Update vendor

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.
+

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]
+}

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

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
+}

vendor/github.com/valyala/fasttemplate/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Aliaksandr Valialkin
+
+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.
+

vendor/github.com/valyala/fasttemplate/template.go

@@ -0,0 +1,317 @@
+// Package fasttemplate implements simple and fast template library.
+//
+// Fasttemplate is faster than text/template, strings.Replace
+// and strings.Replacer.
+//
+// Fasttemplate ideally fits for fast and simple placeholders' substitutions.
+package fasttemplate
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/valyala/bytebufferpool"
+	"io"
+)
+
+// ExecuteFunc calls f on each template tag (placeholder) occurrence.
+//
+// Returns the number of bytes written to w.
+//
+// This function is optimized for constantly changing templates.
+// Use Template.ExecuteFunc for frozen templates.
+func ExecuteFunc(template, startTag, endTag string, w io.Writer, f TagFunc) (int64, error) {
+	s := unsafeString2Bytes(template)
+	a := unsafeString2Bytes(startTag)
+	b := unsafeString2Bytes(endTag)
+
+	var nn int64
+	var ni int
+	var err error
+	for {
+		n := bytes.Index(s, a)
+		if n < 0 {
+			break
+		}
+		ni, err = w.Write(s[:n])
+		nn += int64(ni)
+		if err != nil {
+			return nn, err
+		}
+
+		s = s[n+len(a):]
+		n = bytes.Index(s, b)
+		if n < 0 {
+			// cannot find end tag - just write it to the output.
+			ni, _ = w.Write(a)
+			nn += int64(ni)
+			break
+		}
+
+		ni, err = f(w, unsafeBytes2String(s[:n]))
+		nn += int64(ni)
+		s = s[n+len(b):]
+	}
+	ni, err = w.Write(s)
+	nn += int64(ni)
+
+	return nn, err
+}
+
+// Execute substitutes template tags (placeholders) with the corresponding
+// values from the map m and writes the result to the given writer w.
+//
+// Substitution map m may contain values with the following types:
+//   * []byte - the fastest value type
+//   * string - convenient value type
+//   * TagFunc - flexible value type
+//
+// Returns the number of bytes written to w.
+//
+// This function is optimized for constantly changing templates.
+// Use Template.Execute for frozen templates.
+func Execute(template, startTag, endTag string, w io.Writer, m map[string]interface{}) (int64, error) {
+	return ExecuteFunc(template, startTag, endTag, w, func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) })
+}
+
+// ExecuteFuncString calls f on each template tag (placeholder) occurrence
+// and substitutes it with the data written to TagFunc's w.
+//
+// Returns the resulting string.
+//
+// This function is optimized for constantly changing templates.
+// Use Template.ExecuteFuncString for frozen templates.
+func ExecuteFuncString(template, startTag, endTag string, f TagFunc) string {
+	tagsCount := bytes.Count(unsafeString2Bytes(template), unsafeString2Bytes(startTag))
+	if tagsCount == 0 {
+		return template
+	}
+
+	bb := byteBufferPool.Get()
+	if _, err := ExecuteFunc(template, startTag, endTag, bb, f); err != nil {
+		panic(fmt.Sprintf("unexpected error: %s", err))
+	}
+	s := string(bb.B)
+	bb.Reset()
+	byteBufferPool.Put(bb)
+	return s
+}
+
+var byteBufferPool bytebufferpool.Pool
+
+// ExecuteString substitutes template tags (placeholders) with the corresponding
+// values from the map m and returns the result.
+//
+// Substitution map m may contain values with the following types:
+//   * []byte - the fastest value type
+//   * string - convenient value type
+//   * TagFunc - flexible value type
+//
+// This function is optimized for constantly changing templates.
+// Use Template.ExecuteString for frozen templates.
+func ExecuteString(template, startTag, endTag string, m map[string]interface{}) string {
+	return ExecuteFuncString(template, startTag, endTag, func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) })
+}
+
+// Template implements simple template engine, which can be used for fast
+// tags' (aka placeholders) substitution.
+type Template struct {
+	template string
+	startTag string
+	endTag   string
+
+	texts          [][]byte
+	tags           []string
+	byteBufferPool bytebufferpool.Pool
+}
+
+// New parses the given template using the given startTag and endTag
+// as tag start and tag end.
+//
+// The returned template can be executed by concurrently running goroutines
+// using Execute* methods.
+//
+// New panics if the given template cannot be parsed. Use NewTemplate instead
+// if template may contain errors.
+func New(template, startTag, endTag string) *Template {
+	t, err := NewTemplate(template, startTag, endTag)
+	if err != nil {
+		panic(err)
+	}
+	return t
+}
+
+// NewTemplate parses the given template using the given startTag and endTag
+// as tag start and tag end.
+//
+// The returned template can be executed by concurrently running goroutines
+// using Execute* methods.
+func NewTemplate(template, startTag, endTag string) (*Template, error) {
+	var t Template
+	err := t.Reset(template, startTag, endTag)
+	if err != nil {
+		return nil, err
+	}
+	return &t, nil
+}
+
+// TagFunc can be used as a substitution value in the map passed to Execute*.
+// Execute* functions pass tag (placeholder) name in 'tag' argument.
+//
+// TagFunc must be safe to call from concurrently running goroutines.
+//
+// TagFunc must write contents to w and return the number of bytes written.
+type TagFunc func(w io.Writer, tag string) (int, error)
+
+// Reset resets the template t to new one defined by
+// template, startTag and endTag.
+//
+// Reset allows Template object re-use.
+//
+// Reset may be called only if no other goroutines call t methods at the moment.
+func (t *Template) Reset(template, startTag, endTag string) error {
+	// Keep these vars in t, so GC won't collect them and won't break
+	// vars derived via unsafe*
+	t.template = template
+	t.startTag = startTag
+	t.endTag = endTag
+	t.texts = t.texts[:0]
+	t.tags = t.tags[:0]
+
+	if len(startTag) == 0 {
+		panic("startTag cannot be empty")
+	}
+	if len(endTag) == 0 {
+		panic("endTag cannot be empty")
+	}
+
+	s := unsafeString2Bytes(template)
+	a := unsafeString2Bytes(startTag)
+	b := unsafeString2Bytes(endTag)
+
+	tagsCount := bytes.Count(s, a)
+	if tagsCount == 0 {
+		return nil
+	}
+
+	if tagsCount+1 > cap(t.texts) {
+		t.texts = make([][]byte, 0, tagsCount+1)
+	}
+	if tagsCount > cap(t.tags) {
+		t.tags = make([]string, 0, tagsCount)
+	}
+
+	for {
+		n := bytes.Index(s, a)
+		if n < 0 {
+			t.texts = append(t.texts, s)
+			break
+		}
+		t.texts = append(t.texts, s[:n])
+
+		s = s[n+len(a):]
+		n = bytes.Index(s, b)
+		if n < 0 {
+			return fmt.Errorf("Cannot find end tag=%q in the template=%q starting from %q", endTag, template, s)
+		}
+
+		t.tags = append(t.tags, unsafeBytes2String(s[:n]))
+		s = s[n+len(b):]
+	}
+
+	return nil
+}
+
+// ExecuteFunc calls f on each template tag (placeholder) occurrence.
+//
+// Returns the number of bytes written to w.
+//
+// This function is optimized for frozen templates.
+// Use ExecuteFunc for constantly changing templates.
+func (t *Template) ExecuteFunc(w io.Writer, f TagFunc) (int64, error) {
+	var nn int64
+
+	n := len(t.texts) - 1
+	if n == -1 {
+		ni, err := w.Write(unsafeString2Bytes(t.template))
+		return int64(ni), err
+	}
+
+	for i := 0; i < n; i++ {
+		ni, err := w.Write(t.texts[i])
+		nn += int64(ni)
+		if err != nil {
+			return nn, err
+		}
+
+		ni, err = f(w, t.tags[i])
+		nn += int64(ni)
+		if err != nil {
+			return nn, err
+		}
+	}
+	ni, err := w.Write(t.texts[n])
+	nn += int64(ni)
+	return nn, err
+}
+
+// Execute substitutes template tags (placeholders) with the corresponding
+// values from the map m and writes the result to the given writer w.
+//
+// Substitution map m may contain values with the following types:
+//   * []byte - the fastest value type
+//   * string - convenient value type
+//   * TagFunc - flexible value type
+//
+// Returns the number of bytes written to w.
+func (t *Template) Execute(w io.Writer, m map[string]interface{}) (int64, error) {
+	return t.ExecuteFunc(w, func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) })
+}
+
+// ExecuteFuncString calls f on each template tag (placeholder) occurrence
+// and substitutes it with the data written to TagFunc's w.
+//
+// Returns the resulting string.
+//
+// This function is optimized for frozen templates.
+// Use ExecuteFuncString for constantly changing templates.
+func (t *Template) ExecuteFuncString(f TagFunc) string {
+	bb := t.byteBufferPool.Get()
+	if _, err := t.ExecuteFunc(bb, f); err != nil {
+		panic(fmt.Sprintf("unexpected error: %s", err))
+	}
+	s := string(bb.Bytes())
+	bb.Reset()
+	t.byteBufferPool.Put(bb)
+	return s
+}
+
+// ExecuteString substitutes template tags (placeholders) with the corresponding
+// values from the map m and returns the result.
+//
+// Substitution map m may contain values with the following types:
+//   * []byte - the fastest value type
+//   * string - convenient value type
+//   * TagFunc - flexible value type
+//
+// This function is optimized for frozen templates.
+// Use ExecuteString for constantly changing templates.
+func (t *Template) ExecuteString(m map[string]interface{}) string {
+	return t.ExecuteFuncString(func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) })
+}
+
+func stdTagFunc(w io.Writer, tag string, m map[string]interface{}) (int, error) {
+	v := m[tag]
+	if v == nil {
+		return 0, nil
+	}
+	switch value := v.(type) {
+	case []byte:
+		return w.Write(value)
+	case string:
+		return w.Write([]byte(value))
+	case TagFunc:
+		return value(w, tag)
+	default:
+		panic(fmt.Sprintf("tag=%q contains unexpected value type=%#v. Expected []byte, string or TagFunc", tag, v))
+	}
+}

vendor/github.com/valyala/fasttemplate/unsafe.go

@@ -0,0 +1,20 @@
+package fasttemplate
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+func unsafeBytes2String(b []byte) string {
+	return *(*string)(unsafe.Pointer(&b))
+}
+
+func unsafeString2Bytes(s string) []byte {
+	sh := (*reflect.StringHeader)(unsafe.Pointer(&s))
+	bh := reflect.SliceHeader{
+		Data: sh.Data,
+		Len:  sh.Len,
+		Cap:  sh.Len,
+	}
+	return *(*[]byte)(unsafe.Pointer(&bh))
+}

vendor/github.com/valyala/fasttemplate/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]
+}

vendor/github.com/valyala/fasttemplate/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

vendor/github.com/valyala/fasttemplate/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
+}