alluxio.master.file.meta

Class MountTable

java.lang.Object

alluxio.master.file.meta.MountTable

All Implemented Interfaces:

JournalEntryIterable

@ThreadSafe
public final class MountTable
extends Object
implements JournalEntryIterable

This class is used for keeping track of Alluxio mount points.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	MountTable.Resolution This class represents a UFS path after resolution.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ROOT

Constructor Summary

Constructors

Constructor and Description
MountTable(UfsManager ufsManager) Creates a new instance of MountTable.

Method Summary

Modifier and Type	Method and Description
void	add(AlluxioURI alluxioUri, AlluxioURI ufsUri, long mountId, MountOptions options) Mounts the given UFS path at the given Alluxio path.
void	checkUnderWritableMountPoint(AlluxioURI alluxioUri) Checks to see if a write operation is allowed for the specified Alluxio path, by determining if it is under a readonly mount point.
void	clear() Clears all the mount points except the root.
boolean	containsMountPoint(AlluxioURI uri)
boolean	delete(AlluxioURI uri) Unmounts the given Alluxio path.
Iterator<Journal.JournalEntry>	getJournalEntryIterator()
MountInfo	getMountInfo(long mountId)
String	getMountPoint(AlluxioURI uri) Returns the closest ancestor mount point the given path is nested under.
Map<String,MountInfo>	getMountTable() Returns a copy of the current mount table, the mount table is a map from Alluxio file system URIs to the corresponding mount point information.
boolean	isMountPoint(AlluxioURI uri)
MountTable.Resolution	resolve(AlluxioURI uri) Resolves the given Alluxio path.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ROOT

public static final String ROOT

See Also:

Constant Field Values

Constructor Detail

MountTable

public MountTable(UfsManager ufsManager)

Creates a new instance of MountTable.

Parameters:

ufsManager - the UFS manager

Method Detail

getJournalEntryIterator

public Iterator<Journal.JournalEntry> getJournalEntryIterator()

Specified by:

getJournalEntryIterator in interface JournalEntryIterable

Returns:

an Iterator that iterates all the journal entries

add

public void add(AlluxioURI alluxioUri,
                AlluxioURI ufsUri,
                long mountId,
                MountOptions options)
         throws FileAlreadyExistsException,
                InvalidPathException

Mounts the given UFS path at the given Alluxio path. The Alluxio path should not be nested under an existing mount point.

Parameters:

alluxioUri - an Alluxio path URI

ufsUri - a UFS path URI

mountId - the mount id

options - the mount options

Throws:

FileAlreadyExistsException - if the mount point already exists

InvalidPathException - if an invalid path is encountered

clear

public void clear()

Clears all the mount points except the root.

delete

public boolean delete(AlluxioURI uri)

Unmounts the given Alluxio path. The path should match an existing mount point.

Parameters:

uri - an Alluxio path URI

Returns:

whether the operation succeeded or not

getMountPoint

public String getMountPoint(AlluxioURI uri)
                     throws InvalidPathException

Returns the closest ancestor mount point the given path is nested under.

Parameters:

uri - an Alluxio path URI

Returns:

mount point the given Alluxio path is nested under

Throws:

InvalidPathException - if an invalid path is encountered

getMountTable

public Map<String,MountInfo> getMountTable()

Returns a copy of the current mount table, the mount table is a map from Alluxio file system URIs to the corresponding mount point information.

Returns:

a copy of the current mount table

containsMountPoint

public boolean containsMountPoint(AlluxioURI uri)
                           throws InvalidPathException

Parameters:

uri - the Alluxio uri to check

Returns:

true if the specified uri is mount point, or has a descendant which is a mount point

Throws:

InvalidPathException

isMountPoint

public boolean isMountPoint(AlluxioURI uri)

Parameters:

uri - an Alluxio path URI

Returns:

whether the given uri is a mount point

resolve

public MountTable.Resolution resolve(AlluxioURI uri)
                              throws InvalidPathException

Resolves the given Alluxio path. If the given Alluxio path is nested under a mount point, the resolution maps the Alluxio path to the corresponding UFS path. Otherwise, the resolution is a no-op.

Parameters:

uri - an Alluxio path URI

Returns:

the MountTable.Resolution representing the UFS path

Throws:

InvalidPathException - if an invalid path is encountered

checkUnderWritableMountPoint

public void checkUnderWritableMountPoint(AlluxioURI alluxioUri)
                                  throws InvalidPathException,
                                         AccessControlException

Checks to see if a write operation is allowed for the specified Alluxio path, by determining if it is under a readonly mount point.

Parameters:

alluxioUri - an Alluxio path URI

Throws:

InvalidPathException - if the Alluxio path is invalid

AccessControlException - if the Alluxio path is under a readonly mount point

getMountInfo

@Nullable
public MountInfo getMountInfo(long mountId)

Parameters:

mountId - the given ufs id

Returns:

the mount information with this id or null if this mount id is not found