|
Known Indirect Subclasses
AbstractDataBufferWindow<B extends DataBuffer<?>>
|
A mutable container for viewing part of a DataBuffer.
Data buffer windows have a fixed size and can "slide"
along a buffer to provide different views of the data without allocating a new buffer instance,
like offset(long) does. This improves overall performance when this operation
is repeated frequently. For example:
IntDataBuffer bufferA = DataBuffers.ofInts(1024);
// ... init buffer data
IntDataBuffer bufferB = DataBuffers.ofInts(1, 2, 3, 4);
// Return the index of the first occurrence of bufferB in bufferA using a sliding window
DataBufferWindow<IntDataBuffer> windowA = bufferA.window(4);
for (int i = 0; i < bufferA.size() - bufferB.size(); ++i) {
if (windowA.slideTo(i).buffer().equals(bufferB)) {
return i;
}
}DataBufferWindow instances are stateful and not thread-safe.
Public Methods
| abstract B |
buffer()
Returns the buffer backing this window.
|
| abstract long |
offset()
Returns the current offset of this window in the original buffer.
|
| abstract long |
size()
Returns the size of this buffer window.
|
| abstract DataBufferWindow<B> |
slide(long step)
Moves the window of
step elements in the original buffer. |
| abstract DataBufferWindow<B> |
slideTo(long index)
Moves the window at the given position in the original buffer.
|
Public Methods
public abstract B buffer ()
Returns the buffer backing this window.
Each window instance has it's own buffer providing a view onto the original
DataBuffer. The buffers are mutated when the window slides to different offsets.
For example:
IntDataBuffer buffer = DataBuffers.of(0, 1, 2, 3);
DataBufferWindow<IntDataBuffer> window = buffer.window(0, 2);
IntDataBuffer windowBuffer = window.buffer();
assertEquals(0, windowBuffer.getInt(0));
assertEquals(1, windowBuffer.getInt(1));
window.slideTo(2);
assertEquals(2, windowBuffer.getInt(0));
assertEquals(3, windowBuffer.getInt(1));
assertSame(windowBuffer, window.buffer());
Returns
- this window's buffer
public abstract long offset ()
Returns the current offset of this window in the original buffer.
public abstract long size ()
Returns the size of this buffer window.
public abstract DataBufferWindow<B> slide (long step)
Moves the window of step elements in the original buffer.
The size of the window remains the same and its offset is set to offset() + step.
If step is positive, then the window will slide forward. If it is negative, it will
slide backward.
Parameters
| step | value to add to the current offset of this window |
|---|
Returns
- this instance
Throws
| IndexOutOfBoundsException | if the window cannot be slid because it goes beyond the original buffer limits |
|---|
public abstract DataBufferWindow<B> slideTo (long index)
Moves the window at the given position in the original buffer.
The size of the window remains the same and its offset is set to index, so that
accessing the value of buffer() at index x will return the value at
index + x in the original buffer.
Parameters
| index | new offset for this window |
|---|
Returns
- this instance
Throws
| IndexOutOfBoundsException | if the window cannot be slid because it goes beyond the original buffer limits |
|---|