alluxio.master.file.meta

Enum InodeTree.LockPattern

java.lang.Object

java.lang.Enum<InodeTree.LockPattern>

alluxio.master.file.meta.InodeTree.LockPattern

All Implemented Interfaces:

Serializable, Comparable<InodeTree.LockPattern>

Enclosing class:

InodeTree

public static enum InodeTree.LockPattern
extends Enum<InodeTree.LockPattern>

Patterns of inode path locking.

Enum Constant Summary

Enum Constants

Enum Constant and Description
READ Read lock every existing inode and edge along the path.
WRITE_EDGE Read lock every existing inode and edge along the path, but write lock the edge leading out of the last existing ancestor.
WRITE_INODE Read lock every existing inode and edge along the path, but write lock the final inode if it exists.

Method Summary

Modifier and Type	Method and Description
boolean	isWrite()
static InodeTree.LockPattern	valueOf(String name) Returns the enum constant of this type with the specified name.
static InodeTree.LockPattern[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

READ

public static final InodeTree.LockPattern READ

Read lock every existing inode and edge along the path. Useful when we want to read an inode without modifying anything. Examples path to lock: /a/b/c existing inodes: /a/b result: Read locks on [a, a->b, b] path to lock: /a/b/c existing inodes: /a/b/c result: Read locks on [a, a->b, b, b->c, c] path to lock: /a/b/c existing inodes: /a result: Read locks on [a]

WRITE_INODE

public static final InodeTree.LockPattern WRITE_INODE

Read lock every existing inode and edge along the path, but write lock the final inode if it exists. If the inode does not exist, read lock the edge leading out of the final existing ancestor. Useful when we want to modify an inode's metadata without changing the structure of the inode tree (no create/rename/delete). Examples path to lock: /a/b/c existing inodes: /a/b result: Read locks on [a, a->b, b, b->c] path to lock: /a/b/c existing inodes: /a/b/c result: Read locks on [a, a->b, b, b->c], Write locks on [c] path to lock: /a/b/c existing inodes: /a result: Read locks on [a, a->b]

WRITE_EDGE

public static final InodeTree.LockPattern WRITE_EDGE

Read lock every existing inode and edge along the path, but write lock the edge leading out of the last existing ancestor. Useful when we want to modify the structure of the inode tree, e.g. when creating, deleting, or renaming inodes. Examples path to lock: /a/b/c existing inodes: /a/b result: Read locks on [a, a->b, b], Write locks on [b->c] path to lock: /a/b/c existing inodes: /a/b/c result: Read locks on [a, a->b, b], Write locks on [b->c, c] path to lock: /a/b/c existing inodes: /a result: Read locks on [a], Write locks [a->b]

Method Detail

values

public static InodeTree.LockPattern[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (InodeTree.LockPattern c : InodeTree.LockPattern.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static InodeTree.LockPattern valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

isWrite

public boolean isWrite()

Returns:

whether the lock pattern is one of the write-type patterns