forked from TrueCloudLab/distribution
90 lines
2.1 KiB
Go
90 lines
2.1 KiB
Go
// Package errors provides errors that have stack-traces.
|
|
package errors
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"reflect"
|
|
"runtime"
|
|
)
|
|
|
|
// The maximum number of stackframes on any error.
|
|
var MaxStackDepth = 50
|
|
|
|
// Error is an error with an attached stacktrace. It can be used
|
|
// wherever the builtin error interface is expected.
|
|
type Error struct {
|
|
Err error
|
|
stack []uintptr
|
|
frames []StackFrame
|
|
}
|
|
|
|
// New makes an Error from the given value. If that value is already an
|
|
// error then it will be used directly, if not, it will be passed to
|
|
// fmt.Errorf("%v"). The skip parameter indicates how far up the stack
|
|
// to start the stacktrace. 0 is from the current call, 1 from its caller, etc.
|
|
func New(e interface{}, skip int) *Error {
|
|
var err error
|
|
|
|
switch e := e.(type) {
|
|
case *Error:
|
|
return e
|
|
case error:
|
|
err = e
|
|
default:
|
|
err = fmt.Errorf("%v", e)
|
|
}
|
|
|
|
stack := make([]uintptr, MaxStackDepth)
|
|
length := runtime.Callers(2+skip, stack[:])
|
|
return &Error{
|
|
Err: err,
|
|
stack: stack[:length],
|
|
}
|
|
}
|
|
|
|
// Errorf creates a new error with the given message. You can use it
|
|
// as a drop-in replacement for fmt.Errorf() to provide descriptive
|
|
// errors in return values.
|
|
func Errorf(format string, a ...interface{}) *Error {
|
|
return New(fmt.Errorf(format, a...), 1)
|
|
}
|
|
|
|
// Error returns the underlying error's message.
|
|
func (err *Error) Error() string {
|
|
return err.Err.Error()
|
|
}
|
|
|
|
// Stack returns the callstack formatted the same way that go does
|
|
// in runtime/debug.Stack()
|
|
func (err *Error) Stack() []byte {
|
|
buf := bytes.Buffer{}
|
|
|
|
for _, frame := range err.StackFrames() {
|
|
buf.WriteString(frame.String())
|
|
}
|
|
|
|
return buf.Bytes()
|
|
}
|
|
|
|
// StackFrames returns an array of frames containing information about the
|
|
// stack.
|
|
func (err *Error) StackFrames() []StackFrame {
|
|
if err.frames == nil {
|
|
err.frames = make([]StackFrame, len(err.stack))
|
|
|
|
for i, pc := range err.stack {
|
|
err.frames[i] = NewStackFrame(pc)
|
|
}
|
|
}
|
|
|
|
return err.frames
|
|
}
|
|
|
|
// TypeName returns the type this error. e.g. *errors.stringError.
|
|
func (err *Error) TypeName() string {
|
|
if _, ok := err.Err.(uncaughtPanic); ok {
|
|
return "panic"
|
|
}
|
|
return reflect.TypeOf(err.Err).String()
|
|
}
|