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/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/*
Copyright � 1999 CERN - European Organization for Nuclear Research.
Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose
is hereby granted without fee, provided that the above copyright notice appear in all copies and
that both that copyright notice and this permission notice appear in supporting documentation.
CERN makes no representations about the suitability of this software for any purpose.
It is provided "as is" without expressed or implied warranty.
*/
package org.apache.mahout.math.map;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.mahout.math.Sorting;
import org.apache.mahout.math.Swapper;
import org.apache.mahout.math.function.ObjectShortProcedure;
import org.apache.mahout.math.function.ObjectProcedure;
import org.apache.mahout.math.list.ShortArrayList;
import org.apache.mahout.math.function.IntComparator;
import org.apache.mahout.math.set.AbstractSet;
public abstract class AbstractObjectShortMap extends AbstractSet {
/**
* Returns true if the receiver contains the specified key.
*
* @return true if the receiver contains the specified key.
*/
public boolean containsKey(final T key) {
return !forEachKey(
new ObjectProcedure() {
@Override
public boolean apply(T iterKey) {
return (key != iterKey);
}
}
);
}
/**
* Returns true if the receiver contains the specified value.
*
* @return true if the receiver contains the specified value.
*/
public boolean containsValue(final short value) {
return !forEachPair(
new ObjectShortProcedure() {
@Override
public boolean apply(T iterKey, short iterValue) {
return (value != iterValue);
}
}
);
}
/**
* Returns a deep copy of the receiver; uses clone() and casts the result.
*
* @return a deep copy of the receiver.
*/
@SuppressWarnings("unchecked") // seemingly unavoidable.
public AbstractObjectShortMap copy() {
return (AbstractObjectShortMap) clone();
}
/**
* Compares the specified object with this map for equality. Returns true if the given object is also a map
* and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the
* same mappings iff
*
* m1.forEachPair(
* new ObjectShortProcedure() {
* public boolean apply(T key, short value) {
* return m2.containsKey(key) && m2.get(key) == value;
* }
* }
* )
* &&
* m2.forEachPair(
* new ObjectShortProcedure() {
* public boolean apply(T key, short value) {
* return m1.containsKey(key) && m1.get(key) == value;
* }
* }
* );
*
*
* This implementation first checks if the specified object is this map; if so it returns true. Then, it
* checks if the specified object is a map whose size is identical to the size of this set; if not, it it returns
* false. If so, it applies the iteration as described above.
*
* @param obj object to be compared for equality with this map.
* @return true if the specified object is equal to this map.
*/
@SuppressWarnings("unchecked")
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof AbstractObjectShortMap)) {
return false;
}
final AbstractObjectShortMap other = (AbstractObjectShortMap) obj;
if (other.size() != size()) {
return false;
}
return
forEachPair(
new ObjectShortProcedure() {
@Override
public boolean apply(T key, short value) {
return other.containsKey(key) && other.get(key) == value;
}
}
)
&&
other.forEachPair(
new ObjectShortProcedure() {
@Override
public boolean apply(T key, short value) {
return containsKey(key) && get(key) == value;
}
}
);
}
/**
* Applies a procedure to each key of the receiver, if any. Note: Iterates over the keys in no particular order.
* Subclasses can define a particular order, for example, "sorted by key". All methods which can be expressed
* in terms of this method (most methods can) must guarantee to use the same order defined by this
* method, even if it is no particular order. This is necessary so that, for example, methods keys and
* values will yield association pairs, not two uncorrelated lists.
*
* @param procedure the procedure to be applied. Stops iteration if the procedure returns false, otherwise
* continues.
* @return false if the procedure stopped before all keys where iterated over, true otherwise.
*/
public abstract boolean forEachKey(ObjectProcedure procedure);
/**
* Applies a procedure to each (key,value) pair of the receiver, if any. Iteration order is guaranteed to be
* identical to the order used by method {@link #forEachKey(ObjectProcedure)}.
*
* @param procedure the procedure to be applied. Stops iteration if the procedure returns false, otherwise
* continues.
* @return false if the procedure stopped before all keys where iterated over, true otherwise.
*/
public boolean forEachPair(final ObjectShortProcedure procedure) {
return forEachKey(
new ObjectProcedure() {
@Override
public boolean apply(T key) {
return procedure.apply(key, get(key));
}
}
);
}
/**
* Returns the value associated with the specified key. It is often a good idea to first check with {@link
* #containsKey(Object)} whether the given key has a value associated or not, i.e. whether there exists an association
* for the given key or not.
*
* @param key the key to be searched for.
* @return the value associated with the specified key; 0 if no such key is present.
*/
public abstract short get(T key);
/**
* Returns a list filled with all keys contained in the receiver. The returned list has a size that equals
* this.size(). Iteration order is guaranteed to be identical to the order used by method {@link
* #forEachKey(ObjectProcedure)}. This method can be used to iterate over the keys of the receiver.
*
* @return the keys.
*/
public List keys() {
List list = new ArrayList(size());
keys(list);
return list;
}
/**
* Fills all keys contained in the receiver into the specified list. Fills the list, starting at index 0. After this
* call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to
* be identical to the order used by method {@link #forEachKey(ObjectProcedure)}. This method can be used to
* iterate over the keys of the receiver.
*
* @param list the list to be filled, can have any size.
*/
public void keys(final List list) {
list.clear();
forEachKey(
new ObjectProcedure() {
@Override
public boolean apply(T key) {
list.add(key);
return true;
}
}
);
}
/**
* Fills all keys sorted ascending by their associated value into the specified list. Fills into the list,
* starting at index 0. After this call returns the specified list has a new size that equals this.size().
* Primary sort criterium is "value", secondary sort criterium is "key". This means that if any two values are equal,
* the smaller key comes first. Example:
keys = (8,7,6), values = (1,2,2) --> keyList =
* (8,6,7)
*
* @param keyList the list to be filled, can have any size.
*/
public void keysSortedByValue(List keyList) {
pairsSortedByValue(keyList, new ShortArrayList(size()));
}
/**
* Fills all pairs satisfying a given condition into the specified lists. Fills into the lists, starting at index 0.
* After this call returns the specified lists both have a new size, the number of pairs satisfying the condition.
* Iteration order is guaranteed to be identical to the order used by method
* {@link #forEachKey(ObjectProcedure)}.
* Example:
*
* IntIntProcedure condition = new IntIntProcedure() { // match even keys only
* public boolean apply(int key, int value) { return key%2==0; }
* }
* keys = (8,7,6), values = (1,2,2) --> keyList = (6,8), valueList = (2,1)
*
*
* @param condition the condition to be matched. Takes the current key as first and the current value as second
* argument.
* @param keyList the list to be filled with keys, can have any size.
* @param valueList the list to be filled with values, can have any size.
*/
public void pairsMatching(final ObjectShortProcedure condition,
final List keyList,
final ShortArrayList valueList) {
keyList.clear();
valueList.clear();
forEachPair(
new ObjectShortProcedure() {
@Override
public boolean apply(T key, short value) {
if (condition.apply(key, value)) {
keyList.add(key);
valueList.add(value);
}
return true;
}
}
);
}
/**
* Fills all keys and values sorted ascending by key into the specified lists. Fills into the lists, starting
* at index 0. After this call returns the specified lists both have a new size that equals this.size().
* Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (6,7,8), valueList = (2,2,1)
*
* @param keyList the list to be filled with keys, can have any size.
* @param valueList the list to be filled with values, can have any size.
*/
@SuppressWarnings("unchecked")
public void pairsSortedByKey(List keyList, ShortArrayList valueList) {
keys(keyList);
if (keyList.isEmpty()) {
return;
}
T k = keyList.get(0);
// some people would demand a more complex type hierarchy here ...
if (!(k instanceof Comparable)) {
throw new UnsupportedOperationException("The key type for this map does not implement comparable");
}
Collections.sort((List) keyList);
valueList.setSize(keyList.size());
for (int i = keyList.size(); --i >= 0;) {
valueList.setQuick(i, get(keyList.get(i)));
}
}
/**
* Fills all keys and values sorted ascending by value into the specified lists. Fills into the lists, starting
* at index 0. After this call returns the specified lists both have a new size that equals this.size().
* Primary sort criterium is "value", secondary sort criterium is "key". This means that if any two values are equal,
* the smaller key comes first. Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (8,6,7),
* valueList = (1,2,2)
*
* @param keyList the list to be filled with keys, can have any size.
* @param valueList the list to be filled with values, can have any size.
*/
public void pairsSortedByValue(final List keyList, ShortArrayList valueList) {
keys(keyList);
values(valueList);
final short[] v = valueList.elements();
Swapper swapper = new Swapper() {
@Override
public void swap(int a, int b) {
short t1 = v[a];
v[a] = v[b];
v[b] = t1;
T t2 = keyList.get(a);
keyList.set(a, keyList.get(b));
keyList.set(b, t2);
}
};
IntComparator comp = new IntComparator() {
@Override
public int compare(int a, int b) {
return v[a] < v[b] ? -1 : v[a] > v[b] ? 1 : 0;
}
};
Sorting.quickSort(0, keyList.size(), comp, swapper);
}
/**
* Associates the given key with the given value. Replaces any old (key,someOtherValue) association, if
* existing.
*
* @param key the key the value shall be associated with.
* @param value the value to be associated.
* @return true if the receiver did not already contain such a key; false if the receiver did
* already contain such a key - the new value has now replaced the formerly associated value.
*/
public abstract boolean put(T key, short value);
/**
* Removes the given key with its associated element from the receiver, if present.
*
* @param key the key to be removed from the receiver.
* @return true if the receiver contained the specified key, false otherwise.
*/
public abstract boolean removeKey(T key);
/**
* Returns a string representation of the receiver, containing the String representation of each key-value pair,
* sorted ascending by key.
*/
public String toString() {
List theKeys = keys();
StringBuilder buf = new StringBuilder();
buf.append('[');
int maxIndex = theKeys.size() - 1;
for (int i = 0; i <= maxIndex; i++) {
T key = theKeys.get(i);
buf.append(String.valueOf(key));
buf.append("->");
buf.append(String.valueOf(get(key)));
if (i < maxIndex) {
buf.append(", ");
}
}
buf.append(']');
return buf.toString();
}
/**
* Returns a string representation of the receiver, containing the String representation of each key-value pair,
* sorted ascending by value.
*/
public String toStringByValue() {
List theKeys = new ArrayList();
keysSortedByValue(theKeys);
StringBuilder buf = new StringBuilder();
buf.append('[');
int maxIndex = theKeys.size() - 1;
for (int i = 0; i <= maxIndex; i++) {
T key = theKeys.get(i);
buf.append(String.valueOf(key));
buf.append("->");
buf.append(String.valueOf(get(key)));
if (i < maxIndex) {
buf.append(", ");
}
}
buf.append(']');
return buf.toString();
}
/**
* Returns a list filled with all values contained in the receiver. The returned list has a size that equals
* this.size(). Iteration order is guaranteed to be identical to the order used by method {@link
* #forEachKey(ObjectProcedure)}. This method can be used to iterate over the values of the receiver.
*
* @return the values.
*/
public ShortArrayList values() {
ShortArrayList list = new ShortArrayList(size());
values(list);
return list;
}
/**
* Fills all values contained in the receiver into the specified list. Fills the list, starting at index 0. After this
* call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to
* be identical to the order used by method {@link #forEachKey(ObjectProcedure)}.
This method can be used to
* iterate over the values of the receiver.
*
* @param list the list to be filled, can have any size.
*/
public void values(final ShortArrayList list) {
list.clear();
forEachKey(
new ObjectProcedure() {
@Override
public boolean apply(T key) {
list.add(get(key));
return true;
}
}
);
}
/**
* Check the map for a key. If present, add an increment to the value. If absent,
* store a specified value.
* @param key the key.
* @param newValue the value to store if the key is not currently in the map.
* @param incrValue the value to be added to the current value in the map.
**/
public short adjustOrPutValue(T key, short newValue, short incrValue) {
boolean present = containsKey(key);
if (present) {
newValue = (short)(get(key) + incrValue);
put(key, newValue);
} else {
put(key, newValue);
}
return newValue;
}
}