/
fanout.go
49 lines (40 loc) · 1.12 KB
/
fanout.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
// Copyright 2023 The glassdb 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 concurr
import (
"context"
"golang.org/x/sync/errgroup"
)
func NewFanout(maxConcurrent int) Fanout {
return Fanout{
limit: maxConcurrent,
}
}
type Fanout struct {
limit int
}
func (o Fanout) Spawn(ctx context.Context, num int, f func(context.Context, int) error) Result {
g, ctx := errgroup.WithContext(ctx)
g.SetLimit(o.limit)
for i := 0; i < num; i++ {
i := i // https://golang.org/doc/faq#closures_and_goroutines
g.Go(func() error {
return f(ctx, i)
})
}
return g
}
type Result interface {
Wait() error
}