reactor.core

Interface Fuseable

All Known Implementing Classes:

Operators.MonoSubscriber, ReplayProcessor, UnicastProcessor

public interface Fuseable

A micro API for stream fusion, in particular marks producers that support a Fuseable.QueueSubscription.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Fuseable.ConditionalSubscriber<T> A subscriber variant that can immediately tell if it consumed the value or not, directly allowing a new value to be sent if it didn't.
static interface	Fuseable.QueueSubscription<T> Support contract for queue-fusion based optimizations on subscriptions.
static interface	Fuseable.ScalarCallable<T> Marker interface indicating that the target can return a value or null, otherwise fail immediately and thus a viable target for assembly-time optimizations.
static interface	Fuseable.SynchronousSubscription<T> Base class for synchronous sources which have fixed size and can emit their items in a pull fashion, thus avoiding the request-accounting overhead in many cases.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ANY Indicates the QueueSubscription should decide what fusion it performs (input only).
static int	ASYNC Indicates the QueueSubscription can perform only async-fusion.
static int	NONE Indicates the QueueSubscription can't support the requested mode.
static int	SYNC Indicates the QueueSubscription can perform sync-fusion.
static int	THREAD_BARRIER Indicates that the queue will be drained from another thread thus any queue-exit computation may be invalid at that point.

Method Summary

Modifier and Type	Method and Description
static String	fusionModeName(int mode) Attempt to convert a fusion mode int code into a human-readable representation.
static String	fusionModeName(int mode, boolean ignoreThreadBarrier) Attempt to convert a fusion mode int code into a human-readable representation.

Field Detail

NONE

static final int NONE

Indicates the QueueSubscription can't support the requested mode.

See Also:

Constant Field Values

SYNC

static final int SYNC

Indicates the QueueSubscription can perform sync-fusion.

See Also:

Constant Field Values

ASYNC

static final int ASYNC

Indicates the QueueSubscription can perform only async-fusion.

See Also:

Constant Field Values

ANY

static final int ANY

Indicates the QueueSubscription should decide what fusion it performs (input only).

See Also:

Constant Field Values

THREAD_BARRIER

static final int THREAD_BARRIER

Indicates that the queue will be drained from another thread thus any queue-exit computation may be invalid at that point.

For example, an asyncSource.map().publishOn().subscribe() sequence where asyncSource is async-fuseable: publishOn may fuse the whole sequence into a single Queue. That in turn could invoke the mapper function from its poll() method from another thread, whereas the unfused sequence would have invoked the mapper on the previous thread. If such mapper invocation is costly, it would escape its thread boundary this way.

See Also:

Constant Field Values

Method Detail

fusionModeName

static String fusionModeName(int mode)

Attempt to convert a fusion mode int code into a human-readable representation. Note that this can include the THREAD_BARRIER flag, as an appended +THREAD_BARRIER.

This method accepts -1 as a special code, mainly for the benefit of supporting testing scenarios where fusion can be entirely deactivated (returns Disabled). Other negative values and unknown positive codes on the other hand return Unknown(x).

Note that as this is a human-facing representation, the different values could evolve in the future. As such, never compare the returned string to a constant, but always use this method on both sides of a comparison.

Parameters:

mode - the fusion mode int code

Returns:

a human-readable String representation of the code

fusionModeName

static String fusionModeName(int mode,
                             boolean ignoreThreadBarrier)

Attempt to convert a fusion mode int code into a human-readable representation. Note that this can include the THREAD_BARRIER flag, as an appended +THREAD_BARRIER, unless the ignoreThreadBarrier parameter is set to true.

This method accepts -1 as a special code, mainly for the benefit of supporting testing scenarios where fusion can be entirely deactivated (returns Disabled). Other negative values and unknown positive codes on the other hand return Unknown(x).

Note that as this is a human-facing representation, the different values could evolve in the future. As such, never compare the returned string to a constant, but always use this method on both sides of a comparison.

Parameters:

mode - the fusion mode int code

ignoreThreadBarrier - whether or not to ignore the THREAD_BARRIER flag in the representation

Returns:

a human-readable String representation of the code