vendor: import golang.org/x/net/http2

golang.org/x/net/http2 becomes net/http/h2_bundle.go (using adonovan's
x/tools/cmd/bundle tool), becoming a hidden part of the net/http package.

golang.org/x/net/http2/hpack becomes vendor/golang.org/x/net/http2/hpack.

At git rev 7331ef52 (https://go-review.googlesource.com/15821)

Change-Id: Ia6683e6f91a481b11a778638bf65b6a338744eea
Reviewed-on: https://go-review.googlesource.com/15822Reviewed-by: Andrew Gerrand <adg@golang.org>

src/vendor/golang.org/x/net/http2/hpack/encode.go

+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hpack
+
+import (
+	"io"
+)
+
+const (
+	uint32Max              = ^uint32(0)
+	initialHeaderTableSize = 4096
+)
+
+type Encoder struct {
+	dynTab dynamicTable
+	// minSize is the minimum table size set by
+	// SetMaxDynamicTableSize after the previous Header Table Size
+	// Update.
+	minSize uint32
+	// maxSizeLimit is the maximum table size this encoder
+	// supports. This will protect the encoder from too large
+	// size.
+	maxSizeLimit uint32
+	// tableSizeUpdate indicates whether "Header Table Size
+	// Update" is required.
+	tableSizeUpdate bool
+	w               io.Writer
+	buf             []byte
+}
+
+// NewEncoder returns a new Encoder which performs HPACK encoding. An
+// encoded data is written to w.
+func NewEncoder(w io.Writer) *Encoder {
+	e := &Encoder{
+		minSize:         uint32Max,
+		maxSizeLimit:    initialHeaderTableSize,
+		tableSizeUpdate: false,
+		w:               w,
+	}
+	e.dynTab.setMaxSize(initialHeaderTableSize)
+	return e
+}
+
+// WriteField encodes f into a single Write to e's underlying Writer.
+// This function may also produce bytes for "Header Table Size Update"
+// if necessary.  If produced, it is done before encoding f.
+func (e *Encoder) WriteField(f HeaderField) error {
+	e.buf = e.buf[:0]
+
+	if e.tableSizeUpdate {
+		e.tableSizeUpdate = false
+		if e.minSize < e.dynTab.maxSize {
+			e.buf = appendTableSize(e.buf, e.minSize)
+		}
+		e.minSize = uint32Max
+		e.buf = appendTableSize(e.buf, e.dynTab.maxSize)
+	}
+
+	idx, nameValueMatch := e.searchTable(f)
+	if nameValueMatch {
+		e.buf = appendIndexed(e.buf, idx)
+	} else {
+		indexing := e.shouldIndex(f)
+		if indexing {
+			e.dynTab.add(f)
+		}
+
+		if idx == 0 {
+			e.buf = appendNewName(e.buf, f, indexing)
+		} else {
+			e.buf = appendIndexedName(e.buf, f, idx, indexing)
+		}
+	}
+	n, err := e.w.Write(e.buf)
+	if err == nil && n != len(e.buf) {
+		err = io.ErrShortWrite
+	}
+	return err
+}
+
+// searchTable searches f in both stable and dynamic header tables.
+// The static header table is searched first. Only when there is no
+// exact match for both name and value, the dynamic header table is
+// then searched. If there is no match, i is 0. If both name and value
+// match, i is the matched index and nameValueMatch becomes true. If
+// only name matches, i points to that index and nameValueMatch
+// becomes false.
+func (e *Encoder) searchTable(f HeaderField) (i uint64, nameValueMatch bool) {
+	for idx, hf := range staticTable {
+		if !constantTimeStringCompare(hf.Name, f.Name) {
+			continue
+		}
+		if i == 0 {
+			i = uint64(idx + 1)
+		}
+		if f.Sensitive {
+			continue
+		}
+		if !constantTimeStringCompare(hf.Value, f.Value) {
+			continue
+		}
+		i = uint64(idx + 1)
+		nameValueMatch = true
+		return
+	}
+
+	j, nameValueMatch := e.dynTab.search(f)
+	if nameValueMatch || (i == 0 && j != 0) {
+		i = j + uint64(len(staticTable))
+	}
+	return
+}
+
+// SetMaxDynamicTableSize changes the dynamic header table size to v.
+// The actual size is bounded by the value passed to
+// SetMaxDynamicTableSizeLimit.
+func (e *Encoder) SetMaxDynamicTableSize(v uint32) {
+	if v > e.maxSizeLimit {
+		v = e.maxSizeLimit
+	}
+	if v < e.minSize {
+		e.minSize = v
+	}
+	e.tableSizeUpdate = true
+	e.dynTab.setMaxSize(v)
+}
+
+// SetMaxDynamicTableSizeLimit changes the maximum value that can be
+// specified in SetMaxDynamicTableSize to v. By default, it is set to
+// 4096, which is the same size of the default dynamic header table
+// size described in HPACK specification. If the current maximum
+// dynamic header table size is strictly greater than v, "Header Table
+// Size Update" will be done in the next WriteField call and the
+// maximum dynamic header table size is truncated to v.
+func (e *Encoder) SetMaxDynamicTableSizeLimit(v uint32) {
+	e.maxSizeLimit = v
+	if e.dynTab.maxSize > v {
+		e.tableSizeUpdate = true
+		e.dynTab.setMaxSize(v)
+	}
+}
+
+// shouldIndex reports whether f should be indexed.
+func (e *Encoder) shouldIndex(f HeaderField) bool {
+	return !f.Sensitive && f.size() <= e.dynTab.maxSize
+}
+
+// appendIndexed appends index i, as encoded in "Indexed Header Field"
+// representation, to dst and returns the extended buffer.
+func appendIndexed(dst []byte, i uint64) []byte {
+	first := len(dst)
+	dst = appendVarInt(dst, 7, i)
+	dst[first] |= 0x80
+	return dst
+}
+
+// appendNewName appends f, as encoded in one of "Literal Header field
+// - New Name" representation variants, to dst and returns the
+// extended buffer.
+//
+// If f.Sensitive is true, "Never Indexed" representation is used. If
+// f.Sensitive is false and indexing is true, "Inremental Indexing"
+// representation is used.
+func appendNewName(dst []byte, f HeaderField, indexing bool) []byte {
+	dst = append(dst, encodeTypeByte(indexing, f.Sensitive))
+	dst = appendHpackString(dst, f.Name)
+	return appendHpackString(dst, f.Value)
+}
+
+// appendIndexedName appends f and index i referring indexed name
+// entry, as encoded in one of "Literal Header field - Indexed Name"
+// representation variants, to dst and returns the extended buffer.
+//
+// If f.Sensitive is true, "Never Indexed" representation is used. If
+// f.Sensitive is false and indexing is true, "Incremental Indexing"
+// representation is used.
+func appendIndexedName(dst []byte, f HeaderField, i uint64, indexing bool) []byte {
+	first := len(dst)
+	var n byte
+	if indexing {
+		n = 6
+	} else {
+		n = 4
+	}
+	dst = appendVarInt(dst, n, i)
+	dst[first] |= encodeTypeByte(indexing, f.Sensitive)
+	return appendHpackString(dst, f.Value)
+}
+
+// appendTableSize appends v, as encoded in "Header Table Size Update"
+// representation, to dst and returns the extended buffer.
+func appendTableSize(dst []byte, v uint32) []byte {
+	first := len(dst)
+	dst = appendVarInt(dst, 5, uint64(v))
+	dst[first] |= 0x20
+	return dst
+}
+
+// appendVarInt appends i, as encoded in variable integer form using n
+// bit prefix, to dst and returns the extended buffer.
+//
+// See
+// http://http2.github.io/http2-spec/compression.html#integer.representation
+func appendVarInt(dst []byte, n byte, i uint64) []byte {
+	k := uint64((1 << n) - 1)
+	if i < k {
+		return append(dst, byte(i))
+	}
+	dst = append(dst, byte(k))
+	i -= k
+	for ; i >= 128; i >>= 7 {
+		dst = append(dst, byte(0x80|(i&0x7f)))
+	}
+	return append(dst, byte(i))
+}
+
+// appendHpackString appends s, as encoded in "String Literal"
+// representation, to dst and returns the the extended buffer.
+//
+// s will be encoded in Huffman codes only when it produces strictly
+// shorter byte string.
+func appendHpackString(dst []byte, s string) []byte {
+	huffmanLength := HuffmanEncodeLength(s)
+	if huffmanLength < uint64(len(s)) {
+		first := len(dst)
+		dst = appendVarInt(dst, 7, huffmanLength)
+		dst = AppendHuffmanString(dst, s)
+		dst[first] |= 0x80
+	} else {
+		dst = appendVarInt(dst, 7, uint64(len(s)))
+		dst = append(dst, s...)
+	}
+	return dst
+}
+
+// encodeTypeByte returns type byte. If sensitive is true, type byte
+// for "Never Indexed" representation is returned. If sensitive is
+// false and indexing is true, type byte for "Incremental Indexing"
+// representation is returned. Otherwise, type byte for "Without
+// Indexing" is returned.
+func encodeTypeByte(indexing, sensitive bool) byte {
+	if sensitive {
+		return 0x10
+	}
+	if indexing {
+		return 0x40
+	}
+	return 0
+}

src/vendor/golang.org/x/net/http2/hpack/encode_test.go

+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hpack
+
+import (
+	"bytes"
+	"encoding/hex"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestEncoderTableSizeUpdate(t *testing.T) {
+	tests := []struct {
+		size1, size2 uint32
+		wantHex      string
+	}{
+		// Should emit 2 table size updates (2048 and 4096)
+		{2048, 4096, "3fe10f 3fe11f 82"},
+
+		// Should emit 1 table size update (2048)
+		{16384, 2048, "3fe10f 82"},
+	}
+	for _, tt := range tests {
+		var buf bytes.Buffer
+		e := NewEncoder(&buf)
+		e.SetMaxDynamicTableSize(tt.size1)
+		e.SetMaxDynamicTableSize(tt.size2)
+		if err := e.WriteField(pair(":method", "GET")); err != nil {
+			t.Fatal(err)
+		}
+		want := removeSpace(tt.wantHex)
+		if got := hex.EncodeToString(buf.Bytes()); got != want {
+			t.Errorf("e.SetDynamicTableSize %v, %v = %q; want %q", tt.size1, tt.size2, got, want)
+		}
+	}
+}
+
+func TestEncoderWriteField(t *testing.T) {
+	var buf bytes.Buffer
+	e := NewEncoder(&buf)
+	var got []HeaderField
+	d := NewDecoder(4<<10, func(f HeaderField) {
+		got = append(got, f)
+	})
+
+	tests := []struct {
+		hdrs []HeaderField
+	}{
+		{[]HeaderField{
+			pair(":method", "GET"),
+			pair(":scheme", "http"),
+			pair(":path", "/"),
+			pair(":authority", "www.example.com"),
+		}},
+		{[]HeaderField{
+			pair(":method", "GET"),
+			pair(":scheme", "http"),
+			pair(":path", "/"),
+			pair(":authority", "www.example.com"),
+			pair("cache-control", "no-cache"),
+		}},
+		{[]HeaderField{
+			pair(":method", "GET"),
+			pair(":scheme", "https"),
+			pair(":path", "/index.html"),
+			pair(":authority", "www.example.com"),
+			pair("custom-key", "custom-value"),
+		}},
+	}
+	for i, tt := range tests {
+		buf.Reset()
+		got = got[:0]
+		for _, hf := range tt.hdrs {
+			if err := e.WriteField(hf); err != nil {
+				t.Fatal(err)
+			}
+		}
+		_, err := d.Write(buf.Bytes())
+		if err != nil {
+			t.Errorf("%d. Decoder Write = %v", i, err)
+		}
+		if !reflect.DeepEqual(got, tt.hdrs) {
+			t.Errorf("%d. Decoded %+v; want %+v", i, got, tt.hdrs)
+		}
+	}
+}
+
+func TestEncoderSearchTable(t *testing.T) {
+	e := NewEncoder(nil)
+
+	e.dynTab.add(pair("foo", "bar"))
+	e.dynTab.add(pair("blake", "miz"))
+	e.dynTab.add(pair(":method", "GET"))
+
+	tests := []struct {
+		hf        HeaderField
+		wantI     uint64
+		wantMatch bool
+	}{
+		// Name and Value match
+		{pair("foo", "bar"), uint64(len(staticTable) + 3), true},
+		{pair("blake", "miz"), uint64(len(staticTable) + 2), true},
+		{pair(":method", "GET"), 2, true},
+
+		// Only name match because Sensitive == true
+		{HeaderField{":method", "GET", true}, 2, false},
+
+		// Only Name matches
+		{pair("foo", "..."), uint64(len(staticTable) + 3), false},
+		{pair("blake", "..."), uint64(len(staticTable) + 2), false},
+		{pair(":method", "..."), 2, false},
+
+		// None match
+		{pair("foo-", "bar"), 0, false},
+	}
+	for _, tt := range tests {
+		if gotI, gotMatch := e.searchTable(tt.hf); gotI != tt.wantI || gotMatch != tt.wantMatch {
+			t.Errorf("d.search(%+v) = %v, %v; want %v, %v", tt.hf, gotI, gotMatch, tt.wantI, tt.wantMatch)
+		}
+	}
+}
+
+func TestAppendVarInt(t *testing.T) {
+	tests := []struct {
+		n    byte
+		i    uint64
+		want []byte
+	}{
+		// Fits in a byte:
+		{1, 0, []byte{0}},
+		{2, 2, []byte{2}},
+		{3, 6, []byte{6}},
+		{4, 14, []byte{14}},
+		{5, 30, []byte{30}},
+		{6, 62, []byte{62}},
+		{7, 126, []byte{126}},
+		{8, 254, []byte{254}},
+
+		// Multiple bytes:
+		{5, 1337, []byte{31, 154, 10}},
+	}
+	for _, tt := range tests {
+		got := appendVarInt(nil, tt.n, tt.i)
+		if !bytes.Equal(got, tt.want) {
+			t.Errorf("appendVarInt(nil, %v, %v) = %v; want %v", tt.n, tt.i, got, tt.want)
+		}
+	}
+}
+
+func TestAppendHpackString(t *testing.T) {
+	tests := []struct {
+		s, wantHex string
+	}{
+		// Huffman encoded
+		{"www.example.com", "8c f1e3 c2e5 f23a 6ba0 ab90 f4ff"},
+
+		// Not Huffman encoded
+		{"a", "01 61"},
+
+		// zero length
+		{"", "00"},
+	}
+	for _, tt := range tests {
+		want := removeSpace(tt.wantHex)
+		buf := appendHpackString(nil, tt.s)
+		if got := hex.EncodeToString(buf); want != got {
+			t.Errorf("appendHpackString(nil, %q) = %q; want %q", tt.s, got, want)
+		}
+	}
+}
+
+func TestAppendIndexed(t *testing.T) {
+	tests := []struct {
+		i       uint64
+		wantHex string
+	}{
+		// 1 byte
+		{1, "81"},
+		{126, "fe"},
+
+		// 2 bytes
+		{127, "ff00"},
+		{128, "ff01"},
+	}
+	for _, tt := range tests {
+		want := removeSpace(tt.wantHex)
+		buf := appendIndexed(nil, tt.i)
+		if got := hex.EncodeToString(buf); want != got {
+			t.Errorf("appendIndex(nil, %v) = %q; want %q", tt.i, got, want)
+		}
+	}
+}
+
+func TestAppendNewName(t *testing.T) {
+	tests := []struct {
+		f        HeaderField
+		indexing bool
+		wantHex  string
+	}{
+		// Incremental indexing
+		{HeaderField{"custom-key", "custom-value", false}, true, "40 88 25a8 49e9 5ba9 7d7f 89 25a8 49e9 5bb8 e8b4 bf"},
+
+		// Without indexing
+		{HeaderField{"custom-key", "custom-value", false}, false, "00 88 25a8 49e9 5ba9 7d7f 89 25a8 49e9 5bb8 e8b4 bf"},
+
+		// Never indexed
+		{HeaderField{"custom-key", "custom-value", true}, true, "10 88 25a8 49e9 5ba9 7d7f 89 25a8 49e9 5bb8 e8b4 bf"},
+		{HeaderField{"custom-key", "custom-value", true}, false, "10 88 25a8 49e9 5ba9 7d7f 89 25a8 49e9 5bb8 e8b4 bf"},
+	}
+	for _, tt := range tests {
+		want := removeSpace(tt.wantHex)
+		buf := appendNewName(nil, tt.f, tt.indexing)
+		if got := hex.EncodeToString(buf); want != got {
+			t.Errorf("appendNewName(nil, %+v, %v) = %q; want %q", tt.f, tt.indexing, got, want)
+		}
+	}
+}
+
+func TestAppendIndexedName(t *testing.T) {
+	tests := []struct {
+		f        HeaderField
+		i        uint64
+		indexing bool
+		wantHex  string
+	}{
+		// Incremental indexing
+		{HeaderField{":status", "302", false}, 8, true, "48 82 6402"},
+
+		// Without indexing
+		{HeaderField{":status", "302", false}, 8, false, "08 82 6402"},
+
+		// Never indexed
+		{HeaderField{":status", "302", true}, 8, true, "18 82 6402"},
+		{HeaderField{":status", "302", true}, 8, false, "18 82 6402"},
+	}
+	for _, tt := range tests {
+		want := removeSpace(tt.wantHex)
+		buf := appendIndexedName(nil, tt.f, tt.i, tt.indexing)
+		if got := hex.EncodeToString(buf); want != got {
+			t.Errorf("appendIndexedName(nil, %+v, %v) = %q; want %q", tt.f, tt.indexing, got, want)
+		}
+	}
+}
+
+func TestAppendTableSize(t *testing.T) {
+	tests := []struct {
+		i       uint32
+		wantHex string
+	}{
+		// Fits into 1 byte
+		{30, "3e"},
+
+		// Extra byte
+		{31, "3f00"},
+		{32, "3f01"},
+	}
+	for _, tt := range tests {
+		want := removeSpace(tt.wantHex)
+		buf := appendTableSize(nil, tt.i)
+		if got := hex.EncodeToString(buf); want != got {
+			t.Errorf("appendTableSize(nil, %v) = %q; want %q", tt.i, got, want)
+		}
+	}
+}
+
+func TestEncoderSetMaxDynamicTableSize(t *testing.T) {
+	var buf bytes.Buffer
+	e := NewEncoder(&buf)
+	tests := []struct {
+		v           uint32
+		wantUpdate  bool
+		wantMinSize uint32
+		wantMaxSize uint32
+	}{
+		// Set new table size to 2048
+		{2048, true, 2048, 2048},
+
+		// Set new table size to 16384, but still limited to
+		// 4096
+		{16384, true, 2048, 4096},
+	}
+	for _, tt := range tests {
+		e.SetMaxDynamicTableSize(tt.v)
+		if got := e.tableSizeUpdate; tt.wantUpdate != got {
+			t.Errorf("e.tableSizeUpdate = %v; want %v", got, tt.wantUpdate)
+		}
+		if got := e.minSize; tt.wantMinSize != got {
+			t.Errorf("e.minSize = %v; want %v", got, tt.wantMinSize)
+		}
+		if got := e.dynTab.maxSize; tt.wantMaxSize != got {
+			t.Errorf("e.maxSize = %v; want %v", got, tt.wantMaxSize)
+		}
+	}
+}
+
+func TestEncoderSetMaxDynamicTableSizeLimit(t *testing.T) {
+	e := NewEncoder(nil)
+	// 4095 < initialHeaderTableSize means maxSize is truncated to
+	// 4095.
+	e.SetMaxDynamicTableSizeLimit(4095)
+	if got, want := e.dynTab.maxSize, uint32(4095); got != want {
+		t.Errorf("e.dynTab.maxSize = %v; want %v", got, want)
+	}
+	if got, want := e.maxSizeLimit, uint32(4095); got != want {
+		t.Errorf("e.maxSizeLimit = %v; want %v", got, want)
+	}
+	if got, want := e.tableSizeUpdate, true; got != want {
+		t.Errorf("e.tableSizeUpdate = %v; want %v", got, want)
+	}
+	// maxSize will be truncated to maxSizeLimit
+	e.SetMaxDynamicTableSize(16384)
+	if got, want := e.dynTab.maxSize, uint32(4095); got != want {
+		t.Errorf("e.dynTab.maxSize = %v; want %v", got, want)
+	}
+	// 8192 > current maxSizeLimit, so maxSize does not change.
+	e.SetMaxDynamicTableSizeLimit(8192)
+	if got, want := e.dynTab.maxSize, uint32(4095); got != want {
+		t.Errorf("e.dynTab.maxSize = %v; want %v", got, want)
+	}
+	if got, want := e.maxSizeLimit, uint32(8192); got != want {
+		t.Errorf("e.maxSizeLimit = %v; want %v", got, want)
+	}
+}
+
+func removeSpace(s string) string {
+	return strings.Replace(s, " ", "", -1)
+}

src/vendor/golang.org/x/net/http2/hpack/huffman.go

+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hpack
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"sync"
+)
+
+var bufPool = sync.Pool{
+	New: func() interface{} { return new(bytes.Buffer) },
+}
+
+// HuffmanDecode decodes the string in v and writes the expanded
+// result to w, returning the number of bytes written to w and the
+// Write call's return value. At most one Write call is made.
+func HuffmanDecode(w io.Writer, v []byte) (int, error) {
+	buf := bufPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	defer bufPool.Put(buf)
+	if err := huffmanDecode(buf, 0, v); err != nil {
+		return 0, err
+	}
+	return w.Write(buf.Bytes())
+}
+
+// HuffmanDecodeToString decodes the string in v.
+func HuffmanDecodeToString(v []byte) (string, error) {
+	buf := bufPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	defer bufPool.Put(buf)
+	if err := huffmanDecode(buf, 0, v); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
+// ErrInvalidHuffman is returned for errors found decoding
+// Huffman-encoded strings.
+var ErrInvalidHuffman = errors.New("hpack: invalid Huffman-encoded data")
+
+// huffmanDecode decodes v to buf.
+// If maxLen is greater than 0, attempts to write more to buf than
+// maxLen bytes will return ErrStringLength.
+func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
+	n := rootHuffmanNode
+	cur, nbits := uint(0), uint8(0)
+	for _, b := range v {
+		cur = cur<<8 | uint(b)
+		nbits += 8
+		for nbits >= 8 {
+			idx := byte(cur >> (nbits - 8))
+			n = n.children[idx]
+			if n == nil {
+				return ErrInvalidHuffman
+			}
+			if n.children == nil {
+				if maxLen != 0 && buf.Len() == maxLen {
+					return ErrStringLength
+				}
+				buf.WriteByte(n.sym)
+				nbits -= n.codeLen
+				n = rootHuffmanNode
+			} else {
+				nbits -= 8
+			}
+		}
+	}
+	for nbits > 0 {
+		n = n.children[byte(cur<<(8-nbits))]
+		if n.children != nil || n.codeLen > nbits {
+			break
+		}
+		buf.WriteByte(n.sym)
+		nbits -= n.codeLen
+		n = rootHuffmanNode
+	}
+	return nil
+}
+
+type node struct {
+	// children is non-nil for internal nodes
+	children []*node
+
+	// The following are only valid if children is nil:
+	codeLen uint8 // number of bits that led to the output of sym
+	sym     byte  // output symbol
+}
+
+func newInternalNode() *node {
+	return &node{children: make([]*node, 256)}
+}
+
+var rootHuffmanNode = newInternalNode()
+
+func init() {
+	if len(huffmanCodes) != 256 {
+		panic("unexpected size")
+	}
+	for i, code := range huffmanCodes {
+		addDecoderNode(byte(i), code, huffmanCodeLen[i])
+	}
+}
+
+func addDecoderNode(sym byte, code uint32, codeLen uint8) {
+	cur := rootHuffmanNode
+	for codeLen > 8 {
+		codeLen -= 8
+		i := uint8(code >> codeLen)
+		if cur.children[i] == nil {
+			cur.children[i] = newInternalNode()
+		}
+		cur = cur.children[i]
+	}
+	shift := 8 - codeLen
+	start, end := int(uint8(code<<shift)), int(1<<shift)
+	for i := start; i < start+end; i++ {
+		cur.children[i] = &node{sym: sym, codeLen: codeLen}
+	}
+}
+
+// AppendHuffmanString appends s, as encoded in Huffman codes, to dst
+// and returns the extended buffer.
+func AppendHuffmanString(dst []byte, s string) []byte {
+	rembits := uint8(8)
+
+	for i := 0; i < len(s); i++ {
+		if rembits == 8 {
+			dst = append(dst, 0)
+		}
+		dst, rembits = appendByteToHuffmanCode(dst, rembits, s[i])
+	}
+
+	if rembits < 8 {
+		// special EOS symbol
+		code := uint32(0x3fffffff)
+		nbits := uint8(30)
+
+		t := uint8(code >> (nbits - rembits))
+		dst[len(dst)-1] |= t
+	}
+
+	return dst
+}
+
+// HuffmanEncodeLength returns the number of bytes required to encode
+// s in Huffman codes. The result is round up to byte boundary.
+func HuffmanEncodeLength(s string) uint64 {
+	n := uint64(0)
+	for i := 0; i < len(s); i++ {
+		n += uint64(huffmanCodeLen[s[i]])
+	}
+	return (n + 7) / 8
+}
+
+// appendByteToHuffmanCode appends Huffman code for c to dst and
+// returns the extended buffer and the remaining bits in the last
+// element. The appending is not byte aligned and the remaining bits
+// in the last element of dst is given in rembits.
+func appendByteToHuffmanCode(dst []byte, rembits uint8, c byte) ([]byte, uint8) {
+	code := huffmanCodes[c]
+	nbits := huffmanCodeLen[c]
+
+	for {
+		if rembits > nbits {
+			t := uint8(code << (rembits - nbits))
+			dst[len(dst)-1] |= t
+			rembits -= nbits
+			break
+		}
+
+		t := uint8(code >> (nbits - rembits))
+		dst[len(dst)-1] |= t
+
+		nbits -= rembits
+		rembits = 8
+
+		if nbits == 0 {
+			break
+		}
+
+		dst = append(dst, 0)
+	}
+
+	return dst, rembits
+}

src/vendor/golang.org/x/net/http2/hpack/tables.go

+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hpack
+
+func pair(name, value string) HeaderField {
+	return HeaderField{Name: name, Value: value}
+}
+
+// http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07#appendix-B
+var staticTable = [...]HeaderField{
+	pair(":authority", ""), // index 1 (1-based)
+	pair(":method", "GET"),
+	pair(":method", "POST"),
+	pair(":path", "/"),
+	pair(":path", "/index.html"),
+	pair(":scheme", "http"),
+	pair(":scheme", "https"),
+	pair(":status", "200"),
+	pair(":status", "204"),
+	pair(":status", "206"),
+	pair(":status", "304"),
+	pair(":status", "400"),
+	pair(":status", "404"),
+	pair(":status", "500"),
+	pair("accept-charset", ""),
+	pair("accept-encoding", "gzip, deflate"),
+	pair("accept-language", ""),
+	pair("accept-ranges", ""),
+	pair("accept", ""),
+	pair("access-control-allow-origin", ""),
+	pair("age", ""),
+	pair("allow", ""),
+	pair("authorization", ""),
+	pair("cache-control", ""),
+	pair("content-disposition", ""),
+	pair("content-encoding", ""),
+	pair("content-language", ""),
+	pair("content-length", ""),
+	pair("content-location", ""),
+	pair("content-range", ""),
+	pair("content-type", ""),
+	pair("cookie", ""),
+	pair("date", ""),
+	pair("etag", ""),
+	pair("expect", ""),
+	pair("expires", ""),
+	pair("from", ""),
+	pair("host", ""),
+	pair("if-match", ""),
+	pair("if-modified-since", ""),
+	pair("if-none-match", ""),
+	pair("if-range", ""),
+	pair("if-unmodified-since", ""),
+	pair("last-modified", ""),
+	pair("link", ""),
+	pair("location", ""),
+	pair("max-forwards", ""),
+	pair("proxy-authenticate", ""),
+	pair("proxy-authorization", ""),
+	pair("range", ""),
+	pair("referer", ""),
+	pair("refresh", ""),
+	pair("retry-after", ""),
+	pair("server", ""),
+	pair("set-cookie", ""),
+	pair("strict-transport-security", ""),
+	pair("transfer-encoding", ""),
+	pair("user-agent", ""),
+	pair("vary", ""),
+	pair("via", ""),
+	pair("www-authenticate", ""),
+}
+
+var huffmanCodes = [256]uint32{
+	0x1ff8,
+	0x7fffd8,
+	0xfffffe2,
+	0xfffffe3,
+	0xfffffe4,
+	0xfffffe5,
+	0xfffffe6,
+	0xfffffe7,
+	0xfffffe8,
+	0xffffea,
+	0x3ffffffc,
+	0xfffffe9,
+	0xfffffea,
+	0x3ffffffd,
+	0xfffffeb,
+	0xfffffec,
+	0xfffffed,
+	0xfffffee,
+	0xfffffef,
+	0xffffff0,
+	0xffffff1,
+	0xffffff2,
+	0x3ffffffe,
+	0xffffff3,
+	0xffffff4,
+	0xffffff5,
+	0xffffff6,
+	0xffffff7,
+	0xffffff8,
+	0xffffff9,
+	0xffffffa,
+	0xffffffb,
+	0x14,
+	0x3f8,
+	0x3f9,
+	0xffa,
+	0x1ff9,
+	0x15,
+	0xf8,
+	0x7fa,
+	0x3fa,
+	0x3fb,
+	0xf9,
+	0x7fb,
+	0xfa,
+	0x16,
+	0x17,
+	0x18,
+	0x0,
+	0x1,
+	0x2,
+	0x19,
+	0x1a,
+	0x1b,
+	0x1c,
+	0x1d,
+	0x1e,
+	0x1f,
+	0x5c,
+	0xfb,
+	0x7ffc,
+	0x20,
+	0xffb,
+	0x3fc,
+	0x1ffa,
+	0x21,
+	0x5d,
+	0x5e,
+	0x5f,
+	0x60,
+	0x61,
+	0x62,
+	0x63,
+	0x64,
+	0x65,
+	0x66,
+	0x67,
+	0x68,
+	0x69,
+	0x6a,
+	0x6b,
+	0x6c,
+	0x6d,
+	0x6e,
+	0x6f,
+	0x70,
+	0x71,
+	0x72,
+	0xfc,
+	0x73,
+	0xfd,
+	0x1ffb,
+	0x7fff0,
+	0x1ffc,
+	0x3ffc,
+	0x22,
+	0x7ffd,
+	0x3,
+	0x23,
+	0x4,
+	0x24,
+	0x5,
+	0x25,
+	0x26,
+	0x27,
+	0x6,
+	0x74,
+	0x75,
+	0x28,
+	0x29,
+	0x2a,
+	0x7,
+	0x2b,
+	0x76,
+	0x2c,
+	0x8,
+	0x9,
+	0x2d,
+	0x77,
+	0x78,
+	0x79,
+	0x7a,
+	0x7b,
+	0x7ffe,
+	0x7fc,
+	0x3ffd,
+	0x1ffd,
+	0xffffffc,
+	0xfffe6,
+	0x3fffd2,
+	0xfffe7,
+	0xfffe8,
+	0x3fffd3,
+	0x3fffd4,
+	0x3fffd5,
+	0x7fffd9,
+	0x3fffd6,
+	0x7fffda,
+	0x7fffdb,
+	0x7fffdc,
+	0x7fffdd,
+	0x7fffde,
+	0xffffeb,
+	0x7fffdf,
+	0xffffec,
+	0xffffed,
+	0x3fffd7,
+	0x7fffe0,
+	0xffffee,
+	0x7fffe1,
+	0x7fffe2,
+	0x7fffe3,
+	0x7fffe4,
+	0x1fffdc,
+	0x3fffd8,
+	0x7fffe5,
+	0x3fffd9,
+	0x7fffe6,
+	0x7fffe7,
+	0xffffef,
+	0x3fffda,
+	0x1fffdd,
+	0xfffe9,
+	0x3fffdb,
+	0x3fffdc,
+	0x7fffe8,
+	0x7fffe9,
+	0x1fffde,
+	0x7fffea,
+	0x3fffdd,
+	0x3fffde,
+	0xfffff0,
+	0x1fffdf,
+	0x3fffdf,
+	0x7fffeb,
+	0x7fffec,
+	0x1fffe0,
+	0x1fffe1,
+	0x3fffe0,
+	0x1fffe2,
+	0x7fffed,
+	0x3fffe1,
+	0x7fffee,
+	0x7fffef,
+	0xfffea,
+	0x3fffe2,
+	0x3fffe3,
+	0x3fffe4,
+	0x7ffff0,
+	0x3fffe5,
+	0x3fffe6,
+	0x7ffff1,
+	0x3ffffe0,
+	0x3ffffe1,
+	0xfffeb,
+	0x7fff1,
+	0x3fffe7,
+	0x7ffff2,
+	0x3fffe8,
+	0x1ffffec,
+	0x3ffffe2,
+	0x3ffffe3,
+	0x3ffffe4,
+	0x7ffffde,
+	0x7ffffdf,
+	0x3ffffe5,
+	0xfffff1,
+	0x1ffffed,
+	0x7fff2,
+	0x1fffe3,
+	0x3ffffe6,
+	0x7ffffe0,
+	0x7ffffe1,
+	0x3ffffe7,
+	0x7ffffe2,
+	0xfffff2,
+	0x1fffe4,
+	0x1fffe5,
+	0x3ffffe8,
+	0x3ffffe9,
+	0xffffffd,
+	0x7ffffe3,
+	0x7ffffe4,
+	0x7ffffe5,
+	0xfffec,
+	0xfffff3,
+	0xfffed,
+	0x1fffe6,
+	0x3fffe9,
+	0x1fffe7,
+	0x1fffe8,
+	0x7ffff3,
+	0x3fffea,
+	0x3fffeb,
+	0x1ffffee,
+	0x1ffffef,
+	0xfffff4,
+	0xfffff5,
+	0x3ffffea,
+	0x7ffff4,
+	0x3ffffeb,
+	0x7ffffe6,
+	0x3ffffec,
+	0x3ffffed,
+	0x7ffffe7,
+	0x7ffffe8,
+	0x7ffffe9,
+	0x7ffffea,
+	0x7ffffeb,
+	0xffffffe,
+	0x7ffffec,
+	0x7ffffed,
+	0x7ffffee,
+	0x7ffffef,
+	0x7fffff0,
+	0x3ffffee,
+}
+
+var huffmanCodeLen = [256]uint8{
+	13, 23, 28, 28, 28, 28, 28, 28, 28, 24, 30, 28, 28, 30, 28, 28,
+	28, 28, 28, 28, 28, 28, 30, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+	6, 10, 10, 12, 13, 6, 8, 11, 10, 10, 8, 11, 8, 6, 6, 6,
+	5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 8, 15, 6, 12, 10,
+	13, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+	7, 7, 7, 7, 7, 7, 7, 7, 8, 7, 8, 13, 19, 13, 14, 6,
+	15, 5, 6, 5, 6, 5, 6, 6, 6, 5, 7, 7, 6, 6, 6, 5,
+	6, 7, 6, 5, 5, 6, 7, 7, 7, 7, 7, 15, 11, 14, 13, 28,
+	20, 22, 20, 20, 22, 22, 22, 23, 22, 23, 23, 23, 23, 23, 24, 23,
+	24, 24, 22, 23, 24, 23, 23, 23, 23, 21, 22, 23, 22, 23, 23, 24,
+	22, 21, 20, 22, 22, 23, 23, 21, 23, 22, 22, 24, 21, 22, 23, 23,
+	21, 21, 22, 21, 23, 22, 23, 23, 20, 22, 22, 22, 23, 22, 22, 23,
+	26, 26, 20, 19, 22, 23, 22, 25, 26, 26, 26, 27, 27, 26, 24, 25,
+	19, 21, 26, 27, 27, 26, 27, 24, 21, 21, 26, 26, 28, 27, 27, 27,
+	20, 24, 20, 21, 22, 21, 21, 23, 22, 22, 25, 25, 24, 24, 26, 23,
+	26, 27, 26, 26, 27, 27, 27, 27, 27, 28, 27, 27, 27, 27, 27, 26,
+}