/**
* Reads a block from disk.
*
* @param b block to fetch
*/
private void readBlock(final int b) {
if (!bm.cursor(b)) return;
final Buffer bf = bm.current();
try {
if (bf.dirty) writeBlock(bf);
bf.pos = b;
if (b >= blocks) {
blocks = b + 1;
} else {
file.seek(bf.pos * IO.BLOCKSIZE);
file.readFully(bf.data);
}
} catch (final IOException ex) {
Util.stack(ex);
}
}
/**
* Writes the specified block to disk and resets the dirty flag.
*
* @param bf buffer to write
* @throws IOException I/O exception
*/
private void writeBlock(final Buffer bf) throws IOException {
file.seek(bf.pos * IO.BLOCKSIZE);
file.write(bf.data);
bf.dirty = false;
}