@Override
public void link(
final FileMetadata metadata,
final long newParentId,
final String newFileName,
final AtomicDBUpdate update) {
// get the link source
BufferBackedFileMetadata md = (BufferBackedFileMetadata) metadata;
// increment the link count
short links = metadata.getLinkCount();
md.setLinkCount((short) (links + 1));
// insert the whole metadata of the original file in the file ID
// index
update.addUpdate(
FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(metadata.getId(), FileMetadata.FC_METADATA),
md.getFCMetadataValue());
update.addUpdate(
FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(metadata.getId(), FileMetadata.RC_METADATA),
md.getRCMetadata().getValue());
// remove the back link
update.addUpdate(
FILE_ID_INDEX, BabuDBStorageHelper.createFileIdIndexKey(metadata.getId(), (byte) 3), null);
// if the metadata was retrieved from the FILE_INDEX and hasn't
// been deleted before (i.e. links == 0), ensure that the original
// file in the file index now points to the file ID index, and
// remove the FC and XLoc metadata entries
if (links != 0 && md.getIndexId() == FILE_INDEX) {
update.addUpdate(
FILE_INDEX,
md.getRCMetadata().getKey(),
BabuDBStorageHelper.createLinkTarget(metadata.getId()));
update.addUpdate(FILE_INDEX, md.getFCMetadataKey(), null);
}
// create an entry for the new link to the metadata in the file
// index
update.addUpdate(
FILE_INDEX,
BabuDBStorageHelper.createFileKey(newParentId, newFileName, FileMetadata.RC_METADATA),
BabuDBStorageHelper.createLinkTarget(metadata.getId()));
}
@Override
public short unlink(final long parentId, final String fileName, final AtomicDBUpdate update)
throws DatabaseException {
try {
// retrieve the file metadata
BufferBackedFileMetadata file = BabuDBStorageHelper.getMetadata(database, parentId, fileName);
// determine and set the new link count
short newLinkCount = (short) (file.getLinkCount() - 1);
file.setLinkCount(newLinkCount);
// if there will be links remaining after the deletion, update the
// link count; it must be in the FILE_ID_INDEX, because there have
// been at least two links
if (newLinkCount > 0)
update.addUpdate(
FILE_ID_INDEX,
BabuDBStorageHelper.createFileIdIndexKey(file.getId(), FileMetadata.RC_METADATA),
file.getRCMetadata().getValue());
// remove all entries from the file index
update.addUpdate(
FILE_INDEX,
BabuDBStorageHelper.createFileKey(parentId, fileName, FileMetadata.FC_METADATA),
null);
update.addUpdate(
FILE_INDEX,
BabuDBStorageHelper.createFileKey(parentId, fileName, FileMetadata.RC_METADATA),
null);
return newLinkCount;
} catch (BabuDBException exc) {
throw new DatabaseException(exc);
}
}
@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);
}
}