src.it.unimi.dsi.fastutil.bytes.Byte2LongOpenHashMap Maven / Gradle / Ivy
/* 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) */
/* Primitive-type-only definitions (keys) */
/* Object/Reference-only definitions (values) */
/* Primitive-type-only definitions (values) */
/*
* Copyright (C) 2002-2013 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.bytes;
import it.unimi.dsi.fastutil.Hash;
import it.unimi.dsi.fastutil.HashCommon;
import it.unimi.dsi.fastutil.booleans.BooleanArrays;
import static it.unimi.dsi.fastutil.HashCommon.arraySize;
import static it.unimi.dsi.fastutil.HashCommon.maxFill;
import java.util.Map;
import java.util.NoSuchElementException;
import it.unimi.dsi.fastutil.longs.LongCollection;
import it.unimi.dsi.fastutil.longs.AbstractLongCollection;
import it.unimi.dsi.fastutil.longs.LongIterator;
import it.unimi.dsi.fastutil.objects.AbstractObjectSet;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
/** A type-specific hash map with a fast, small-footprint implementation.
*
* Instances of this class use a hash table to represent a map. The table is
* enlarged as needed by doubling its size when new entries are created, but it is never made
* smaller (even on a {@link #clear()}). 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.
*
*
Warning: The implementation of this class has significantly
* changed in fastutil 6.1.0. Please read the
* comments about this issue in the section “Faster Hash Tables” of the overview.
*
* @see Hash
* @see HashCommon
*/
public class Byte2LongOpenHashMap extends AbstractByte2LongMap implements java.io.Serializable, Cloneable, Hash {
private static final long serialVersionUID = 0L;
private static final boolean ASSERTS = false;
/** The array of keys. */
protected transient byte key[];
/** The array of values. */
protected transient long value[];
/** The array telling whether a position is used. */
protected transient boolean used[];
/** The acceptable load factor. */
protected final float f;
/** 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;
/** The mask for wrapping a position counter. */
protected transient int mask;
/** Number of entries in the set. */
protected int size;
/** Cached set of entries. */
protected transient volatile FastEntrySet entries;
/** Cached set of keys. */
protected transient volatile ByteSet keys;
/** Cached collection of values. */
protected transient volatile LongCollection values;
/** Creates a new hash map.
*
*
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 Byte2LongOpenHashMap( 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 = new byte[ n ];
value = new long[ n ];
used = new boolean[ n ];
}
/** Creates a new hash map with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor.
*
* @param expected the expected number of elements in the hash map.
*/
public Byte2LongOpenHashMap( final int expected ) {
this( expected, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash map with initial expected {@link Hash#DEFAULT_INITIAL_SIZE} entries
* and {@link Hash#DEFAULT_LOAD_FACTOR} as load factor.
*/
public Byte2LongOpenHashMap() {
this( DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash map copying a given one.
*
* @param m a {@link Map} to be copied into the new hash map.
* @param f the load factor.
*/
public Byte2LongOpenHashMap( final Map m, final float f ) {
this( m.size(), f );
putAll( m );
}
/** Creates a new hash map with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor copying a given one.
*
* @param m a {@link Map} to be copied into the new hash map.
*/
public Byte2LongOpenHashMap( final Map m ) {
this( m, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash map copying a given type-specific one.
*
* @param m a type-specific map to be copied into the new hash map.
* @param f the load factor.
*/
public Byte2LongOpenHashMap( final Byte2LongMap m, final float f ) {
this( m.size(), f );
putAll( m );
}
/** Creates a new hash map with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor copying a given type-specific one.
*
* @param m a type-specific map to be copied into the new hash map.
*/
public Byte2LongOpenHashMap( final Byte2LongMap m ) {
this( m, DEFAULT_LOAD_FACTOR );
}
/** Creates a new hash map using the elements of two parallel arrays.
*
* @param k the array of keys of the new hash map.
* @param v the array of corresponding values in the new hash map.
* @param f the load factor.
* @throws IllegalArgumentException if k and v have different lengths.
*/
public Byte2LongOpenHashMap( final byte[] k, final long v[], final float f ) {
this( k.length, f );
if ( k.length != v.length ) throw new IllegalArgumentException( "The key array and the value array have different lengths (" + k.length + " and " + v.length + ")" );
for( int i = 0; i < k.length; i++ ) this.put( k[ i ], v[ i ] );
}
/** Creates a new hash map with {@link Hash#DEFAULT_LOAD_FACTOR} as load factor using the elements of two parallel arrays.
*
* @param k the array of keys of the new hash map.
* @param v the array of corresponding values in the new hash map.
* @throws IllegalArgumentException if k and v have different lengths.
*/
public Byte2LongOpenHashMap( final byte[] k, final long v[] ) {
this( k, v, DEFAULT_LOAD_FACTOR );
}
/*
* The following methods implements some basic building blocks used by
* all accessors. They are (and should be maintained) identical to those used in OpenHashSet.drv.
*/
public long put(final byte k, final long v) {
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) {
final long oldValue = value[ pos ];
value[ pos ] = v;
return oldValue;
}
pos = ( pos + 1 ) & mask;
}
used[ pos ] = true;
key[ pos ] = k;
value[ pos ] = v;
if ( ++size >= maxFill ) rehash( arraySize( size + 1, f ) );
if ( ASSERTS ) checkTable();
return defRetValue;
}
public Long put( final Byte ok, final Long ov ) {
final long v = ((ov).longValue());
final byte k = ((ok).byteValue());
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) {
final Long oldValue = (Long.valueOf(value[ pos ]));
value[ pos ] = v;
return oldValue;
}
pos = ( pos + 1 ) & mask;
}
used[ pos ] = true;
key[ pos ] = k;
value[ pos ] = v;
if ( ++size >= maxFill ) rehash( arraySize( size + 1, f ) );
if ( ASSERTS ) checkTable();
return (null);
}
/** Adds an increment to value currently associated with a key.
*
* @param k the key.
* @param incr the increment.
* @return the old value, or the {@linkplain #defaultReturnValue() default return value} if no value was present for the given key.
* @deprecated use addTo() instead; having the same name of a {@link java.util.Set} method turned out to be a recipe for disaster.
*/
@Deprecated
public long add(final byte k, final long incr) {
return addTo( k, incr );
}
/** Adds an increment to value currently associated with a key.
*
*
Note that this method respects the {@linkplain #defaultReturnValue() default return value} semantics: when
* called with a key that does not currently appears in the map, the key
* will be associated with the default return value plus
* the given increment.
*
* @param k the key.
* @param incr the increment.
* @return the old value, or the {@linkplain #defaultReturnValue() default return value} if no value was present for the given key.
*/
public long addTo(final byte k, final long incr) {
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) {
final long oldValue = value[ pos ];
value[ pos ] += incr;
return oldValue;
}
pos = ( pos + 1 ) & mask;
}
used[ pos ] = true;
key[ pos ] = k;
value[ pos ] = defRetValue + incr;
if ( ++size >= maxFill ) rehash( arraySize( size + 1, f ) );
if ( ASSERTS ) checkTable();
return defRetValue;
}
/** Shifts left entries with the specified hash code, starting at the specified position,
* and empties the resulting free entry.
*
* @param pos a starting position.
* @return the position cleared by the shifting process.
*/
protected final int shiftKeys( int pos ) {
// Shift entries with the same hash.
int last, slot;
for(;;) {
pos = ( ( last = pos ) + 1 ) & mask;
while( used[ pos ] ) {
slot = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (key[ pos ]) ) ) & mask;
if ( last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos ) break;
pos = ( pos + 1 ) & mask;
}
if ( ! used[ pos ] ) break;
key[ last ] = key[ pos ];
value[ last ] = value[ pos ];
}
used[ last ] = false;
return last;
}
@SuppressWarnings("unchecked")
public long remove( final byte k ) {
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) {
size--;
final long v = value[ pos ];
shiftKeys( pos );
return v;
}
pos = ( pos + 1 ) & mask;
}
return defRetValue;
}
@SuppressWarnings("unchecked")
public Long remove( final Object ok ) {
final byte k = ((((Byte)(ok)).byteValue()));
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) {
size--;
final long v = value[ pos ];
shiftKeys( pos );
return (Long.valueOf(v));
}
pos = ( pos + 1 ) & mask;
}
return (null);
}
public Long get( final Byte ok ) {
final byte k = ((ok).byteValue());
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( ( k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == ( k) ) ) return (Long.valueOf(value[ pos ]));
pos = ( pos + 1 ) & mask;
}
return (null);
}
@SuppressWarnings("unchecked")
public long get( final byte k ) {
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) return value[ pos ];
pos = ( pos + 1 ) & mask;
}
return defRetValue;
}
@SuppressWarnings("unchecked")
public boolean containsKey( final byte k ) {
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) return true;
pos = ( pos + 1 ) & mask;
}
return false;
}
public boolean containsValue( final long v ) {
final long value[] = this.value;
final boolean used[] = this.used;
for( int i = n; i-- != 0; ) if ( used[ i ] && ( (value[ i ]) == (v) ) ) return true;
return false;
}
/* Removes all elements from this map.
*
*
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;
BooleanArrays.fill( used, false );
// We null all object entries so that the garbage collector can do its work.
}
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;
}
/** The entry class for a hash map does not record key and value, but
* rather the position in the hash table of the corresponding entry. This
* is necessary so that calls to {@link java.util.Map.Entry#setValue(Object)} are reflected in
* the map */
private final class MapEntry implements Byte2LongMap.Entry , Map.Entry {
// The table index this entry refers to, or -1 if this entry has been deleted.
private int index;
MapEntry( final int index ) {
this.index = index;
}
public Byte getKey() {
return (Byte.valueOf(key[ index ]));
}
public byte getByteKey() {
return key[ index ];
}
public Long getValue() {
return (Long.valueOf(value[ index ]));
}
public long getLongValue() {
return value[ index ];
}
public long setValue( final long v ) {
final long oldValue = value[ index ];
value[ index ] = v;
return oldValue;
}
public Long setValue( final Long v ) {
return (Long.valueOf(setValue( ((v).longValue()) )));
}
@SuppressWarnings("unchecked")
public boolean equals( final Object o ) {
if (!(o instanceof Map.Entry)) return false;
Map.Entry e = (Map.Entry)o;
return ( (key[ index ]) == (((e.getKey()).byteValue())) ) && ( (value[ index ]) == (((e.getValue()).longValue())) );
}
public int hashCode() {
return (key[ index ]) ^ it.unimi.dsi.fastutil.HashCommon.long2int(value[ index ]);
}
public String toString() {
return key[ index ] + "=>" + value[ index ];
}
}
/** An iterator over a hash map. */
private class MapIterator {
/** The index of the next entry to be returned, if positive or zero. If negative, the next entry to be
returned, if any, is that of index -pos -2 from the {@link #wrapped} list. */
int pos = Byte2LongOpenHashMap.this.n;
/** The index of the last entry that has been returned. It is -1 if either
we did not return an entry yet, or the last returned entry has been removed. */
int last = -1;
/** A downward counter measuring how many entries must still be returned. */
int c = size;
/** A lazily allocated list containing the keys of elements that have wrapped around the table because of removals; such elements
would not be enumerated (other elements would be usually enumerated twice in their place). */
ByteArrayList wrapped;
{
final boolean used[] = Byte2LongOpenHashMap.this.used;
if ( c != 0 ) while( ! used[ --pos ] );
}
public boolean hasNext() {
return c != 0;
}
public int nextEntry() {
if ( ! hasNext() ) throw new NoSuchElementException();
c--;
// We are just enumerating elements from the wrapped list.
if ( pos < 0 ) {
final byte k = wrapped.getByte( - ( last = --pos ) - 2 );
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) return pos;
pos = ( pos + 1 ) & mask;
}
}
last = pos;
//System.err.println( "Count: " + c );
if ( c != 0 ) {
final boolean used[] = Byte2LongOpenHashMap.this.used;
while ( pos-- != 0 && !used[ pos ] );
// When here pos < 0 there are no more elements to be enumerated by scanning, but wrapped might be nonempty.
}
return last;
}
/** Shifts left entries with the specified hash code, starting at the specified position,
* and empties the resulting free entry. If any entry wraps around the table, instantiates
* lazily {@link #wrapped} and stores the entry key.
*
* @param pos a starting position.
* @return the position cleared by the shifting process.
*/
protected final int shiftKeys( int pos ) {
// Shift entries with the same hash.
int last, slot;
for(;;) {
pos = ( ( last = pos ) + 1 ) & mask;
while( used[ pos ] ) {
slot = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (key[ pos ]) ) ) & mask;
if ( last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos ) break;
pos = ( pos + 1 ) & mask;
}
if ( ! used[ pos ] ) break;
if ( pos < last ) {
// Wrapped entry.
if ( wrapped == null ) wrapped = new ByteArrayList ();
wrapped.add( key[ pos ] );
}
key[ last ] = key[ pos ];
value[ last ] = value[ pos ];
}
used[ last ] = false;
return last;
}
@SuppressWarnings("unchecked")
public void remove() {
if ( last == -1 ) throw new IllegalStateException();
if ( pos < -1 ) {
// We're removing wrapped entries.
Byte2LongOpenHashMap.this.remove( wrapped.getByte( - pos - 2 ) );
last = -1;
return;
}
size--;
if ( shiftKeys( last ) == pos && c > 0 ) {
c++;
nextEntry();
}
last = -1; // You can no longer remove this entry.
if ( ASSERTS ) checkTable();
}
public int skip( final int n ) {
int i = n;
while( i-- != 0 && hasNext() ) nextEntry();
return n - i - 1;
}
}
private class EntryIterator extends MapIterator implements ObjectIterator {
private MapEntry entry;
public Byte2LongMap.Entry next() {
return entry = new MapEntry( nextEntry() );
}
@Override
public void remove() {
super.remove();
entry.index = -1; // You cannot use a deleted entry.
}
}
private class FastEntryIterator extends MapIterator implements ObjectIterator {
final BasicEntry entry = new BasicEntry ( ((byte)0), (0) );
public BasicEntry next() {
final int e = nextEntry();
entry.key = key[ e ];
entry.value = value[ e ];
return entry;
}
}
private final class MapEntrySet extends AbstractObjectSet implements FastEntrySet {
public ObjectIterator iterator() {
return new EntryIterator();
}
public ObjectIterator fastIterator() {
return new FastEntryIterator();
}
@SuppressWarnings("unchecked")
public boolean contains( final Object o ) {
if ( !( o instanceof Map.Entry ) ) return false;
final Map.Entry e = (Map.Entry)o;
final byte k = ((e.getKey()).byteValue());
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) return ( (value[ pos ]) == (((e.getValue()).longValue())) );
pos = ( pos + 1 ) & mask;
}
return false;
}
@SuppressWarnings("unchecked")
public boolean remove( final Object o ) {
if ( !( o instanceof Map.Entry ) ) return false;
final Map.Entry e = (Map.Entry)o;
final byte k = ((e.getKey()).byteValue());
// The starting point.
int pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
// There's always an unused entry.
while( used[ pos ] ) {
if ( ( (key[ pos ]) == (k) ) ) {
Byte2LongOpenHashMap.this.remove( e.getKey() );
return true;
}
pos = ( pos + 1 ) & mask;
}
return false;
}
public int size() {
return size;
}
public void clear() {
Byte2LongOpenHashMap.this.clear();
}
}
public FastEntrySet byte2LongEntrySet() {
if ( entries == null ) entries = new MapEntrySet();
return entries;
}
/** An iterator on keys.
*
* We simply override the {@link java.util.ListIterator#next()}/{@link java.util.ListIterator#previous()} methods
* (and possibly their type-specific counterparts) so that they return keys
* instead of entries.
*/
private final class KeyIterator extends MapIterator implements ByteIterator {
public KeyIterator() { super(); }
public byte nextByte() { return key[ nextEntry() ]; }
public Byte next() { return (Byte.valueOf(key[ nextEntry() ])); }
}
private final class KeySet extends AbstractByteSet {
public ByteIterator iterator() {
return new KeyIterator();
}
public int size() {
return size;
}
public boolean contains( byte k ) {
return containsKey( k );
}
public boolean remove( byte k ) {
final int oldSize = size;
Byte2LongOpenHashMap.this.remove( k );
return size != oldSize;
}
public void clear() {
Byte2LongOpenHashMap.this.clear();
}
}
public ByteSet keySet() {
if ( keys == null ) keys = new KeySet();
return keys;
}
/** An iterator on values.
*
*
We simply override the {@link java.util.ListIterator#next()}/{@link java.util.ListIterator#previous()} methods
* (and possibly their type-specific counterparts) so that they return values
* instead of entries.
*/
private final class ValueIterator extends MapIterator implements LongIterator {
public ValueIterator() { super(); }
public long nextLong() { return value[ nextEntry() ]; }
public Long next() { return (Long.valueOf(value[ nextEntry() ])); }
}
public LongCollection values() {
if ( values == null ) values = new AbstractLongCollection () {
public LongIterator iterator() {
return new ValueIterator();
}
public int size() {
return size;
}
public boolean contains( long v ) {
return containsValue( v );
}
public void clear() {
Byte2LongOpenHashMap.this.clear();
}
};
return values;
}
/** 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 the map, 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 map.
* @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 map 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 map in a table of size
* N.
*
*
This method is useful when reusing maps. {@linkplain #clear() Clearing a
* map} leaves the table size untouched. If you are reusing a map
* 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 maps.
*
* @param n the threshold for the trimming.
* @return true if there was enough memory to trim the map.
* @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 map.
*
*
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 ) {
int i = 0, pos;
final boolean used[] = this.used;
byte k;
final byte key[] = this.key;
final long value[] = this.value;
final int newMask = newN - 1;
final byte newKey[] = new byte[ newN ];
final long newValue[] = new long[newN];
final boolean newUsed[] = new boolean[ newN ];
for( int j = size; j-- != 0; ) {
while( ! used[ i ] ) i++;
k = key[ i ];
pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & newMask;
while ( newUsed[ pos ] ) pos = ( pos + 1 ) & newMask;
newUsed[ pos ] = true;
newKey[ pos ] = k;
newValue[ pos ] = value[ i ];
i++;
}
n = newN;
mask = newMask;
maxFill = maxFill( n, f );
this.key = newKey;
this.value = newValue;
this.used = newUsed;
}
/** Returns a deep copy of this map.
*
*
This method performs a deep copy of this hash map; the data stored in the
* map, however, is not cloned. Note that this makes a difference only for object keys.
*
* @return a deep copy of this map.
*/
@SuppressWarnings("unchecked")
public Byte2LongOpenHashMap clone() {
Byte2LongOpenHashMap c;
try {
c = (Byte2LongOpenHashMap )super.clone();
}
catch(CloneNotSupportedException cantHappen) {
throw new InternalError();
}
c.keys = null;
c.values = null;
c.entries = null;
c.key = key.clone();
c.value = value.clone();
c.used = used.clone();
return c;
}
/** Returns a hash code for this map.
*
* 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 map.
*/
public int hashCode() {
int h = 0;
for( int j = size, i = 0, t = 0; j-- != 0; ) {
while( ! used[ i ] ) i++;
t = (key[ i ]);
t ^= it.unimi.dsi.fastutil.HashCommon.long2int(value[ i ]);
h += t;
i++;
}
return h;
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
final byte key[] = this.key;
final long value[] = this.value;
final MapIterator i = new MapIterator();
s.defaultWriteObject();
for( int j = size, e; j-- != 0; ) {
e = i.nextEntry();
s.writeByte( key[ e ] );
s.writeLong( value[ e ] );
}
}
@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 byte key[] = this.key = new byte[ n ];
final long value[] = this.value = new long[ n ];
final boolean used[] = this.used = new boolean[ n ];
byte k;
long v;
for( int i = size, pos = 0; i-- != 0; ) {
k = s.readByte();
v = s.readLong();
pos = ( it.unimi.dsi.fastutil.HashCommon.murmurHash3( (k) ) ) & mask;
while ( used[ pos ] ) pos = ( pos + 1 ) & mask;
used[ pos ] = true;
key[ pos ] = k;
value[ pos ] = v;
}
if ( ASSERTS ) checkTable();
}
private void checkTable() {}
}