initial add - go fmt on grpc
Change-Id: Ib0afadd2fe5571d1456a091f94f5644458f7d3f4
diff --git a/vendor/golang.org/x/net/http2/hpack/hpack.go b/vendor/golang.org/x/net/http2/hpack/hpack.go
new file mode 100644
index 0000000..85f18a2
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/hpack/hpack.go
@@ -0,0 +1,504 @@
+// 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 implements HPACK, a compression format for
+// efficiently representing HTTP header fields in the context of HTTP/2.
+//
+// See http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-09
+package hpack
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+)
+
+// A DecodingError is something the spec defines as a decoding error.
+type DecodingError struct {
+ Err error
+}
+
+func (de DecodingError) Error() string {
+ return fmt.Sprintf("decoding error: %v", de.Err)
+}
+
+// An InvalidIndexError is returned when an encoder references a table
+// entry before the static table or after the end of the dynamic table.
+type InvalidIndexError int
+
+func (e InvalidIndexError) Error() string {
+ return fmt.Sprintf("invalid indexed representation index %d", int(e))
+}
+
+// A HeaderField is a name-value pair. Both the name and value are
+// treated as opaque sequences of octets.
+type HeaderField struct {
+ Name, Value string
+
+ // Sensitive means that this header field should never be
+ // indexed.
+ Sensitive bool
+}
+
+// IsPseudo reports whether the header field is an http2 pseudo header.
+// That is, it reports whether it starts with a colon.
+// It is not otherwise guaranteed to be a valid pseudo header field,
+// though.
+func (hf HeaderField) IsPseudo() bool {
+ return len(hf.Name) != 0 && hf.Name[0] == ':'
+}
+
+func (hf HeaderField) String() string {
+ var suffix string
+ if hf.Sensitive {
+ suffix = " (sensitive)"
+ }
+ return fmt.Sprintf("header field %q = %q%s", hf.Name, hf.Value, suffix)
+}
+
+// Size returns the size of an entry per RFC 7541 section 4.1.
+func (hf HeaderField) Size() uint32 {
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.4.1
+ // "The size of the dynamic table is the sum of the size of
+ // its entries. The size of an entry is the sum of its name's
+ // length in octets (as defined in Section 5.2), its value's
+ // length in octets (see Section 5.2), plus 32. The size of
+ // an entry is calculated using the length of the name and
+ // value without any Huffman encoding applied."
+
+ // This can overflow if somebody makes a large HeaderField
+ // Name and/or Value by hand, but we don't care, because that
+ // won't happen on the wire because the encoding doesn't allow
+ // it.
+ return uint32(len(hf.Name) + len(hf.Value) + 32)
+}
+
+// A Decoder is the decoding context for incremental processing of
+// header blocks.
+type Decoder struct {
+ dynTab dynamicTable
+ emit func(f HeaderField)
+
+ emitEnabled bool // whether calls to emit are enabled
+ maxStrLen int // 0 means unlimited
+
+ // buf is the unparsed buffer. It's only written to
+ // saveBuf if it was truncated in the middle of a header
+ // block. Because it's usually not owned, we can only
+ // process it under Write.
+ buf []byte // not owned; only valid during Write
+
+ // saveBuf is previous data passed to Write which we weren't able
+ // to fully parse before. Unlike buf, we own this data.
+ saveBuf bytes.Buffer
+
+ firstField bool // processing the first field of the header block
+}
+
+// NewDecoder returns a new decoder with the provided maximum dynamic
+// table size. The emitFunc will be called for each valid field
+// parsed, in the same goroutine as calls to Write, before Write returns.
+func NewDecoder(maxDynamicTableSize uint32, emitFunc func(f HeaderField)) *Decoder {
+ d := &Decoder{
+ emit: emitFunc,
+ emitEnabled: true,
+ firstField: true,
+ }
+ d.dynTab.table.init()
+ d.dynTab.allowedMaxSize = maxDynamicTableSize
+ d.dynTab.setMaxSize(maxDynamicTableSize)
+ return d
+}
+
+// ErrStringLength is returned by Decoder.Write when the max string length
+// (as configured by Decoder.SetMaxStringLength) would be violated.
+var ErrStringLength = errors.New("hpack: string too long")
+
+// SetMaxStringLength sets the maximum size of a HeaderField name or
+// value string. If a string exceeds this length (even after any
+// decompression), Write will return ErrStringLength.
+// A value of 0 means unlimited and is the default from NewDecoder.
+func (d *Decoder) SetMaxStringLength(n int) {
+ d.maxStrLen = n
+}
+
+// SetEmitFunc changes the callback used when new header fields
+// are decoded.
+// It must be non-nil. It does not affect EmitEnabled.
+func (d *Decoder) SetEmitFunc(emitFunc func(f HeaderField)) {
+ d.emit = emitFunc
+}
+
+// SetEmitEnabled controls whether the emitFunc provided to NewDecoder
+// should be called. The default is true.
+//
+// This facility exists to let servers enforce MAX_HEADER_LIST_SIZE
+// while still decoding and keeping in-sync with decoder state, but
+// without doing unnecessary decompression or generating unnecessary
+// garbage for header fields past the limit.
+func (d *Decoder) SetEmitEnabled(v bool) { d.emitEnabled = v }
+
+// EmitEnabled reports whether calls to the emitFunc provided to NewDecoder
+// are currently enabled. The default is true.
+func (d *Decoder) EmitEnabled() bool { return d.emitEnabled }
+
+// TODO: add method *Decoder.Reset(maxSize, emitFunc) to let callers re-use Decoders and their
+// underlying buffers for garbage reasons.
+
+func (d *Decoder) SetMaxDynamicTableSize(v uint32) {
+ d.dynTab.setMaxSize(v)
+}
+
+// SetAllowedMaxDynamicTableSize sets the upper bound that the encoded
+// stream (via dynamic table size updates) may set the maximum size
+// to.
+func (d *Decoder) SetAllowedMaxDynamicTableSize(v uint32) {
+ d.dynTab.allowedMaxSize = v
+}
+
+type dynamicTable struct {
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.2.3.2
+ table headerFieldTable
+ size uint32 // in bytes
+ maxSize uint32 // current maxSize
+ allowedMaxSize uint32 // maxSize may go up to this, inclusive
+}
+
+func (dt *dynamicTable) setMaxSize(v uint32) {
+ dt.maxSize = v
+ dt.evict()
+}
+
+func (dt *dynamicTable) add(f HeaderField) {
+ dt.table.addEntry(f)
+ dt.size += f.Size()
+ dt.evict()
+}
+
+// If we're too big, evict old stuff.
+func (dt *dynamicTable) evict() {
+ var n int
+ for dt.size > dt.maxSize && n < dt.table.len() {
+ dt.size -= dt.table.ents[n].Size()
+ n++
+ }
+ dt.table.evictOldest(n)
+}
+
+func (d *Decoder) maxTableIndex() int {
+ // This should never overflow. RFC 7540 Section 6.5.2 limits the size of
+ // the dynamic table to 2^32 bytes, where each entry will occupy more than
+ // one byte. Further, the staticTable has a fixed, small length.
+ return d.dynTab.table.len() + staticTable.len()
+}
+
+func (d *Decoder) at(i uint64) (hf HeaderField, ok bool) {
+ // See Section 2.3.3.
+ if i == 0 {
+ return
+ }
+ if i <= uint64(staticTable.len()) {
+ return staticTable.ents[i-1], true
+ }
+ if i > uint64(d.maxTableIndex()) {
+ return
+ }
+ // In the dynamic table, newer entries have lower indices.
+ // However, dt.ents[0] is the oldest entry. Hence, dt.ents is
+ // the reversed dynamic table.
+ dt := d.dynTab.table
+ return dt.ents[dt.len()-(int(i)-staticTable.len())], true
+}
+
+// Decode decodes an entire block.
+//
+// TODO: remove this method and make it incremental later? This is
+// easier for debugging now.
+func (d *Decoder) DecodeFull(p []byte) ([]HeaderField, error) {
+ var hf []HeaderField
+ saveFunc := d.emit
+ defer func() { d.emit = saveFunc }()
+ d.emit = func(f HeaderField) { hf = append(hf, f) }
+ if _, err := d.Write(p); err != nil {
+ return nil, err
+ }
+ if err := d.Close(); err != nil {
+ return nil, err
+ }
+ return hf, nil
+}
+
+// Close declares that the decoding is complete and resets the Decoder
+// to be reused again for a new header block. If there is any remaining
+// data in the decoder's buffer, Close returns an error.
+func (d *Decoder) Close() error {
+ if d.saveBuf.Len() > 0 {
+ d.saveBuf.Reset()
+ return DecodingError{errors.New("truncated headers")}
+ }
+ d.firstField = true
+ return nil
+}
+
+func (d *Decoder) Write(p []byte) (n int, err error) {
+ if len(p) == 0 {
+ // Prevent state machine CPU attacks (making us redo
+ // work up to the point of finding out we don't have
+ // enough data)
+ return
+ }
+ // Only copy the data if we have to. Optimistically assume
+ // that p will contain a complete header block.
+ if d.saveBuf.Len() == 0 {
+ d.buf = p
+ } else {
+ d.saveBuf.Write(p)
+ d.buf = d.saveBuf.Bytes()
+ d.saveBuf.Reset()
+ }
+
+ for len(d.buf) > 0 {
+ err = d.parseHeaderFieldRepr()
+ if err == errNeedMore {
+ // Extra paranoia, making sure saveBuf won't
+ // get too large. All the varint and string
+ // reading code earlier should already catch
+ // overlong things and return ErrStringLength,
+ // but keep this as a last resort.
+ const varIntOverhead = 8 // conservative
+ if d.maxStrLen != 0 && int64(len(d.buf)) > 2*(int64(d.maxStrLen)+varIntOverhead) {
+ return 0, ErrStringLength
+ }
+ d.saveBuf.Write(d.buf)
+ return len(p), nil
+ }
+ d.firstField = false
+ if err != nil {
+ break
+ }
+ }
+ return len(p), err
+}
+
+// errNeedMore is an internal sentinel error value that means the
+// buffer is truncated and we need to read more data before we can
+// continue parsing.
+var errNeedMore = errors.New("need more data")
+
+type indexType int
+
+const (
+ indexedTrue indexType = iota
+ indexedFalse
+ indexedNever
+)
+
+func (v indexType) indexed() bool { return v == indexedTrue }
+func (v indexType) sensitive() bool { return v == indexedNever }
+
+// returns errNeedMore if there isn't enough data available.
+// any other error is fatal.
+// consumes d.buf iff it returns nil.
+// precondition: must be called with len(d.buf) > 0
+func (d *Decoder) parseHeaderFieldRepr() error {
+ b := d.buf[0]
+ switch {
+ case b&128 != 0:
+ // Indexed representation.
+ // High bit set?
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.6.1
+ return d.parseFieldIndexed()
+ case b&192 == 64:
+ // 6.2.1 Literal Header Field with Incremental Indexing
+ // 0b10xxxxxx: top two bits are 10
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.1
+ return d.parseFieldLiteral(6, indexedTrue)
+ case b&240 == 0:
+ // 6.2.2 Literal Header Field without Indexing
+ // 0b0000xxxx: top four bits are 0000
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.2
+ return d.parseFieldLiteral(4, indexedFalse)
+ case b&240 == 16:
+ // 6.2.3 Literal Header Field never Indexed
+ // 0b0001xxxx: top four bits are 0001
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.6.2.3
+ return d.parseFieldLiteral(4, indexedNever)
+ case b&224 == 32:
+ // 6.3 Dynamic Table Size Update
+ // Top three bits are '001'.
+ // http://http2.github.io/http2-spec/compression.html#rfc.section.6.3
+ return d.parseDynamicTableSizeUpdate()
+ }
+
+ return DecodingError{errors.New("invalid encoding")}
+}
+
+// (same invariants and behavior as parseHeaderFieldRepr)
+func (d *Decoder) parseFieldIndexed() error {
+ buf := d.buf
+ idx, buf, err := readVarInt(7, buf)
+ if err != nil {
+ return err
+ }
+ hf, ok := d.at(idx)
+ if !ok {
+ return DecodingError{InvalidIndexError(idx)}
+ }
+ d.buf = buf
+ return d.callEmit(HeaderField{Name: hf.Name, Value: hf.Value})
+}
+
+// (same invariants and behavior as parseHeaderFieldRepr)
+func (d *Decoder) parseFieldLiteral(n uint8, it indexType) error {
+ buf := d.buf
+ nameIdx, buf, err := readVarInt(n, buf)
+ if err != nil {
+ return err
+ }
+
+ var hf HeaderField
+ wantStr := d.emitEnabled || it.indexed()
+ if nameIdx > 0 {
+ ihf, ok := d.at(nameIdx)
+ if !ok {
+ return DecodingError{InvalidIndexError(nameIdx)}
+ }
+ hf.Name = ihf.Name
+ } else {
+ hf.Name, buf, err = d.readString(buf, wantStr)
+ if err != nil {
+ return err
+ }
+ }
+ hf.Value, buf, err = d.readString(buf, wantStr)
+ if err != nil {
+ return err
+ }
+ d.buf = buf
+ if it.indexed() {
+ d.dynTab.add(hf)
+ }
+ hf.Sensitive = it.sensitive()
+ return d.callEmit(hf)
+}
+
+func (d *Decoder) callEmit(hf HeaderField) error {
+ if d.maxStrLen != 0 {
+ if len(hf.Name) > d.maxStrLen || len(hf.Value) > d.maxStrLen {
+ return ErrStringLength
+ }
+ }
+ if d.emitEnabled {
+ d.emit(hf)
+ }
+ return nil
+}
+
+// (same invariants and behavior as parseHeaderFieldRepr)
+func (d *Decoder) parseDynamicTableSizeUpdate() error {
+ // RFC 7541, sec 4.2: This dynamic table size update MUST occur at the
+ // beginning of the first header block following the change to the dynamic table size.
+ if !d.firstField && d.dynTab.size > 0 {
+ return DecodingError{errors.New("dynamic table size update MUST occur at the beginning of a header block")}
+ }
+
+ buf := d.buf
+ size, buf, err := readVarInt(5, buf)
+ if err != nil {
+ return err
+ }
+ if size > uint64(d.dynTab.allowedMaxSize) {
+ return DecodingError{errors.New("dynamic table size update too large")}
+ }
+ d.dynTab.setMaxSize(uint32(size))
+ d.buf = buf
+ return nil
+}
+
+var errVarintOverflow = DecodingError{errors.New("varint integer overflow")}
+
+// readVarInt reads an unsigned variable length integer off the
+// beginning of p. n is the parameter as described in
+// http://http2.github.io/http2-spec/compression.html#rfc.section.5.1.
+//
+// n must always be between 1 and 8.
+//
+// The returned remain buffer is either a smaller suffix of p, or err != nil.
+// The error is errNeedMore if p doesn't contain a complete integer.
+func readVarInt(n byte, p []byte) (i uint64, remain []byte, err error) {
+ if n < 1 || n > 8 {
+ panic("bad n")
+ }
+ if len(p) == 0 {
+ return 0, p, errNeedMore
+ }
+ i = uint64(p[0])
+ if n < 8 {
+ i &= (1 << uint64(n)) - 1
+ }
+ if i < (1<<uint64(n))-1 {
+ return i, p[1:], nil
+ }
+
+ origP := p
+ p = p[1:]
+ var m uint64
+ for len(p) > 0 {
+ b := p[0]
+ p = p[1:]
+ i += uint64(b&127) << m
+ if b&128 == 0 {
+ return i, p, nil
+ }
+ m += 7
+ if m >= 63 { // TODO: proper overflow check. making this up.
+ return 0, origP, errVarintOverflow
+ }
+ }
+ return 0, origP, errNeedMore
+}
+
+// readString decodes an hpack string from p.
+//
+// wantStr is whether s will be used. If false, decompression and
+// []byte->string garbage are skipped if s will be ignored
+// anyway. This does mean that huffman decoding errors for non-indexed
+// strings past the MAX_HEADER_LIST_SIZE are ignored, but the server
+// is returning an error anyway, and because they're not indexed, the error
+// won't affect the decoding state.
+func (d *Decoder) readString(p []byte, wantStr bool) (s string, remain []byte, err error) {
+ if len(p) == 0 {
+ return "", p, errNeedMore
+ }
+ isHuff := p[0]&128 != 0
+ strLen, p, err := readVarInt(7, p)
+ if err != nil {
+ return "", p, err
+ }
+ if d.maxStrLen != 0 && strLen > uint64(d.maxStrLen) {
+ return "", nil, ErrStringLength
+ }
+ if uint64(len(p)) < strLen {
+ return "", p, errNeedMore
+ }
+ if !isHuff {
+ if wantStr {
+ s = string(p[:strLen])
+ }
+ return s, p[strLen:], nil
+ }
+
+ if wantStr {
+ buf := bufPool.Get().(*bytes.Buffer)
+ buf.Reset() // don't trust others
+ defer bufPool.Put(buf)
+ if err := huffmanDecode(buf, d.maxStrLen, p[:strLen]); err != nil {
+ buf.Reset()
+ return "", nil, err
+ }
+ s = buf.String()
+ buf.Reset() // be nice to GC
+ }
+ return s, p[strLen:], nil
+}