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A fork of the Apache Cassandra Project ready to embed Elasticsearch.
/*
* 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.
*/
package org.apache.cassandra.dht;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Set;
import com.google.common.collect.Iterators;
import com.google.common.collect.Lists;
import com.google.common.collect.PeekingIterator;
import com.google.common.collect.Sets;
import org.apache.cassandra.db.PartitionPosition;
import org.apache.cassandra.utils.Pair;
/**
* AbstractBounds containing both its endpoints: [left, right]. Used by "classic" by-key range scans.
*/
public class Bounds> extends AbstractBounds
{
public Bounds(T left, T right)
{
super(left, right);
// unlike a Range, a Bounds may not wrap
assert !strictlyWrapsAround(left, right) : "[" + left + "," + right + "]";
}
public boolean contains(T position)
{
// Range.contains doesnt work correctly if left == right (unless both
// are minimum) because for Range that means a wrapping range that select
// the whole ring. So we must explicitely handle this case
return left.equals(position) || ((right.isMinimum() || !left.equals(right)) && Range.contains(left, right, position));
}
public Pair, AbstractBounds> split(T position)
{
assert contains(position);
// Check if the split would have no effect on the range
if (position.equals(right))
return null;
AbstractBounds lb = new Bounds(left, position);
AbstractBounds rb = new Range(position, right);
return Pair.create(lb, rb);
}
public boolean inclusiveLeft()
{
return true;
}
public boolean inclusiveRight()
{
return true;
}
public boolean intersects(Bounds that)
{
// We either contains one of the that bounds, or we are fully contained into that.
return contains(that.left) || contains(that.right) || that.contains(left);
}
public List> unwrap()
{
// Bounds objects never wrap
return Collections.>singletonList(this);
}
@Override
public boolean equals(Object o)
{
if (!(o instanceof Bounds))
return false;
Bounds rhs = (Bounds)o;
return left.equals(rhs.left) && right.equals(rhs.right);
}
@Override
public String toString()
{
return "[" + left + "," + right + "]";
}
protected String getOpeningString()
{
return "[";
}
protected String getClosingString()
{
return "]";
}
public static > boolean isInBounds(T token, Iterable> bounds)
{
assert bounds != null;
for (Bounds bound : bounds)
{
if (bound.contains(token))
{
return true;
}
}
return false;
}
public boolean isStartInclusive()
{
return true;
}
public boolean isEndInclusive()
{
return true;
}
/**
* Compute a bounds of keys corresponding to a given bounds of token.
*/
public static Bounds makeRowBounds(Token left, Token right)
{
return new Bounds(left.minKeyBound(), right.maxKeyBound());
}
public AbstractBounds withNewRight(T newRight)
{
return new Bounds(left, newRight);
}
/**
* Retrieves non-overlapping bounds for the list of input bounds
*
* Assume we have the following bounds
* (brackets representing left/right bound):
* [ ] [ ] [ ] [ ]
* [ ] [ ]
* This method will return the following bounds:
* [ ] [ ]
*
* @param bounds unsorted bounds to find overlaps
* @return the non-overlapping bounds
*/
public static > Set> getNonOverlappingBounds(Iterable> bounds)
{
ArrayList> sortedBounds = Lists.newArrayList(bounds);
Collections.sort(sortedBounds, new Comparator>()
{
public int compare(Bounds o1, Bounds o2)
{
return o1.left.compareTo(o2.left);
}
});
Set> nonOverlappingBounds = Sets.newHashSet();
PeekingIterator> it = Iterators.peekingIterator(sortedBounds.iterator());
while (it.hasNext())
{
Bounds beginBound = it.next();
Bounds endBound = beginBound;
while (it.hasNext() && endBound.right.compareTo(it.peek().left) >= 0)
endBound = it.next();
nonOverlappingBounds.add(new Bounds<>(beginBound.left, endBound.right));
}
return nonOverlappingBounds;
}
}