1 /*
2 * Copyright (C) 2011, Google Inc.
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43
44 package org.eclipse.jgit.blame;
45
46 /**
47 * Region of the result that still needs to be computed.
48 * <p>
49 * Regions are held in a singly-linked-list by {@link Candidate} using the
50 * {@link Candidate#regionList} field. The list is kept in sorted order by
51 * {@link #resultStart}.
52 */
53 class Region {
54 /** Next entry in the region linked list. */
55 Region next;
56
57 /** First position of this region in the result file blame is computing. */
58 int resultStart;
59
60 /** First position in the {@link Candidate} that owns this Region. */
61 int sourceStart;
62
63 /** Length of the region, always >= 1. */
64 int length;
65
66 Region(int rs, int ss, int len) {
67 resultStart = rs;
68 sourceStart = ss;
69 length = len;
70 }
71
72 /**
73 * Copy the entire result region, but at a new source position.
74 *
75 * @param newSource
76 * the new source position.
77 * @return the same result region, but offset for a new source.
78 */
79 Region copy(int newSource) {
80 return new Region(resultStart, newSource, length);
81 }
82
83 /**
84 * Split the region, assigning a new source position to the first half.
85 *
86 * @param newSource
87 * the new source position.
88 * @param newLen
89 * length of the new region.
90 * @return the first half of the region, at the new source.
91 */
92 Region splitFirst(int newSource, int newLen) {
93 return new Region(resultStart, newSource, newLen);
94 }
95
96 /**
97 * Edit this region to remove the first {@code d} elements.
98 *
99 * @param d
100 * number of elements to remove from the start of this region.
101 */
102 void slideAndShrink(int d) {
103 resultStart += d;
104 sourceStart += d;
105 length -= d;
106 }
107
108 Region deepCopy() {
109 Region head = new Region(resultStart, sourceStart, length);
110 Region tail = head;
111 for (Region n = next; n != null; n = n.next) {
112 Region q = new Region(n.resultStart, n.sourceStart, n.length);
113 tail.next = q;
114 tail = q;
115 }
116 return head;
117 }
118
119 /** {@inheritDoc} */
120 @Override
121 public String toString() {
122 StringBuilder buf = new StringBuilder();
123 Region r = this;
124 do {
125 if (r != this)
126 buf.append(',');
127 buf.append(r.resultStart);
128 buf.append('-');
129 buf.append(r.resultStart + r.length);
130 r = r.next;
131 } while (r != null);
132 return buf.toString();
133 }
134 }