mirror of
https://github.com/prometheus/prometheus
synced 2024-12-23 23:13:11 +00:00
3d8826a3d4
* MultiError: Refactored MultiError for more concise and safe usage. * Less lines * Goland IDE was marking every usage of old MultiError "potential nil" error * It was easy to forgot using Err() when error was returned, now it's safely assured on compile time. NOTE: Potentially I would rename package to merrors. (: In different PR. Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com> * Addressed review comments. Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com> * Addressed comments. Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com> * Fix after rebase. Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>
90 lines
2.3 KiB
Go
90 lines
2.3 KiB
Go
// Copyright 2016 The etcd Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package errors
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
// multiError type allows combining multiple errors into one.
|
|
type multiError []error
|
|
|
|
// NewMulti returns multiError with provided errors added if not nil.
|
|
func NewMulti(errs ...error) multiError { // nolint:golint
|
|
m := multiError{}
|
|
m.Add(errs...)
|
|
return m
|
|
}
|
|
|
|
// Add adds single or many errors to the error list. Each error is added only if not nil.
|
|
// If the error is a nonNilMultiError type, the errors inside nonNilMultiError are added to the main multiError.
|
|
func (es *multiError) Add(errs ...error) {
|
|
for _, err := range errs {
|
|
if err == nil {
|
|
continue
|
|
}
|
|
if merr, ok := err.(nonNilMultiError); ok {
|
|
*es = append(*es, merr.errs...)
|
|
continue
|
|
}
|
|
*es = append(*es, err)
|
|
}
|
|
}
|
|
|
|
// Err returns the error list as an error or nil if it is empty.
|
|
func (es multiError) Err() error {
|
|
if len(es) == 0 {
|
|
return nil
|
|
}
|
|
return nonNilMultiError{errs: es}
|
|
}
|
|
|
|
// nonNilMultiError implements the error interface, and it represents
|
|
// multiError with at least one error inside it.
|
|
// This type is needed to make sure that nil is returned when no error is combined in multiError for err != nil
|
|
// check to work.
|
|
type nonNilMultiError struct {
|
|
errs multiError
|
|
}
|
|
|
|
// Error returns a concatenated string of the contained errors.
|
|
func (es nonNilMultiError) Error() string {
|
|
var buf bytes.Buffer
|
|
|
|
if len(es.errs) > 1 {
|
|
fmt.Fprintf(&buf, "%d errors: ", len(es.errs))
|
|
}
|
|
|
|
for i, err := range es.errs {
|
|
if i != 0 {
|
|
buf.WriteString("; ")
|
|
}
|
|
buf.WriteString(err.Error())
|
|
}
|
|
|
|
return buf.String()
|
|
}
|
|
|
|
// CloseAll closes all given closers while recording error in MultiError.
|
|
func CloseAll(cs []io.Closer) error {
|
|
errs := NewMulti()
|
|
for _, c := range cs {
|
|
errs.Add(c.Close())
|
|
}
|
|
return errs.Err()
|
|
}
|