| package org.apache.lucene.codecs; |
| |
| /* |
| * 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.Closeable; |
| import java.io.IOException; |
| |
| import org.apache.lucene.index.FieldInfo; |
| import org.apache.lucene.index.Fields; |
| import org.apache.lucene.index.MergeState; |
| import org.apache.lucene.index.SegmentWriteState; // javadocs |
| import org.apache.lucene.index.Terms; |
| |
| /** |
| * Abstract API that consumes terms, doc, freq, prox, offset and |
| * payloads postings. Concrete implementations of this |
| * actually do "something" with the postings (write it into |
| * the index in a specific format). |
| * <p> |
| * The lifecycle is: |
| * <ol> |
| * <li>FieldsConsumer is created by |
| * {@link PostingsFormat#fieldsConsumer(SegmentWriteState)}. |
| * <li>For each field, {@link #addField(FieldInfo)} is called, |
| * returning a {@link TermsConsumer} for the field. |
| * <li>After all fields are added, the consumer is {@link #close}d. |
| * </ol> |
| * |
| * @lucene.experimental |
| */ |
| public abstract class FieldsConsumer implements Closeable { |
| |
| /** Sole constructor. (For invocation by subclass |
| * constructors, typically implicit.) */ |
| protected FieldsConsumer() { |
| } |
| |
| /** Add a new field */ |
| public abstract TermsConsumer addField(FieldInfo field) throws IOException; |
| |
| /** Called when we are done adding everything. */ |
| @Override |
| public abstract void close() throws IOException; |
| |
| /** Called during merging to merge all {@link Fields} from |
| * sub-readers. This must recurse to merge all postings |
| * (terms, docs, positions, etc.). A {@link |
| * PostingsFormat} can override this default |
| * implementation to do its own merging. */ |
| public void merge(MergeState mergeState, Fields fields) throws IOException { |
| for (String field : fields) { |
| FieldInfo info = mergeState.fieldInfos.fieldInfo(field); |
| assert info != null : "FieldInfo for field is null: "+ field; |
| Terms terms = fields.terms(field); |
| if (terms != null) { |
| final TermsConsumer termsConsumer = addField(info); |
| termsConsumer.merge(mergeState, info.getIndexOptions(), terms.iterator(null)); |
| } |
| } |
| } |
| } |