public Extent(HfsPlusFileSystem fs) throws IOException {
log.debug("Load B-Tree extent overflow file.");
this.fs = fs;
SuperBlock sb = fs.getVolumeHeader();
extentFile = sb.getExtentsFile();
if (!extentFile.getExtent(0).isEmpty()) {
buffer =
ByteBuffer.allocate(
NodeDescriptor.BT_NODE_DESCRIPTOR_LENGTH + BTHeaderRecord.BT_HEADER_RECORD_LENGTH);
extentFile.read(fs, 0, buffer);
buffer.rewind();
byte[] data = ByteBufferUtils.toArray(buffer);
log.debug("Load extent node descriptor.");
btnd = new NodeDescriptor(data, 0);
log.debug(btnd.toString());
log.debug("Load extent header record.");
bthr = new BTHeaderRecord(data, NodeDescriptor.BT_NODE_DESCRIPTOR_LENGTH);
log.debug(bthr.toString());
}
}
/**
* Gets all overflow extents that match the given key.
*
* @param key the key to match.
* @param nodeNumber the current node to read from.
* @return the overflow extents.
* @throws IOException if an error occurs.
*/
public final ExtentDescriptor[] getOverflowExtents(final ExtentKey key, long nodeNumber)
throws IOException {
try {
long currentNodeNumber = nodeNumber;
int nodeSize = bthr.getNodeSize();
ByteBuffer nodeData = ByteBuffer.allocate(nodeSize);
extentFile.read(fs, (currentNodeNumber * nodeSize), nodeData);
byte[] data = nodeData.array();
NodeDescriptor nd = new NodeDescriptor(data, 0);
if (nd.isIndexNode()) {
ExtentNode extentNode = new ExtentNode(data, nodeSize);
IndexRecord[] records = extentNode.findAll(key);
List<ExtentDescriptor> overflowExtents = new LinkedList<ExtentDescriptor>();
for (IndexRecord record : records) {
Collections.addAll(overflowExtents, getOverflowExtents(key, record.getIndex()));
}
return overflowExtents.toArray(new ExtentDescriptor[overflowExtents.size()]);
} else if (nd.isLeafNode()) {
ExtentLeafNode node = new ExtentLeafNode(nodeData.array(), nodeSize);
return node.getOverflowExtents(key);
} else {
log.info(
String.format(
"Node %d wasn't a leaf or index: %s\n%s", nodeNumber, nd, NumberUtils.hex(data)));
return new ExtentDescriptor[0];
}
} catch (Exception e) {
e.printStackTrace();
throw new IOException(e);
}
}
/**
* Gets all overflow extents that match the given key.
*
* @param key the key to match.
* @return the overflow extents.
* @throws IOException if an error occurs.
*/
public final ExtentDescriptor[] getOverflowExtents(final ExtentKey key) throws IOException {
return getOverflowExtents(key, bthr.getRootNode());
}