Java tutorial
/* * 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. */ package org.apache.lucene.index; import java.io.IOException; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.List; import org.apache.lucene.codecs.DocValuesProducer; import org.apache.lucene.codecs.FieldsProducer; import org.apache.lucene.codecs.NormsProducer; import org.apache.lucene.codecs.PointsReader; import org.apache.lucene.codecs.StoredFieldsReader; import org.apache.lucene.codecs.TermVectorsReader; import org.apache.lucene.util.Accountable; import org.apache.lucene.util.Accountables; import org.apache.lucene.util.FutureObjects; /** * LeafReader implemented by codec APIs. */ public abstract class CodecReader extends LeafReader implements Accountable { /** Sole constructor. (For invocation by subclass * constructors, typically implicit.) */ protected CodecReader() { } /** * Expert: retrieve thread-private StoredFieldsReader * @lucene.internal */ public abstract StoredFieldsReader getFieldsReader(); /** * Expert: retrieve thread-private TermVectorsReader * @lucene.internal */ public abstract TermVectorsReader getTermVectorsReader(); /** * Expert: retrieve underlying NormsProducer * @lucene.internal */ public abstract NormsProducer getNormsReader(); /** * Expert: retrieve underlying DocValuesProducer * @lucene.internal */ public abstract DocValuesProducer getDocValuesReader(); /** * Expert: retrieve underlying FieldsProducer * @lucene.internal */ public abstract FieldsProducer getPostingsReader(); /** * Expert: retrieve underlying PointsReader * @lucene.internal */ public abstract PointsReader getPointsReader(); @Override public final void document(int docID, StoredFieldVisitor visitor) throws IOException { checkBounds(docID); getFieldsReader().visitDocument(docID, visitor); } @Override public final Fields getTermVectors(int docID) throws IOException { TermVectorsReader termVectorsReader = getTermVectorsReader(); if (termVectorsReader == null) { return null; } checkBounds(docID); return termVectorsReader.get(docID); } private void checkBounds(int docID) { FutureObjects.checkIndex(docID, maxDoc()); } @Override public final Terms terms(String field) throws IOException { //ensureOpen(); no; getPostingsReader calls this // We could check the FieldInfo IndexOptions but there's no point since // PostingsReader will simply return null for fields that don't exist or that have no terms index. return getPostingsReader().terms(field); } // returns the FieldInfo that corresponds to the given field and type, or // null if the field does not exist, or not indexed as the requested // DovDocValuesType. private FieldInfo getDVField(String field, DocValuesType type) { FieldInfo fi = getFieldInfos().fieldInfo(field); if (fi == null) { // Field does not exist return null; } if (fi.getDocValuesType() == DocValuesType.NONE) { // Field was not indexed with doc values return null; } if (fi.getDocValuesType() != type) { // Field DocValues are different than requested type return null; } return fi; } @Override public final NumericDocValues getNumericDocValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getDVField(field, DocValuesType.NUMERIC); if (fi == null) { return null; } return getDocValuesReader().getNumeric(fi); } @Override public final BinaryDocValues getBinaryDocValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getDVField(field, DocValuesType.BINARY); if (fi == null) { return null; } return getDocValuesReader().getBinary(fi); } @Override public final SortedDocValues getSortedDocValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getDVField(field, DocValuesType.SORTED); if (fi == null) { return null; } return getDocValuesReader().getSorted(fi); } @Override public final SortedNumericDocValues getSortedNumericDocValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getDVField(field, DocValuesType.SORTED_NUMERIC); if (fi == null) { return null; } return getDocValuesReader().getSortedNumeric(fi); } @Override public final SortedSetDocValues getSortedSetDocValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getDVField(field, DocValuesType.SORTED_SET); if (fi == null) { return null; } return getDocValuesReader().getSortedSet(fi); } @Override public final NumericDocValues getNormValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getFieldInfos().fieldInfo(field); if (fi == null || fi.hasNorms() == false) { // Field does not exist or does not index norms return null; } return getNormsReader().getNorms(fi); } @Override public final PointValues getPointValues(String field) throws IOException { ensureOpen(); FieldInfo fi = getFieldInfos().fieldInfo(field); if (fi == null || fi.getPointDataDimensionCount() == 0) { // Field does not exist or does not index points return null; } return getPointsReader().getValues(field); } @Override protected void doClose() throws IOException { } @Override public long ramBytesUsed() { ensureOpen(); // terms/postings long ramBytesUsed = getPostingsReader().ramBytesUsed(); // norms if (getNormsReader() != null) { ramBytesUsed += getNormsReader().ramBytesUsed(); } // docvalues if (getDocValuesReader() != null) { ramBytesUsed += getDocValuesReader().ramBytesUsed(); } // stored fields if (getFieldsReader() != null) { ramBytesUsed += getFieldsReader().ramBytesUsed(); } // term vectors if (getTermVectorsReader() != null) { ramBytesUsed += getTermVectorsReader().ramBytesUsed(); } // points if (getPointsReader() != null) { ramBytesUsed += getPointsReader().ramBytesUsed(); } return ramBytesUsed; } @Override public Collection<Accountable> getChildResources() { ensureOpen(); final List<Accountable> resources = new ArrayList<>(6); // terms/postings resources.add(Accountables.namedAccountable("postings", getPostingsReader())); // norms if (getNormsReader() != null) { resources.add(Accountables.namedAccountable("norms", getNormsReader())); } // docvalues if (getDocValuesReader() != null) { resources.add(Accountables.namedAccountable("docvalues", getDocValuesReader())); } // stored fields if (getFieldsReader() != null) { resources.add(Accountables.namedAccountable("stored fields", getFieldsReader())); } // term vectors if (getTermVectorsReader() != null) { resources.add(Accountables.namedAccountable("term vectors", getTermVectorsReader())); } // points if (getPointsReader() != null) { resources.add(Accountables.namedAccountable("points", getPointsReader())); } return Collections.unmodifiableList(resources); } @Override public void checkIntegrity() throws IOException { ensureOpen(); // terms/postings getPostingsReader().checkIntegrity(); // norms if (getNormsReader() != null) { getNormsReader().checkIntegrity(); } // docvalues if (getDocValuesReader() != null) { getDocValuesReader().checkIntegrity(); } // stored fields if (getFieldsReader() != null) { getFieldsReader().checkIntegrity(); } // term vectors if (getTermVectorsReader() != null) { getTermVectorsReader().checkIntegrity(); } // points if (getPointsReader() != null) { getPointsReader().checkIntegrity(); } } }