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
|
package org.apache.lucene.store.bytebuffer;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
import org.apache.lucene.store.IndexOutput;
import java.io.IOException;
import java.nio.ByteBuffer;
/**
*/
public class ByteBufferIndexOutput extends IndexOutput {
private final static ByteBuffer EMPTY_BUFFER = ByteBuffer.allocate(0).asReadOnlyBuffer();
private final ByteBufferDirectory dir;
private final String name;
private final ByteBufferAllocator allocator;
private final ByteBufferAllocator.Type allocatorType;
private final int BUFFER_SIZE;
private final ByteBufferFileOutput file;
private ByteBuffer currentBuffer;
private int currentBufferIndex;
private long bufferStart;
public ByteBufferIndexOutput(ByteBufferDirectory dir, String name, ByteBufferAllocator allocator, ByteBufferAllocator.Type allocatorType, ByteBufferFileOutput file) throws IOException {
this.dir = dir;
this.name = name;
this.allocator = allocator;
this.allocatorType = allocatorType;
this.BUFFER_SIZE = file.bufferSize;
this.file = file;
currentBufferIndex = -1;
currentBuffer = EMPTY_BUFFER;
}
@Override
public void close() throws IOException {
flush();
dir.closeOutput(name, file);
}
@Override
public void seek(long pos) throws IOException {
// set the file length in case we seek back
// and flush() has not been called yet
setFileLength();
if (pos < bufferStart || pos >= bufferStart + BUFFER_SIZE) {
currentBufferIndex = (int) (pos / BUFFER_SIZE);
switchCurrentBuffer();
}
currentBuffer.position((int) (pos % BUFFER_SIZE));
}
@Override
public long length() {
return file.getLength();
}
@Override
public void writeByte(byte b) throws IOException {
if (!currentBuffer.hasRemaining()) {
currentBufferIndex++;
switchCurrentBuffer();
}
currentBuffer.put(b);
}
@Override
public void writeBytes(byte[] b, int offset, int len) throws IOException {
while (len > 0) {
if (!currentBuffer.hasRemaining()) {
currentBufferIndex++;
switchCurrentBuffer();
}
int remainInBuffer = currentBuffer.remaining();
int bytesToCopy = len < remainInBuffer ? len : remainInBuffer;
currentBuffer.put(b, offset, bytesToCopy);
offset += bytesToCopy;
len -= bytesToCopy;
}
}
private void switchCurrentBuffer() throws IOException {
if (currentBufferIndex == file.numBuffers()) {
currentBuffer = allocator.allocate(allocatorType);
file.addBuffer(currentBuffer);
} else {
currentBuffer = file.getBuffer(currentBufferIndex);
}
currentBuffer.position(0);
bufferStart = (long) BUFFER_SIZE * (long) currentBufferIndex;
}
private void setFileLength() {
long pointer = bufferStart + currentBuffer.position();
if (pointer > file.getLength()) {
file.setLength(pointer);
}
}
@Override
public void flush() throws IOException {
file.setLastModified(System.currentTimeMillis());
setFileLength();
}
@Override
public long getFilePointer() {
return currentBufferIndex < 0 ? 0 : bufferStart + currentBuffer.position();
}
}
|
