alluxio.worker.dora

Class DoraMetaManager

java.lang.Object

alluxio.worker.dora.DoraMetaManager

All Implemented Interfaces:

Closeable, AutoCloseable

public class DoraMetaManager
extends Object
implements Closeable

The Dora metadata manager that orchestrates the metadata operations. TODO(elega) Invalidating page cache synchronously causes performance issue and currently it also lacks concurrency control. Address this problem in the future.

Constructor Summary

Constructors

Constructor and Description
DoraMetaManager(AlluxioConfiguration conf, PagedDoraWorker doraWorker, CacheManager cacheManger, DoraUfsManager ufsManager) Creates a dora meta manager.

Method Summary

Modifier and Type	Method and Description
void	close()
Optional<DoraMeta.FileStatus>	getFromMetaStore(String path) Gets file meta from the metastore.
Optional<DoraMeta.FileStatus>	getFromUfs(String path) Gets file meta from UFS.
void	invalidateListingCache(String path) Invalidates the listing cache of a given path.
void	invalidateListingCacheOfParent(String path) Invalidates the listing cache of its parent of a given path.
Optional<ListStatusResult>	listCached(String path, boolean isRecursive) Get the cached listing result from the listing cache.
Optional<UfsStatus[]>	listFromUfs(String path, boolean isRecursive) Lists a directory from UFS.
Optional<UfsStatus[]>	listFromUfsThenCache(String path, boolean isRecursive) Lists a directory from UFS and cache it into the listing cache if it exists.
Optional<DoraMeta.FileStatus>	loadFromUfs(String path) Gets file meta from UFS and loads it into metastore if exists.
void	put(String path, DoraMeta.FileStatus status) Puts meta of a file into the metastore, and invalidates the file data cache.
Optional<DoraMeta.FileStatus>	removeFromMetaStore(String path) Removes meta of a file from the meta store.

Methods inherited from class java.lang.Object

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

Constructor Detail

DoraMetaManager

public DoraMetaManager(AlluxioConfiguration conf,
                       PagedDoraWorker doraWorker,
                       CacheManager cacheManger,
                       DoraUfsManager ufsManager)

Creates a dora meta manager.

Parameters:

conf - configuration

doraWorker - the dora worker instance

cacheManger - the cache manager to manage the page cache

ufsManager - the ufs Manager

Method Detail

getFromUfs

public Optional<DoraMeta.FileStatus> getFromUfs(String path)
                                         throws IOException

Gets file meta from UFS.

Parameters:

path - the full ufs path

Returns:

the file status, or empty optional if not found

Throws:

IOException

loadFromUfs

public Optional<DoraMeta.FileStatus> loadFromUfs(String path)
                                          throws IOException

Gets file meta from UFS and loads it into metastore if exists. If the file does not exist in the UFS, clean up metadata and data.

Parameters:

path - the full ufs path

Returns:

the file status, or empty optional if not found

Throws:

IOException

getFromMetaStore

public Optional<DoraMeta.FileStatus> getFromMetaStore(String path)

Gets file meta from the metastore.

Parameters:

path - the full ufs path

Returns:

the file status, or empty optional if not found

put

public void put(String path,
                DoraMeta.FileStatus status)

Puts meta of a file into the metastore, and invalidates the file data cache.

Parameters:

path - the full ufs path

status - the file meta

removeFromMetaStore

public Optional<DoraMeta.FileStatus> removeFromMetaStore(String path)

Removes meta of a file from the meta store.

Parameters:

path - the full ufs path

Returns:

the removed file meta, if exists

invalidateListingCache

public void invalidateListingCache(String path)

Invalidates the listing cache of a given path.

Parameters:

path - the full ufs path

invalidateListingCacheOfParent

public void invalidateListingCacheOfParent(String path)

Invalidates the listing cache of its parent of a given path. If root is specified, the listing cache of root itself will be invalidated.

Parameters:

path - the full ufs path

listCached

public Optional<ListStatusResult> listCached(String path,
                                             boolean isRecursive)

Get the cached listing result from the listing cache.

Parameters:

path - the full ufs path to list

isRecursive - if the list is recursive

Returns:

an Optional of a listStatusResult object. If the object exists but the ufs status is empty, it means that the directory does not exist.

listFromUfsThenCache

public Optional<UfsStatus[]> listFromUfsThenCache(String path,
                                                  boolean isRecursive)
                                           throws IOException

Lists a directory from UFS and cache it into the listing cache if it exists.

Parameters:

path - the ufs path

isRecursive - if the listing is recursive

Returns:

an empty option if the directory does not exist or the path does not denote a directory, otherwise an option contains an ufs status array.

Throws:

IOException - if the UFS call failed

listFromUfs

public Optional<UfsStatus[]> listFromUfs(String path,
                                         boolean isRecursive)
                                  throws IOException

Lists a directory from UFS.

Parameters:

path - the ufs path

isRecursive - if the listing is recursive

Returns:

an empty option if the directory does not exist or the path does not denote a directory, otherwise an option contains an ufs status array.

Throws:

IOException - if the UFS call failed

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException