initial

src/server/torr/storage/memcache/Buffer.go

@@ -0,0 +1,86 @@
+package memcache
+
+import (
+	"fmt"
+	"sync"
+
+	"server/utils"
+)
+
+type buffer struct {
+	pieceId int
+	buf     []byte
+	used    bool
+}
+
+type BufferPool struct {
+	buffs map[int]*buffer
+	frees int
+	size  int64
+	mu    sync.Mutex
+}
+
+func NewBufferPool(bufferLength int64, capacity int64) *BufferPool {
+	bp := new(BufferPool)
+	buffsSize := int(capacity/bufferLength) + 3
+	bp.frees = buffsSize
+	bp.size = bufferLength
+	return bp
+}
+
+func (b *BufferPool) mkBuffs() {
+	if b.buffs != nil {
+		return
+	}
+	b.buffs = make(map[int]*buffer, b.frees)
+	fmt.Println("Create", b.frees, "buffers")
+	for i := 0; i < b.frees; i++ {
+		buf := buffer{
+			-1,
+			make([]byte, b.size),
+			false,
+		}
+		b.buffs[i] = &buf
+	}
+}
+
+func (b *BufferPool) GetBuffer(p *Piece) (buff []byte, index int) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.mkBuffs()
+	for id, buf := range b.buffs {
+		if !buf.used {
+			buf.used = true
+			buf.pieceId = p.Id
+			buff = buf.buf
+			index = id
+			b.frees--
+			//fmt.Printf("Get buffer: %v %v %v %p\n", id, p.Id, b.frees, buff)
+			return
+		}
+	}
+	fmt.Println("Create slow buffer")
+	return make([]byte, b.size), -1
+}
+
+func (b *BufferPool) ReleaseBuffer(index int) {
+	if index == -1 {
+		utils.FreeOSMem()
+		return
+	}
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.mkBuffs()
+	if buff, ok := b.buffs[index]; ok {
+		buff.used = false
+		buff.pieceId = -1
+		b.frees++
+		//fmt.Println("Release buffer:", index, b.frees)
+	} else {
+		utils.FreeOSMem()
+	}
+}
+
+func (b *BufferPool) Len() int {
+	return b.frees
+}