org.apache.hadoop.hdfs.server.namenode

Class INodeDirectory

java.lang.Object

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

org.apache.hadoop.hdfs.server.namenode.INodeWithAdditionalFields

org.apache.hadoop.hdfs.server.namenode.INodeDirectory

All Implemented Interfaces:

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

Direct Known Subclasses:

Snapshot.Root

public class INodeDirectory
extends org.apache.hadoop.hdfs.server.namenode.INodeWithAdditionalFields
implements org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes

Directory INode class.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	INodeDirectory.SnapshotAndINode A pair of Snapshot and INode objects.

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

INode.BlocksMapUpdateInfo, INode.Feature, INode.QuotaDelta, INode.ReclaimContext

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

INodeDirectoryAttributes.CopyWithQuota, INodeDirectoryAttributes.SnapshotCopy

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_FILES_PER_DIRECTORY

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

features

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

LOG

Constructor Summary

Constructors

Constructor and Description
INodeDirectory(INodeDirectory other, boolean adopt, INode.Feature... featuresToCopy) Copy constructor
INodeDirectory(long id, byte[] name, org.apache.hadoop.fs.permission.PermissionStatus permissions, long mtime) constructor

Method Summary

Methods

Modifier and Type	Method and Description
boolean	addChild(org.apache.hadoop.hdfs.server.namenode.INode node)
boolean	addChild(org.apache.hadoop.hdfs.server.namenode.INode node, boolean setModTime, int latestSnapshotId) Add a child inode to the directory.
org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot	addSnapshot(int id, String name)
org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature	addSnapshotFeature(DirectoryWithSnapshotFeature.DirectoryDiffList diffs)
void	addSnapshottableFeature() add DirectorySnapshottableFeature
void	addSpaceConsumed(QuotaCounts counts, boolean verify) Check and add namespace/storagespace/storagetype consumed to itself and the ancestors.
INodeDirectory	asDirectory() Cast this inode to an INodeDirectory.
void	cleanSubtree(INode.ReclaimContext reclaimContext, int snapshotId, int priorSnapshotId) Clean the subtree under this inode and collect the blocks from the descents for further block deletion/update.
void	cleanSubtreeRecursively(INode.ReclaimContext reclaimContext, int snapshot, int prior, Map<org.apache.hadoop.hdfs.server.namenode.INode,org.apache.hadoop.hdfs.server.namenode.INode> excludedNodes) Call cleanSubtree(..) recursively down the subtree.
void	clear() Clear references to other objects.
void	clearChildren() Set the children list to null.
org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext	computeContentSummary(int snapshotId, org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext summary) Count subtree content summary with a ContentCounts.
protected org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext	computeDirectoryContentSummary(org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext summary, int snapshotId)
QuotaCounts	computeQuotaUsage(BlockStoragePolicySuite bsps, byte blockStoragePolicyId, boolean useCache, int lastSnapshotId) Count subtree Quota.NAMESPACE and Quota.STORAGESPACE usages.
QuotaCounts	computeQuotaUsage4CurrentDirectory(BlockStoragePolicySuite bsps, byte storagePolicyId, QuotaCounts counts) Add quota usage for this inode excluding children.
void	destroyAndCollectBlocks(INode.ReclaimContext reclaimContext) Destroy self and clear everything! If the INode is a file, this method collects its blocks for further block deletion.
void	dumpTreeRecursively(PrintWriter out, StringBuilder prefix, int snapshot) Dump tree recursively.
static void	dumpTreeRecursively(PrintWriter out, StringBuilder prefix, Iterable<INodeDirectory.SnapshotAndINode> subs) Dump the given subtrees.
org.apache.hadoop.hdfs.server.namenode.INode	getChild(byte[] name, int snapshotId)
org.apache.hadoop.hdfs.util.ReadOnlyList<org.apache.hadoop.hdfs.server.namenode.INode>	getChildrenList(int snapshotId)
int	getChildrenNum(int snapshotId)
DirectoryWithSnapshotFeature.DirectoryDiffList	getDiffs()
org.apache.hadoop.hdfs.server.namenode.snapshot.DirectorySnapshottableFeature	getDirectorySnapshottableFeature()
DirectoryWithQuotaFeature	getDirectoryWithQuotaFeature() If the directory contains a DirectoryWithQuotaFeature, return it; otherwise, return null.
org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature	getDirectoryWithSnapshotFeature() If feature list contains a DirectoryWithSnapshotFeature, return it; otherwise, return null.
byte	getLocalStoragePolicyID()
QuotaCounts	getQuotaCounts() Get the quota set for this inode
org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot	getSnapshot(byte[] snapshotName)
org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes	getSnapshotINode(int snapshotId)
byte	getStoragePolicyID()
boolean	isDirectory() Check whether it's a directory
boolean	isSnapshottable()
boolean	isWithSnapshot() Is this file has the snapshot feature?
boolean	metadataEquals(org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes other) Compare the metadata with another INodeDirectory
void	recordModification(int latestSnapshotId) This inode is being modified.
boolean	removeChild(org.apache.hadoop.hdfs.server.namenode.INode child) Remove the specified child from this directory.
boolean	removeChild(org.apache.hadoop.hdfs.server.namenode.INode child, int latestSnapshotId) Remove the specified child from this directory.
org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot	removeSnapshot(INode.ReclaimContext reclaimContext, String snapshotName)
void	removeSnapshottableFeature() remove DirectorySnapshottableFeature
void	renameSnapshot(String path, String oldName, String newName)
void	replaceChild(org.apache.hadoop.hdfs.server.namenode.INode oldChild, org.apache.hadoop.hdfs.server.namenode.INode newChild, INodeMap inodeMap) Replace the given child with a new child.
org.apache.hadoop.hdfs.server.namenode.INode	saveChild2Snapshot(org.apache.hadoop.hdfs.server.namenode.INode child, int latestSnapshotId, org.apache.hadoop.hdfs.server.namenode.INode snapshotCopy) Save the child to the latest snapshot.
int	searchChild(org.apache.hadoop.hdfs.server.namenode.INode inode) Search for the given INode in the children list and the deleted lists of snapshots.
void	setSnapshotQuota(int snapshotQuota)
String	toDetailString()
void	undoRename4DstParent(BlockStoragePolicySuite bsps, org.apache.hadoop.hdfs.server.namenode.INode deletedChild, int latestSnapshotId) Undo the rename operation for the dst tree, i.e., if the rename operation (with OVERWRITE option) removes a file/dir from the dst tree, add it back and delete possible record in the deleted list.
void	undoRename4ScrParent(INodeReference oldChild, org.apache.hadoop.hdfs.server.namenode.INode newChild) This method is usually called by the undo section of rename.
static INodeDirectory	valueOf(org.apache.hadoop.hdfs.server.namenode.INode inode, Object path) Cast INode to INodeDirectory.

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

addAclFeature, addFeature, addXAttrFeature, getAclFeature, getFeature, getFeatures, getFsPermissionShort, getId, getLocalNameBytes, getNext, getPermissionLong, removeAclFeature, removeFeature, removeXAttrFeature, setAccessTime, setLocalName, setModificationTime, setNext, updateModificationTime

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

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.hdfs.server.namenode.INodeAttributes

getAccessTime, getAclFeature, getFsPermission, getFsPermissionShort, getGroupName, getLocalNameBytes, getModificationTime, getPermissionLong, getUserName, getXAttrFeature

Field Detail

DEFAULT_FILES_PER_DIRECTORY

public static final int DEFAULT_FILES_PER_DIRECTORY

See Also:

Constant Field Values

Constructor Detail

INodeDirectory

public INodeDirectory(long id,
              byte[] name,
              org.apache.hadoop.fs.permission.PermissionStatus permissions,
              long mtime)

constructor

INodeDirectory

public INodeDirectory(INodeDirectory other,
              boolean adopt,
              INode.Feature... featuresToCopy)

Copy constructor

Parameters:

other - The INodeDirectory to be copied

adopt - Indicate whether or not need to set the parent field of child INodes to the new node

featuresToCopy - any number of features to copy to the new node. The method will do a reference copy, not a deep copy.

Method Detail

valueOf

public static INodeDirectory valueOf(org.apache.hadoop.hdfs.server.namenode.INode inode,
                     Object path)
                              throws FileNotFoundException,
                                     org.apache.hadoop.fs.PathIsNotDirectoryException

Cast INode to INodeDirectory.

Throws:

FileNotFoundException

org.apache.hadoop.fs.PathIsNotDirectoryException

isDirectory

public final boolean isDirectory()

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

Check whether it's a directory

Specified by:

isDirectory in interface org.apache.hadoop.hdfs.server.namenode.INodeAttributes

Overrides:

isDirectory in class org.apache.hadoop.hdfs.server.namenode.INode

Returns:

true unconditionally.

asDirectory

public final INodeDirectory asDirectory()

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

Cast this inode to an INodeDirectory.

Overrides:

asDirectory in class org.apache.hadoop.hdfs.server.namenode.INode

Returns:

this object.

getLocalStoragePolicyID

public byte getLocalStoragePolicyID()

Specified by:

getLocalStoragePolicyID in class org.apache.hadoop.hdfs.server.namenode.INode

Returns:

the storage policy directly specified on the INode. Return HdfsConstants.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED if no policy has been specified.

getStoragePolicyID

public byte getStoragePolicyID()

Specified by:

getStoragePolicyID in class org.apache.hadoop.hdfs.server.namenode.INode

Returns:

the latest block storage policy id of the INode. Specifically, if a storage policy is directly specified on the INode then return the ID of that policy. Otherwise follow the latest parental path and return the ID of the first specified storage policy.

getQuotaCounts

public QuotaCounts getQuotaCounts()

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

Get the quota set for this inode

Specified by:

getQuotaCounts in interface org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes

Overrides:

getQuotaCounts in class org.apache.hadoop.hdfs.server.namenode.INode

Returns:

the quota counts. The count is -1 if it is not set.

addSpaceConsumed

public void addSpaceConsumed(QuotaCounts counts,
                    boolean verify)
                      throws org.apache.hadoop.hdfs.protocol.QuotaExceededException

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

Check and add namespace/storagespace/storagetype consumed to itself and the ancestors.

Overrides:

addSpaceConsumed in class org.apache.hadoop.hdfs.server.namenode.INode

Throws:

org.apache.hadoop.hdfs.protocol.QuotaExceededException - if quote is violated.

getDirectoryWithQuotaFeature

public final DirectoryWithQuotaFeature getDirectoryWithQuotaFeature()

If the directory contains a DirectoryWithQuotaFeature, return it; otherwise, return null.

addSnapshotFeature

public org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature addSnapshotFeature(DirectoryWithSnapshotFeature.DirectoryDiffList diffs)

getDirectoryWithSnapshotFeature

public final org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature getDirectoryWithSnapshotFeature()

If feature list contains a DirectoryWithSnapshotFeature, return it; otherwise, return null.

isWithSnapshot

public final boolean isWithSnapshot()

Is this file has the snapshot feature?

getDiffs

public DirectoryWithSnapshotFeature.DirectoryDiffList getDiffs()

getSnapshotINode

public org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes getSnapshotINode(int snapshotId)

Overrides:

getSnapshotINode in class org.apache.hadoop.hdfs.server.namenode.INode

Returns:

if the given snapshot id is Snapshot.CURRENT_STATE_ID, return this; otherwise return the corresponding snapshot inode.

toDetailString

public String toDetailString()

Overrides:

toDetailString in class org.apache.hadoop.hdfs.server.namenode.INode

getDirectorySnapshottableFeature

public org.apache.hadoop.hdfs.server.namenode.snapshot.DirectorySnapshottableFeature getDirectorySnapshottableFeature()

isSnapshottable

public boolean isSnapshottable()

getSnapshot

public org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot getSnapshot(byte[] snapshotName)

setSnapshotQuota

public void setSnapshotQuota(int snapshotQuota)

addSnapshot

public org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot addSnapshot(int id,
                                                                   String name)
                                                                     throws SnapshotException,
                                                                            org.apache.hadoop.hdfs.protocol.QuotaExceededException

Throws:

SnapshotException

org.apache.hadoop.hdfs.protocol.QuotaExceededException

removeSnapshot

public org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot removeSnapshot(INode.ReclaimContext reclaimContext,
                                                                      String snapshotName)
                                                                        throws SnapshotException

Throws:

SnapshotException

renameSnapshot

public void renameSnapshot(String path,
                  String oldName,
                  String newName)
                    throws SnapshotException

Throws:

SnapshotException

addSnapshottableFeature

public void addSnapshottableFeature()

add DirectorySnapshottableFeature

removeSnapshottableFeature

public void removeSnapshottableFeature()

remove DirectorySnapshottableFeature

replaceChild

public void replaceChild(org.apache.hadoop.hdfs.server.namenode.INode oldChild,
                org.apache.hadoop.hdfs.server.namenode.INode newChild,
                INodeMap inodeMap)

Replace the given child with a new child. Note that we no longer need to replace an normal INodeDirectory or INodeFile into an INodeDirectoryWithSnapshot or INodeFileUnderConstruction. The only cases for child replacement is for reference nodes.

recordModification

public void recordModification(int latestSnapshotId)

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

This inode is being modified. The previous version of the inode needs to be recorded in the latest snapshot.

Specified by:

recordModification in class org.apache.hadoop.hdfs.server.namenode.INode

Parameters:

latestSnapshotId - The id of the latest snapshot that has been taken. Note that it is Snapshot.CURRENT_STATE_ID if no snapshots have been taken.

saveChild2Snapshot

public org.apache.hadoop.hdfs.server.namenode.INode saveChild2Snapshot(org.apache.hadoop.hdfs.server.namenode.INode child,
                                                              int latestSnapshotId,
                                                              org.apache.hadoop.hdfs.server.namenode.INode snapshotCopy)

Save the child to the latest snapshot.

Returns:

the child inode, which may be replaced.

getChild

public org.apache.hadoop.hdfs.server.namenode.INode getChild(byte[] name,
                                                    int snapshotId)

Parameters:

name - the name of the child

snapshotId - if it is not Snapshot.CURRENT_STATE_ID, get the result from the corresponding snapshot; otherwise, get the result from the current directory.

Returns:

the child inode.

searchChild

public int searchChild(org.apache.hadoop.hdfs.server.namenode.INode inode)

Search for the given INode in the children list and the deleted lists of snapshots.

Returns:

Snapshot.CURRENT_STATE_ID if the inode is in the children list; Snapshot.NO_SNAPSHOT_ID if the inode is neither in the children list nor in any snapshot; otherwise the snapshot id of the corresponding snapshot diff list.

getChildrenList

public org.apache.hadoop.hdfs.util.ReadOnlyList<org.apache.hadoop.hdfs.server.namenode.INode> getChildrenList(int snapshotId)

Parameters:

snapshotId - if it is not Snapshot.CURRENT_STATE_ID, get the result from the corresponding snapshot; otherwise, get the result from the current directory.

Returns:

the current children list if the specified snapshot is null; otherwise, return the children list corresponding to the snapshot. Note that the returned list is never null.

removeChild

public boolean removeChild(org.apache.hadoop.hdfs.server.namenode.INode child,
                  int latestSnapshotId)

Remove the specified child from this directory.

removeChild

public boolean removeChild(org.apache.hadoop.hdfs.server.namenode.INode child)

Remove the specified child from this directory. The basic remove method which actually calls children.remove(..).

Parameters:

child - the child inode to be removed

Returns:

true if the child is removed; false if the child is not found.

addChild

public boolean addChild(org.apache.hadoop.hdfs.server.namenode.INode node,
               boolean setModTime,
               int latestSnapshotId)
                 throws org.apache.hadoop.hdfs.protocol.QuotaExceededException

Add a child inode to the directory.

Parameters:

node - INode to insert

setModTime - set modification time for the parent node not needed when replaying the addition and the parent already has the proper mod time

Returns:

false if the child with this name already exists; otherwise, return true;

Throws:

org.apache.hadoop.hdfs.protocol.QuotaExceededException

addChild

public boolean addChild(org.apache.hadoop.hdfs.server.namenode.INode node)

computeQuotaUsage

public QuotaCounts computeQuotaUsage(BlockStoragePolicySuite bsps,
                            byte blockStoragePolicyId,
                            boolean useCache,
                            int lastSnapshotId)

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

Count subtree Quota.NAMESPACE and Quota.STORAGESPACE usages. With the existence of INodeReference, the same inode and its subtree may be referred by multiple INodeReference.WithName nodes and a INodeReference.DstReference node. To avoid circles while quota usage computation, we have the following rules:

 1. For a INodeReference.DstReference node, since the node must be in the current
 tree (or has been deleted as the end point of a series of rename 
 operations), we compute the quota usage of the referred node (and its 
 subtree) in the regular manner, i.e., including every inode in the current
 tree and in snapshot copies, as well as the size of diff list.
 
 2. For a INodeReference.WithName node, since the node must be in a snapshot, we 
 only count the quota usage for those nodes that still existed at the 
 creation time of the snapshot associated with the INodeReference.WithName node.
 We do not count in the size of the diff list.  
 

Specified by:

computeQuotaUsage in class org.apache.hadoop.hdfs.server.namenode.INode

Parameters:

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

blockStoragePolicyId - block storage policy id of the current INode

useCache - Whether to use cached quota usage. Note that INodeReference.WithName node never uses cache for its subtree.

lastSnapshotId - Snapshot.CURRENT_STATE_ID indicates the computation is in the current tree. Otherwise the id indicates the computation range for a INodeReference.WithName node.

Returns:

The subtree quota counts.

computeQuotaUsage4CurrentDirectory

public QuotaCounts computeQuotaUsage4CurrentDirectory(BlockStoragePolicySuite bsps,
                                             byte storagePolicyId,
                                             QuotaCounts counts)

Add quota usage for this inode excluding children.

computeContentSummary

public org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext computeContentSummary(int snapshotId,
                                                                                            org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext summary)

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

Count subtree content summary with a ContentCounts.

Specified by:

computeContentSummary in class org.apache.hadoop.hdfs.server.namenode.INode

Parameters:

snapshotId - Specify the time range for the calculation. If this parameter equals to Snapshot.CURRENT_STATE_ID, the result covers both the current states and all the snapshots. Otherwise the result only covers all the files/directories contained in the specific snapshot.

summary - the context object holding counts for the subtree.

Returns:

The same objects as summary.

computeDirectoryContentSummary

protected org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext computeDirectoryContentSummary(org.apache.hadoop.hdfs.server.namenode.ContentSummaryComputationContext summary,
                                                                                                     int snapshotId)

undoRename4ScrParent

public void undoRename4ScrParent(INodeReference oldChild,
                        org.apache.hadoop.hdfs.server.namenode.INode newChild)
                          throws org.apache.hadoop.hdfs.protocol.QuotaExceededException

This method is usually called by the undo section of rename. Before calling this function, in the rename operation, we replace the original src node (of the rename operation) with a reference node (WithName instance) in both the children list and a created list, delete the reference node from the children list, and add it to the corresponding deleted list. To undo the above operations, we have the following steps in particular:

 1) remove the WithName node from the deleted list (if it exists) 
 2) replace the WithName node in the created list with srcChild 
 3) add srcChild back as a child of srcParent. Note that we already add 
 the node into the created list of a snapshot diff in step 2, we do not need
 to add srcChild to the created list of the latest snapshot.
 

We do not need to update quota usage because the old child is in the deleted list before.

Parameters:

oldChild - The reference node to be removed/replaced

newChild - The node to be added back

Throws:

org.apache.hadoop.hdfs.protocol.QuotaExceededException - should not throw this exception

undoRename4DstParent

public void undoRename4DstParent(BlockStoragePolicySuite bsps,
                        org.apache.hadoop.hdfs.server.namenode.INode deletedChild,
                        int latestSnapshotId)
                          throws org.apache.hadoop.hdfs.protocol.QuotaExceededException

Undo the rename operation for the dst tree, i.e., if the rename operation (with OVERWRITE option) removes a file/dir from the dst tree, add it back and delete possible record in the deleted list.

Throws:

org.apache.hadoop.hdfs.protocol.QuotaExceededException

clearChildren

public void clearChildren()

Set the children list to null.

clear

public void clear()

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

Clear references to other objects.

Overrides:

clear in class org.apache.hadoop.hdfs.server.namenode.INode

cleanSubtreeRecursively

public void cleanSubtreeRecursively(INode.ReclaimContext reclaimContext,
                           int snapshot,
                           int prior,
                           Map<org.apache.hadoop.hdfs.server.namenode.INode,org.apache.hadoop.hdfs.server.namenode.INode> excludedNodes)

Call cleanSubtree(..) recursively down the subtree.

destroyAndCollectBlocks

public void destroyAndCollectBlocks(INode.ReclaimContext reclaimContext)

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

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.

Specified by:

destroyAndCollectBlocks in class org.apache.hadoop.hdfs.server.namenode.INode

Parameters:

reclaimContext - Record blocks and inodes that need to be reclaimed.

cleanSubtree

public void cleanSubtree(INode.ReclaimContext reclaimContext,
                int snapshotId,
                int priorSnapshotId)

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.
 

Specified by:

cleanSubtree in class org.apache.hadoop.hdfs.server.namenode.INode

Parameters:

reclaimContext - Record blocks and inodes that need to be reclaimed.

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

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

metadataEquals

public boolean metadataEquals(org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes other)

Compare the metadata with another INodeDirectory

Specified by:

metadataEquals in interface org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes

dumpTreeRecursively

public void dumpTreeRecursively(PrintWriter out,
                       StringBuilder prefix,
                       int snapshot)

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

Dump tree recursively.

Overrides:

dumpTreeRecursively in class org.apache.hadoop.hdfs.server.namenode.INode

prefix - The prefix string that each line should print.

dumpTreeRecursively

public static void dumpTreeRecursively(PrintWriter out,
                       StringBuilder prefix,
                       Iterable<INodeDirectory.SnapshotAndINode> subs)

Dump the given subtrees.

Parameters:

prefix - The prefix string that each line should print.

subs - The subtrees.

getChildrenNum

public final int getChildrenNum(int snapshotId)