Lucene example source code file (StreamUtils.java)

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Java - Lucene tags/keywords

buffer_size, compressorexception, fileoutputstream, inputstream, inputstream, io, ioexception, ioexception, outputstream, override, override, plain, string, type, type, util

The Lucene StreamUtils.java source code

package org.apache.lucene.benchmark.byTask.utils;

/**
 * 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.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import org.apache.commons.compress.compressors.CompressorException;
import org.apache.commons.compress.compressors.CompressorStreamFactory;

/**
 * Stream utilities.
 */
public class StreamUtils {

	/** Buffer size used across the benchmark package */
	public static final int BUFFER_SIZE = 1 << 16; // 64K
	
	/** File format type */
	public enum Type {
		/** BZIP2 is automatically used for <b>.bz2 and .bzip2 extensions. */
		BZIP2(CompressorStreamFactory.BZIP2),
		/** GZIP is automatically used for <b>.gz and .gzip extensions. */
		GZIP(CompressorStreamFactory.GZIP),
		/** Plain text is used for anything which is not GZIP or BZIP. */
		PLAIN(null);
		private final String csfType;
		Type(String csfType) {
			this.csfType = csfType;
		}
		private InputStream inputStream(InputStream in) throws IOException {
			try {
				return csfType==null ? in : closableCompressorInputStream(this, in);
			} catch (CompressorException e) {
    		IOException ioe = new IOException(e.getMessage());
    		ioe.initCause(e);
    		throw ioe;			}  
		}
		private OutputStream outputStream(OutputStream os) throws IOException {
			try {
				return csfType==null ? os : new CompressorStreamFactory().createCompressorOutputStream(csfType, os);
			} catch (CompressorException e) {
				IOException ioe = new IOException(e.getMessage());
				ioe.initCause(e);
				throw ioe;  
			}  
		}
	}
	
  private static final Map<String,Type> extensionToType = new HashMap();
  static {
  	// these in are lower case, we will lower case at the test as well
    extensionToType.put(".bz2", Type.BZIP2);
    extensionToType.put(".bzip", Type.BZIP2);
    extensionToType.put(".gz", Type.GZIP);
    extensionToType.put(".gzip", Type.GZIP);
  }
  
  
  /**
   * Returns an {@link InputStream} over the requested file. This method
   * attempts to identify the appropriate {@link InputStream} instance to return
   * based on the file name (e.g., if it ends with .bz2 or .bzip, return a
   * 'bzip' {@link InputStream}).
   */
  public static InputStream inputStream(File file) throws IOException {
    // First, create a FileInputStream, as this will be required by all types.
    // Wrap with BufferedInputStream for better performance
    InputStream in = new BufferedInputStream(new FileInputStream(file), BUFFER_SIZE);
    return fileType(file).inputStream(in);
  }

  /** Return the type of the file, or null if unknown */
  private static Type fileType(File file) {
  	Type type = null;
    String fileName = file.getName();
    int idx = fileName.lastIndexOf('.');
    if (idx != -1) {
      type = extensionToType.get(fileName.substring(idx).toLowerCase(Locale.ENGLISH));
    }
    return type==null ? Type.PLAIN : type;
	}
  
  /**
   * Wrap the compressor input stream so that calling close will also close
   * the underlying stream - workaround for CommonsCompress bug (COMPRESS-127). 
   */
  private static InputStream closableCompressorInputStream(Type type, final InputStream is) throws CompressorException {
    final InputStream delegee = new CompressorStreamFactory().createCompressorInputStream(type.csfType, is);
    if (!Type.GZIP.equals(type)) {
      return delegee; //compressor bug affects only gzip
    }
    return new InputStream() {
			@Override	public int read() throws IOException { return delegee.read();	}
			@Override	public int read(byte[] b) throws IOException { return delegee.read(b);	}
			@Override	public int available() throws IOException {	return delegee.available();	}
			@Override	public synchronized void mark(int readlimit) { delegee.mark(readlimit);	}
			@Override	public boolean markSupported() { return delegee.markSupported(); }
			@Override	public int read(byte[] b, int off, int len) throws IOException { return delegee.read(b, off, len); }
			@Override	public synchronized void reset() throws IOException {	delegee.reset(); }
			@Override	public long skip(long n) throws IOException {	return delegee.skip(n);	}
			@Override	
			public void close() throws IOException { 
				delegee.close();
				is.close();
			}
    };
	}

  /**
   * Returns an {@link OutputStream} over the requested file, identifying
   * the appropriate {@link OutputStream} instance similar to {@link #inputStream(File)}.
   */
  public static OutputStream outputStream(File file) throws IOException {
    // First, create a FileInputStream, as this will be required by all types.
    // Wrap with BufferedInputStream for better performance
    OutputStream os = new BufferedOutputStream(new FileOutputStream(file), BUFFER_SIZE);
    return fileType(file).outputStream(os);
  }
}