1 files changed, 106 insertions, 0 deletions
diff --git a/src/runtime/pprof/internal/protopprof/protopprof.go b/src/runtime/pprof/internal/protopprof/protopprof.go
new file mode 100644
index 0000000000..6d799d921f
--- /dev/null
+++ b/src/runtime/pprof/internal/protopprof/protopprof.go
@@ -0,0 +1,106 @@
+// Copyright 2016 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 protopprof converts the runtime's raw profile logs
+// to Profile structs containing a representation of the pprof
+// protocol buffer profile format.
+package protopprof
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"time"
+	"unsafe"
+
+	"internal/pprof/profile"
+)
+
+// TranslateCPUProfile parses binary CPU profiling stack trace data
+// generated by runtime.CPUProfile() into a profile struct.
+func TranslateCPUProfile(b []byte, startTime time.Time) (*profile.Profile, error) {
+	const wordSize = unsafe.Sizeof(uintptr(0))
+	const minRawProfile = 5 * wordSize // Need a minimum of 5 words.
+	if uintptr(len(b)) < minRawProfile {
+		return nil, fmt.Errorf("truncated profile")
+	}
+	n := int(uintptr(len(b)) / wordSize)
+	data := ((*[1 << 28]uintptr)(unsafe.Pointer(&b[0])))[:n:n]
+	period := data[3]
+	data = data[5:] // skip header
+
+	// profile initialization taken from pprof tool
+	p := &profile.Profile{
+		Period:     int64(period) * 1000,
+		PeriodType: &profile.ValueType{Type: "cpu", Unit: "nanoseconds"},
+		SampleType: []*profile.ValueType{
+			{Type: "samples", Unit: "count"},
+			{Type: "cpu", Unit: "nanoseconds"},
+		},
+		TimeNanos:     int64(startTime.UnixNano()),
+		DurationNanos: time.Since(startTime).Nanoseconds(),
+	}
+	// Parse CPU samples from the profile.
+	locs := make(map[uint64]*profile.Location)
+	for len(b) > 0 {
+		if len(data) < 2 || uintptr(len(data)) < 2+data[1] {
+			return nil, fmt.Errorf("truncated profile")
+		}
+		count := data[0]
+		nstk := data[1]
+		fmt.Printf("count:%v nstk: %v\n", count, nstk)
+		if uintptr(len(data)) < 2+nstk {
+			return nil, fmt.Errorf("truncated profile")
+		}
+		stk := data[2 : 2+nstk]
+		data = data[2+nstk:]
+
+		if count == 0 && nstk == 1 && stk[0] == 0 {
+			// end of data marker
+			break
+		}
+
+		sloc := make([]*profile.Location, len(stk))
+		for i, addr := range stk {
+			addr := uint64(addr)
+			// Addresses from stack traces point to the next instruction after
+			// each call.  Adjust by -1 to land somewhere on the actual call
+			// (except for the leaf, which is not a call).
+			if i > 0 {
+				addr--
+			}
+			loc := locs[addr]
+			if loc == nil {
+				loc = &profile.Location{
+					ID:      uint64(len(p.Location) + 1),
+					Address: addr,
+				}
+				locs[addr] = loc
+				p.Location = append(p.Location, loc)
+			}
+			sloc[i] = loc
+		}
+		p.Sample = append(p.Sample, &profile.Sample{
+			Value:    []int64{int64(count), int64(count) * int64(p.Period)},
+			Location: sloc,
+		})
+	}
+
+	if runtime.GOOS == "linux" {
+		if err := addMappings(p); err != nil {
+			return nil, err
+		}
+	}
+	return p, nil
+}
+
+func addMappings(p *profile.Profile) error {
+	// Parse memory map from /proc/self/maps
+	f, err := os.Open("/proc/self/maps")
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	return p.ParseMemoryMap(f)
+}