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Diffstat (limited to '')
| -rw-r--r-- | src/internal/profile/proto.go | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/src/internal/profile/proto.go b/src/internal/profile/proto.go new file mode 100644 index 0000000..52cf1ef --- /dev/null +++ b/src/internal/profile/proto.go @@ -0,0 +1,363 @@ +// 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. + +// This file is a simple protocol buffer encoder and decoder. +// +// A protocol message must implement the message interface: +// decoder() []decoder +// encode(*buffer) +// +// The decode method returns a slice indexed by field number that gives the +// function to decode that field. +// The encode method encodes its receiver into the given buffer. +// +// The two methods are simple enough to be implemented by hand rather than +// by using a protocol compiler. +// +// See profile.go for examples of messages implementing this interface. +// +// There is no support for groups, message sets, or "has" bits. + +package profile + +import ( + "errors" + "fmt" +) + +type buffer struct { + field int + typ int + u64 uint64 + data []byte + tmp [16]byte +} + +type decoder func(*buffer, message) error + +type message interface { + decoder() []decoder + encode(*buffer) +} + +func marshal(m message) []byte { + var b buffer + m.encode(&b) + return b.data +} + +func encodeVarint(b *buffer, x uint64) { + for x >= 128 { + b.data = append(b.data, byte(x)|0x80) + x >>= 7 + } + b.data = append(b.data, byte(x)) +} + +func encodeLength(b *buffer, tag int, len int) { + encodeVarint(b, uint64(tag)<<3|2) + encodeVarint(b, uint64(len)) +} + +func encodeUint64(b *buffer, tag int, x uint64) { + // append varint to b.data + encodeVarint(b, uint64(tag)<<3|0) + encodeVarint(b, x) +} + +func encodeUint64s(b *buffer, tag int, x []uint64) { + if len(x) > 2 { + // Use packed encoding + n1 := len(b.data) + for _, u := range x { + encodeVarint(b, u) + } + n2 := len(b.data) + encodeLength(b, tag, n2-n1) + n3 := len(b.data) + copy(b.tmp[:], b.data[n2:n3]) + copy(b.data[n1+(n3-n2):], b.data[n1:n2]) + copy(b.data[n1:], b.tmp[:n3-n2]) + return + } + for _, u := range x { + encodeUint64(b, tag, u) + } +} + +func encodeUint64Opt(b *buffer, tag int, x uint64) { + if x == 0 { + return + } + encodeUint64(b, tag, x) +} + +func encodeInt64(b *buffer, tag int, x int64) { + u := uint64(x) + encodeUint64(b, tag, u) +} + +func encodeInt64Opt(b *buffer, tag int, x int64) { + if x == 0 { + return + } + encodeInt64(b, tag, x) +} + +func encodeInt64s(b *buffer, tag int, x []int64) { + if len(x) > 2 { + // Use packed encoding + n1 := len(b.data) + for _, u := range x { + encodeVarint(b, uint64(u)) + } + n2 := len(b.data) + encodeLength(b, tag, n2-n1) + n3 := len(b.data) + copy(b.tmp[:], b.data[n2:n3]) + copy(b.data[n1+(n3-n2):], b.data[n1:n2]) + copy(b.data[n1:], b.tmp[:n3-n2]) + return + } + for _, u := range x { + encodeInt64(b, tag, u) + } +} + +func encodeString(b *buffer, tag int, x string) { + encodeLength(b, tag, len(x)) + b.data = append(b.data, x...) +} + +func encodeStrings(b *buffer, tag int, x []string) { + for _, s := range x { + encodeString(b, tag, s) + } +} + +func encodeStringOpt(b *buffer, tag int, x string) { + if x == "" { + return + } + encodeString(b, tag, x) +} + +func encodeBool(b *buffer, tag int, x bool) { + if x { + encodeUint64(b, tag, 1) + } else { + encodeUint64(b, tag, 0) + } +} + +func encodeBoolOpt(b *buffer, tag int, x bool) { + if x == false { + return + } + encodeBool(b, tag, x) +} + +func encodeMessage(b *buffer, tag int, m message) { + n1 := len(b.data) + m.encode(b) + n2 := len(b.data) + encodeLength(b, tag, n2-n1) + n3 := len(b.data) + copy(b.tmp[:], b.data[n2:n3]) + copy(b.data[n1+(n3-n2):], b.data[n1:n2]) + copy(b.data[n1:], b.tmp[:n3-n2]) +} + +func unmarshal(data []byte, m message) (err error) { + b := buffer{data: data, typ: 2} + return decodeMessage(&b, m) +} + +func le64(p []byte) uint64 { + return uint64(p[0]) | uint64(p[1])<<8 | uint64(p[2])<<16 | uint64(p[3])<<24 | uint64(p[4])<<32 | uint64(p[5])<<40 | uint64(p[6])<<48 | uint64(p[7])<<56 +} + +func le32(p []byte) uint32 { + return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24 +} + +func decodeVarint(data []byte) (uint64, []byte, error) { + var i int + var u uint64 + for i = 0; ; i++ { + if i >= 10 || i >= len(data) { + return 0, nil, errors.New("bad varint") + } + u |= uint64(data[i]&0x7F) << uint(7*i) + if data[i]&0x80 == 0 { + return u, data[i+1:], nil + } + } +} + +func decodeField(b *buffer, data []byte) ([]byte, error) { + x, data, err := decodeVarint(data) + if err != nil { + return nil, err + } + b.field = int(x >> 3) + b.typ = int(x & 7) + b.data = nil + b.u64 = 0 + switch b.typ { + case 0: + b.u64, data, err = decodeVarint(data) + if err != nil { + return nil, err + } + case 1: + if len(data) < 8 { + return nil, errors.New("not enough data") + } + b.u64 = le64(data[:8]) + data = data[8:] + case 2: + var n uint64 + n, data, err = decodeVarint(data) + if err != nil { + return nil, err + } + if n > uint64(len(data)) { + return nil, errors.New("too much data") + } + b.data = data[:n] + data = data[n:] + case 5: + if len(data) < 4 { + return nil, errors.New("not enough data") + } + b.u64 = uint64(le32(data[:4])) + data = data[4:] + default: + return nil, fmt.Errorf("unknown wire type: %d", b.typ) + } + + return data, nil +} + +func checkType(b *buffer, typ int) error { + if b.typ != typ { + return errors.New("type mismatch") + } + return nil +} + +func decodeMessage(b *buffer, m message) error { + if err := checkType(b, 2); err != nil { + return err + } + dec := m.decoder() + data := b.data + for len(data) > 0 { + // pull varint field# + type + var err error + data, err = decodeField(b, data) + if err != nil { + return err + } + if b.field >= len(dec) || dec[b.field] == nil { + continue + } + if err := dec[b.field](b, m); err != nil { + return err + } + } + return nil +} + +func decodeInt64(b *buffer, x *int64) error { + if err := checkType(b, 0); err != nil { + return err + } + *x = int64(b.u64) + return nil +} + +func decodeInt64s(b *buffer, x *[]int64) error { + if b.typ == 2 { + // Packed encoding + data := b.data + for len(data) > 0 { + var u uint64 + var err error + + if u, data, err = decodeVarint(data); err != nil { + return err + } + *x = append(*x, int64(u)) + } + return nil + } + var i int64 + if err := decodeInt64(b, &i); err != nil { + return err + } + *x = append(*x, i) + return nil +} + +func decodeUint64(b *buffer, x *uint64) error { + if err := checkType(b, 0); err != nil { + return err + } + *x = b.u64 + return nil +} + +func decodeUint64s(b *buffer, x *[]uint64) error { + if b.typ == 2 { + data := b.data + // Packed encoding + for len(data) > 0 { + var u uint64 + var err error + + if u, data, err = decodeVarint(data); err != nil { + return err + } + *x = append(*x, u) + } + return nil + } + var u uint64 + if err := decodeUint64(b, &u); err != nil { + return err + } + *x = append(*x, u) + return nil +} + +func decodeString(b *buffer, x *string) error { + if err := checkType(b, 2); err != nil { + return err + } + *x = string(b.data) + return nil +} + +func decodeStrings(b *buffer, x *[]string) error { + var s string + if err := decodeString(b, &s); err != nil { + return err + } + *x = append(*x, s) + return nil +} + +func decodeBool(b *buffer, x *bool) error { + if err := checkType(b, 0); err != nil { + return err + } + if int64(b.u64) == 0 { + *x = false + } else { + *x = true + } + return nil +} |