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 org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.document.AbstractField;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FieldSelector;
import org.apache.lucene.document.FieldSelectorResult;
import org.apache.lucene.document.Fieldable;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.IndexInput;
import org.apache.lucene.store.AlreadyClosedException;
import org.apache.lucene.store.BufferedIndexInput;
import org.apache.lucene.util.CloseableThreadLocal;
import java.io.IOException;
import java.io.Reader;
/**
* Class responsible for access to stored document fields.
* <p/>
* It uses <segment>.fdt and <segment>.fdx; files.
*/
final class FieldsReader implements Cloneable {
private final static int FORMAT_SIZE = 4;
private final FieldInfos fieldInfos;
// The main fieldStream, used only for cloning.
private final IndexInput cloneableFieldsStream;
// This is a clone of cloneableFieldsStream used for reading documents.
// It should not be cloned outside of a synchronized context.
private final IndexInput fieldsStream;
private final IndexInput cloneableIndexStream;
private final IndexInput indexStream;
private int numTotalDocs;
private int size;
private boolean closed;
private final int format;
// The docID offset where our docs begin in the index
// file. This will be 0 if we have our own private file.
private int docStoreOffset;
private CloseableThreadLocal<IndexInput> fieldsStreamTL = new CloseableThreadLocal<IndexInput>();
private boolean isOriginal = false;
/** Returns a cloned FieldsReader that shares open
* IndexInputs with the original one. It is the caller's
* job not to close the original FieldsReader until all
* clones are called (eg, currently SegmentReader manages
* this logic). */
@Override
public Object clone() {
ensureOpen();
return new FieldsReader(fieldInfos, numTotalDocs, size, format, docStoreOffset, cloneableFieldsStream, cloneableIndexStream);
}
// Used only by clone
private FieldsReader(FieldInfos fieldInfos, int numTotalDocs, int size, int format, int docStoreOffset,
IndexInput cloneableFieldsStream, IndexInput cloneableIndexStream) {
this.fieldInfos = fieldInfos;
this.numTotalDocs = numTotalDocs;
this.size = size;
this.format = format;
this.docStoreOffset = docStoreOffset;
this.cloneableFieldsStream = cloneableFieldsStream;
this.cloneableIndexStream = cloneableIndexStream;
fieldsStream = (IndexInput) cloneableFieldsStream.clone();
indexStream = (IndexInput) cloneableIndexStream.clone();
}
FieldsReader(Directory d, String segment, FieldInfos fn) throws IOException {
this(d, segment, fn, BufferedIndexInput.BUFFER_SIZE, -1, 0);
}
FieldsReader(Directory d, String segment, FieldInfos fn, int readBufferSize, int docStoreOffset, int size) throws IOException {
boolean success = false;
isOriginal = true;
try {
fieldInfos = fn;
cloneableFieldsStream = d.openInput(IndexFileNames.segmentFileName(segment, "", IndexFileNames.FIELDS_EXTENSION), readBufferSize);
final String indexStreamFN = IndexFileNames.segmentFileName(segment, "", IndexFileNames.FIELDS_INDEX_EXTENSION);
cloneableIndexStream = d.openInput(indexStreamFN, readBufferSize);
format = cloneableIndexStream.readInt();
if (format < FieldsWriter.FORMAT_MINIMUM)
throw new IndexFormatTooOldException(indexStreamFN, format, FieldsWriter.FORMAT_MINIMUM, FieldsWriter.FORMAT_CURRENT);
if (format > FieldsWriter.FORMAT_CURRENT)
throw new IndexFormatTooNewException(indexStreamFN, format, FieldsWriter.FORMAT_MINIMUM, FieldsWriter.FORMAT_CURRENT);
fieldsStream = (IndexInput) cloneableFieldsStream.clone();
final long indexSize = cloneableIndexStream.length() - FORMAT_SIZE;
if (docStoreOffset != -1) {
// We read only a slice out of this shared fields file
this.docStoreOffset = docStoreOffset;
this.size = size;
// Verify the file is long enough to hold all of our
// docs
assert ((int) (indexSize / 8)) >= size + this.docStoreOffset: "indexSize=" + indexSize + " size=" + size + " docStoreOffset=" + docStoreOffset;
} else {
this.docStoreOffset = 0;
this.size = (int) (indexSize >> 3);
}
indexStream = (IndexInput) cloneableIndexStream.clone();
numTotalDocs = (int) (indexSize >> 3);
success = true;
} finally {
// With lock-less commits, it's entirely possible (and
// fine) to hit a FileNotFound exception above. In
// this case, we want to explicitly close any subset
// of things that were opened so that we don't have to
// wait for a GC to do so.
if (!success) {
close();
}
}
}
/**
* @throws AlreadyClosedException if this FieldsReader is closed
*/
private void ensureOpen() throws AlreadyClosedException {
if (closed) {
throw new AlreadyClosedException("this FieldsReader is closed");
}
}
/**
* Closes the underlying {@link org.apache.lucene.store.IndexInput} streams, including any ones associated with a
* lazy implementation of a Field. This means that the Fields values will not be accessible.
*
* @throws IOException
*/
final void close() throws IOException {
if (!closed) {
if (fieldsStream != null) {
fieldsStream.close();
}
if (isOriginal) {
if (cloneableFieldsStream != null) {
cloneableFieldsStream.close();
}
if (cloneableIndexStream != null) {
cloneableIndexStream.close();
}
}
if (indexStream != null) {
indexStream.close();
}
fieldsStreamTL.close();
closed = true;
}
}
final int size() {
return size;
}
private void seekIndex(int docID) throws IOException {
indexStream.seek(FORMAT_SIZE + (docID + docStoreOffset) * 8L);
}
final Document doc(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException {
seekIndex(n);
long position = indexStream.readLong();
fieldsStream.seek(position);
Document doc = new Document();
int numFields = fieldsStream.readVInt();
for (int i = 0; i < numFields; i++) {
int fieldNumber = fieldsStream.readVInt();
FieldInfo fi = fieldInfos.fieldInfo(fieldNumber);
FieldSelectorResult acceptField = fieldSelector == null ? FieldSelectorResult.LOAD : fieldSelector.accept(fi.name);
byte bits = fieldsStream.readByte();
assert bits <= FieldsWriter.FIELD_IS_TOKENIZED + FieldsWriter.FIELD_IS_BINARY;
boolean tokenize = (bits & FieldsWriter.FIELD_IS_TOKENIZED) != 0;
boolean binary = (bits & FieldsWriter.FIELD_IS_BINARY) != 0;
//TODO: Find an alternative approach here if this list continues to grow beyond the
//list of 5 or 6 currently here. See Lucene 762 for discussion
if (acceptField.equals(FieldSelectorResult.LOAD)) {
addField(doc, fi, binary, tokenize);
}
else if (acceptField.equals(FieldSelectorResult.LOAD_AND_BREAK)){
addField(doc, fi, binary, tokenize);
break;//Get out of this loop
}
else if (acceptField.equals(FieldSelectorResult.LAZY_LOAD)) {
addFieldLazy(doc, fi, binary, tokenize, true);
}
else if (acceptField.equals(FieldSelectorResult.LATENT)) {
addFieldLazy(doc, fi, binary, tokenize, false);
}
else if (acceptField.equals(FieldSelectorResult.SIZE)){
skipField(addFieldSize(doc, fi, binary));
}
else if (acceptField.equals(FieldSelectorResult.SIZE_AND_BREAK)){
addFieldSize(doc, fi, binary);
break;
}
else {
skipField();
}
}
return doc;
}
/** Returns the length in bytes of each raw document in a
* contiguous range of length numDocs starting with
* startDocID. Returns the IndexInput (the fieldStream),
* already seeked to the starting point for startDocID.*/
final IndexInput rawDocs(int[] lengths, int startDocID, int numDocs) throws IOException {
seekIndex(startDocID);
long startOffset = indexStream.readLong();
long lastOffset = startOffset;
int count = 0;
while (count < numDocs) {
final long offset;
final int docID = docStoreOffset + startDocID + count + 1;
assert docID <= numTotalDocs;
if (docID < numTotalDocs)
offset = indexStream.readLong();
else
offset = fieldsStream.length();
lengths[count++] = (int) (offset-lastOffset);
lastOffset = offset;
}
fieldsStream.seek(startOffset);
return fieldsStream;
}
/**
* Skip the field. We still have to read some of the information about the field, but can skip past the actual content.
* This will have the most payoff on large fields.
*/
private void skipField() throws IOException {
skipField(fieldsStream.readVInt());
}
private void skipField(int toRead) throws IOException {
fieldsStream.seek(fieldsStream.getFilePointer() + toRead);
}
private void addFieldLazy(Document doc, FieldInfo fi, boolean binary, boolean tokenize, boolean cacheResult) throws IOException {
if (binary) {
int toRead = fieldsStream.readVInt();
long pointer = fieldsStream.getFilePointer();
//was: doc.add(new Fieldable(fi.name, b, Fieldable.Store.YES));
doc.add(new LazyField(fi.name, Field.Store.YES, toRead, pointer, binary, cacheResult));
//Need to move the pointer ahead by toRead positions
fieldsStream.seek(pointer + toRead);
} else {
Field.Store store = Field.Store.YES;
Field.Index index = Field.Index.toIndex(fi.isIndexed, tokenize);
Field.TermVector termVector = Field.TermVector.toTermVector(fi.storeTermVector, fi.storeOffsetWithTermVector, fi.storePositionWithTermVector);
AbstractField f;
int length = fieldsStream.readVInt();
long pointer = fieldsStream.getFilePointer();
//Skip ahead of where we are by the length of what is stored
fieldsStream.seek(pointer+length);
f = new LazyField(fi.name, store, index, termVector, length, pointer, binary, cacheResult);
f.setOmitNorms(fi.omitNorms);
f.setOmitTermFreqAndPositions(fi.omitTermFreqAndPositions);
doc.add(f);
}
}
private void addField(Document doc, FieldInfo fi, boolean binary, boolean tokenize) throws CorruptIndexException, IOException {
if (binary) {
int toRead = fieldsStream.readVInt();
final byte[] b = new byte[toRead];
fieldsStream.readBytes(b, 0, b.length);
doc.add(new Field(fi.name, b));
} else {
Field.Store store = Field.Store.YES;
Field.Index index = Field.Index.toIndex(fi.isIndexed, tokenize);
Field.TermVector termVector = Field.TermVector.toTermVector(fi.storeTermVector, fi.storeOffsetWithTermVector, fi.storePositionWithTermVector);
AbstractField f;
f = new Field(fi.name, // name
false,
fieldsStream.readString(), // read value
store,
index,
termVector);
f.setOmitTermFreqAndPositions(fi.omitTermFreqAndPositions);
f.setOmitNorms(fi.omitNorms);
doc.add(f);
}
}
// Add the size of field as a byte[] containing the 4 bytes of the integer byte size (high order byte first; char = 2 bytes)
// Read just the size -- caller must skip the field content to continue reading fields
// Return the size in bytes or chars, depending on field type
private int addFieldSize(Document doc, FieldInfo fi, boolean binary) throws IOException {
int size = fieldsStream.readVInt(), bytesize = binary ? size : 2*size;
byte[] sizebytes = new byte[4];
sizebytes[0] = (byte) (bytesize>>>24);
sizebytes[1] = (byte) (bytesize>>>16);
sizebytes[2] = (byte) (bytesize>>> 8);
sizebytes[3] = (byte) bytesize ;
doc.add(new Field(fi.name, sizebytes));
return size;
}
/**
* A Lazy implementation of Fieldable that differs loading of fields until asked for, instead of when the Document is
* loaded.
*/
private class LazyField extends AbstractField implements Fieldable {
private int toRead;
private long pointer;
private final boolean cacheResult;
public LazyField(String name, Field.Store store, int toRead, long pointer, boolean isBinary, boolean cacheResult) {
super(name, store, Field.Index.NO, Field.TermVector.NO);
this.toRead = toRead;
this.pointer = pointer;
this.isBinary = isBinary;
this.cacheResult = cacheResult;
if (isBinary)
binaryLength = toRead;
lazy = true;
}
public LazyField(String name, Field.Store store, Field.Index index, Field.TermVector termVector, int toRead, long pointer, boolean isBinary, boolean cacheResult) {
super(name, store, index, termVector);
this.toRead = toRead;
this.pointer = pointer;
this.isBinary = isBinary;
this.cacheResult = cacheResult;
if (isBinary)
binaryLength = toRead;
lazy = true;
}
private IndexInput getFieldStream() {
IndexInput localFieldsStream = fieldsStreamTL.get();
if (localFieldsStream == null) {
localFieldsStream = (IndexInput) cloneableFieldsStream.clone();
fieldsStreamTL.set(localFieldsStream);
}
return localFieldsStream;
}
/** The value of the field as a Reader, or null. If null, the String value,
* binary value, or TokenStream value is used. Exactly one of stringValue(),
* readerValue(), getBinaryValue(), and tokenStreamValue() must be set. */
public Reader readerValue() {
ensureOpen();
return null;
}
/** The value of the field as a TokenStream, or null. If null, the Reader value,
* String value, or binary value is used. Exactly one of stringValue(),
* readerValue(), getBinaryValue(), and tokenStreamValue() must be set. */
public TokenStream tokenStreamValue() {
ensureOpen();
return null;
}
/** The value of the field as a String, or null. If null, the Reader value,
* binary value, or TokenStream value is used. Exactly one of stringValue(),
* readerValue(), getBinaryValue(), and tokenStreamValue() must be set. */
public String stringValue() {
ensureOpen();
if (isBinary)
return null;
else {
if (fieldsData == null) {
String result = null;
IndexInput localFieldsStream = getFieldStream();
try {
localFieldsStream.seek(pointer);
byte[] bytes = new byte[toRead];
localFieldsStream.readBytes(bytes, 0, toRead);
result = new String(bytes, "UTF-8");
} catch (IOException e) {
throw new FieldReaderException(e);
}
if (cacheResult == true){
fieldsData = result;
}
return result;
} else {
return (String) fieldsData;
}
}
}
@Override
public byte[] getBinaryValue(byte[] result) {
ensureOpen();
if (isBinary) {
if (fieldsData == null) {
// Allocate new buffer if result is null or too small
final byte[] b;
if (result == null || result.length < toRead)
b = new byte[toRead];
else
b = result;
IndexInput localFieldsStream = getFieldStream();
// Throw this IOException since IndexReader.document does so anyway, so probably not that big of a change for people
// since they are already handling this exception when getting the document
try {
localFieldsStream.seek(pointer);
localFieldsStream.readBytes(b, 0, toRead);
} catch (IOException e) {
throw new FieldReaderException(e);
}
binaryOffset = 0;
binaryLength = toRead;
if (cacheResult == true){
fieldsData = b;
}
return b;
} else {
return (byte[]) fieldsData;
}
} else
return null;
}
}
}