| package org.apache.lucene.index; |
| |
| /* |
| * 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 java.util.Arrays; |
| |
| import org.apache.lucene.util.BytesRef; |
| |
| /** |
| * Maintains a {@link IndexReader} {@link TermState} view over |
| * {@link IndexReader} instances containing a single term. The |
| * {@link TermContext} doesn't track if the given {@link TermState} |
| * objects are valid, neither if the {@link TermState} instances refer to the |
| * same terms in the associated readers. |
| * |
| * @lucene.experimental |
| */ |
| public final class TermContext { |
| |
| /** Holds the {@link IndexReaderContext} of the top-level |
| * {@link IndexReader}, used internally only for |
| * asserting. |
| * |
| * @lucene.internal */ |
| public final IndexReaderContext topReaderContext; |
| private final TermState[] states; |
| private int docFreq; |
| private long totalTermFreq; |
| |
| //public static boolean DEBUG = BlockTreeTermsWriter.DEBUG; |
| |
| /** |
| * Creates an empty {@link TermContext} from a {@link IndexReaderContext} |
| */ |
| public TermContext(IndexReaderContext context) { |
| assert context != null && context.isTopLevel; |
| topReaderContext = context; |
| docFreq = 0; |
| final int len; |
| if (context.leaves() == null) { |
| len = 1; |
| } else { |
| len = context.leaves().size(); |
| } |
| states = new TermState[len]; |
| } |
| |
| /** |
| * Creates a {@link TermContext} with an initial {@link TermState}, |
| * {@link IndexReader} pair. |
| */ |
| public TermContext(IndexReaderContext context, TermState state, int ord, int docFreq, long totalTermFreq) { |
| this(context); |
| register(state, ord, docFreq, totalTermFreq); |
| } |
| |
| /** |
| * Creates a {@link TermContext} from a top-level {@link IndexReaderContext} and the |
| * given {@link Term}. This method will lookup the given term in all context's leaf readers |
| * and register each of the readers containing the term in the returned {@link TermContext} |
| * using the leaf reader's ordinal. |
| * <p> |
| * Note: the given context must be a top-level context. |
| */ |
| public static TermContext build(IndexReaderContext context, Term term) |
| throws IOException { |
| assert context != null && context.isTopLevel; |
| final String field = term.field(); |
| final BytesRef bytes = term.bytes(); |
| final TermContext perReaderTermState = new TermContext(context); |
| //if (DEBUG) System.out.println("prts.build term=" + term); |
| for (final AtomicReaderContext ctx : context.leaves()) { |
| //if (DEBUG) System.out.println(" r=" + leaves[i].reader); |
| final Fields fields = ctx.reader().fields(); |
| if (fields != null) { |
| final Terms terms = fields.terms(field); |
| if (terms != null) { |
| final TermsEnum termsEnum = terms.iterator(null); |
| if (termsEnum.seekExact(bytes)) { |
| final TermState termState = termsEnum.termState(); |
| //if (DEBUG) System.out.println(" found"); |
| perReaderTermState.register(termState, ctx.ord, termsEnum.docFreq(), termsEnum.totalTermFreq()); |
| } |
| } |
| } |
| } |
| return perReaderTermState; |
| } |
| |
| /** |
| * Clears the {@link TermContext} internal state and removes all |
| * registered {@link TermState}s |
| */ |
| public void clear() { |
| docFreq = 0; |
| Arrays.fill(states, null); |
| } |
| |
| /** |
| * Registers and associates a {@link TermState} with an leaf ordinal. The leaf ordinal |
| * should be derived from a {@link IndexReaderContext}'s leaf ord. |
| */ |
| public void register(TermState state, final int ord, final int docFreq, final long totalTermFreq) { |
| assert state != null : "state must not be null"; |
| assert ord >= 0 && ord < states.length; |
| assert states[ord] == null : "state for ord: " + ord |
| + " already registered"; |
| this.docFreq += docFreq; |
| if (this.totalTermFreq >= 0 && totalTermFreq >= 0) |
| this.totalTermFreq += totalTermFreq; |
| else |
| this.totalTermFreq = -1; |
| states[ord] = state; |
| } |
| |
| /** |
| * Returns the {@link TermState} for an leaf ordinal or <code>null</code> if no |
| * {@link TermState} for the ordinal was registered. |
| * |
| * @param ord |
| * the readers leaf ordinal to get the {@link TermState} for. |
| * @return the {@link TermState} for the given readers ord or <code>null</code> if no |
| * {@link TermState} for the reader was registered |
| */ |
| public TermState get(int ord) { |
| assert ord >= 0 && ord < states.length; |
| return states[ord]; |
| } |
| |
| /** |
| * Returns the accumulated document frequency of all {@link TermState} |
| * instances passed to {@link #register(TermState, int, int, long)}. |
| * @return the accumulated document frequency of all {@link TermState} |
| * instances passed to {@link #register(TermState, int, int, long)}. |
| */ |
| public int docFreq() { |
| return docFreq; |
| } |
| |
| /** |
| * Returns the accumulated term frequency of all {@link TermState} |
| * instances passed to {@link #register(TermState, int, int, long)}. |
| * @return the accumulated term frequency of all {@link TermState} |
| * instances passed to {@link #register(TermState, int, int, long)}. |
| */ |
| public long totalTermFreq() { |
| return totalTermFreq; |
| } |
| |
| /** expert: only available for queries that want to lie about docfreq |
| * @lucene.internal */ |
| public void setDocFreq(int docFreq) { |
| this.docFreq = docFreq; |
| } |
| } |