package org.apache.blur.utils;
/*
* 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.HashSet;
import java.util.Set;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FieldType;
import org.apache.lucene.document.StoredField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.FieldInfo;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.StoredFieldVisitor;
/**
* A {@link StoredFieldVisitor} that creates a {@link Document} containing all
* stored fields, or only specific requested fields provided to
* {@link #DocumentStoredFieldVisitor(Set)}.
* <p>
* This is used by {@link IndexReader#document(int)} to load a document.
*
* @lucene.experimental
*/
public class ResetableDocumentStoredFieldVisitor extends StoredFieldVisitor {
private static final int _emptyDocumentSize;
private static final int _integerFieldSize;
private static final int _longFieldSize;
private static final int _doubleFieldSize;
private static final int _floatFieldSize;
private static final int _emptyString;
private static final int _emptyByteArrayFieldSize;
static {
_emptyDocumentSize = (int) RamUsageEstimator.sizeOf(new Document());
_integerFieldSize = (int) RamUsageEstimator.sizeOf(new StoredField("", 0));
_longFieldSize = (int) RamUsageEstimator.sizeOf(new StoredField("", 0l));
_doubleFieldSize = (int) RamUsageEstimator.sizeOf(new StoredField("", 0.0));
_floatFieldSize = (int) RamUsageEstimator.sizeOf(new StoredField("", 0.0f));
_emptyByteArrayFieldSize = (int) RamUsageEstimator.sizeOf(new StoredField("", new byte[] {}));
_emptyString = (int) RamUsageEstimator.sizeOf("");
}
private Document doc = new Document();
private final Set<String> fieldsToAdd;
private int size = _emptyDocumentSize;
/** Load only fields named in the provided <code>Set<String></code>. */
public ResetableDocumentStoredFieldVisitor(Set<String> fieldsToAdd) {
this.fieldsToAdd = fieldsToAdd;
}
/** Load only fields named in the provided <code>Set<String></code>. */
public ResetableDocumentStoredFieldVisitor(String... fields) {
fieldsToAdd = new HashSet<String>(fields.length);
for (String field : fields) {
fieldsToAdd.add(field);
}
}
/** Load all stored fields. */
public ResetableDocumentStoredFieldVisitor() {
this.fieldsToAdd = null;
}
@Override
public void binaryField(FieldInfo fieldInfo, byte[] value) throws IOException {
doc.add(new StoredField(fieldInfo.name, value));
addSize(fieldInfo, _emptyByteArrayFieldSize);
size += value.length;
}
@Override
public void stringField(FieldInfo fieldInfo, String value) throws IOException {
final FieldType ft = new FieldType(TextField.TYPE_STORED);
ft.setStoreTermVectors(fieldInfo.hasVectors());
ft.setIndexed(fieldInfo.isIndexed());
ft.setOmitNorms(fieldInfo.omitsNorms());
ft.setIndexOptions(fieldInfo.getIndexOptions());
doc.add(new Field(fieldInfo.name, value, ft));
size += _emptyString * 2;
size += fieldInfo.name.length() * 2;
size += value.length() * 2;
}
@Override
public void intField(FieldInfo fieldInfo, int value) {
doc.add(new StoredField(fieldInfo.name, value));
addSize(fieldInfo, _integerFieldSize);
}
@Override
public void longField(FieldInfo fieldInfo, long value) {
doc.add(new StoredField(fieldInfo.name, value));
addSize(fieldInfo, _longFieldSize);
}
@Override
public void floatField(FieldInfo fieldInfo, float value) {
doc.add(new StoredField(fieldInfo.name, value));
addSize(fieldInfo, _floatFieldSize);
}
@Override
public void doubleField(FieldInfo fieldInfo, double value) {
doc.add(new StoredField(fieldInfo.name, value));
addSize(fieldInfo, _doubleFieldSize);
}
private void addSize(FieldInfo fieldInfo, int fieldSize) {
size += fieldSize;
size += _emptyString;
size += fieldInfo.name.length() * 2;
}
@Override
public Status needsField(FieldInfo fieldInfo) throws IOException {
return fieldsToAdd == null || fieldsToAdd.contains(fieldInfo.name) ? Status.YES : Status.NO;
}
/**
* Retrieve the visited document.
*
* @return Document populated with stored fields. Note that only the stored
* information in the field instances is valid, data such as boosts,
* indexing options, term vector options, etc is not set.
*/
public Document getDocument() {
return doc;
}
public int getSize() {
return size;
}
public void reset() {
doc = new Document();
size = _emptyDocumentSize;
}
}