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/*
* 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.solr.search;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.util.Accountable;
import org.apache.lucene.util.RamUsageEstimator;
/** A hash key encapsulating a query, a list of filters, and a sort */
public final class QueryResultKey implements Accountable {
private static final long BASE_RAM_BYTES_USED =
RamUsageEstimator.shallowSizeOfInstance(QueryResultKey.class);
private static final long BASE_SF_RAM_BYTES_USED =
RamUsageEstimator.shallowSizeOfInstance(SortField.class);
final Query query;
final Sort sort;
final List sfields;
final List filters;
final int nc_flags; // non-comparable flags... ignored by hashCode and equals
final int minExactCount;
final boolean distribStatsDisabled;
private final int hc; // cached hashCode
private final long ramBytesUsed; // cached
public QueryResultKey(Query query, List filters, Sort sort, int nc_flags) {
this(query, filters, sort, nc_flags, Integer.MAX_VALUE, false);
}
public QueryResultKey(
Query query, List filters, Sort sort, int nc_flags, int minExactCount) {
this(query, filters, sort, nc_flags, minExactCount, false);
}
public QueryResultKey(
Query query,
List filters,
Sort sort,
int nc_flags,
int minExactCount,
boolean distribStatsDisabled) {
this.query = query;
this.sort = sort;
this.nc_flags = nc_flags;
this.minExactCount = minExactCount;
this.distribStatsDisabled = distribStatsDisabled;
int h = query.hashCode();
if (filters == null) {
this.filters = null;
} else {
this.filters = filters.stream().filter(Objects::nonNull).collect(Collectors.toList());
for (Query filt : this.filters) {
// NOTE: simple summation used here so keys with the same filters but in
// different orders get the same hashCode
h += filt.hashCode();
}
}
if (this.sort == null) {
this.sfields = List.of();
} else {
this.sfields =
Arrays.stream(sort.getSort()).filter(Objects::nonNull).collect(Collectors.toList());
}
long ramSfields = RamUsageEstimator.NUM_BYTES_ARRAY_HEADER;
for (SortField sf : sfields) {
h = h * 29 + sf.hashCode();
ramSfields += BASE_SF_RAM_BYTES_USED + RamUsageEstimator.sizeOfObject(sf.getField());
}
h = h * 31 + minExactCount;
hc = h;
ramBytesUsed =
BASE_RAM_BYTES_USED
+ ramSfields
+ RamUsageEstimator.sizeOfObject(query, RamUsageEstimator.QUERY_DEFAULT_RAM_BYTES_USED)
+ RamUsageEstimator.sizeOfObject(
this.filters, RamUsageEstimator.QUERY_DEFAULT_RAM_BYTES_USED);
}
@Override
public int hashCode() {
return hc;
}
@Override
public boolean equals(Object o) {
if (o == this) return true;
if (!(o instanceof QueryResultKey)) return false;
QueryResultKey other = (QueryResultKey) o;
// fast check of the whole hash code... most hash tables will only use
// some of the bits, so if this is a hash collision, it's still likely
// that the full cached hash code will be different.
if (this.hc != other.hc) return false;
// check for the thing most likely to be different (and the fastest things)
// first.
if (this.sfields.size() != other.sfields.size()) return false;
if (!this.query.equals(other.query)) return false;
if (!unorderedCompare(this.filters, other.filters)) return false;
if (this.minExactCount != other.minExactCount) return false;
if (this.distribStatsDisabled != other.distribStatsDisabled) return false;
for (int i = 0; i < sfields.size(); i++) {
SortField sf1 = this.sfields.get(i);
SortField sf2 = other.sfields.get(i);
if (!sf1.equals(sf2)) return false;
}
return true;
}
/**
* compares the two lists of queries in an unordered manner such that this method returns true if
* the 2 lists are the same size, and contain the same elements.
*
* This method should only be used if the lists come from QueryResultKeys which have already
* been found to have equal hashCodes, since the unordered comparison aspects of the logic are not
* cheap.
*
* @return true if the lists of equivalent other then the ordering
*/
private static boolean unorderedCompare(List fqList1, List fqList2) {
// Do fast version first, expecting that filters are usually in the same order
//
// Fall back to unordered compare logic on the first non-equal elements.
// The slower unorderedCompare should pretty much never be called if filter
// lists are generally ordered consistently
if (fqList1 == fqList2) return true; // takes care of identity and null cases
if (fqList1 == null || fqList2 == null) return false;
int sz = fqList1.size();
if (sz != fqList2.size()) return false;
for (int i = 0; i < sz; i++) {
if (!fqList1.get(i).equals(fqList2.get(i))) {
return unorderedCompare(fqList1, fqList2, i);
}
}
return true;
}
/**
* Does an unordered comparison of the elements of two lists of queries starting at the specified
* start index.
*
* This method should only be called on lists which are the same size, and where all items with
* an index less then the specified start index are the same.
*
* @return true if the list items after start are equivalent other then the ordering
*/
private static boolean unorderedCompare(List fqList1, List fqList2, int start) {
assert null != fqList1;
assert null != fqList2;
final int sz = fqList1.size();
assert fqList2.size() == sz;
// SOLR-5618: if we had a guarantee that the lists never contained any duplicates,
// this logic could be a lot simpler
//
// (And of course: if the SolrIndexSearcher / QueryCommmand was ever changed to
// sort the filter query list, then this whole method could be eliminated).
final ArrayList set2 = new ArrayList<>(fqList2.subList(start, sz));
for (int i = start; i < sz; i++) {
Query q1 = fqList1.get(i);
if (!set2.remove(q1)) {
return false;
}
}
return set2.isEmpty();
}
@Override
public long ramBytesUsed() {
return ramBytesUsed;
}
}