-
Notifications
You must be signed in to change notification settings - Fork 264
/
util.go
49 lines (42 loc) · 1.42 KB
/
util.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 2020 The Dragonfly 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 util
import "math"
const (
// DefaultPieceSize 4M
DefaultPieceSize = 4 * 1024 * 1024
// DefaultPieceSizeLimit 15M
DefaultPieceSizeLimit = 15 * 1024 * 1024
)
// ComputePieceSize computes the piece size with specified fileLength.
//
// If the fileLength<0, which means failed to get fileLength
// and then use the DefaultPieceSize.
func ComputePieceSize(length int64) uint32 {
if length <= 200*1024*1024 {
return DefaultPieceSize
}
gapCount := length / int64(100*1024*1024)
mpSize := (gapCount-2)*1024*1024 + DefaultPieceSize
if mpSize > DefaultPieceSizeLimit {
return DefaultPieceSizeLimit
}
return uint32(mpSize)
}
// ComputePieceNum returns piece count with given length and pieceSize
func ComputePieceNum(length int64, pieceSize uint32) int32 {
return int32(math.Ceil(float64(length) / float64(pieceSize)))
}