/*
* Copyright 2014, Stratio.
*
* Licensed 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 com.stratio.cassandra.index.query;
import com.stratio.cassandra.index.schema.ColumnMapper;
import com.stratio.cassandra.index.schema.Schema;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.TermToBytesRefAttribute;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.QueryWrapperFilter;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.IOUtils;
import org.codehaus.jackson.annotate.JsonCreator;
import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.annotate.JsonSubTypes;
import org.codehaus.jackson.annotate.JsonTypeInfo;
import java.io.IOException;
/**
* The abstract base class for queries.
* <p/>
* Known subclasses are:
* <ul>
* <li> {@link BooleanCondition}
* <li> {@link FuzzyCondition}
* <li> {@link MatchCondition}
* <li> {@link PhraseCondition}
* <li> {@link PrefixCondition}
* <li> {@link RangeCondition}
* <li> {@link WildcardCondition}
* </ul>
*
* @author Andres de la Pena <adelapena@stratio.com>
*/
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
@JsonSubTypes({
@JsonSubTypes.Type(value = BooleanCondition.class, name = "boolean"),
@JsonSubTypes.Type(value = FuzzyCondition.class, name = "fuzzy"),
@JsonSubTypes.Type(value = LuceneCondition.class, name = "lucene"),
@JsonSubTypes.Type(value = MatchCondition.class, name = "match"),
@JsonSubTypes.Type(value = RangeCondition.class, name = "range"),
@JsonSubTypes.Type(value = PhraseCondition.class, name = "phrase"),
@JsonSubTypes.Type(value = PrefixCondition.class, name = "prefix"),
@JsonSubTypes.Type(value = RegexpCondition.class, name = "regexp"),
@JsonSubTypes.Type(value = WildcardCondition.class, name = "wildcard"),})
public abstract class Condition
{
public static final float DEFAULT_BOOST = 1.0f;
@JsonProperty("boost")
protected float boost;
/**
* @param boost The boost for this query clause. Documents matching this clause will (in addition to the normal
* weightings) have their score multiplied by {@code boost}.
*/
@JsonCreator
public Condition(@JsonProperty("boost") Float boost)
{
this.boost = boost == null ? DEFAULT_BOOST : boost;
}
/**
* Returns the Lucene's {@link Query} representation of this condition.
*
* @param schema The schema to be used.
* @return The Lucene's {@link Query} representation of this condition.
*/
public abstract Query query(Schema schema);
/**
* Returns the Lucene's {@link Filter} representation of this condition.
*
* @param schema The schema to be used.
* @return The Lucene's {@link Filter} representation of this condition.
*/
public Filter filter(Schema schema)
{
return new QueryWrapperFilter(query(schema));
}
protected String analyze(String field, String value, ColumnMapper<?> columnMapper)
{
TokenStream source = null;
try
{
Analyzer analyzer = columnMapper.analyzer();
source = analyzer.tokenStream(field, value);
source.reset();
TermToBytesRefAttribute termAtt = source.getAttribute(TermToBytesRefAttribute.class);
BytesRef bytes = termAtt.getBytesRef();
if (!source.incrementToken())
{
return null;
}
termAtt.fillBytesRef();
if (source.incrementToken())
{
throw new IllegalArgumentException("analyzer returned too many terms for multiTerm term: " + value);
}
source.end();
return BytesRef.deepCopyOf(bytes).utf8ToString();
}
catch (IOException e)
{
throw new RuntimeException("Error analyzing multiTerm term: " + value, e);
}
finally
{
IOUtils.closeWhileHandlingException(source);
}
}
}