--- /dev/null
+package org.apache.lucene.search.vectorhighlight;
+
+/**
+ * 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 java.io.IOException;
+
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.highlight.Encoder;
+
+/**
+ * Another highlighter implementation.
+ *
+ */
+public class FastVectorHighlighter {
+
+ public static final boolean DEFAULT_PHRASE_HIGHLIGHT = true;
+ public static final boolean DEFAULT_FIELD_MATCH = true;
+ private final boolean phraseHighlight;
+ private final boolean fieldMatch;
+ private final FragListBuilder fragListBuilder;
+ private final FragmentsBuilder fragmentsBuilder;
+ private int phraseLimit = Integer.MAX_VALUE;
+
+ /**
+ * the default constructor.
+ */
+ public FastVectorHighlighter(){
+ this( DEFAULT_PHRASE_HIGHLIGHT, DEFAULT_FIELD_MATCH );
+ }
+
+ /**
+ * a constructor. Using {@link SimpleFragListBuilder} and {@link ScoreOrderFragmentsBuilder}.
+ *
+ * @param phraseHighlight true or false for phrase highlighting
+ * @param fieldMatch true of false for field matching
+ */
+ public FastVectorHighlighter( boolean phraseHighlight, boolean fieldMatch ){
+ this( phraseHighlight, fieldMatch, new SimpleFragListBuilder(), new ScoreOrderFragmentsBuilder() );
+ }
+
+ /**
+ * a constructor. A {@link FragListBuilder} and a {@link FragmentsBuilder} can be specified (plugins).
+ *
+ * @param phraseHighlight true of false for phrase highlighting
+ * @param fieldMatch true of false for field matching
+ * @param fragListBuilder an instance of {@link FragListBuilder}
+ * @param fragmentsBuilder an instance of {@link FragmentsBuilder}
+ */
+ public FastVectorHighlighter( boolean phraseHighlight, boolean fieldMatch,
+ FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder ){
+ this.phraseHighlight = phraseHighlight;
+ this.fieldMatch = fieldMatch;
+ this.fragListBuilder = fragListBuilder;
+ this.fragmentsBuilder = fragmentsBuilder;
+ }
+
+ /**
+ * create a {@link FieldQuery} object.
+ *
+ * @param query a query
+ * @return the created {@link FieldQuery} object
+ */
+ public FieldQuery getFieldQuery( Query query ) {
+ // TODO: should we deprecate this?
+ // because if there is no reader, then we cannot rewrite MTQ.
+ try {
+ return new FieldQuery( query, null, phraseHighlight, fieldMatch );
+ } catch (IOException e) {
+ // should never be thrown when reader is null
+ throw new RuntimeException (e);
+ }
+ }
+
+ /**
+ * create a {@link FieldQuery} object.
+ *
+ * @param query a query
+ * @return the created {@link FieldQuery} object
+ */
+ public FieldQuery getFieldQuery( Query query, IndexReader reader ) throws IOException {
+ return new FieldQuery( query, reader, phraseHighlight, fieldMatch );
+ }
+
+ /**
+ * return the best fragment.
+ *
+ * @param fieldQuery {@link FieldQuery} object
+ * @param reader {@link IndexReader} of the index
+ * @param docId document id to be highlighted
+ * @param fieldName field of the document to be highlighted
+ * @param fragCharSize the length (number of chars) of a fragment
+ * @return the best fragment (snippet) string
+ * @throws IOException
+ */
+ public final String getBestFragment( final FieldQuery fieldQuery, IndexReader reader, int docId,
+ String fieldName, int fragCharSize ) throws IOException {
+ FieldFragList fieldFragList =
+ getFieldFragList( fragListBuilder, fieldQuery, reader, docId, fieldName, fragCharSize );
+ return fragmentsBuilder.createFragment( reader, docId, fieldName, fieldFragList );
+ }
+
+ /**
+ * return the best fragments.
+ *
+ * @param fieldQuery {@link FieldQuery} object
+ * @param reader {@link IndexReader} of the index
+ * @param docId document id to be highlighted
+ * @param fieldName field of the document to be highlighted
+ * @param fragCharSize the length (number of chars) of a fragment
+ * @param maxNumFragments maximum number of fragments
+ * @return created fragments or null when no fragments created.
+ * size of the array can be less than maxNumFragments
+ * @throws IOException
+ */
+ public final String[] getBestFragments( final FieldQuery fieldQuery, IndexReader reader, int docId,
+ String fieldName, int fragCharSize, int maxNumFragments ) throws IOException {
+ FieldFragList fieldFragList =
+ getFieldFragList( fragListBuilder, fieldQuery, reader, docId, fieldName, fragCharSize );
+ return fragmentsBuilder.createFragments( reader, docId, fieldName, fieldFragList, maxNumFragments );
+ }
+
+ /**
+ * return the best fragment.
+ *
+ * @param fieldQuery {@link FieldQuery} object
+ * @param reader {@link IndexReader} of the index
+ * @param docId document id to be highlighted
+ * @param fieldName field of the document to be highlighted
+ * @param fragCharSize the length (number of chars) of a fragment
+ * @param fragListBuilder {@link FragListBuilder} object
+ * @param fragmentsBuilder {@link FragmentsBuilder} object
+ * @param preTags pre-tags to be used to highlight terms
+ * @param postTags post-tags to be used to highlight terms
+ * @param encoder an encoder that generates encoded text
+ * @return the best fragment (snippet) string
+ * @throws IOException
+ */
+ public final String getBestFragment( final FieldQuery fieldQuery, IndexReader reader, int docId,
+ String fieldName, int fragCharSize,
+ FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder,
+ String[] preTags, String[] postTags, Encoder encoder ) throws IOException {
+ FieldFragList fieldFragList = getFieldFragList( fragListBuilder, fieldQuery, reader, docId, fieldName, fragCharSize );
+ return fragmentsBuilder.createFragment( reader, docId, fieldName, fieldFragList, preTags, postTags, encoder );
+ }
+
+ /**
+ * return the best fragments.
+ *
+ * @param fieldQuery {@link FieldQuery} object
+ * @param reader {@link IndexReader} of the index
+ * @param docId document id to be highlighted
+ * @param fieldName field of the document to be highlighted
+ * @param fragCharSize the length (number of chars) of a fragment
+ * @param maxNumFragments maximum number of fragments
+ * @param fragListBuilder {@link FragListBuilder} object
+ * @param fragmentsBuilder {@link FragmentsBuilder} object
+ * @param preTags pre-tags to be used to highlight terms
+ * @param postTags post-tags to be used to highlight terms
+ * @param encoder an encoder that generates encoded text
+ * @return created fragments or null when no fragments created.
+ * size of the array can be less than maxNumFragments
+ * @throws IOException
+ */
+ public final String[] getBestFragments( final FieldQuery fieldQuery, IndexReader reader, int docId,
+ String fieldName, int fragCharSize, int maxNumFragments,
+ FragListBuilder fragListBuilder, FragmentsBuilder fragmentsBuilder,
+ String[] preTags, String[] postTags, Encoder encoder ) throws IOException {
+ FieldFragList fieldFragList =
+ getFieldFragList( fragListBuilder, fieldQuery, reader, docId, fieldName, fragCharSize );
+ return fragmentsBuilder.createFragments( reader, docId, fieldName, fieldFragList, maxNumFragments,
+ preTags, postTags, encoder );
+ }
+
+ private FieldFragList getFieldFragList( FragListBuilder fragListBuilder,
+ final FieldQuery fieldQuery, IndexReader reader, int docId,
+ String fieldName, int fragCharSize ) throws IOException {
+ FieldTermStack fieldTermStack = new FieldTermStack( reader, docId, fieldName, fieldQuery );
+ FieldPhraseList fieldPhraseList = new FieldPhraseList( fieldTermStack, fieldQuery, phraseLimit );
+ return fragListBuilder.createFieldFragList( fieldPhraseList, fragCharSize );
+ }
+
+ /**
+ * return whether phraseHighlight or not.
+ *
+ * @return whether phraseHighlight or not
+ */
+ public boolean isPhraseHighlight(){ return phraseHighlight; }
+
+ /**
+ * return whether fieldMatch or not.
+ *
+ * @return whether fieldMatch or not
+ */
+ public boolean isFieldMatch(){ return fieldMatch; }
+
+ /**
+ * @return the maximum number of phrases to analyze when searching for the highest-scoring phrase.
+ */
+ public int getPhraseLimit () { return phraseLimit; }
+
+ /**
+ * set the maximum number of phrases to analyze when searching for the highest-scoring phrase.
+ * The default is unlimited (Integer.MAX_VALUE).
+ */
+ public void setPhraseLimit (int phraseLimit) { this.phraseLimit = phraseLimit; }
+}
fnp / pylucene.git / blobdiff