Lucene example source code file (RAMFile.java)

This example Lucene source code file (RAMFile.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

arraylist, arraylist, io, ramdirectory, ramdirectory, ramfile, ramfile, serializable, serializable, util

The Lucene RAMFile.java source code

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.util.ArrayList;
import java.io.Serializable;

/** @lucene.internal */
public class RAMFile implements Serializable {

  private static final long serialVersionUID = 1l;

  protected ArrayList<byte[]> buffers = new ArrayList();
  long length;
  RAMDirectory directory;
  protected long sizeInBytes;

  // This is publicly modifiable via Directory.touchFile(), so direct access not supported
  private long lastModified = System.currentTimeMillis();

  // File used as buffer, in no RAMDirectory
  protected RAMFile() {}
  
  RAMFile(RAMDirectory directory) {
    this.directory = directory;
  }

  // For non-stream access from thread that might be concurrent with writing
  public synchronized long getLength() {
    return length;
  }

  protected synchronized void setLength(long length) {
    this.length = length;
  }

  // For non-stream access from thread that might be concurrent with writing
  public synchronized long getLastModified() {
    return lastModified;
  }

  protected synchronized void setLastModified(long lastModified) {
    this.lastModified = lastModified;
  }

  protected final byte[] addBuffer(int size) {
    byte[] buffer = newBuffer(size);
    synchronized(this) {
      buffers.add(buffer);
      sizeInBytes += size;
    }

    if (directory != null) {
      directory.sizeInBytes.getAndAdd(size);
    }
    return buffer;
  }

  protected final synchronized byte[] getBuffer(int index) {
    return buffers.get(index);
  }

  protected final synchronized int numBuffers() {
    return buffers.size();
  }

  /**
   * Expert: allocate a new buffer. 
   * Subclasses can allocate differently. 
   * @param size size of allocated buffer.
   * @return allocated buffer.
   */
  protected byte[] newBuffer(int size) {
    return new byte[size];
  }

  public synchronized long getSizeInBytes() {
    return sizeInBytes;
  }
  
}