blob: f7ec1ac59cb4783d3f824657f965ace713b722f4 [file] [log] [blame]
// 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 pprof
// A protobuf is a simple protocol buffer encoder.
type protobuf struct {
data []byte
tmp [16]byte
nest int
}
func (b *protobuf) varint(x uint64) {
for x >= 128 {
b.data = append(b.data, byte(x)|0x80)
x >>= 7
}
b.data = append(b.data, byte(x))
}
func (b *protobuf) length(tag int, len int) {
b.varint(uint64(tag)<<3 | 2)
b.varint(uint64(len))
}
func (b *protobuf) uint64(tag int, x uint64) {
// append varint to b.data
b.varint(uint64(tag)<<3 | 0)
b.varint(x)
}
func (b *protobuf) uint64s(tag int, x []uint64) {
if len(x) > 2 {
// Use packed encoding
n1 := len(b.data)
for _, u := range x {
b.varint(u)
}
n2 := len(b.data)
b.length(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 {
b.uint64(tag, u)
}
}
func (b *protobuf) uint64Opt(tag int, x uint64) {
if x == 0 {
return
}
b.uint64(tag, x)
}
func (b *protobuf) int64(tag int, x int64) {
u := uint64(x)
b.uint64(tag, u)
}
func (b *protobuf) int64Opt(tag int, x int64) {
if x == 0 {
return
}
b.int64(tag, x)
}
func (b *protobuf) int64s(tag int, x []int64) {
if len(x) > 2 {
// Use packed encoding
n1 := len(b.data)
for _, u := range x {
b.varint(uint64(u))
}
n2 := len(b.data)
b.length(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 {
b.int64(tag, u)
}
}
func (b *protobuf) string(tag int, x string) {
b.length(tag, len(x))
b.data = append(b.data, x...)
}
func (b *protobuf) strings(tag int, x []string) {
for _, s := range x {
b.string(tag, s)
}
}
func (b *protobuf) stringOpt(tag int, x string) {
if x == "" {
return
}
b.string(tag, x)
}
func (b *protobuf) bool(tag int, x bool) {
if x {
b.uint64(tag, 1)
} else {
b.uint64(tag, 0)
}
}
func (b *protobuf) boolOpt(tag int, x bool) {
if !x {
return
}
b.bool(tag, x)
}
type msgOffset int
func (b *protobuf) startMessage() msgOffset {
b.nest++
return msgOffset(len(b.data))
}
func (b *protobuf) endMessage(tag int, start msgOffset) {
n1 := int(start)
n2 := len(b.data)
b.length(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])
b.nest--
}