diff options
Diffstat (limited to 'vendor/github.com/gogo/protobuf/proto/decode.go')
| -rw-r--r-- | vendor/github.com/gogo/protobuf/proto/decode.go | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/vendor/github.com/gogo/protobuf/proto/decode.go b/vendor/github.com/gogo/protobuf/proto/decode.go new file mode 100644 index 0000000..d9aa3c4 --- /dev/null +++ b/vendor/github.com/gogo/protobuf/proto/decode.go @@ -0,0 +1,428 @@ +// Go support for Protocol Buffers - Google's data interchange format +// +// Copyright 2010 The Go Authors. All rights reserved. +// https://github.com/golang/protobuf +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +package proto + +/* + * Routines for decoding protocol buffer data to construct in-memory representations. + */ + +import ( + "errors" + "fmt" + "io" +) + +// errOverflow is returned when an integer is too large to be represented. +var errOverflow = errors.New("proto: integer overflow") + +// ErrInternalBadWireType is returned by generated code when an incorrect +// wire type is encountered. It does not get returned to user code. +var ErrInternalBadWireType = errors.New("proto: internal error: bad wiretype for oneof") + +// DecodeVarint reads a varint-encoded integer from the slice. +// It returns the integer and the number of bytes consumed, or +// zero if there is not enough. +// This is the format for the +// int32, int64, uint32, uint64, bool, and enum +// protocol buffer types. +func DecodeVarint(buf []byte) (x uint64, n int) { + for shift := uint(0); shift < 64; shift += 7 { + if n >= len(buf) { + return 0, 0 + } + b := uint64(buf[n]) + n++ + x |= (b & 0x7F) << shift + if (b & 0x80) == 0 { + return x, n + } + } + + // The number is too large to represent in a 64-bit value. + return 0, 0 +} + +func (p *Buffer) decodeVarintSlow() (x uint64, err error) { + i := p.index + l := len(p.buf) + + for shift := uint(0); shift < 64; shift += 7 { + if i >= l { + err = io.ErrUnexpectedEOF + return + } + b := p.buf[i] + i++ + x |= (uint64(b) & 0x7F) << shift + if b < 0x80 { + p.index = i + return + } + } + + // The number is too large to represent in a 64-bit value. + err = errOverflow + return +} + +// DecodeVarint reads a varint-encoded integer from the Buffer. +// This is the format for the +// int32, int64, uint32, uint64, bool, and enum +// protocol buffer types. +func (p *Buffer) DecodeVarint() (x uint64, err error) { + i := p.index + buf := p.buf + + if i >= len(buf) { + return 0, io.ErrUnexpectedEOF + } else if buf[i] < 0x80 { + p.index++ + return uint64(buf[i]), nil + } else if len(buf)-i < 10 { + return p.decodeVarintSlow() + } + + var b uint64 + // we already checked the first byte + x = uint64(buf[i]) - 0x80 + i++ + + b = uint64(buf[i]) + i++ + x += b << 7 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 7 + + b = uint64(buf[i]) + i++ + x += b << 14 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 14 + + b = uint64(buf[i]) + i++ + x += b << 21 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 21 + + b = uint64(buf[i]) + i++ + x += b << 28 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 28 + + b = uint64(buf[i]) + i++ + x += b << 35 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 35 + + b = uint64(buf[i]) + i++ + x += b << 42 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 42 + + b = uint64(buf[i]) + i++ + x += b << 49 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 49 + + b = uint64(buf[i]) + i++ + x += b << 56 + if b&0x80 == 0 { + goto done + } + x -= 0x80 << 56 + + b = uint64(buf[i]) + i++ + x += b << 63 + if b&0x80 == 0 { + goto done + } + // x -= 0x80 << 63 // Always zero. + + return 0, errOverflow + +done: + p.index = i + return x, nil +} + +// DecodeFixed64 reads a 64-bit integer from the Buffer. +// This is the format for the +// fixed64, sfixed64, and double protocol buffer types. +func (p *Buffer) DecodeFixed64() (x uint64, err error) { + // x, err already 0 + i := p.index + 8 + if i < 0 || i > len(p.buf) { + err = io.ErrUnexpectedEOF + return + } + p.index = i + + x = uint64(p.buf[i-8]) + x |= uint64(p.buf[i-7]) << 8 + x |= uint64(p.buf[i-6]) << 16 + x |= uint64(p.buf[i-5]) << 24 + x |= uint64(p.buf[i-4]) << 32 + x |= uint64(p.buf[i-3]) << 40 + x |= uint64(p.buf[i-2]) << 48 + x |= uint64(p.buf[i-1]) << 56 + return +} + +// DecodeFixed32 reads a 32-bit integer from the Buffer. +// This is the format for the +// fixed32, sfixed32, and float protocol buffer types. +func (p *Buffer) DecodeFixed32() (x uint64, err error) { + // x, err already 0 + i := p.index + 4 + if i < 0 || i > len(p.buf) { + err = io.ErrUnexpectedEOF + return + } + p.index = i + + x = uint64(p.buf[i-4]) + x |= uint64(p.buf[i-3]) << 8 + x |= uint64(p.buf[i-2]) << 16 + x |= uint64(p.buf[i-1]) << 24 + return +} + +// DecodeZigzag64 reads a zigzag-encoded 64-bit integer +// from the Buffer. +// This is the format used for the sint64 protocol buffer type. +func (p *Buffer) DecodeZigzag64() (x uint64, err error) { + x, err = p.DecodeVarint() + if err != nil { + return + } + x = (x >> 1) ^ uint64((int64(x&1)<<63)>>63) + return +} + +// DecodeZigzag32 reads a zigzag-encoded 32-bit integer +// from the Buffer. +// This is the format used for the sint32 protocol buffer type. +func (p *Buffer) DecodeZigzag32() (x uint64, err error) { + x, err = p.DecodeVarint() + if err != nil { + return + } + x = uint64((uint32(x) >> 1) ^ uint32((int32(x&1)<<31)>>31)) + return +} + +// DecodeRawBytes reads a count-delimited byte buffer from the Buffer. +// This is the format used for the bytes protocol buffer +// type and for embedded messages. +func (p *Buffer) DecodeRawBytes(alloc bool) (buf []byte, err error) { + n, err := p.DecodeVarint() + if err != nil { + return nil, err + } + + nb := int(n) + if nb < 0 { + return nil, fmt.Errorf("proto: bad byte length %d", nb) + } + end := p.index + nb + if end < p.index || end > len(p.buf) { + return nil, io.ErrUnexpectedEOF + } + + if !alloc { + // todo: check if can get more uses of alloc=false + buf = p.buf[p.index:end] + p.index += nb + return + } + + buf = make([]byte, nb) + copy(buf, p.buf[p.index:]) + p.index += nb + return +} + +// DecodeStringBytes reads an encoded string from the Buffer. +// This is the format used for the proto2 string type. +func (p *Buffer) DecodeStringBytes() (s string, err error) { + buf, err := p.DecodeRawBytes(false) + if err != nil { + return + } + return string(buf), nil +} + +// Unmarshaler is the interface representing objects that can +// unmarshal themselves. The argument points to data that may be +// overwritten, so implementations should not keep references to the +// buffer. +// Unmarshal implementations should not clear the receiver. +// Any unmarshaled data should be merged into the receiver. +// Callers of Unmarshal that do not want to retain existing data +// should Reset the receiver before calling Unmarshal. +type Unmarshaler interface { + Unmarshal([]byte) error +} + +// newUnmarshaler is the interface representing objects that can +// unmarshal themselves. The semantics are identical to Unmarshaler. +// +// This exists to support protoc-gen-go generated messages. +// The proto package will stop type-asserting to this interface in the future. +// +// DO NOT DEPEND ON THIS. +type newUnmarshaler interface { + XXX_Unmarshal([]byte) error +} + +// Unmarshal parses the protocol buffer representation in buf and places the +// decoded result in pb. If the struct underlying pb does not match +// the data in buf, the results can be unpredictable. +// +// Unmarshal resets pb before starting to unmarshal, so any +// existing data in pb is always removed. Use UnmarshalMerge +// to preserve and append to existing data. +func Unmarshal(buf []byte, pb Message) error { + pb.Reset() + if u, ok := pb.(newUnmarshaler); ok { + return u.XXX_Unmarshal(buf) + } + if u, ok := pb.(Unmarshaler); ok { + return u.Unmarshal(buf) + } + return NewBuffer(buf).Unmarshal(pb) +} + +// UnmarshalMerge parses the protocol buffer representation in buf and +// writes the decoded result to pb. If the struct underlying pb does not match +// the data in buf, the results can be unpredictable. +// +// UnmarshalMerge merges into existing data in pb. +// Most code should use Unmarshal instead. +func UnmarshalMerge(buf []byte, pb Message) error { + if u, ok := pb.(newUnmarshaler); ok { + return u.XXX_Unmarshal(buf) + } + if u, ok := pb.(Unmarshaler); ok { + // NOTE: The history of proto have unfortunately been inconsistent + // whether Unmarshaler should or should not implicitly clear itself. + // Some implementations do, most do not. + // Thus, calling this here may or may not do what people want. + // + // See https://github.com/golang/protobuf/issues/424 + return u.Unmarshal(buf) + } + return NewBuffer(buf).Unmarshal(pb) +} + +// DecodeMessage reads a count-delimited message from the Buffer. +func (p *Buffer) DecodeMessage(pb Message) error { + enc, err := p.DecodeRawBytes(false) + if err != nil { + return err + } + return NewBuffer(enc).Unmarshal(pb) +} + +// DecodeGroup reads a tag-delimited group from the Buffer. +// StartGroup tag is already consumed. This function consumes +// EndGroup tag. +func (p *Buffer) DecodeGroup(pb Message) error { + b := p.buf[p.index:] + x, y := findEndGroup(b) + if x < 0 { + return io.ErrUnexpectedEOF + } + err := Unmarshal(b[:x], pb) + p.index += y + return err +} + +// Unmarshal parses the protocol buffer representation in the +// Buffer and places the decoded result in pb. If the struct +// underlying pb does not match the data in the buffer, the results can be +// unpredictable. +// +// Unlike proto.Unmarshal, this does not reset pb before starting to unmarshal. +func (p *Buffer) Unmarshal(pb Message) error { + // If the object can unmarshal itself, let it. + if u, ok := pb.(newUnmarshaler); ok { + err := u.XXX_Unmarshal(p.buf[p.index:]) + p.index = len(p.buf) + return err + } + if u, ok := pb.(Unmarshaler); ok { + // NOTE: The history of proto have unfortunately been inconsistent + // whether Unmarshaler should or should not implicitly clear itself. + // Some implementations do, most do not. + // Thus, calling this here may or may not do what people want. + // + // See https://github.com/golang/protobuf/issues/424 + err := u.Unmarshal(p.buf[p.index:]) + p.index = len(p.buf) + return err + } + + // Slow workaround for messages that aren't Unmarshalers. + // This includes some hand-coded .pb.go files and + // bootstrap protos. + // TODO: fix all of those and then add Unmarshal to + // the Message interface. Then: + // The cast above and code below can be deleted. + // The old unmarshaler can be deleted. + // Clients can call Unmarshal directly (can already do that, actually). + var info InternalMessageInfo + err := info.Unmarshal(pb, p.buf[p.index:]) + p.index = len(p.buf) + return err +} |