/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional information regarding
* copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License. You may obtain a
* copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package org.apache.geode.cache.query.internal;
import java.io.IOException;
import java.io.Serializable;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Collections;
import java.util.ConcurrentModificationException;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.TreeMap;
/**
* This class was derived from <tt>HashMap<tt> implementation of the
* <tt>Map</tt> interface. This implementation provides all of the optional map operations, and
* supports ONLY int primitive type values, stored in primitive field of int type instead of
* promoting them to Integer and the <tt>null</tt> key. The default for a value is 0. (The
* <tt>ObjectIntHashMap</tt> class is roughly equivalent to <tt>HashMap</tt>, except that it is
* unsynchronized and permits nulls.) This class makes no guarantees as to the order of the map; in
* particular, it does not guarantee that the order will remain constant over time.
*
* <p>
* This implementation provides constant-time performance for the basic operations (<tt>get</tt> and
* <tt>put</tt>), assuming the hash function disperses the elements properly among the buckets.
* Iteration over collection views requires time proportional to the "capacity" of the
* <tt>HashMap</tt> instance (the number of buckets) plus its size (the number of key-value
* mappings). Thus, it's very important not to set the initial capacity too high (or the load factor
* too low) if iteration performance is important.
*
* <p>
* An instance of <tt>HashMap</tt> has two parameters that affect its performance: <i>initial
* capacity</i> and <i>load factor</i>. The <i>capacity</i> is the number of buckets in the hash
* table, and the initial capacity is simply the capacity at the time the hash table is created. The
* <i>load factor</i> is a measure of how full the hash table is allowed to get before its capacity
* is automatically increased. When the number of entries in the hash table exceeds the product of
* the load factor and the current capacity, the hash table is <i>rehashed</i> (that is, internal
* data structures are rebuilt) so that the hash table has approximately twice the number of
* buckets.
*
* <p>
* As a general rule, the default load factor (.75) offers a good tradeoff between time and space
* costs. Higher values decrease the space overhead but increase the lookup cost (reflected in most
* of the operations of the <tt>HashMap</tt> class, including <tt>get</tt> and <tt>put</tt>). The
* expected number of entries in the map and its load factor should be taken into account when
* setting its initial capacity, so as to minimize the number of rehash operations. If the initial
* capacity is greater than the maximum number of entries divided by the load factor, no rehash
* operations will ever occur.
*
* <p>
* If many mappings are to be stored in a <tt>HashMap</tt> instance, creating it with a sufficiently
* large capacity will allow the mappings to be stored more efficiently than letting it perform
* automatic rehashing as needed to grow the table.
*
* <p>
* <strong>Note that this implementation is not synchronized.</strong> If multiple threads access a
* hash map concurrently, and at least one of the threads modifies the map structurally, it
* <i>must</i> be synchronized externally. (A structural modification is any operation that adds or
* deletes one or more mappings; merely changing the value associated with a key that an instance
* already contains is not a structural modification.) This is typically accomplished by
* synchronizing on some object that naturally encapsulates the map.
*
* If no such object exists, the map should be "wrapped" using the
* {@link Collections#synchronizedMap Collections.synchronizedMap} method. This is best done at
* creation time, to prevent accidental unsynchronized access to the map:
*
* <pre>
* Map m = Collections.synchronizedMap(new IntHashMap(...));
* </pre>
*
* <p>
* The iterators returned by all of this class's "collection view methods" are <i>fail-fast</i>: if
* the map is structurally modified at any time after the iterator is created, in any way except
* through the iterator's own <tt>remove</tt> method, the iterator will throw a
* {@link ConcurrentModificationException}. Thus, in the face of concurrent modification, the
* iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at
* an undetermined time in the future.
*
* <p>
* Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally
* speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent
* modification. Fail-fast iterators throw <tt>ConcurrentModificationException</tt> on a best-effort
* basis. Therefore, it would be wrong to write a program that depended on this exception for its
* correctness: <i>the fail-fast behavior of iterators should be used only to detect bugs.</i>
*
* @author Doug Lea
* @author Josh Bloch
* @author Arthur van Hoff
* @author Neal Gafter
*
* @version %I%, %G%
* @see Object#hashCode()
* @see Collection
* @see Map
* @see TreeMap
* @see Hashtable
* @since 1.2
* @since GemFire 7.1
*/
public class ObjectIntHashMap implements Cloneable, Serializable {
private static final long serialVersionUID = 7718697444988416372L;
/**
* 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[] table;
/**
* The number of key-value mappings contained in this map.
*/
transient int size;
/**
* The next size 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 IntHashMap has been structurally modified Structural modifications are
* those that change the number of mappings in the IntHashMap or otherwise modify its internal
* structure (e.g., rehash). This field is used to make iterators on Collection-views of the
* IntHashMap fail-fast. (See ConcurrentModificationException).
*/
transient volatile int modCount;
/**
* Hashing strategy for key objects.
*
*/
final HashingStrategy hashingStrategy; // GemFire addition
/**
* Constructs an empty <tt>HashMap</tt> with the specified initial capacity and load factor.
*
* @param initialCapacity the initial capacity
* @param loadFactor the load factor
* @throws IllegalArgumentException if the initial capacity is negative or the load factor is
* nonpositive
*/
public ObjectIntHashMap(int initialCapacity, float loadFactor, HashingStrategy hs) {
if (initialCapacity < 0)
throw new IllegalArgumentException("Illegal initial capacity: " + initialCapacity);
if (initialCapacity > MAXIMUM_CAPACITY)
initialCapacity = MAXIMUM_CAPACITY;
if (loadFactor <= 0 || Float.isNaN(loadFactor))
throw new IllegalArgumentException("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];
hashingStrategy = (hs == null) ? new IntHashMapStrategy() : hs;
init();
}
public ObjectIntHashMap(int initialCapacity, float loadFactor) {
this(initialCapacity, loadFactor, null);
}
/**
* Constructs an empty <tt>HashMap</tt> with the specified initial capacity and the default load
* factor (0.75).
*
* @param initialCapacity the initial capacity.
* @throws IllegalArgumentException if the initial capacity is negative.
*/
public ObjectIntHashMap(int initialCapacity) {
this(initialCapacity, DEFAULT_LOAD_FACTOR, null);
}
public ObjectIntHashMap(int initialCapacity, HashingStrategy hs) {
this(initialCapacity, DEFAULT_LOAD_FACTOR, hs);
}
public ObjectIntHashMap() {
this(null);
}
/**
* Constructs an empty <tt>HashMap</tt> with the default initial capacity (16) and the default
* load factor (0.75).
*/
public ObjectIntHashMap(HashingStrategy hs) {
this.loadFactor = DEFAULT_LOAD_FACTOR;
threshold = (int) (DEFAULT_INITIAL_CAPACITY * DEFAULT_LOAD_FACTOR);
table = new Entry[DEFAULT_INITIAL_CAPACITY];
this.hashingStrategy = (hs == null) ? new IntHashMapStrategy() : hs;
init();
}
// internal utilities
/**
* Initialization hook for subclasses. This method is called in all constructors and
* pseudo-constructors (clone, readObject) after IntHashMap 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() {}
/**
* Applies a supplemental hash function to a given hashCode, which defends against poor quality
* hash functions. This is critical because IntHashMap uses power-of-two length hash tables, that
* otherwise encounter collisions for hashCodes that do not differ in lower bits. Note: Null keys
* always map to hash 0, thus index 0.
*/
static int hash(int h) {
// This function ensures that hashCodes that differ only by
// constant multiples at each bit position have a bounded
// number of collisions (approximately 8 at default load factor).
h ^= (h >>> 20) ^ (h >>> 12);
return h ^ (h >>> 7) ^ (h >>> 4);
}
/**
* Returns index for hash code h.
*/
static int indexFor(int h, 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
*/
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
*/
public boolean isEmpty() {
return size == 0;
}
/**
* Returns the value to which the specified key is mapped, or {@code null} if this map contains no
* mapping for the key.
*
* <p>
* More formally, if this map contains a mapping from a key {@code k} to a value {@code v} such
* that {@code (key==null ? k==null :
* key.equals(k))}, then this method returns {@code v}; otherwise it returns {@code null}. (There
* can be at most one such mapping.)
*
* <p>
* A return value of {@code null} does not <i>necessarily</i> indicate that the map contains no
* mapping for the key; it's also possible that the map explicitly maps the key to {@code null}.
* The {@link #containsKey containsKey} operation may be used to distinguish these two cases.
*
* @see #put(Object, int)
*/
public int get(Object key) {
if (key == null)
return getForNullKey();
int hash = hash(hashingStrategy.hashCode(key));
for (Entry e = table[indexFor(hash, table.length)]; e != null; e = e.next) {
Object k;
if (e.hash == hash && ((k = e.key) == key || hashingStrategy.equals(k, key)))
return e.value;
}
return 0;
}
/**
* Offloaded version of get() to look up null keys. Null keys map to index 0. This null case is
* split out into separate methods for the sake of performance in the two most commonly used
* operations (get and put), but incorporated with conditionals in others.
*/
private int getForNullKey() {
for (Entry e = table[0]; e != null; e = e.next) {
if (e.key == null)
return e.value;
}
return 0;
}
/**
* 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.
*/
public boolean containsKey(Object key) {
return getEntry(key) != null;
}
/**
* Returns the entry associated with the specified key in the IntHashMap. Returns null if the
* IntHashMap contains no mapping for the key.
*/
final Entry getEntry(Object key) {
int hash = (key == null) ? 0 : hash(hashingStrategy.hashCode(key));
for (Entry e = table[indexFor(hash, table.length)]; e != null; e = e.next) {
Object k;
if (e.hash == hash && ((k = e.key) == key || (key != null && hashingStrategy.equals(k, key))))
return e;
}
return null;
}
/**
* Associates the specified value with the specified key in this map. If the map previously
* contained a mapping for the 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 the previous value associated with <tt>key</tt>, or <tt>null</tt> if there was no
* mapping for <tt>key</tt>. (A <tt>null</tt> return can also indicate that the map
* previously associated <tt>null</tt> with <tt>key</tt>.)
*/
public int put(Object key, int value) {
if (key == null)
return putForNullKey(value);
int hash = hash(hashingStrategy.hashCode(key));
int i = indexFor(hash, table.length);
for (Entry e = table[i]; e != null; e = e.next) {
Object k;
if (e.hash == hash && ((k = e.key) == key || hashingStrategy.equals(k, key))) {
int oldValue = e.value;
e.value = value;
e.recordAccess(this);
return oldValue;
}
}
modCount++;
addEntry(hash, key, value, i);
return 0;
}
/**
* Offloaded version of put for null keys
*/
private int putForNullKey(int value) {
for (Entry e = table[0]; e != null; e = e.next) {
if (e.key == null) {
int oldValue = e.value;
e.value = value;
e.recordAccess(this);
return oldValue;
}
}
modCount++;
addEntry(0, null, value, 0);
return 0;
}
/**
* 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(Object key, int value) {
int hash = (key == null) ? 0 : hash(hashingStrategy.hashCode(key));
int i = indexFor(hash, table.length);
/**
* Look for preexisting entry for key. This will never happen for clone or deserialize. It will
* only happen for construction if the input Map is a sorted map whose ordering is inconsistent
* w/ equals.
*/
for (Entry e = table[i]; e != null; e = e.next) {
Object k;
if (e.hash == hash
&& ((k = e.key) == key || (key != null && hashingStrategy.equals(k, key)))) {
e.value = value;
return;
}
}
createEntry(hash, key, value, i);
}
private void putAllForCreate(ObjectIntHashMap m) {
for (Iterator i = m.entrySet().iterator(); i.hasNext();) {
Entry e = (Entry) i.next();
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.
*
* 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(int newCapacity) {
Entry[] oldTable = table;
int oldCapacity = oldTable.length;
if (oldCapacity == MAXIMUM_CAPACITY) {
threshold = Integer.MAX_VALUE;
return;
}
Entry[] newTable = new Entry[newCapacity];
transfer(newTable);
table = newTable;
threshold = (int) (newCapacity * loadFactor);
}
/**
* Transfers all entries from current table to newTable.
*/
void transfer(Entry[] newTable) {
Entry[] src = table;
int newCapacity = newTable.length;
for (int j = 0; j < src.length; j++) {
Entry e = src[j];
if (e != null) {
src[j] = null;
do {
Entry next = e.next;
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
*/
public void putAll(ObjectIntHashMap m) {
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.size() + size) >= 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 (Iterator i = m.entrySet().iterator(); i.hasNext();) {
Entry e = (Entry) i.next();
put(e.getKey(), e.getValue());
}
}
/**
* Removes the mapping for the specified key from this map if present.
*
* @param key key whose mapping is to be removed from the map
* @return the previous value associated with <tt>key</tt>, or <tt>null</tt> if there was no
* mapping for <tt>key</tt>. (A <tt>null</tt> return can also indicate that the map
* previously associated <tt>null</tt> with <tt>key</tt>.)
*/
public int remove(Object key) {
Entry e = removeEntryForKey(key);
return (e == null ? 0 : e.value);
}
/**
* Removes and returns the entry associated with the specified key in the IntHashMap. Returns null
* if the IntHashMap contains no mapping for this key.
*/
final Entry removeEntryForKey(Object key) {
int hash = (key == null) ? 0 : hash(hashingStrategy.hashCode(key));
int i = indexFor(hash, table.length);
Entry prev = table[i];
Entry e = prev;
while (e != null) {
Entry next = e.next;
Object k;
if (e.hash == hash
&& ((k = e.key) == key || (key != null && hashingStrategy.equals(k, 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.
*/
final Entry removeMapping(Object o) {
if (!(o instanceof Entry))
return null;
Entry entry = (Entry) o;
Object key = entry.getKey();
int hash = (key == null) ? 0 : hash(hashingStrategy.hashCode(key));
int i = indexFor(hash, table.length);
Entry prev = table[i];
Entry e = prev;
while (e != null) {
Entry 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 of the mappings from this map. The map will be empty after this call returns.
*/
public void clear() {
modCount++;
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
*/
public boolean containsValue(int value) {
Entry[] tab = table;
for (int i = 0; i < tab.length; i++)
for (Entry e = tab[i]; e != null; e = e.next)
if (value == e.value)
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
*/
public Object clone() {
ObjectIntHashMap result = null;
try {
result = (ObjectIntHashMap) super.clone();
} catch (CloneNotSupportedException e) {
// assert false;
}
result.table = new Entry[table.length];
result.entrySet = null;
result.modCount = 0;
result.size = 0;
result.init();
result.putAllForCreate(this);
return result;
}
// Comparison and hashing.
/**
* Compares the specified object with this map for equality. Returns <tt>true</tt> if the given
* object is also a map and the two maps represent the same mappings. More formally, two maps
* <tt>m1</tt> and <tt>m2</tt> represent the same mappings if
* <tt>m1.entrySet().equals(m2.entrySet())</tt>. This ensures that the <tt>equals</tt> method
* works properly across different implementations of the <tt>Map</tt> interface.
*
* <p>
* This implementation first checks if the specified object is this map; if so it returns
* <tt>true</tt>. Then, it checks if the specified object is a map whose size is identical to the
* size of this map; if not, it returns <tt>false</tt>. If so, it iterates over this map's
* <tt>entrySet</tt> collection, and checks that the specified map contains each mapping that this
* map contains. If the specified map fails to contain such a mapping, <tt>false</tt> is returned.
* If the iteration completes, <tt>true</tt> is returned.
*
* @param o object to be compared for equality with this map
* @return <tt>true</tt> if the specified object is equal to this map
*/
public boolean equals(Object o) {
if (o == this)
return true;
if (!(o instanceof ObjectIntHashMap))
return false;
ObjectIntHashMap m = (ObjectIntHashMap) o;
if (m.size() != size())
return false;
try {
Iterator<Entry> i = entrySet().iterator();
while (i.hasNext()) {
Entry e = i.next();
Object key = e.getKey();
int value = e.getValue();
if (!(m.containsKey(key))) {
return false;
} else if (!(value == m.get(key))) {
return false;
}
}
} catch (ClassCastException unused) {
return false;
} catch (NullPointerException unused) {
return false;
}
return true;
}
/**
* Returns the hash code value for this map. The hash code of a map is defined to be the sum of
* the hash codes of each entry in the map's <tt>entrySet()</tt> view. This ensures that
* <tt>m1.equals(m2)</tt> implies that <tt>m1.hashCode()==m2.hashCode()</tt> for any two maps
* <tt>m1</tt> and <tt>m2</tt>, as required by the general contract of {@link Object#hashCode}.
*
* <p>
* This implementation iterates over <tt>entrySet()</tt>, calling
* {@link java.util.Map.Entry#hashCode() hashCode()} on each element (entry) in the set, and
* adding up the results.
*
* @return the hash code value for this map
* @see java.util.Map.Entry#hashCode()
* @see Object#equals(Object)
* @see Set#equals(Object)
*/
public int hashCode() {
int h = 0;
Iterator<Entry> i = entrySet().iterator();
while (i.hasNext())
h += i.next().hashCode();
return h;
}
/**
* Returns a string representation of this map. The string representation consists of a list of
* key-value mappings in the order returned by the map's <tt>entrySet</tt> view's iterator,
* enclosed in braces (<tt>"{}"</tt>). Adjacent mappings are separated by the characters
* <tt>", "</tt> (comma and space). Each key-value mapping is rendered as the key followed by an
* equals sign (<tt>"="</tt>) followed by the associated value. Keys and values are converted to
* strings as by {@link String#valueOf(Object)}.
*
* @return a string representation of this map
*/
public String toString() {
Iterator<Entry> i = entrySet().iterator();
if (!i.hasNext())
return "{}";
StringBuilder sb = new StringBuilder();
sb.append('{');
for (;;) {
Entry e = i.next();
Object key = e.getKey();
int value = e.getValue();
sb.append(key == this ? "(this Map)" : key);
sb.append('=');
sb.append(value);
if (!i.hasNext())
return sb.append('}').toString();
sb.append(", ");
}
}
class Entry {
final Object key;
int value; // GemFire Addition.
Entry next;
final int hash;
/**
* Creates new entry.
*/
Entry(int h, Object k, int v, Entry n) {
value = v;
next = n;
key = k;
hash = h;
}
public final Object getKey() {
return key;
}
public final int getValue() {
return value;
}
public final int setValue(int newValue) {
int oldValue = value;
value = newValue;
return oldValue;
}
public final boolean equals(Object o) {
if (!(o instanceof Entry))
return false;
Entry e = (Entry) o;
Object k1 = getKey();
Object k2 = e.getKey();
if (k1 == k2 || (k1 != null && hashingStrategy.equals(k1, k2))) {
int v1 = getValue();
int v2 = e.getValue();
if (v1 == v2)
return true;
}
return false;
}
public final int hashCode() {
return this.hash ^ value;
}
public final 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 IntHashMap.
*/
void recordAccess(ObjectIntHashMap m) {}
/**
* This method is invoked whenever the entry is removed from the table.
*/
void recordRemoval(ObjectIntHashMap m) {}
}
/**
* Adds 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.
*
* Subclass overrides this to alter the behavior of put method.
*/
void addEntry(int hash, Object key, int value, int bucketIndex) {
Entry e = table[bucketIndex];
table[bucketIndex] = new Entry(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.
*
* Subclass overrides this to alter the behavior of IntHashMap(Map), clone, and readObject.
*/
void createEntry(int hash, Object key, int value, int bucketIndex) {
Entry e = table[bucketIndex];
table[bucketIndex] = new Entry(hash, key, value, e);
size++;
}
private abstract class HashIterator<E> implements Iterator<E> {
Entry next; // next entry to return
int expectedModCount; // For fast-fail
int index; // current slot
Entry current; // current entry
HashIterator() {
expectedModCount = modCount;
if (size > 0) { // advance to first entry
Entry[] t = table;
while (index < t.length && (next = t[index++]) == null);
}
}
public final boolean hasNext() {
return next != null;
}
final Entry nextEntry() {
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
Entry e = next;
if (e == null)
throw new NoSuchElementException();
if ((next = e.next) == null) {
Entry[] t = table;
while (index < t.length && (next = t[index++]) == null);
}
current = e;
return e;
}
public void remove() {
if (current == null)
throw new IllegalStateException();
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
Object k = current.key;
current = null;
ObjectIntHashMap.this.removeEntryForKey(k);
expectedModCount = modCount;
}
}
private final class KeyIterator extends HashIterator<Object> {
public Object next() {
return nextEntry().getKey();
}
}
private final class EntryIterator extends HashIterator<Entry> {
public Entry next() {
return nextEntry();
}
}
// Subclass overrides these to alter behavior of views' iterator() method
Iterator<Object> newKeyIterator() {
return new KeyIterator();
}
Iterator<Entry> newEntryIterator() {
return new EntryIterator();
}
// Views
private transient Set<Entry> entrySet = null;
private transient Set<Object> keySet = null;
/**
* Returns a {@link Set} view of the keys contained in this map. The set is backed by the map, so
* changes to the map are reflected in the set, and vice-versa. If the map is modified while an
* iteration over the set is in progress (except through the iterator's own <tt>remove</tt>
* operation), the results of the iteration are undefined. The set supports element removal, which
* removes the corresponding mapping from the map, via the <tt>Iterator.remove</tt>,
* <tt>Set.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.
*/
public Set<Object> keySet() {
Set<Object> ks = keySet;
return (ks != null ? ks : (keySet = new KeySet()));
}
private final class KeySet extends AbstractSet<Object> {
public Iterator<Object> iterator() {
return newKeyIterator();
}
public int size() {
return size;
}
public boolean contains(Object o) {
return containsKey(o);
}
public boolean remove(Object o) {
return ObjectIntHashMap.this.removeEntryForKey(o) != null;
}
public void clear() {
ObjectIntHashMap.this.clear();
}
}
/**
* Returns a {@link Set} view of the mappings contained in this map. The set is backed by the map,
* so changes to the map are reflected in the set, and vice-versa. If the map is modified while an
* iteration over the set is in progress (except through the iterator's own <tt>remove</tt>
* operation, or through the <tt>setValue</tt> operation on a map entry returned by the iterator)
* the results of the iteration are undefined. The set supports element removal, which removes the
* corresponding mapping from the map, via the <tt>Iterator.remove</tt>, <tt>Set.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 set view of the mappings contained in this map
*/
public Set<Entry> entrySet() {
return entrySet0();
}
private Set<Entry> entrySet0() {
Set<Entry> es = entrySet;
return es != null ? es : (entrySet = new EntrySet());
}
private final class EntrySet extends AbstractSet<Entry> {
public Iterator<Entry> iterator() {
return newEntryIterator();
}
public boolean contains(Object o) {
if (!(o instanceof Entry))
return false;
Entry e = (Entry) o;
Entry candidate = getEntry(e.getKey());
return candidate != null && candidate.equals(e);
}
public boolean remove(Object o) {
return removeMapping(o) != null;
}
public int size() {
return size;
}
public void clear() {
ObjectIntHashMap.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 IntHashMap (the length of the bucket array) is emitted
* (int), followed by the <i>size</i> (an int, the number of key-value mappings),
* followed by the key (Object) and value (Object) for each key-value mapping. The
* key-value mappings are emitted in no particular order.
*/
private void writeObject(java.io.ObjectOutputStream s) throws IOException {
Iterator<Entry> i = (size > 0) ? entrySet0().iterator() : null;
// Write out the threshold, loadfactor, and any hidden stuff
s.defaultWriteObject();
// Write out number of buckets
s.writeInt(table.length);
// Write out size (number of Mappings)
s.writeInt(size);
// Write out keys and values (alternating)
if (i != null) {
while (i.hasNext()) {
Entry e = i.next();
s.writeObject(e.getKey());
s.writeInt(e.getValue());
}
}
}
/**
* Reconstitute the <tt>HashMap</tt> instance from a stream (i.e., deserialize it).
*/
private void readObject(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;
int numBuckets = s.readInt();
table = new Entry[numBuckets];
init(); // Give subclass a chance to do its thing.
// Read in size (number of Mappings)
int size = s.readInt();
// Read the keys and values, and put the mappings in the IntHashMap
for (int i = 0; i < size; i++) {
Object key = (Object) s.readObject();
int value = (int) s.readInt();
putForCreate(key, value);
}
}
// These methods are used when serializing HashSets
int capacity() {
return table.length;
}
float loadFactor() {
return loadFactor;
}
private final class IntHashMapStrategy implements HashingStrategy {
@Override
public int hashCode(Object o) {
return o.hashCode();
}
@Override
public boolean equals(Object o1, Object o2) {
if (o1 == null && o2 == null)
return true;
if (o1 == null || o2 == null)
return false;
return o1.equals(o2);
}
}
}