@Override
public byte[] getXAttr(long fileId, String uid, String key) throws DatabaseException {
ResultSet<byte[], byte[]> it = null;
try {
// peform a prefix lookup
byte[] prefix = BabuDBStorageHelper.createXAttrPrefixKey(fileId, uid, key);
it = database.prefixLookup(XATTRS_INDEX, prefix, null).get();
// check whether the entry is the correct one
while (it.hasNext()) {
Entry<byte[], byte[]> curr = it.next();
BufferBackedXAttr xattr = new BufferBackedXAttr(curr.getKey(), curr.getValue());
if (uid.equals(xattr.getOwner()) && key.equals(xattr.getKey())) return xattr.getValue();
}
return null;
} catch (BabuDBException exc) {
throw new DatabaseException(exc);
} finally {
if (it != null) it.free();
}
}
@Override
public FileMetadata getMetadata(long fileId) throws DatabaseException {
try {
// create the key for the file ID index lookup
byte[] key = BabuDBStorageHelper.createFileIdIndexKey(fileId, (byte) -1);
ByteBuffer.wrap(key).putLong(fileId);
byte[][] valBufs = new byte[BufferBackedFileMetadata.NUM_BUFFERS][];
// retrieve the metadata from the link index
ResultSet<byte[], byte[]> it =
database.prefixLookup(BabuDBStorageManager.FILE_ID_INDEX, key, null).get();
while (it.hasNext()) {
Entry<byte[], byte[]> curr = it.next();
int type = BabuDBStorageHelper.getType(curr.getKey(), BabuDBStorageManager.FILE_ID_INDEX);
// if the value is a back link, resolve it
if (type == 3) {
long parentId = ByteBuffer.wrap(curr.getValue()).getLong();
String fileName = new String(curr.getValue(), 8, curr.getValue().length - 8);
return getMetadata(parentId, fileName);
}
valBufs[type] = curr.getValue();
}
it.free();
// if not metadata was found for the file ID, return null
if (valBufs[FileMetadata.RC_METADATA] == null) return null;
byte[][] keyBufs =
new byte[][] {null, BabuDBStorageHelper.createFileKey(0, "", FileMetadata.RC_METADATA)};
// otherwise, a hard link target is contained in the index; create a
// new metadata object in this case
return new BufferBackedFileMetadata(keyBufs, valBufs, BabuDBStorageManager.FILE_ID_INDEX);
} catch (BabuDBException exc) {
throw new DatabaseException(exc);
}
}
public void dump() throws BabuDBException {
System.out.println("FILE_ID_INDEX");
ResultSet<byte[], byte[]> it = database.prefixLookup(FILE_ID_INDEX, new byte[0], null).get();
while (it.hasNext()) {
Entry<byte[], byte[]> next = it.next();
System.out.println(Arrays.toString(next.getKey()) + " = " + Arrays.toString(next.getValue()));
}
it.free();
System.out.println("\nFILE_INDEX");
it = database.prefixLookup(FILE_INDEX, new byte[0], null).get();
while (it.hasNext()) {
Entry<byte[], byte[]> next = it.next();
System.out.println(Arrays.toString(next.getKey()) + " = " + Arrays.toString(next.getValue()));
}
it.free();
}
@Override
public short delete(final long parentId, final String fileName, final AtomicDBUpdate update)
throws DatabaseException {
try {
// retrieve the file metadata
BufferBackedFileMetadata file = BabuDBStorageHelper.getMetadata(database, parentId, fileName);
// check whether there is only one link remaining
short newLinkCount = (short) (file.getLinkCount() - 1);
assert (newLinkCount >= 0);
// decrement the link count
file.setLinkCount(newLinkCount);
// if there will be links remaining after the deletion, update the
// link count
if (newLinkCount > 0)
update.addUpdate(
FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(file.getId(), FileMetadata.RC_METADATA),
file.getRCMetadata().getValue());
// delete all keys ...
// remove all content from the file index
update.addUpdate(
BabuDBStorageManager.FILE_INDEX,
BabuDBStorageHelper.createFileKey(parentId, fileName, FileMetadata.FC_METADATA),
null);
update.addUpdate(
BabuDBStorageManager.FILE_INDEX,
BabuDBStorageHelper.createFileKey(parentId, fileName, FileMetadata.RC_METADATA),
null);
// if the last link to the file is supposed to be deleted, remove
// the remaining metadata, including ACLs and XAttrs
if (newLinkCount == 0) {
// remove the back link from the file ID index
update.addUpdate(
BabuDBStorageManager.FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(file.getId(), (byte) 3),
null);
// remove potentially existing metadata from the file ID index
update.addUpdate(
BabuDBStorageManager.FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(file.getId(), FileMetadata.FC_METADATA),
null);
update.addUpdate(
BabuDBStorageManager.FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(file.getId(), FileMetadata.RC_METADATA),
null);
byte[] idBytes = new byte[8];
ByteBuffer.wrap(idBytes).putLong(file.getId());
// remove all ACLs
ResultSet<byte[], byte[]> it =
database.prefixLookup(BabuDBStorageManager.ACL_INDEX, idBytes, null).get();
while (it.hasNext())
update.addUpdate(BabuDBStorageManager.ACL_INDEX, it.next().getKey(), null);
it.free();
// remove all extended attributes
it = database.prefixLookup(BabuDBStorageManager.XATTRS_INDEX, idBytes, null).get();
while (it.hasNext())
update.addUpdate(BabuDBStorageManager.XATTRS_INDEX, it.next().getKey(), null);
it.free();
// if a file is deleted, update file count and volume size
if (file.isDirectory()) {
updateCount(NUM_DIRS_KEY, false, update);
} else if (file.getXLocList() != null) {
volume.updateVolumeSize(-file.getSize(), update);
updateCount(NUM_FILES_KEY, false, update);
}
}
return file.getLinkCount();
} catch (BabuDBException exc) {
throw new DatabaseException(exc);
}
}