-
Notifications
You must be signed in to change notification settings - Fork 269
/
limit.go
92 lines (81 loc) · 2.47 KB
/
limit.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
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
// Copyright 2020-2023 Buf Technologies, Inc.
//
// 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 storage
import (
"context"
"go.uber.org/atomic"
)
// LimitWriteBucket returns a [WriteBucket] that writes to [writeBucket]
// but stops with an error after [limit] bytes are written.
//
// The error can be checked using [IsWriteLimitReached].
//
// A negative [limit] is same as 0 limit.
func LimitWriteBucket(writeBucket WriteBucket, limit int) WriteBucket {
if limit < 0 {
limit = 0
}
return newLimitedWriteBucket(writeBucket, int64(limit))
}
type limitedWriteBucket struct {
WriteBucket
currentSize *atomic.Int64
limit int64
}
func newLimitedWriteBucket(bucket WriteBucket, limit int64) *limitedWriteBucket {
return &limitedWriteBucket{
WriteBucket: bucket,
currentSize: atomic.NewInt64(0),
limit: limit,
}
}
func (w *limitedWriteBucket) Put(ctx context.Context, path string, opts ...PutOption) (WriteObjectCloser, error) {
writeObjectCloser, err := w.WriteBucket.Put(ctx, path, opts...)
if err != nil {
return nil, err
}
return newLimitedWriteObjectCloser(writeObjectCloser, w.currentSize, w.limit), nil
}
type limitedWriteObjectCloser struct {
WriteObjectCloser
bucketSize *atomic.Int64
limit int64
}
func newLimitedWriteObjectCloser(
writeObjectCloser WriteObjectCloser,
bucketSize *atomic.Int64,
limit int64,
) *limitedWriteObjectCloser {
return &limitedWriteObjectCloser{
WriteObjectCloser: writeObjectCloser,
bucketSize: bucketSize,
limit: limit,
}
}
func (o *limitedWriteObjectCloser) Write(p []byte) (int, error) {
writeSize := int64(len(p))
newBucketSize := o.bucketSize.Add(writeSize)
if newBucketSize > o.limit {
o.bucketSize.Sub(writeSize)
return 0, &errWriteLimitReached{
Limit: o.limit,
ExceedingBy: newBucketSize - o.limit,
}
}
writtenSize, err := o.WriteObjectCloser.Write(p)
if int64(writtenSize) < writeSize {
o.bucketSize.Sub(writeSize - int64(writtenSize))
}
return writtenSize, err
}