X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/index/params/CategoryListParams.java?ds=sidebyside diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/index/params/CategoryListParams.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/index/params/CategoryListParams.java new file mode 100644 index 0000000..f40c4ab --- /dev/null +++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/index/params/CategoryListParams.java @@ -0,0 +1,149 @@ +package org.apache.lucene.facet.index.params; + +import java.io.IOException; +import java.io.Serializable; + +import org.apache.lucene.index.IndexReader; +import org.apache.lucene.index.Term; + +import org.apache.lucene.facet.search.CategoryListIterator; +import org.apache.lucene.facet.search.PayloadIntDecodingIterator; +import org.apache.lucene.facet.search.TotalFacetCounts; +import org.apache.lucene.facet.util.PartitionsUtils; +import org.apache.lucene.util.encoding.DGapIntEncoder; +import org.apache.lucene.util.encoding.IntDecoder; +import org.apache.lucene.util.encoding.IntEncoder; +import org.apache.lucene.util.encoding.SortingIntEncoder; +import org.apache.lucene.util.encoding.UniqueValuesIntEncoder; +import org.apache.lucene.util.encoding.VInt8IntEncoder; + +/** + * 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. + */ + +/** + * Contains parameters for a category list * + * + * @lucene.experimental + */ +public class CategoryListParams implements Serializable { + + /** The default term used to store the facets information. */ + public static final Term DEFAULT_TERM = new Term("$facets", "$fulltree$"); + + private final Term term; + + private final int hashCode; + + /** + * Constructs a default category list parameters object, using + * {@link #DEFAULT_TERM}. + */ + public CategoryListParams() { + this(DEFAULT_TERM); + } + + /** + * Constructs a category list parameters object, using the given {@link Term}. + * @param term who's payload hold the category-list. + */ + public CategoryListParams(Term term) { + this.term = term; + // Pre-compute the hashCode because these objects are immutable. Saves + // some time on the comparisons later. + this.hashCode = term.hashCode(); + } + + /** + * A {@link Term} who's payload holds the category-list. + */ + public final Term getTerm() { + return term; + } + + /** + * Allows to override how categories are encoded and decoded. A matching + * {@link IntDecoder} is provided by the {@link IntEncoder}. + *

+ * Default implementation creates a new Sorting(Unique(DGap)) encoder. + * Uniqueness in this regard means when the same category appears twice in a + * document, only one appearance would be encoded. This has effect on facet + * counting results. + *

+ * Some possible considerations when overriding may be: + *

+ * In any event when changing this value make sure you know what you are + * doing, and test the results - e.g. counts, if the application is about + * counting facets. + */ + public IntEncoder createEncoder() { + return new SortingIntEncoder(new UniqueValuesIntEncoder(new DGapIntEncoder(new VInt8IntEncoder()))); + } + + /** + * Equality is defined by the 'term' that defines this category list. + * Sub-classes should override this method if a more complex calculation + * is needed to ensure equality. + */ + @Override + public boolean equals(Object o) { + if (o == this) { + return true; + } + if (!(o instanceof CategoryListParams)) { + return false; + } + CategoryListParams other = (CategoryListParams) o; + if (this.hashCode != other.hashCode) { + return false; + } + // The above hashcodes might equal each other in the case of a collision, + // so at this point only directly term equality testing will settle + // the equality test. + return this.term.equals(other.term); + } + + /** + * Hashcode is similar to {@link #equals(Object)}, in that it uses + * the term that defines this category list to derive the hashcode. + * Subclasses need to ensure that equality/hashcode is correctly defined, + * or there could be side-effects in the {@link TotalFacetCounts} caching + * mechanism (as the filename for a Total Facet Counts array cache + * is dependent on the hashCode, so it should consistently return the same + * hash for identity). + */ + @Override + public int hashCode() { + return this.hashCode; + } + + /** + * Create the category list iterator for the specified partition. + */ + public CategoryListIterator createCategoryListIterator(IndexReader reader, + int partition) throws IOException { + String categoryListTermStr = PartitionsUtils.partitionName(this, partition); + Term payloadTerm = term.createTerm(categoryListTermStr); + return new PayloadIntDecodingIterator(reader, payloadTerm, + createEncoder().createMatchingDecoder()); + } + +} \ No newline at end of file