介绍不同语言的错误处理机制:
Error handling patterns
Musings about error handling mechanisms in programming languages
我的项目中 main调func1，func1调取func2...
这样就会呈现很多的 if err != nil { log.Printf()} , 在Kibana上查看时会搜到多条日志, 须要逐级定位, 确定谬误抛出的点
心愿只有一条, 能清晰看到整个堆栈调用信息
应用log.xxxx办法:
package mainimport ( "fmt" "log" "strconv" "time")func init() { log.SetFlags(log.Lshortfile | log.LstdFlags)}func main() { str := "123a" rs, err := func1(str) if err != nil { log.Printf("err is (%+v)\n", err) return } fmt.Println("最终后果为:", rs)}func func1(str string) (int, error) { b, err := func2() if err != nil { log.Printf("There is func11111, func2 err(%+v)\n", err) } if b == false { strInt, err := strconv.Atoi(str) if err != nil { log.Printf("There is func11111, err(%+v)\n", err) } return strInt, err } return 0, nil}func func2() (bool, error) { now := time.Now().Unix() endTimeStr := "2021-08-06 20:00:0000" endtime, err := time.ParseInLocation("2006-01-02 15:04:05", endTimeStr, time.Local) if err != nil { log.Printf("There is func22222, err(%+v)\n", err) return false, err } if endtime.Unix() > now { return true, nil } return false, nil}执行后果:
2021/06/07 21:52:56 vs.go:56: There is func22222, err(parsing time "2021-08-06 20:00:0000": extra text: "00")2021/06/07 21:52:56 vs.go:33: There is func11111, func2 err(parsing time "2021-08-06 20:00:0000": extra text: "00")2021/06/07 21:52:56 vs.go:40: There is func11111, err(strconv.Atoi: parsing "123a": invalid syntax)2021/06/07 21:52:56 vs.go:20: err is (strconv.Atoi: parsing "123a": invalid syntax)应用errors.Wrapf办法:
package mainimport ( "fmt" "github.com/pkg/errors" "strconv" "time")func main() { str := "123a" rs, err := func1(str) if err != nil { fmt.Printf("err: %+v\n", err) //fmt.Println("err:", lastErr) //必须%+v才会打印残缺堆栈信息,否则只打印错误信息 return } fmt.Println("最终后果为:", rs)}func func1(str string) (int, error) { b, err := func2() if err != nil { err = errors.Wrapf(err, "There is func11111, func2 err, b is(%b) \n", b) } if b == false { var strInt int strInt, err = strconv.Atoi(str) if err != nil { err = errors.Wrapf(err, "There is func11111,str is(%s)\n", str) } return strInt, err } return 0, nil}func func2() (bool, error) { now := time.Now().Unix() endTimeStr := "2021-08-06 20:00:0000" endtime, err := time.ParseInLocation("2006-01-02 15:04:05", endTimeStr, time.Local) if err != nil { err = errors.Wrapf(err, "There is func22222,endTimeStr is(%s)\n", endTimeStr) return false, err } if endtime.Unix() > now { return true, nil } return false, nil}执行:
err: strconv.Atoi: parsing "123a": invalid syntaxThere is func11111,str is(123a)main.func1 /Users/fliter/go/src/shuang/llog/1.go:39main.main /Users/fliter/go/src/shuang/llog/1.go:13runtime.main /usr/local/Cellar/go/1.16.3/libexec/src/runtime/proc.go:225runtime.goexit /usr/local/Cellar/go/1.16.3/libexec/src/runtime/asm_amd64.s:1371留神赋值这步, 必不可少！
有一个问题, 即对于f1调f2,f2调f3这种, 如果f3产生error, 能够逐级将error抛出.
但如果一个办法里有两个error, 则第二条会笼罩掉第一条,如上 err = errors.Wrapf(err, "There is func11111, func2 err, b is(%b) \n", b)这一条就被笼罩了
// Wrapf returns an error annotating err with a stack trace// at the point Wrapf is called, and the format specifier.// If err is nil, Wrapf returns nil.func Wrapf(err error, format string, args ...interface{}) error { if err == nil { return nil } err = &withMessage{ cause: err, msg: fmt.Sprintf(format, args...), } return &withStack{ err, callers(), }}func callers() *stack { const depth = 32 var pcs [depth]uintptr n := runtime.Callers(3, pcs[:]) var st stack = pcs[0:n] return &st}// Callers fills the slice pc with the return program counters of function invocations// on the calling goroutine's stack. The argument skip is the number of stack frames// to skip before recording in pc, with 0 identifying the frame for Callers itself and// 1 identifying the caller of Callers.// It returns the number of entries written to pc.//// To translate these PCs into symbolic information such as function// names and line numbers, use CallersFrames. CallersFrames accounts// for inlined functions and adjusts the return program counters into// call program counters. Iterating over the returned slice of PCs// directly is discouraged, as is using FuncForPC on any of the// returned PCs, since these cannot account for inlining or return// program counter adjustment.func Callers(skip int, pc []uintptr) int { // runtime.callers uses pc.array==nil as a signal // to print a stack trace. Pick off 0-length pc here // so that we don't let a nil pc slice get to it. if len(pc) == 0 { return 0 } return callers(skip, pc)}func callers(skip int, pcbuf []uintptr) int { sp := getcallersp() pc := getcallerpc() gp := getg() var n int systemstack(func() { n = gentraceback(pc, sp, 0, gp, skip, &pcbuf[0], len(pcbuf), nil, nil, 0) }) return n}参考:
golang 打印error的堆栈信息
Go错误处理最佳实际
本文由mdnice多平台公布