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1   /*
2    * Copyright (C) 2012, 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.lib;
45  
46  import java.util.Iterator;
47  
48  import org.eclipse.jgit.internal.storage.file.PackBitmapIndex;
49  
50  /**
51   * A compressed bitmap representation of the entire object graph.
52   *
53   * @since 3.0
54   */
55  public interface BitmapIndex {
56  	/**
57  	 * Get the bitmap for the id. The returned bitmap is immutable and the
58  	 * bitwise operations return the result of the operation in a new Bitmap.
59  	 *
60  	 * @param objectId
61  	 *            the object ID
62  	 * @return the Bitmap for the objectId or null, if one does not exist.
63  	 */
64  	Bitmap getBitmap(AnyObjectId objectId);
65  
66  	/**
67  	 * Create a new {@code BitmapBuilder} based on the values in the index.
68  	 *
69  	 * @return a new {@code BitmapBuilder} based on the values in the index.
70  	 */
71  	BitmapBuilder newBitmapBuilder();
72  
73  	/**
74  	 * A bitmap representation of ObjectIds that can be iterated to return the
75  	 * underlying {@code ObjectId}s or operated on with other {@code Bitmap}s.
76  	 */
77  	public interface Bitmap extends Iterable<BitmapObject> {
78  		/**
79  		 * Bitwise-OR the current bitmap with the value from the other
80  		 * bitmap.
81  		 *
82  		 * @param other
83  		 *            the other bitmap
84  		 * @return a bitmap that is the bitwise-OR.
85  		 */
86  		Bitmap or(Bitmap other);
87  
88  		/**
89  		 * Bitwise-AND-NOT the current bitmap with the value from the other
90  		 * bitmap.
91  		 *
92  		 * @param other
93  		 *            the other bitmap
94  		 * @return a bitmap that is the bitwise-AND-NOT.
95  		 */
96  		Bitmap andNot(Bitmap other);
97  
98  		/**
99  		 * Bitwise-XOR the current bitmap with the value from the other
100 		 * bitmap.
101 		 *
102 		 * @param other
103 		 *            the other bitmap
104 		 * @return a bitmap that is the bitwise-XOR.
105 		 */
106 		Bitmap xor(Bitmap other);
107 
108 		/**
109 		 * Returns an iterator over a set of elements of type BitmapObject. The
110 		 * BitmapObject instance is reused across calls to
111 		 * {@link Iterator#next()} for performance reasons.
112 		 *
113 		 * @return an Iterator.
114 		 */
115 		@Override
116 		Iterator<BitmapObject> iterator();
117 	}
118 
119 	/**
120 	 * A builder for a bitmap. The bitwise operations update the builder and
121 	 * return a reference to the current builder.
122 	 */
123 	public interface BitmapBuilder extends Bitmap {
124 
125 		/**
126 		 * Whether the bitmap has the id set.
127 		 *
128 		 * @param objectId
129 		 *            the object ID
130 		 * @return whether the bitmap currently contains the object ID
131 		 */
132 		boolean contains(AnyObjectId objectId);
133 
134 		/**
135 		 * Adds the id to the bitmap.
136 		 *
137 		 * @param objectId
138 		 *            the object ID
139 		 * @param type
140 		 *            the Git object type. See {@link Constants}.
141 		 * @return the current builder.
142 		 * @since 4.2
143 		 */
144 		BitmapBuilder addObject(AnyObjectId objectId, int type);
145 
146 		/**
147 		 * Remove the id from the bitmap.
148 		 *
149 		 * @param objectId
150 		 *            the object ID
151 		 */
152 		void remove(AnyObjectId objectId);
153 
154 		/**
155 		 * Bitwise-OR the current bitmap with the value from the other bitmap.
156 		 *
157 		 * @param other
158 		 *            the other bitmap
159 		 * @return the current builder.
160 		 */
161 		@Override
162 		BitmapBuilder or(Bitmap other);
163 
164 		/**
165 		 * Bitwise-AND-NOT the current bitmap with the value from the other
166 		 * bitmap.
167 		 *
168 		 * @param other
169 		 *            the other bitmap
170 		 * @return the current builder.
171 		 */
172 		@Override
173 		BitmapBuilder andNot(Bitmap other);
174 
175 		/**
176 		 * Bitwise-XOR the current bitmap with the value from the other bitmap.
177 		 *
178 		 * @param other
179 		 *            the other bitmap
180 		 * @return the current builder.
181 		 */
182 		@Override
183 		BitmapBuilder xor(Bitmap other);
184 
185 		/** @return the fully built immutable bitmap */
186 		Bitmap build();
187 
188 		/**
189 		 * Determines if the entire bitmap index is contained in the bitmap. If
190 		 * it is, the matching bits are removed from the bitmap and true is
191 		 * returned. If the bitmap index is null, false is returned.
192 		 *
193 		 * @param bitmapIndex
194 		 *            the bitmap index to check if it is completely contained
195 		 *            inside of the current bitmap.
196 		 * @return {@code true} if the bitmap index was a complete match.
197 		 */
198 		boolean removeAllOrNone(PackBitmapIndex bitmapIndex);
199 
200 		/** @return the number of elements in the bitmap. */
201 		int cardinality();
202 
203 		/**
204 		 * Get the BitmapIndex for this BitmapBuilder.
205 		 *
206 		 * @return the BitmapIndex for this BitmapBuilder
207 		 *
208 		 * @since 4.2
209 		 */
210 		BitmapIndex getBitmapIndex();
211 	}
212 }