BufferChecks.java :  » Game » Lightweight-Java-Game-Library-2.4.2 » org » lwjgl » Java Open Source

/*
 * Copyright (c) 2002-2008 LWJGL Project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'LWJGL' nor the names of
 *   its contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.lwjgl;

import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.ShortBuffer;
import java.nio.LongBuffer;

/**
 * <p>A class to check buffer boundaries in general. If there is unsufficient space
 * in the buffer when the call is made then a buffer overflow would otherwise
 * occur and cause unexpected behaviour, a crash, or worse, a security risk.
 *
 * Internal class, don't use.
 * </p>
 * @author cix_foo <cix_foo@users.sourceforge.net>
 * @author elias_naur <elias_naur@users.sourceforge.net>
 * @version $Revision: 3279 $
 * $Id: BufferChecks.java 3279 2010-03-11 21:06:49Z spasi $
 */
public class BufferChecks {
  /** Static methods only! */
  private BufferChecks() {
  }

  /**
   * Helper methods to ensure a function pointer is not-null (0)
   */
  public static void checkFunctionAddress(long pointer) {
    if (pointer == 0) {
      throw new IllegalStateException("Function is not supported");
    }
  }

  /**
   * Helper methods to ensure a ByteBuffer is null-terminated
   */
  public static void checkNullTerminated(ByteBuffer buf) {
    if (buf.get(buf.limit() - 1) != 0) {
      throw new IllegalArgumentException("Missing null termination");
    }
  }

  public static void checkNullTerminated(ByteBuffer buf, int count) {
    int nullFound = 0;
    for ( int i = buf.position(); i < buf.limit(); i++ ) {
      if ( buf.get(i) == 0 )
        nullFound++;
    }

    if ( nullFound < count )
      throw new IllegalArgumentException("Missing null termination");
  }

  /** Helper methods to ensure an IntBuffer is null-terminated */
  public static void checkNullTerminated(IntBuffer buf) {
    if ( buf.get(buf.limit() - 1) != 0 ) {
      throw new IllegalArgumentException("Missing null termination");
    }
  }

  public static void checkNotNull(Object o) {
    if (o == null)
      throw new IllegalArgumentException("Null argument");
  }

  /**
   * Helper methods to ensure a buffer is direct (and, implicitly, non-null).
   */
  public static void checkDirect(ByteBuffer buf) {
    if (!buf.isDirect()) {
      throw new IllegalArgumentException("ByteBuffer is not direct");
    }
  }

  public static void checkDirect(ShortBuffer buf) {
    if (!buf.isDirect()) {
      throw new IllegalArgumentException("ShortBuffer is not direct");
    }
  }

  public static void checkDirect(IntBuffer buf) {
    if (!buf.isDirect()) {
      throw new IllegalArgumentException("IntBuffer is not direct");
    }
  }

  public static void checkDirect(LongBuffer buf) {
    if (!buf.isDirect()) {
      throw new IllegalArgumentException("LongBuffer is not direct");
    }
  }

  public static void checkDirect(FloatBuffer buf) {
    if (!buf.isDirect()) {
      throw new IllegalArgumentException("FloatBuffer is not direct");
    }
  }

  public static void checkDirect(DoubleBuffer buf) {
    if (!buf.isDirect()) {
      throw new IllegalArgumentException("DoubleBuffer is not direct");
    }
  }

  /**
   * This is a separate call to help inline checkBufferSize.
   */
  private static void throwBufferSizeException(Buffer buf, int size) {
    throw new IllegalArgumentException("Number of remaining buffer elements is " + buf.remaining() + ", must be at least " + size);
  }

  /**
   * Helper method to ensure a buffer is big enough to receive data from a
   * glGet* operation.
   *
   * @param buf
   *            The buffer to check
   * @param size
   *         The minimum buffer size
   * @throws IllegalArgumentException
   */
  public static void checkBufferSize(Buffer buf, int size) {
    if (buf.remaining() < size) {
      throwBufferSizeException(buf, size);
    }
  }

  public static void checkBuffer(ByteBuffer buf, int size) {
    checkBufferSize(buf, size);
    checkDirect(buf);
  }

  public static void checkBuffer(ShortBuffer buf, int size) {
    checkBufferSize(buf, size);
    checkDirect(buf);
  }

  public static void checkBuffer(IntBuffer buf, int size) {
    checkBufferSize(buf, size);
    checkDirect(buf);
  }

  public static void checkBuffer(LongBuffer buf, int size) {
    checkBufferSize(buf, size);
    checkDirect(buf);
  }

  public static void checkBuffer(FloatBuffer buf, int size) {
    checkBufferSize(buf, size);
    checkDirect(buf);
  }

  public static void checkBuffer(DoubleBuffer buf, int size) {
    checkBufferSize(buf, size);
    checkDirect(buf);
  }
}