Package org.apache.hadoop.fs

Class Options.HandleOpt

java.lang.Object

org.apache.hadoop.fs.Options.HandleOpt

Direct Known Subclasses:

Options.HandleOpt.Data, Options.HandleOpt.Location

Enclosing class:

Options

public static class Options.HandleOpt
extends java.lang.Object

Options for creating PathHandle references.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Options.HandleOpt.Data	Option storing standard constraints on data.
static class	Options.HandleOpt.Location	Option storing standard constraints on location.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	HandleOpt()

Method Summary

Modifier and Type	Method	Description
static Options.HandleOpt.Data	changed(boolean allow)
static Options.HandleOpt[]	content()	Handle is valid iff the content of the referent is the same.
static Options.HandleOpt[]	exact()	Handle is valid iff the referent is neither moved nor changed.
static <T extends Options.HandleOpt> java.util.Optional<T>	getOpt(java.lang.Class<T> c, Options.HandleOpt... opt)	Utility method to extract a HandleOpt from the set provided.
static Options.HandleOpt.Location	moved(boolean allow)
static Options.HandleOpt[]	path()	Handle is valid iff the referent is unmoved in the namespace.
static Options.HandleOpt[]	reference()	Handle is valid iff the referent exists in the namespace.
static java.util.function.Function<FileStatus,PathHandle>	resolve(java.util.function.BiFunction<FileStatus,Options.HandleOpt[],PathHandle> fsr, Options.HandleOpt... opt)	Utility function for partial evaluation of FileStatus instances to a fixed set of handle options.
static java.util.function.Function<FileStatus,PathHandle>	resolve(FileSystem fs, Options.HandleOpt... opt)	Utility function for mapping FileSystem.getPathHandle(org.apache.hadoop.fs.FileStatus, org.apache.hadoop.fs.Options.HandleOpt...) to a fixed set of handle options.

Methods inherited from class java.lang.Object

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

Constructor Detail

HandleOpt

protected HandleOpt()

Method Detail

resolve

public static java.util.function.Function<FileStatus,PathHandle> resolve(FileSystem fs,
                                                                               Options.HandleOpt... opt)

Utility function for mapping FileSystem.getPathHandle(org.apache.hadoop.fs.FileStatus, org.apache.hadoop.fs.Options.HandleOpt...) to a fixed set of handle options.

Parameters:

fs - Target filesystem

opt - Options to bind in partially evaluated function

Returns:

Function reference with options fixed

resolve

public static java.util.function.Function<FileStatus,PathHandle> resolve(java.util.function.BiFunction<FileStatus,Options.HandleOpt[],PathHandle> fsr,
                                                                               Options.HandleOpt... opt)

Utility function for partial evaluation of FileStatus instances to a fixed set of handle options.

Parameters:

fsr - Function reference

opt - Options to associate with FileStatus instances to produce PathHandle instances.

Returns:

Function reference with options fixed

exact

public static Options.HandleOpt[] exact()

Handle is valid iff the referent is neither moved nor changed. Equivalent to changed(false), moved(false).

Returns:

Options requiring that the content and location of the entity be unchanged between calls.

content

public static Options.HandleOpt[] content()

Handle is valid iff the content of the referent is the same. Equivalent to changed(false), moved(true).

Returns:

Options requiring that the content of the entity is unchanged, but it may be at a different location.

path

public static Options.HandleOpt[] path()

Handle is valid iff the referent is unmoved in the namespace. Equivalent to changed(true), moved(false).

Returns:

Options requiring that the referent exist in the same location, but its content may have changed.

reference

public static Options.HandleOpt[] reference()

Handle is valid iff the referent exists in the namespace. Equivalent to changed(true), moved(true).

Returns:

Options requiring that the implementation resolve a reference to this entity regardless of changes to content or location.

changed

public static Options.HandleOpt.Data changed(boolean allow)

Parameters:

allow - If true, resolve references to this entity even if it has been modified.

Returns:

Handle option encoding parameter.

moved

public static Options.HandleOpt.Location moved(boolean allow)

Parameters:

allow - If true, resolve references to this entity anywhere in the namespace.

Returns:

Handle option encoding parameter.

getOpt

public static <T extends Options.HandleOpt> java.util.Optional<T> getOpt(java.lang.Class<T> c,
                                                                         Options.HandleOpt... opt)

Utility method to extract a HandleOpt from the set provided.

Type Parameters:

T - Type constraint for exact match

Parameters:

c - Target class

opt - List of options

Returns:

An option assignable from the specified type or null if either opt is null or a suitable match is not found.

Throws:

java.lang.IllegalArgumentException - If more than one matching type is found.