diff options
Diffstat (limited to 'org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdOwnerMap.java')
| -rw-r--r-- | org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdOwnerMap.java | 130 |
1 files changed, 58 insertions, 72 deletions
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdOwnerMap.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdOwnerMap.java index c9b483f7f0..a74fddff42 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdOwnerMap.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectIdOwnerMap.java @@ -1,44 +1,11 @@ /* - * Copyright (C) 2011, Google Inc. - * and other copyright owners as documented in the project's IP log. + * Copyright (C) 2011, Google Inc. and others * - * 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 + * This program and the accompanying materials are made available under the + * terms of the Eclipse Distribution License v. 1.0 which is available at + * https://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. + * SPDX-License-Identifier: BSD-3-Clause */ package org.eclipse.jgit.lib; @@ -48,10 +15,12 @@ import java.util.Iterator; import java.util.NoSuchElementException; /** - * Fast, efficient map for {@link ObjectId} subclasses in only one map. + * Fast, efficient map for {@link org.eclipse.jgit.lib.ObjectId} subclasses in + * only one map. * <p> * To use this map type, applications must have their entry value type extend - * from {@link ObjectIdOwnerMap.Entry}, which itself extends from ObjectId. + * from {@link org.eclipse.jgit.lib.ObjectIdOwnerMap.Entry}, which itself + * extends from ObjectId. * <p> * Object instances may only be stored in <b>ONE</b> ObjectIdOwnerMap. This * restriction exists because the map stores internal map state within each @@ -59,16 +28,17 @@ import java.util.NoSuchElementException; * could corrupt one or both map's internal state. * <p> * If an object instance must be in more than one map, applications may use - * ObjectIdOwnerMap for one of the maps, and {@link ObjectIdSubclassMap} for the - * other map(s). It is encouraged to use ObjectIdOwnerMap for the map that is - * accessed most often, as this implementation runs faster than the more general - * ObjectIdSubclassMap implementation. + * ObjectIdOwnerMap for one of the maps, and + * {@link org.eclipse.jgit.lib.ObjectIdSubclassMap} for the other map(s). It is + * encouraged to use ObjectIdOwnerMap for the map that is accessed most often, + * as this implementation runs faster than the more general ObjectIdSubclassMap + * implementation. * * @param <V> * type of subclass of ObjectId that will be stored in the map. */ -public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements - Iterable<V> { +public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> + implements Iterable<V>, ObjectIdSet { /** Size of the initial directory, will grow as necessary. */ private static final int INITIAL_DIRECTORY = 1024; @@ -83,21 +53,23 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements * The low {@link #bits} of the SHA-1 are used to select the segment from * this directory. Each segment is constant sized at 2^SEGMENT_BITS. */ - private V[][] directory; + V[][] directory; /** Total number of objects in this map. */ - private int size; + int size; /** The map doubles in capacity when {@link #size} reaches this target. */ private int grow; /** Number of low bits used to form the index into {@link #directory}. */ - private int bits; + int bits; /** Low bit mask to index into {@link #directory}, {@code 2^bits-1}. */ private int mask; - /** Create an empty map. */ + /** + * Create an empty map. + */ @SuppressWarnings("unchecked") public ObjectIdOwnerMap() { bits = 0; @@ -108,7 +80,9 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements directory[0] = newSegment(); } - /** Remove all entries from this map. */ + /** + * Remove all entries from this map. + */ public void clear() { size = 0; @@ -127,7 +101,10 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements * @return the instance mapped to toFind, or null if no mapping exists. */ @SuppressWarnings("unchecked") - public V get(final AnyObjectId toFind) { + public V get(AnyObjectId toFind) { + if (toFind == null) { + return null; + } int h = toFind.w1; V obj = directory[h & mask][h >>> SEGMENT_SHIFT]; for (; obj != null; obj = (V) obj.next) @@ -137,13 +114,12 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements } /** + * {@inheritDoc} + * <p> * Returns true if this map contains the specified object. - * - * @param toFind - * object to find. - * @return true if the mapping exists for this object; false otherwise. */ - public boolean contains(final AnyObjectId toFind) { + @Override + public boolean contains(AnyObjectId toFind) { return get(toFind) != null; } @@ -152,14 +128,15 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements * <p> * An existing mapping for <b>must not</b> be in this map. Callers must * first call {@link #get(AnyObjectId)} to verify there is no current - * mapping prior to adding a new mapping, or use {@link #addIfAbsent(Entry)}. + * mapping prior to adding a new mapping, or use + * {@link #addIfAbsent(Entry)}. * + * @param <Q> + * type of values * @param newValue * the object to store. - * @param <Q> - * type of instance to store. */ - public <Q extends V> void add(final Q newValue) { + public <Q extends V> void add(Q newValue) { if (++size == grow) grow(); @@ -183,16 +160,16 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements * boolean wasNew = map.addIfAbsent(obj) == obj; * </pre> * + * @param <Q> + * type of values * @param newValue * the object to store. * @return {@code newValue} if stored, or the prior value already stored and * that would have been returned had the caller used * {@code get(newValue)} first. - * @param <Q> - * type of instance to store. */ @SuppressWarnings("unchecked") - public <Q extends V> V addIfAbsent(final Q newValue) { + public <Q extends V> V addIfAbsent(Q newValue) { int h = newValue.w1; V[] table = directory[h & mask]; h >>>= SEGMENT_SHIFT; @@ -209,30 +186,38 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements return newValue; } - /** @return number of objects in this map. */ + /** + * Get number of objects in this map. + * + * @return number of objects in this map. + */ public int size() { return size; } - /** @return true if {@link #size()} is 0. */ + /** + * Whether this map is empty + * + * @return true if {@link #size()} is 0. + */ public boolean isEmpty() { return size == 0; } + @Override public Iterator<V> iterator() { - return new Iterator<V>() { + return new Iterator<>() { private int found; - private int dirIdx; - private int tblIdx; - private V next; + @Override public boolean hasNext() { return found < size; } + @Override public V next() { if (next != null) return found(next); @@ -261,6 +246,7 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements return v; } + @Override public void remove() { throw new UnsupportedOperationException(); } @@ -340,8 +326,8 @@ public class ObjectIdOwnerMap<V extends ObjectIdOwnerMap.Entry> implements } /** Type of entry stored in the {@link ObjectIdOwnerMap}. */ - public static abstract class Entry extends ObjectId { - Entry next; + public abstract static class Entry extends ObjectId { + transient Entry next; /** * Initialize this entry with a specific ObjectId. |