--- /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.IOException;
+import java.io.FileNotFoundException;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.lucene.index.IndexFileNameFilter;
+import org.apache.lucene.util.ThreadInterruptedException;
+
+/**
+ * A memory-resident {@link Directory} implementation. Locking
+ * implementation is by default the {@link SingleInstanceLockFactory}
+ * but can be changed with {@link #setLockFactory}.
+ */
+public class RAMDirectory extends Directory implements Serializable {
+
+ private static final long serialVersionUID = 1l;
+
+ protected final Map<String,RAMFile> fileMap = new ConcurrentHashMap<String,RAMFile>();
+ protected final AtomicLong sizeInBytes = new AtomicLong();
+
+ // *****
+ // Lock acquisition sequence: RAMDirectory, then RAMFile
+ // *****
+
+ /** Constructs an empty {@link Directory}. */
+ public RAMDirectory() {
+ try {
+ setLockFactory(new SingleInstanceLockFactory());
+ } catch (IOException e) {
+ // Cannot happen
+ }
+ }
+
+ /**
+ * Creates a new <code>RAMDirectory</code> instance from a different
+ * <code>Directory</code> implementation. This can be used to load
+ * a disk-based index into memory.
+ * <P>
+ * This should be used only with indices that can fit into memory.
+ * <P>
+ * Note that the resulting <code>RAMDirectory</code> instance is fully
+ * independent from the original <code>Directory</code> (it is a
+ * complete copy). Any subsequent changes to the
+ * original <code>Directory</code> will not be visible in the
+ * <code>RAMDirectory</code> instance.
+ *
+ * @param dir a <code>Directory</code> value
+ * @exception IOException if an error occurs
+ */
+ public RAMDirectory(Directory dir) throws IOException {
+ this(dir, false);
+ }
+
+ private RAMDirectory(Directory dir, boolean closeDir) throws IOException {
+ this();
+
+ IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
+ for (String file : dir.listAll()) {
+ if (filter.accept(null, file)) {
+ dir.copy(this, file, file);
+ }
+ }
+ if (closeDir) {
+ dir.close();
+ }
+ }
+
+ @Override
+ public final String[] listAll() {
+ ensureOpen();
+ // NOTE: fileMap.keySet().toArray(new String[0]) is broken in non Sun JDKs,
+ // and the code below is resilient to map changes during the array population.
+ Set<String> fileNames = fileMap.keySet();
+ List<String> names = new ArrayList<String>(fileNames.size());
+ for (String name : fileNames) names.add(name);
+ return names.toArray(new String[names.size()]);
+ }
+
+ /** Returns true iff the named file exists in this directory. */
+ @Override
+ public final boolean fileExists(String name) {
+ ensureOpen();
+ return fileMap.containsKey(name);
+ }
+
+ /** Returns the time the named file was last modified.
+ * @throws IOException if the file does not exist
+ */
+ @Override
+ public final long fileModified(String name) throws IOException {
+ ensureOpen();
+ RAMFile file = fileMap.get(name);
+ if (file == null) {
+ throw new FileNotFoundException(name);
+ }
+ return file.getLastModified();
+ }
+
+ /** Set the modified time of an existing file to now.
+ * @throws IOException if the file does not exist
+ * @deprecated Lucene never uses this API; it will be
+ * removed in 4.0. */
+ @Override
+ @Deprecated
+ public void touchFile(String name) throws IOException {
+ ensureOpen();
+ RAMFile file = fileMap.get(name);
+ if (file == null) {
+ throw new FileNotFoundException(name);
+ }
+
+ long ts2, ts1 = System.currentTimeMillis();
+ do {
+ try {
+ Thread.sleep(0, 1);
+ } catch (InterruptedException ie) {
+ throw new ThreadInterruptedException(ie);
+ }
+ ts2 = System.currentTimeMillis();
+ } while(ts1 == ts2);
+
+ file.setLastModified(ts2);
+ }
+
+ /** Returns the length in bytes of a file in the directory.
+ * @throws IOException if the file does not exist
+ */
+ @Override
+ public final long fileLength(String name) throws IOException {
+ ensureOpen();
+ RAMFile file = fileMap.get(name);
+ if (file == null) {
+ throw new FileNotFoundException(name);
+ }
+ return file.getLength();
+ }
+
+ /**
+ * Return total size in bytes of all files in this directory. This is
+ * currently quantized to RAMOutputStream.BUFFER_SIZE.
+ */
+ public final long sizeInBytes() {
+ ensureOpen();
+ return sizeInBytes.get();
+ }
+
+ /** Removes an existing file in the directory.
+ * @throws IOException if the file does not exist
+ */
+ @Override
+ public void deleteFile(String name) throws IOException {
+ ensureOpen();
+ RAMFile file = fileMap.remove(name);
+ if (file != null) {
+ file.directory = null;
+ sizeInBytes.addAndGet(-file.sizeInBytes);
+ } else {
+ throw new FileNotFoundException(name);
+ }
+ }
+
+ /** Creates a new, empty file in the directory with the given name. Returns a stream writing this file. */
+ @Override
+ public IndexOutput createOutput(String name) throws IOException {
+ ensureOpen();
+ RAMFile file = newRAMFile();
+ RAMFile existing = fileMap.remove(name);
+ if (existing != null) {
+ sizeInBytes.addAndGet(-existing.sizeInBytes);
+ existing.directory = null;
+ }
+ fileMap.put(name, file);
+ return new RAMOutputStream(file);
+ }
+
+ /**
+ * Returns a new {@link RAMFile} for storing data. This method can be
+ * overridden to return different {@link RAMFile} impls, that e.g. override
+ * {@link RAMFile#newBuffer(int)}.
+ */
+ protected RAMFile newRAMFile() {
+ return new RAMFile(this);
+ }
+
+ /** Returns a stream reading an existing file. */
+ @Override
+ public IndexInput openInput(String name) throws IOException {
+ ensureOpen();
+ RAMFile file = fileMap.get(name);
+ if (file == null) {
+ throw new FileNotFoundException(name);
+ }
+ return new RAMInputStream(name, file);
+ }
+
+ /** Closes the store to future operations, releasing associated memory. */
+ @Override
+ public void close() {
+ isOpen = false;
+ fileMap.clear();
+ }
+}
fnp / pylucene.git / blobdiff