author | sundar |
Mon, 13 Oct 2014 23:38:49 +0530 | |
changeset 27099 | eceb216332cb |
parent 25865 | d38d876f1654 |
child 33690 | 46a1bc24cf2c |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package jdk.nashorn.internal.runtime; |
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import java.util.Arrays; |
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import java.util.Collection; |
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import java.util.Collections; |
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import java.util.HashSet; |
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import java.util.Map; |
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import java.util.Set; |
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/** |
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* Immutable hash map implementation for properties. Properties are keyed on strings. |
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* Copying and cloning is avoided by relying on immutability. |
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* <p> |
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* When adding an element to a hash table, only the head of a bin list is updated, thus |
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* an add only requires the cloning of the bins array and adding an element to the head |
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* of the bin list. Similarly for removal, only a portion of a bin list is updated. |
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* <p> |
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* A separate chronological list is kept for quick generation of keys and values, and, |
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* for rehashing. |
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* <p> |
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* Details: |
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* <p> |
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* The main goal is to be able to retrieve properties from a map quickly, keying on |
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* the property name (String.) A secondary, but important goal, is to keep maps |
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* immutable, so that a map can be shared by multiple objects in a context. |
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* Sharing maps allows objects to be categorized as having similar properties, a |
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* fact that call site guards rely on. In this discussion, immutability allows us |
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* to significantly reduce the amount of duplication we have in our maps. |
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* <p> |
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* The simplest of immutable maps is a basic singly linked list. New properties |
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* are simply added to the head of the list. Ancestor maps are not affected by the |
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* addition, since they continue to refer to their own head. Searching is done by |
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* walking linearly though the elements until a match is found, O(N). |
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* <p> |
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* A hash map can be thought of as an optimization of a linked list map, where the |
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* linked list is broken into fragments based on hashCode(key) . An array is use |
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* to quickly reference these fragments, indexing on hashCode(key) mod tableSize |
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* (tableSize is typically a power of 2 so that the mod is a fast masking |
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* operation.) If the size of the table is sufficient large, then search time |
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* approaches O(1). In fact, most bins in a hash table are typically empty or |
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* contain a one element list. |
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* <p> |
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* For immutable hash maps, we can think of the hash map as an array of the shorter |
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* linked list maps. If we add an element to the head of one of those lists, it |
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* doesn't affect any ancestor maps. Thus adding an element to an immutable hash |
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* map only requires cloning the array and inserting an element at the head of one |
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* of the bins. |
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* <p> |
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* Using Java HashMaps we don't have enough control over the entries to allow us to |
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* implement this technique, so we are forced to clone the entire hash map. |
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* <p> |
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* Removing elements is done similarly. We clone the array and then only modify |
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* the bin containing the removed element. More often than not, the list contains |
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* only one element (or is very short), so this is not very costly. When the list |
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* has several items, we need to clone the list portion prior to the removed item. |
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* <p> |
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* Another requirement of property maps is that we need to be able to gather all |
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* properties in chronological (add) order. We have been using LinkedHashMap to |
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* provide this. For the implementation of immutable hash map, we use a singly |
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* linked list that is linked in reverse chronological order. This means we simply |
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* add new entries to the head of the list. If we need to work with the list in |
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* forward order, it's simply a matter of allocating an array (size is known) and |
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* back filling in reverse order. Removal of elements from the chronological list |
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* is trickier. LinkedHashMap uses a doubly linked list to give constant time |
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* removal. Immutable hash maps can't do that and maintain immutability. So we |
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* manage the chronological list the same way we manage the bins, cloning up to the |
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* point of removal. Don't panic. This cost is more than offset by the cost of |
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* cloning an entire LinkedHashMap. Plus removal is far more rare than addition. |
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* <p> |
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* One more optimization. Maps with a small number of entries don't use the hash |
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* map at all, the chronological list is used instead. |
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* <p> |
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* So the benefits from immutable arrays are; fewer objects and less copying. For |
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* immutable hash map, when no removal is involved, the number of elements per |
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* property is two (bin + chronological elements). For LinkedHashMap it is one |
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* (larger element) times the number of maps that refer to the property. For |
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* immutable hash map, addition is constant time. For LinkedHashMap it's O(N+C) |
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* since we have to clone the older map. |
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*/ |
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public final class PropertyHashMap implements Map <String, Property> { |
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/** Number of initial bins. Power of 2. */ |
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private static final int INITIAL_BINS = 32; |
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/** Threshold before using bins. */ |
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private static final int LIST_THRESHOLD = 8; |
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/** Initial map. */ |
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public static final PropertyHashMap EMPTY_HASHMAP = new PropertyHashMap(); |
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/** Number of properties in the map. */ |
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private final int size; |
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/** Threshold before growing the bins. */ |
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private final int threshold; |
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/** Reverse list of all properties. */ |
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private final Element list; |
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/** Hash map bins. */ |
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private final Element[] bins; |
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/** All properties as an array (lazy). */ |
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private Property[] properties; |
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/** |
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* Empty map constructor. |
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*/ |
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private PropertyHashMap() { |
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this.size = 0; |
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this.threshold = 0; |
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this.bins = null; |
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this.list = null; |
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} |
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/** |
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* Clone Constructor |
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* |
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* @param map Original {@link PropertyHashMap}. |
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*/ |
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private PropertyHashMap(final PropertyHashMap map) { |
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this.size = map.size; |
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this.threshold = map.threshold; |
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this.bins = map.bins; |
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this.list = map.list; |
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} |
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/** |
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* Constructor used internally to extend a map |
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* |
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* @param size Size of the new {@link PropertyHashMap}. |
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* @param bins The hash bins. |
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* @param list The {@link Property} list. |
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*/ |
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private PropertyHashMap(final int size, final Element[] bins, final Element list) { |
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this.size = size; |
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this.threshold = bins != null ? threeQuarters(bins.length) : 0; |
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this.bins = bins; |
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this.list = list; |
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} |
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/** |
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* Clone a property map, replacing a property with a new one in the same place, |
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* which is important for property iterations if a property changes types |
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* @param property old property |
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* @param newProperty new property |
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* @return new property map |
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*/ |
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public PropertyHashMap immutableReplace(final Property property, final Property newProperty) { |
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assert property.getKey().equals(newProperty.getKey()) : "replacing properties with different keys: '" + property.getKey() + "' != '" + newProperty.getKey() + "'"; |
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assert findElement(property.getKey()) != null : "replacing property that doesn't exist in map: '" + property.getKey() + "'"; |
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return cloneMap().replaceNoClone(property.getKey(), newProperty); |
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} |
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/** |
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* Clone a {@link PropertyHashMap} and add a {@link Property}. |
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* |
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* @param property {@link Property} to add. |
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* |
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* @return New {@link PropertyHashMap}. |
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*/ |
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public PropertyHashMap immutableAdd(final Property property) { |
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final int newSize = size + 1; |
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PropertyHashMap newMap = cloneMap(newSize); |
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newMap = newMap.addNoClone(property); |
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return newMap; |
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} |
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/** |
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* Clone a {@link PropertyHashMap} and add an array of properties. |
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* |
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* @param newProperties Properties to add. |
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* |
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* @return New {@link PropertyHashMap}. |
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*/ |
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public PropertyHashMap immutableAdd(final Property... newProperties) { |
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final int newSize = size + newProperties.length; |
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PropertyHashMap newMap = cloneMap(newSize); |
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for (final Property property : newProperties) { |
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newMap = newMap.addNoClone(property); |
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} |
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return newMap; |
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} |
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/** |
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* Clone a {@link PropertyHashMap} and add a collection of properties. |
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* |
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* @param newProperties Properties to add. |
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* |
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* @return New {@link PropertyHashMap}. |
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*/ |
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public PropertyHashMap immutableAdd(final Collection<Property> newProperties) { |
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if (newProperties != null) { |
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final int newSize = size + newProperties.size(); |
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PropertyHashMap newMap = cloneMap(newSize); |
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for (final Property property : newProperties) { |
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newMap = newMap.addNoClone(property); |
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} |
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return newMap; |
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} |
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return this; |
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} |
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/** |
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* Clone a {@link PropertyHashMap} and remove a {@link Property}. |
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* |
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* @param property {@link Property} to remove. |
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* |
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* @return New {@link PropertyHashMap}. |
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*/ |
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public PropertyHashMap immutableRemove(final Property property) { |
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return immutableRemove(property.getKey()); |
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} |
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/** |
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* Clone a {@link PropertyHashMap} and remove a {@link Property} based on its key. |
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* |
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* @param key Key of {@link Property} to remove. |
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* |
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* @return New {@link PropertyHashMap}. |
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*/ |
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public PropertyHashMap immutableRemove(final String key) { |
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if (bins != null) { |
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final int binIndex = binIndex(bins, key); |
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final Element bin = bins[binIndex]; |
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if (findElement(bin, key) != null) { |
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final int newSize = size - 1; |
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Element[] newBins = null; |
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if (newSize >= LIST_THRESHOLD) { |
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newBins = bins.clone(); |
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newBins[binIndex] = removeFromList(bin, key); |
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} |
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final Element newList = removeFromList(list, key); |
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return new PropertyHashMap(newSize, newBins, newList); |
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} |
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} else if (findElement(list, key) != null) { |
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final int newSize = size - 1; |
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return newSize != 0 ? new PropertyHashMap(newSize, null, removeFromList(list, key)) : EMPTY_HASHMAP; |
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} |
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return this; |
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} |
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/** |
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* Find a {@link Property} in the {@link PropertyHashMap}. |
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* |
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* @param key Key of {@link Property} to find. |
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* |
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* @return {@link Property} matching key or {@code null} if not found. |
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*/ |
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public Property find(final String key) { |
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final Element element = findElement(key); |
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return element != null ? element.getProperty() : null; |
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} |
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/** |
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* Return an array of properties in chronological order of adding. |
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* |
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* @return Array of all properties. |
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*/ |
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Property[] getProperties() { |
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if (properties == null) { |
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final Property[] array = new Property[size]; |
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int i = size; |
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for (Element element = list; element != null; element = element.getLink()) { |
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array[--i] = element.getProperty(); |
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} |
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properties = array; |
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} |
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return properties; |
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} |
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/** |
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* Returns the bin index from the key. |
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* |
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* @param bins The bins array. |
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* @param key {@link Property} key. |
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* |
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* @return The bin index. |
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*/ |
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private static int binIndex(final Element[] bins, final String key) { |
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return key.hashCode() & bins.length - 1; |
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} |
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/** |
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* Calculate the number of bins needed to contain n properties. |
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* |
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* @param n Number of elements. |
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* |
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* @return Number of bins required. |
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*/ |
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private static int binsNeeded(final int n) { |
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// 50% padding |
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return 1 << 32 - Integer.numberOfLeadingZeros(n + (n >>> 1) | INITIAL_BINS - 1); |
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} |
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/** |
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* Used to calculate the current capacity of the bins. |
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* |
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* @param n Number of bin slots. |
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* |
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* @return 75% of n. |
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*/ |
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private static int threeQuarters(final int n) { |
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return (n >>> 1) + (n >>> 2); |
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} |
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/** |
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* Regenerate the bin table after changing the number of bins. |
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* |
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* @param list // List of all properties. |
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* @param binSize // New size of bins. |
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* |
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* @return Populated bins. |
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*/ |
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private static Element[] rehash(final Element list, final int binSize) { |
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final Element[] newBins = new Element[binSize]; |
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for (Element element = list; element != null; element = element.getLink()) { |
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final Property property = element.getProperty(); |
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final String key = property.getKey(); |
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final int binIndex = binIndex(newBins, key); |
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newBins[binIndex] = new Element(newBins[binIndex], property); |
347 |
} |
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return newBins; |
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} |
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/** |
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* Locate an element based on key. |
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* |
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* @param key {@link Element} key. |
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* |
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* @return {@link Element} matching key or {@code null} if not found. |
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*/ |
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358 |
private Element findElement(final String key) { |
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359 |
if (bins != null) { |
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final int binIndex = binIndex(bins, key); |
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return findElement(bins[binIndex], key); |
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} |
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return findElement(list, key); |
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} |
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/** |
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* Locate an {@link Element} based on key from a specific list. |
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* |
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* @param elementList Head of {@link Element} list |
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* @param key {@link Element} key. |
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* @return {@link Element} matching key or {@code null} if not found. |
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*/ |
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private static Element findElement(final Element elementList, final String key) { |
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final int hashCode = key.hashCode(); |
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for (Element element = elementList; element != null; element = element.getLink()) { |
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if (element.match(key, hashCode)) { |
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return element; |
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} |
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} |
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return null; |
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} |
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private PropertyHashMap cloneMap() { |
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return new PropertyHashMap(size, bins == null ? null : bins.clone(), list); |
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} |
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/** |
389 |
* Clone {@link PropertyHashMap} to accommodate new size. |
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* |
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391 |
* @param newSize New size of {@link PropertyHashMap}. |
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392 |
* |
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* @return Cloned {@link PropertyHashMap} with new size. |
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*/ |
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private PropertyHashMap cloneMap(final int newSize) { |
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396 |
Element[] newBins; |
|
397 |
if (bins == null && newSize <= LIST_THRESHOLD) { |
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398 |
newBins = null; |
|
399 |
} else if (newSize > threshold) { |
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16758
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8011095: PropertyHashMap.rehash() does not grow enough
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16205
diff
changeset
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400 |
newBins = rehash(list, binsNeeded(newSize)); |
16147 | 401 |
} else { |
402 |
newBins = bins.clone(); |
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403 |
} |
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return new PropertyHashMap(newSize, newBins, list); |
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405 |
} |
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24719 | 407 |
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408 |
||
16147 | 409 |
/** |
410 |
* Add a {@link Property} to a temporary {@link PropertyHashMap}, that has |
|
411 |
* been already cloned. Removes duplicates if necessary. |
|
412 |
* |
|
413 |
* @param property {@link Property} to add. |
|
414 |
* |
|
415 |
* @return New {@link PropertyHashMap}. |
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416 |
*/ |
|
417 |
private PropertyHashMap addNoClone(final Property property) { |
|
418 |
int newSize = size; |
|
419 |
final String key = property.getKey(); |
|
420 |
Element newList = list; |
|
421 |
if (bins != null) { |
|
422 |
final int binIndex = binIndex(bins, key); |
|
423 |
Element bin = bins[binIndex]; |
|
424 |
if (findElement(bin, key) != null) { |
|
425 |
newSize--; |
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426 |
bin = removeFromList(bin, key); |
|
427 |
newList = removeFromList(list, key); |
|
428 |
} |
|
429 |
bins[binIndex] = new Element(bin, property); |
|
430 |
} else { |
|
431 |
if (findElement(list, key) != null) { |
|
432 |
newSize--; |
|
433 |
newList = removeFromList(list, key); |
|
434 |
} |
|
435 |
} |
|
436 |
newList = new Element(newList, property); |
|
437 |
return new PropertyHashMap(newSize, bins, newList); |
|
438 |
} |
|
439 |
||
24719 | 440 |
private PropertyHashMap replaceNoClone(final String key, final Property property) { |
441 |
if (bins != null) { |
|
442 |
final int binIndex = binIndex(bins, key); |
|
443 |
Element bin = bins[binIndex]; |
|
444 |
bin = replaceInList(bin, key, property); |
|
445 |
bins[binIndex] = bin; |
|
446 |
} |
|
447 |
Element newList = list; |
|
448 |
newList = replaceInList(newList, key, property); |
|
449 |
return new PropertyHashMap(size, bins, newList); |
|
450 |
} |
|
451 |
||
16147 | 452 |
/** |
453 |
* Removes an {@link Element} from a specific list, avoiding duplication. |
|
454 |
* |
|
455 |
* @param list List to remove from. |
|
456 |
* @param key Key of {@link Element} to remove. |
|
457 |
* |
|
458 |
* @return New list with {@link Element} removed. |
|
459 |
*/ |
|
460 |
private static Element removeFromList(final Element list, final String key) { |
|
461 |
if (list == null) { |
|
462 |
return null; |
|
463 |
} |
|
464 |
final int hashCode = key.hashCode(); |
|
465 |
if (list.match(key, hashCode)) { |
|
466 |
return list.getLink(); |
|
467 |
} |
|
468 |
final Element head = new Element(null, list.getProperty()); |
|
469 |
Element previous = head; |
|
470 |
for (Element element = list.getLink(); element != null; element = element.getLink()) { |
|
471 |
if (element.match(key, hashCode)) { |
|
472 |
previous.setLink(element.getLink()); |
|
473 |
return head; |
|
474 |
} |
|
475 |
final Element next = new Element(null, element.getProperty()); |
|
476 |
previous.setLink(next); |
|
477 |
previous = next; |
|
478 |
} |
|
479 |
return list; |
|
480 |
} |
|
481 |
||
24719 | 482 |
// for element x. if x get link matches, |
483 |
private static Element replaceInList(final Element list, final String key, final Property property) { |
|
484 |
assert list != null; |
|
485 |
final int hashCode = key.hashCode(); |
|
486 |
||
487 |
if (list.match(key, hashCode)) { |
|
488 |
return new Element(list.getLink(), property); |
|
489 |
} |
|
490 |
||
24734
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
491 |
final Element head = new Element(null, list.getProperty()); |
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
492 |
Element previous = head; |
24719 | 493 |
for (Element element = list.getLink(); element != null; element = element.getLink()) { |
494 |
if (element.match(key, hashCode)) { |
|
495 |
previous.setLink(new Element(element.getLink(), property)); |
|
24734
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
496 |
return head; |
24719 | 497 |
} |
24734
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
498 |
final Element next = new Element(null, element.getProperty()); |
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
499 |
previous.setLink(next); |
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
500 |
previous = next; |
24719 | 501 |
} |
502 |
return list; |
|
503 |
} |
|
504 |
||
505 |
||
16147 | 506 |
/* |
507 |
* Map implementation |
|
508 |
*/ |
|
509 |
||
510 |
@Override |
|
511 |
public int size() { |
|
512 |
return size; |
|
513 |
} |
|
514 |
||
515 |
@Override |
|
516 |
public boolean isEmpty() { |
|
517 |
return size == 0; |
|
518 |
} |
|
519 |
||
520 |
@Override |
|
521 |
public boolean containsKey(final Object key) { |
|
522 |
if (key instanceof String) { |
|
523 |
return findElement((String)key) != null; |
|
524 |
} |
|
525 |
assert key instanceof String; |
|
526 |
return false; |
|
527 |
} |
|
528 |
||
529 |
/** |
|
530 |
* Check if the map contains a key. |
|
531 |
* |
|
532 |
* @param key {@link Property} key. |
|
533 |
* |
|
534 |
* @return {@code true} of key is in {@link PropertyHashMap}. |
|
535 |
*/ |
|
536 |
public boolean containsKey(final String key) { |
|
537 |
return findElement(key) != null; |
|
538 |
} |
|
539 |
||
540 |
@Override |
|
541 |
public boolean containsValue(final Object value) { |
|
542 |
if (value instanceof Property) { |
|
543 |
final Property property = (Property) value; |
|
544 |
final Element element = findElement(property.getKey()); |
|
545 |
return element != null && element.getProperty().equals(value); |
|
546 |
} |
|
547 |
return false; |
|
548 |
} |
|
549 |
||
550 |
@Override |
|
551 |
public Property get(final Object key) { |
|
552 |
if (key instanceof String) { |
|
553 |
final Element element = findElement((String)key); |
|
554 |
return element != null ? element.getProperty() : null; |
|
555 |
} |
|
556 |
assert key instanceof String; |
|
557 |
return null; |
|
558 |
} |
|
559 |
||
560 |
/** |
|
561 |
* Get the {@link Property} given a key that is an explicit {@link String}. |
|
562 |
* See also {@link PropertyHashMap#get(Object)} |
|
563 |
* |
|
564 |
* @param key {@link Property} key. |
|
565 |
* |
|
566 |
* @return {@link Property}, or {@code null} if no property with that key was found. |
|
567 |
*/ |
|
568 |
public Property get(final String key) { |
|
569 |
final Element element = findElement(key); |
|
570 |
return element != null ? element.getProperty() : null; |
|
571 |
} |
|
572 |
||
573 |
@Override |
|
574 |
public Property put(final String key, final Property value) { |
|
575 |
throw new UnsupportedOperationException("Immutable map."); |
|
576 |
} |
|
577 |
||
578 |
@Override |
|
579 |
public Property remove(final Object key) { |
|
580 |
throw new UnsupportedOperationException("Immutable map."); |
|
581 |
} |
|
582 |
||
583 |
@Override |
|
584 |
public void putAll(final Map<? extends String, ? extends Property> m) { |
|
585 |
throw new UnsupportedOperationException("Immutable map."); |
|
586 |
} |
|
587 |
||
588 |
@Override |
|
589 |
public void clear() { |
|
590 |
throw new UnsupportedOperationException("Immutable map."); |
|
591 |
} |
|
592 |
||
593 |
@Override |
|
594 |
public Set<String> keySet() { |
|
595 |
final HashSet<String> set = new HashSet<>(); |
|
596 |
for (Element element = list; element != null; element = element.getLink()) { |
|
597 |
set.add(element.getKey()); |
|
598 |
} |
|
599 |
return Collections.unmodifiableSet(set); |
|
600 |
} |
|
601 |
||
602 |
@Override |
|
603 |
public Collection<Property> values() { |
|
604 |
return Collections.unmodifiableList(Arrays.asList(getProperties())); |
|
605 |
} |
|
606 |
||
607 |
@Override |
|
608 |
public Set<Entry<String, Property>> entrySet() { |
|
609 |
final HashSet<Entry<String, Property>> set = new HashSet<>(); |
|
610 |
for (Element element = list; element != null; element = element.getLink()) { |
|
611 |
set.add(element); |
|
612 |
} |
|
613 |
return Collections.unmodifiableSet(set); |
|
614 |
} |
|
615 |
||
616 |
/** |
|
617 |
* List map element. |
|
618 |
*/ |
|
619 |
static final class Element implements Entry<String, Property> { |
|
620 |
/** Link for list construction. */ |
|
621 |
private Element link; |
|
622 |
||
623 |
/** Element property. */ |
|
624 |
private final Property property; |
|
625 |
||
626 |
/** Element key. Kept separate for performance.) */ |
|
627 |
private final String key; |
|
628 |
||
629 |
/** Element key hash code. */ |
|
630 |
private final int hashCode; |
|
631 |
||
632 |
/* |
|
633 |
* Constructors |
|
634 |
*/ |
|
635 |
||
636 |
Element(final Element link, final Property property) { |
|
637 |
this.link = link; |
|
638 |
this.property = property; |
|
639 |
this.key = property.getKey(); |
|
640 |
this.hashCode = this.key.hashCode(); |
|
641 |
} |
|
642 |
||
643 |
boolean match(final String otherKey, final int otherHashCode) { |
|
644 |
return this.hashCode == otherHashCode && this.key.equals(otherKey); |
|
645 |
} |
|
646 |
||
647 |
/* |
|
648 |
* Entry implmentation. |
|
649 |
*/ |
|
650 |
||
651 |
@Override |
|
652 |
public boolean equals(final Object other) { |
|
653 |
assert property != null && other != null; |
|
16179
5b8bcfd712d3
8006517: PropertyHashMap.Element.equals() compares to Property
jlaskey
parents:
16151
diff
changeset
|
654 |
return other instanceof Element && property.equals(((Element)other).property); |
16147 | 655 |
} |
656 |
||
657 |
@Override |
|
658 |
public String getKey() { |
|
659 |
return key; |
|
660 |
} |
|
661 |
||
662 |
@Override |
|
663 |
public Property getValue() { |
|
664 |
return property; |
|
665 |
} |
|
666 |
||
667 |
@Override |
|
668 |
public int hashCode() { |
|
669 |
return hashCode; |
|
670 |
} |
|
671 |
||
672 |
@Override |
|
673 |
public Property setValue(final Property value) { |
|
674 |
throw new UnsupportedOperationException("Immutable map."); |
|
675 |
} |
|
676 |
||
24719 | 677 |
@Override |
678 |
public String toString() { |
|
679 |
final StringBuffer sb = new StringBuffer(); |
|
680 |
||
681 |
sb.append('['); |
|
682 |
||
683 |
Element elem = this; |
|
684 |
do { |
|
24734
da070553a8e1
8038799: Guard and unbox boxed primitives types on setting them in Properties to avoid megamorphisism
lagergren
parents:
24720
diff
changeset
|
685 |
sb.append(elem.getValue()); |
24719 | 686 |
elem = elem.link; |
687 |
if (elem != null) { |
|
688 |
sb.append(" -> "); |
|
689 |
} |
|
690 |
} while (elem != null); |
|
691 |
||
692 |
sb.append(']'); |
|
693 |
||
694 |
return sb.toString(); |
|
695 |
} |
|
696 |
||
16147 | 697 |
/* |
698 |
* Accessors |
|
699 |
*/ |
|
700 |
||
701 |
Element getLink() { |
|
702 |
return link; |
|
703 |
} |
|
704 |
||
705 |
void setLink(final Element link) { |
|
706 |
this.link = link; |
|
707 |
} |
|
708 |
||
709 |
Property getProperty() { |
|
710 |
return property; |
|
711 |
} |
|
712 |
} |
|
713 |
||
714 |
} |