alluxio.fuse

Class AlluxioFuseUtils

java.lang.Object

alluxio.fuse.AlluxioFuseUtils

@ThreadSafe
public final class AlluxioFuseUtils
extends Object

Utility methods for Alluxio-FUSE.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AlluxioFuseUtils.FuseCallable An interface representing a callable for FUSE APIs.

Field Summary

Fields

Modifier and Type	Field and Description
static long	ID_NOT_SET_VALUE
static long	ID_NOT_SET_VALUE_UNSIGNED
static String	INVALID_USER_GROUP_NAME
static int	MAX_NAME_LENGTH Most FileSystems on linux limit the length of file name beyond 255 characters.
static long	MODE_NOT_SET_VALUE

Method Summary

Modifier and Type	Method and Description
static int	call(org.slf4j.Logger logger, AlluxioFuseUtils.FuseCallable callable, String methodName, String description, Object... args) Calls the given AlluxioFuseUtils.FuseCallable and returns its result.
static int	checkFileLength(AlluxioURI uri) Checks the input file length.
static FileOutStream	createFile(FileSystem fileSystem, AuthPolicy authPolicy, AlluxioURI uri, long mode) Creates a file in alluxio namespace.
static void	deletePath(FileSystem fileSystem, AlluxioURI uri) Deletes a file or a directory in alluxio namespace.
static int	getErrorCode(Throwable t) Gets the corresponding error code of a throwable.
static Optional<Long>	getGidFromGroupName(String groupName) Retrieves the gid of the given group.
static Optional<Long>	getGidFromUserName(String userName) Retrieves the primary gid of the given user.
static Optional<String>	getGroupName(long gid) Gets the group name from the group id.
static Optional<String>	getGroupName(String userName) Gets the primary group name from the user name.
static Optional<URIStatus>	getPathStatus(FileSystem fileSystem, AlluxioURI uri) Gets the path status.
static long	getSystemGid()
static long	getSystemUid()
static Optional<Long>	getUid(String userName) Retrieves the uid of the given user.
static Optional<String>	getUserName(long uid) Gets the user name from the user id.
static VersionPreference	getVersionPreference(AlluxioConfiguration conf) Gets the libjnifuse version preference set by user.
static boolean	isFuseInstalled() Checks whether fuse is installed in local file system.
static void	setAttribute(FileSystem fileSystem, AlluxioURI uri, SetAttributePOptions options) Sets attribute for a file.
static AlluxioConfiguration	tryLoadingConfigFromMaster(FileSystemContext fsContext) Tries to laod Alluxio config from Alluxio Master through Grpc.
static Optional<URIStatus>	waitForFileCompleted(FileSystem fileSystem, AlluxioURI uri) Waits for the file to complete.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_NAME_LENGTH

public static final int MAX_NAME_LENGTH

Most FileSystems on linux limit the length of file name beyond 255 characters.

See Also:

Constant Field Values

INVALID_USER_GROUP_NAME

public static final String INVALID_USER_GROUP_NAME

See Also:

Constant Field Values

ID_NOT_SET_VALUE

public static final long ID_NOT_SET_VALUE

See Also:

Constant Field Values

ID_NOT_SET_VALUE_UNSIGNED

public static final long ID_NOT_SET_VALUE_UNSIGNED

See Also:

Constant Field Values

MODE_NOT_SET_VALUE

public static final long MODE_NOT_SET_VALUE

See Also:

Constant Field Values

Method Detail

checkFileLength

public static int checkFileLength(AlluxioURI uri)

Checks the input file length.

Parameters:

uri - the Alluxio URI

Returns:

error code if file length is not allowed, 0 otherwise

createFile

public static FileOutStream createFile(FileSystem fileSystem,
                                       AuthPolicy authPolicy,
                                       AlluxioURI uri,
                                       long mode)

Creates a file in alluxio namespace.

Parameters:

fileSystem - the file system

authPolicy - the authentication policy

uri - the alluxio uri

mode - the create mode

Returns:

a file out stream

deletePath

public static void deletePath(FileSystem fileSystem,
                              AlluxioURI uri)

Deletes a file or a directory in alluxio namespace.

Parameters:

fileSystem - the file system

uri - the alluxio uri

setAttribute

public static void setAttribute(FileSystem fileSystem,
                                AlluxioURI uri,
                                SetAttributePOptions options)

Sets attribute for a file.

Parameters:

fileSystem - the file system

uri - the alluxio uri

options - the set attribute options

getVersionPreference

public static VersionPreference getVersionPreference(AlluxioConfiguration conf)

Gets the libjnifuse version preference set by user.

Parameters:

conf - the configuration object

Returns:

the version preference

tryLoadingConfigFromMaster

public static AlluxioConfiguration tryLoadingConfigFromMaster(FileSystemContext fsContext)

Tries to laod Alluxio config from Alluxio Master through Grpc.

Parameters:

fsContext - for communicating with master

Returns:

the Alluxio config if loaded successfully; the unmodified conf otherwise

getSystemUid

public static long getSystemUid()

Returns:

the system uid

getSystemGid

public static long getSystemGid()

Returns:

the system gid

getUid

public static Optional<Long> getUid(String userName)

Retrieves the uid of the given user.

Parameters:

userName - the user name

Returns:

uid

getGidFromUserName

public static Optional<Long> getGidFromUserName(String userName)

Retrieves the primary gid of the given user.

Parameters:

userName - the user name

Returns:

gid

getGidFromGroupName

public static Optional<Long> getGidFromGroupName(String groupName)

Retrieves the gid of the given group.

Parameters:

groupName - the group name

Returns:

gid

getUserName

public static Optional<String> getUserName(long uid)

Gets the user name from the user id.

Parameters:

uid - user id

Returns:

user name

getGroupName

public static Optional<String> getGroupName(String userName)

Gets the primary group name from the user name.

Parameters:

userName - the user name

Returns:

group name

getGroupName

public static Optional<String> getGroupName(long gid)

Gets the group name from the group id.

Parameters:

gid - the group id

Returns:

group name

isFuseInstalled

public static boolean isFuseInstalled()

Checks whether fuse is installed in local file system. Alluxio-Fuse only support mac and linux.

Returns:

true if fuse is installed, false otherwise

getErrorCode

public static int getErrorCode(Throwable t)

Gets the corresponding error code of a throwable.

Parameters:

t - throwable

Returns:

the corresponding error code

getPathStatus

public static Optional<URIStatus> getPathStatus(FileSystem fileSystem,
                                                AlluxioURI uri)

Gets the path status.

Parameters:

fileSystem - the file system

uri - the Alluxio uri to get status of

Returns:

the file status

waitForFileCompleted

public static Optional<URIStatus> waitForFileCompleted(FileSystem fileSystem,
                                                       AlluxioURI uri)

Waits for the file to complete. This method is mainly added to make sure the async release() when writing a file finished before getting status of the file or opening the file for read().

Parameters:

fileSystem - the file system to get file status

uri - the file path to check

Returns:

uri status if file is completed and empty otherwise

call

public static int call(org.slf4j.Logger logger,
                       AlluxioFuseUtils.FuseCallable callable,
                       String methodName,
                       String description,
                       Object... args)

Calls the given AlluxioFuseUtils.FuseCallable and returns its result.

Parameters:

logger - the logger to use for this call

callable - the callable to call

methodName - the name of the method, used for metrics

description - the format string of the description, used for logging

args - the arguments for the description

Returns:

the result