/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright (c) 2010-2015 Oracle and/or its affiliates. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License"). You * may not use this file except in compliance with the License. You can * obtain a copy of the License at * http://glassfish.java.net/public/CDDL+GPL_1_1.html * or packager/legal/LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at packager/legal/LICENSE.txt. * * GPL Classpath Exception: * Oracle designates this particular file as subject to the "Classpath" * exception as provided by Oracle in the GPL Version 2 section of the License * file that accompanied this code. * * Modifications: * If applicable, add the following below the License Header, with the fields * enclosed by brackets [] replaced by your own identifying information: * "Portions Copyright [year] [name of copyright owner]" * * Contributor(s): * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package org.glassfish.jersey.internal.util.collection; import java.io.IOException; import java.io.Serializable; import java.util.AbstractMap; import java.util.AbstractSet; import java.util.ConcurrentModificationException; import java.util.Iterator; import java.util.Map; import java.util.NoSuchElementException; import java.util.Set; import org.glassfish.jersey.internal.LocalizationMessages; /** * A implementation similar to {@link java.util.HashMap} but supports the * comparison of keys using a {@link KeyComparator}. * * @param <K> Type of keys * @param <V> Type of values * @author Paul Sandoz */ @SuppressWarnings("unchecked") public class KeyComparatorHashMap<K, V> extends AbstractMap<K, V> implements Map<K, V>, Cloneable, Serializable { private static final long serialVersionUID = 3000273665665137463L; /** * The default initial capacity - MUST be a power of two. */ static final int DEFAULT_INITIAL_CAPACITY = 16; /** * The maximum capacity, used if a higher value is implicitly specified * by either of the constructors with arguments. * MUST be a power of two <= 1<<30. */ static final int MAXIMUM_CAPACITY = 1 << 30; /** * The load factor used when none specified in constructor. */ static final float DEFAULT_LOAD_FACTOR = 0.75f; /** * The table, resized as necessary. Length MUST Always be a power of two. */ transient Entry<K, V>[] table; /** * The number of key-value mappings contained in this identity hash map. */ transient int size; /** * The next ss value at which to resize (capacity * load factor). * * @serial */ int threshold; /** * The load factor for the hash table. * * @serial */ final float loadFactor; /** * The number of times this HashMap has been structurally modified * Structural modifications are those that change the number of mappings in * the HashMap or otherwise modify its internal structure (e.g., * rehash). This field is used to make iterators on Collection-views of * the HashMap fail-fast. (See ConcurrentModificationException). */ transient volatile int modCount; final KeyComparator<K> keyComparator; /** * Constructs an empty <tt>HashMap</tt> with the specified initial * capacity and load factor. * * @param initialCapacity The initial capacity. * @param loadFactor The load factor. * @param keyComparator the map key comparator. * @throws IllegalArgumentException if the initial capacity is negative * or the load factor is nonpositive. */ @SuppressWarnings("unchecked") public KeyComparatorHashMap(int initialCapacity, final float loadFactor, final KeyComparator<K> keyComparator) { if (initialCapacity < 0) { throw new IllegalArgumentException(LocalizationMessages.ILLEGAL_INITIAL_CAPACITY(initialCapacity)); } if (initialCapacity > MAXIMUM_CAPACITY) { initialCapacity = MAXIMUM_CAPACITY; } if (loadFactor <= 0 || Float.isNaN(loadFactor)) { throw new IllegalArgumentException(LocalizationMessages.ILLEGAL_LOAD_FACTOR(loadFactor)); } // Find a power of 2 >= initialCapacity int capacity = 1; while (capacity < initialCapacity) { capacity <<= 1; } this.loadFactor = loadFactor; threshold = (int) (capacity * loadFactor); table = new Entry[capacity]; this.keyComparator = keyComparator; init(); } /** * Constructs an empty <tt>HashMap</tt> with the specified initial * capacity and the default load factor (0.75). * * @param initialCapacity the initial capacity. * @param keyComparator the map key comparator. * @throws IllegalArgumentException if the initial capacity is negative. */ @SuppressWarnings("unchecked") public KeyComparatorHashMap(final int initialCapacity, final KeyComparator<K> keyComparator) { this(initialCapacity, DEFAULT_LOAD_FACTOR, keyComparator); } /** * Constructs an empty <tt>HashMap</tt> with the default initial capacity * (16) and the default load factor (0.75). * * @param keyComparator the map key comparator. */ public KeyComparatorHashMap(final KeyComparator<K> keyComparator) { this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, keyComparator); } /** * Constructs a new <tt>HashMap</tt> with the same mappings as the * specified <tt>Map</tt>. The <tt>HashMap</tt> is created with * default load factor (0.75) and an initial capacity sufficient to * hold the mappings in the specified <tt>Map</tt>. * * @param m the map whose mappings are to be placed in this map. * @param keyComparator the comparator * @throws NullPointerException if the specified map is null. */ public KeyComparatorHashMap(final Map<? extends K, ? extends V> m, final KeyComparator<K> keyComparator) { this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1, DEFAULT_INITIAL_CAPACITY), DEFAULT_LOAD_FACTOR, keyComparator); putAllForCreate(m); } /** * Get the number of times this HashMap has been structurally modified * Structural modifications are those that change the number of mappings in * the HashMap or otherwise modify its internal structure (e.g., * rehash). * * @return return the modification count. */ public int getModCount() { return modCount; } // internal utilities /** * Initialization hook for subclasses. * <p/> * This method is called in all pseudo-constructors (clone, readObject) * after HashMap has been initialized but before any entries have * been inserted. (In the absence of this method, readObject would * require explicit knowledge of subclasses.) */ void init() { } /** * Value representing null keys inside tables. */ static final Object NULL_KEY = new Object(); /** * Returns internal representation for key. Use NULL_KEY if key is null. */ static <T> T maskNull(final T key) { return key == null ? (T) NULL_KEY : key; } static <T> boolean isNull(final T key) { return key == NULL_KEY; } /** * Returns key represented by specified internal representation. */ static <T> T unmaskNull(final T key) { return key == NULL_KEY ? null : key; } /** * Returns a hash value for the specified object. In addition to * the object's own hashCode, this method applies a "supplemental * hash function," which defends against poor quality hash functions. * This is critical because HashMap uses power-of two length * hash tables.<p> * <p/> * The shift distances in this function were chosen as the result * of an automated search over the entire four-dimensional search space. */ static int hash(final Object x) { int h = x.hashCode(); h += ~(h << 9); h ^= (h >>> 14); h += (h << 4); h ^= (h >>> 10); return h; } /** * Check for equality of non-null reference x and possibly-null y. */ static boolean eq(final Object x, final Object y) { return x == y || x.equals(y); } /** * Returns index for hash code h. */ static int indexFor(final int h, final int length) { return h & (length - 1); } /** * Returns the number of key-value mappings in this map. * * @return the number of key-value mappings in this map. */ @Override public int size() { return size; } /** * Returns <tt>true</tt> if this map contains no key-value mappings. * * @return <tt>true</tt> if this map contains no key-value mappings. */ @Override public boolean isEmpty() { return size == 0; } int keyComparatorHash(final K k) { return isNull(k) ? hash(k.hashCode()) : hash(keyComparator.hash(k)); } int hash(int h) { h += ~(h << 9); h ^= (h >>> 14); h += (h << 4); h ^= (h >>> 10); return h; } /** * Check for equality of non-null reference x and possibly-null y. */ boolean keyComparatorEq(final K x, final K y) { if (isNull(x)) { return x == y; } else if (isNull(y)) { return x == y; } else { return x == y || keyComparator.equals(x, y); } } /** * Returns the value to which the specified key is mapped in this identity * hash map, or <tt>null</tt> if the map contains no mapping for this key. * A return value of <tt>null</tt> does not <i>necessarily</i> indicate * that the map contains no mapping for the key; it is also possible that * the map explicitly maps the key to <tt>null</tt>. The * <tt>containsKey</tt> method may be used to distinguish these two cases. * * @param key the key whose associated value is to be returned. * @return the value to which this map maps the specified key, or * <tt>null</tt> if the map contains no mapping for this key. * @see #put(Object, Object) */ @Override public V get(final Object key) { final K k = (K) maskNull(key); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); Entry<K, V> e = table[i]; while (true) { if (e == null) { return null; } if (e.hash == hash && keyComparatorEq(k, e.key)) { return e.value; } e = e.next; } } /** * Returns <tt>true</tt> if this map contains a mapping for the * specified key. * * @param key The key whose presence in this map is to be tested * @return <tt>true</tt> if this map contains a mapping for the specified * key. */ @Override public boolean containsKey(final Object key) { final K k = (K) maskNull(key); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); Entry<K, V> e = table[i]; while (e != null) { if (e.hash == hash && keyComparatorEq(k, e.key)) { return true; } e = e.next; } return false; } /** * Returns the entry associated with the specified key in the * HashMap. Returns null if the HashMap contains no mapping * for this key. */ Entry<K, V> getEntry(final K key) { final K k = maskNull(key); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); Entry<K, V> e = table[i]; while (e != null && !(e.hash == hash && keyComparatorEq(k, e.key))) { e = e.next; } return e; } /** * Associates the specified value with the specified key in this map. * If the map previously contained a mapping for this key, the old * value is replaced. * * @param key key with which the specified value is to be associated. * @param value value to be associated with the specified key. * @return previous value associated with specified key, or <tt>null</tt> * if there was no mapping for key. A <tt>null</tt> return can * also indicate that the HashMap previously associated * <tt>null</tt> with the specified key. */ @Override public V put(final K key, final V value) { final K k = maskNull(key); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); for (Entry<K, V> e = table[i]; e != null; e = e.next) { if (e.hash == hash && keyComparatorEq(k, e.key)) { final V oldValue = e.value; e.value = value; e.recordAccess(this); return oldValue; } } modCount++; addEntry(hash, k, value, i); return null; } /** * This method is used instead of put by constructors and * pseudoconstructors (clone, readObject). It does not resize the table, * check for comodification, etc. It calls createEntry rather than * addEntry. */ private void putForCreate(final K key, final V value) { final K k = maskNull(key); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); /** * Look for preexisting entry for key. This will never happen for * clone or de-serialize. It will only happen for construction if the * input Map is a sorted map whose ordering is inconsistent w/ equals. */ for (Entry<K, V> e = table[i]; e != null; e = e.next) { if (e.hash == hash && keyComparatorEq(k, e.key)) { e.value = value; return; } } createEntry(hash, k, value, i); } private void putAllForCreate(final Map<? extends K, ? extends V> m) { for (final Map.Entry<? extends K, ? extends V> e : m.entrySet()) { putForCreate(e.getKey(), e.getValue()); } } /** * Rehashes the contents of this map into a new array with a * larger capacity. This method is called automatically when the * number of keys in this map reaches its threshold. * <p/> * If current capacity is MAXIMUM_CAPACITY, this method does not * resize the map, but sets threshold to Integer.MAX_VALUE. * This has the effect of preventing future calls. * * @param newCapacity the new capacity, MUST be a power of two; * must be greater than current capacity unless current * capacity is MAXIMUM_CAPACITY (in which case value * is irrelevant). */ void resize(final int newCapacity) { final Entry<K, V>[] oldTable = table; final int oldCapacity = oldTable.length; if (oldCapacity == MAXIMUM_CAPACITY) { threshold = Integer.MAX_VALUE; return; } final Entry<K, V>[] newTable = new Entry[newCapacity]; transfer(newTable); table = newTable; threshold = (int) (newCapacity * loadFactor); } /** * Transfer all entries from current table to newTable. */ void transfer(final Entry<K, V>[] newTable) { final Entry<K, V>[] src = table; final int newCapacity = newTable.length; for (int j = 0; j < src.length; j++) { Entry<K, V> e = src[j]; if (e != null) { src[j] = null; do { final Entry<K, V> next = e.next; final int i = indexFor(e.hash, newCapacity); e.next = newTable[i]; newTable[i] = e; e = next; } while (e != null); } } } /** * Copies all of the mappings from the specified map to this map * These mappings will replace any mappings that * this map had for any of the keys currently in the specified map. * * @param m mappings to be stored in this map. * @throws NullPointerException if the specified map is null. */ @Override public void putAll(final Map<? extends K, ? extends V> m) { final int numKeysToBeAdded = m.size(); if (numKeysToBeAdded == 0) { return; } /* * Expand the map if the map if the number of mappings to be added * is greater than or equal to threshold. This is conservative; the * obvious condition is (m.ss() + ss) >= threshold, but this * condition could result in a map with twice the appropriate capacity, * if the keys to be added overlap with the keys already in this map. * By using the conservative calculation, we subject ourself * to at most one extra resize. */ if (numKeysToBeAdded > threshold) { int targetCapacity = (int) (numKeysToBeAdded / loadFactor + 1); if (targetCapacity > MAXIMUM_CAPACITY) { targetCapacity = MAXIMUM_CAPACITY; } int newCapacity = table.length; while (newCapacity < targetCapacity) { newCapacity <<= 1; } if (newCapacity > table.length) { resize(newCapacity); } } for (final Map.Entry<? extends K, ? extends V> e : m.entrySet()) { put(e.getKey(), e.getValue()); } } /** * Removes the mapping for this key from this map if present. * * @param key key whose mapping is to be removed from the map. * @return previous value associated with specified key, or <tt>null</tt> * if there was no mapping for key. A <tt>null</tt> return can * also indicate that the map previously associated <tt>null</tt> * with the specified key. */ @Override public V remove(final Object key) { final Entry<K, V> e = removeEntryForKey(key); return (e == null ? null : e.value); } /** * Removes and returns the entry associated with the specified key * in the HashMap. Returns null if the HashMap contains no mapping * for this key. */ Entry<K, V> removeEntryForKey(final Object key) { final K k = (K) maskNull(key); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); Entry<K, V> prev = table[i]; Entry<K, V> e = prev; while (e != null) { final Entry<K, V> next = e.next; if (e.hash == hash && keyComparatorEq(k, e.key)) { modCount++; size--; if (prev == e) { table[i] = next; } else { prev.next = next; } e.recordRemoval(this); return e; } prev = e; e = next; } return e; } /** * Special version of remove for EntrySet. */ Entry<K, V> removeMapping(final Object o) { if (!(o instanceof Map.Entry)) { return null; } final Map.Entry<K, V> entry = (Map.Entry<K, V>) o; final K k = maskNull(entry.getKey()); final int hash = keyComparatorHash(k); final int i = indexFor(hash, table.length); Entry<K, V> prev = table[i]; Entry<K, V> e = prev; while (e != null) { final Entry<K, V> next = e.next; if (e.hash == hash && e.equals(entry)) { modCount++; size--; if (prev == e) { table[i] = next; } else { prev.next = next; } e.recordRemoval(this); return e; } prev = e; e = next; } return e; } /** * Removes all mappings from this map. */ @Override public void clear() { modCount++; final Entry[] tab = table; for (int i = 0; i < tab.length; i++) { tab[i] = null; } size = 0; } /** * Returns <tt>true</tt> if this map maps one or more keys to the * specified value. * * @param value value whose presence in this map is to be tested. * @return <tt>true</tt> if this map maps one or more keys to the * specified value. */ @Override public boolean containsValue(final Object value) { if (value == null) { return containsNullValue(); } final Entry[] tab = table; for (int i = 0; i < tab.length; i++) { for (Entry e = tab[i]; e != null; e = e.next) { if (value.equals(e.value)) { return true; } } } return false; } /** * Special-case code for containsValue with null argument */ private boolean containsNullValue() { final Entry[] tab = table; for (final Entry aTab : tab) { for (Entry e = aTab; e != null; e = e.next) { if (e.value == null) { return true; } } } return false; } /** * Returns a shallow copy of this <tt>HashMap</tt> instance: the keys and * values themselves are not cloned. * * @return a shallow copy of this map. */ @Override public Object clone() { KeyComparatorHashMap<K, V> result = null; try { result = (KeyComparatorHashMap<K, V>) super.clone(); result.table = new Entry[table.length]; result.entrySet = null; result.modCount = 0; result.size = 0; result.init(); result.putAllForCreate(this); } catch (final CloneNotSupportedException e) { // assert false; } return result; } static class Entry<K, V> implements Map.Entry<K, V> { final K key; V value; final int hash; Entry<K, V> next; /** * Create new entry. */ Entry(final int h, final K k, final V v, final Entry<K, V> n) { value = v; next = n; key = k; hash = h; } @Override public K getKey() { return KeyComparatorHashMap.<K>unmaskNull(key); } @Override public V getValue() { return value; } @Override public V setValue(final V newValue) { final V oldValue = value; value = newValue; return oldValue; } @Override public boolean equals(final Object o) { if (!(o instanceof Map.Entry)) { return false; } final Map.Entry e = (Map.Entry) o; final Object k1 = getKey(); final Object k2 = e.getKey(); if (k1 == k2 || (k1 != null && k1.equals(k2))) { final Object v1 = getValue(); final Object v2 = e.getValue(); if (v1 == v2 || (v1 != null && v1.equals(v2))) { return true; } } return false; } @Override public int hashCode() { return (key == NULL_KEY ? 0 : key.hashCode()) ^ (value == null ? 0 : value.hashCode()); } @Override public String toString() { return getKey() + "=" + getValue(); } /** * This method is invoked whenever the value in an entry is * overwritten by an invocation of put(k,v) for a key k that's already * in the HashMap. */ void recordAccess(final KeyComparatorHashMap<K, V> m) { } /** * This method is invoked whenever the entry is * removed from the table. */ void recordRemoval(final KeyComparatorHashMap<K, V> m) { } } /** * Add a new entry with the specified key, value and hash code to * the specified bucket. It is the responsibility of this * method to resize the table if appropriate. * <p/> * Subclass overrides this to alter the behavior of put method. */ void addEntry(final int hash, final K key, final V value, final int bucketIndex) { final Entry<K, V> e = table[bucketIndex]; table[bucketIndex] = new Entry<K, V>(hash, key, value, e); if (size++ >= threshold) { resize(2 * table.length); } } /** * Like addEntry except that this version is used when creating entries * as part of Map construction or "pseudo-construction" (cloning, * deserialization). This version needn't worry about resizing the table. * <p/> * Subclass overrides this to alter the behavior of HashMap(Map), * clone, and readObject. */ void createEntry(final int hash, final K key, final V value, final int bucketIndex) { final Entry<K, V> e = table[bucketIndex]; table[bucketIndex] = new Entry<K, V>(hash, key, value, e); size++; } private abstract class HashIterator<E> implements Iterator<E> { Entry<K, V> next; // next entry to return int expectedModCount; // For fast-fail int index; // current slot Entry<K, V> current; // current entry HashIterator() { expectedModCount = modCount; final Entry<K, V>[] t = table; int i = t.length; Entry<K, V> n = null; if (size != 0) { // advance to first entry //noinspection StatementWithEmptyBody while (i > 0 && (n = t[--i]) == null) { } } next = n; index = i; } @Override public boolean hasNext() { return next != null; } Entry<K, V> nextEntry() { if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } final Entry<K, V> e = next; if (e == null) { throw new NoSuchElementException(); } Entry<K, V> n = e.next; final Entry<K, V>[] t = table; int i = index; while (n == null && i > 0) { n = t[--i]; } index = i; next = n; return current = e; } @Override public void remove() { if (current == null) { throw new IllegalStateException(); } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } final K k = current.key; current = null; KeyComparatorHashMap.this.removeEntryForKey(k); expectedModCount = modCount; } } private class ValueIterator extends HashIterator<V> { @Override public V next() { return nextEntry().value; } } private class KeyIterator extends HashIterator<K> { @Override public K next() { return nextEntry().getKey(); } } private class EntryIterator extends HashIterator<Map.Entry<K, V>> { @Override public Map.Entry<K, V> next() { return nextEntry(); } } // Subclass overrides these to alter behavior of views' iterator() method Iterator<K> newKeyIterator() { return new KeyIterator(); } Iterator<V> newValueIterator() { return new ValueIterator(); } Iterator<Map.Entry<K, V>> newEntryIterator() { return new EntryIterator(); } // Views private transient Set<Map.Entry<K, V>> entrySet = null; /** * Returns a collection view of the mappings contained in this map. Each * element in the returned collection is a <tt>Map.Entry</tt>. The * collection is backed by the map, so changes to the map are reflected in * the collection, and vice-versa. The collection supports element * removal, which removes the corresponding mapping from the map, via the * <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>, * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations. * It does not support the <tt>add</tt> or <tt>addAll</tt> operations. * * @return a collection view of the mappings contained in this map. */ @Override public Set<Map.Entry<K, V>> entrySet() { final Set<Map.Entry<K, V>> es = entrySet; return (es != null ? es : (entrySet = (Set<Map.Entry<K, V>>) new EntrySet())); } private class EntrySet extends AbstractSet/*<Map.Entry<K,V>>*/ { @Override public Iterator/*<Map.Entry<K,V>>*/ iterator() { return newEntryIterator(); } @Override public boolean contains(final Object o) { if (!(o instanceof Map.Entry)) { return false; } final Map.Entry<K, V> e = (Map.Entry<K, V>) o; final Entry<K, V> candidate = getEntry(e.getKey()); return candidate != null && candidate.equals(e); } @Override public boolean remove(final Object o) { return removeMapping(o) != null; } @Override public int size() { return size; } @Override public void clear() { KeyComparatorHashMap.this.clear(); } } /** * Save the state of the <tt>HashMap</tt> instance to a stream (i.e., * serialize it). * * @serialData The <i>capacity</i> of the HashMap (the length of the * bucket array) is emitted (int), followed by the * <i>ss</i> of the HashMap (the number of key-value * mappings), followed by the key (Object) and value (Object) * for each key-value mapping represented by the HashMap * The key-value mappings are emitted in the order that they * are returned by <tt>entrySet().iterator()</tt>. */ private void writeObject(final java.io.ObjectOutputStream s) throws IOException { final Iterator<Map.Entry<K, V>> i = entrySet().iterator(); // Write out the threshold, loadfactor, and any hidden stuff s.defaultWriteObject(); // Write out number of buckets s.writeInt(table.length); // Write out ss (number of Mappings) s.writeInt(size); // Write out keys and values (alternating) while (i.hasNext()) { final Map.Entry<K, V> e = i.next(); s.writeObject(e.getKey()); s.writeObject(e.getValue()); } } /** * Reconstitute the <tt>HashMap</tt> instance from a stream (i.e., * deserialize it). */ private void readObject(final java.io.ObjectInputStream s) throws IOException, ClassNotFoundException { // Read in the threshold, loadfactor, and any hidden stuff s.defaultReadObject(); // Read in number of buckets and allocate the bucket array; final int numBuckets = s.readInt(); table = new Entry[numBuckets]; init(); // Give subclass a chance to do its thing. // Read in ss (number of Mappings) final int ss = s.readInt(); // Read the keys and values, and put the mappings in the HashMap for (int i = 0; i < ss; i++) { final K key = (K) s.readObject(); final V value = (V) s.readObject(); putForCreate(key, value); } } // These methods are used when serializing HashSets int capacity() { return table.length; } float loadFactor() { return loadFactor; } }