/**
* Remove the snapshot with the given name from {@link #snapshotsByNames}, and delete all the
* corresponding DirectoryDiff.
*
* @param snapshotName The name of the snapshot to be removed
* @param collectedBlocks Used to collect information to update blocksMap
* @return The removed snapshot. Null if no snapshot with the given name exists.
*/
Snapshot removeSnapshot(
String snapshotName, BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes)
throws SnapshotException {
final int i = searchSnapshot(DFSUtil.string2Bytes(snapshotName));
if (i < 0) {
throw new SnapshotException(
"Cannot delete snapshot "
+ snapshotName
+ " from path "
+ this.getFullPathName()
+ ": the snapshot does not exist.");
} else {
final Snapshot snapshot = snapshotsByNames.get(i);
Snapshot prior = Snapshot.findLatestSnapshot(this, snapshot);
try {
Quota.Counts counts = cleanSubtree(snapshot, prior, collectedBlocks, removedINodes, true);
INodeDirectory parent = getParent();
if (parent != null) {
// there will not be any WithName node corresponding to the deleted
// snapshot, thus only update the quota usage in the current tree
parent.addSpaceConsumed(-counts.get(Quota.NAMESPACE), -counts.get(Quota.DISKSPACE), true);
}
} catch (QuotaExceededException e) {
LOG.error("BUG: removeSnapshot increases namespace usage.", e);
}
// remove from snapshotsByNames after successfully cleaning the subtree
snapshotsByNames.remove(i);
return snapshot;
}
}
