org.eclipse.collections.impl.bag.mutable.AbstractHashBag Maven / Gradle / Ivy
/*
* Copyright (c) 2016 Goldman Sachs.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v. 1.0 which accompany this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.eclipse.collections.impl.bag.mutable;
import java.util.Iterator;
import org.eclipse.collections.api.RichIterable;
import org.eclipse.collections.api.bag.Bag;
import org.eclipse.collections.api.bag.MutableBag;
import org.eclipse.collections.api.block.function.Function;
import org.eclipse.collections.api.block.predicate.Predicate;
import org.eclipse.collections.api.block.predicate.Predicate2;
import org.eclipse.collections.api.block.predicate.primitive.IntPredicate;
import org.eclipse.collections.api.block.procedure.Procedure;
import org.eclipse.collections.api.block.procedure.Procedure2;
import org.eclipse.collections.api.block.procedure.primitive.ObjectIntProcedure;
import org.eclipse.collections.api.map.MutableMap;
import org.eclipse.collections.api.map.primitive.MutableObjectIntMap;
import org.eclipse.collections.impl.Counter;
import org.eclipse.collections.impl.block.factory.primitive.IntToIntFunctions;
import org.eclipse.collections.impl.map.mutable.UnifiedMap;
import org.eclipse.collections.impl.multimap.bag.HashBagMultimap;
public abstract class AbstractHashBag extends AbstractMutableBag
{
protected MutableObjectIntMap items;
protected int size;
@Override
public int addOccurrences(T item, int occurrences)
{
if (occurrences < 0)
{
throw new IllegalArgumentException("Cannot add a negative number of occurrences");
}
if (occurrences > 0)
{
int updatedOccurrences = this.items.updateValue(item, 0, IntToIntFunctions.add(occurrences));
this.size += occurrences;
return updatedOccurrences;
}
return this.occurrencesOf(item);
}
@Override
public boolean equals(Object other)
{
if (this == other)
{
return true;
}
if (!(other instanceof Bag))
{
return false;
}
Bag bag = (Bag) other;
if (this.sizeDistinct() != bag.sizeDistinct())
{
return false;
}
return this.items.keyValuesView().allSatisfy(each -> bag.occurrencesOf(each.getOne()) == each.getTwo());
}
@Override
public int hashCode()
{
Counter counter = new Counter();
this.items.forEachKeyValue((item, count) -> counter.add((item == null ? 0 : AbstractHashBag.this.computeHashCode(item)) ^ count));
return counter.getCount();
}
protected abstract int computeHashCode(T item);
@Override
public abstract MutableBag selectByOccurrences(IntPredicate predicate);
@Override
protected RichIterable getKeysView()
{
return this.items.keysView();
}
@Override
public int sizeDistinct()
{
return this.items.size();
}
@Override
public int occurrencesOf(Object item)
{
return this.items.get(item);
}
@Override
public void forEachWithOccurrences(ObjectIntProcedure objectIntProcedure)
{
this.items.forEachKeyValue(objectIntProcedure);
}
@Override
public MutableMap toMapOfItemToCount()
{
MutableMap map = UnifiedMap.newMap(this.items.size());
this.forEachWithOccurrences(map::put);
return map;
}
@Override
public boolean add(T item)
{
this.items.updateValue(item, 0, IntToIntFunctions.increment());
this.size++;
return true;
}
@Override
public boolean remove(Object item)
{
int newValue = this.items.updateValue((T) item, 0, IntToIntFunctions.decrement());
if (newValue <= 0)
{
this.items.removeKey((T) item);
if (newValue == -1)
{
return false;
}
}
this.size--;
return true;
}
@Override
public void clear()
{
this.items.clear();
this.size = 0;
}
@Override
public boolean isEmpty()
{
return this.items.isEmpty();
}
@Override
public void each(Procedure procedure)
{
this.items.forEachKeyValue((key, count) ->
{
for (int i = 0; i < count; i++)
{
procedure.value(key);
}
});
}
@Override
public void forEachWithIndex(ObjectIntProcedure objectIntProcedure)
{
Counter index = new Counter();
this.items.forEachKeyValue((key, count) ->
{
for (int i = 0; i < count; i++)
{
objectIntProcedure.value(key, index.getCount());
index.increment();
}
});
}
@Override
public void forEachWith(Procedure2 procedure, P parameter)
{
this.items.forEachKeyValue((key, count) ->
{
for (int i = 0; i < count; i++)
{
procedure.value(key, parameter);
}
});
}
@Override
public Iterator iterator()
{
return new InternalIterator();
}
@Override
public boolean removeOccurrences(Object item, int occurrences)
{
if (occurrences < 0)
{
throw new IllegalArgumentException("Cannot remove a negative number of occurrences");
}
if (occurrences == 0)
{
return false;
}
int newValue = this.items.updateValue((T) item, 0, IntToIntFunctions.subtract(occurrences));
if (newValue <= 0)
{
this.size -= occurrences + newValue;
this.items.remove(item);
return newValue + occurrences != 0;
}
this.size -= occurrences;
return true;
}
@Override
public boolean setOccurrences(T item, int occurrences)
{
if (occurrences < 0)
{
throw new IllegalArgumentException("Cannot set a negative number of occurrences");
}
int originalOccurrences = this.items.get(item);
if (originalOccurrences == occurrences)
{
return false;
}
if (occurrences == 0)
{
this.items.remove(item);
}
else
{
this.items.put(item, occurrences);
}
this.size -= originalOccurrences - occurrences;
return true;
}
@Override
public boolean removeIf(Predicate predicate)
{
boolean changed = false;
for (Iterator iterator = this.items.keySet().iterator(); iterator.hasNext(); )
{
T key = iterator.next();
if (predicate.accept(key))
{
this.size -= this.items.get(key);
iterator.remove();
changed = true;
}
}
return changed;
}
@Override
public boolean removeIfWith(Predicate2 predicate, P parameter)
{
boolean changed = false;
for (Iterator iterator = this.items.keySet().iterator(); iterator.hasNext(); )
{
T key = iterator.next();
if (predicate.accept(key, parameter))
{
this.size -= this.items.get(key);
iterator.remove();
changed = true;
}
}
return changed;
}
@Override
public boolean removeAllIterable(Iterable iterable)
{
int oldSize = this.size;
if (iterable instanceof Bag)
{
Bag source = (Bag) iterable;
source.forEachWithOccurrences((each, parameter) ->
{
int removed = this.items.removeKeyIfAbsent((T) each, 0);
this.size -= removed;
});
}
else
{
for (Object each : iterable)
{
int removed = this.items.removeKeyIfAbsent((T) each, 0);
this.size -= removed;
}
}
return this.size != oldSize;
}
@Override
public int size()
{
return this.size;
}
@Override
public boolean contains(Object o)
{
return this.items.containsKey(o);
}
@Override
public HashBagMultimap groupBy(Function function)
{
return this.groupBy(function, HashBagMultimap.newMultimap());
}
@Override
public HashBagMultimap groupByEach(Function> function)
{
return this.groupByEach(function, HashBagMultimap.newMultimap());
}
private class InternalIterator implements Iterator
{
private final Iterator iterator = AbstractHashBag.this.items.keySet().iterator();
private T currentItem;
private int occurrences;
private boolean canRemove;
@Override
public boolean hasNext()
{
return this.occurrences > 0 || this.iterator.hasNext();
}
@Override
public T next()
{
if (this.occurrences == 0)
{
this.currentItem = this.iterator.next();
this.occurrences = AbstractHashBag.this.occurrencesOf(this.currentItem);
}
this.occurrences--;
this.canRemove = true;
return this.currentItem;
}
@Override
public void remove()
{
if (!this.canRemove)
{
throw new IllegalStateException();
}
if (this.occurrences == 0)
{
this.iterator.remove();
AbstractHashBag.this.size--;
}
else
{
AbstractHashBag.this.remove(this.currentItem);
}
this.canRemove = false;
}
}
}