/// <summary>
/// <inheritDoc/>
/// <br/>
/// To destroy a DstReference node, we first remove its link with the
/// referred node. If the reference number of the referred node is <= 0, we
/// destroy the subtree of the referred node. Otherwise, we clean the
/// referred node's subtree and delete everything created after the last
/// rename operation, i.e., everything outside of the scope of the prior
/// WithName nodes.
/// </summary>
public override void DestroyAndCollectBlocks(BlockStoragePolicySuite bsps, INode.BlocksMapUpdateInfo
collectedBlocks, IList <INode> removedINodes)
{
if (RemoveReference(this) <= 0)
{
GetReferredINode().DestroyAndCollectBlocks(bsps, collectedBlocks, removedINodes);
}
else
{
// we will clean everything, including files, directories, and
// snapshots, that were created after this prior snapshot
int prior = GetPriorSnapshot(this);
// prior must be non-null, otherwise we do not have any previous
// WithName nodes, and the reference number will be 0.
Preconditions.CheckState(prior != Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot
.NoSnapshotId);
// identify the snapshot created after prior
int snapshot = GetSelfSnapshot(prior);
INode referred = GetReferredINode().AsReference().GetReferredINode();
if (referred.IsFile())
{
// if referred is a file, it must be a file with snapshot since we did
// recordModification before the rename
INodeFile file = referred.AsFile();
Preconditions.CheckState(file.IsWithSnapshot());
// make sure we mark the file as deleted
file.GetFileWithSnapshotFeature().DeleteCurrentFile();
// when calling cleanSubtree of the referred node, since we
// compute quota usage updates before calling this destroy
// function, we use true for countDiffChange
referred.CleanSubtree(bsps, snapshot, prior, collectedBlocks, removedINodes);
}
else
{
if (referred.IsDirectory())
{
// similarly, if referred is a directory, it must be an
// INodeDirectory with snapshot
INodeDirectory dir = referred.AsDirectory();
Preconditions.CheckState(dir.IsWithSnapshot());
try
{
DirectoryWithSnapshotFeature.DestroyDstSubtree(bsps, dir, snapshot, prior, collectedBlocks
, removedINodes);
}
catch (QuotaExceededException e)
{
Log.Error("should not exceed quota while snapshot deletion", e);
}
}
}
}
}
