/*
* 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.lucene.util.bkd;
import java.io.Closeable;
import java.io.IOException;
import org.apache.lucene.util.LongBitSet;
/** One pass iterator through all points previously written with a
* {@link PointWriter}, abstracting away whether points a read
* from (offline) disk or simple arrays in heap.
*
* @lucene.internal */
public abstract class PointReader implements Closeable {
/** Returns false once iteration is done, else true. */
public abstract boolean next() throws IOException;
/** Returns the packed byte[] value */
public abstract byte[] packedValue();
/** Point ordinal */
public abstract long ord();
/** DocID for this point */
public abstract int docID();
/** Iterates through the next {@code count} ords, marking them in the provided {@code ordBitSet}. */
public void markOrds(long count, LongBitSet ordBitSet) throws IOException {
for(int i=0;i<count;i++) {
boolean result = next();
if (result == false) {
throw new IllegalStateException("did not see enough points from reader=" + this);
}
assert ordBitSet.get(ord()) == false: "ord=" + ord() + " was seen twice from " + this;
ordBitSet.set(ord());
}
}
/** Splits this reader into left and right partitions */
public long split(long count, LongBitSet rightTree, PointWriter left, PointWriter right, boolean doClearBits) throws IOException {
// Partition this source according to how the splitDim split the values:
long rightCount = 0;
for (long i=0;i<count;i++) {
boolean result = next();
assert result;
byte[] packedValue = packedValue();
long ord = ord();
int docID = docID();
if (rightTree.get(ord)) {
right.append(packedValue, ord, docID);
rightCount++;
if (doClearBits) {
rightTree.clear(ord);
}
} else {
left.append(packedValue, ord, docID);
}
}
return rightCount;
}
}