package java.util;
/*
* %W% %E%
*
* Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
//import java.io.*;
import javax.safetycritical.ManagedMemory;
//import scjlibs.lang.Cloneable;
/**
* Hash table based implementation of the <tt>Map</tt> interface. This
* implementation provides all of the optional map operations, and permits
* <tt>null</tt> values and the <tt>null</tt> key. (The <tt>HashMap</tt>
* class is roughly equivalent to <tt>Hashtable</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 HashMap(...));</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>
*
* <p>This class is a member of the
* <a href="{@docRoot}/../technotes/guides/collections/index.html">
* Java Collections Framework</a>.
*
* @param <K> the type of keys maintained by this map
* @param <V> the type of mapped values
*
* @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
*/
public class HashMap<K,V>
extends AbstractMap<K,V>
implements Map<K,V> //, Cloneable //, Serializable
{
/**
* 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.
*/
public transient Entry<K,V>[] 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 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;
/**
* 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 HashMap(int initialCapacity, float loadFactor) {
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];
init();
}
/**
* 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 HashMap(int initialCapacity) {
this(initialCapacity, DEFAULT_LOAD_FACTOR);
}
/**
* Constructs an empty <tt>HashMap</tt> with the default initial capacity
* (16) and the default load factor (0.75).
*/
public HashMap() {
this.loadFactor = DEFAULT_LOAD_FACTOR;
threshold = (int)(DEFAULT_INITIAL_CAPACITY * DEFAULT_LOAD_FACTOR);
table = new Entry[DEFAULT_INITIAL_CAPACITY];
init();
}
//TODO: Review this constructor
/**
* 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
* @throws NullPointerException if the specified map is null
*/
public HashMap(Map<? extends K, ? extends V> m) {
this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
DEFAULT_INITIAL_CAPACITY), DEFAULT_LOAD_FACTOR);
putAllForCreate(m);
}
// internal utilities
/**
* Initialization hook for subclasses. This method is called
* in all constructors and 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.)
*/
Entry<K,V>[] freeEntries;
void init() {
// Initialize Entry pool
freeEntries = new Entry[table.length];
for(int i=0; i<table.length; i++){
freeEntries[i] = new Entry<K, V>();
}
// Initialize the views of the HashMap
entrySet = new EntrySet();
keySet = new KeySet();
values = new Values();
}
/**
* Applies a supplemental hash function to a given hashCode, which
* defends against poor quality hash functions. This is critical
* because HashMap 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.
*/
@MemSafe(risk = {MemoryRisk.NONE})
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.
*/
@MemSafe(risk = {MemoryRisk.NONE})
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
*/
@MemSafe(risk = {MemoryRisk.NONE})
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
*/
@MemSafe(risk = {MemoryRisk.NONE})
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, Object)
*/
@MemSafe(risk ={MemoryRisk.NONE})
public V get(Object key) {
if (key == null)
return getForNullKey();
int hash = hash(key.hashCode());
// System.out.println("get: "+indexFor(hash, table.length));
//
// if(table[indexFor(hash, table.length)] == null){
// System.out.println("null");
// }else{
// System.out.println("Not null");
// }
for (Entry<K, V> e = table[indexFor(hash, table.length)]; e != null; e = e.next) {
Object k;
if (e.hash == hash && ((k = e.key) == key || key.equals(k)))
return e.value;
}
return null;
}
/**
* 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.
*/
@MemSafe(risk ={MemoryRisk.NONE})
private V getForNullKey() {
// System.out.println("uh?");
for (Entry<K,V> e = table[0]; e != null; e = e.next) {
if (e.key == null)
return e.value;
}
return null;
}
/**
* 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.
*/
@MemSafe(risk ={MemoryRisk.NONE})
public boolean containsKey(Object key) {
return getEntry(key) != null;
}
/**
* Returns the entry associated with the specified key in the
* HashMap. Returns null if the HashMap contains no mapping
* for the key.
*/
@MemSafe(risk ={MemoryRisk.NONE})
final Entry<K, V> getEntry(Object key) {
int hash = (key == null) ? 0 : hash(key.hashCode());
for (Entry<K, V> e = table[indexFor(hash, table.length)]; e != null; e = e.next) {
Object k;
if (e.hash == hash
&& ((k = e.key) == key || (key != null && key.equals(k))))
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>.)
*/
@MemSafe(risk = {MemoryRisk.MIXED_CONTEXT, MemoryRisk.UNREFERENCED_OBJ})
public V put(K key, V value) {
if (key == null)
return putForNullKey(value);
int hash = hash(key.hashCode());
int i = indexFor(hash, table.length);
// System.out.println("put: "+indexFor(hash, table.length));
for (Entry<K,V> e = table[i]; e != null; e = e.next) {
Object k;
if (e.hash == hash && ((k = e.key) == key || key.equals(k))) {
V oldValue = e.value;
e.value = value;
e.recordAccess(this);
return oldValue;
}
}
modCount++;
addEntry(hash, key, value, i);
return null;
}
/**
* Offloaded version of put for null keys
*/
@MemSafe(risk = {MemoryRisk.UNREFERENCED_OBJ})
private V putForNullKey(V value) {
for (Entry<K,V> e = table[0]; e != null; e = e.next) {
if (e.key == null) {
V oldValue = e.value;
e.value = value;
e.recordAccess(this);
return oldValue;
}
}
modCount++;
addEntry(0, null, value, 0);
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.
*/
@MemSafe(risk = {MemoryRisk.MIXED_CONTEXT, MemoryRisk.UNREFERENCED_OBJ})
private void putForCreate(K key, V value) {
int hash = (key == null) ? 0 : hash(key.hashCode());
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<K,V> e = table[i]; e != null; e = e.next) {
Object k;
if (e.hash == hash &&
((k = e.key) == key || (key != null && key.equals(k)))) {
e.value = value;
return;
}
}
//XXX
// createEntry(hash, key, value, i);
}
@MemSafe(risk = {MemoryRisk.MIXED_CONTEXT, MemoryRisk.UNREFERENCED_OBJ})
private void putAllForCreate(Map<? extends K, ? extends V> m) {
for (Iterator<? extends Map.Entry<? extends K, ? extends V>> i = m.entrySet().iterator(); i.hasNext(); ) {
Map.Entry<? extends K, ? extends V> e = 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).
// */
// @MemSafe(risk = {MemoryRisk.UNREFERENCED_OBJ, MemoryRisk.MIXED_CONTEXT})
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.
// */
// @MemSafe(risk = {MemoryRisk.MIXED_CONTEXT})
// void transfer(Entry[] newTable) {
// Entry[] src = table;
// 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 {
// Entry<K,V> 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
// */
// @MemSafe(risk = {MemoryRisk.UNREFERENCED_OBJ, MemoryRisk.MIXED_CONTEXT, MemoryRisk.TEMP_OBJECTS})
// public void putAll(Map<? extends K, ? extends V> 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)
// //XXX
//// resize(newCapacity);
// }
//
// for (Iterator<? extends Map.Entry<? extends K, ? extends V>> i = m.entrySet().iterator(); i.hasNext(); ) {
// Map.Entry<? extends K, ? extends V> e = 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>.)
*/
@MemSafe(risk = {MemoryRisk.UNREFERENCED_OBJ})
public V remove(Object key) {
Entry<K, V> e = removeEntryForKey(key);
V tempValue;
if (e == null) {
return null;
} else {
tempValue = e.value;
/* Return the entry to the entry pool */
e.isFree = true;
e.hash = 0;
/*
* Key and Value objects should also be returned
* to their respective pools
*/
e.key = null;
e.value = null;
e.next = null;
return tempValue;
}
// 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.
*/
@MemSafe(risk = {MemoryRisk.UNREFERENCED_OBJ})
final Entry<K, V> removeEntryForKey(Object key) {
int hash = (key == null) ? 0 : hash(key.hashCode());
int i = indexFor(hash, table.length);
Entry<K, V> prev = table[i];
Entry<K, V> e = prev;
while (e != null) {
Entry<K, V> next = e.next;
Object k;
if (e.hash == hash
&& ((k = e.key) == key || (key != null && key.equals(k)))) {
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<K,V> removeMapping(Object o) {
if (!(o instanceof Map.Entry))
return null;
Map.Entry<K,V> entry = (Map.Entry<K,V>) o;
Object key = entry.getKey();
int hash = (key == null) ? 0 : hash(key.hashCode());
int i = indexFor(hash, table.length);
Entry<K,V> prev = table[i];
Entry<K,V> e = prev;
while (e != null) {
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 of the mappings from this map.
* The map will be empty after this call returns.
*/
@MemSafe(risk = {MemoryRisk.OBJ_REF_TO_NULL})
public void clear() {
modCount++;
// Entry[] tab = table;
// for (int i = 0; i < tab.length; i++){
for (int i = 0; i < table.length; i++){
// tab[i] = null;
// Entry<K,V> e = tab[i];
Entry<K,V> e = table[i];
while(e != null){
Entry<K,V> next = e.next;
e.clear();
e = next;
}
}
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
*/
@MemSafe(risk = {MemoryRisk.NONE})
public boolean containsValue(Object value) {
if (value == null)
return containsNullValue();
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
*/
@MemSafe(risk = {MemoryRisk.NONE})
private boolean containsNullValue() {
Entry[] tab = table;
for (int i = 0; i < tab.length ; i++)
for (Entry e = tab[i] ; 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
// */
// public Object clone() {
// HashMap<K, V> result = null;
// try {
// result = (HashMap<K, V>) 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;
// }
static class Entry<K,V > implements Map.Entry<K,V> {
// final K key;
K key;
V value;
Entry<K,V> next;
// final int hash;
int hash;
public boolean isFree = true;
/**
* Creates new entry.
*/
Entry(int h, K k, V v, Entry<K,V> n) {
value = v;
next = n;
key = k;
hash = h;
isFree = true;
}
Entry(){
value = null;
next = null;
key = null;
hash = 0;
isFree = true;
}
public final K getKey() {
return key;
}
public final V getValue() {
return value;
}
@MemSafe(risk = {MemoryRisk.UNREFERENCED_OBJ})
public final V setValue(V newValue) {
V oldValue = value;
value = newValue;
return oldValue;
}
public final boolean equals(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry e = (Map.Entry)o;
Object k1 = getKey();
Object k2 = e.getKey();
if (k1 == k2 || (k1 != null && k1.equals(k2))) {
Object v1 = getValue();
Object v2 = e.getValue();
if (v1 == v2 || (v1 != null && v1.equals(v2)))
return true;
}
return false;
}
public final int hashCode() {
return (key==null ? 0 : key.hashCode()) ^
(value==null ? 0 : value.hashCode());
}
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 HashMap.
*/
void recordAccess(HashMap<K,V> m) {
}
/**
* This method is invoked whenever the entry is
* removed from the table.
*/
void recordRemoval(HashMap<K,V> m) {
}
void clear(){
value = null;
next = null;
key = null;
hash = 0;
isFree = true;
}
}
/**
* 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.
*/
@MemSafe(risk = { MemoryRisk.MIXED_CONTEXT, MemoryRisk.RESIZE })
void addEntry(int hash, K key, V value, int bucketIndex) {
Entry<K, V> e = table[bucketIndex];
// table[bucketIndex] = new Entry<K,V>(hash, key, value, e);
if (size < freeEntries.length) {
for (int i = 0; i < freeEntries.length; i++) {
if (freeEntries[i].isFree) {
table[bucketIndex] = freeEntries[i];
// System.out.println("Found free entry");
break;
}
}
table[bucketIndex].hash = hash;
table[bucketIndex].key = key;
table[bucketIndex].value = value;
table[bucketIndex].isFree = false;
table[bucketIndex].next = e;
/* Increase size only if we find a free entry */
size++;
} else {
System.out.println("Can't add entry");
}
// table[bucketIndex] = getFreeEntry(hash, key, value, e);
// if(table[bucketIndex]==null){
// System.out.println("hu?");
// }
// Resize operation not allowed for scope safety.
// if (size++ >= threshold)
// resize(2 * table.length);
}
// private Entry<K, V> getFreeEntry(int hash, K key, V value, Entry<K, V> next) {
//
// Entry<K, V> e = null;
//
// if (size < freeEntries.length) {
// for (int i = 0; i < freeEntries.length; i++) {
// if (freeEntries[i].isFree) {
// e = freeEntries[i];
// System.out.println("Not null");
// break;
// }
// }
// e.hash = hash;
// e.key = key;
// e.value = value;
// e.isFree = false;
// e.next = next;
//
// /* Increase size only if we find a free entry */
// size++;
// return e;
// } else {
// System.out.println("Can't add entry");
// return null;
// }
//
//// return e;
// }
// /**
// * 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 HashMap(Map),
// * clone, and readObject.
// */
// @MemSafe(risk = {MemoryRisk.MIXED_CONTEXT})
// void createEntry(int hash, K key, V value, int bucketIndex) {
// 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;
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<K, V> nextEntry() {
if (modCount != expectedModCount){
throw new ConcurrentModificationException();
}
Entry<K, V> 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;
HashMap.this.removeEntryForKey(k);
expectedModCount = modCount;
}
}
private final class ValueIterator extends HashIterator<V> {
public V next() {
return nextEntry().value;
}
}
private final class KeyIterator extends HashIterator<K> {
public K next() {
return nextEntry().getKey();
}
}
private final class EntryIterator extends HashIterator<Map.Entry<K,V>> {
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 {@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.
*/
@MemSafe(risk = {MemoryRisk.LAZY})
public Set<K> keySet() {
return keySet;
// Set<K> ks = keySet;
//
// if(ks!=null){
// return ks;
// }else{
// ManagedMemory.executeInAreaOf(table, new Runnable() {
//
// @Override
// public void run() {
// // TODO Auto-generated method stub
// keySet = new KeySet();
//
// }
// });
// return keySet;
// }
// return (ks != null ? ks : (keySet = new KeySet()));
}
private final class KeySet extends AbstractSet<K> {
public Iterator<K> iterator() {
return newKeyIterator();
}
public int size() {
return size;
}
public boolean contains(Object o) {
return containsKey(o);
}
public boolean remove(Object o) {
Entry<K,V> e = HashMap.this.removeEntryForKey(o);
if (e == null) {
return false;
} else {
/* Return the entry to the entry pool */
e.isFree = true;
e.hash = 0;
/*
* Key and Value objects should also be returned
* to their respective pools
*/
e.key = null;
e.value = null;
e.next = null;
return true;
}
// return HashMap.this.removeEntryForKey(o) != null;
}
public void clear() {
HashMap.this.clear();
}
}
/**
* Returns a {@link Collection} view of the values contained in this map.
* The collection is backed by the map, so changes to the map are
* reflected in the collection, and vice-versa. If the map is
* modified while an iteration over the collection is in progress
* (except through the iterator's own <tt>remove</tt> operation),
* the results of the iteration are undefined. 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.
*/
@MemSafe(risk = {MemoryRisk.LAZY})
public Collection<V> values() {
return values;
// Collection<V> vs = values;
// return (vs != null ? vs : (values = new Values()));
}
private final class Values extends AbstractCollection<V> {
public Iterator<V> iterator() {
return newValueIterator();
}
public int size() {
return size;
}
public boolean contains(Object o) {
return containsValue(o);
}
public void clear() {
HashMap.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
*/
@MemSafe(risk = {MemoryRisk.LAZY})
public Set<Map.Entry<K, V>> entrySet() {
return entrySet;
// return entrySet0();
}
// @MemSafe(risk = {MemoryRisk.LAZY})
// private Set<Map.Entry<K, V>> entrySet0() {
// Set<Map.Entry<K, V>> es = entrySet;
// if (es != null) {
// return es;
// } else {
// ManagedMemory.executeInAreaOf(this, new Runnable() {
// @Override
// public void run() {
// // TODO Auto-generated method stub
// entrySet = new EntrySet();
// }
// });
// return entrySet;
// }
//
//// return es != null ? es : (entrySet = new EntrySet());
// }
private final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
public Iterator<Map.Entry<K,V>> iterator() {
return newEntryIterator();
}
public boolean contains(Object o) {
if (!(o instanceof Map.Entry))
return false;
Map.Entry<K,V> e = (Map.Entry<K,V>) o;
Entry<K,V> 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() {
HashMap.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>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<Map.Entry<K,V>> 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()) {
// Map.Entry<K,V> e = i.next();
// s.writeObject(e.getKey());
// s.writeObject(e.getValue());
// }
// }
// }
// private static final long serialVersionUID = 362498820763181265L;
//
// /**
// * 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 HashMap
// for (int i=0; i<size; i++) {
// K key = (K) s.readObject();
// V value = (V) s.readObject();
// putForCreate(key, value);
// }
// }
// These methods are used when serializing HashSets
public int capacity() { return table.length; }
// float loadFactor() { return loadFactor; }
}