content: /*******************************************************************************
   * Copyright (c) 2009, 2019 Mountainminds GmbH & Co. KG and Contributors
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *    Marc R. Hoffmann - initial API and implementation
   *    
   *******************************************************************************/
  package org.jacoco.core.internal.data;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  /**
   * Additional data output methods for compact storage of data structures.
   * 
   * @see CompactDataInput
   */
  public class CompactDataOutput extends DataOutputStream {
  
  	/**
  	 * Creates a new {@link CompactDataOutput} instance that writes data to the
  	 * specified underlying output stream
  	 * 
  	 * @param out
  	 *            underlying output stream
  	 */
  	public CompactDataOutput(final OutputStream out) {
  		super(out);
  	}
  
  	/**
  	 * Writes a variable length representation of an integer value that reduces
  	 * the number of written bytes for small positive values. Depending on the
  	 * given value 1 to 5 bytes will be written to the underlying stream.
  	 * 
  	 * @param value
  	 *            value to write
  	 * @throws IOException
  	 *             if thrown by the underlying stream
  	 */
  	public void writeVarInt(final int value) throws IOException {
  		if ((value & 0xFFFFFF80) == 0) {
  			writeByte(value);
  		} else {
  			writeByte(0x80 | (value & 0x7F));
  			writeVarInt(value >>> 7);
  		}
  	}
  
  	/**
  	 * Writes a boolean array. Internally a sequence of boolean values is packed
  	 * into single bits.
  	 * 
  	 * @param value
  	 *            boolean array
  	 * @throws IOException
  	 *             if thrown by the underlying stream
  	 */
  	public void writeBooleanArray(final boolean[] value) throws IOException {
  		writeVarInt(value.length);
  		int buffer = 0;
  		int bufferSize = 0;
  		for (final boolean b : value) {
  			if (b) {
  				buffer |= 0x01 << bufferSize;
  			}
  			if (++bufferSize == 8) {
  				writeByte(buffer);
  				buffer = 0;
  				bufferSize = 0;
  			}
  		}
  		if (bufferSize > 0) {
  			writeByte(buffer);
  		}
  	}
  
  }
  