78 lines
1.5 KiB
Go
78 lines
1.5 KiB
Go
package common
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import (
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"errors"
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"io"
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"log"
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"sync"
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)
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//一个安全的资源池，被管理的资源必须都实现io.Close接口
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type Pool struct {
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m sync.Mutex
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res chan io.Closer
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factory func() (io.Closer, error)
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closed bool
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}
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var ErrPoolClosed = errors.New("资源池已经被关闭。")
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//创建一个资源池
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func NewPool(fn func() (io.Closer, error), size uint) (*Pool, error) {
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if size <= 0 {
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return nil, errors.New("size的值太小了。")
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}
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return &Pool{
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factory: fn,
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res: make(chan io.Closer, size),
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}, nil
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}
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//从资源池里获取一个资源
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func (p *Pool) Acquire() (io.Closer, error) {
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select {
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case r, ok := <-p.res:
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log.Println("Acquire:共享资源")
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if !ok {
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return nil, ErrPoolClosed
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}
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return r, nil
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default:
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log.Println("Acquire:新生成资源")
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return p.factory()
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}
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}
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//关闭资源池，释放资源
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func (p *Pool) Close() {
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p.m.Lock()
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defer p.m.Unlock()
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if p.closed {
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return
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}
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p.closed = true
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//关闭通道，不让写入了
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close(p.res)
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//关闭通道里的资源
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for r := range p.res {
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r.Close()
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}
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}
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func (p *Pool) Release(r io.Closer) {
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//保证该操作和Close方法的操作是安全的
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p.m.Lock()
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defer p.m.Unlock()
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//资源池都关闭了，就省这一个没有释放的资源了，释放即可
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if p.closed {
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r.Close()
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return
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}
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select {
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case p.res <- r:
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log.Println("资源释放到池子里了")
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default:
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log.Println("资源池满了，释放这个资源吧")
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r.Close()
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}
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}
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