Package alluxio.util

Class IdUtils

java.lang.Object

alluxio.util.IdUtils

@ThreadSafe
public final class IdUtils
extends java.lang.Object

Utility methods for working with an id in Alluxio.

Field Summary

Fields

Modifier and Type	Field	Description
static long	INVALID_FILE_ID
static long	INVALID_MOUNT_ID
static long	INVALID_WORKER_ID
static long	ROOT_MOUNT_ID
static long	UFS_JOURNAL_MOUNT_ID	The journal ufs is stored as a special mount in the ufs manage.

Method Summary

Modifier and Type	Method	Description
static long	createFileId(long containerId)	Creates an id for a file based on the given id of the container.
static java.lang.String	createFileSystemContextId()
static long	createMountId()
static java.lang.String	createOrGetAppIdFromConfig(AlluxioConfiguration conf)
static java.lang.String	createRpcId()
static long	createSessionId()
static long	fileIdFromBlockId(long blockId)	Creates a file ID from a block ID.
static long	getRandomNonNegativeLong()	Generates a positive random number by zero-ing the sign bit.

Methods inherited from class java.lang.Object

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

Field Detail

INVALID_FILE_ID

public static final long INVALID_FILE_ID

See Also:

Constant Field Values

INVALID_WORKER_ID

public static final long INVALID_WORKER_ID

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Constant Field Values

INVALID_MOUNT_ID

public static final long INVALID_MOUNT_ID

See Also:

Constant Field Values

ROOT_MOUNT_ID

public static final long ROOT_MOUNT_ID

See Also:

Constant Field Values

UFS_JOURNAL_MOUNT_ID

public static final long UFS_JOURNAL_MOUNT_ID

The journal ufs is stored as a special mount in the ufs manage.

See Also:

Constant Field Values

Method Detail

createFileId

public static long createFileId(long containerId)

Creates an id for a file based on the given id of the container.

Parameters:

containerId - the id of the container

Returns:

a file id based on the given container id

fileIdFromBlockId

public static long fileIdFromBlockId(long blockId)

Creates a file ID from a block ID.

Parameters:

blockId - the block ID

Returns:

the file ID

createRpcId

public static java.lang.String createRpcId()

Returns:

the created RPC id

getRandomNonNegativeLong

public static long getRandomNonNegativeLong()

Generates a positive random number by zero-ing the sign bit.

Returns:

a random long which is guaranteed to be non negative (zero is allowed)

createSessionId

public static long createSessionId()

Returns:

a session ID

createMountId

public static long createMountId()

Returns:

a random long which is guaranteed to be non negative (zero is allowed)

createFileSystemContextId

public static java.lang.String createFileSystemContextId()

Returns:

app suffixed by a positive random long

createOrGetAppIdFromConfig

public static java.lang.String createOrGetAppIdFromConfig(AlluxioConfiguration conf)

Parameters:

conf - an alluxio configuration with the USER_APP_ID property key

Returns:

a string representing the USER_APP_ID