| /* |
| * 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.datasketches.tuple; |
| |
| import static java.lang.Math.ceil; |
| import static java.lang.Math.max; |
| import static java.lang.Math.min; |
| import static org.apache.datasketches.HashOperations.hashInsertOnly; |
| import static org.apache.datasketches.HashOperations.hashSearch; |
| import static org.apache.datasketches.Util.MIN_LG_NOM_LONGS; |
| import static org.apache.datasketches.Util.ceilingPowerOf2; |
| |
| import java.lang.reflect.Array; |
| |
| import org.apache.datasketches.SketchesArgumentException; |
| import org.apache.datasketches.SketchesStateException; |
| |
| |
| /** |
| * Computes an intersection of two or more generic tuple sketches. |
| * A new instance represents the Universal Set. Because the Universal Set |
| * cannot be realized a <i>getResult()</i> on a new instance will produce an error. |
| * Every update() computes an intersection with the internal state, which will never |
| * grow larger and may be reduced to zero. |
| * |
| * @param <S> Type of Summary |
| */ |
| @SuppressWarnings("unchecked") |
| public class Intersection<S extends Summary> { |
| private final SummarySetOperations<S> summarySetOps_; |
| private boolean empty_; |
| private long thetaLong_; |
| private HashTables hashTables_; |
| private boolean firstCall_; |
| |
| /** |
| * Creates new instance |
| * @param summarySetOps instance of SummarySetOperations |
| */ |
| public Intersection(final SummarySetOperations<S> summarySetOps) { |
| summarySetOps_ = summarySetOps; |
| empty_ = false; // universal set at the start |
| thetaLong_ = Long.MAX_VALUE; |
| hashTables_ = new HashTables(); |
| firstCall_ = true; |
| } |
| |
| /** |
| * Updates the internal state by intersecting it with the given sketch. |
| * @param sketchIn input sketch to intersect with the internal state. It may not be null. |
| */ |
| public void update(final Sketch<S> sketchIn) { |
| if (sketchIn == null) { throw new SketchesArgumentException("Sketch may not be null"); } |
| final boolean firstCall = firstCall_; |
| firstCall_ = false; |
| |
| // input sketch could be first or next call |
| final long thetaLongIn = sketchIn.getThetaLong(); |
| final int countIn = sketchIn.getRetainedEntries(); |
| thetaLong_ = min(thetaLong_, thetaLongIn); //Theta rule |
| // Empty rule extended in case incoming sketch does not have empty bit properly set |
| empty_ |= (countIn == 0) && (thetaLongIn == Long.MAX_VALUE); |
| if (countIn == 0) { |
| hashTables_.clear(); |
| return; |
| } |
| // input sketch will have valid entries > 0 |
| |
| if (firstCall) { |
| final Sketch<S> firstSketch = sketchIn; |
| //Copy firstSketch data into local instance hashTables_ |
| hashTables_.fromSketch(firstSketch); |
| } |
| |
| //Next Call |
| else { |
| if (hashTables_.count_ == 0) { |
| return; |
| } |
| final Sketch<S> nextSketch = sketchIn; |
| //Match nextSketch data with local instance data, filtering by theta |
| final int maxMatchSize = min(hashTables_.count_, nextSketch.getRetainedEntries()); |
| |
| final long[] matchHashArr = new long[maxMatchSize]; |
| S[] matchSummaries = null; |
| int matchCount = 0; |
| |
| final SketchIterator<S> it = nextSketch.iterator(); |
| final Class<S> summaryType = (Class<S>) hashTables_.summaryTable_.getClass().getComponentType(); |
| while (it.next()) { |
| final long hash = it.getHash(); |
| if (hash >= thetaLong_) { continue; } |
| final int index = hashSearch(hashTables_.hashTable_, hashTables_.lgTableSize_, hash); |
| if (index < 0) { continue; } |
| //Copy the intersecting items from local hashTables_ |
| // sequentially into local matchHashArr_ and matchSummaries_ |
| final S mySummary = hashTables_.summaryTable_[index]; |
| |
| if (matchSummaries == null) { |
| matchSummaries = (S[]) Array.newInstance(summaryType, maxMatchSize); |
| } |
| matchHashArr[matchCount] = hash; |
| matchSummaries[matchCount] = summarySetOps_.intersection(mySummary, it.getSummary()); |
| matchCount++; |
| } |
| hashTables_.fromArrays(matchHashArr, matchSummaries, matchCount); |
| } |
| } |
| |
| /** |
| * Updates the internal set by intersecting it with the given Theta sketch. |
| * @param sketchIn input Theta Sketch to intersect with the internal state. It may not be null. |
| * @param summary the given proxy summary for the Theta Sketch, which doesn't have one. |
| * It may not be null. |
| */ |
| public void update(final org.apache.datasketches.theta.Sketch sketchIn, final S summary) { |
| if (sketchIn == null) { throw new SketchesArgumentException("Sketch may not be null"); } |
| if (summary == null) { throw new SketchesArgumentException("Summary cannot be null."); } |
| final boolean firstCall = firstCall_; |
| firstCall_ = false; |
| // input sketch is not null, could be first or next call |
| final long thetaLongIn = sketchIn.getThetaLong(); |
| final int countIn = sketchIn.getRetainedEntries(true); |
| thetaLong_ = min(thetaLong_, thetaLongIn); //Theta rule |
| // Empty rule extended in case incoming sketch does not have empty bit properly set |
| empty_ |= (countIn == 0) && (thetaLongIn == Long.MAX_VALUE); |
| if (countIn == 0) { |
| hashTables_.clear(); |
| return; |
| } |
| // input sketch will have valid entries > 0 |
| if (firstCall) { |
| final org.apache.datasketches.theta.Sketch firstSketch = sketchIn; |
| //Copy firstSketch data into local instance hashTables_ |
| hashTables_.fromSketch(firstSketch, summary); |
| } |
| |
| //Next Call |
| else { |
| if (hashTables_.count_ == 0) { |
| return; |
| } |
| final org.apache.datasketches.theta.Sketch nextSketch = sketchIn; |
| //Match nextSketch data with local instance data, filtering by theta |
| final int maxMatchSize = min(hashTables_.count_, nextSketch.getRetainedEntries(true)); |
| |
| final long[] matchHashArr = new long[maxMatchSize]; |
| S[] matchSummaries = null; |
| int matchCount = 0; |
| |
| final org.apache.datasketches.theta.HashIterator it = sketchIn.iterator(); |
| final Class<S> summaryType = (Class<S>) hashTables_.summaryTable_.getClass().getComponentType(); |
| while (it.next()) { |
| final long hash = it.get(); |
| if (hash >= thetaLong_) { continue; } |
| final int index = hashSearch(hashTables_.hashTable_, hashTables_.lgTableSize_, hash); |
| if (index < 0) { continue; } |
| //Copy the intersecting items from local hashTables_ |
| // sequentially into local matchHashArr and matchSummaries |
| final S mySummary = hashTables_.summaryTable_[index]; |
| |
| if (matchSummaries == null) { |
| matchSummaries = (S[]) Array.newInstance(summaryType, maxMatchSize); |
| } |
| matchHashArr[matchCount] = hash; |
| matchSummaries[matchCount] = summarySetOps_.intersection(mySummary, (S)mySummary.copy()); |
| matchCount++; |
| } |
| hashTables_.fromArrays(matchHashArr, matchSummaries, matchCount); |
| } |
| } |
| |
| /** |
| * Gets the internal set as a CompactSketch |
| * @return result of the intersections so far |
| */ |
| public CompactSketch<S> getResult() { |
| if (firstCall_) { |
| throw new SketchesStateException( |
| "getResult() with no intervening intersections is not a legal result."); |
| } |
| if (hashTables_.count_ == 0) { |
| return new CompactSketch<>(null, null, thetaLong_, empty_); |
| } |
| //Compact the hash tables |
| final int tableSize = hashTables_.hashTable_.length; |
| final long[] hashArr = new long[hashTables_.count_]; |
| S[] summaries = null; |
| final Class<S> summaryType = (Class<S>) hashTables_.summaryTable_.getClass().getComponentType(); |
| int cnt = 0; |
| for (int i = 0; i < tableSize; i++) { |
| final long hash = hashTables_.hashTable_[i]; |
| if ((hash == 0) || (hash > thetaLong_)) { continue; } |
| final S summary = hashTables_.summaryTable_[i]; |
| if (summaries == null) { |
| summaries = (S[]) Array.newInstance(summaryType, hashTables_.count_); |
| } |
| hashArr[cnt] = hash; |
| summaries[cnt] = summary; |
| cnt++; |
| } |
| assert cnt == hashTables_.count_; |
| return new CompactSketch<>(hashArr, summaries, thetaLong_, empty_); |
| } |
| |
| /** |
| * Resets the internal set to the initial state, which represents the Universal Set |
| */ |
| public void reset() { |
| empty_ = false; |
| thetaLong_ = Long.MAX_VALUE; |
| hashTables_.clear(); |
| firstCall_ = true; |
| } |
| |
| private static int getLgTableSize(final int count) { |
| final int tableSize = max(ceilingPowerOf2((int) ceil(count / 0.75)), 1 << MIN_LG_NOM_LONGS); |
| return Integer.numberOfTrailingZeros(tableSize); |
| } |
| |
| private class HashTables { |
| long[] hashTable_ = null; |
| S[] summaryTable_ = null; |
| int lgTableSize_ = 0; |
| int count_ = 0; |
| |
| HashTables() { } |
| |
| void fromSketch(final Sketch<S> sketch) { |
| count_ = sketch.getRetainedEntries(); |
| lgTableSize_ = getLgTableSize(count_); |
| S mySummary = null; |
| |
| hashTable_ = new long[1 << lgTableSize_]; |
| final SketchIterator<S> it = sketch.iterator(); |
| while (it.next()) { |
| final long hash = it.getHash(); |
| final int index = hashInsertOnly(hashTable_, lgTableSize_, hash); |
| mySummary = (S)it.getSummary().copy(); |
| if (summaryTable_ == null) { |
| summaryTable_ = (S[]) Array.newInstance(mySummary.getClass(), 1 << lgTableSize_); |
| } |
| summaryTable_[index] = mySummary; |
| } |
| } |
| |
| void fromSketch(final org.apache.datasketches.theta.Sketch sketch, final S summary) { |
| count_ = sketch.getRetainedEntries(true); |
| lgTableSize_ = getLgTableSize(count_); |
| S mySummary = null; |
| |
| hashTable_ = new long[1 << lgTableSize_]; |
| final org.apache.datasketches.theta.HashIterator it = sketch.iterator(); |
| while (it.next()) { |
| final long hash = it.get(); |
| final int index = hashInsertOnly(hashTable_, lgTableSize_, hash); |
| mySummary = summary; |
| if (summaryTable_ == null) { |
| summaryTable_ = (S[]) Array.newInstance(mySummary.getClass(), 1 << lgTableSize_); |
| } |
| summaryTable_[index] = mySummary; |
| } |
| } |
| |
| |
| void fromArrays(final long[] hashArr, final S[] summaryArr, final int count) { |
| count_ = count; |
| lgTableSize_ = getLgTableSize(count); |
| |
| S mySummary = null; |
| summaryTable_ = null; |
| hashTable_ = new long[1 << lgTableSize_]; |
| for (int i = 0; i < count; i++) { |
| final long hash = hashArr[i]; |
| final int index = hashInsertOnly(hashTable_, lgTableSize_, hash); |
| mySummary = summaryArr[i]; |
| if (summaryTable_ == null) { |
| summaryTable_ = (S[]) Array.newInstance(mySummary.getClass(), 1 << lgTableSize_); |
| } |
| summaryTable_[index] = summaryArr[i]; |
| } |
| } |
| |
| void clear() { |
| hashTable_ = null; |
| summaryTable_ = null; |
| lgTableSize_ = 0; |
| count_ = 0; |
| } |
| } |
| |
| } |