org.apache.hadoop.hdfs.server.namenode

Class INodeReference.DstReference

java.lang.Object

org.apache.hadoop.hdfs.server.namenode.INode

org.apache.hadoop.hdfs.server.namenode.INodeReference

org.apache.hadoop.hdfs.server.namenode.INodeReference.DstReference

All Implemented Interfaces:

Comparable<byte[]>, org.apache.hadoop.hdfs.server.namenode.INodeAttributes, Diff.Element<byte[]>

Enclosing class:

INodeReference

public static class INodeReference.DstReference
extends INodeReference

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hdfs.server.namenode.INodeReference

INodeReference.DstReference, INodeReference.WithCount, INodeReference.WithName

Nested classes/interfaces inherited from class org.apache.hadoop.hdfs.server.namenode.INode

INode.BlocksMapUpdateInfo, INode.Feature

Nested classes/interfaces inherited from interface org.apache.hadoop.hdfs.server.namenode.INodeAttributes

INodeAttributes.SnapshotCopy

Field Summary

Fields inherited from class org.apache.hadoop.hdfs.server.namenode.INode

LOG

Constructor Summary

Constructors

Constructor and Description
DstReference(INodeDirectory parent, INodeReference.WithCount referred, int dstSnapshotId)

Method Summary

Modifier and Type	Method and Description
QuotaCounts	cleanSubtree(BlockStoragePolicySuite bsps, int snapshot, int prior, INode.BlocksMapUpdateInfo collectedBlocks, List<org.apache.hadoop.hdfs.server.namenode.INode> removedINodes) Clean the subtree under this inode and collect the blocks from the descents for further block deletion/update.
void	destroyAndCollectBlocks(BlockStoragePolicySuite bsps, INode.BlocksMapUpdateInfo collectedBlocks, List<org.apache.hadoop.hdfs.server.namenode.INode> removedINodes) Destroy self and clear everything! If the INode is a file, this method collects its blocks for further block deletion.
int	getDstSnapshotId()

Methods inherited from class org.apache.hadoop.hdfs.server.namenode.INodeReference

asDirectory, asFile, asReference, asSymlink, clear, computeContentSummary, computeQuotaUsage, dumpTreeRecursively, getAccessTime, getFsPermission, getFsPermissionShort, getGroupName, getId, getLocalNameBytes, getLocalStoragePolicyID, getModificationTime, getPermissionLong, getPermissionStatus, getQuotaCounts, getReferredINode, getSnapshotINode, getStoragePolicyID, getUserName, isDirectory, isFile, isReference, isSymlink, setAccessTime, setLocalName, setModificationTime, setReferredINode, tryRemoveReference, updateModificationTime

Methods inherited from class org.apache.hadoop.hdfs.server.namenode.INode

addSpaceConsumed, compareTo, computeAndConvertContentSummary, computeContentSummary, computeQuotaUsage, computeQuotaUsage, dumpTreeRecursively, dumpTreeRecursively, equals, getAccessTime, getAclFeature, getFsPermission, getFullPathName, getGroupName, getKey, getLocalName, getModificationTime, getObjectString, getParent, getParentReference, getParentString, getPathComponents, getPathNames, getStoragePolicyIDForQuota, getUserName, getXAttrFeature, hashCode, isAncestorDirectory, isInLatestSnapshot, isQuotaSet, setAccessTime, setModificationTime, setParent, setParentReference, shouldRecordInSrcSnapshot, toDetailString, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DstReference

public DstReference(INodeDirectory parent,
                    INodeReference.WithCount referred,
                    int dstSnapshotId)

Method Detail

getDstSnapshotId

public final int getDstSnapshotId()

Overrides:

getDstSnapshotId in class INodeReference

cleanSubtree

public QuotaCounts cleanSubtree(BlockStoragePolicySuite bsps,
                                int snapshot,
                                int prior,
                                INode.BlocksMapUpdateInfo collectedBlocks,
                                List<org.apache.hadoop.hdfs.server.namenode.INode> removedINodes)

Description copied from class: org.apache.hadoop.hdfs.server.namenode.INode

Clean the subtree under this inode and collect the blocks from the descents for further block deletion/update. The current inode can either resides in the current tree or be stored as a snapshot copy.

 In general, we have the following rules. 
 1. When deleting a file/directory in the current tree, we have different 
 actions according to the type of the node to delete. 
 
 1.1 The current inode (this) is an INodeFile. 
 1.1.1 If  prior is null, there is no snapshot taken on ancestors 
 before. Thus we simply destroy (i.e., to delete completely, no need to save 
 snapshot copy) the current INode and collect its blocks for further 
 cleansing.
 1.1.2 Else do nothing since the current INode will be stored as a snapshot
 copy.
 
 1.2 The current inode is an INodeDirectory.
 1.2.1 If  prior is null, there is no snapshot taken on ancestors 
 before. Similarly, we destroy the whole subtree and collect blocks.
 1.2.2 Else do nothing with the current INode. Recursively clean its 
 children.
 
 1.3 The current inode is a file with snapshot.
 Call recordModification(..) to capture the current states.
 Mark the INode as deleted.
 
 1.4 The current inode is an INodeDirectory with snapshot feature.
 Call recordModification(..) to capture the current states. 
 Destroy files/directories created after the latest snapshot 
 (i.e., the inodes stored in the created list of the latest snapshot).
 Recursively clean remaining children. 

 2. When deleting a snapshot.
 2.1 To clean INodeFile: do nothing.
 2.2 To clean INodeDirectory: recursively clean its children.
 2.3 To clean INodeFile with snapshot: delete the corresponding snapshot in
 its diff list.
 2.4 To clean INodeDirectory with snapshot: delete the corresponding 
 snapshot in its diff list. Recursively clean its children.
 

Overrides:

cleanSubtree in class INodeReference

Parameters:

bsps - block storage policy suite to calculate intended storage type usage

snapshot - The id of the snapshot to delete. Snapshot.CURRENT_STATE_ID means to delete the current file/directory.

prior - The id of the latest snapshot before the to-be-deleted snapshot. When deleting a current inode, this parameter captures the latest snapshot.

collectedBlocks - blocks collected from the descents for further block deletion/update will be added to the given map.

removedINodes - INodes collected from the descents for further cleaning up of inodeMap

Returns:

quota usage delta when deleting a snapshot

destroyAndCollectBlocks

public void destroyAndCollectBlocks(BlockStoragePolicySuite bsps,
                                    INode.BlocksMapUpdateInfo collectedBlocks,
                                    List<org.apache.hadoop.hdfs.server.namenode.INode> removedINodes)

Destroy self and clear everything! If the INode is a file, this method collects its blocks for further block deletion. If the INode is a directory, the method goes down the subtree and collects blocks from the descents, and clears its parent/children references as well. The method also clears the diff list if the INode contains snapshot diff list.
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.

Overrides:

destroyAndCollectBlocks in class INodeReference

Parameters:

bsps - block storage policy suite to calculate intended storage type usage This is needed because INodeReference#destroyAndCollectBlocks() needs to call INode#cleanSubtree(), which calls INode#computeQuotaUsage().

collectedBlocks - blocks collected from the descents for further block deletion/update will be added to this map.

removedINodes - INodes collected from the descents for further cleaning up of inodeMap