package org.apache.lucene.search.spans;
/**
* 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.
*/
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.Query;
import org.apache.lucene.util.ToStringUtils;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Set;
/** Removes matches which overlap with another SpanQuery. */
public class SpanNotQuery extends SpanQuery implements Cloneable {
private SpanQuery include;
private SpanQuery exclude;
/** Construct a SpanNotQuery matching spans from <code>include</code> which
* have no overlap with spans from <code>exclude</code>.*/
public SpanNotQuery(SpanQuery include, SpanQuery exclude) {
this.include = include;
this.exclude = exclude;
if (!include.getField().equals(exclude.getField()))
throw new IllegalArgumentException("Clauses must have same field.");
}
/** Return the SpanQuery whose matches are filtered. */
public SpanQuery getInclude() { return include; }
/** Return the SpanQuery whose matches must not overlap those returned. */
public SpanQuery getExclude() { return exclude; }
@Override
public String getField() { return include.getField(); }
@Override
public void extractTerms(Set<Term> terms) { include.extractTerms(terms); }
@Override
public String toString(String field) {
StringBuilder buffer = new StringBuilder();
buffer.append("spanNot(");
buffer.append(include.toString(field));
buffer.append(", ");
buffer.append(exclude.toString(field));
buffer.append(")");
buffer.append(ToStringUtils.boost(getBoost()));
return buffer.toString();
}
@Override
public Object clone() {
SpanNotQuery spanNotQuery = new SpanNotQuery((SpanQuery)include.clone(),(SpanQuery) exclude.clone());
spanNotQuery.setBoost(getBoost());
return spanNotQuery;
}
@Override
public Spans getSpans(final IndexReader reader) throws IOException {
return new Spans() {
private Spans includeSpans = include.getSpans(reader);
private boolean moreInclude = true;
private Spans excludeSpans = exclude.getSpans(reader);
private boolean moreExclude = excludeSpans.next();
@Override
public boolean next() throws IOException {
if (moreInclude) // move to next include
moreInclude = includeSpans.next();
while (moreInclude && moreExclude) {
if (includeSpans.doc() > excludeSpans.doc()) // skip exclude
moreExclude = excludeSpans.skipTo(includeSpans.doc());
while (moreExclude // while exclude is before
&& includeSpans.doc() == excludeSpans.doc()
&& excludeSpans.end() <= includeSpans.start()) {
moreExclude = excludeSpans.next(); // increment exclude
}
if (!moreExclude // if no intersection
|| includeSpans.doc() != excludeSpans.doc()
|| includeSpans.end() <= excludeSpans.start())
break; // we found a match
moreInclude = includeSpans.next(); // intersected: keep scanning
}
return moreInclude;
}
@Override
public boolean skipTo(int target) throws IOException {
if (moreInclude) // skip include
moreInclude = includeSpans.skipTo(target);
if (!moreInclude)
return false;
if (moreExclude // skip exclude
&& includeSpans.doc() > excludeSpans.doc())
moreExclude = excludeSpans.skipTo(includeSpans.doc());
while (moreExclude // while exclude is before
&& includeSpans.doc() == excludeSpans.doc()
&& excludeSpans.end() <= includeSpans.start()) {
moreExclude = excludeSpans.next(); // increment exclude
}
if (!moreExclude // if no intersection
|| includeSpans.doc() != excludeSpans.doc()
|| includeSpans.end() <= excludeSpans.start())
return true; // we found a match
return next(); // scan to next match
}
@Override
public int doc() { return includeSpans.doc(); }
@Override
public int start() { return includeSpans.start(); }
@Override
public int end() { return includeSpans.end(); }
// TODO: Remove warning after API has been finalized
@Override
public Collection<byte[]> getPayload() throws IOException {
ArrayList<byte[]> result = null;
if (includeSpans.isPayloadAvailable()) {
result = new ArrayList<byte[]>(includeSpans.getPayload());
}
return result;
}
// TODO: Remove warning after API has been finalized
@Override
public boolean isPayloadAvailable() {
return includeSpans.isPayloadAvailable();
}
@Override
public String toString() {
return "spans(" + SpanNotQuery.this.toString() + ")";
}
};
}
@Override
public Query rewrite(IndexReader reader) throws IOException {
SpanNotQuery clone = null;
SpanQuery rewrittenInclude = (SpanQuery) include.rewrite(reader);
if (rewrittenInclude != include) {
clone = (SpanNotQuery) this.clone();
clone.include = rewrittenInclude;
}
SpanQuery rewrittenExclude = (SpanQuery) exclude.rewrite(reader);
if (rewrittenExclude != exclude) {
if (clone == null) clone = (SpanNotQuery) this.clone();
clone.exclude = rewrittenExclude;
}
if (clone != null) {
return clone; // some clauses rewrote
} else {
return this; // no clauses rewrote
}
}
/** Returns true iff <code>o</code> is equal to this. */
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof SpanNotQuery)) return false;
SpanNotQuery other = (SpanNotQuery)o;
return this.include.equals(other.include)
&& this.exclude.equals(other.exclude)
&& this.getBoost() == other.getBoost();
}
@Override
public int hashCode() {
int h = include.hashCode();
h = (h<<1) | (h >>> 31); // rotate left
h ^= exclude.hashCode();
h = (h<<1) | (h >>> 31); // rotate left
h ^= Float.floatToRawIntBits(getBoost());
return h;
}
}