| /* |
| * 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.index; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.lucene.index.PointValues.IntersectVisitor; |
| import org.apache.lucene.util.FutureArrays; |
| |
| /** Simple utility class to track the current BKD stack based solely on calls to {@link IntersectVisitor#compare}. */ |
| public class PointsStackTracker { |
| |
| private final int numDims; |
| private final int bytesPerDim; |
| |
| public final List<Cell> stack = new ArrayList<>(); |
| |
| public class Cell { |
| public final byte[] minPackedValue; |
| public final byte[] maxPackedValue; |
| |
| public Cell(byte[] minPackedValue, byte[] maxPackedValue) { |
| this.minPackedValue = minPackedValue.clone(); |
| this.maxPackedValue = maxPackedValue.clone(); |
| } |
| |
| public boolean contains(Cell other) { |
| for(int dim=0;dim<numDims;dim++) { |
| int offset = dim * bytesPerDim; |
| // other.min < min? |
| if (FutureArrays.compareUnsigned(other.minPackedValue, offset, offset + bytesPerDim, minPackedValue, offset, offset + bytesPerDim) < 0) { |
| return false; |
| } |
| // other.max > max? |
| if (FutureArrays.compareUnsigned(other.maxPackedValue, offset, offset + bytesPerDim, maxPackedValue, offset, offset + bytesPerDim) > 0) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| } |
| |
| public PointsStackTracker(int numDims, int bytesPerDim) { |
| this.numDims = numDims; |
| this.bytesPerDim = bytesPerDim; |
| } |
| |
| public void onCompare(byte[] minPackedValue, byte[] maxPackedValue) { |
| Cell cell = new Cell(minPackedValue, maxPackedValue); |
| |
| // Pop stack: |
| while (stack.size() > 0 && stack.get(stack.size()-1).contains(cell) == false) { |
| stack.remove(stack.size()-1); |
| //System.out.println(" pop"); |
| } |
| |
| // Push stack: |
| stack.add(cell); |
| } |
| |
| // TODO: expose other details about the stack... |
| } |