127 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			127 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			Go
		
	
	
	
// 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 zap
 | 
						|
 | 
						|
import (
 | 
						|
	"runtime"
 | 
						|
	"strings"
 | 
						|
	"sync"
 | 
						|
 | 
						|
	"go.uber.org/zap/internal/bufferpool"
 | 
						|
)
 | 
						|
 | 
						|
const _zapPackage = "go.uber.org/zap"
 | 
						|
 | 
						|
var (
 | 
						|
	_stacktracePool = sync.Pool{
 | 
						|
		New: func() interface{} {
 | 
						|
			return newProgramCounters(64)
 | 
						|
		},
 | 
						|
	}
 | 
						|
 | 
						|
	// We add "." and "/" suffixes to the package name to ensure we only match
 | 
						|
	// the exact package and not any package with the same prefix.
 | 
						|
	_zapStacktracePrefixes       = addPrefix(_zapPackage, ".", "/")
 | 
						|
	_zapStacktraceVendorContains = addPrefix("/vendor/", _zapStacktracePrefixes...)
 | 
						|
)
 | 
						|
 | 
						|
func takeStacktrace() string {
 | 
						|
	buffer := bufferpool.Get()
 | 
						|
	defer buffer.Free()
 | 
						|
	programCounters := _stacktracePool.Get().(*programCounters)
 | 
						|
	defer _stacktracePool.Put(programCounters)
 | 
						|
 | 
						|
	var numFrames int
 | 
						|
	for {
 | 
						|
		// Skip the call to runtime.Counters and takeStacktrace so that the
 | 
						|
		// program counters start at the caller of takeStacktrace.
 | 
						|
		numFrames = runtime.Callers(2, programCounters.pcs)
 | 
						|
		if numFrames < len(programCounters.pcs) {
 | 
						|
			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
 | 
						|
	skipZapFrames := true // skip all consecutive zap frames at the beginning.
 | 
						|
	frames := runtime.CallersFrames(programCounters.pcs[:numFrames])
 | 
						|
 | 
						|
	// Note: On the last iteration, frames.Next() returns false, with a valid
 | 
						|
	// frame, but we ignore this frame. The last frame is a a runtime frame which
 | 
						|
	// adds noise, since it's only either runtime.main or runtime.goexit.
 | 
						|
	for frame, more := frames.Next(); more; frame, more = frames.Next() {
 | 
						|
		if skipZapFrames && isZapFrame(frame.Function) {
 | 
						|
			continue
 | 
						|
		} else {
 | 
						|
			skipZapFrames = false
 | 
						|
		}
 | 
						|
 | 
						|
		if i != 0 {
 | 
						|
			buffer.AppendByte('\n')
 | 
						|
		}
 | 
						|
		i++
 | 
						|
		buffer.AppendString(frame.Function)
 | 
						|
		buffer.AppendByte('\n')
 | 
						|
		buffer.AppendByte('\t')
 | 
						|
		buffer.AppendString(frame.File)
 | 
						|
		buffer.AppendByte(':')
 | 
						|
		buffer.AppendInt(int64(frame.Line))
 | 
						|
	}
 | 
						|
 | 
						|
	return buffer.String()
 | 
						|
}
 | 
						|
 | 
						|
func isZapFrame(function string) bool {
 | 
						|
	for _, prefix := range _zapStacktracePrefixes {
 | 
						|
		if strings.HasPrefix(function, prefix) {
 | 
						|
			return true
 | 
						|
		}
 | 
						|
	}
 | 
						|
 | 
						|
	// We can't use a prefix match here since the location of the vendor
 | 
						|
	// directory affects the prefix. Instead we do a contains match.
 | 
						|
	for _, contains := range _zapStacktraceVendorContains {
 | 
						|
		if strings.Contains(function, contains) {
 | 
						|
			return true
 | 
						|
		}
 | 
						|
	}
 | 
						|
 | 
						|
	return false
 | 
						|
}
 | 
						|
 | 
						|
type programCounters struct {
 | 
						|
	pcs []uintptr
 | 
						|
}
 | 
						|
 | 
						|
func newProgramCounters(size int) *programCounters {
 | 
						|
	return &programCounters{make([]uintptr, size)}
 | 
						|
}
 | 
						|
 | 
						|
func addPrefix(prefix string, ss ...string) []string {
 | 
						|
	withPrefix := make([]string, len(ss))
 | 
						|
	for i, s := range ss {
 | 
						|
		withPrefix[i] = prefix + s
 | 
						|
	}
 | 
						|
	return withPrefix
 | 
						|
}
 |