| // Copyright 2017 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package profiler |
| |
| import ( |
| "bytes" |
| "regexp" |
| "runtime" |
| "strings" |
| |
| "github.com/google/pprof/profile" |
| ) |
| |
| var shouldAssumeSymbolized = isSymbolizedGoVersion(runtime.Version()) |
| |
| type function interface { |
| Name() string |
| FileLine(pc uintptr) (string, int) |
| } |
| |
| // funcForPC is a wrapper for runtime.FuncForPC. Defined as var for testing. |
| var funcForPC = func(pc uintptr) function { |
| return runtime.FuncForPC(pc) |
| } |
| |
| // parseAndSymbolize parses a profile from a buffer, symbolizes it |
| // if it's not yet symbolized, and writes the profile back as a |
| // gzip-compressed marshaled protobuf. |
| func parseAndSymbolize(data *bytes.Buffer) error { |
| p, err := profile.ParseData(data.Bytes()) |
| if err != nil { |
| return err |
| } |
| |
| // Do nothing if the profile is already symbolized. |
| if symbolized(p) { |
| return nil |
| } |
| // Clear the profile functions to avoid creating duplicates. |
| p.Function = nil |
| symbolize(p) |
| data.Reset() |
| return p.Write(data) |
| } |
| |
| // isSymbolizedGoVersion returns true if Go version equals to or is |
| // higher than Go 1.9. Starting Go 1.9 the profiles are symbolized |
| // by runtime/pprof. |
| func isSymbolizedGoVersion(goVersion string) bool { |
| r, err := regexp.Compile(`go(1\.9|1\.[1-9][0-9]|[2-9]).*`) |
| if err == nil && r.MatchString(goVersion) { |
| return true |
| } |
| return false |
| } |
| |
| // symbolized checks if all locations have symbolized function |
| // information. |
| func symbolized(p *profile.Profile) bool { |
| for _, l := range p.Location { |
| if len(l.Line) == 0 || l.Line[0].Function == nil { |
| return false |
| } |
| } |
| return true |
| } |
| |
| func symbolize(p *profile.Profile) { |
| fns := profileFunctionMap{} |
| for _, l := range p.Location { |
| pc := uintptr(l.Address) |
| f := funcForPC(pc) |
| if f == nil { |
| continue |
| } |
| file, lineno := f.FileLine(pc) |
| l.Line = []profile.Line{ |
| { |
| Function: fns.findOrAddFunction(f.Name(), file, p), |
| Line: int64(lineno), |
| }, |
| } |
| } |
| // Trim runtime functions. Always hide runtime.goexit. Other runtime |
| // functions are only hidden for heap profile when they appear at the beginning. |
| isHeapProfile := p.PeriodType != nil && p.PeriodType.Type == "space" |
| for _, s := range p.Sample { |
| show := !isHeapProfile |
| var i int |
| for _, l := range s.Location { |
| if len(l.Line) > 0 && l.Line[0].Function != nil { |
| name := l.Line[0].Function.Name |
| if name == "runtime.goexit" || !show && strings.HasPrefix(name, "runtime.") { |
| continue |
| } |
| } |
| show = true |
| s.Location[i] = l |
| i++ |
| } |
| // If all locations of a sample are trimmed, keep the root location. |
| if i == 0 && len(s.Location) > 0 { |
| s.Location[0] = s.Location[len(s.Location)-1] |
| i = 1 |
| } |
| s.Location = s.Location[:i] |
| } |
| } |
| |
| type profileFunctionMap map[profile.Function]*profile.Function |
| |
| func (fns profileFunctionMap) findOrAddFunction(name, filename string, p *profile.Profile) *profile.Function { |
| f := profile.Function{ |
| Name: name, |
| SystemName: name, |
| Filename: filename, |
| } |
| if fp := fns[f]; fp != nil { |
| return fp |
| } |
| fp := new(profile.Function) |
| fns[f] = fp |
| |
| *fp = f |
| fp.ID = uint64(len(p.Function) + 1) |
| p.Function = append(p.Function, fp) |
| return fp |
| } |