Mainflux.mainflux/pkg/errors/errors.go

115 lines
1.9 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
package errors
import (
"context"
"fmt"
"os"
"os/signal"
"syscall"
)
// Error specifies an API that must be fullfiled by error type.
type Error interface {
// Error implements the error interface.
Error() string
// Msg returns error message
Msg() string
// Err returns wrapped error
Err() Error
}
var _ Error = (*customError)(nil)
// customError represents a Mainflux error.
type customError struct {
msg string
err Error
}
func (ce *customError) Error() string {
if ce == nil {
return ""
}
if ce.err == nil {
return ce.msg
}
return ce.msg + " : " + ce.err.Error()
}
func (ce *customError) Msg() string {
return ce.msg
}
func (ce *customError) Err() Error {
return ce.err
}
// Contains inspects if e2 error is contained in any layer of e1 error.
func Contains(e1 error, e2 error) bool {
if e1 == nil || e2 == nil {
return e2 == e1
}
ce, ok := e1.(Error)
if ok {
if ce.Msg() == e2.Error() {
return true
}
return Contains(ce.Err(), e2)
}
return e1.Error() == e2.Error()
}
// Wrap returns an Error that wrap err with wrapper.
func Wrap(wrapper error, err error) error {
if wrapper == nil || err == nil {
return wrapper
}
if w, ok := wrapper.(Error); ok {
return &customError{
msg: w.Msg(),
err: cast(err),
}
}
return &customError{
msg: wrapper.Error(),
err: cast(err),
}
}
func cast(err error) Error {
if err == nil {
return nil
}
if e, ok := err.(Error); ok {
return e
}
return &customError{
msg: err.Error(),
err: nil,
}
}
// New returns an Error that formats as the given text.
func New(text string) Error {
return &customError{
msg: text,
err: nil,
}
}
func SignalHandler(ctx context.Context) error {
c := make(chan os.Signal, 2)
signal.Notify(c, syscall.SIGINT, syscall.SIGABRT)
select {
case sig := <-c:
return fmt.Errorf("%s", sig)
case <-ctx.Done():
return nil
}
}