mirror of
https://github.com/v2fly/v2ray-core.git
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133 lines
2.8 KiB
Go
133 lines
2.8 KiB
Go
package alloc
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import (
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"sync"
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)
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// Buffer is a recyclable allocation of a byte array. Buffer.Release() recycles
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// the buffer into an internal buffer pool, in order to recreate a buffer more
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// quickly.
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type Buffer struct {
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head []byte
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pool *bufferPool
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Value []byte
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}
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// Release recycles the buffer into an internal buffer pool.
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func (b *Buffer) Release() {
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b.pool.free(b)
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b.head = nil
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b.Value = nil
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b.pool = nil
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}
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// Clear clears the content of the buffer, results an empty buffer with
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// Len() = 0.
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func (b *Buffer) Clear() *Buffer {
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b.Value = b.head[:0]
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return b
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}
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// AppendBytes appends one or more bytes to the end of the buffer.
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func (b *Buffer) AppendBytes(bytes ...byte) *Buffer {
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b.Value = append(b.Value, bytes...)
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return b
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}
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// Append appends a byte array to the end of the buffer.
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func (b *Buffer) Append(data []byte) *Buffer {
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b.Value = append(b.Value, data...)
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return b
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}
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func (b *Buffer) Bytes() []byte {
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return b.Value
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}
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// Slice cuts the buffer at the given position.
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func (b *Buffer) Slice(from, to int) *Buffer {
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b.Value = b.Value[from:to]
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return b
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}
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// SliceFrom cuts the buffer at the given position.
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func (b *Buffer) SliceFrom(from int) *Buffer {
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b.Value = b.Value[from:]
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return b
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}
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// Len returns the length of the buffer content.
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func (b *Buffer) Len() int {
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return len(b.Value)
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}
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// IsFull returns true if the buffer has no more room to grow.
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func (b *Buffer) IsFull() bool {
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return len(b.Value) == cap(b.Value)
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}
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// Write implements Write method in io.Writer.
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func (b *Buffer) Write(data []byte) (int, error) {
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b.Append(data)
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return len(data), nil
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}
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type bufferPool struct {
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chain chan []byte
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allocator *sync.Pool
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}
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func newBufferPool(bufferSize, poolSize int) *bufferPool {
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pool := &bufferPool{
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chain: make(chan []byte, poolSize),
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allocator: &sync.Pool{
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New: func() interface{} { return make([]byte, bufferSize) },
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},
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}
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for i := 0; i < poolSize; i++ {
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pool.chain <- make([]byte, bufferSize)
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}
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return pool
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}
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func (p *bufferPool) allocate() *Buffer {
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var b []byte
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select {
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case b = <-p.chain:
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default:
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b = p.allocator.Get().([]byte)
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}
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return &Buffer{
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head: b,
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pool: p,
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Value: b,
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}
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}
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func (p *bufferPool) free(buffer *Buffer) {
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select {
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case p.chain <- buffer.head:
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default:
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p.allocator.Put(buffer.head)
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}
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}
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var smallPool = newBufferPool(1024, 256)
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var mediumPool = newBufferPool(8*1024, 512)
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var largePool = newBufferPool(64*1024, 128)
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// NewSmallBuffer creates a Buffer with 1K bytes of arbitrary content.
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func NewSmallBuffer() *Buffer {
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return smallPool.allocate()
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}
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// NewBuffer creates a Buffer with 8K bytes of arbitrary content.
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func NewBuffer() *Buffer {
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return mediumPool.allocate()
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}
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// NewLargeBuffer creates a Buffer with 64K bytes of arbitrary content.
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func NewLargeBuffer() *Buffer {
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return largePool.allocate()
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}
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