route/vendor/github.com/hashicorp/go-hclog/stacktrace.go

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2017-12-02 23:34:35 +00:00
// Copyright (c) 2016 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package hclog
import (
"bytes"
"runtime"
"strconv"
"strings"
"sync"
)
var (
_stacktraceIgnorePrefixes = []string{
"runtime.goexit",
"runtime.main",
}
_stacktracePool = sync.Pool{
New: func() interface{} {
return newProgramCounters(64)
},
}
)
// A stacktrace gathered by a previous call to log.Stacktrace. If passed
// to a logging function, the stacktrace will be appended.
type CapturedStacktrace string
// Gather a stacktrace of the current goroutine and return it to be passed
// to a logging function.
func Stacktrace() CapturedStacktrace {
return CapturedStacktrace(takeStacktrace())
}
func takeStacktrace() string {
programCounters := _stacktracePool.Get().(*programCounters)
defer _stacktracePool.Put(programCounters)
var buffer bytes.Buffer
for {
// Skip the call to runtime.Counters and takeStacktrace so that the
// program counters start at the caller of takeStacktrace.
n := runtime.Callers(2, programCounters.pcs)
if n < cap(programCounters.pcs) {
programCounters.pcs = programCounters.pcs[:n]
break
}
// Don't put the too-short counter slice back into the pool; this lets
// the pool adjust if we consistently take deep stacktraces.
programCounters = newProgramCounters(len(programCounters.pcs) * 2)
}
i := 0
frames := runtime.CallersFrames(programCounters.pcs)
for frame, more := frames.Next(); more; frame, more = frames.Next() {
if shouldIgnoreStacktraceFunction(frame.Function) {
continue
}
if i != 0 {
buffer.WriteByte('\n')
}
i++
buffer.WriteString(frame.Function)
buffer.WriteByte('\n')
buffer.WriteByte('\t')
buffer.WriteString(frame.File)
buffer.WriteByte(':')
buffer.WriteString(strconv.Itoa(int(frame.Line)))
}
return buffer.String()
}
func shouldIgnoreStacktraceFunction(function string) bool {
for _, prefix := range _stacktraceIgnorePrefixes {
if strings.HasPrefix(function, prefix) {
return true
}
}
return false
}
type programCounters struct {
pcs []uintptr
}
func newProgramCounters(size int) *programCounters {
return &programCounters{make([]uintptr, size)}
}