/**
* Copyright 2014 National University of Ireland, Galway.
*
* This file is part of the SIREn project. Project and contact information:
*
* https://github.com/rdelbru/SIREn
*
* 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 org.sindice.siren.search.node;
import java.io.IOException;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.NumericRangeQuery;
import org.apache.lucene.search.TermRangeQuery;
import org.apache.lucene.search.TermRangeTermsEnum;
import org.apache.lucene.util.AttributeSource;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.ToStringUtils;
/**
* A {@link NodePrimitiveQuery} that matches documents within an range of terms.
*
* <p>This query matches the documents looking for terms that fall into the
* supplied range according to {@link
* Byte#compareTo(Byte)}. It is not intended
* for numerical ranges; use {@link NumericRangeQuery} instead.
*
* <p>This query uses the {@link
* MultiNodeTermQuery#CONSTANT_SCORE_AUTO_REWRITE_DEFAULT}
* rewrite method.
*
* <p> Code taken from {@link TermRangeQuery} and adapted for SIREn.
*/
public class NodeTermRangeQuery extends MultiNodeTermQuery {
private final BytesRef lowerTerm;
private final BytesRef upperTerm;
private final boolean includeLower;
private final boolean includeUpper;
/**
* Constructs a query selecting all terms greater/equal than <code>lowerTerm</code>
* but less/equal than <code>upperTerm</code>.
*
* <p>
* If an endpoint is null, it is said
* to be "open". Either or both endpoints may be open. Open endpoints may not
* be exclusive (you can't select all but the first or last term without
* explicitly specifying the term to exclude.)
*
* @param field The field that holds both lower and upper terms.
* @param lowerTerm
* The term text at the lower end of the range
* @param upperTerm
* The term text at the upper end of the range
* @param includeLower
* If true, the <code>lowerTerm</code> is
* included in the range.
* @param includeUpper
* If true, the <code>upperTerm</code> is
* included in the range.
*/
public NodeTermRangeQuery(final String field, final BytesRef lowerTerm,
final BytesRef upperTerm,
final boolean includeLower,
final boolean includeUpper) {
super(field);
this.lowerTerm = lowerTerm;
this.upperTerm = upperTerm;
this.includeLower = includeLower;
this.includeUpper = includeUpper;
}
/**
* Factory that creates a new TermRangeQuery using Strings for term text.
*/
public static NodeTermRangeQuery newStringRange(final String field,
final String lowerTerm,
final String upperTerm,
final boolean includeLower,
final boolean includeUpper) {
final BytesRef lower = lowerTerm == null ? null : new BytesRef(lowerTerm);
final BytesRef upper = upperTerm == null ? null : new BytesRef(upperTerm);
return new NodeTermRangeQuery(field, lower, upper, includeLower, includeUpper);
}
/** Returns the lower value of this range query */
public BytesRef getLowerTerm() { return lowerTerm; }
/** Returns the upper value of this range query */
public BytesRef getUpperTerm() { return upperTerm; }
/** Returns <code>true</code> if the lower endpoint is inclusive */
public boolean includesLower() { return includeLower; }
/** Returns <code>true</code> if the upper endpoint is inclusive */
public boolean includesUpper() { return includeUpper; }
@Override
protected TermsEnum getTermsEnum(final Terms terms, final AttributeSource atts) throws IOException {
if (lowerTerm != null && upperTerm != null && lowerTerm.compareTo(upperTerm) > 0) {
return TermsEnum.EMPTY;
}
final TermsEnum tenum = terms.iterator(null);
if ((lowerTerm == null || (includeLower && lowerTerm.length == 0)) && upperTerm == null) {
return tenum;
}
return new TermRangeTermsEnum(tenum,
lowerTerm, upperTerm, includeLower, includeUpper);
}
/** Prints a user-readable version of this query. */
@Override
public String toString(final String field) {
final StringBuffer buffer = new StringBuffer();
buffer.append(includeLower ? '[' : '{');
// TODO: all these toStrings for queries should just output the bytes, it might not be UTF-8!
buffer.append(lowerTerm != null ? ("*".equals(lowerTerm.utf8ToString()) ? "\\*" : lowerTerm.utf8ToString()) : "*");
buffer.append(" TO ");
buffer.append(upperTerm != null ? ("*".equals(upperTerm.utf8ToString()) ? "\\*" : upperTerm.utf8ToString()) : "*");
buffer.append(includeUpper ? ']' : '}');
buffer.append(ToStringUtils.boost(this.getBoost()));
return this.wrapToStringWithDatatype(buffer).toString();
}
@Override
public int hashCode() {
final int prime = 31;
int result = super.hashCode();
result = prime * result + (includeLower ? 1231 : 1237);
result = prime * result + (includeUpper ? 1231 : 1237);
result = prime * result + ((lowerTerm == null) ? 0 : lowerTerm.hashCode());
result = prime * result + ((upperTerm == null) ? 0 : upperTerm.hashCode());
return result;
}
@Override
public boolean equals(final Object obj) {
if (this == obj)
return true;
if (!super.equals(obj))
return false;
if (this.getClass() != obj.getClass())
return false;
final NodeTermRangeQuery other = (NodeTermRangeQuery) obj;
if (includeLower != other.includeLower)
return false;
if (includeUpper != other.includeUpper)
return false;
if (lowerTerm == null) {
if (other.lowerTerm != null)
return false;
} else if (!lowerTerm.equals(other.lowerTerm))
return false;
if (upperTerm == null) {
if (other.upperTerm != null)
return false;
} else if (!upperTerm.equals(other.upperTerm))
return false;
return true;
}
}