| using J2N.Collections.Generic.Extensions; |
| using J2N.Threading.Atomic; |
| using System; |
| using System.Collections.Concurrent; |
| using System.Collections.Generic; |
| using System.Globalization; |
| using System.IO; |
| |
| namespace Lucene.Net.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. |
| */ |
| |
| /// <summary> |
| /// A memory-resident <see cref="Directory"/> implementation. Locking |
| /// implementation is by default the <see cref="SingleInstanceLockFactory"/> |
| /// but can be changed with <see cref="Directory.SetLockFactory(LockFactory)"/>. |
| /// |
| /// <para/><b>Warning:</b> This class is not intended to work with huge |
| /// indexes. Everything beyond several hundred megabytes will waste |
| /// resources (GC cycles), because it uses an internal buffer size |
| /// of 1024 bytes, producing millions of <see cref="T:byte[1024]"/> arrays. |
| /// This class is optimized for small memory-resident indexes. |
| /// It also has bad concurrency on multithreaded environments. |
| /// |
| /// <para/>It is recommended to materialize large indexes on disk and use |
| /// <see cref="MMapDirectory"/>, which is a high-performance directory |
| /// implementation working directly on the file system cache of the |
| /// operating system, so copying data to heap space is not useful. |
| /// </summary> |
| public class RAMDirectory : BaseDirectory |
| { |
| protected internal readonly ConcurrentDictionary<string, RAMFile> m_fileMap = new ConcurrentDictionary<string, RAMFile>(); |
| protected internal readonly AtomicInt64 m_sizeInBytes = new AtomicInt64(0); |
| |
| // ***** |
| // Lock acquisition sequence: RAMDirectory, then RAMFile |
| // ***** |
| |
| /// <summary> |
| /// Constructs an empty <see cref="Directory"/>. </summary> |
| public RAMDirectory() |
| { |
| try |
| { |
| SetLockFactory(new SingleInstanceLockFactory()); |
| } |
| catch (IOException) // LUCENENET: IDE0059: Remove unnecessary value assignment |
| { |
| // Cannot happen |
| } |
| } |
| |
| /// <summary> |
| /// Creates a new <see cref="RAMDirectory"/> instance from a different |
| /// <see cref="Directory"/> implementation. This can be used to load |
| /// a disk-based index into memory. |
| /// |
| /// <para/><b>Warning:</b> this class is not intended to work with huge |
| /// indexes. Everything beyond several hundred megabytes will waste |
| /// resources (GC cycles), because it uses an internal buffer size |
| /// of 1024 bytes, producing millions of <see cref="T:byte[1024]"/> arrays. |
| /// this class is optimized for small memory-resident indexes. |
| /// It also has bad concurrency on multithreaded environments. |
| /// |
| /// <para/>For disk-based indexes it is recommended to use |
| /// <see cref="MMapDirectory"/>, which is a high-performance directory |
| /// implementation working directly on the file system cache of the |
| /// operating system, so copying data to heap space is not useful. |
| /// |
| /// <para/>Note that the resulting <see cref="RAMDirectory"/> instance is fully |
| /// independent from the original <see cref="Directory"/> (it is a |
| /// complete copy). Any subsequent changes to the |
| /// original <see cref="Directory"/> will not be visible in the |
| /// <see cref="RAMDirectory"/> instance. |
| /// </summary> |
| /// <param name="dir"> a <see cref="Directory"/> value </param> |
| /// <param name="context">io context</param> |
| /// <exception cref="IOException"> if an error occurs </exception> |
| public RAMDirectory(Directory dir, IOContext context) |
| : this(dir, false, context) |
| { |
| } |
| |
| private RAMDirectory(Directory dir, bool closeDir, IOContext context) |
| : this() |
| { |
| foreach (string file in dir.ListAll()) |
| { |
| dir.Copy(this, file, file, context); |
| } |
| if (closeDir) |
| { |
| dir.Dispose(); |
| } |
| } |
| |
| public override string GetLockID() |
| { |
| return "lucene-" + GetHashCode().ToString("x", CultureInfo.InvariantCulture); |
| } |
| |
| public override sealed 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. |
| // LUCENENET NOTE: Just because it is broken in Java, doesn't mean we can't use it in .NET. |
| return m_fileMap.Keys.ToArray(); |
| } |
| |
| /// <summary> |
| /// Returns true iff the named file exists in this directory. </summary> |
| [Obsolete("this method will be removed in 5.0")] |
| public override sealed bool FileExists(string name) |
| { |
| EnsureOpen(); |
| return m_fileMap.ContainsKey(name); |
| } |
| |
| /// <summary> |
| /// Returns the length in bytes of a file in the directory. </summary> |
| /// <exception cref="IOException"> if the file does not exist </exception> |
| public override sealed long FileLength(string name) |
| { |
| EnsureOpen(); |
| if (!m_fileMap.TryGetValue(name, out RAMFile file) || file == null) |
| { |
| throw new FileNotFoundException(name); |
| } |
| return file.Length; |
| } |
| |
| /// <summary> |
| /// Return total size in bytes of all files in this directory. This is |
| /// currently quantized to <see cref="RAMOutputStream.BUFFER_SIZE"/>. |
| /// </summary> |
| public long GetSizeInBytes() |
| { |
| EnsureOpen(); |
| return m_sizeInBytes; |
| } |
| |
| /// <summary> |
| /// Removes an existing file in the directory. </summary> |
| /// <exception cref="IOException"> if the file does not exist </exception> |
| public override void DeleteFile(string name) |
| { |
| EnsureOpen(); |
| if (m_fileMap.TryRemove(name, out RAMFile file) && file != null) |
| { |
| file.directory = null; |
| m_sizeInBytes.AddAndGet(-file.m_sizeInBytes); |
| } |
| else |
| { |
| throw new FileNotFoundException(name); |
| } |
| } |
| |
| /// <summary> |
| /// Creates a new, empty file in the directory with the given name. Returns a stream writing this file. </summary> |
| public override IndexOutput CreateOutput(string name, IOContext context) |
| { |
| EnsureOpen(); |
| RAMFile file = NewRAMFile(); |
| if (m_fileMap.TryRemove(name, out RAMFile existing) && existing != null) |
| { |
| m_sizeInBytes.AddAndGet(-existing.m_sizeInBytes); |
| existing.directory = null; |
| } |
| m_fileMap[name] = file; |
| return new RAMOutputStream(file); |
| } |
| |
| /// <summary> |
| /// Returns a new <see cref="RAMFile"/> for storing data. this method can be |
| /// overridden to return different <see cref="RAMFile"/> impls, that e.g. override |
| /// <see cref="RAMFile.NewBuffer(int)"/>. |
| /// </summary> |
| protected virtual RAMFile NewRAMFile() |
| { |
| return new RAMFile(this); |
| } |
| |
| public override void Sync(ICollection<string> names) |
| { |
| } |
| |
| /// <summary> |
| /// Returns a stream reading an existing file. </summary> |
| public override IndexInput OpenInput(string name, IOContext context) |
| { |
| EnsureOpen(); |
| if (!m_fileMap.TryGetValue(name, out RAMFile file) || file == null) |
| { |
| throw new FileNotFoundException(name); |
| } |
| return new RAMInputStream(name, file); |
| } |
| |
| /// <summary> |
| /// Closes the store to future operations, releasing associated memory. </summary> |
| protected override void Dispose(bool disposing) |
| { |
| if (disposing) |
| { |
| IsOpen = false; |
| m_fileMap.Clear(); |
| } |
| } |
| } |
| } |