water

Class Scope

java.lang.Object

water.Scope

public class Scope
extends java.lang.Object

A "scope" for tracking Key lifetimes; an experimental API.

A Scope defines a SINGLE THREADED local lifetime management context, stored in Thread Local Storage. Scopes can be explicitly entered or exited. User keys created by this thread are tracked, and deleted when the scope is exited. Since enter & exit are explicit, failure to exit means the Keys leak (there is no reliable thread-on-exit cleanup action). You must call Scope.exit() at some point. Only user keys & Vec keys are tracked.

Scopes support nesting. Scopes support partial cleanup: you can list Keys you'd like to keep in the exit() call. These will be "bumped up" to the higher nested scope - or escaped and become untracked at the top-level.

Constructor Summary

Constructors

Constructor and Description
Scope()

Method Summary

Modifier and Type	Method and Description
static Scope	current() debugging purpose
static void	enter() Enter a new Scope
static Key[]	exit(Key... keep) Exit the inner-most Scope, remove all Keys created since the matching enter call except for the listed Keys.
static boolean	isActive() Pop-scope (same as exit-scope) but return all keys that are tracked (and would have been deleted).
static <T extends Keyed<T>> T	track_generic(T keyed)
static Frame	track(Frame... frames) Track one or more Frames, and return the first one.
static Vec	track(Vec vec)
static void	untrack(Frame... frames)
static <K extends Keyed> void	untrack(java.lang.Iterable<Key<K>> keys)
static <K extends Keyed> void	untrack(Key<K>... keys)

Methods inherited from class java.lang.Object

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

Constructor Detail

Scope

public Scope()

Method Detail

current

public static Scope current()

debugging purpose

enter

public static void enter()

Enter a new Scope

exit

public static Key[] exit(Key... keep)

Exit the inner-most Scope, remove all Keys created since the matching enter call except for the listed Keys.

Returns:

Returns the list of kept keys.

isActive

public static boolean isActive()

Pop-scope (same as exit-scope) but return all keys that are tracked (and would have been deleted).

track_generic

public static <T extends Keyed<T>> T track_generic(T keyed)

track

public static Vec track(Vec vec)

track

public static Frame track(Frame... frames)

Track one or more Frames, and return the first one. The tracked frames will be removed from DKV when exit(Key[]) is called.

untrack

public static <K extends Keyed> void untrack(Key<K>... keys)

untrack

public static <K extends Keyed> void untrack(java.lang.Iterable<Key<K>> keys)

untrack

public static void untrack(Frame... frames)