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Diffstat (limited to 'src/dma/vendor/github.com/valyala/bytebufferpool')
6 files changed, 327 insertions, 0 deletions
diff --git a/src/dma/vendor/github.com/valyala/bytebufferpool/.travis.yml b/src/dma/vendor/github.com/valyala/bytebufferpool/.travis.yml new file mode 100644 index 00000000..6a6ec2eb --- /dev/null +++ b/src/dma/vendor/github.com/valyala/bytebufferpool/.travis.yml @@ -0,0 +1,15 @@ +language: go + +go: + - 1.6 + +script: + # build test for supported platforms + - GOOS=linux go build + - GOOS=darwin go build + - GOOS=freebsd go build + - GOOS=windows go build + - GOARCH=386 go build + + # run tests on a standard platform + - go test -v ./... diff --git a/src/dma/vendor/github.com/valyala/bytebufferpool/LICENSE b/src/dma/vendor/github.com/valyala/bytebufferpool/LICENSE new file mode 100644 index 00000000..f7c935c2 --- /dev/null +++ b/src/dma/vendor/github.com/valyala/bytebufferpool/LICENSE @@ -0,0 +1,22 @@ +The MIT License (MIT) + +Copyright (c) 2016 Aliaksandr Valialkin, VertaMedia + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. + diff --git a/src/dma/vendor/github.com/valyala/bytebufferpool/README.md b/src/dma/vendor/github.com/valyala/bytebufferpool/README.md new file mode 100644 index 00000000..061357e8 --- /dev/null +++ b/src/dma/vendor/github.com/valyala/bytebufferpool/README.md @@ -0,0 +1,21 @@ +[](https://travis-ci.org/valyala/bytebufferpool) +[](http://godoc.org/github.com/valyala/bytebufferpool) +[](http://goreportcard.com/report/valyala/bytebufferpool) + +# bytebufferpool + +An implementation of a pool of byte buffers with anti-memory-waste protection. + +The pool may waste limited amount of memory due to fragmentation. +This amount equals to the maximum total size of the byte buffers +in concurrent use. + +# Benchmark results +Currently bytebufferpool is fastest and most effective buffer pool written in Go. + +You can find results [here](https://omgnull.github.io/go-benchmark/buffer/). + +# bytebufferpool users + +* [fasthttp](https://github.com/valyala/fasthttp) +* [quicktemplate](https://github.com/valyala/quicktemplate) diff --git a/src/dma/vendor/github.com/valyala/bytebufferpool/bytebuffer.go b/src/dma/vendor/github.com/valyala/bytebufferpool/bytebuffer.go new file mode 100644 index 00000000..07a055a2 --- /dev/null +++ b/src/dma/vendor/github.com/valyala/bytebufferpool/bytebuffer.go @@ -0,0 +1,111 @@ +package bytebufferpool + +import "io" + +// ByteBuffer provides byte buffer, which can be used for minimizing +// memory allocations. +// +// ByteBuffer may be used with functions appending data to the given []byte +// slice. See example code for details. +// +// Use Get for obtaining an empty byte buffer. +type ByteBuffer struct { + + // B is a byte buffer to use in append-like workloads. + // See example code for details. + B []byte +} + +// Len returns the size of the byte buffer. +func (b *ByteBuffer) Len() int { + return len(b.B) +} + +// ReadFrom implements io.ReaderFrom. +// +// The function appends all the data read from r to b. +func (b *ByteBuffer) ReadFrom(r io.Reader) (int64, error) { + p := b.B + nStart := int64(len(p)) + nMax := int64(cap(p)) + n := nStart + if nMax == 0 { + nMax = 64 + p = make([]byte, nMax) + } else { + p = p[:nMax] + } + for { + if n == nMax { + nMax *= 2 + bNew := make([]byte, nMax) + copy(bNew, p) + p = bNew + } + nn, err := r.Read(p[n:]) + n += int64(nn) + if err != nil { + b.B = p[:n] + n -= nStart + if err == io.EOF { + return n, nil + } + return n, err + } + } +} + +// WriteTo implements io.WriterTo. +func (b *ByteBuffer) WriteTo(w io.Writer) (int64, error) { + n, err := w.Write(b.B) + return int64(n), err +} + +// Bytes returns b.B, i.e. all the bytes accumulated in the buffer. +// +// The purpose of this function is bytes.Buffer compatibility. +func (b *ByteBuffer) Bytes() []byte { + return b.B +} + +// Write implements io.Writer - it appends p to ByteBuffer.B +func (b *ByteBuffer) Write(p []byte) (int, error) { + b.B = append(b.B, p...) + return len(p), nil +} + +// WriteByte appends the byte c to the buffer. +// +// The purpose of this function is bytes.Buffer compatibility. +// +// The function always returns nil. +func (b *ByteBuffer) WriteByte(c byte) error { + b.B = append(b.B, c) + return nil +} + +// WriteString appends s to ByteBuffer.B. +func (b *ByteBuffer) WriteString(s string) (int, error) { + b.B = append(b.B, s...) + return len(s), nil +} + +// Set sets ByteBuffer.B to p. +func (b *ByteBuffer) Set(p []byte) { + b.B = append(b.B[:0], p...) +} + +// SetString sets ByteBuffer.B to s. +func (b *ByteBuffer) SetString(s string) { + b.B = append(b.B[:0], s...) +} + +// String returns string representation of ByteBuffer.B. +func (b *ByteBuffer) String() string { + return string(b.B) +} + +// Reset makes ByteBuffer.B empty. +func (b *ByteBuffer) Reset() { + b.B = b.B[:0] +} diff --git a/src/dma/vendor/github.com/valyala/bytebufferpool/doc.go b/src/dma/vendor/github.com/valyala/bytebufferpool/doc.go new file mode 100644 index 00000000..e511b7c5 --- /dev/null +++ b/src/dma/vendor/github.com/valyala/bytebufferpool/doc.go @@ -0,0 +1,7 @@ +// Package bytebufferpool implements a pool of byte buffers +// with anti-fragmentation protection. +// +// The pool may waste limited amount of memory due to fragmentation. +// This amount equals to the maximum total size of the byte buffers +// in concurrent use. +package bytebufferpool diff --git a/src/dma/vendor/github.com/valyala/bytebufferpool/pool.go b/src/dma/vendor/github.com/valyala/bytebufferpool/pool.go new file mode 100644 index 00000000..8bb4134d --- /dev/null +++ b/src/dma/vendor/github.com/valyala/bytebufferpool/pool.go @@ -0,0 +1,151 @@ +package bytebufferpool + +import ( + "sort" + "sync" + "sync/atomic" +) + +const ( + minBitSize = 6 // 2**6=64 is a CPU cache line size + steps = 20 + + minSize = 1 << minBitSize + maxSize = 1 << (minBitSize + steps - 1) + + calibrateCallsThreshold = 42000 + maxPercentile = 0.95 +) + +// Pool represents byte buffer pool. +// +// Distinct pools may be used for distinct types of byte buffers. +// Properly determined byte buffer types with their own pools may help reducing +// memory waste. +type Pool struct { + calls [steps]uint64 + calibrating uint64 + + defaultSize uint64 + maxSize uint64 + + pool sync.Pool +} + +var defaultPool Pool + +// Get returns an empty byte buffer from the pool. +// +// Got byte buffer may be returned to the pool via Put call. +// This reduces the number of memory allocations required for byte buffer +// management. +func Get() *ByteBuffer { return defaultPool.Get() } + +// Get returns new byte buffer with zero length. +// +// The byte buffer may be returned to the pool via Put after the use +// in order to minimize GC overhead. +func (p *Pool) Get() *ByteBuffer { + v := p.pool.Get() + if v != nil { + return v.(*ByteBuffer) + } + return &ByteBuffer{ + B: make([]byte, 0, atomic.LoadUint64(&p.defaultSize)), + } +} + +// Put returns byte buffer to the pool. +// +// ByteBuffer.B mustn't be touched after returning it to the pool. +// Otherwise data races will occur. +func Put(b *ByteBuffer) { defaultPool.Put(b) } + +// Put releases byte buffer obtained via Get to the pool. +// +// The buffer mustn't be accessed after returning to the pool. +func (p *Pool) Put(b *ByteBuffer) { + idx := index(len(b.B)) + + if atomic.AddUint64(&p.calls[idx], 1) > calibrateCallsThreshold { + p.calibrate() + } + + maxSize := int(atomic.LoadUint64(&p.maxSize)) + if maxSize == 0 || cap(b.B) <= maxSize { + b.Reset() + p.pool.Put(b) + } +} + +func (p *Pool) calibrate() { + if !atomic.CompareAndSwapUint64(&p.calibrating, 0, 1) { + return + } + + a := make(callSizes, 0, steps) + var callsSum uint64 + for i := uint64(0); i < steps; i++ { + calls := atomic.SwapUint64(&p.calls[i], 0) + callsSum += calls + a = append(a, callSize{ + calls: calls, + size: minSize << i, + }) + } + sort.Sort(a) + + defaultSize := a[0].size + maxSize := defaultSize + + maxSum := uint64(float64(callsSum) * maxPercentile) + callsSum = 0 + for i := 0; i < steps; i++ { + if callsSum > maxSum { + break + } + callsSum += a[i].calls + size := a[i].size + if size > maxSize { + maxSize = size + } + } + + atomic.StoreUint64(&p.defaultSize, defaultSize) + atomic.StoreUint64(&p.maxSize, maxSize) + + atomic.StoreUint64(&p.calibrating, 0) +} + +type callSize struct { + calls uint64 + size uint64 +} + +type callSizes []callSize + +func (ci callSizes) Len() int { + return len(ci) +} + +func (ci callSizes) Less(i, j int) bool { + return ci[i].calls > ci[j].calls +} + +func (ci callSizes) Swap(i, j int) { + ci[i], ci[j] = ci[j], ci[i] +} + +func index(n int) int { + n-- + n >>= minBitSize + idx := 0 + for n > 0 { + n >>= 1 + idx++ + } + if idx >= steps { + idx = steps - 1 + } + return idx +} |