| // 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 |
| } |