com.illumon.iris.db.util.liveness

Class LivenessScopeStack

java.lang.Object

com.illumon.iris.db.util.liveness.LivenessScopeStack

public class LivenessScopeStack
extends Object

Support for a thread-local stack of LivenessScopes to allow the preferred programming model for scoping of LivenessArtifacts.

Instances expect to be used on exactly one thread, and hence do not take any measures to ensure thread safety.

Method Summary

Modifier and Type	Method and Description
static SafeCloseable	open() Push an anonymous scope onto the scope stack, and get an SafeCloseable that pops it and then LivenessScope.release()s it.
static SafeCloseable	open(LivenessScope scope, boolean releaseOnClose) Push a scope onto the scope stack, and get an SafeCloseable that pops it.
static LivenessManager	peek() Get the scope at the top of the current thread's scope stack, or the base manager if no scopes have been pushed but not popped on this thread.
static void	pop(LivenessScope scope) Pop a scope from the current thread's scope stack.
static void	push(LivenessScope scope) Push a scope onto the current thread's scope stack.

Methods inherited from class java.lang.Object

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

Method Detail

push

public static void push(@NotNull
                        LivenessScope scope)

Push a scope onto the current thread's scope stack.

Parameters:

scope - The scope

pop

public static void pop(@NotNull
                       LivenessScope scope)

Pop a scope from the current thread's scope stack.

Must be the current top of the stack.

Parameters:

scope - The scope

peek

@NotNull
public static LivenessManager peek()

Get the scope at the top of the current thread's scope stack, or the base manager if no scopes have been pushed but not popped on this thread.

This method defines the manager that should be used for all new LivenessArtifacts.

Returns:

The current manager

open

@NotNull
public static SafeCloseable open(@NotNull
                                          LivenessScope scope,
                                          boolean releaseOnClose)

Push a scope onto the scope stack, and get an SafeCloseable that pops it.

This is useful for enclosing scope usage in a try-with-resources block.

Parameters:

scope - The scope

releaseOnClose - Whether the scope should be released when the result is closed

Returns:

A SafeCloseable whose SafeCloseable.close() method invokes LivenessScopeStack.pop(LivenessScope) for the scope (followed by LivenessScope.release() if releaseOnClose is true)

open

@NotNull
public static SafeCloseable open()

Push an anonymous scope onto the scope stack, and get an SafeCloseable that pops it and then LivenessScope.release()s it.

This is useful enclosing a series of query engine actions whose results must be explicitly retained externally in order to preserve liveness.

Returns:

A SafeCloseable whose SafeCloseable.close() method invokes LivenessScopeStack.pop(LivenessScope) for the scope, followed by LivenessScope.release()