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fastutil extends the Java Collections Framework by providing type-specific maps, sets, lists and priority queues with a small memory footprint and fast access and insertion; provides also big (64-bit) arrays, sets and lists, and fast, practical I/O classes for binary and text files.

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/*
	* Copyright (C) 2002-2017 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.ints;
import it.unimi.dsi.fastutil.ints.IntCollection;
import it.unimi.dsi.fastutil.objects.ObjectSet;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
import java.util.function.Consumer;
import java.util.Map;
/**
 * A type-specific {@link Map}; provides some additional methods that use
 * polymorphism to avoid (un)boxing, and handling of a default return value.
 *
 * 

* Besides extending the corresponding type-specific * {@linkplain it.unimi.dsi.fastutil.Function function}, this interface * strengthens {@link Map#entrySet()}, {@link #keySet()} and {@link #values()}. * Moreover, a number of methods, such as {@link #size()}, * {@link #defaultReturnValue()}, etc., are un-defaulted as their function * default do not make sense for a map. Maps returning entry sets of type * {@link FastEntrySet} support also fast iteration. * *

* A submap or subset may or may not have an independent default return value * (which however must be initialized to the default return value of the * originator). * * @see Map */ public interface Int2IntMap extends Int2IntFunction, Map { /** * An entry set providing fast iteration. * *

* In some cases (e.g., hash-based classes) iteration over an entry set requires * the creation of a large number of {@link java.util.Map.Entry} objects. Some * {@code fastutil} maps might return {@linkplain Map#entrySet() entry set} * objects of type {@code FastEntrySet}: in this case, {@link #fastIterator() * fastIterator()} will return an iterator that is guaranteed not to create a * large number of objects, possibly by returning always the same entry * (of course, mutated), and {@link #fastForEach(Consumer)} will apply the * provided consumer to all elements of the entry set, which might be * represented always by the same entry (of course, mutated). */ interface FastEntrySet extends ObjectSet { /** * Returns a fast iterator over this entry set; the iterator might return always * the same entry instance, suitably mutated. * * @return a fast iterator over this entry set; the iterator might return always * the same {@link java.util.Map.Entry} instance, suitably mutated. */ ObjectIterator fastIterator(); /** * Iterates quickly over this entry set; the iteration might happen always on * the same entry instance, suitably mutated. * *

* This default implementation just delegates to {@link #forEach(Consumer)}. * * @param consumer * a consumer that will by applied to the entries of this set; the * entries might be represented by the same entry instance, suitably * mutated. * @since 8.1.0 */ default void fastForEach(final Consumer consumer) { forEach(consumer); } } /** * Returns the number of key/value mappings in this map. If the map contains * more than {@link Integer#MAX_VALUE} elements, returns * {@link Integer#MAX_VALUE}. * * @return the number of key-value mappings in this map. * @see it.unimi.dsi.fastutil.Size64 */ @Override int size(); /** * Removes all of the mappings from this map (optional operation). The map will * be empty after this call returns. * * @throws UnsupportedOperationException * if the clear operation is not supported by this map */ @Override default void clear() { throw new UnsupportedOperationException(); } /** * Sets the default return value (optional operation). * * This value must be returned by type-specific versions of {@code get()}, * {@code put()} and {@code remove()} to denote that the map does not contain * the specified key. It must be 0/{@code false} by default. * * @param rv * the new default return value. * @see #defaultReturnValue() */ @Override void defaultReturnValue(int rv); /** * Gets the default return value. * * @return the current default return value. */ @Override int defaultReturnValue(); /** * Returns a type-specific set view of the mappings contained in this map. * *

* This method is necessary because there is no inheritance along type * parameters: it is thus impossible to strengthen {@link Map#entrySet()} so * that it returns an {@link it.unimi.dsi.fastutil.objects.ObjectSet} of * type-specific entries (the latter makes it possible to access keys and values * with type-specific methods). * * @return a type-specific set view of the mappings contained in this map. * @see Map#entrySet() */ ObjectSet int2IntEntrySet(); /** * Returns a set view of the mappings contained in this map. *

* Note that this specification strengthens the one given in * {@link Map#entrySet()}. * * @return a set view of the mappings contained in this map. * @see Map#entrySet() * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override @SuppressWarnings({"unchecked", "rawtypes"}) default ObjectSet> entrySet() { return (ObjectSet) int2IntEntrySet(); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding * type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer put(final Integer key, final Integer value) { return Int2IntFunction.super.put(key, value); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding * type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer get(final Object key) { return Int2IntFunction.super.get(key); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding * type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer remove(final Object key) { return Int2IntFunction.super.remove(key); } /** * {@inheritDoc} *

* Note that this specification strengthens the one given in * {@link Map#keySet()}. * * @return a set view of the keys contained in this map. * @see Map#keySet() */ @Override IntSet keySet(); /** * {@inheritDoc} *

* Note that this specification strengthens the one given in * {@link Map#values()}. * * @return a set view of the values contained in this map. * @see Map#values() */ @Override IntCollection values(); /** * Returns true if this function contains a mapping for the specified key. * * @param key * the key. * @return true if this function associates a value to {@code key}. * @see Map#containsKey(Object) */ @Override boolean containsKey(int key); /** * Returns true if this function contains a mapping for the specified key. *

* This default implementation just delegates to the corresponding * type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default boolean containsKey(final Object key) { return Int2IntFunction.super.containsKey(key); } /** * Returns {@code true} if this map maps one or more keys to the specified * value. * * @see Map#containsValue(Object) */ boolean containsValue(int value); /** * {@inheritDoc} * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default boolean containsValue(final Object value) { return value == null ? false : containsValue(((Integer) (value)).intValue()); } // Defaultable methods /** * Returns the value to which the specified key is mapped, or the * {@code defaultValue} if this map contains no mapping for the key. * * @param key * the key. * @param defaultValue * the default mapping of the key. * * @return the value to which the specified key is mapped, or the * {@code defaultValue} if this map contains no mapping for the key. * * @see java.util.Map#getOrDefault(Object, Object) * @since 8.0.0 */ default int getOrDefault(final int key, final int defaultValue) { final int v; return ((v = get(key)) != defaultReturnValue() || containsKey(key)) ? v : defaultValue; } /** * If the specified key is not already associated with a value, associates it * with the given value and returns the {@linkplain #defaultReturnValue() * default return value}, else returns the current value. * * @param key * key with which the specified value is to be associated. * @param value * value to be associated with the specified key. * * @return the previous value associated with the specified key, or the * {@linkplain #defaultReturnValue() default return value} if there was * no mapping for the key. * * @see java.util.Map#putIfAbsent(Object, Object) * @since 8.0.0 */ default int putIfAbsent(final int key, final int value) { final int v = get(key), drv = defaultReturnValue(); if (v != drv || containsKey(key)) return v; put(key, value); return drv; } /** * Removes the entry for the specified key only if it is currently mapped to the * specified value. * * @param key * key with which the specified value is associated. * @param value * value expected to be associated with the specified key. * * @return {@code true} if the value was removed. * * @see java.util.Map#remove(Object, Object) * @since 8.0.0 */ default boolean remove(final int key, final int value) { final int curValue = get(key); if (!((curValue) == (value)) || (curValue == defaultReturnValue() && !containsKey(key))) return false; remove(key); return true; } /** * Replaces the entry for the specified key only if currently mapped to the * specified value. * * @param key * key with which the specified value is associated. * @param oldValue * value expected to be associated with the specified key. * @param newValue * value to be associated with the specified key. * * @return {@code true} if the value was replaced. * * @see java.util.Map#replace(Object, Object, Object) * @since 8.0.0 */ default boolean replace(final int key, final int oldValue, final int newValue) { final int curValue = get(key); if (!((curValue) == (oldValue)) || (curValue == defaultReturnValue() && !containsKey(key))) return false; put(key, newValue); return true; } /** * Replaces the entry for the specified key only if it is currently mapped to * some value. * * @param key * key with which the specified value is associated. * @param value * value to be associated with the specified key. * * @return the previous value associated with the specified key, or the * {@linkplain #defaultReturnValue() default return value} if there was * no mapping for the key. * * @see java.util.Map#replace(Object, Object) * @since 8.0.0 */ default int replace(final int key, final int value) { return containsKey(key) ? put(key, value) : defaultReturnValue(); } /** * If the specified key is not already associated with a value, attempts to * compute its value using the given mapping function and enters it into this * map. * *

* Note that contrarily to the default * {@linkplain java.util.Map#computeIfAbsent(Object, java.util.function.Function) * computeIfAbsent()}, it is not possible to not add a value for a given key, * since the {@code mappingFunction} cannot return {@code null}. If such a * behavior is needed, please use the corresponding nullable version. * * @param key * key with which the specified value is to be associated. * @param mappingFunction * the function to compute a value. * * @return the current (existing or computed) value associated with the * specified key. * * @see java.util.Map#computeIfAbsent(Object, java.util.function.Function) * @since 8.0.0 */ default int computeIfAbsent(final int key, final java.util.function.IntUnaryOperator mappingFunction) { java.util.Objects.requireNonNull(mappingFunction); final int v = get(key); if (v != defaultReturnValue() || containsKey(key)) return v; int newValue = mappingFunction.applyAsInt(key); put(key, newValue); return newValue; } /** * If the specified key is not already associated with a value, attempts to * compute its value using the given mapping function and enters it into this * map unless it is {@code null}. * *

* Note that this version of * {@linkplain java.util.Map#computeIfAbsent(Object, java.util.function.Function) * computeIfAbsent()} should be used only if you plan to return {@code null} in * the mapping function. * * @param key * key with which the specified value is to be associated. * @param mappingFunction * the function to compute a value. * * @return the current (existing or computed) value associated with the * specified key, or the {@linkplain #defaultReturnValue() default * return value} if the computed value is {@code null}. * * @see java.util.Map#computeIfAbsent(Object, java.util.function.Function) * @since 8.0.0 */ default int computeIfAbsentNullable(final int key, final java.util.function.IntFunction mappingFunction) { java.util.Objects.requireNonNull(mappingFunction); final int v = get(key), drv = defaultReturnValue(); if (v != drv || containsKey(key)) return v; Integer mappedValue = mappingFunction.apply(key); if (mappedValue == null) return drv; int newValue = (mappedValue).intValue(); put(key, newValue); return newValue; } /** * If the specified key is not already associated with a value, attempts to * compute its value using the given mapping function and enters it into this * map, unless the key is not present in the given mapping function. * *

* This version of * {@linkplain java.util.Map#computeIfAbsent(Object, java.util.function.Function) * computeIfAbsent()} uses a type-specific version of fastutil's * {@link it.unimi.dsi.fastutil.Function Function}. Since * {@link it.unimi.dsi.fastutil.Function Function} has a * {@link it.unimi.dsi.fastutil.Function#containsKey(Object) containsKey()} * method, it is possible to avoid adding a key by having {@code containsKey()} * return {@code false} for that key. * * @param key * key with which the specified value is to be associated. * @param mappingFunction * the function to compute a value. * * @return the current (existing or computed) value associated with the * specified key. * * @see java.util.Map#computeIfAbsent(Object, java.util.function.Function) * @since 8.0.0 */ default int computeIfAbsentPartial(final int key, final Int2IntFunction mappingFunction) { java.util.Objects.requireNonNull(mappingFunction); final int v = get(key), drv = defaultReturnValue(); if (v != drv || containsKey(key)) return v; if (!mappingFunction.containsKey(key)) return drv; int newValue = mappingFunction.get(key); put(key, newValue); return newValue; } /** * If the value for the specified key is present, attempts to compute a new * mapping given the key and its current mapped value. * * @param key * key with which the specified value is to be associated. * @param remappingFunction * the function to compute a value. * * @return the new value associated with the specified key, or the * {@linkplain #defaultReturnValue() default return value} if none. * * @see java.util.Map#computeIfPresent(Object, java.util.function.BiFunction) * @since 8.0.0 */ default int computeIfPresent(final int key, final java.util.function.BiFunction remappingFunction) { java.util.Objects.requireNonNull(remappingFunction); final int oldValue = get(key), drv = defaultReturnValue(); if (oldValue == drv && !containsKey(key)) return drv; final Integer newValue = remappingFunction.apply(Integer.valueOf(key), Integer.valueOf(oldValue)); if (newValue == null) { remove(key); return drv; } int newVal = (newValue).intValue(); put(key, newVal); return newVal; } /** * Attempts to compute a mapping for the specified key and its current mapped * value (or {@code null} if there is no current mapping). * *

* If the function returns {@code null}, the mapping is removed (or remains * absent if initially absent). If the function itself throws an (unchecked) * exception, the exception is rethrown, and the current mapping is left * unchanged. * * @param key * key with which the specified value is to be associated. * @param remappingFunction * the function to compute a value. * * @return the new value associated with the specified key, or the * {@linkplain #defaultReturnValue() default return value} if none. * * @see java.util.Map#compute(Object, java.util.function.BiFunction) * @since 8.0.0 */ default int compute(final int key, final java.util.function.BiFunction remappingFunction) { java.util.Objects.requireNonNull(remappingFunction); final int oldValue = get(key), drv = defaultReturnValue(); final boolean contained = oldValue != drv || containsKey(key); final Integer newValue = remappingFunction.apply(Integer.valueOf(key), contained ? Integer.valueOf(oldValue) : null); if (newValue == null) { if (contained) remove(key); return drv; } final int newVal = (newValue).intValue(); put(key, newVal); return newVal; } /** * If the specified key is not already associated with a value, associates it * with the given {@code value}. Otherwise, replaces the associated value with * the results of the given remapping function, or removes if the result is * {@code null}. * * @param key * key with which the resulting value is to be associated. * @param value * the value to be merged with the existing value associated with the * key or, if no existing value is associated with the key, to be * associated with the key. * @param remappingFunction * the function to recompute a value if present. * * @return the new value associated with the specified key, or the * {@linkplain #defaultReturnValue() default return value} if no value * is associated with the key. * * @see java.util.Map#merge(Object, Object, java.util.function.BiFunction) * @since 8.0.0 */ default int merge(final int key, final int value, final java.util.function.BiFunction remappingFunction) { java.util.Objects.requireNonNull(remappingFunction); final int oldValue = get(key), drv = defaultReturnValue(); final int newValue; if (oldValue != drv || containsKey(key)) { final Integer mergedValue = remappingFunction.apply(Integer.valueOf(oldValue), Integer.valueOf(value)); if (mergedValue == null) { remove(key); return drv; } newValue = (mergedValue).intValue(); } else { newValue = value; } put(key, newValue); return newValue; } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer getOrDefault(final Object key, final Integer defaultValue) { return Map.super.getOrDefault(key, defaultValue); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer putIfAbsent(final Integer key, final Integer value) { return Map.super.putIfAbsent(key, value); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default boolean remove(final Object key, final Object value) { return Map.super.remove(key, value); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default boolean replace(final Integer key, final Integer oldValue, final Integer newValue) { return Map.super.replace(key, oldValue, newValue); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer replace(final Integer key, final Integer value) { return Map.super.replace(key, value); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer computeIfAbsent(final Integer key, final java.util.function.Function mappingFunction) { return Map.super.computeIfAbsent(key, mappingFunction); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer computeIfPresent(final Integer key, final java.util.function.BiFunction remappingFunction) { return Map.super.computeIfPresent(key, remappingFunction); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer compute(final Integer key, final java.util.function.BiFunction remappingFunction) { return Map.super.compute(key, remappingFunction); } /** * {@inheritDoc} *

* This default implementation just delegates to the corresponding {@link Map} * method. * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer merge(final Integer key, final Integer value, final java.util.function.BiFunction remappingFunction) { return Map.super.merge(key, value, remappingFunction); } /** * A type-specific {@link java.util.Map.Entry}; provides some additional methods * that use polymorphism to avoid (un)boxing. * * @see java.util.Map.Entry */ interface Entry extends Map.Entry { /** * Returns the key corresponding to this entry. * * @see java.util.Map.Entry#getKey() */ int getIntKey(); /** * {@inheritDoc} * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer getKey() { return Integer.valueOf(getIntKey()); } /** * Returns the value corresponding to this entry. * * @see java.util.Map.Entry#getValue() */ int getIntValue(); /** * Replaces the value corresponding to this entry with the specified value * (optional operation). * * @see java.util.Map.Entry#setValue(Object) */ int setValue(final int value); /** * {@inheritDoc} * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer getValue() { return Integer.valueOf(getIntValue()); } /** * {@inheritDoc} * * @deprecated Please use the corresponding type-specific method instead. */ @Deprecated @Override default Integer setValue(final Integer value) { return Integer.valueOf(setValue((value).intValue())); } } }





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