-
Notifications
You must be signed in to change notification settings - Fork 113
/
BufferRecycler.java
177 lines (153 loc) · 4.98 KB
/
BufferRecycler.java
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
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
* Copyright (C) 2011 the original author or authors.
* See the notice.md file distributed with this work for additional
* information regarding copyright ownership.
*
* 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 org.iq80.snappy;
import java.lang.ref.SoftReference;
/**
* Simple helper class to encapsulate details of basic buffer
* recycling scheme, which helps a lot (as per profiling) for
* smaller encoding cases.
*
* @author tatu
*/
class BufferRecycler
{
private final static int MIN_ENCODING_BUFFER = 4000;
private final static int MIN_OUTPUT_BUFFER = 8000;
/**
* This <code>ThreadLocal</code> contains a {@link java.lang.ref.SoftReference}
* to a {@link BufferRecycler} used to provide a low-cost
* buffer recycling for buffers we need for encoding, decoding.
*/
final protected static ThreadLocal<SoftReference<BufferRecycler>> recyclerRef
= new ThreadLocal<SoftReference<BufferRecycler>>();
private byte[] inputBuffer;
private byte[] outputBuffer;
private byte[] decodingBuffer;
private byte[] encodingBuffer;
private short[] encodingHash;
/**
* Accessor to get thread-local recycler instance
*/
public static BufferRecycler instance()
{
SoftReference<BufferRecycler> ref = recyclerRef.get();
BufferRecycler bufferRecycler;
if (ref == null) {
bufferRecycler = null;
}
else {
bufferRecycler = ref.get();
}
if (bufferRecycler == null) {
bufferRecycler = new BufferRecycler();
recyclerRef.set(new SoftReference<BufferRecycler>(bufferRecycler));
}
return bufferRecycler;
}
///////////////////////////////////////////////////////////////////////
// Buffers for encoding (output)
///////////////////////////////////////////////////////////////////////
public byte[] allocEncodingBuffer(int minSize)
{
byte[] buf = encodingBuffer;
if (buf == null || buf.length < minSize) {
buf = new byte[Math.max(minSize, MIN_ENCODING_BUFFER)];
}
else {
encodingBuffer = null;
}
return buf;
}
public void releaseEncodeBuffer(byte[] buffer)
{
if (encodingBuffer == null || buffer.length > encodingBuffer.length) {
encodingBuffer = buffer;
}
}
public byte[] allocOutputBuffer(int minSize)
{
byte[] buf = outputBuffer;
if (buf == null || buf.length < minSize) {
buf = new byte[Math.max(minSize, MIN_OUTPUT_BUFFER)];
}
else {
outputBuffer = null;
}
return buf;
}
public void releaseOutputBuffer(byte[] buffer)
{
if (outputBuffer == null || (buffer != null && buffer.length > outputBuffer.length)) {
outputBuffer = buffer;
}
}
public short[] allocEncodingHash(int suggestedSize)
{
short[] buf = encodingHash;
if (buf == null || buf.length < suggestedSize) {
buf = new short[suggestedSize];
}
else {
encodingHash = null;
}
return buf;
}
public void releaseEncodingHash(short[] buffer)
{
if (encodingHash == null || (buffer != null && buffer.length > encodingHash.length)) {
encodingHash = buffer;
}
}
///////////////////////////////////////////////////////////////////////
// Buffers for decoding (input)
///////////////////////////////////////////////////////////////////////
public byte[] allocInputBuffer(int minSize)
{
byte[] buf = inputBuffer;
if (buf == null || buf.length < minSize) {
buf = new byte[Math.max(minSize, MIN_OUTPUT_BUFFER)];
}
else {
inputBuffer = null;
}
return buf;
}
public void releaseInputBuffer(byte[] buffer)
{
if (inputBuffer == null || (buffer != null && buffer.length > inputBuffer.length)) {
inputBuffer = buffer;
}
}
public byte[] allocDecodeBuffer(int size)
{
byte[] buf = decodingBuffer;
if (buf == null || buf.length < size) {
buf = new byte[size];
}
else {
decodingBuffer = null;
}
return buf;
}
public void releaseDecodeBuffer(byte[] buffer)
{
if (decodingBuffer == null || (buffer != null && buffer.length > decodingBuffer.length)) {
decodingBuffer = buffer;
}
}
}