/**
* Write this node to the given file channel.
*
* @param fc The file channel to write to (should be sought to be correct position)
* @throws IOException If there was an error writing
*/
public final void writeSelf(FileChannel fc) throws IOException {
/*
* Yes, we are taking the *read* lock here, because we are reading the
* information in the node to write it to disk.
*/
fRwl.readLock().lock();
try {
final int blockSize = fConfig.getBlockSize();
int curStringsEntryEndPos = blockSize;
ByteBuffer buffer = ByteBuffer.allocate(blockSize);
buffer.order(ByteOrder.LITTLE_ENDIAN);
buffer.clear();
/* Write the common header part */
buffer.put(getNodeType().toByte());
buffer.putLong(fNodeStart);
buffer.putLong(fNodeEnd);
buffer.putInt(fSequenceNumber);
buffer.putInt(fParentSequenceNumber);
buffer.putInt(fIntervals.size());
buffer.putInt(fStringSectionOffset);
buffer.put((byte) 1); // TODO Used to be "isDone", to be removed from header
/* Now call the inner method to write the specific header part */
writeSpecificHeader(buffer);
/* Back to us, we write the intervals */
for (HTInterval interval : fIntervals) {
int size = interval.writeInterval(buffer, curStringsEntryEndPos);
curStringsEntryEndPos -= size;
}
/*
* Write padding between the end of the Data section and the start
* of the Strings section (needed to fill the node in case there is
* no Strings section)
*/
while (buffer.position() < fStringSectionOffset) {
buffer.put((byte) 0);
}
/*
* If the offsets were right, the size of the Strings section should
* be == to the expected size
*/
assert (curStringsEntryEndPos == fStringSectionOffset);
/* Finally, write everything in the Buffer to disk */
// if we don't do this, flip() will lose what's after.
buffer.position(blockSize);
buffer.flip();
int res = fc.write(buffer);
assert (res == blockSize);
} finally {
fRwl.readLock().unlock();
}
fIsOnDisk = true;
}
