org.apache.hadoop.hdfs.server.namenode

Class INodeReference

java.lang.Object

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

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

All Implemented Interfaces:

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

Direct Known Subclasses:

INodeReference.DstReference, INodeReference.WithCount, INodeReference.WithName

public abstract class INodeReference
extends org.apache.hadoop.hdfs.server.namenode.INode

An anonymous reference to an inode. This class and its subclasses are used to support multiple access paths. A file/directory may have multiple access paths when it is stored in some snapshots and it is renamed/moved to other locations. For example, (1) Suppose we have /abc/foo, say the inode of foo is inode(id=1000,name=foo) (2) create snapshot s0 for /abc (3) mv /abc/foo /xyz/bar, i.e. inode(id=1000,name=...) is renamed from "foo" to "bar" and its parent becomes /xyz. Then, /xyz/bar and /abc/.snapshot/s0/foo are two different access paths to the same inode, inode(id=1000,name=bar). With references, we have the following - /abc has a child ref(id=1001,name=foo). - /xyz has a child ref(id=1002) - Both ref(id=1001,name=foo) and ref(id=1002) point to another reference, ref(id=1003,count=2). - Finally, ref(id=1003,count=2) points to inode(id=1000,name=bar). Note 1: For a reference without name, e.g. ref(id=1002), it uses the name of the referred inode. Note 2: getParent() always returns the parent in the current state, e.g. inode(id=1000,name=bar).getParent() returns /xyz but not /abc.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	INodeReference.DstReference
static class	INodeReference.WithCount An anonymous reference with reference count.
static class	INodeReference.WithName A reference with a fixed name.

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.INodeAttributes

INodeAttributes.SnapshotCopy

Field Summary

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

LOG

Constructor Summary

Constructors

Constructor and Description
INodeReference(org.apache.hadoop.hdfs.server.namenode.INode parent, org.apache.hadoop.hdfs.server.namenode.INode referred)

Method Summary

Methods

Modifier and Type	Method and Description
INodeDirectory	asDirectory() Cast this inode to an INodeDirectory.
org.apache.hadoop.hdfs.server.namenode.INodeFile	asFile() Cast this inode to an INodeFile.
INodeReference	asReference() Cast this inode to an INodeReference.
org.apache.hadoop.hdfs.server.namenode.INodeSymlink	asSymlink() Cast this inode to an INodeSymlink.
void	cleanSubtree(INode.ReclaimContext reclaimContext, int snapshot, int prior) Clean the subtree under this inode and collect the blocks from the descents for further block deletion/update.
void	clear() Clear references to other objects.
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.
QuotaCounts	computeQuotaUsage(BlockStoragePolicySuite bsps, byte blockStoragePolicyId, boolean useCache, int lastSnapshotId) Count subtree Quota.NAMESPACE and Quota.STORAGESPACE usages.
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.
long	getAccessTime(int snapshotId)
int	getDstSnapshotId()
org.apache.hadoop.fs.permission.FsPermission	getFsPermission(int snapshotId)
short	getFsPermissionShort()
String	getGroupName(int snapshotId)
long	getId() Get inode id
byte[]	getLocalNameBytes()
byte	getLocalStoragePolicyID()
long	getModificationTime(int snapshotId)
long	getPermissionLong()
org.apache.hadoop.fs.permission.PermissionStatus	getPermissionStatus(int snapshotId) Get the PermissionStatus
QuotaCounts	getQuotaCounts() Get the quota set for this inode
org.apache.hadoop.hdfs.server.namenode.INode	getReferredINode()
org.apache.hadoop.hdfs.server.namenode.INodeAttributes	getSnapshotINode(int snapshotId)
byte	getStoragePolicyID()
String	getUserName(int snapshotId)
boolean	isDirectory() Check whether it's a directory
boolean	isFile() Check whether it's a file.
boolean	isReference() Check whether it's a reference.
boolean	isSymlink() Check whether it's a symlink
void	setAccessTime(long accessTime) Set last access time of inode.
void	setLocalName(byte[] name) Set local file name
void	setModificationTime(long modificationTime) Set the last modification time of inode.
void	setReferredINode(org.apache.hadoop.hdfs.server.namenode.INode referred)
static int	tryRemoveReference(org.apache.hadoop.hdfs.server.namenode.INode inode) Try to remove the given reference and then return the reference count.
org.apache.hadoop.hdfs.server.namenode.INode	updateModificationTime(long mtime, int latestSnapshotId) Update modification time if it is larger than the current value.

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, 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

INodeReference

public INodeReference(org.apache.hadoop.hdfs.server.namenode.INode parent,
              org.apache.hadoop.hdfs.server.namenode.INode referred)

Method Detail

tryRemoveReference

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

Try to remove the given reference and then return the reference count. If the given inode is not a reference, return -1;

getReferredINode

public final org.apache.hadoop.hdfs.server.namenode.INode getReferredINode()

setReferredINode

public final void setReferredINode(org.apache.hadoop.hdfs.server.namenode.INode referred)

isReference

public final boolean isReference()

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

Check whether it's a reference.

Overrides:

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

asReference

public final INodeReference asReference()

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

Cast this inode to an INodeReference.

Overrides:

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

isFile

public final boolean isFile()

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

Check whether it's a file.

Overrides:

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

asFile

public final org.apache.hadoop.hdfs.server.namenode.INodeFile asFile()

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

Cast this inode to an INodeFile.

Overrides:

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

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

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

isSymlink

public final boolean isSymlink()

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

Check whether it's a symlink

Overrides:

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

asSymlink

public final org.apache.hadoop.hdfs.server.namenode.INodeSymlink asSymlink()

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

Cast this inode to an INodeSymlink.

Overrides:

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

getLocalNameBytes

public byte[] getLocalNameBytes()

Returns:

null if the local name is null; otherwise, return the local name byte array.

setLocalName

public void setLocalName(byte[] name)

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

Set local file name

Specified by:

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

getId

public final long getId()

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

Get inode id

Specified by:

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

getPermissionStatus

public final org.apache.hadoop.fs.permission.PermissionStatus getPermissionStatus(int snapshotId)

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

Get the PermissionStatus

Specified by:

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

getUserName

public final String getUserName(int snapshotId)

Specified by:

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

Parameters:

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

Returns:

user name

getGroupName

public final String getGroupName(int snapshotId)

Specified by:

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

Parameters:

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

Returns:

group name

getFsPermission

public final org.apache.hadoop.fs.permission.FsPermission getFsPermission(int snapshotId)

Specified by:

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

Parameters:

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

Returns:

permission.

getFsPermissionShort

public final short getFsPermissionShort()

Returns:

the permission as a short.

getPermissionLong

public long getPermissionLong()

Returns:

the permission information as a long.

getModificationTime

public final long getModificationTime(int snapshotId)

Specified by:

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

Parameters:

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

Returns:

modification time.

updateModificationTime

public final org.apache.hadoop.hdfs.server.namenode.INode updateModificationTime(long mtime,
                                                                  int latestSnapshotId)

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

Update modification time if it is larger than the current value.

Specified by:

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

setModificationTime

public final void setModificationTime(long modificationTime)

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

Set the last modification time of inode.

Specified by:

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

getAccessTime

public final long getAccessTime(int snapshotId)

Specified by:

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

Parameters:

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

Returns:

access time

setAccessTime

public final void setAccessTime(long accessTime)

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

Set last access time of inode.

Specified by:

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

getStoragePolicyID

public final 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.

getLocalStoragePolicyID

public final 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.

cleanSubtree

public void cleanSubtree(INode.ReclaimContext reclaimContext,
                int snapshot,
                int prior)

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.

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.

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.

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.

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.

getSnapshotINode

public final org.apache.hadoop.hdfs.server.namenode.INodeAttributes 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.

getQuotaCounts

public QuotaCounts getQuotaCounts()

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

Get the quota set for this inode

Overrides:

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

Returns:

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

clear

public final 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

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.

getDstSnapshotId

public int getDstSnapshotId()