46 lines
1.1 KiB
Go
46 lines
1.1 KiB
Go
// Provides leaky buffer, based on the example in Effective Go.
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package shadowsocks
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type LeakyBuf struct {
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bufSize int // size of each buffer
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freeList chan []byte
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}
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const leakyBufSize = 4108 // data.len(2) + hmacsha1(10) + data(4096)
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const maxNBuf = 2048
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var leakyBuf = NewLeakyBuf(maxNBuf, leakyBufSize)
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// NewLeakyBuf creates a leaky buffer which can hold at most n buffer, each
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// with bufSize bytes.
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func NewLeakyBuf(n, bufSize int) *LeakyBuf {
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return &LeakyBuf{
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bufSize: bufSize,
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freeList: make(chan []byte, n),
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}
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}
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// Get returns a buffer from the leaky buffer or create a new buffer.
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func (lb *LeakyBuf) Get() (b []byte) {
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select {
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case b = <-lb.freeList:
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default:
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b = make([]byte, lb.bufSize)
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}
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return
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}
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// Put add the buffer into the free buffer pool for reuse. Panic if the buffer
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// size is not the same with the leaky buffer's. This is intended to expose
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// error usage of leaky buffer.
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func (lb *LeakyBuf) Put(b []byte) {
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if len(b) != lb.bufSize {
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panic("invalid buffer size that's put into leaky buffer")
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}
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select {
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case lb.freeList <- b:
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default:
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}
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return
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}
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