package org.apache.lucene.codecs.simpletext;
/*
* 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.codecs.StoredFieldsReader;
import org.apache.lucene.index.FieldInfo;
import org.apache.lucene.index.FieldInfos;
import org.apache.lucene.index.IndexFileNames;
import org.apache.lucene.index.SegmentInfo;
import org.apache.lucene.index.StoredFieldVisitor;
import org.apache.lucene.store.AlreadyClosedException;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.IOContext;
import org.apache.lucene.store.IndexInput;
import org.apache.lucene.util.ArrayUtil;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.CharsRef;
import org.apache.lucene.util.IOUtils;
import org.apache.lucene.util.StringHelper;
import org.apache.lucene.util.UnicodeUtil;
import static org.apache.lucene.codecs.simpletext.SimpleTextStoredFieldsWriter.*;
/**
* reads plaintext stored fields
* <p>
* <b><font color="red">FOR RECREATIONAL USE ONLY</font></B>
* @lucene.experimental
*/
public class SimpleTextStoredFieldsReader extends StoredFieldsReader {
private long offsets[]; /* docid -> offset in .fld file */
private IndexInput in;
private BytesRef scratch = new BytesRef();
private CharsRef scratchUTF16 = new CharsRef();
private final FieldInfos fieldInfos;
public SimpleTextStoredFieldsReader(Directory directory, SegmentInfo si, FieldInfos fn, IOContext context) throws IOException {
this.fieldInfos = fn;
boolean success = false;
try {
in = directory.openInput(IndexFileNames.segmentFileName(si.name, "", SimpleTextStoredFieldsWriter.FIELDS_EXTENSION), context);
success = true;
} finally {
if (!success) {
try {
close();
} catch (Throwable t) {} // ensure we throw our original exception
}
}
readIndex(si.getDocCount());
}
// used by clone
SimpleTextStoredFieldsReader(long offsets[], IndexInput in, FieldInfos fieldInfos) {
this.offsets = offsets;
this.in = in;
this.fieldInfos = fieldInfos;
}
// we don't actually write a .fdx-like index, instead we read the
// stored fields file in entirety up-front and save the offsets
// so we can seek to the documents later.
private void readIndex(int size) throws IOException {
offsets = new long[size];
int upto = 0;
while (!scratch.equals(END)) {
readLine();
if (StringHelper.startsWith(scratch, DOC)) {
offsets[upto] = in.getFilePointer();
upto++;
}
}
assert upto == offsets.length;
}
@Override
public void visitDocument(int n, StoredFieldVisitor visitor) throws IOException {
in.seek(offsets[n]);
readLine();
assert StringHelper.startsWith(scratch, NUM);
int numFields = parseIntAt(NUM.length);
for (int i = 0; i < numFields; i++) {
readLine();
assert StringHelper.startsWith(scratch, FIELD);
int fieldNumber = parseIntAt(FIELD.length);
FieldInfo fieldInfo = fieldInfos.fieldInfo(fieldNumber);
readLine();
assert StringHelper.startsWith(scratch, NAME);
readLine();
assert StringHelper.startsWith(scratch, TYPE);
final BytesRef type;
if (equalsAt(TYPE_STRING, scratch, TYPE.length)) {
type = TYPE_STRING;
} else if (equalsAt(TYPE_BINARY, scratch, TYPE.length)) {
type = TYPE_BINARY;
} else if (equalsAt(TYPE_INT, scratch, TYPE.length)) {
type = TYPE_INT;
} else if (equalsAt(TYPE_LONG, scratch, TYPE.length)) {
type = TYPE_LONG;
} else if (equalsAt(TYPE_FLOAT, scratch, TYPE.length)) {
type = TYPE_FLOAT;
} else if (equalsAt(TYPE_DOUBLE, scratch, TYPE.length)) {
type = TYPE_DOUBLE;
} else {
throw new RuntimeException("unknown field type");
}
switch (visitor.needsField(fieldInfo)) {
case YES:
readField(type, fieldInfo, visitor);
break;
case NO:
readLine();
assert StringHelper.startsWith(scratch, VALUE);
break;
case STOP: return;
}
}
}
private void readField(BytesRef type, FieldInfo fieldInfo, StoredFieldVisitor visitor) throws IOException {
readLine();
assert StringHelper.startsWith(scratch, VALUE);
if (type == TYPE_STRING) {
visitor.stringField(fieldInfo, new String(scratch.bytes, scratch.offset+VALUE.length, scratch.length-VALUE.length, "UTF-8"));
} else if (type == TYPE_BINARY) {
byte[] copy = new byte[scratch.length-VALUE.length];
System.arraycopy(scratch.bytes, scratch.offset+VALUE.length, copy, 0, copy.length);
visitor.binaryField(fieldInfo, copy);
} else if (type == TYPE_INT) {
UnicodeUtil.UTF8toUTF16(scratch.bytes, scratch.offset+VALUE.length, scratch.length-VALUE.length, scratchUTF16);
visitor.intField(fieldInfo, Integer.parseInt(scratchUTF16.toString()));
} else if (type == TYPE_LONG) {
UnicodeUtil.UTF8toUTF16(scratch.bytes, scratch.offset+VALUE.length, scratch.length-VALUE.length, scratchUTF16);
visitor.longField(fieldInfo, Long.parseLong(scratchUTF16.toString()));
} else if (type == TYPE_FLOAT) {
UnicodeUtil.UTF8toUTF16(scratch.bytes, scratch.offset+VALUE.length, scratch.length-VALUE.length, scratchUTF16);
visitor.floatField(fieldInfo, Float.parseFloat(scratchUTF16.toString()));
} else if (type == TYPE_DOUBLE) {
UnicodeUtil.UTF8toUTF16(scratch.bytes, scratch.offset+VALUE.length, scratch.length-VALUE.length, scratchUTF16);
visitor.doubleField(fieldInfo, Double.parseDouble(scratchUTF16.toString()));
}
}
@Override
public StoredFieldsReader clone() {
if (in == null) {
throw new AlreadyClosedException("this FieldsReader is closed");
}
return new SimpleTextStoredFieldsReader(offsets, in.clone(), fieldInfos);
}
@Override
public void close() throws IOException {
try {
IOUtils.close(in);
} finally {
in = null;
offsets = null;
}
}
private void readLine() throws IOException {
SimpleTextUtil.readLine(in, scratch);
}
private int parseIntAt(int offset) {
UnicodeUtil.UTF8toUTF16(scratch.bytes, scratch.offset+offset, scratch.length-offset, scratchUTF16);
return ArrayUtil.parseInt(scratchUTF16.chars, 0, scratchUTF16.length);
}
private boolean equalsAt(BytesRef a, BytesRef b, int bOffset) {
return a.length == b.length - bOffset &&
ArrayUtil.equals(a.bytes, a.offset, b.bytes, b.offset + bOffset, b.length - bOffset);
}
@Override
public long ramBytesUsed() {
return 0;
}
}