clash/common/batch/batch.go

106 lines
1.6 KiB
Go

package batch
import (
"context"
"sync"
)
type Option = func(b *Batch)
type Result struct {
Value interface{}
Err error
}
type Error struct {
Key string
Err error
}
func WithConcurrencyNum(n int) Option {
return func(b *Batch) {
q := make(chan struct{}, n)
for i := 0; i < n; i++ {
q <- struct{}{}
}
b.queue = q
}
}
// Batch similar to errgroup, but can control the maximum number of concurrent
type Batch struct {
result map[string]Result
queue chan struct{}
wg sync.WaitGroup
mux sync.Mutex
err *Error
once sync.Once
cancel func()
}
func (b *Batch) Go(key string, fn func() (interface{}, error)) {
b.wg.Add(1)
go func() {
defer b.wg.Done()
if b.queue != nil {
<-b.queue
defer func() {
b.queue <- struct{}{}
}()
}
value, err := fn()
if err != nil {
b.once.Do(func() {
b.err = &Error{key, err}
if b.cancel != nil {
b.cancel()
}
})
}
ret := Result{value, err}
b.mux.Lock()
defer b.mux.Unlock()
b.result[key] = ret
}()
}
func (b *Batch) Wait() *Error {
b.wg.Wait()
if b.cancel != nil {
b.cancel()
}
return b.err
}
func (b *Batch) WaitAndGetResult() (map[string]Result, *Error) {
err := b.Wait()
return b.Result(), err
}
func (b *Batch) Result() map[string]Result {
b.mux.Lock()
defer b.mux.Unlock()
copy := map[string]Result{}
for k, v := range b.result {
copy[k] = v
}
return copy
}
func New(ctx context.Context, opts ...Option) (*Batch, context.Context) {
ctx, cancel := context.WithCancel(ctx)
b := &Batch{
result: map[string]Result{},
}
for _, o := range opts {
o(b)
}
b.cancel = cancel
return b, ctx
}