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1   /*
2    * Copyright (C) 2017, 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
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8    * available at http://www.eclipse.org/org/documents/edl-v10.php
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13   * without modification, are permitted provided that the following
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43  
44  package org.eclipse.jgit.internal.storage.reftable;
45  
46  import static org.eclipse.jgit.internal.storage.reftable.ReftableConstants.MAX_BLOCK_SIZE;
47  
48  import org.eclipse.jgit.lib.Config;
49  import org.eclipse.jgit.lib.Repository;
50  
51  /** Configuration used by a reftable writer when constructing the stream. */
52  public class ReftableConfig {
53  	private int refBlockSize = 4 << 10;
54  	private int logBlockSize;
55  	private int restartInterval;
56  	private int maxIndexLevels;
57  	private boolean alignBlocks = true;
58  	private boolean indexObjects = true;
59  
60  	/** Create a default configuration. */
61  	public ReftableConfig() {
62  	}
63  
64  	/**
65  	 * Create a configuration honoring the repository's settings.
66  	 *
67  	 * @param db
68  	 *            the repository to read settings from. The repository is not
69  	 *            retained by the new configuration, instead its settings are
70  	 *            copied during the constructor.
71  	 */
72  	public ReftableConfig(Repository db) {
73  		fromConfig(db.getConfig());
74  	}
75  
76  	/**
77  	 * Create a configuration honoring settings in a {@link Config}.
78  	 *
79  	 * @param cfg
80  	 *            the source to read settings from. The source is not retained
81  	 *            by the new configuration, instead its settings are copied
82  	 *            during the constructor.
83  	 */
84  	public ReftableConfig(Config cfg) {
85  		fromConfig(cfg);
86  	}
87  
88  	/**
89  	 * Copy an existing configuration to a new instance.
90  	 *
91  	 * @param cfg
92  	 *            the source configuration to copy from.
93  	 */
94  	public ReftableConfig(ReftableConfig cfg) {
95  		this.refBlockSize = cfg.refBlockSize;
96  		this.logBlockSize = cfg.logBlockSize;
97  		this.restartInterval = cfg.restartInterval;
98  		this.maxIndexLevels = cfg.maxIndexLevels;
99  		this.alignBlocks = cfg.alignBlocks;
100 		this.indexObjects = cfg.indexObjects;
101 	}
102 
103 	/** @return desired output block size for references, in bytes */
104 	public int getRefBlockSize() {
105 		return refBlockSize;
106 	}
107 
108 	/**
109 	 * @param szBytes
110 	 *            desired output block size for references, in bytes.
111 	 */
112 	public void setRefBlockSize(int szBytes) {
113 		if (szBytes > MAX_BLOCK_SIZE) {
114 			throw new IllegalArgumentException();
115 		}
116 		refBlockSize = Math.max(0, szBytes);
117 	}
118 
119 	/**
120 	 * @return desired output block size for log entries, in bytes. If 0 the
121 	 *         writer will default to {@code 2 * getRefBlockSize()}.
122 	 */
123 	public int getLogBlockSize() {
124 		return logBlockSize;
125 	}
126 
127 	/**
128 	 * @param szBytes
129 	 *            desired output block size for log entries, in bytes. If 0 will
130 	 *            default to {@code 2 * getRefBlockSize()}.
131 	 */
132 	public void setLogBlockSize(int szBytes) {
133 		if (szBytes > MAX_BLOCK_SIZE) {
134 			throw new IllegalArgumentException();
135 		}
136 		logBlockSize = Math.max(0, szBytes);
137 	}
138 
139 	/** @return number of references between binary search markers. */
140 	public int getRestartInterval() {
141 		return restartInterval;
142 	}
143 
144 	/**
145 	 * @param interval
146 	 *            number of references between binary search markers. If
147 	 *            {@code interval} is 0 (default), the writer will select a
148 	 *            default value based on the block size.
149 	 */
150 	public void setRestartInterval(int interval) {
151 		restartInterval = Math.max(0, interval);
152 	}
153 
154 	/** @return maximum depth of the index; 0 for unlimited. */
155 	public int getMaxIndexLevels() {
156 		return maxIndexLevels;
157 	}
158 
159 	/**
160 	 * @param levels
161 	 *            maximum number of levels to use in indexes. Lower levels of
162 	 *            the index respect {@link #getRefBlockSize()}, and the highest
163 	 *            level may exceed that if the number of levels is limited.
164 	 */
165 	public void setMaxIndexLevels(int levels) {
166 		maxIndexLevels = Math.max(0, levels);
167 	}
168 
169 	/** @return {@code true} if the writer should align blocks. */
170 	public boolean isAlignBlocks() {
171 		return alignBlocks;
172 	}
173 
174 	/**
175 	 * @param align
176 	 *            if {@code true} blocks are written aligned to multiples of
177 	 *            {@link #getRefBlockSize()}. May increase file size due to NUL
178 	 *            padding bytes added between blocks. Default is {@code true}.
179 	 */
180 	public void setAlignBlocks(boolean align) {
181 		alignBlocks = align;
182 	}
183 
184 	/** @return {@code true} if the writer should index object to ref. */
185 	public boolean isIndexObjects() {
186 		return indexObjects;
187 	}
188 
189 	/**
190 	 * @param index
191 	 *            if {@code true} the reftable may include additional storage to
192 	 *            efficiently map from {@code ObjectId} to reference names. By
193 	 *            default, {@code true}.
194 	 */
195 	public void setIndexObjects(boolean index) {
196 		indexObjects = index;
197 	}
198 
199 	/**
200 	 * Update properties by setting fields from the configuration.
201 	 *
202 	 * If a property's corresponding variable is not defined in the supplied
203 	 * configuration, then it is left unmodified.
204 	 *
205 	 * @param rc
206 	 *            configuration to read properties from.
207 	 */
208 	public void fromConfig(Config rc) {
209 		refBlockSize = rc.getInt("reftable", "blockSize", refBlockSize); //$NON-NLS-1$ //$NON-NLS-2$
210 		logBlockSize = rc.getInt("reftable", "logBlockSize", logBlockSize); //$NON-NLS-1$ //$NON-NLS-2$
211 		restartInterval = rc.getInt("reftable", "restartInterval", restartInterval); //$NON-NLS-1$ //$NON-NLS-2$
212 		maxIndexLevels = rc.getInt("reftable", "indexLevels", maxIndexLevels); //$NON-NLS-1$ //$NON-NLS-2$
213 		alignBlocks = rc.getBoolean("reftable", "alignBlocks", alignBlocks); //$NON-NLS-1$ //$NON-NLS-2$
214 		indexObjects = rc.getBoolean("reftable", "indexObjects", indexObjects); //$NON-NLS-1$ //$NON-NLS-2$
215 	}
216 }