/
exit_events.go
97 lines (80 loc) · 1.81 KB
/
exit_events.go
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package grouper
import (
"fmt"
"sync"
)
/*
An ExitEvent occurs every time an invoked member exits.
*/
type ExitEvent struct {
Member Member
Err error
}
type exitEventChannel chan ExitEvent
func newExitEventChannel(bufferSize int) exitEventChannel {
return make(exitEventChannel, bufferSize)
}
type exitEventBroadcaster struct {
channels []exitEventChannel
buffer slidingBuffer
bufferSize int
lock *sync.Mutex
}
func newExitEventBroadcaster(bufferSize int) *exitEventBroadcaster {
return &exitEventBroadcaster{
channels: make([]exitEventChannel, 0),
buffer: newSlidingBuffer(bufferSize),
bufferSize: bufferSize,
lock: new(sync.Mutex),
}
}
func (b *exitEventBroadcaster) Attach() exitEventChannel {
b.lock.Lock()
defer b.lock.Unlock()
channel := newExitEventChannel(b.bufferSize)
b.buffer.Range(func(event interface{}) {
channel <- event.(ExitEvent)
})
if b.channels != nil {
b.channels = append(b.channels, channel)
} else {
close(channel)
}
return channel
}
func (b *exitEventBroadcaster) Broadcast(exit ExitEvent) {
b.lock.Lock()
defer b.lock.Unlock()
b.buffer.Append(exit)
for _, exitChan := range b.channels {
exitChan <- exit
}
}
func (b *exitEventBroadcaster) Close() {
b.lock.Lock()
defer b.lock.Unlock()
for _, channel := range b.channels {
close(channel)
}
b.channels = nil
}
type ErrorTrace []ExitEvent
func (trace ErrorTrace) Error() string {
msg := "Exit trace for group:\n"
for _, exit := range trace {
if exit.Err == nil {
msg += fmt.Sprintf("%s exited with nil\n", exit.Member.Name)
} else {
msg += fmt.Sprintf("%s exited with error: %s\n", exit.Member.Name, exit.Err.Error())
}
}
return msg
}
func (trace ErrorTrace) ErrorOrNil() error {
for _, exit := range trace {
if exit.Err != nil {
return trace
}
}
return nil
}