// single pass attempt to copy if any can not accept the data then they are skipped
// and true will be returned instead of false.
private static boolean doingCopy(
TapeWriteStage ss,
int byteTailPos,
int primaryTailPos,
int totalPrimaryCopy,
int totalBytesCopy) {
IntBuffer primaryInts = RingBuffer.wrappedStructuredLayoutRingBuffer(ss.source);
ByteBuffer secondaryBytes = RingBuffer.wrappedUnstructuredLayoutRingBufferA(ss.source);
primaryInts.position(primaryTailPos);
primaryInts.limit(
primaryTailPos
+ totalPrimaryCopy); // TODO: AA, this will not work on the wrap, we must mask and do
// muliple copies
secondaryBytes.position(byteTailPos);
secondaryBytes.limit(byteTailPos + totalBytesCopy);
ss.header.clear();
ss.headerAsInts.put(totalBytesCopy + (totalPrimaryCopy << 2));
ss.headerAsInts.put(totalPrimaryCopy << 2);
// TODO: must return false if there is no room to write.
// TODO: BB, this creates a bit of garbage for the map, perhaps we should map larger blocks
// expecting to use them for multiple writes.
MappedByteBuffer mapped;
try {
mapped =
ss.fileChannel.map(
MapMode.READ_WRITE,
ss.fileChannel.position(),
8 + totalBytesCopy + (totalPrimaryCopy << 2));
mapped.put(ss.header);
IntBuffer asIntBuffer = mapped.asIntBuffer();
asIntBuffer.position(2);
asIntBuffer.put(primaryInts);
mapped.position(mapped.position() + (totalPrimaryCopy << 2));
mapped.put(secondaryBytes);
} catch (IOException e) {
throw new RuntimeException(e);
}
return true;
}
