内容压缩算法使用Pool管理

internal/compressions/writer_pool.go

@@ -0,0 +1,61 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package compressions
+
+import (
+	"io"
+)
+
+type WriterPool struct {
+	m       map[int]chan Writer // level => chan Writer
+	newFunc func(writer io.Writer, level int) (Writer, error)
+}
+
+func NewWriterPool(maxSize int, maxLevel int, newFunc func(writer io.Writer, level int) (Writer, error)) *WriterPool {
+	if maxSize <= 0 {
+		maxSize = 1024
+	}
+
+	var m = map[int]chan Writer{}
+	for i := 0; i <= maxLevel; i++ {
+		m[i] = make(chan Writer, maxSize)
+	}
+
+	return &WriterPool{
+		m:       m,
+		newFunc: newFunc,
+	}
+}
+
+func (this *WriterPool) Get(parentWriter io.Writer, level int) (Writer, error) {
+	c, ok := this.m[level]
+	if !ok {
+		c = this.m[0]
+	}
+
+	select {
+	case writer := <-c:
+		writer.Reset(parentWriter)
+		writer.ResetFinish()
+		return writer, nil
+	default:
+		writer, err := this.newFunc(parentWriter, level)
+		if err != nil {
+			return nil, err
+		}
+		writer.SetPool(this)
+		return writer, nil
+	}
+}
+
+func (this *WriterPool) Put(writer Writer) {
+	var level = writer.Level()
+	c, ok := this.m[level]
+	if !ok {
+		c = this.m[0]
+	}
+	select {
+	case c <- writer:
+	default:
+	}
+}