/**
* Write the filesystem out
*
* @param stream the OutputStream to which the filesystem will be written
* @exception IOException thrown on errors writing to the stream
*/
public void writeFilesystem(final OutputStream stream) throws IOException {
// Have the datasource updated
syncWithDataSource();
// Now copy the contents to the stream
_data.copyTo(stream);
}
private BATBlock createBAT(int offset, boolean isBAT) throws IOException {
// Create a new BATBlock
BATBlock newBAT = BATBlock.createEmptyBATBlock(bigBlockSize, !isBAT);
newBAT.setOurBlockIndex(offset);
// Ensure there's a spot in the file for it
ByteBuffer buffer = ByteBuffer.allocate(bigBlockSize.getBigBlockSize());
int writeTo = (1 + offset) * bigBlockSize.getBigBlockSize(); // Header isn't in BATs
_data.write(buffer, writeTo);
// All done
return newBAT;
}
/** Load the block at the given offset, extending the file if needed */
@Override
protected ByteBuffer createBlockIfNeeded(final int offset) throws IOException {
try {
return getBlockAt(offset);
} catch (IndexOutOfBoundsException e) {
// The header block doesn't count, so add one
long startAt = (offset + 1) * bigBlockSize.getBigBlockSize();
// Allocate and write
ByteBuffer buffer = ByteBuffer.allocate(getBigBlockSize());
_data.write(buffer, startAt);
// Retrieve the properly backed block
return getBlockAt(offset);
}
}
/**
* Closes the FileSystem, freeing any underlying files, streams and buffers. After this, you will
* be unable to read or write from the FileSystem.
*/
public void close() throws IOException {
_data.close();
}
@Override
protected ChainLoopDetector getChainLoopDetector() throws IOException {
return new ChainLoopDetector(_data.size());
}
/** Load the block at the given offset. */
@Override
protected ByteBuffer getBlockAt(final int offset) throws IOException {
// The header block doesn't count, so add one
long startAt = (offset + 1) * bigBlockSize.getBigBlockSize();
return _data.read(bigBlockSize.getBigBlockSize(), startAt);
}
