+++ /dev/null
-package org.apache.lucene.store;
-
-/**
- * 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.FileNotFoundException;
-import java.io.IOException;
-import java.io.Closeable;
-import java.util.Collection;
-
-import org.apache.lucene.index.IndexFileNameFilter;
-import org.apache.lucene.util.IOUtils;
-
-/** A Directory is a flat list of files. Files may be written once, when they
- * are created. Once a file is created it may only be opened for read, or
- * deleted. Random access is permitted both when reading and writing.
- *
- * <p> Java's i/o APIs not used directly, but rather all i/o is
- * through this API. This permits things such as: <ul>
- * <li> implementation of RAM-based indices;
- * <li> implementation indices stored in a database, via JDBC;
- * <li> implementation of an index as a single file;
- * </ul>
- *
- * Directory locking is implemented by an instance of {@link
- * LockFactory}, and can be changed for each Directory
- * instance using {@link #setLockFactory}.
- *
- */
-public abstract class Directory implements Closeable {
-
- volatile protected boolean isOpen = true;
-
- /** Holds the LockFactory instance (implements locking for
- * this Directory instance). */
- protected LockFactory lockFactory;
-
- /**
- * Returns an array of strings, one for each file in the directory.
- *
- * @throws NoSuchDirectoryException if the directory is not prepared for any
- * write operations (such as {@link #createOutput(String)}).
- * @throws IOException in case of other IO errors
- */
- public abstract String[] listAll() throws IOException;
-
- /** Returns true iff a file with the given name exists. */
- public abstract boolean fileExists(String name)
- throws IOException;
-
- /** Returns the time the named file was last modified. */
- public abstract long fileModified(String name)
- throws IOException;
-
- /** Set the modified time of an existing file to now.
- *
- * @deprecated Lucene never uses this API; it will be
- * removed in 4.0. */
- @Deprecated
- public abstract void touchFile(String name)
- throws IOException;
-
- /** Removes an existing file in the directory. */
- public abstract void deleteFile(String name)
- throws IOException;
-
- /**
- * Returns the length of a file in the directory. This method follows the
- * following contract:
- * <ul>
- * <li>Throws {@link FileNotFoundException} if the file does not exist
- * <li>Returns a value ≥0 if the file exists, which specifies its length.
- * </ul>
- *
- * @param name the name of the file for which to return the length.
- * @throws FileNotFoundException if the file does not exist.
- * @throws IOException if there was an IO error while retrieving the file's
- * length.
- */
- public abstract long fileLength(String name) throws IOException;
-
-
- /** Creates a new, empty file in the directory with the given name.
- Returns a stream writing this file. */
- public abstract IndexOutput createOutput(String name)
- throws IOException;
-
- /**
- * Ensure that any writes to this file are moved to
- * stable storage. Lucene uses this to properly commit
- * changes to the index, to prevent a machine/OS crash
- * from corrupting the index.
- * @deprecated use {@link #sync(Collection)} instead.
- * For easy migration you can change your code to call
- * sync(Collections.singleton(name))
- */
- @Deprecated
- public void sync(String name) throws IOException { // TODO 4.0 kill me
- }
-
- /**
- * Ensure that any writes to these files are moved to
- * stable storage. Lucene uses this to properly commit
- * changes to the index, to prevent a machine/OS crash
- * from corrupting the index.<br/>
- * <br/>
- * NOTE: Clients may call this method for same files over
- * and over again, so some impls might optimize for that.
- * For other impls the operation can be a noop, for various
- * reasons.
- */
- public void sync(Collection<String> names) throws IOException { // TODO 4.0 make me abstract
- for (String name : names)
- sync(name);
- }
-
- /** Returns a stream reading an existing file. */
- public abstract IndexInput openInput(String name)
- throws IOException;
-
- /** Returns a stream reading an existing file, with the
- * specified read buffer size. The particular Directory
- * implementation may ignore the buffer size. Currently
- * the only Directory implementations that respect this
- * parameter are {@link FSDirectory} and {@link
- * org.apache.lucene.index.CompoundFileReader}.
- */
- public IndexInput openInput(String name, int bufferSize) throws IOException {
- return openInput(name);
- }
-
- /** Construct a {@link Lock}.
- * @param name the name of the lock file
- */
- public Lock makeLock(String name) {
- return lockFactory.makeLock(name);
- }
- /**
- * Attempt to clear (forcefully unlock and remove) the
- * specified lock. Only call this at a time when you are
- * certain this lock is no longer in use.
- * @param name name of the lock to be cleared.
- */
- public void clearLock(String name) throws IOException {
- if (lockFactory != null) {
- lockFactory.clearLock(name);
- }
- }
-
- /** Closes the store. */
- public abstract void close()
- throws IOException;
-
- /**
- * Set the LockFactory that this Directory instance should
- * use for its locking implementation. Each * instance of
- * LockFactory should only be used for one directory (ie,
- * do not share a single instance across multiple
- * Directories).
- *
- * @param lockFactory instance of {@link LockFactory}.
- */
- public void setLockFactory(LockFactory lockFactory) throws IOException {
- assert lockFactory != null;
- this.lockFactory = lockFactory;
- lockFactory.setLockPrefix(this.getLockID());
- }
-
- /**
- * Get the LockFactory that this Directory instance is
- * using for its locking implementation. Note that this
- * may be null for Directory implementations that provide
- * their own locking implementation.
- */
- public LockFactory getLockFactory() {
- return this.lockFactory;
- }
-
- /**
- * Return a string identifier that uniquely differentiates
- * this Directory instance from other Directory instances.
- * This ID should be the same if two Directory instances
- * (even in different JVMs and/or on different machines)
- * are considered "the same index". This is how locking
- * "scopes" to the right index.
- */
- public String getLockID() {
- return this.toString();
- }
-
- @Override
- public String toString() {
- return super.toString() + " lockFactory=" + getLockFactory();
- }
-
- /**
- * Copies the file <i>src</i> to {@link Directory} <i>to</i> under the new
- * file name <i>dest</i>.
- * <p>
- * If you want to copy the entire source directory to the destination one, you
- * can do so like this:
- *
- * <pre>
- * Directory to; // the directory to copy to
- * for (String file : dir.listAll()) {
- * dir.copy(to, file, newFile); // newFile can be either file, or a new name
- * }
- * </pre>
- * <p>
- * <b>NOTE:</b> this method does not check whether <i>dest<i> exist and will
- * overwrite it if it does.
- */
- public void copy(Directory to, String src, String dest) throws IOException {
- IndexOutput os = null;
- IndexInput is = null;
- IOException priorException = null;
- try {
- os = to.createOutput(dest);
- is = openInput(src);
- is.copyBytes(os, is.length());
- } catch (IOException ioe) {
- priorException = ioe;
- } finally {
- IOUtils.closeWhileHandlingException(priorException, os, is);
- }
- }
-
- /**
- * Copy contents of a directory src to a directory dest. If a file in src
- * already exists in dest then the one in dest will be blindly overwritten.
- * <p>
- * <b>NOTE:</b> the source directory cannot change while this method is
- * running. Otherwise the results are undefined and you could easily hit a
- * FileNotFoundException.
- * <p>
- * <b>NOTE:</b> this method only copies files that look like index files (ie,
- * have extensions matching the known extensions of index files).
- *
- * @param src source directory
- * @param dest destination directory
- * @param closeDirSrc if <code>true</code>, call {@link #close()} method on
- * source directory
- * @deprecated should be replaced with calls to
- * {@link #copy(Directory, String, String)} for every file that
- * needs copying. You can use the following code:
- *
- * <pre>
- * IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
- * for (String file : src.listAll()) {
- * if (filter.accept(null, file)) {
- * src.copy(dest, file, file);
- * }
- * }
- * </pre>
- */
- @Deprecated
- public static void copy(Directory src, Directory dest, boolean closeDirSrc) throws IOException {
- IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
- for (String file : src.listAll()) {
- if (filter.accept(null, file)) {
- src.copy(dest, file, file);
- }
- }
- if (closeDirSrc) {
- src.close();
- }
- }
-
- /**
- * @throws AlreadyClosedException if this Directory is closed
- */
- protected final void ensureOpen() throws AlreadyClosedException {
- if (!isOpen)
- throw new AlreadyClosedException("this Directory is closed");
- }
-}
fnp / pylucene.git / blobdiff