1. docker
  2. Commit 2d2016b81b1f313cda2c8f145844b162352ba234
Browse code

pkg/pool: add pools for bufio readers & writers

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)

unclejack authored on 2014/08/13 01:27:19
Showing 2 changed files
pkg/pools/pools.go
History View file @ 2d2016b
1 1 
new file mode 100644
... ... 
@@ -0,0 +1,111 @@
0 
+// +build go1.3
1 
+
2 
+// Package pools provides a collection of pools which provide various
3 
+// data types with buffers. These can be used to lower the number of
4 
+// memory allocations and reuse buffers.
5 
+//
6 
+// New pools should be added to this package to allow them to be
7 
+// shared across packages.
8 
+//
9 
+// Utility functions which operate on pools should be added to this
10 
+// package to allow them to be reused.
11 
+package pools
12 
+
13 
+import (
14 
+	"bufio"
15 
+	"io"
16 
+	"sync"
17 
+
18 
+	"github.com/docker/docker/pkg/ioutils"
19 
+)
20 
+
21 
+var (
22 
+	// Pool which returns bufio.Reader with a 32K buffer
23 
+	BufioReader32KPool *BufioReaderPool
24 
+	// Pool which returns bufio.Writer with a 32K buffer
25 
+	BufioWriter32KPool *BufioWriterPool
26 
+)
27 
+
28 
+const buffer32K = 32 * 1024
29 
+
30 
+type BufioReaderPool struct {
31 
+	pool sync.Pool
32 
+}
33 
+
34 
+func init() {
35 
+	BufioReader32KPool = newBufioReaderPoolWithSize(buffer32K)
36 
+	BufioWriter32KPool = newBufioWriterPoolWithSize(buffer32K)
37 
+}
38 
+
39 
+// newBufioReaderPoolWithSize is unexported because new pools should be
40 
+// added here to be shared where required.
41 
+func newBufioReaderPoolWithSize(size int) *BufioReaderPool {
42 
+	pool := sync.Pool{
43 
+		New: func() interface{} { return bufio.NewReaderSize(nil, size) },
44 
+	}
45 
+	return &BufioReaderPool{pool: pool}
46 
+}
47 
+
48 
+// Get returns a bufio.Reader which reads from r. The buffer size is that of the pool.
49 
+func (bufPool *BufioReaderPool) Get(r io.Reader) *bufio.Reader {
50 
+	buf := bufPool.pool.Get().(*bufio.Reader)
51 
+	buf.Reset(r)
52 
+	return buf
53 
+}
54 
+
55 
+// Put puts the bufio.Reader back into the pool.
56 
+func (bufPool *BufioReaderPool) Put(b *bufio.Reader) {
57 
+	b.Reset(nil)
58 
+	bufPool.pool.Put(b)
59 
+}
60 
+
61 
+// NewReadCloserWrapper returns a wrapper which puts the bufio.Reader back
62 
+// into the pool and closes the reader if it's an io.ReadCloser.
63 
+func (bufPool *BufioReaderPool) NewReadCloserWrapper(buf *bufio.Reader, r io.Reader) io.ReadCloser {
64 
+	return ioutils.NewReadCloserWrapper(r, func() error {
65 
+		if readCloser, ok := r.(io.ReadCloser); ok {
66 
+			readCloser.Close()
67 
+		}
68 
+		bufPool.Put(buf)
69 
+		return nil
70 
+	})
71 
+}
72 
+
73 
+type BufioWriterPool struct {
74 
+	pool sync.Pool
75 
+}
76 
+
77 
+// newBufioWriterPoolWithSize is unexported because new pools should be
78 
+// added here to be shared where required.
79 
+func newBufioWriterPoolWithSize(size int) *BufioWriterPool {
80 
+	pool := sync.Pool{
81 
+		New: func() interface{} { return bufio.NewWriterSize(nil, size) },
82 
+	}
83 
+	return &BufioWriterPool{pool: pool}
84 
+}
85 
+
86 
+// Get returns a bufio.Writer which writes to w. The buffer size is that of the pool.
87 
+func (bufPool *BufioWriterPool) Get(w io.Writer) *bufio.Writer {
88 
+	buf := bufPool.pool.Get().(*bufio.Writer)
89 
+	buf.Reset(w)
90 
+	return buf
91 
+}
92 
+
93 
+// Put puts the bufio.Writer back into the pool.
94 
+func (bufPool *BufioWriterPool) Put(b *bufio.Writer) {
95 
+	b.Reset(nil)
96 
+	bufPool.pool.Put(b)
97 
+}
98 
+
99 
+// NewWriteCloserWrapper returns a wrapper which puts the bufio.Writer back
100 
+// into the pool and closes the writer if it's an io.Writecloser.
101 
+func (bufPool *BufioWriterPool) NewWriteCloserWrapper(buf *bufio.Writer, w io.Writer) io.WriteCloser {
102 
+	return ioutils.NewWriteCloserWrapper(w, func() error {
103 
+		buf.Flush()
104 
+		if writeCloser, ok := w.(io.WriteCloser); ok {
105 
+			writeCloser.Close()
106 
+		}
107 
+		bufPool.Put(buf)
108 
+		return nil
109 
+	})
110 
+}
pkg/pools/pools_nopool.go
History View file @ 2d2016b
0 111 
new file mode 100644
... ... 
@@ -0,0 +1,73 @@
0 
+// +build !go1.3
1 
+
2 
+package pools
3 
+
4 
+import (
5 
+	"bufio"
6 
+	"io"
7 
+
8 
+	"github.com/docker/docker/pkg/ioutils"
9 
+)
10 
+
11 
+var (
12 
+	BufioReader32KPool *BufioReaderPool
13 
+	BufioWriter32KPool *BufioWriterPool
14 
+)
15 
+
16 
+const buffer32K = 32 * 1024
17 
+
18 
+type BufioReaderPool struct {
19 
+	size int
20 
+}
21 
+
22 
+func init() {
23 
+	BufioReader32KPool = newBufioReaderPoolWithSize(buffer32K)
24 
+	BufioWriter32KPool = newBufioWriterPoolWithSize(buffer32K)
25 
+}
26 
+
27 
+func newBufioReaderPoolWithSize(size int) *BufioReaderPool {
28 
+	return &BufioReaderPool{size: size}
29 
+}
30 
+
31 
+func (bufPool *BufioReaderPool) Get(r io.Reader) *bufio.Reader {
32 
+	return bufio.NewReaderSize(r, bufPool.size)
33 
+}
34 
+
35 
+func (bufPool *BufioReaderPool) Put(b *bufio.Reader) {
36 
+	b.Reset(nil)
37 
+}
38 
+
39 
+func (bufPool *BufioReaderPool) NewReadCloserWrapper(buf *bufio.Reader, r io.Reader) io.ReadCloser {
40 
+	return ioutils.NewReadCloserWrapper(r, func() error {
41 
+		if readCloser, ok := r.(io.ReadCloser); ok {
42 
+			return readCloser.Close()
43 
+		}
44 
+		return nil
45 
+	})
46 
+}
47 
+
48 
+type BufioWriterPool struct {
49 
+	size int
50 
+}
51 
+
52 
+func newBufioWriterPoolWithSize(size int) *BufioWriterPool {
53 
+	return &BufioWriterPool{size: size}
54 
+}
55 
+
56 
+func (bufPool *BufioWriterPool) Get(w io.Writer) *bufio.Writer {
57 
+	return bufio.NewWriterSize(w, bufPool.size)
58 
+}
59 
+
60 
+func (bufPool *BufioWriterPool) Put(b *bufio.Writer) {
61 
+	b.Reset(nil)
62 
+}
63 
+
64 
+func (bufPool *BufioWriterPool) NewWriteCloserWrapper(buf *bufio.Writer, w io.Writer) io.WriteCloser {
65 
+	return ioutils.NewWriteCloserWrapper(w, func() error {
66 
+		buf.Flush()
67 
+		if writeCloser, ok := w.(io.WriteCloser); ok {
68 
+			return writeCloser.Close()
69 
+		}
70 
+		return nil
71 
+	})
72 
+}