60 lines
1.3 KiB
Go
60 lines
1.3 KiB
Go
// Copyright (C) 2016 The Protocol Authors.
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package protocol
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import "sync"
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type bufferPool struct {
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minSize int
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pool sync.Pool
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}
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// get returns a new buffer of the requested size
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func (p *bufferPool) get(size int) []byte {
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intf := p.pool.Get()
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if intf == nil {
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// Pool is empty, must allocate.
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return p.new(size)
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}
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bs := *intf.(*[]byte)
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if cap(bs) < size {
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// Buffer was too small, leave it for someone else and allocate.
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p.pool.Put(intf)
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return p.new(size)
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}
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return bs[:size]
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}
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// upgrade grows the buffer to the requested size, while attempting to reuse
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// it if possible.
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func (p *bufferPool) upgrade(bs []byte, size int) []byte {
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if cap(bs) >= size {
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// Reslicing is enough, lets go!
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return bs[:size]
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}
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// It was too small. But it pack into the pool and try to get another
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// buffer.
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p.put(bs)
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return p.get(size)
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}
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// put returns the buffer to the pool
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func (p *bufferPool) put(bs []byte) {
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p.pool.Put(&bs)
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}
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// new creates a new buffer of the requested size, taking the minimum
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// allocation count into account. For internal use only.
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func (p *bufferPool) new(size int) []byte {
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allocSize := size
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if allocSize < p.minSize {
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// Avoid allocating tiny buffers that we won't be able to reuse for
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// anything useful.
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allocSize = p.minSize
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}
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return make([]byte, allocSize)[:size]
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}
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