121 lines
2.7 KiB
Go
121 lines
2.7 KiB
Go
// Copyright (c) 2016 Matthias Neugebauer
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to deal
|
|
// in the Software without restriction, including without limitation the rights
|
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in all
|
|
// copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
// SOFTWARE.
|
|
|
|
package startstopper
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"sync"
|
|
)
|
|
|
|
// Group StartStopper together and run them as one.
|
|
type Group struct {
|
|
StartStopper
|
|
|
|
sss []StartStopper
|
|
}
|
|
|
|
// GroupError is the concrete error type returned by Group structs. It bundles
|
|
// the errors that could be returned by the StartStoppers.
|
|
type GroupError struct {
|
|
Errors []error
|
|
}
|
|
|
|
// Error implements the error interface.
|
|
func (g GroupError) Error() string {
|
|
var buffer bytes.Buffer
|
|
|
|
for _, err := range g.Errors {
|
|
if err != nil {
|
|
buffer.WriteString(err.Error())
|
|
buffer.WriteString(", ")
|
|
}
|
|
}
|
|
|
|
str := buffer.String()
|
|
return str[:len(str)-2]
|
|
}
|
|
|
|
// NewGroup creates a new group.
|
|
func NewGroup(sss []StartStopper) *Group {
|
|
group := &Group{sss: sss}
|
|
group.StartStopper = NewGo(RunnerFunc(group.run))
|
|
return group
|
|
}
|
|
|
|
func (g *Group) run(ctx context.Context, stopChan <-chan struct{}) error {
|
|
var once sync.Once
|
|
errorOccured := false
|
|
setErrorOccured := func() {
|
|
once.Do(func() {
|
|
errorOccured = true
|
|
})
|
|
}
|
|
|
|
groupErr := GroupError{
|
|
Errors: make([]error, len(g.sss)),
|
|
}
|
|
|
|
for i, ss := range g.sss {
|
|
groupErr.Errors[i] = ss.Start(ctx)
|
|
if groupErr.Errors[i] != nil {
|
|
setErrorOccured()
|
|
}
|
|
}
|
|
|
|
if errorOccured {
|
|
return groupErr
|
|
}
|
|
|
|
select {
|
|
case <-stopChan:
|
|
case <-ctx.Done():
|
|
}
|
|
|
|
var wg sync.WaitGroup
|
|
wg.Add(len(g.sss))
|
|
|
|
for _i, _ss := range g.sss {
|
|
i, ss := _i, _ss
|
|
|
|
go func() {
|
|
err := ss.Stop(ctx)
|
|
|
|
if err == nil {
|
|
err = ss.Err(ctx)
|
|
}
|
|
if err != nil {
|
|
setErrorOccured()
|
|
}
|
|
groupErr.Errors[i] = err
|
|
|
|
wg.Done()
|
|
}()
|
|
}
|
|
|
|
wg.Wait()
|
|
|
|
if errorOccured {
|
|
return groupErr
|
|
}
|
|
return nil
|
|
}
|