Class AggregateFuture<InputT,OutputT>
java.lang.Object
com.google.common.util.concurrent.internal.InternalFutureFailureAccess
com.google.common.util.concurrent.AbstractFuture<OutputT>
com.google.common.util.concurrent.AbstractFuture.TrustedFuture<OutputT>
com.google.common.util.concurrent.AggregateFutureState<OutputT>
com.google.common.util.concurrent.AggregateFuture<InputT,OutputT>
- Type Parameters:
InputT
- the type of the individual inputsOutputT
- the type of the output (i.e. this) future
- All Implemented Interfaces:
AbstractFuture.Trusted<OutputT>
,ListenableFuture<OutputT>
,Future<OutputT>
- Direct Known Subclasses:
CollectionFuture
,CombinedFuture
A future whose value is derived from a collection of input futures.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescription(package private) static enum
Nested classes/interfaces inherited from class com.google.common.util.concurrent.AbstractFuture
AbstractFuture.Trusted<V>, AbstractFuture.TrustedFuture<V>
Nested classes/interfaces inherited from interface java.util.concurrent.Future
Future.State
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final boolean
private final boolean
private ImmutableCollection
<? extends ListenableFuture<? extends InputT>> The input futures.private static final LazyLogger
Fields inherited from class com.google.common.util.concurrent.AbstractFuture
GENERATE_CANCELLATION_CAUSES
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Constructor Summary
ConstructorsConstructorDescriptionAggregateFuture
(ImmutableCollection<? extends ListenableFuture<? extends InputT>> futures, boolean allMustSucceed, boolean collectsValues) -
Method Summary
Modifier and TypeMethodDescriptionprivate static boolean
addCausalChain
(Set<Throwable> seen, Throwable param) Adds the chain to the seen set, and returns whether all the chain was new to us.(package private) final void
addInitialException
(Set<Throwable> seen) Populatesseen
with the exception that was passed tosetException
.protected final void
Callback method that is called exactly once after the future is completed.(package private) abstract void
collectOneValue
(int index, InputT returnValue) IfallMustSucceed
is true, called as each future completes; otherwise, ifcollectsValues
is true, called for each future when all futures complete.private void
collectValueFromNonCancelledFuture
(int index, Future<? extends InputT> future) Collects the result (success or failure) of one input future.private void
decrementCountAndMaybeComplete
(ImmutableCollection<? extends Future<? extends InputT>> futuresIfNeedToCollectAtCompletion) (package private) abstract void
private void
handleException
(Throwable throwable) Fails this future with the given Throwable ifallMustSucceed
is true.(package private) final void
init()
Must be called at the end of each subclass's constructor.private static void
protected final String
Provide a human-readable explanation of why this future has not yet completed.private void
processAllMustSucceedDoneFuture
(int index, ListenableFuture<? extends InputT> future) private void
processCompleted
(ImmutableCollection<? extends Future<? extends InputT>> futuresIfNeedToCollectAtCompletion) (package private) void
Clears fields that are no longer needed after this future has completed -- or at least all its inputs have completed (more precisely, afterhandleAllCompleted()
has been called).Methods inherited from class com.google.common.util.concurrent.AggregateFutureState
clearSeenExceptions, decrementRemainingAndGet, getOrInitSeenExceptions
Methods inherited from class com.google.common.util.concurrent.AbstractFuture.TrustedFuture
addListener, cancel, get, get, isCancelled, isDone
Methods inherited from class com.google.common.util.concurrent.AbstractFuture
interruptTask, maybePropagateCancellationTo, set, setException, setFuture, toString, tryInternalFastPathGetFailure, wasInterrupted
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.concurrent.Future
exceptionNow, resultNow, state
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Field Details
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logger
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futures
The input futures. Afterinit()
, this field is read only byafterDone()
(to propagate cancellation) andAbstractFuture.toString()
. To access the futures' values,AggregateFuture
attaches listeners that hold references to one or more inputs. And in the case ofCombinedFuture
, the user-supplied callback usually has its own references to inputs. -
allMustSucceed
private final boolean allMustSucceed -
collectsValues
private final boolean collectsValues
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Constructor Details
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AggregateFuture
AggregateFuture(ImmutableCollection<? extends ListenableFuture<? extends InputT>> futures, boolean allMustSucceed, boolean collectsValues)
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Method Details
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afterDone
protected final void afterDone()Description copied from class:AbstractFuture
Callback method that is called exactly once after the future is completed.If
AbstractFuture.interruptTask()
is also run during completion,AbstractFuture.afterDone()
runs after it.The default implementation of this method in
AbstractFuture
does nothing. This is intended for very lightweight cleanup work, for example, timing statistics or clearing fields. If your task does anything heavier consider, just using a listener with an executor.- Overrides:
afterDone
in classAbstractFuture<OutputT>
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pendingToString
Description copied from class:AbstractFuture
Provide a human-readable explanation of why this future has not yet completed.- Overrides:
pendingToString
in classAbstractFuture<OutputT>
- Returns:
- null if an explanation cannot be provided (e.g. because the future is done).
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init
final void init()Must be called at the end of each subclass's constructor. This method performs the "real" initialization; we can't put this in the constructor because, in the case where futures are already complete, we would not initialize the subclass before callingcollectValueFromNonCancelledFuture(int, java.util.concurrent.Future<? extends InputT>)
. As this is called after the subclass is constructed, we're guaranteed to have properly initialized the subclass. -
processAllMustSucceedDoneFuture
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handleException
Fails this future with the given Throwable ifallMustSucceed
is true. Also, logs the throwable if it is anError
or ifallMustSucceed
istrue
, the throwable did not cause this future to fail, and it is the first time we've seen that particular Throwable. -
log
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addInitialException
Description copied from class:AggregateFutureState
Populatesseen
with the exception that was passed tosetException
.- Specified by:
addInitialException
in classAggregateFutureState<OutputT>
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collectValueFromNonCancelledFuture
Collects the result (success or failure) of one input future. The input must not have been cancelled. For details on when this is called, seecollectOneValue(int, InputT)
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decrementCountAndMaybeComplete
private void decrementCountAndMaybeComplete(@CheckForNull ImmutableCollection<? extends Future<? extends InputT>> futuresIfNeedToCollectAtCompletion) -
processCompleted
private void processCompleted(@CheckForNull ImmutableCollection<? extends Future<? extends InputT>> futuresIfNeedToCollectAtCompletion) -
releaseResources
Clears fields that are no longer needed after this future has completed -- or at least all its inputs have completed (more precisely, afterhandleAllCompleted()
has been called). Often called multiple times (that is, both when the inputs complete and when the output completes).This is similar to our proposed
afterCommit
method but not quite the same. See the description of CL 265462958. -
collectOneValue
IfallMustSucceed
is true, called as each future completes; otherwise, ifcollectsValues
is true, called for each future when all futures complete. -
handleAllCompleted
abstract void handleAllCompleted() -
addCausalChain
Adds the chain to the seen set, and returns whether all the chain was new to us.
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