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path: root/src/cmd/pprof/internal/profile/proto.go
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Diffstat (limited to 'src/cmd/pprof/internal/profile/proto.go')
-rw-r--r--src/cmd/pprof/internal/profile/proto.go298
1 files changed, 298 insertions, 0 deletions
diff --git a/src/cmd/pprof/internal/profile/proto.go b/src/cmd/pprof/internal/profile/proto.go
new file mode 100644
index 000000000..475cf564f
--- /dev/null
+++ b/src/cmd/pprof/internal/profile/proto.go
@@ -0,0 +1,298 @@
+// 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"
+
+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) {
+ 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 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, errors.New("unknown type: " + string(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 {
+ 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 {
+ 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
+}