Godeps/_workspace/src/github.com/garyburd/redigo/redis/pool.go b/Godeps/_workspace/src/github.com/garyburd/redigo/redis/pool.go deleted file mode 100644 index d66ef84b6..000000000 --- a/Godeps/_workspace/src/github.com/garyburd/redigo/redis/pool.go +++ /dev/null @@ -1,393 +0,0 @@ -// Copyright 2012 Gary Burd -// -// Licensed under the Apache License, Version 2.0 (the "License"): you may -// not use this file except in compliance with the License. You may obtain -// a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT -// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the -// License for the specific language governing permissions and limitations -// under the License. - -package redis - -import ( - "bytes" - "container/list" - "crypto/rand" - "crypto/sha1" - "errors" - "io" - "strconv" - "sync" - "time" - - "github.com/garyburd/redigo/internal" -) - -var nowFunc = time.Now // for testing - -// ErrPoolExhausted is returned from a pool connection method (Do, Send, -// Receive, Flush, Err) when the maximum number of database connections in the -// pool has been reached. -var ErrPoolExhausted = errors.New("redigo: connection pool exhausted") - -var ( - errPoolClosed = errors.New("redigo: connection pool closed") - errConnClosed = errors.New("redigo: connection closed") -) - -// Pool maintains a pool of connections. The application calls the Get method -// to get a connection from the pool and the connection's Close method to -// return the connection's resources to the pool. -// -// The following example shows how to use a pool in a web application. The -// application creates a pool at application startup and makes it available to -// request handlers using a global variable. -// -// func newPool(server, password string) *redis.Pool { -// return &redis.Pool{ -// MaxIdle: 3, -// IdleTimeout: 240 * time.Second, -// Dial: func () (redis.Conn, error) { -// c, err := redis.Dial("tcp", server) -// if err != nil { -// return nil, err -// } -// if _, err := c.Do("AUTH", password); err != nil { -// c.Close() -// return nil, err -// } -// return c, err -// }, -// TestOnBorrow: func(c redis.Conn, t time.Time) error { -// _, err := c.Do("PING") -// return err -// }, -// } -// } -// -// var ( -// pool *redis.Pool -// redisServer = flag.String("redisServer", ":6379", "") -// redisPassword = flag.String("redisPassword", "", "") -// ) -// -// func main() { -// flag.Parse() -// pool = newPool(*redisServer, *redisPassword) -// ... -// } -// -// A request handler gets a connection from the pool and closes the connection -// when the handler is done: -// -// func serveHome(w http.ResponseWriter, r *http.Request) { -// conn := pool.Get() -// defer conn.Close() -// .... -// } -// -type Pool struct { - - // Dial is an application supplied function for creating and configuring a - // connection. - // - // The connection returned from Dial must not be in a special state - // (subscribed to pubsub channel, transaction started, ...). - Dial func() (Conn, error) - - // TestOnBorrow is an optional application supplied function for checking - // the health of an idle connection before the connection is used again by - // the application. Argument t is the time that the connection was returned - // to the pool. If the function returns an error, then the connection is - // closed. - TestOnBorrow func(c Conn, t time.Time) error - - // Maximum number of idle connections in the pool. - MaxIdle int - - // Maximum number of connections allocated by the pool at a given time. - // When zero, there is no limit on the number of connections in the pool. - MaxActive int - - // Close connections after remaining idle for this duration. If the value - // is zero, then idle connections are not closed. Applications should set - // the timeout to a value less than the server's timeout. - IdleTimeout time.Duration - - // If Wait is true and the pool is at the MaxActive limit, then Get() waits - // for a connection to be returned to the pool before returning. - Wait bool - - // mu protects fields defined below. - mu sync.Mutex - cond *sync.Cond - closed bool - active int - - // Stack of idleConn with most recently used at the front. - idle list.List -} - -type idleConn struct { - c Conn - t time.Time -} - -// NewPool creates a new pool. -// -// Deprecated: Initialize the Pool directory as shown in the example. -func NewPool(newFn func() (Conn, error), maxIdle int) *Pool { - return &Pool{Dial: newFn, MaxIdle: maxIdle} -} - -// Get gets a connection. The application must close the returned connection. -// This method always returns a valid connection so that applications can defer -// error handling to the first use of the connection. If there is an error -// getting an underlying connection, then the connection Err, Do, Send, Flush -// and Receive methods return that error. -func (p *Pool) Get() Conn { - c, err := p.get() - if err != nil { - return errorConnection{err} - } - return &pooledConnection{p: p, c: c} -} - -// ActiveCount returns the number of active connections in the pool. -func (p *Pool) ActiveCount() int { - p.mu.Lock() - active := p.active - p.mu.Unlock() - return active -} - -// Close releases the resources used by the pool. -func (p *Pool) Close() error { - p.mu.Lock() - idle := p.idle - p.idle.Init() - p.closed = true - p.active -= idle.Len() - if p.cond != nil { - p.cond.Broadcast() - } - p.mu.Unlock() - for e := idle.Front(); e != nil; e = e.Next() { - e.Value.(idleConn).c.Close() - } - return nil -} - -// release decrements the active count and signals waiters. The caller must -// hold p.mu during the call. -func (p *Pool) release() { - p.active -= 1 - if p.cond != nil { - p.cond.Signal() - } -} - -// get prunes stale connections and returns a connection from the idle list or -// creates a new connection. -func (p *Pool) get() (Conn, error) { - p.mu.Lock() - - // Prune stale connections. - - if timeout := p.IdleTimeout; timeout > 0 { - for i, n := 0, p.idle.Len(); i < n; i++ { - e := p.idle.Back() - if e == nil { - break - } - ic := e.Value.(idleConn) - if ic.t.Add(timeout).After(nowFunc()) { - break - } - p.idle.Remove(e) - p.release() - p.mu.Unlock() - ic.c.Close() - p.mu.Lock() - } - } - - for { - - // Get idle connection. - - for i, n := 0, p.idle.Len(); i < n; i++ { - e := p.idle.Front() - if e == nil { - break - } - ic := e.Value.(idleConn) - p.idle.Remove(e) - test := p.TestOnBorrow - p.mu.Unlock() - if test == nil || test(ic.c, ic.t) == nil { - return ic.c, nil - } - ic.c.Close() - p.mu.Lock() - p.release() - } - - // Check for pool closed before dialing a new connection. - - if p.closed { - p.mu.Unlock() - return nil, errors.New("redigo: get on closed pool") - } - - // Dial new connection if under limit. - - if p.MaxActive == 0 || p.active < p.MaxActive { - dial := p.Dial - p.active += 1 - p.mu.Unlock() - c, err := dial() - if err != nil { - p.mu.Lock() - p.release() - p.mu.Unlock() - c = nil - } - return c, err - } - - if !p.Wait { - p.mu.Unlock() - return nil, ErrPoolExhausted - } - - if p.cond == nil { - p.cond = sync.NewCond(&p.mu) - } - p.cond.Wait() - } -} - -func (p *Pool) put(c Conn, forceClose bool) error { - err := c.Err() - p.mu.Lock() - if !p.closed && err == nil && !forceClose { - p.idle.PushFront(idleConn{t: nowFunc(), c: c}) - if p.idle.Len() > p.MaxIdle { - c = p.idle.Remove(p.idle.Back()).(idleConn).c - } else { - c = nil - } - } - - if c == nil { - if p.cond != nil { - p.cond.Signal() - } - p.mu.Unlock() - return nil - } - - p.release() - p.mu.Unlock() - return c.Close() -} - -type pooledConnection struct { - p *Pool - c Conn - state int -} - -var ( - sentinel []byte - sentinelOnce sync.Once -) - -func initSentinel() { - p := make([]byte, 64) - if _, err := rand.Read(p); err == nil { - sentinel = p - } else { - h := sha1.New() - io.WriteString(h, "Oops, rand failed. Use time instead.") - io.WriteString(h, strconv.FormatInt(time.Now().UnixNano(), 10)) - sentinel = h.Sum(nil) - } -} - -func (pc *pooledConnection) Close() error { - c := pc.c - if _, ok := c.(errorConnection); ok { - return nil - } - pc.c = errorConnection{errConnClosed} - - if pc.state&internal.MultiState != 0 { - c.Send("DISCARD") - pc.state &^= (internal.MultiState | internal.WatchState) - } else if pc.state&internal.WatchState != 0 { - c.Send("UNWATCH") - pc.state &^= internal.WatchState - } - if pc.state&internal.SubscribeState != 0 { - c.Send("UNSUBSCRIBE") - c.Send("PUNSUBSCRIBE") - // To detect the end of the message stream, ask the server to echo - // a sentinel value and read until we see that value. - sentinelOnce.Do(initSentinel) - c.Send("ECHO", sentinel) - c.Flush() - for { - p, err := c.Receive() - if err != nil { - break - } - if p, ok := p.([]byte); ok && bytes.Equal(p, sentinel) { - pc.state &^= internal.SubscribeState - break - } - } - } - c.Do("") - pc.p.put(c, pc.state != 0) - return nil -} - -func (pc *pooledConnection) Err() error { - return pc.c.Err() -} - -func (pc *pooledConnection) Do(commandName string, args ...interface{}) (reply interface{}, err error) { - ci := internal.LookupCommandInfo(commandName) - pc.state = (pc.state | ci.Set) &^ ci.Clear - return pc.c.Do(commandName, args...) -} - -func (pc *pooledConnection) Send(commandName string, args ...interface{}) error { - ci := internal.LookupCommandInfo(commandName) - pc.state = (pc.state | ci.Set) &^ ci.Clear - return pc.c.Send(commandName, args...) -} - -func (pc *pooledConnection) Flush() error { - return pc.c.Flush() -} - -func (pc *pooledConnection) Receive() (reply interface{}, err error) { - return pc.c.Receive() -} - -type errorConnection struct{ err error } - -func (ec errorConnection) Do(string, ...interface{}) (interface{}, error) { return nil, ec.err } -func (ec errorConnection) Send(string, ...interface{}) error { return ec.err } -func (ec errorConnection) Err() error { return ec.err } -func (ec errorConnection) Close() error { return ec.err } -func (ec errorConnection) Flush() error { return ec.err } -func (ec errorConnection) Receive() (interface{}, error) { return nil, ec.err } |