com.facebook.buck.core.graph.transformation.composition

Interface ComposedComputation<BaseKey extends ComputeKey<?>,Result2 extends ComputeResult>

Type Parameters:

BaseKey - the key type contained in the composed key of the base computation

Result2 - the result type contained in the composed result of this computation

All Superinterfaces:

GraphComputation<ComposedKey<BaseKey,Result2>,ComposedResult<ComputeKey<Result2>,Result2>>

All Known Implementing Classes:

LeftComposingComputation, RightComposingComputation

public interface ComposedComputation<BaseKey extends ComputeKey<?>,Result2 extends ComputeResult>
extends GraphComputation<ComposedKey<BaseKey,Result2>,ComposedResult<ComputeKey<Result2>,Result2>>

A GraphComputation that represents the Composition of a ComposedComputation that we can the base computation, a Composer, and a Transformer.

This computation has a ComposedKey of the primary computation key and the result of the Transformer. After the base computation completes, the Composer will be invoked for each individual result in the ComposedResult of the base computation, returning a set of dependencies necessary for the transform step. Then Transformer is invoked with the dependencies.

The computation is identified by the base computation it begins at and the target result type class, which means that no two ComposedComputations that begins and ends at the same computations can be registered with the graph engine, regardless of what intermediate paths they may differ at.

Method Summary

Modifier and Type	Method and Description
GraphComputationStage<ComposedKey<BaseKey,Result2>,ComposedResult<ComputeKey<Result2>,Result2>>	asStage()
com.google.common.collect.ImmutableSet<? extends ComputeKey<? extends ComputeResult>>	discoverDeps(ComposedKey<BaseKey,Result2> key, ComputationEnvironment env) Compute dependent keys required to compute given key, and a set of dependencies as listed by GraphComputation.discoverPreliminaryDeps(ComputeKey).
com.google.common.collect.ImmutableSet<? extends ComputeKey<? extends ComputeResult>>	discoverPreliminaryDeps(ComposedKey<BaseKey,Result2> key) Compute dependent keys required to compute given the current key.
ComposedComputationIdentifier<Result2>	getIdentifier()
ComposedResult<ComputeKey<Result2>,Result2>	transform(ComposedKey<BaseKey,Result2> key, ComputationEnvironment env) Perform a transformation identified by key Key into a final type Result.

Method Detail

getIdentifier

ComposedComputationIdentifier<Result2> getIdentifier()

Specified by:

getIdentifier in interface GraphComputation<ComposedKey<BaseKey extends ComputeKey<?>,Result2 extends ComputeResult>,ComposedResult<ComputeKey<Result2 extends ComputeResult>,Result2 extends ComputeResult>>

Returns:

the identifier of the key for this transformation. This should match ComputeKey.getIdentifier()

transform

ComposedResult<ComputeKey<Result2>,Result2> transform(ComposedKey<BaseKey,Result2> key,
                                                      ComputationEnvironment env)
                                               throws Exception

Description copied from interface: GraphComputation

Perform a transformation identified by key Key into a final type Result. This transformation should be performed synchronously.

Specified by:

transform in interface GraphComputation<ComposedKey<BaseKey extends ComputeKey<?>,Result2 extends ComputeResult>,ComposedResult<ComputeKey<Result2 extends ComputeResult>,Result2 extends ComputeResult>>

Parameters:

key - The Key of the requested result

env - The execution environment containing results of keys from GraphComputation.discoverDeps(ComputeKey, ComputationEnvironment) and GraphComputation.discoverPreliminaryDeps(ComputeKey)

Returns:

The result of the transformation

Throws:

Exception

discoverDeps

com.google.common.collect.ImmutableSet<? extends ComputeKey<? extends ComputeResult>> discoverDeps(ComposedKey<BaseKey,Result2> key,
                                                                                                   ComputationEnvironment env)
                                                                                            throws Exception

Description copied from interface: GraphComputation

Compute dependent keys required to compute given key, and a set of dependencies as listed by GraphComputation.discoverPreliminaryDeps(ComputeKey). The results of those computations will be available in GraphComputation.transform(ComputeKey, ComputationEnvironment) as a part of ComputationEnvironment

Specified by:

discoverDeps in interface GraphComputation<ComposedKey<BaseKey extends ComputeKey<?>,Result2 extends ComputeResult>,ComposedResult<ComputeKey<Result2 extends ComputeResult>,Result2 extends ComputeResult>>

Parameters:

key - the current key to transform

env - The execution environment containing results of keys from GraphComputation.discoverPreliminaryDeps(ComputeKey)

Returns:

a set of keys that the transformation of the current key depends on

Throws:

Exception

discoverPreliminaryDeps

com.google.common.collect.ImmutableSet<? extends ComputeKey<? extends ComputeResult>> discoverPreliminaryDeps(ComposedKey<BaseKey,Result2> key)

Description copied from interface: GraphComputation

Compute dependent keys required to compute given the current key. The results of those computations will be available in GraphComputation.discoverDeps(ComputeKey, ComputationEnvironment) as a part of ComputationEnvironment, and GraphComputation.transform(ComputeKey, ComputationEnvironment)

Specified by:

discoverPreliminaryDeps in interface GraphComputation<ComposedKey<BaseKey extends ComputeKey<?>,Result2 extends ComputeResult>,ComposedResult<ComputeKey<Result2 extends ComputeResult>,Result2 extends ComputeResult>>

Parameters:

key - the current key to transform

Returns:

a set of keys that the GraphComputation.discoverDeps(ComputeKey, ComputationEnvironment) and GraphComputation.transform(ComputeKey, ComputationEnvironment) of the current key depends on

asStage

GraphComputationStage<ComposedKey<BaseKey,Result2>,ComposedResult<ComputeKey<Result2>,Result2>> asStage()

Returns:

a non caching GraphComputationStage for registering this computation with the GraphTransformationEngine