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/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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You should have received a copy of the GNU Lesser General Public
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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) */
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/* Static containers (values) */
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/*
* 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.floats;
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;
/**
* 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 {@code 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 FloatLinkedOpenHashSet extends AbstractFloatSortedSet implements java.io.Serializable, Cloneable, Hash {
private static final long serialVersionUID = 0L;
private static final boolean ASSERTS = false;
/** The array of keys. */
protected transient float[] 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. Note that an additional element is allocated for
* storing the null key.
*/
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.
*/
public FloatLinkedOpenHashSet(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 float[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 FloatLinkedOpenHashSet(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 FloatLinkedOpenHashSet() {
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 FloatLinkedOpenHashSet(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 FloatLinkedOpenHashSet(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 FloatLinkedOpenHashSet(final FloatCollection 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 FloatLinkedOpenHashSet(final FloatCollection 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 FloatLinkedOpenHashSet(final FloatIterator i, final float f) {
this(DEFAULT_INITIAL_SIZE, f);
while (i.hasNext())
add(i.nextFloat());
}
/**
* 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 FloatLinkedOpenHashSet(final FloatIterator i) {
this(i, DEFAULT_LOAD_FACTOR);
}
/**
* Creates a new hash set using elements provided by an iterator.
*
* @param i
* an iterator whose elements will fill the set.
* @param f
* the load factor.
*/
public FloatLinkedOpenHashSet(final Iterator i, final float f) {
this(FloatIterators.asFloatIterator(i), f);
}
/**
* Creates a new hash set with {@link Hash#DEFAULT_LOAD_FACTOR} as load
* factor using elements provided by an iterator.
*
* @param i
* an iterator whose elements will fill the set.
*/
public FloatLinkedOpenHashSet(final Iterator i) {
this(FloatIterators.asFloatIterator(i));
}
/**
* 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 FloatLinkedOpenHashSet(final float[] a, final int offset, final int length, final float f) {
this(length < 0 ? 0 : length, f);
FloatArrays.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 FloatLinkedOpenHashSet(final float[] 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 FloatLinkedOpenHashSet(final float[] 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 FloatLinkedOpenHashSet(final float[] 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(FloatCollection c) {
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);
}
/** {@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 float k) {
int pos;
if ((Float.floatToIntBits(k) == 0)) {
if (containsNull) return false;
pos = n;
containsNull = true;
} else {
float curr;
final float[] key = this.key;
// The starting point.
if (!(Float.floatToIntBits(curr = key[pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(k)) & mask]) == 0)) {
if ((Float.floatToIntBits(curr) == Float.floatToIntBits(k))) return false;
while (!(Float.floatToIntBits(curr = key[pos = (pos + 1) & mask]) == 0))
if ((Float.floatToIntBits(curr) == Float.floatToIntBits(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;
float curr;
final float[] key = this.key;
for (;;) {
pos = ((last = pos) + 1) & mask;
for (;;) {
if ((Float.floatToIntBits(curr = key[pos]) == 0)) {
key[last] = (0);
return;
}
slot = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(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;
key[n] = (0);
size--;
fixPointers(n);
if (size < maxFill / 4 && n > DEFAULT_INITIAL_SIZE) rehash(n / 2);
return true;
}
public boolean rem(final float k) {
if ((Float.floatToIntBits(k) == 0)) {
if (containsNull) return removeNullEntry();
return false;
}
float curr;
final float[] key = this.key;
int pos;
// The starting point.
if ((Float.floatToIntBits(curr = key[pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(k)) & mask]) == 0)) return false;
if ((Float.floatToIntBits(k) == Float.floatToIntBits(curr))) return removeEntry(pos);
while (true) {
if ((Float.floatToIntBits(curr = key[pos = (pos + 1) & mask]) == 0)) return false;
if ((Float.floatToIntBits(k) == Float.floatToIntBits(curr))) return removeEntry(pos);
}
}
public boolean contains(final float k) {
if ((Float.floatToIntBits(k) == 0)) return containsNull;
float curr;
final float[] key = this.key;
int pos;
// The starting point.
if ((Float.floatToIntBits(curr = key[pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(k)) & mask]) == 0)) return false;
if ((Float.floatToIntBits(k) == Float.floatToIntBits(curr))) return true;
while (true) {
if ((Float.floatToIntBits(curr = key[pos = (pos + 1) & mask]) == 0)) return false;
if ((Float.floatToIntBits(k) == Float.floatToIntBits(curr))) return true;
}
}
/**
* Removes the first key in iteration order.
*
* @return the first key.
* @throws NoSuchElementException
* is this set is empty.
*/
public float removeFirstFloat() {
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 float k = key[pos];
size--;
if ((Float.floatToIntBits(k) == 0)) {
containsNull = false;
key[n] = (0);
} 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 float removeLastFloat() {
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 float k = key[pos];
size--;
if ((Float.floatToIntBits(k) == 0)) {
containsNull = false;
key[n] = (0);
} 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 float k) {
int pos;
if ((Float.floatToIntBits(k) == 0)) {
if (containsNull) {
moveIndexToFirst(n);
return false;
}
containsNull = true;
pos = n;
} else {
// The starting point.
final float key[] = this.key;
pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(k)) & mask;
// There's always an unused entry. TODO
while (!(Float.floatToIntBits(key[pos]) == 0)) {
if ((Float.floatToIntBits(k) == Float.floatToIntBits(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 float k) {
int pos;
if ((Float.floatToIntBits(k) == 0)) {
if (containsNull) {
moveIndexToLast(n);
return false;
}
containsNull = true;
pos = n;
} else {
// The starting point.
final float key[] = this.key;
pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(k)) & mask;
// There's always an unused entry.
while (!(Float.floatToIntBits(key[pos]) == 0)) {
if ((Float.floatToIntBits(k) == Float.floatToIntBits(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, (0));
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 float firstFloat() {
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 float lastFloat() {
if (size == 0) throw new NoSuchElementException();
return key[last];
}
public FloatSortedSet tailSet(float from) {
throw new UnsupportedOperationException();
}
public FloatSortedSet headSet(float to) {
throw new UnsupportedOperationException();
}
public FloatSortedSet subSet(float from, float to) {
throw new UnsupportedOperationException();
}
public FloatComparator 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 AbstractFloatListIterator {
/**
* 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(float from) {
if ((Float.floatToIntBits(from) == 0)) {
if (FloatLinkedOpenHashSet.this.containsNull) {
next = (int) link[n];
prev = n;
return;
} else throw new NoSuchElementException("The key " + from + " does not belong to this set.");
}
if ((Float.floatToIntBits(key[last]) == Float.floatToIntBits(from))) {
prev = last;
index = size;
return;
}
// The starting point.
final float key[] = FloatLinkedOpenHashSet.this.key;
int pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(from)) & mask;
// There's always an unused entry.
while (!(Float.floatToIntBits(key[pos]) == 0)) {
if ((Float.floatToIntBits(key[pos]) == Float.floatToIntBits(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 float nextFloat() {
if (!hasNext()) throw new NoSuchElementException();
curr = next;
next = (int) link[curr];
prev = curr;
if (index >= 0) index++;
if (ASSERTS) assert curr == n || !(Float.floatToIntBits(key[curr]) == 0) : "Position " + curr + " is not used";
return key[curr];
}
public float previousFloat() {
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) {
FloatLinkedOpenHashSet.this.containsNull = false;
FloatLinkedOpenHashSet.this.key[n] = (0);
} else {
float curr;
final float[] key = FloatLinkedOpenHashSet.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 ((Float.floatToIntBits(curr = key[pos]) == 0)) {
key[last] = (0);
return;
}
slot = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(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 FloatListIterator iterator(float from) {
return new SetIterator(from);
}
public FloatListIterator 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 || size > maxFill(l, f)) 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 (l >= n || size > maxFill(l, f)) 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
*/
protected void rehash(final int newN) {
final float key[] = this.key;
final int mask = newN - 1; // Note that this is used by the hashing
// macro
final float newKey[] = new float[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 ((Float.floatToIntBits(key[i]) == 0)) pos = newN;
else {
pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(key[i])) & mask;
while (!(Float.floatToIntBits(newKey[pos]) == 0))
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.
*/
public FloatLinkedOpenHashSet clone() {
FloatLinkedOpenHashSet c;
try {
c = (FloatLinkedOpenHashSet) 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 ((Float.floatToIntBits(key[i]) == 0))
i++;
h += it.unimi.dsi.fastutil.HashCommon.float2int(key[i]);
i++;
}
// Zero / null have hash zero.
return h;
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
final FloatIterator i = iterator();
s.defaultWriteObject();
for (int j = size; j-- != 0;)
s.writeFloat(i.nextFloat());
}
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 float key[] = this.key = new float[n + 1];
final long link[] = this.link = new long[n + 1];
int prev = -1;
first = last = -1;
float k;
for (int i = size, pos; i-- != 0;) {
k = s.readFloat();
if ((Float.floatToIntBits(k) == 0)) {
pos = n;
containsNull = true;
} else {
if (!(Float.floatToIntBits(key[pos = it.unimi.dsi.fastutil.HashCommon.mix(it.unimi.dsi.fastutil.HashCommon.float2int(k)) & mask]) == 0)) while (!(Float.floatToIntBits(key[pos = (pos + 1) & mask]) == 0))
;
}
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() {
}
}