libjava/java/nio/FloatBuffer.java

/* FloatBuffer.java -- 
   Copyright (C) 2002, 2003 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
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package java.nio;

/**
 * @since 1.4
 */
public abstract class FloatBuffer extends Buffer
  implements Comparable
{
  int array_offset;
  float[] backing_buffer;

  FloatBuffer (int capacity, int limit, int position, int mark)
  {
    super (capacity, limit, position, mark);
    array_offset = 0;
  }

  FloatBuffer (float[] buffer, int offset, int capacity, int limit, int position, int mark)
  {
    super (capacity, limit, position, mark);
    this.backing_buffer = buffer;
    this.array_offset = offset;
  }

  /**
   * Allocates a new <code>FloatBuffer</code> object with a given capacity.
   */
  public static FloatBuffer allocate (int capacity)
  {
    return new FloatBufferImpl (capacity);
  }

  /**
   * Wraps a <code>float</code> array into a <code>FloatBuffer</code>
   * object.
   *
   * @exception IndexOutOfBoundsException If the preconditions on the offset
   * and length parameters do not hold
   */
  final public static FloatBuffer wrap (float[] array, int offset, int length)
  {
    return new FloatBufferImpl (array, 0, array.length, offset + length, offset, -1, false);
  }

  /**
   * Wraps a <code>float</code> array into a <code>FloatBuffer</code>
   * object.
   */
  final public static FloatBuffer wrap (float[] array)
  {
    return wrap (array, 0, array.length);
  }
  
  /**
   * This method transfers <code>floats<code> from this buffer into the given
   * destination array.
   *
   * @param dst The destination array
   * @param offset The offset within the array of the first <code>float</code>
   * to be written; must be non-negative and no larger than dst.length.
   * @param length The maximum number of bytes to be written to the given array;
   * must be non-negative and no larger than dst.length - offset.
   *
   * @exception BufferUnderflowException If there are fewer than length
   * <code>floats</code> remaining in this buffer.
   * @exception IndexOutOfBoundsException If the preconditions on the offset
   * and length parameters do not hold.
   */
  public FloatBuffer get (float[] dst, int offset, int length)
  {
    for (int i = offset; i < offset + length; i++)
      {
        dst [i] = get ();
      }

    return this;
  }

  /**
   * This method transfers <code>floats<code> from this buffer into the given
   * destination array.
   *
   * @param dst The byte array to write into.
   *
   * @exception BufferUnderflowException If there are fewer than dst.length
   * <code>floats</code> remaining in this buffer.
   */
  public FloatBuffer get (float[] dst)
  {
    return get (dst, 0, dst.length);
  }

  /**
   * Writes the content of the the <code>FloatBUFFER</code> src
   * into the buffer.
   *
   * @param src The source data.
   *
   * @exception BufferOverflowException If there is insufficient space in this
   * buffer for the remaining <code>floats<code> in the source buffer.
   * @exception IllegalArgumentException If the source buffer is this buffer.
   * @exception ReadOnlyBufferException If this buffer is read-only.
   */
  public FloatBuffer put (FloatBuffer src)
  {
    if (src == this)
      throw new IllegalArgumentException ();

    if (src.remaining () > remaining ())
      throw new BufferOverflowException ();

    if (src.remaining () > 0)
      {
        float[] toPut = new float [src.remaining ()];
        src.get (toPut);
        src.put (toPut);
      }

    return this;
  }

  /**
   * Writes the content of the the <code>float array</code> src
   * into the buffer.
   *
   * @param src The array to copy into the buffer.
   * @param offset The offset within the array of the first byte to be read;
   * must be non-negative and no larger than src.length.
   * @param length The number of bytes to be read from the given array;
   * must be non-negative and no larger than src.length - offset.
   * 
   * @exception BufferOverflowException If there is insufficient space in this
   * buffer for the remaining <code>floats<code> in the source array.
   * @exception IndexOutOfBoundsException If the preconditions on the offset
   * and length parameters do not hold
   * @exception ReadOnlyBufferException If this buffer is read-only.
   */
  public FloatBuffer put (float[] src, int offset, int length)
  {
    for (int i = offset; i < offset + length; i++)
      put (src [i]);

    return this;
  }

  /**
   * Writes the content of the the <code>float array</code> src
   * into the buffer.
   *
   * @param src The array to copy into the buffer.
   * 
   * @exception BufferOverflowException If there is insufficient space in this
   * buffer for the remaining <code>floats<code> in the source array.
   * @exception ReadOnlyBufferException If this buffer is read-only.
   */
  public final FloatBuffer put (float[] src)
  {
    return put (src, 0, src.length);
  }

  /**
   * Tells whether ot not this buffer is backed by an accessible
   * <code>float</code> array.
   */
  public final boolean hasArray ()
  {
    return (backing_buffer != null
            && !isReadOnly ());
  }

  /**
   * Returns the <code>float</code> array that backs this buffer.
   *
   * @exception ReadOnlyBufferException If this buffer is read-only.
   * @exception UnsupportedOperationException If this buffer is not backed
   * by an accessible array.
   */
  public final float[] array ()
  {
    if (backing_buffer == null)
      throw new UnsupportedOperationException ();

    if (isReadOnly ())
      throw new ReadOnlyBufferException ();
    
    return backing_buffer;
  }

  /**
   * Returns the offset within this buffer's backing array of the first element.
   *
   * @exception ReadOnlyBufferException If this buffer is read-only.
   * @exception UnsupportedOperationException If this buffer is not backed
   * by an accessible array.
   */
  public final int arrayOffset ()
  {
    if (backing_buffer == null)
      throw new UnsupportedOperationException ();

    if (isReadOnly ())
      throw new ReadOnlyBufferException ();
    
    return array_offset;
  }

  /**
   * Calculates a hash code for this buffer.
   */
  public int hashCode ()
  {
    // FIXME: Check what SUN calculates here.
    return super.hashCode ();
  }

  /**
   * Checks if this buffer is equal to obj.
   */
  public boolean equals (Object obj)
  {
    if (obj instanceof FloatBuffer)
      {
        return compareTo (obj) == 0;
      }

    return false;
  }

  /**
   * Compares two <code>FloatBuffer</code> objects.
   *
   * @exception ClassCastException If obj is not an object derived from
   * <code>FloatBuffer</code>.
   */
  public int compareTo (Object obj)
  {
    FloatBuffer a = (FloatBuffer) obj;

    if (a.remaining () != remaining ())
      return 1;

    if (! hasArray () ||
        ! a.hasArray ())
      {
        return 1;
      }

    int r = remaining ();
    int i1 = position ();
    int i2 = a.position ();

    for (int i = 0; i < r; i++)
      {
        int t = (int) (get (i1) - a.get (i2));

        if (t != 0)
          {
            return (int) t;
          }
      }

    return 0;
  }

  /**
   * Returns the byte order of this buffer.
   */
  public abstract ByteOrder order ();

  /**
   * Reads the <code>float</code> at this buffer's current position,
   * and then increments the position.
   *
   * @exception BufferUnderflowException If there are no remaining
   * <code>floats</code> in this buffer.
   */
  public abstract float get ();

  /**
   * Writes the <code>float</code> at this buffer's current position,
   * and then increments the position.
   *
   * @exception BufferOverflowException If there no remaining 
   * <code>floats</code> in this buffer.
   * @exception ReadOnlyBufferException If this buffer is read-only.
   */
  public abstract FloatBuffer put (float b);

  /**
   * Absolute get method.
   *
   * @exception IndexOutOfBoundsException If index is negative or not smaller
   * than the buffer's limit.
   */
  public abstract float get (int index);
  
  /**
   * Absolute put method.
   *
   * @exception IndexOutOfBoundsException If index is negative or not smaller
   * than the buffer's limit.
   * @exception ReadOnlyBufferException If this buffer is read-only.
   */
  public abstract FloatBuffer put (int index, float b);

  /**
   * Compacts this buffer.
   * 
   * @exception ReadOnlyBufferException If this buffer is read-only.
   */
  public abstract FloatBuffer compact ();

  /**
   * Tells wether or not this buffer is direct.
   */
  public abstract boolean isDirect ();

  /**
   * Creates a new <code>FloatBuffer</code> whose content is a shared
   * subsequence of this buffer's content.
   */
  public abstract FloatBuffer slice ();

  /**
   * Creates a new <code>FloatBuffer</code> that shares this buffer's
   * content.
   */
  public abstract FloatBuffer duplicate ();

  /**
   * Creates a new read-only <code>FloatBuffer</code> that shares this
   * buffer's content.
   */
  public abstract FloatBuffer asReadOnlyBuffer ();
}