+++ /dev/null
-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.store.Directory;
-import org.apache.lucene.store.IndexOutput;
-import org.apache.lucene.store.IndexInput;
-import org.apache.lucene.util.IOUtils;
-
-import java.util.LinkedList;
-import java.util.HashSet;
-
-import java.io.IOException;
-
-/**
- * Combines multiple files into a single compound file.
- * The file format:<br>
- * <ul>
- * <li>VInt fileCount</li>
- * <li>{Directory}
- * fileCount entries with the following structure:</li>
- * <ul>
- * <li>long dataOffset</li>
- * <li>String fileName</li>
- * </ul>
- * <li>{File Data}
- * fileCount entries with the raw data of the corresponding file</li>
- * </ul>
- *
- * The fileCount integer indicates how many files are contained in this compound
- * file. The {directory} that follows has that many entries. Each directory entry
- * contains a long pointer to the start of this file's data section, and a String
- * with that file's name.
- *
- * @lucene.internal
- */
-public final class CompoundFileWriter {
-
- private static final class FileEntry {
- /** source file */
- String file;
-
- /** temporary holder for the start of directory entry for this file */
- long directoryOffset;
-
- /** temporary holder for the start of this file's data section */
- long dataOffset;
-
- /** the directory which contains the file. */
- Directory dir;
- }
-
- // Before versioning started.
- static final int FORMAT_PRE_VERSION = 0;
-
- // Segment name is not written in the file names.
- static final int FORMAT_NO_SEGMENT_PREFIX = -1;
-
- // NOTE: if you introduce a new format, make it 1 lower
- // than the current one, and always change this if you
- // switch to a new format!
- static final int FORMAT_CURRENT = FORMAT_NO_SEGMENT_PREFIX;
-
- private Directory directory;
- private String fileName;
- private HashSet<String> ids;
- private LinkedList<FileEntry> entries;
- private boolean merged = false;
- private SegmentMerger.CheckAbort checkAbort;
-
- /** Create the compound stream in the specified file. The file name is the
- * entire name (no extensions are added).
- * @throws NullPointerException if <code>dir</code> or <code>name</code> is null
- */
- public CompoundFileWriter(Directory dir, String name) {
- this(dir, name, null);
- }
-
- CompoundFileWriter(Directory dir, String name, SegmentMerger.CheckAbort checkAbort) {
- if (dir == null)
- throw new NullPointerException("directory cannot be null");
- if (name == null)
- throw new NullPointerException("name cannot be null");
- this.checkAbort = checkAbort;
- directory = dir;
- fileName = name;
- ids = new HashSet<String>();
- entries = new LinkedList<FileEntry>();
- }
-
- /** Returns the directory of the compound file. */
- public Directory getDirectory() {
- return directory;
- }
-
- /** Returns the name of the compound file. */
- public String getName() {
- return fileName;
- }
-
- /** Add a source stream. <code>file</code> is the string by which the
- * sub-stream will be known in the compound stream.
- *
- * @throws IllegalStateException if this writer is closed
- * @throws NullPointerException if <code>file</code> is null
- * @throws IllegalArgumentException if a file with the same name
- * has been added already
- */
- public void addFile(String file) {
- addFile(file, directory);
- }
-
- /**
- * Same as {@link #addFile(String)}, only for files that are found in an
- * external {@link Directory}.
- */
- public void addFile(String file, Directory dir) {
- if (merged)
- throw new IllegalStateException(
- "Can't add extensions after merge has been called");
-
- if (file == null)
- throw new NullPointerException(
- "file cannot be null");
-
- if (! ids.add(file))
- throw new IllegalArgumentException(
- "File " + file + " already added");
-
- FileEntry entry = new FileEntry();
- entry.file = file;
- entry.dir = dir;
- entries.add(entry);
- }
-
- /** Merge files with the extensions added up to now.
- * All files with these extensions are combined sequentially into the
- * compound stream.
- * @throws IllegalStateException if close() had been called before or
- * if no file has been added to this object
- */
- public void close() throws IOException {
- if (merged)
- throw new IllegalStateException("Merge already performed");
-
- if (entries.isEmpty())
- throw new IllegalStateException("No entries to merge have been defined");
-
- merged = true;
-
- // open the compound stream
- IndexOutput os = directory.createOutput(fileName);
- IOException priorException = null;
- try {
- // Write the Version info - must be a VInt because CFR reads a VInt
- // in older versions!
- os.writeVInt(FORMAT_CURRENT);
-
- // Write the number of entries
- os.writeVInt(entries.size());
-
- // Write the directory with all offsets at 0.
- // Remember the positions of directory entries so that we can
- // adjust the offsets later
- long totalSize = 0;
- for (FileEntry fe : entries) {
- fe.directoryOffset = os.getFilePointer();
- os.writeLong(0); // for now
- os.writeString(IndexFileNames.stripSegmentName(fe.file));
- totalSize += fe.dir.fileLength(fe.file);
- }
-
- // Pre-allocate size of file as optimization --
- // this can potentially help IO performance as
- // we write the file and also later during
- // searching. It also uncovers a disk-full
- // situation earlier and hopefully without
- // actually filling disk to 100%:
- final long finalLength = totalSize+os.getFilePointer();
- os.setLength(finalLength);
-
- // Open the files and copy their data into the stream.
- // Remember the locations of each file's data section.
- for (FileEntry fe : entries) {
- fe.dataOffset = os.getFilePointer();
- copyFile(fe, os);
- }
-
- // Write the data offsets into the directory of the compound stream
- for (FileEntry fe : entries) {
- os.seek(fe.directoryOffset);
- os.writeLong(fe.dataOffset);
- }
-
- assert finalLength == os.length();
-
- // Close the output stream. Set the os to null before trying to
- // close so that if an exception occurs during the close, the
- // finally clause below will not attempt to close the stream
- // the second time.
- IndexOutput tmp = os;
- os = null;
- tmp.close();
- } catch (IOException e) {
- priorException = e;
- } finally {
- IOUtils.closeWhileHandlingException(priorException, os);
- }
- }
-
- /**
- * Copy the contents of the file with specified extension into the provided
- * output stream.
- */
- private void copyFile(FileEntry source, IndexOutput os) throws IOException {
- IndexInput is = source.dir.openInput(source.file);
- try {
- long startPtr = os.getFilePointer();
- long length = is.length();
- os.copyBytes(is, length);
-
- if (checkAbort != null) {
- checkAbort.work(length);
- }
-
- // Verify that the output length diff is equal to original file
- long endPtr = os.getFilePointer();
- long diff = endPtr - startPtr;
- if (diff != length)
- throw new IOException("Difference in the output file offsets " + diff
- + " does not match the original file length " + length);
-
- } finally {
- is.close();
- }
- }
-}
fnp / pylucene.git / blobdiff