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
|
package manager
import (
"bufio"
"io"
"sync"
"github.com/aws/aws-sdk-go-v2/internal/sdkio"
)
// WriterReadFrom defines an interface implementing io.Writer and io.ReaderFrom
type WriterReadFrom interface {
io.Writer
io.ReaderFrom
}
// WriterReadFromProvider provides an implementation of io.ReadFrom for the given io.Writer
type WriterReadFromProvider interface {
GetReadFrom(writer io.Writer) (w WriterReadFrom, cleanup func())
}
type bufferedWriter interface {
WriterReadFrom
Flush() error
Reset(io.Writer)
}
type bufferedReadFrom struct {
bufferedWriter
}
func (b *bufferedReadFrom) ReadFrom(r io.Reader) (int64, error) {
n, err := b.bufferedWriter.ReadFrom(r)
if flushErr := b.Flush(); flushErr != nil && err == nil {
err = flushErr
}
return n, err
}
// PooledBufferedReadFromProvider is a WriterReadFromProvider that uses a sync.Pool
// to manage allocation and reuse of *bufio.Writer structures.
type PooledBufferedReadFromProvider struct {
pool sync.Pool
}
// NewPooledBufferedWriterReadFromProvider returns a new PooledBufferedReadFromProvider
// Size is used to control the size of the underlying *bufio.Writer created for
// calls to GetReadFrom.
func NewPooledBufferedWriterReadFromProvider(size int) *PooledBufferedReadFromProvider {
if size < int(32*sdkio.KibiByte) {
size = int(64 * sdkio.KibiByte)
}
return &PooledBufferedReadFromProvider{
pool: sync.Pool{
New: func() interface{} {
return &bufferedReadFrom{bufferedWriter: bufio.NewWriterSize(nil, size)}
},
},
}
}
// GetReadFrom takes an io.Writer and wraps it with a type which satisfies the WriterReadFrom
// interface/ Additionally a cleanup function is provided which must be called after usage of the WriterReadFrom
// has been completed in order to allow the reuse of the *bufio.Writer
func (p *PooledBufferedReadFromProvider) GetReadFrom(writer io.Writer) (r WriterReadFrom, cleanup func()) {
buffer := p.pool.Get().(*bufferedReadFrom)
buffer.Reset(writer)
r = buffer
cleanup = func() {
buffer.Reset(nil) // Reset to nil writer to release reference
p.pool.Put(buffer)
}
return r, cleanup
}
type suppressWriterAt struct {
suppressed io.Reader
}
func (s *suppressWriterAt) Read(p []byte) (n int, err error) {
return s.suppressed.Read(p)
}
|
