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/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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You should have received a copy of the GNU Lesser General Public
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/* We do not support C11 . */
/* 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) */
/*
* Copyright (C) 2002-2016 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 static it.unimi.dsi.fastutil.HashCommon.arraySize;
import static it.unimi.dsi.fastutil.HashCommon.maxFill;
import java.util.Map;
import java.util.Arrays;
import java.util.NoSuchElementException;
import it.unimi.dsi.fastutil.objects.ObjectCollection;
import it.unimi.dsi.fastutil.objects.AbstractObjectCollection;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
import it.unimi.dsi.fastutil.objects.AbstractObjectSet;
/**
* 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
* 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.
*
* @see Hash
* @see HashCommon
*/
public class Byte2ObjectOpenHashMap extends AbstractByte2ObjectMap 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 V[] value;
/** The mask for wrapping a position counter. */
protected transient int mask;
/** Whether this set contains the key zero. */
protected transient boolean containsNullKey;
/** 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 key zero, if present). */
protected int size;
/** The acceptable load factor. */
protected final float f;
/** Cached set of entries. */
protected transient FastEntrySet entries;
/** Cached set of keys. */
protected transient ByteSet keys;
/** Cached collection of values. */
protected transient ObjectCollection 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 Byte2ObjectOpenHashMap(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 + 1];
value = (V[]) new Object[n + 1];
}
/**
* 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 Byte2ObjectOpenHashMap(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 Byte2ObjectOpenHashMap() {
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 Byte2ObjectOpenHashMap(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 Byte2ObjectOpenHashMap(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 Byte2ObjectOpenHashMap(final Byte2ObjectMap 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 Byte2ObjectOpenHashMap(final Byte2ObjectMap 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 Byte2ObjectOpenHashMap(final byte[] k, final V[] 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 Byte2ObjectOpenHashMap(final byte[] k, final V[] v) {
this(k, v, DEFAULT_LOAD_FACTOR);
}
private int realSize() {
return containsNullKey ? 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);
}
private V removeEntry(final int pos) {
final V oldValue = value[pos];
value[pos] = null;
size--;
shiftKeys(pos);
if (size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE) rehash(n / 2);
return oldValue;
}
private V removeNullEntry() {
containsNullKey = false;
final V oldValue = value[n];
value[n] = null;
size--;
if (size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE) rehash(n / 2);
return oldValue;
}
/** {@inheritDoc} */
public void putAll(Map m) {
if (f <= .5) ensureCapacity(m.size()); // The resulting map will be
// sized for m.size() elements
else tryCapacity(size() + m.size()); // The resulting map will be
// tentatively sized for size()
// + m.size() elements
super.putAll(m);
}
private int insert(final byte k, final V v) {
int pos;
if (((k) == ((byte) 0))) {
if (containsNullKey) return n;
containsNullKey = true;
pos = n;
} else {
byte curr;
final byte[] key = this.key;
// The starting point.
if (!((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) {
if (((curr) == (k))) return pos;
while (!((curr = key[pos = (pos + 1) & mask]) == ((byte) 0)))
if (((curr) == (k))) return pos;
}
}
key[pos] = k;
value[pos] = v;
if (size++ >= maxFill) rehash(arraySize(size + 1, f));
if (ASSERTS) checkTable();
return -1;
}
public V put(final byte k, final V v) {
final int pos = insert(k, v);
if (pos < 0) return defRetValue;
final V oldValue = value[pos];
value[pos] = v;
return oldValue;
}
/**
* {@inheritDoc}
*
* @deprecated Please use the corresponding type-specific method instead.
*/
@Deprecated
@Override
public V put(final Byte ok, final V ov) {
final V v = (ov);
final int pos = insert(((ok).byteValue()), v);
if (pos < 0) return (this.defRetValue);
final V oldValue = value[pos];
value[pos] = v;
return (oldValue);
}
/**
* 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;
byte curr;
final byte[] key = this.key;
for (;;) {
pos = ((last = pos) + 1) & mask;
for (;;) {
if (((curr = key[pos]) == ((byte) 0))) {
key[last] = ((byte) 0);
value[last] = null;
return;
}
slot = (it.unimi.dsi.fastutil.HashCommon.mix((curr))) & mask;
if (last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos) break;
pos = (pos + 1) & mask;
}
key[last] = curr;
value[last] = value[pos];
}
}
public V remove(final byte k) {
if (((k) == ((byte) 0))) {
if (containsNullKey) return removeNullEntry();
return defRetValue;
}
byte curr;
final byte[] key = this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return defRetValue;
if (((k) == (curr))) return removeEntry(pos);
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return defRetValue;
if (((k) == (curr))) return removeEntry(pos);
}
}
/**
* {@inheritDoc}
*
* @deprecated Please use the corresponding type-specific method instead.
*/
@Deprecated
@Override
public V remove(final Object ok) {
final byte k = ((((Byte) (ok)).byteValue()));
if (((k) == ((byte) 0))) {
if (containsNullKey) return (removeNullEntry());
return (this.defRetValue);
}
byte curr;
final byte[] key = this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return (this.defRetValue);
if (((curr) == (k))) return (removeEntry(pos));
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return (this.defRetValue);
if (((curr) == (k))) return (removeEntry(pos));
}
}
/**
* @deprecated Please use the corresponding type-specific method instead.
*/
@Deprecated
public V get(final Byte ok) {
if (ok == null) return null;
final byte k = ((ok).byteValue());
if (((k) == ((byte) 0))) return containsNullKey ? (value[n]) : (this.defRetValue);
byte curr;
final byte[] key = this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return (this.defRetValue);
if (((k) == (curr))) return (value[pos]);
// There's always an unused entry.
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return (this.defRetValue);
if (((k) == (curr))) return (value[pos]);
}
}
public V get(final byte k) {
if (((k) == ((byte) 0))) return containsNullKey ? value[n] : defRetValue;
byte curr;
final byte[] key = this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return defRetValue;
if (((k) == (curr))) return value[pos];
// There's always an unused entry.
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return defRetValue;
if (((k) == (curr))) return value[pos];
}
}
public boolean containsKey(final byte k) {
if (((k) == ((byte) 0))) return containsNullKey;
byte curr;
final byte[] key = this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return false;
if (((k) == (curr))) return true;
// There's always an unused entry.
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return false;
if (((k) == (curr))) return true;
}
}
public boolean containsValue(final Object v) {
final V value[] = this.value;
final byte key[] = this.key;
if (containsNullKey && ((value[n]) == null ? (v) == null : (value[n]).equals(v))) return true;
for (int i = n; i-- != 0;)
if (!((key[i]) == ((byte) 0)) && ((value[i]) == null ? (v) == null : (value[i]).equals(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;
containsNullKey = false;
Arrays.fill(key, ((byte) 0));
Arrays.fill(value, null);
}
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
*/
final class MapEntry implements Byte2ObjectMap.Entry, Map.Entry {
// The table index this entry refers to, or -1 if this entry has been
// deleted.
int index;
MapEntry(final int index) {
this.index = index;
}
MapEntry() {
}
/**
* {@inheritDoc}
*
* @deprecated Please use the corresponding type-specific method
* instead.
*/
@Deprecated
public Byte getKey() {
return (Byte.valueOf(key[index]));
}
public byte getByteKey() {
return key[index];
}
public V getValue() {
return (value[index]);
}
public V setValue(final V v) {
final V oldValue = value[index];
value[index] = v;
return oldValue;
}
@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]) == null ? ((e.getValue())) == null : (value[index]).equals((e.getValue())));
}
public int hashCode() {
return (key[index]) ^ ((value[index]) == null ? 0 : (value[index]).hashCode());
}
public String toString() {
return key[index] + "=>" + value[index];
}
}
/** An iterator over a hash map. */
private class MapIterator {
/**
* The index of the last entry returned, if positive or zero; initially,
* {@link #n}. If negative, the last entry returned was that of the key
* of index {@code - pos - 1} from the {@link #wrapped} list.
*/
int pos = n;
/**
* The index of the last entry that has been returned (more precisely,
* the value of {@link #pos} if {@link #pos} is positive, or
* {@link Integer#MIN_VALUE} if {@link #pos} is negative). 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 boolean telling us whether we should return the entry with the null
* key.
*/
boolean mustReturnNullKey = Byte2ObjectOpenHashMap.this.containsNullKey;
/**
* A lazily allocated list containing keys of entries that have wrapped
* around the table because of removals.
*/
ByteArrayList wrapped;
public boolean hasNext() {
return c != 0;
}
public int nextEntry() {
if (!hasNext()) throw new NoSuchElementException();
c--;
if (mustReturnNullKey) {
mustReturnNullKey = false;
return last = n;
}
final byte key[] = Byte2ObjectOpenHashMap.this.key;
for (;;) {
if (--pos < 0) {
// We are just enumerating elements from the wrapped list.
last = Integer.MIN_VALUE;
final byte k = wrapped.getByte(-pos - 1);
int p = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask;
while (!((k) == (key[p])))
p = (p + 1) & mask;
return p;
}
if (!((key[pos]) == ((byte) 0))) return last = pos;
}
}
/**
* Shifts left entries with the specified hash code, starting at the
* specified position, and empties the resulting free entry.
*
* @param pos
* a starting position.
*/
private final void shiftKeys(int pos) {
// Shift entries with the same hash.
int last, slot;
byte curr;
final byte[] key = Byte2ObjectOpenHashMap.this.key;
for (;;) {
pos = ((last = pos) + 1) & mask;
for (;;) {
if (((curr = key[pos]) == ((byte) 0))) {
key[last] = ((byte) 0);
value[last] = null;
return;
}
slot = (it.unimi.dsi.fastutil.HashCommon.mix((curr))) & mask;
if (last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos) break;
pos = (pos + 1) & mask;
}
if (pos < last) { // Wrapped entry.
if (wrapped == null) wrapped = new ByteArrayList(2);
wrapped.add(key[pos]);
}
key[last] = curr;
value[last] = value[pos];
}
}
public void remove() {
if (last == -1) throw new IllegalStateException();
if (last == n) {
containsNullKey = false;
value[n] = null;
} else if (pos >= 0) shiftKeys(last);
else {
// We're removing wrapped entries.
Byte2ObjectOpenHashMap.this.remove(wrapped.getByte(-pos - 1));
last = -1; // Note that we must not decrement size
return;
}
size--;
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 Byte2ObjectMap.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> {
private final MapEntry entry = new MapEntry();
public MapEntry next() {
entry.index = nextEntry();
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;
if (e.getKey() == null || !(e.getKey() instanceof Byte)) return false;
final byte k = ((((Byte) (e.getKey())).byteValue()));
final V v = ((V) e.getValue());
if (((k) == ((byte) 0))) return Byte2ObjectOpenHashMap.this.containsNullKey && ((value[n]) == null ? (v) == null : (value[n]).equals(v));
byte curr;
final byte[] key = Byte2ObjectOpenHashMap.this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return false;
if (((k) == (curr))) return ((value[pos]) == null ? (v) == null : (value[pos]).equals(v));
// There's always an unused entry.
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return false;
if (((k) == (curr))) return ((value[pos]) == null ? (v) == null : (value[pos]).equals(v));
}
}
@SuppressWarnings("unchecked")
@Override
public boolean rem(final Object o) {
if (!(o instanceof Map.Entry)) return false;
final Map.Entry e = (Map.Entry) o;
if (e.getKey() == null || !(e.getKey() instanceof Byte)) return false;
final byte k = ((((Byte) (e.getKey())).byteValue()));
final V v = ((V) e.getValue());
if (((k) == ((byte) 0))) {
if (containsNullKey && ((value[n]) == null ? (v) == null : (value[n]).equals(v))) {
removeNullEntry();
return true;
}
return false;
}
byte curr;
final byte[] key = Byte2ObjectOpenHashMap.this.key;
int pos;
// The starting point.
if (((curr = key[pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask]) == ((byte) 0))) return false;
if (((curr) == (k))) {
if (((value[pos]) == null ? (v) == null : (value[pos]).equals(v))) {
removeEntry(pos);
return true;
}
return false;
}
while (true) {
if (((curr = key[pos = (pos + 1) & mask]) == ((byte) 0))) return false;
if (((curr) == (k))) {
if (((value[pos]) == null ? (v) == null : (value[pos]).equals(v))) {
removeEntry(pos);
return true;
}
}
}
}
public int size() {
return size;
}
public void clear() {
Byte2ObjectOpenHashMap.this.clear();
}
}
public FastEntrySet byte2ObjectEntrySet() {
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 rem(byte k) {
final int oldSize = size;
Byte2ObjectOpenHashMap.this.remove(k);
return size != oldSize;
}
public void clear() {
Byte2ObjectOpenHashMap.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 ObjectIterator {
public ValueIterator() {
super();
}
public V next() {
return value[nextEntry()];
}
}
public ObjectCollection values() {
if (values == null) values = new AbstractObjectCollection() {
public ObjectIterator iterator() {
return new ValueIterator();
}
public int size() {
return size;
}
public boolean contains(Object v) {
return containsValue(v);
}
public void clear() {
Byte2ObjectOpenHashMap.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 || size > maxFill(l, f)) 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 (l >= n || size > maxFill(l, f)) 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) {
final byte key[] = this.key;
final V value[] = this.value;
final int mask = newN - 1; // Note that this is used by the hashing
// macro
final byte newKey[] = new byte[newN + 1];
final V newValue[] = (V[]) new Object[newN + 1];
int i = n, pos;
for (int j = realSize(); j-- != 0;) {
while (((key[--i]) == ((byte) 0)))
;
if (!((newKey[pos = (it.unimi.dsi.fastutil.HashCommon.mix((key[i]))) & mask]) == ((byte) 0))) while (!((newKey[pos = (pos + 1) & mask]) == ((byte) 0)))
;
newKey[pos] = key[i];
newValue[pos] = value[i];
}
newValue[newN] = value[n];
n = newN;
this.mask = mask;
maxFill = maxFill(n, f);
this.key = newKey;
this.value = newValue;
}
/**
* 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 Byte2ObjectOpenHashMap clone() {
Byte2ObjectOpenHashMap c;
try {
c = (Byte2ObjectOpenHashMap) super.clone();
} catch (CloneNotSupportedException cantHappen) {
throw new InternalError();
}
c.keys = null;
c.values = null;
c.entries = null;
c.containsNullKey = containsNullKey;
c.key = key.clone();
c.value = value.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 = realSize(), i = 0, t = 0; j-- != 0;) {
while (((key[i]) == ((byte) 0)))
i++;
t = (key[i]);
if (this != value[i]) t ^= ((value[i]) == null ? 0 : (value[i]).hashCode());
h += t;
i++;
}
// Zero / null keys have hash zero.
if (containsNullKey) h += ((value[n]) == null ? 0 : (value[n]).hashCode());
return h;
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
final byte key[] = this.key;
final V 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.writeObject(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 + 1];
final V value[] = this.value = (V[]) new Object[n + 1];
byte k;
V v;
for (int i = size, pos; i-- != 0;) {
k = s.readByte();
v = (V) s.readObject();
if (((k) == ((byte) 0))) {
pos = n;
containsNullKey = true;
} else {
pos = (it.unimi.dsi.fastutil.HashCommon.mix((k))) & mask;
while (!((key[pos]) == ((byte) 0)))
pos = (pos + 1) & mask;
}
key[pos] = k;
value[pos] = v;
}
if (ASSERTS) checkTable();
}
private void checkTable() {
}
}