klog/util.go

111 lines
2.6 KiB
Go

package klog
import (
"bytes"
"fmt"
"io/ioutil"
"runtime"
)
func caller(depth int) string {
_, file, line, _ := runtime.Caller(depth)
short := file
for i := len(file) - 1; i > 0; i-- {
if file[i] == '/' {
short = file[i+1:]
break
}
}
return fmt.Sprintf("%s:%d", short, line)
}
func stack() string {
buf := make([]byte, 1024)
for {
n := runtime.Stack(buf, false)
if n < len(buf) {
return string(buf[:n])
}
buf = make([]byte, 2*len(buf))
}
}
func getAllOffsprings(l *Logger) []*Logger {
if l.subs == nil || len(l.subs) == 0 {
return []*Logger{l}
}
loggers := []*Logger{}
for i := range l.subs {
loggers = append(loggers, getAllOffsprings(l.subs[i])...)
}
return loggers
}
var (
dunno = []byte("???")
centerDot = []byte("·")
dot = []byte(".")
slash = []byte("/")
)
// Stack returns a nicely formatted stack frame, skipping skip frames.
func Stack(skip int) []byte {
buf := new(bytes.Buffer) // the returned data
// As we loop, we open files and read them. These variables record the currently
// loaded file.
var lines [][]byte
var lastFile string
for i := skip; ; i++ { // Skip the expected number of frames
pc, file, line, ok := runtime.Caller(i)
if !ok {
break
}
// Print this much at least. If we can't find the source, it won't show.
fmt.Fprintf(buf, "%s:%d (0x%x)\n", file, line, pc)
if file != lastFile {
data, err := ioutil.ReadFile(file)
if err != nil {
continue
}
lines = bytes.Split(data, []byte{'\n'})
lastFile = file
}
fmt.Fprintf(buf, "\t%s: %s\n", function(pc), source(lines, line))
}
return buf.Bytes()
}
// function returns, if possible, the name of the function containing the PC.
func function(pc uintptr) []byte {
fn := runtime.FuncForPC(pc)
if fn == nil {
return dunno
}
name := []byte(fn.Name())
// The name includes the path name to the package, which is unnecessary
// since the file name is already included. Plus, it has center dots.
// That is, we see
// runtime/debug.*T·ptrmethod
// and want
// *T.ptrmethod
// Also the package path might contains dot (e.g. code.google.com/...),
// so first eliminate the path prefix
if lastSlash := bytes.LastIndex(name, slash); lastSlash >= 0 {
name = name[lastSlash+1:]
}
if period := bytes.Index(name, dot); period >= 0 {
name = name[period+1:]
}
name = bytes.Replace(name, centerDot, dot, -1)
return name
}
// source returns a space-trimmed slice of the n'th line.
func source(lines [][]byte, n int) []byte {
n-- // in stack trace, lines are 1-indexed but our array is 0-indexed
if n < 0 || n >= len(lines) {
return dunno
}
return bytes.TrimSpace(lines[n])
}