/*
* Copyright (c) 2002-2010 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.lang.reflect.Method;
import java.nio.*;
/**
* This class is a container for architecture independent pointer data.
* The interface mirrors the NIO LongBuffer API for convenience.
*
* @author Spasi
*/
public class PointerBuffer implements Comparable {
private static final boolean is64Bit;
static {
// Use reflection so that we can compile this class for the Generator.
boolean is64 = false;
try {
Method m = Class.forName("org.lwjgl.Sys").getDeclaredMethod("is64Bit", (Class[])null);
is64 = (Boolean)m.invoke(null, (Object[])null);
} catch (Throwable t) {
// ignore
} finally {
is64Bit = is64;
}
}
protected final ByteBuffer pointers;
protected final Buffer view;
protected final IntBuffer view32;
protected final LongBuffer view64;
/**
* Creates a new PointerBuffer with the specified capacity.
*
* @param capacity the PointerBuffer size, in number of pointers
*/
public PointerBuffer(final int capacity) {
this(BufferUtils.createByteBuffer(capacity * getPointerSize()));
}
/**
* Creates a new PointerBuffer using the specified ByteBuffer as its pointer
* data source. This is useful for users that do their own memory management
* over a big ByteBuffer, instead of allocating many small ones.
*
* @param source the source buffer
*/
public PointerBuffer(final ByteBuffer source) {
if ( LWJGLUtil.CHECKS )
checkSource(source);
pointers = source.slice().order(source.order());
if ( is64Bit ) {
view32 = null;
view = view64 = pointers.asLongBuffer();
} else {
view = view32 = pointers.asIntBuffer();
view64 = null;
}
}
private static void checkSource(final ByteBuffer source) {
if ( !source.isDirect() )
throw new IllegalArgumentException("The source buffer is not direct.");
final int alignment = is64Bit ? 8 : 4;
if ( (MemoryUtil.getAddress0(source) + source.position()) % alignment != 0 || source.remaining() % alignment != 0 )
throw new IllegalArgumentException("The source buffer is not aligned to " + alignment + " bytes.");
}
/**
* Returns the ByteBuffer that backs this PointerBuffer.
*
* @return the pointer ByteBuffer
*/
public ByteBuffer getBuffer() {
return pointers;
}
/** Returns true if the underlying architecture is 64bit. */
public static boolean is64Bit() {
return is64Bit;
}
/**
* Returns the pointer size in bytes, based on the underlying architecture.
*
* @return The pointer size in bytes
*/
public static int getPointerSize() {
return is64Bit ? 8 : 4;
}
/**
* Returns this buffer's capacity. </p>
*
* @return The capacity of this buffer
*/
public final int capacity() {
return view.capacity();
}
/**
* Returns this buffer's position. </p>
*
* @return The position of this buffer
*/
public final int position() {
return view.position();
}
/**
* Returns this buffer's position, in bytes. </p>
*
* @return The position of this buffer in bytes.
*/
public final int positionByte() {
return position() * getPointerSize();
}
/**
* Sets this buffer's position. If the mark is defined and larger than the
* new position then it is discarded. </p>
*
* @param newPosition The new position value; must be non-negative
* and no larger than the current limit
*
* @return This buffer
*
* @throws IllegalArgumentException If the preconditions on <tt>newPosition</tt> do not hold
*/
public final PointerBuffer position(int newPosition) {
view.position(newPosition);
return this;
}
/**
* Returns this buffer's limit. </p>
*
* @return The limit of this buffer
*/
public final int limit() {
return view.limit();
}
/**
* Sets this buffer's limit. If the position is larger than the new limit
* then it is set to the new limit. If the mark is defined and larger than
* the new limit then it is discarded. </p>
*
* @param newLimit The new limit value; must be non-negative
* and no larger than this buffer's capacity
*
* @return This buffer
*
* @throws IllegalArgumentException If the preconditions on <tt>newLimit</tt> do not hold
*/
public final PointerBuffer limit(int newLimit) {
view.limit(newLimit);
return this;
}
/**
* Sets this buffer's mark at its position. </p>
*
* @return This buffer
*/
public final PointerBuffer mark() {
view.mark();
return this;
}
/**
* Resets this buffer's position to the previously-marked position.
* <p/>
* <p> Invoking this method neither changes nor discards the mark's
* value. </p>
*
* @return This buffer
*
* @throws java.nio.InvalidMarkException If the mark has not been set
*/
public final PointerBuffer reset() {
view.reset();
return this;
}
/**
* Clears this buffer. The position is set to zero, the limit is set to
* the capacity, and the mark is discarded.
* <p/>
* <p> Invoke this method before using a sequence of channel-read or
* <i>put</i> operations to fill this buffer. For example:
* <p/>
* <blockquote><pre>
* buf.clear(); // Prepare buffer for reading
* in.read(buf); // Read data</pre></blockquote>
* <p/>
* <p> This method does not actually erase the data in the buffer, but it
* is named as if it did because it will most often be used in situations
* in which that might as well be the case. </p>
*
* @return This buffer
*/
public final PointerBuffer clear() {
view.clear();
return this;
}
/**
* Flips this buffer. The limit is set to the current position and then
* the position is set to zero. If the mark is defined then it is
* discarded.
* <p/>
* <p> After a sequence of channel-read or <i>put</i> operations, invoke
* this method to prepare for a sequence of channel-write or relative
* <i>get</i> operations. For example:
* <p/>
* <blockquote><pre>
* buf.put(magic); // Prepend header
* in.read(buf); // Read data into rest of buffer
* buf.flip(); // Flip buffer
* out.write(buf); // Write header + data to channel</pre></blockquote>
* <p/>
* <p> This method is often used in conjunction with the {@link
* java.nio.ByteBuffer#compact compact} method when transferring data from
* one place to another. </p>
*
* @return This buffer
*/
public final PointerBuffer flip() {
view.flip();
return this;
}
/**
* Rewinds this buffer. The position is set to zero and the mark is
* discarded.
* <p/>
* <p> Invoke this method before a sequence of channel-write or <i>get</i>
* operations, assuming that the limit has already been set
* appropriately. For example:
* <p/>
* <blockquote><pre>
* out.write(buf); // Write remaining data
* buf.rewind(); // Rewind buffer
* buf.get(array); // Copy data into array</pre></blockquote>
*
* @return This buffer
*/
public final PointerBuffer rewind() {
view.rewind();
return this;
}
/**
* Returns the number of elements between the current position and the
* limit. </p>
*
* @return The number of elements remaining in this buffer
*/
public final int remaining() {
return view.remaining();
}
/**
* Returns the number of bytes between the current position and the
* limit. </p>
*
* @return The number of bytes remaining in this buffer
*/
public final int remainingByte() {
return remaining() * getPointerSize();
}
/**
* Tells whether there are any elements between the current position and
* the limit. </p>
*
* @return <tt>true</tt> if, and only if, there is at least one element
* remaining in this buffer
*/
public final boolean hasRemaining() {
return view.hasRemaining();
}
/**
* Allocates a new pointer buffer.
* <p/>
* <p> The new buffer's position will be zero, its limit will be its
* capacity, and its mark will be undefined. </p>
*
* @param capacity The new buffer's capacity, in pointers
*
* @return The new pointer buffer
*
* @throws IllegalArgumentException If the <tt>capacity</tt> is a negative integer
*/
public static PointerBuffer allocateDirect(int capacity) {
return new PointerBuffer(capacity);
}
/**
* This method is used in slice and duplicate instead of normal object construction,
* so that subclasses can return themselves.
*
* @param source
*
* @return A new PointerBuffer instance
*/
protected PointerBuffer newInstance(final ByteBuffer source) {
return new PointerBuffer(source);
}
/**
* Creates a new pointer buffer whose content is a shared subsequence of
* this buffer's content.
* <p/>
* <p> The content of the new buffer will start at this buffer's current
* position. Changes to this buffer's content will be visible in the new
* buffer, and vice versa; the two buffers' position, limit, and mark
* values will be independent.
* <p/>
* <p> The new buffer's position will be zero, its capacity and its limit
* will be the number of longs remaining in this buffer, and its mark
* will be undefined. The new buffer will be direct if, and only if, this
* buffer is direct, and it will be read-only if, and only if, this buffer
* is read-only. </p>
*
* @return The new pointer buffer
*/
public PointerBuffer slice() {
final int pointerSize = getPointerSize();
pointers.position(view.position() * pointerSize);
pointers.limit(view.limit() * pointerSize);
try {
// We're slicing in the constructor.
return newInstance(pointers);
} finally {
pointers.clear();
}
}
/**
* Creates a new pointer buffer that shares this buffer's content.
* <p/>
* <p> The content of the new buffer will be that of this buffer. Changes
* to this buffer's content will be visible in the new buffer, and vice
* versa; the two buffers' position, limit, and mark values will be
* independent.
* <p/>
* <p> The new buffer's capacity, limit and position will be
* identical to those of this buffer. The new buffer will be direct if,
* and only if, this buffer is direct, and it will be read-only if, and
* only if, this buffer is read-only. </p>
*
* @return The new pointer buffer
*/
public PointerBuffer duplicate() {
final PointerBuffer buffer = newInstance(pointers);
buffer.position(view.position());
buffer.limit(view.limit());
return buffer;
}
/**
* Creates a new, read-only pointer buffer that shares this buffer's
* content.
* <p/>
* <p> The content of the new buffer will be that of this buffer. Changes
* to this buffer's content will be visible in the new buffer; the new
* buffer itself, however, will be read-only and will not allow the shared
* content to be modified. The two buffers' position, limit, and mark
* values will be independent.
* <p/>
* <p> The new buffer's capacity, limit and position will be
* identical to those of this buffer.
* <p/>
* <p> If this buffer is itself read-only then this method behaves in
* exactly the same way as the {@link #duplicate duplicate} method. </p>
*
* @return The new, read-only pointer buffer
*/
public PointerBuffer asReadOnlyBuffer() {
final PointerBuffer buffer = new PointerBufferR(pointers);
buffer.position(view.position());
buffer.limit(view.limit());
return buffer;
}
public boolean isReadOnly() {
return false;
}
/**
* Relative <i>get</i> method. Reads the long at this buffer's
* current position, and then increments the position. </p>
*
* @return The long at the buffer's current position
*
* @throws BufferUnderflowException If the buffer's current position is not smaller than its limit
*/
public long get() {
if ( is64Bit )
return view64.get();
else
return view32.get() & 0x00000000FFFFFFFFL;
}
/**
* Relative <i>put</i> method <i>(optional operation)</i>.
* <p/>
* <p> Writes the given long into this buffer at the current
* position, and then increments the position. </p>
*
* @param l The long to be written
*
* @return This buffer
*
* @throws BufferOverflowException If this buffer's current position is not smaller than its limit
* @throws ReadOnlyBufferException If this buffer is read-only
*/
public PointerBuffer put(long l) {
if ( is64Bit )
view64.put(l);
else
view32.put((int)l);
return this;
}
/**
* Convenience put that accepts PointerWrapper objects.
*
* @see #put(long)
*/
public PointerBuffer put(final PointerWrapper pointer) {
return put(pointer.getPointer());
}
/**
* Convenience put on a target ByteBuffer.
*
* @param target the target ByteBuffer
* @param l the long value to be written
*/
public static void put(final ByteBuffer target, long l) {
if ( is64Bit )
target.putLong(l);
else
target.putInt((int)l);
}
/**
* Absolute <i>get</i> method. Reads the long at the given
* index. </p>
*
* @param index The index from which the long will be read
*
* @return The long at the given index
*
* @throws IndexOutOfBoundsException If <tt>index</tt> is negative
* or not smaller than the buffer's limit
*/
public long get(int index) {
if ( is64Bit )
return view64.get(index);
else
return view32.get(index) & 0x00000000FFFFFFFFL;
}
/**
* Absolute <i>put</i> method <i>(optional operation)</i>.
* <p/>
* <p> Writes the given long into this buffer at the given
* index. </p>
*
* @param index The index at which the long will be written
* @param l The long value to be written
*
* @return This buffer
*
* @throws IndexOutOfBoundsException If <tt>index</tt> is negative
* or not smaller than the buffer's limit
* @throws ReadOnlyBufferException If this buffer is read-only
*/
public PointerBuffer put(int index, long l) {
if ( is64Bit )
view64.put(index, l);
else
view32.put(index, (int)l);
return this;
}
/**
* Convenience put that accepts PointerWrapper objects.
*
* @see #put(int, long)
*/
public PointerBuffer put(int index, PointerWrapper pointer) {
return put(index, pointer.getPointer());
}
/**
* Convenience put on a target ByteBuffer.
*
* @param target the target ByteBuffer
* @param index the index at which the long will be written
* @param l the long value to be written
*/
public static void put(final ByteBuffer target, int index, long l) {
if ( is64Bit )
target.putLong(index, l);
else
target.putInt(index, (int)l);
}
// -- Bulk get operations --
/**
* Relative bulk <i>get</i> method.
* <p/>
* <p> This method transfers longs from this buffer into the given
* destination array. If there are fewer longs remaining in the
* buffer than are required to satisfy the request, that is, if
* <tt>length</tt> <tt>></tt> <tt>remaining()</tt>, then no
* longs are transferred and a {@link BufferUnderflowException} is
* thrown.
* <p/>
* <p> Otherwise, this method copies <tt>length</tt> longs from this
* buffer into the given array, starting at the current position of this
* buffer and at the given offset in the array. The position of this
* buffer is then incremented by <tt>length</tt>.
* <p/>
* <p> In other words, an invocation of this method of the form
* <tt>src.get(dst, off, len)</tt> has exactly the same effect as
* the loop
* <p/>
* <pre>
* for (int i = off; i < off + len; i++)
* dst[i] = src.get(); </pre>
* <p/>
* except that it first checks that there are sufficient longs in
* this buffer and it is potentially much more efficient. </p>
*
* @param dst The array into which longs are to be written
* @param offset The offset within the array of the first long to be
* written; must be non-negative and no larger than
* <tt>dst.length</tt>
* @param length The maximum number of longs to be written to the given
* array; must be non-negative and no larger than
* <tt>dst.length - offset</tt>
*
* @return This buffer
*
* @throws BufferUnderflowException If there are fewer than <tt>length</tt> longs
* remaining in this buffer
* @throws IndexOutOfBoundsException If the preconditions on the <tt>offset</tt> and <tt>length</tt>
* parameters do not hold
*/
public PointerBuffer get(long[] dst, int offset, int length) {
if ( is64Bit )
view64.get(dst, offset, length);
else {
checkBounds(offset, length, dst.length);
if ( length > view32.remaining() )
throw new BufferUnderflowException();
int end = offset + length;
for ( int i = offset; i < end; i++ )
dst[i] = view32.get() & 0x00000000FFFFFFFFL;
}
return this;
}
/**
* Relative bulk <i>get</i> method.
* <p/>
* <p> This method transfers longs from this buffer into the given
* destination array. An invocation of this method of the form
* <tt>src.get(a)</tt> behaves in exactly the same way as the invocation
* <p/>
* <pre>
* src.get(a, 0, a.length) </pre>
*
* @return This buffer
*
* @throws BufferUnderflowException If there are fewer than <tt>length</tt> longs
* remaining in this buffer
*/
public PointerBuffer get(long[] dst) {
return get(dst, 0, dst.length);
}
/**
* Relative bulk <i>put</i> method <i>(optional operation)</i>.
* <p/>
* <p> This method transfers the longs remaining in the given source
* buffer into this buffer. If there are more longs remaining in the
* source buffer than in this buffer, that is, if
* <tt>src.remaining()</tt> <tt>></tt> <tt>remaining()</tt>,
* then no longs are transferred and a {@link
* BufferOverflowException} is thrown.
* <p/>
* <p> Otherwise, this method copies
* <i>n</i> = <tt>src.remaining()</tt> longs from the given
* buffer into this buffer, starting at each buffer's current position.
* The positions of both buffers are then incremented by <i>n</i>.
* <p/>
* <p> In other words, an invocation of this method of the form
* <tt>dst.put(src)</tt> has exactly the same effect as the loop
* <p/>
* <pre>
* while (src.hasRemaining())
* dst.put(src.get()); </pre>
* <p/>
* except that it first checks that there is sufficient space in this
* buffer and it is potentially much more efficient. </p>
*
* @param src The source buffer from which longs are to be read;
* must not be this buffer
*
* @return This buffer
*
* @throws BufferOverflowException If there is insufficient space in this buffer
* for the remaining longs in the source buffer
* @throws IllegalArgumentException If the source buffer is this buffer
* @throws ReadOnlyBufferException If this buffer is read-only
*/
public PointerBuffer put(PointerBuffer src) {
if ( is64Bit )
view64.put(src.view64);
else
view32.put(src.view32);
return this;
}
/**
* Relative bulk <i>put</i> method <i>(optional operation)</i>.
* <p/>
* <p> This method transfers longs into this buffer from the given
* source array. If there are more longs to be copied from the array
* than remain in this buffer, that is, if
* <tt>length</tt> <tt>></tt> <tt>remaining()</tt>, then no
* longs are transferred and a {@link BufferOverflowException} is
* thrown.
* <p/>
* <p> Otherwise, this method copies <tt>length</tt> longs from the
* given array into this buffer, starting at the given offset in the array
* and at the current position of this buffer. The position of this buffer
* is then incremented by <tt>length</tt>.
* <p/>
* <p> In other words, an invocation of this method of the form
* <tt>dst.put(src, off, len)</tt> has exactly the same effect as
* the loop
* <p/>
* <pre>
* for (int i = off; i < off + len; i++)
* dst.put(a[i]); </pre>
* <p/>
* except that it first checks that there is sufficient space in this
* buffer and it is potentially much more efficient. </p>
*
* @param src The array from which longs are to be read
* @param offset The offset within the array of the first long to be read;
* must be non-negative and no larger than <tt>array.length</tt>
* @param length The number of longs to be read from the given array;
* must be non-negative and no larger than
* <tt>array.length - offset</tt>
*
* @return This buffer
*
* @throws BufferOverflowException If there is insufficient space in this buffer
* @throws IndexOutOfBoundsException If the preconditions on the <tt>offset</tt> and <tt>length</tt>
* parameters do not hold
* @throws ReadOnlyBufferException If this buffer is read-only
*/
public PointerBuffer put(long[] src, int offset, int length) {
if ( is64Bit )
view64.put(src, offset, length);
else {
checkBounds(offset, length, src.length);
if ( length > view32.remaining() )
throw new BufferOverflowException();
int end = offset + length;
for ( int i = offset; i < end; i++ )
view32.put((int)src[i]);
}
return this;
}
/**
* Relative bulk <i>put</i> method <i>(optional operation)</i>.
* <p/>
* <p> This method transfers the entire content of the given source
* long array into this buffer. An invocation of this method of the
* form <tt>dst.put(a)</tt> behaves in exactly the same way as the
* invocation
* <p/>
* <pre>
* dst.put(a, 0, a.length) </pre>
*
* @return This buffer
*
* @throws BufferOverflowException If there is insufficient space in this buffer
* @throws ReadOnlyBufferException If this buffer is read-only
*/
public final PointerBuffer put(long[] src) {
return put(src, 0, src.length);
}
/**
* Compacts this buffer <i>(optional operation)</i>.
* <p/>
* <p> The longs between the buffer's current position and its limit,
* if any, are copied to the beginning of the buffer. That is, the
* long at index <i>p</i> = <tt>position()</tt> is copied
* to index zero, the long at index <i>p</i> + 1 is copied
* to index one, and so forth until the long at index
* <tt>limit()</tt> - 1 is copied to index
* <i>n</i> = <tt>limit()</tt> - <tt>1</tt> - <i>p</i>.
* The buffer's position is then set to <i>n+1</i> and its limit is set to
* its capacity. The mark, if defined, is discarded.
* <p/>
* <p> The buffer's position is set to the number of longs copied,
* rather than to zero, so that an invocation of this method can be
* followed immediately by an invocation of another relative <i>put</i>
* method. </p>
*
* @return This buffer
*
* @throws ReadOnlyBufferException If this buffer is read-only
*/
public PointerBuffer compact() {
if ( is64Bit )
view64.compact();
else
view32.compact();
return this;
}
/**
* Retrieves this buffer's byte order.
* <p/>
* <p> The byte order of a pointer buffer created by allocation or by
* wrapping an existing <tt>long</tt> array is the {@link
* ByteOrder#nativeOrder </code>native order<code>} of the underlying
* hardware. The byte order of a pointer buffer created as a <a
* href="ByteBuffer.html#views">view</a> of a byte buffer is that of the
* byte buffer at the moment that the view is created. </p>
*
* @return This buffer's byte order
*/
public ByteOrder order() {
if ( is64Bit )
return view64.order();
else
return view32.order();
}
/**
* Returns a string summarizing the state of this buffer. </p>
*
* @return A summary string
*/
public String toString() {
StringBuilder sb = new StringBuilder(48);
sb.append(getClass().getName());
sb.append("[pos=");
sb.append(position());
sb.append(" lim=");
sb.append(limit());
sb.append(" cap=");
sb.append(capacity());
sb.append("]");
return sb.toString();
}
/**
* Returns the current hash code of this buffer.
* <p/>
* <p> The hash code of a pointer buffer depends only upon its remaining
* elements; that is, upon the elements from <tt>position()</tt> up to, and
* including, the element at <tt>limit()</tt> - <tt>1</tt>.
* <p/>
* <p> Because buffer hash codes are content-dependent, it is inadvisable
* to use buffers as keys in hash maps or similar data structures unless it
* is known that their contents will not change. </p>
*
* @return The current hash code of this buffer
*/
public int hashCode() {
int h = 1;
int p = position();
for ( int i = limit() - 1; i >= p; i-- )
h = 31 * h + (int)get(i);
return h;
}
/**
* Tells whether or not this buffer is equal to another object.
* <p/>
* <p> Two pointer buffers are equal if, and only if,
* <p/>
* <p><ol>
* <p/>
* <li><p> They have the same element type, </p></li>
* <p/>
* <li><p> They have the same number of remaining elements, and
* </p></li>
* <p/>
* <li><p> The two sequences of remaining elements, considered
* independently of their starting positions, are pointwise equal.
* </p></li>
* <p/>
* </ol>
* <p/>
* <p> A pointer buffer is not equal to any other type of object. </p>
*
* @param ob The object to which this buffer is to be compared
*
* @return <tt>true</tt> if, and only if, this buffer is equal to the
* given object
*/
public boolean equals(Object ob) {
if ( !(ob instanceof PointerBuffer) )
return false;
PointerBuffer that = (PointerBuffer)ob;
if ( this.remaining() != that.remaining() )
return false;
int p = this.position();
for ( int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j-- ) {
long v1 = this.get(i);
long v2 = that.get(j);
if ( v1 != v2 ) {
return false;
}
}
return true;
}
/**
* Compares this buffer to another.
* <p/>
* <p> Two pointer buffers are compared by comparing their sequences of
* remaining elements lexicographically, without regard to the starting
* position of each sequence within its corresponding buffer.
* <p/>
* <p> A pointer buffer is not comparable to any other type of object.
*
* @return A negative integer, zero, or a positive integer as this buffer
* is less than, equal to, or greater than the given buffer
*/
public int compareTo(Object o) {
final PointerBuffer that = (PointerBuffer)o;
int n = this.position() + Math.min(this.remaining(), that.remaining());
for ( int i = this.position(), j = that.position(); i < n; i++, j++ ) {
long v1 = this.get(i);
long v2 = that.get(j);
if ( v1 == v2 )
continue;
if ( v1 < v2 )
return -1;
return +1;
}
return this.remaining() - that.remaining();
}
private static void checkBounds(int off, int len, int size) {
if ( (off | len | (off + len) | (size - (off + len))) < 0 )
throw new IndexOutOfBoundsException();
}
/**
* Read-only version of PointerBuffer.
*
* @author Spasi
*/
private static final class PointerBufferR extends PointerBuffer {
PointerBufferR(final ByteBuffer source) {
super(source);
}
public boolean isReadOnly() {
return true;
}
protected PointerBuffer newInstance(final ByteBuffer source) {
return new PointerBufferR(source);
}
public PointerBuffer asReadOnlyBuffer() {
return duplicate();
}
public PointerBuffer put(final long l) {
throw new ReadOnlyBufferException();
}
public PointerBuffer put(final int index, final long l) {
throw new ReadOnlyBufferException();
}
public PointerBuffer put(final PointerBuffer src) {
throw new ReadOnlyBufferException();
}
public PointerBuffer put(final long[] src, final int offset, final int length) {
throw new ReadOnlyBufferException();
}
public PointerBuffer compact() {
throw new ReadOnlyBufferException();
}
}
}