Go commons pool是一個通用的go語言對象池，基于Java版本的Apache Commons Pool改寫。Go commons pool實現了Java版本的主要功能，改寫了大多數Java版本的測試用例，測試覆蓋率達到90%，性能測試結果和Java版本的相近，已經可以用于生產環境，于是發布1.0版本。

Go commons pool保留了Java版本的主要功能，包括：

1. 自定義的 PooledObjectFactory.
2. 豐富的設置選項,可以精確控制對象的生命周期。詳細參看ObjectPoolConfig。
   • 對象池是否是 LIFO (后進先出) 或者是 FIFO (先進先出)
   • 對象池的容量控制
   • 對象池對象的驗證配置
   • 獲取對象時是否阻塞以及最大等待時間配置
   • 對象池對象的回收機制配置（支持后臺定時任務檢測回收）
   • 對象池對象的拋棄機制配置（主要用于防止對象池對象借出后未歸還，導致對象泄露）

但不包含以下Apache commons pool的功能：

1. KeyedObjectPool 實現
2. ProxiedObjectPool 實現
3. 對象池的統計功能

Go commons pool 最主要的應用場景是各種連接池，當前Go下的各種緩存或數據庫（比如redis/memcached）都自己實現了一個功能不太完備的連接池（比如缺少超時設置等），如果通過Go commons pool可以支持更豐富的設置。

Pool Configuration Option

Configuration option table, more detail description see ObjectPoolConfig

Usage

//use create func
pool := NewObjectPoolWithDefaultConfig(NewPooledObjectFactorySimple(
        func() (interface{}, error) {
            return &MyPoolObject{}, nil
        }))
obj, _ := pool.BorrowObject()
pool.ReturnObject(obj)

//use custom Object factory

type MyObjectFactory struct {

}

func (this *MyObjectFactory) MakeObject() (*PooledObject, error) {
    return NewPooledObject(&MyPoolObject{}), nil
}

func (this *MyObjectFactory) DestroyObject(object *PooledObject) error {
    //do destroy
    return nil
}

func (this *MyObjectFactory) ValidateObject(object *PooledObject) bool {
    //do validate
    return true
}

func (this *MyObjectFactory) ActivateObject(object *PooledObject) error {
    //do activate
    return nil
}

func (this *MyObjectFactory) PassivateObject(object *PooledObject) error {
    //do passivate
    return nil
}

pool := NewObjectPoolWithDefaultConfig(new(MyObjectFactory))
pool.Config.MaxTotal = 100
obj, _ := pool.BorrowObject()
pool.ReturnObject(obj)

more example please see pool_test.go and example_test.go

Note

PooledObjectFactory.MakeObject must return a pointer, not value. The following code will complain error.

pool := NewObjectPoolWithDefaultConfig(NewPooledObjectFactorySimple(
    func() (interface{}, error) {
        return "hello", nil
    }))
obj, _ := pool.BorrowObject()
pool.ReturnObject(obj)

The right way is:

pool := NewObjectPoolWithDefaultConfig(NewPooledObjectFactorySimple(
    func() (interface{}, error) {
        var stringPointer = new(string)
        *stringPointer = "hello"
        return stringPointer, nil
    }))

more example please see example_test.go

Dependency

• testify for test

PerformanceTest

The results of running the pool_perf_test is almost equal to the java version PerformanceTest

go test --perf=true

For Apache commons pool user

• Direct use pool.Config.xxx to change pool config
• Default config value is same as java version
• If TimeBetweenEvictionRunsMillis changed after ObjectPool created, should call ObjectPool.StartEvictor to take effect. Java version do this on set method.
• No KeyedObjectPool
• No ProxiedObjectPool
• No pool stats (TODO)

FAQ

FAQ

How to contribute

• Choose one open issue you want to solve, if not create one and describe what you want to change.
• Fork the repository on GitHub.
• Write code to solve the issue.
• Create PR and link to the issue.
• Make sure test and coverage pass.
• Wait maintainers to merge.

中文文檔

• Go Commons Pool發布以及Golang多線程編程問題總結
• Go Commons Pool 1.0 發布

License

Go Commons Pool is available under the Apache License, Version 2.0.

項目地址： https://github.com/jolestar/go-commons-pool