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
|
/*
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.jgit.revwalk;
import java.io.IOException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
abstract class BlockRevQueue extends AbstractRevQueue {
protected BlockFreeList free;
/**
* Create an empty revision queue.
*/
protected BlockRevQueue() {
free = new BlockFreeList();
}
BlockRevQueue(Generator s) throws MissingObjectException,
IncorrectObjectTypeException, IOException {
free = new BlockFreeList();
outputType = s.outputType();
s.shareFreeList(this);
for (;;) {
final RevCommit c = s.next();
if (c == null)
break;
add(c);
}
}
/**
* {@inheritDoc}
* <p>
* Reconfigure this queue to share the same free list as another.
* <p>
* Multiple revision queues can be connected to the same free list, making
* it less expensive for applications to shuttle commits between them. This
* method arranges for the receiver to take from / return to the same free
* list as the supplied queue.
* <p>
* Free lists are not thread-safe. Applications must ensure that all queues
* sharing the same free list are doing so from only a single thread.
*/
@Override
public void shareFreeList(BlockRevQueue q) {
free = q.free;
}
static final class BlockFreeList {
private Block next;
Block newBlock() {
Block b = next;
if (b == null)
return new Block();
next = b.next;
b.clear();
return b;
}
void freeBlock(Block b) {
b.next = next;
next = b;
}
void clear() {
next = null;
}
}
static final class Block {
static final int BLOCK_SIZE = 256;
/** Next block in our chain of blocks; null if we are the last. */
Block next;
/** Our table of queued commits. */
final RevCommit[] commits = new RevCommit[BLOCK_SIZE];
/** Next valid entry in {@link #commits}. */
int headIndex;
/** Next free entry in {@link #commits} for addition at. */
int tailIndex;
boolean isFull() {
return tailIndex == BLOCK_SIZE;
}
boolean isEmpty() {
return headIndex == tailIndex;
}
boolean canUnpop() {
return headIndex > 0;
}
void add(RevCommit c) {
commits[tailIndex++] = c;
}
void unpop(RevCommit c) {
commits[--headIndex] = c;
}
RevCommit pop() {
return commits[headIndex++];
}
RevCommit peek() {
return commits[headIndex];
}
void clear() {
next = null;
headIndex = 0;
tailIndex = 0;
}
void resetToMiddle() {
headIndex = tailIndex = BLOCK_SIZE / 2;
}
void resetToEnd() {
headIndex = tailIndex = BLOCK_SIZE;
}
}
}
|
