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/* Generic definitions */
/* Assertions (useful to generate conditional code) */
/* Current type and class (and size, if applicable) */
/* Value methods */
/* Interfaces (keys) */
/* Interfaces (values) */
/* Abstract implementations (keys) */
/* Abstract implementations (values) */
/* Static containers (keys) */
/* Static containers (values) */
/* Implementations */
/* Synchronized wrappers */
/* Unmodifiable wrappers */
/* Other wrappers */
/* Methods (keys) */
/* Methods (values) */
/* Methods (keys/values) */
/* Methods that have special names depending on keys (but the special names depend on values) */
/* Equality */
/* Object/Reference-only definitions (keys) */
/* Object/Reference-only definitions (values) */
/*
* Copyright (C) 2002-2015 Sebastiano Vigna
*
* Licensed 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 it.unimi.dsi.fastutil.objects;
import it.unimi.dsi.fastutil.Hash;
import it.unimi.dsi.fastutil.HashCommon;
import static it.unimi.dsi.fastutil.HashCommon.arraySize;
import static it.unimi.dsi.fastutil.HashCommon.maxFill;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Comparator;
/** A type-specific linked hash set with with a fast, small-footprint implementation.
*
* Instances of this class use a hash table to represent a set. The table is filled up to a specified load factor, and then doubled in size to accommodate new entries. If the table is
* emptied below one fourth of the load factor, it is halved in size. However, halving is not performed when deleting entries from an iterator, as it would interfere with the iteration
* process.
*
*
Note that {@link #clear()} does not modify the hash table size. Rather, a family of {@linkplain #trim() trimming methods} lets you control the size of the table; this is particularly useful if
* you reuse instances of this class.
*
*
Iterators generated by this set will enumerate elements in the same order in which they have been added to the set (addition of elements already present in the set does not change the iteration
* order). Note that this order has nothing in common with the natural order of the keys. The order is kept by means of a doubly linked list, represented via an array of longs parallel to the
* table.
*
*
This class implements the interface of a sorted set, so to allow easy access of the iteration order: for instance, you can get the first element in iteration order with {@link #first()} without
* having to create an iterator; however, this class partially violates the {@link java.util.SortedSet} contract because all subset methods throw an exception and {@link #comparator()} returns always
* null.
*
*
Additional methods, such as addAndMoveToFirst(), make it easy to use instances of this class as a cache (e.g., with LRU policy).
*
*
The iterators provided by this class are type-specific {@linkplain java.util.ListIterator list iterators}, and can be started at any element which is in the set (if the provided element
* is not in the set, a {@link NoSuchElementException} exception will be thrown). If, however, the provided element is not the first or last element in the set, the first access to the list index will
* require linear time, as in the worst case the entire set must be scanned in iteration order to retrieve the positional index of the starting element. If you use just the methods of a type-specific
* {@link it.unimi.dsi.fastutil.BidirectionalIterator}, however, all operations will be performed in constant time.
*
* @see Hash
* @see HashCommon */
public class ReferenceLinkedOpenHashSet extends AbstractReferenceSortedSet implements java.io.Serializable, Cloneable, Hash {
private static final long serialVersionUID = 0L;
private static final boolean ASSERTS = false;
/** The array of keys. */
protected transient K[] key;
/** The mask for wrapping a position counter. */
protected transient int mask;
/** Whether this set contains the null key. */
protected transient boolean containsNull;
/** The index of the first entry in iteration order. It is valid iff {@link #size} is nonzero; otherwise, it contains -1. */
protected transient int first = -1;
/** The index of the last entry in iteration order. It is valid iff {@link #size} is nonzero; otherwise, it contains -1. */
protected transient int last = -1;
/** For each entry, the next and the previous entry in iteration order, stored as ((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL). The first entry contains predecessor -1, and the
* last entry contains successor -1. */
protected transient long[] link;
/** The current table size. */
protected transient int n;
/** Threshold after which we rehash. It must be the table size times {@link #f}. */
protected transient int maxFill;
/** Number of entries in the set (including the null key, if present). */
protected int size;
/** The acceptable load factor. */
protected final float f;
/** Creates a new hash set.
*
* The actual table size will be the least power of two greater than expected/f.
*
* @param expected the expected number of elements in the hash set.
* @param f the load factor. */
@SuppressWarnings("unchecked")
public ReferenceLinkedOpenHashSet( final int expected, final float f ) {
if ( f <= 0 || f > 1 ) throw new IllegalArgumentException( "Load factor must be greater than 0 and smaller than or equal to 1" );
if ( expected < 0 ) throw new IllegalArgumentException( "The expected number of elements must be nonnegative" );
this.f = f;
n = arraySize( expected, f );
mask = n - 1;
maxFill = maxFill( n, f );
key = (K[])new Object[ n + 1 ];
link = new long[ n + 1 ];
}
/** Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor.
*
* @param expected the expected number of elements in the hash set. */
public ReferenceLinkedOpenHashSet( final int expected ) {
this( expected, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash set with initial expected {@link Hash#DEFAULT_INITIAL_SIZE} elements and {@link Hash#DEFAULT_LOAD_FACTOR} as load factor. */
public ReferenceLinkedOpenHashSet() {
this( DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash set copying a given collection.
*
* @param c a {@link Collection} to be copied into the new hash set.
* @param f the load factor. */
public ReferenceLinkedOpenHashSet( final Collection c, final float f ) {
this( c.size(), f );
addAll( c );
}
/** Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor copying a given collection.
*
* @param c a {@link Collection} to be copied into the new hash set. */
public ReferenceLinkedOpenHashSet( final Collection c ) {
this( c, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash set copying a given type-specific collection.
*
* @param c a type-specific collection to be copied into the new hash set.
* @param f the load factor. */
public ReferenceLinkedOpenHashSet( final ReferenceCollection c, final float f ) {
this( c.size(), f );
addAll( c );
}
/** Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor copying a given type-specific collection.
*
* @param c a type-specific collection to be copied into the new hash set. */
public ReferenceLinkedOpenHashSet( final ReferenceCollection c ) {
this( c, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash set using elements provided by a type-specific iterator.
*
* @param i a type-specific iterator whose elements will fill the set.
* @param f the load factor. */
public ReferenceLinkedOpenHashSet( final Iterator i, final float f ) {
this( DEFAULT_INITIAL_SIZE, f );
while ( i.hasNext() )
add( i.next() );
}
/** Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor using elements provided by a type-specific iterator.
*
* @param i a type-specific iterator whose elements will fill the set. */
public ReferenceLinkedOpenHashSet( final Iterator i ) {
this( i, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash set and fills it with the elements of a given array.
*
* @param a an array whose elements will be used to fill the set.
* @param offset the first element to use.
* @param length the number of elements to use.
* @param f the load factor. */
public ReferenceLinkedOpenHashSet( final K[] a, final int offset, final int length, final float f ) {
this( length < 0 ? 0 : length, f );
ObjectArrays.ensureOffsetLength( a, offset, length );
for ( int i = 0; i < length; i++ )
add( a[ offset + i ] );
}
/** Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor and fills it with the elements of a given array.
*
* @param a an array whose elements will be used to fill the set.
* @param offset the first element to use.
* @param length the number of elements to use. */
public ReferenceLinkedOpenHashSet( final K[] a, final int offset, final int length ) {
this( a, offset, length, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash set copying the elements of an array.
*
* @param a an array to be copied into the new hash set.
* @param f the load factor. */
public ReferenceLinkedOpenHashSet( final K[] a, final float f ) {
this( a, 0, a.length, f );
}
/** Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor copying the elements of an array.
*
* @param a an array to be copied into the new hash set. */
public ReferenceLinkedOpenHashSet( final K[] a ) {
this( a, DEFAULT_LOAD_FACTOR );
}
private int realSize() {
return containsNull ? size - 1 : size;
}
private void ensureCapacity( final int capacity ) {
final int needed = arraySize( capacity, f );
if ( needed > n ) rehash( needed );
}
private void tryCapacity( final long capacity ) {
final int needed = (int)Math.min( 1 << 30, Math.max( 2, HashCommon.nextPowerOfTwo( (long)Math.ceil( capacity / f ) ) ) );
if ( needed > n ) rehash( needed );
}
/** {@inheritDoc} */
public boolean addAll( Collection c ) {
// The resulting collection will be at least c.size() big
if ( f <= .5 ) ensureCapacity( c.size() ); // The resulting collection will be sized for c.size() elements
else tryCapacity( size() + c.size() ); // The resulting collection will be tentatively sized for size() + c.size() elements
return super.addAll( c );
}
public boolean add( final K k ) {
int pos;
if ( ( ( k ) == ( null ) ) ) {
if ( containsNull ) return false;
pos = n;
containsNull = true;
}
else {
K curr;
final K[] key = this.key;
// The starting point.
if ( !( ( curr = key[ pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( k ) ) ) & mask ] ) == ( null ) ) ) {
if ( ( ( curr ) == ( k ) ) ) return false;
while ( !( ( curr = key[ pos = ( pos + 1 ) & mask ] ) == ( null ) ) )
if ( ( ( curr ) == ( k ) ) ) return false;
}
key[ pos ] = k;
}
if ( size == 0 ) {
first = last = pos;
// Special case of SET_UPPER_LOWER(link[ pos ], -1, -1);
link[ pos ] = -1L;
}
else {
link[ last ] ^= ( ( link[ last ] ^ ( pos & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ pos ] = ( ( last & 0xFFFFFFFFL ) << 32 ) | ( -1 & 0xFFFFFFFFL );
last = pos;
}
if ( size++ >= maxFill ) rehash( arraySize( size + 1, f ) );
if ( ASSERTS ) checkTable();
return true;
}
/** Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.
*
* @param pos a starting position. */
protected final void shiftKeys( int pos ) {
// Shift entries with the same hash.
int last, slot;
K curr;
final K[] key = this.key;
for ( ;; ) {
pos = ( ( last = pos ) + 1 ) & mask;
for ( ;; ) {
if ( ( ( curr = key[ pos ] ) == ( null ) ) ) {
key[ last ] = ( null );
return;
}
slot = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( curr ) ) ) & mask;
if ( last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos ) break;
pos = ( pos + 1 ) & mask;
}
key[ last ] = curr;
fixPointers( pos, last );
}
}
private boolean removeEntry( final int pos ) {
size--;
fixPointers( pos );
shiftKeys( pos );
if ( size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE ) rehash( n / 2 );
return true;
}
private boolean removeNullEntry() {
containsNull = false;
size--;
fixPointers( n );
if ( size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE ) rehash( n / 2 );
return true;
}
public boolean remove( final Object k ) {
if ( ( ( k ) == ( null ) ) ) {
if ( containsNull ) return removeNullEntry();
return false;
}
K curr;
final K[] key = this.key;
int pos;
// The starting point.
if ( ( ( curr = key[ pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( k ) ) ) & mask ] ) == ( null ) ) ) return false;
if ( ( ( k ) == ( curr ) ) ) return removeEntry( pos );
while ( true ) {
if ( ( ( curr = key[ pos = ( pos + 1 ) & mask ] ) == ( null ) ) ) return false;
if ( ( ( k ) == ( curr ) ) ) return removeEntry( pos );
}
}
public boolean contains( final Object k ) {
if ( ( ( k ) == ( null ) ) ) return containsNull;
K curr;
final K[] key = this.key;
int pos;
// The starting point.
if ( ( ( curr = key[ pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( k ) ) ) & mask ] ) == ( null ) ) ) return false;
if ( ( ( k ) == ( curr ) ) ) return true;
while ( true ) {
if ( ( ( curr = key[ pos = ( pos + 1 ) & mask ] ) == ( null ) ) ) return false;
if ( ( ( k ) == ( curr ) ) ) return true;
}
}
/** Removes the first key in iteration order.
*
* @return the first key.
* @throws NoSuchElementException is this set is empty. */
public K removeFirst() {
if ( size == 0 ) throw new NoSuchElementException();
final int pos = first;
// Abbreviated version of fixPointers(pos)
first = (int)link[ pos ];
if ( 0 <= first ) {
// Special case of SET_PREV( link[ first ], -1 )
link[ first ] |= ( -1 & 0xFFFFFFFFL ) << 32;
}
final K k = key[ pos ];
size--;
if ( ( ( k ) == ( null ) ) ) containsNull = false;
else shiftKeys( pos );
if ( size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE ) rehash( n / 2 );
return k;
}
/** Removes the the last key in iteration order.
*
* @return the last key.
* @throws NoSuchElementException is this set is empty. */
public K removeLast() {
if ( size == 0 ) throw new NoSuchElementException();
final int pos = last;
// Abbreviated version of fixPointers(pos)
last = (int)( link[ pos ] >>> 32 );
if ( 0 <= last ) {
// Special case of SET_NEXT( link[ last ], -1 )
link[ last ] |= -1 & 0xFFFFFFFFL;
}
final K k = key[ pos ];
size--;
if ( ( ( k ) == ( null ) ) ) containsNull = false;
else shiftKeys( pos );
if ( size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE ) rehash( n / 2 );
return k;
}
private void moveIndexToFirst( final int i ) {
if ( size == 1 || first == i ) return;
if ( last == i ) {
last = (int)( link[ i ] >>> 32 );
// Special case of SET_NEXT( link[ last ], -1 );
link[ last ] |= -1 & 0xFFFFFFFFL;
}
else {
final long linki = link[ i ];
final int prev = (int)( linki >>> 32 );
final int next = (int)linki;
link[ prev ] ^= ( ( link[ prev ] ^ ( linki & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ next ] ^= ( ( link[ next ] ^ ( linki & 0xFFFFFFFF00000000L ) ) & 0xFFFFFFFF00000000L );
}
link[ first ] ^= ( ( link[ first ] ^ ( ( i & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
link[ i ] = ( ( -1 & 0xFFFFFFFFL ) << 32 ) | ( first & 0xFFFFFFFFL );
first = i;
}
private void moveIndexToLast( final int i ) {
if ( size == 1 || last == i ) return;
if ( first == i ) {
first = (int)link[ i ];
// Special case of SET_PREV( link[ first ], -1 );
link[ first ] |= ( -1 & 0xFFFFFFFFL ) << 32;
}
else {
final long linki = link[ i ];
final int prev = (int)( linki >>> 32 );
final int next = (int)linki;
link[ prev ] ^= ( ( link[ prev ] ^ ( linki & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ next ] ^= ( ( link[ next ] ^ ( linki & 0xFFFFFFFF00000000L ) ) & 0xFFFFFFFF00000000L );
}
link[ last ] ^= ( ( link[ last ] ^ ( i & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ i ] = ( ( last & 0xFFFFFFFFL ) << 32 ) | ( -1 & 0xFFFFFFFFL );
last = i;
}
/** Adds a key to the set; if the key is already present, it is moved to the first position of the iteration order.
*
* @param k the key.
* @return true if the key was not present. */
public boolean addAndMoveToFirst( final K k ) {
int pos;
if ( ( ( k ) == ( null ) ) ) {
if ( containsNull ) {
moveIndexToFirst( n );
return false;
}
containsNull = true;
pos = n;
}
else {
// The starting point.
final K key[] = this.key;
pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( k ) ) ) & mask;
// There's always an unused entry. TODO
while ( !( ( key[ pos ] ) == ( null ) ) ) {
if ( ( ( k ) == ( key[ pos ] ) ) ) {
moveIndexToFirst( pos );
return false;
}
pos = ( pos + 1 ) & mask;
}
key[ pos ] = k;
}
if ( size == 0 ) {
first = last = pos;
// Special case of SET_UPPER_LOWER( link[ pos ], -1, -1 );
link[ pos ] = -1L;
}
else {
link[ first ] ^= ( ( link[ first ] ^ ( ( pos & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
link[ pos ] = ( ( -1 & 0xFFFFFFFFL ) << 32 ) | ( first & 0xFFFFFFFFL );
first = pos;
}
if ( size++ >= maxFill ) rehash( arraySize( size, f ) );
if ( ASSERTS ) checkTable();
return true;
}
/** Adds a key to the set; if the key is already present, it is moved to the last position of the iteration order.
*
* @param k the key.
* @return true if the key was not present. */
public boolean addAndMoveToLast( final K k ) {
int pos;
if ( ( ( k ) == ( null ) ) ) {
if ( containsNull ) {
moveIndexToLast( n );
return false;
}
containsNull = true;
pos = n;
}
else {
// The starting point.
final K key[] = this.key;
pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( k ) ) ) & mask;
// There's always an unused entry.
while ( !( ( key[ pos ] ) == ( null ) ) ) {
if ( ( ( k ) == ( key[ pos ] ) ) ) {
moveIndexToLast( pos );
return false;
}
pos = ( pos + 1 ) & mask;
}
key[ pos ] = k;
}
if ( size == 0 ) {
first = last = pos;
// Special case of SET_UPPER_LOWER( link[ pos ], -1, -1 );
link[ pos ] = -1L;
}
else {
link[ last ] ^= ( ( link[ last ] ^ ( pos & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ pos ] = ( ( last & 0xFFFFFFFFL ) << 32 ) | ( -1 & 0xFFFFFFFFL );
last = pos;
}
if ( size++ >= maxFill ) rehash( arraySize( size, f ) );
if ( ASSERTS ) checkTable();
return true;
}
/* Removes all elements from this set.
*
*
To increase object reuse, this method does not change the table size. If you want to reduce the table size, you must use {@link #trim()}. */
public void clear() {
if ( size == 0 ) return;
size = 0;
containsNull = false;
Arrays.fill( key, ( null ) );
first = last = -1;
}
public int size() {
return size;
}
public boolean isEmpty() {
return size == 0;
}
/** A no-op for backward compatibility.
*
* @param growthFactor unused.
* @deprecated Since fastutil 6.1.0, hash tables are doubled when they are too full. */
@Deprecated
public void growthFactor( int growthFactor ) {}
/** Gets the growth factor (2).
*
* @return the growth factor of this set, which is fixed (2).
* @see #growthFactor(int)
* @deprecated Since fastutil 6.1.0, hash tables are doubled when they are too full. */
@Deprecated
public int growthFactor() {
return 16;
}
/** Modifies the {@link #link} vector so that the given entry is removed. This method will complete in constant time.
*
* @param i the index of an entry. */
protected void fixPointers( final int i ) {
if ( size == 0 ) {
first = last = -1;
return;
}
if ( first == i ) {
first = (int)link[ i ];
if ( 0 <= first ) {
// Special case of SET_PREV( link[ first ], -1 )
link[ first ] |= ( -1 & 0xFFFFFFFFL ) << 32;
}
return;
}
if ( last == i ) {
last = (int)( link[ i ] >>> 32 );
if ( 0 <= last ) {
// Special case of SET_NEXT( link[ last ], -1 )
link[ last ] |= -1 & 0xFFFFFFFFL;
}
return;
}
final long linki = link[ i ];
final int prev = (int)( linki >>> 32 );
final int next = (int)linki;
link[ prev ] ^= ( ( link[ prev ] ^ ( linki & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ next ] ^= ( ( link[ next ] ^ ( linki & 0xFFFFFFFF00000000L ) ) & 0xFFFFFFFF00000000L );
}
/** Modifies the {@link #link} vector for a shift from s to d. This method will complete in constant time.
*
* @param s the source position.
* @param d the destination position. */
protected void fixPointers( int s, int d ) {
if ( size == 1 ) {
first = last = d;
// Special case of SET(link[ d ], -1, -1)
link[ d ] = -1L;
return;
}
if ( first == s ) {
first = d;
link[ (int)link[ s ] ] ^= ( ( link[ (int)link[ s ] ] ^ ( ( d & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
link[ d ] = link[ s ];
return;
}
if ( last == s ) {
last = d;
link[ (int)( link[ s ] >>> 32 ) ] ^= ( ( link[ (int)( link[ s ] >>> 32 ) ] ^ ( d & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ d ] = link[ s ];
return;
}
final long links = link[ s ];
final int prev = (int)( links >>> 32 );
final int next = (int)links;
link[ prev ] ^= ( ( link[ prev ] ^ ( d & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ next ] ^= ( ( link[ next ] ^ ( ( d & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
link[ d ] = links;
}
/** Returns the first element of this set in iteration order.
*
* @return the first element in iteration order. */
public K first() {
if ( size == 0 ) throw new NoSuchElementException();
return key[ first ];
}
/** Returns the last element of this set in iteration order.
*
* @return the last element in iteration order. */
public K last() {
if ( size == 0 ) throw new NoSuchElementException();
return key[ last ];
}
public ReferenceSortedSet tailSet( K from ) {
throw new UnsupportedOperationException();
}
public ReferenceSortedSet headSet( K to ) {
throw new UnsupportedOperationException();
}
public ReferenceSortedSet subSet( K from, K to ) {
throw new UnsupportedOperationException();
}
public Comparator comparator() {
return null;
}
/** A list iterator over a linked set.
*
* This class provides a list iterator over a linked hash set. The constructor runs in constant time. */
private class SetIterator extends AbstractObjectListIterator {
/** The entry that will be returned by the next call to {@link java.util.ListIterator#previous()} (or null if no previous entry exists). */
int prev = -1;
/** The entry that will be returned by the next call to {@link java.util.ListIterator#next()} (or null if no next entry exists). */
int next = -1;
/** The last entry that was returned (or -1 if we did not iterate or used {@link #remove()}). */
int curr = -1;
/** The current index (in the sense of a {@link java.util.ListIterator}). When -1, we do not know the current index. */
int index = -1;
SetIterator() {
next = first;
index = 0;
}
SetIterator( K from ) {
if ( ( ( from ) == ( null ) ) ) {
if ( ReferenceLinkedOpenHashSet.this.containsNull ) {
next = (int)link[ n ];
prev = n;
return;
}
else throw new NoSuchElementException( "The key " + from + " does not belong to this set." );
}
if ( ( ( key[ last ] ) == ( from ) ) ) {
prev = last;
index = size;
return;
}
// The starting point.
final K key[] = ReferenceLinkedOpenHashSet.this.key;
int pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( from ) ) ) & mask;
// There's always an unused entry.
while ( !( ( key[ pos ] ) == ( null ) ) ) {
if ( ( ( key[ pos ] ) == ( from ) ) ) {
// Note: no valid index known.
next = (int)link[ pos ];
prev = pos;
return;
}
pos = ( pos + 1 ) & mask;
}
throw new NoSuchElementException( "The key " + from + " does not belong to this set." );
}
public boolean hasNext() {
return next != -1;
}
public boolean hasPrevious() {
return prev != -1;
}
public K next() {
if ( !hasNext() ) throw new NoSuchElementException();
curr = next;
next = (int)link[ curr ];
prev = curr;
if ( index >= 0 ) index++;
if ( ASSERTS ) assert curr == n || !( ( key[ curr ] ) == ( null ) ) : "Position " + curr + " is not used";
return key[ curr ];
}
public K previous() {
if ( !hasPrevious() ) throw new NoSuchElementException();
curr = prev;
prev = (int)( link[ curr ] >>> 32 );
next = curr;
if ( index >= 0 ) index--;
return key[ curr ];
}
private final void ensureIndexKnown() {
if ( index >= 0 ) return;
if ( prev == -1 ) {
index = 0;
return;
}
if ( next == -1 ) {
index = size;
return;
}
int pos = first;
index = 1;
while ( pos != prev ) {
pos = (int)link[ pos ];
index++;
}
}
public int nextIndex() {
ensureIndexKnown();
return index;
}
public int previousIndex() {
ensureIndexKnown();
return index - 1;
}
public void remove() {
ensureIndexKnown();
if ( curr == -1 ) throw new IllegalStateException();
if ( curr == prev ) {
/*
* If the last operation was a next(), we are removing an entry that preceeds the current index, and thus we must decrement it. */
index--;
prev = (int)( link[ curr ] >>> 32 );
}
else next = (int)link[ curr ];
size--;
/*
* Now we manually fix the pointers. Because of our knowledge of next and prev, this is going to be faster than calling fixPointers(). */
if ( prev == -1 ) first = next;
else link[ prev ] ^= ( ( link[ prev ] ^ ( next & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
if ( next == -1 ) last = prev;
else link[ next ] ^= ( ( link[ next ] ^ ( ( prev & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
int last, slot, pos = curr;
curr = -1;
if ( pos == n ) ReferenceLinkedOpenHashSet.this.containsNull = false;
else {
K curr;
final K[] key = ReferenceLinkedOpenHashSet.this.key;
// We have to horribly duplicate the shiftKeys() code because we need to update next/prev.
for ( ;; ) {
pos = ( ( last = pos ) + 1 ) & mask;
for ( ;; ) {
if ( ( ( curr = key[ pos ] ) == ( null ) ) ) {
key[ last ] = ( null );
return;
}
slot = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( curr ) ) ) & mask;
if ( last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos ) break;
pos = ( pos + 1 ) & mask;
}
key[ last ] = curr;
if ( next == pos ) next = last;
if ( prev == pos ) prev = last;
fixPointers( pos, last );
}
}
}
}
/** Returns a type-specific list iterator on the elements in this set, starting from a given element of the set. Please see the class documentation for implementation details.
*
* @param from an element to start from.
* @return a type-specific list iterator starting at the given element.
* @throws IllegalArgumentException if from does not belong to the set. */
public ObjectListIterator iterator( K from ) {
return new SetIterator( from );
}
public ObjectListIterator iterator() {
return new SetIterator();
}
/** A no-op for backward compatibility. The kind of tables implemented by this class never need rehashing.
*
* If you need to reduce the table size to fit exactly this set, use {@link #trim()}.
*
* @return true.
* @see #trim()
* @deprecated A no-op. */
@Deprecated
public boolean rehash() {
return true;
}
/** Rehashes this set, making the table as small as possible.
*
*
This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.
*
*
If the table size is already the minimum possible, this method does nothing.
*
* @return true if there was enough memory to trim the set.
* @see #trim(int) */
public boolean trim() {
final int l = arraySize( size, f );
if ( l >= n ) return true;
try {
rehash( l );
}
catch ( OutOfMemoryError cantDoIt ) {
return false;
}
return true;
}
/** Rehashes this set if the table is too large.
*
*
Let N be the smallest table size that can hold max(n,{@link #size()}) entries, still satisfying the load factor. If the current table size is smaller than or equal to
* N, this method does nothing. Otherwise, it rehashes this set in a table of size N.
*
*
This method is useful when reusing sets. {@linkplain #clear() Clearing a set} leaves the table size untouched. If you are reusing a set many times, you can call this method with a typical
* size to avoid keeping around a very large table just because of a few large transient sets.
*
* @param n the threshold for the trimming.
* @return true if there was enough memory to trim the set.
* @see #trim() */
public boolean trim( final int n ) {
final int l = HashCommon.nextPowerOfTwo( (int)Math.ceil( n / f ) );
if ( this.n <= l ) return true;
try {
rehash( l );
}
catch ( OutOfMemoryError cantDoIt ) {
return false;
}
return true;
}
/** Rehashes the set.
*
*
This method implements the basic rehashing strategy, and may be overriden by subclasses implementing different rehashing strategies (e.g., disk-based rehashing). However, you should not
* override this method unless you understand the internal workings of this class.
*
* @param newN the new size */
@SuppressWarnings("unchecked")
protected void rehash( final int newN ) {
final K key[] = this.key;
final int mask = newN - 1; // Note that this is used by the hashing macro
final K newKey[] = (K[])new Object[ newN + 1 ];
int i = first, prev = -1, newPrev = -1, t, pos;
final long link[] = this.link;
final long newLink[] = new long[ newN + 1 ];
first = -1;
for ( int j = size; j-- != 0; ) {
if ( ( ( key[ i ] ) == ( null ) ) ) pos = newN;
else {
pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( key[ i ] ) ) ) & mask;
while ( !( ( newKey[ pos ] ) == ( null ) ) )
pos = ( pos + 1 ) & mask;
newKey[ pos ] = key[ i ];
}
if ( prev != -1 ) {
newLink[ newPrev ] ^= ( ( newLink[ newPrev ] ^ ( pos & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
newLink[ pos ] ^= ( ( newLink[ pos ] ^ ( ( newPrev & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
newPrev = pos;
}
else {
newPrev = first = pos;
// Special case of SET(newLink[ pos ], -1, -1);
newLink[ pos ] = -1L;
}
t = i;
i = (int)link[ i ];
prev = t;
}
this.link = newLink;
this.last = newPrev;
if ( newPrev != -1 )
// Special case of SET_NEXT( newLink[ newPrev ], -1 );
newLink[ newPrev ] |= -1 & 0xFFFFFFFFL;
n = newN;
this.mask = mask;
maxFill = maxFill( n, f );
this.key = newKey;
}
/** Returns a deep copy of this set.
*
*
This method performs a deep copy of this hash set; the data stored in the set, however, is not cloned. Note that this makes a difference only for object keys.
*
* @return a deep copy of this set. */
@SuppressWarnings("unchecked")
public ReferenceLinkedOpenHashSet clone() {
ReferenceLinkedOpenHashSet c;
try {
c = (ReferenceLinkedOpenHashSet)super.clone();
}
catch ( CloneNotSupportedException cantHappen ) {
throw new InternalError();
}
c.key = key.clone();
c.containsNull = containsNull;
c.link = link.clone();
return c;
}
/** Returns a hash code for this set.
*
* This method overrides the generic method provided by the superclass. Since equals() is not overriden, it is important that the value returned by this method is the same value as
* the one returned by the overriden method.
*
* @return a hash code for this set. */
public int hashCode() {
int h = 0;
for ( int j = realSize(), i = 0; j-- != 0; ) {
while ( ( ( key[ i ] ) == ( null ) ) )
i++;
if ( this != key[ i ] ) h += ( System.identityHashCode( key[ i ] ) );
i++;
}
// Zero / null have hash zero.
return h;
}
private void writeObject( java.io.ObjectOutputStream s ) throws java.io.IOException {
final ObjectIterator i = iterator();
s.defaultWriteObject();
for ( int j = size; j-- != 0; )
s.writeObject( i.next() );
}
@SuppressWarnings("unchecked")
private void readObject( java.io.ObjectInputStream s ) throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject();
n = arraySize( size, f );
maxFill = maxFill( n, f );
mask = n - 1;
final K key[] = this.key = (K[])new Object[ n + 1 ];
final long link[] = this.link = new long[ n + 1 ];
int prev = -1;
first = last = -1;
K k;
for ( int i = size, pos; i-- != 0; ) {
k = (K)s.readObject();
if ( ( ( k ) == ( null ) ) ) {
pos = n;
containsNull = true;
}
else {
if ( !( ( key[ pos = ( it.unimi.dsi.fastutil.HashCommon.mix( System.identityHashCode( k ) ) ) & mask ] ) == ( null ) ) ) while ( !( ( key[ pos = ( pos + 1 ) & mask ] ) == ( null ) ) );
key[ pos ] = k;
}
if ( first != -1 ) {
link[ prev ] ^= ( ( link[ prev ] ^ ( pos & 0xFFFFFFFFL ) ) & 0xFFFFFFFFL );
link[ pos ] ^= ( ( link[ pos ] ^ ( ( prev & 0xFFFFFFFFL ) << 32 ) ) & 0xFFFFFFFF00000000L );
prev = pos;
}
else {
prev = first = pos;
// Special case of SET_PREV( newLink[ pos ], -1 );
link[ pos ] |= ( -1L & 0xFFFFFFFFL ) << 32;
}
}
last = prev;
if ( prev != -1 )
// Special case of SET_NEXT( link[ prev ], -1 );
link[ prev ] |= -1 & 0xFFFFFFFFL;
if ( ASSERTS ) checkTable();
}
private void checkTable() {}
}