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/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.search.aggregations.bucket.significant.heuristics;
import org.elasticsearch.ElasticsearchParseException;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.query.QueryShardException;
import org.elasticsearch.script.ExecutableScript;
import org.elasticsearch.script.Script;
import org.elasticsearch.script.ScriptContext;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.support.XContentParseContext;
import org.elasticsearch.search.internal.SearchContext;
import java.io.IOException;
import java.util.Objects;
public class ScriptHeuristic extends SignificanceHeuristic {
public static final String NAME = "script_heuristic";
private final Script script;
// This class holds an executable form of the script with private variables ready for execution
// on a single search thread.
static class ExecutableScriptHeuristic extends ScriptHeuristic {
private final LongAccessor subsetSizeHolder;
private final LongAccessor supersetSizeHolder;
private final LongAccessor subsetDfHolder;
private final LongAccessor supersetDfHolder;
private final ExecutableScript executableScript;
ExecutableScriptHeuristic(Script script, ExecutableScript executableScript){
super(script);
subsetSizeHolder = new LongAccessor();
supersetSizeHolder = new LongAccessor();
subsetDfHolder = new LongAccessor();
supersetDfHolder = new LongAccessor();
this.executableScript = executableScript;
executableScript.setNextVar("_subset_freq", subsetDfHolder);
executableScript.setNextVar("_subset_size", subsetSizeHolder);
executableScript.setNextVar("_superset_freq", supersetDfHolder);
executableScript.setNextVar("_superset_size", supersetSizeHolder);
}
@Override
public double getScore(long subsetFreq, long subsetSize, long supersetFreq, long supersetSize) {
subsetSizeHolder.value = subsetSize;
supersetSizeHolder.value = supersetSize;
subsetDfHolder.value = subsetFreq;
supersetDfHolder.value = supersetFreq;
return ((Number) executableScript.run()).doubleValue();
}
}
public ScriptHeuristic(Script script) {
this.script = script;
}
/**
* Read from a stream.
*/
public ScriptHeuristic(StreamInput in) throws IOException {
this(new Script(in));
}
@Override
public void writeTo(StreamOutput out) throws IOException {
script.writeTo(out);
}
@Override
public SignificanceHeuristic rewrite(InternalAggregation.ReduceContext context) {
return new ExecutableScriptHeuristic(script, context.scriptService().executable(script, ScriptContext.Standard.AGGS));
}
@Override
public SignificanceHeuristic rewrite(SearchContext context) {
return new ExecutableScriptHeuristic(script, context.getQueryShardContext().getExecutableScript(script, ScriptContext.Standard.AGGS));
}
/**
* Calculates score with a script
*
* @param subsetFreq The frequency of the term in the selected sample
* @param subsetSize The size of the selected sample (typically number of docs)
* @param supersetFreq The frequency of the term in the superset from which the sample was taken
* @param supersetSize The size of the superset from which the sample was taken (typically number of docs)
* @return a "significance" score
*/
@Override
public double getScore(long subsetFreq, long subsetSize, long supersetFreq, long supersetSize) {
throw new UnsupportedOperationException("This scoring heuristic must have 'rewrite' called on it to provide a version ready for use");
}
@Override
public String getWriteableName() {
return NAME;
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, Params builderParams) throws IOException {
builder.startObject(NAME);
builder.field(Script.SCRIPT_PARSE_FIELD.getPreferredName());
script.toXContent(builder, builderParams);
builder.endObject();
return builder;
}
@Override
public int hashCode() {
return Objects.hash(script);
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
ScriptHeuristic other = (ScriptHeuristic) obj;
return Objects.equals(script, other.script);
}
public static SignificanceHeuristic parse(XContentParseContext context)
throws IOException, QueryShardException {
XContentParser parser = context.getParser();
String heuristicName = parser.currentName();
Script script = null;
XContentParser.Token token;
String currentFieldName = null;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token.equals(XContentParser.Token.FIELD_NAME)) {
currentFieldName = parser.currentName();
} else {
if (context.matchField(currentFieldName, Script.SCRIPT_PARSE_FIELD)) {
script = Script.parse(parser, context.getParseFieldMatcher(), context.getDefaultScriptLanguage());
} else {
throw new ElasticsearchParseException("failed to parse [{}] significance heuristic. unknown object [{}]", heuristicName, currentFieldName);
}
}
}
if (script == null) {
throw new ElasticsearchParseException("failed to parse [{}] significance heuristic. no script found in script_heuristic", heuristicName);
}
return new ScriptHeuristic(script);
}
public final class LongAccessor extends Number {
public long value;
@Override
public int intValue() {
return (int)value;
}
@Override
public long longValue() {
return value;
}
@Override
public float floatValue() {
return value;
}
@Override
public double doubleValue() {
return value;
}
@Override
public String toString() {
return Long.toString(value);
}
}
}