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Operation class

This API is provided as a beta preview for developers and may change based on feedback that we receive. Do not use this API in a production environment.

The Operation class is a node in the dependency graph of work that needs to be scheduled by the OperationExecutionManager. Each Operation has a runner member of type IOperationRunner, whose implementation manages the actual process of running a single operation.

The graph of Operation instances will be cloned into a separate execution graph after processing.

Signature:

export declare class Operation<TMetadata extends {} = {}, TGroupMetadata extends {} = {}> implements IOperationStates 

Implements: IOperationStates

Constructors

Constructor	Modifiers	Description
(constructor)(options)		(BETA) Constructs a new instance of the Operation class

Properties

Property	Modifiers	Type	Description
consumers	readonly	Set<Operation<TMetadata, TGroupMetadata>>	(BETA) A set of all operations that wait for this operation.
criticalPathLength		number | undefined	(BETA) This number represents how far away this Operation is from the furthest "root" operation (i.e. an operation with no consumers). This helps us to calculate the critical path (i.e. the longest chain of projects which must be executed in order, thereby limiting execution speed of the entire operation tree. This number is calculated via a memoized depth-first search, and when choosing the next operation to execute, the operation with the highest criticalPathLength is chosen. Example: (0) A \ (1) B C (0) (applications) \ /|\ \ / | \ (2) D | X (1) (utilities) | / \ |/ \ (2) Y Z (2) (other utilities) All roots (A & C) have a criticalPathLength of 0. B has a score of 1, since A depends on it. D has a score of 2, since we look at the longest chain (e.g D->B->A is longer than D->C) X has a score of 1, since the only package which depends on it is A Z has a score of 2, since only X depends on it, and X has a score of 1 Y has a score of 2, since the chain Y->X->C is longer than Y->C The algorithm is implemented in AsyncOperationQueue.ts as calculateCriticalPathLength()
dependencies	readonly	Set<Operation<TMetadata, TGroupMetadata>>	(BETA) A set of all dependencies which must be executed before this operation is complete.
group	readonly	OperationGroupRecord<TGroupMetadata> | undefined	(BETA) If specified, the name of a grouping to which this Operation belongs, for logging start and end times.
lastState		IOperationState | undefined	(BETA) The state of this operation the previous time a manager was invoked.
metadata	readonly	TMetadata	(BETA)
name	readonly	string	(BETA) The name of this operation, for logging.
runner		IOperationRunner | undefined	(BETA) When the scheduler is ready to process this Operation, the runner implements the actual work of running the operation.
state		IOperationState | undefined	(BETA) The current state of this operation
weight		number	(BETA) The weight for this operation. This scalar is the contribution of this operation to the criticalPathLength calculation above. Modify to indicate the following: - weight === 1: indicates that this operation has an average duration - weight &gt; 1: indicates that this operation takes longer than average and so the scheduler should try to favor starting it over other, shorter operations. An example might be an operation that bundles an entire application and runs whole-program optimization. - weight &lt; 1: indicates that this operation takes less time than average and so the scheduler should favor other, longer operations over it. An example might be an operation to unpack a cached output, or an operation using NullOperationRunner, which might use a value of 0.

Methods

Method	Modifiers	Description
addDependency(dependency)		(BETA)
deleteDependency(dependency)		(BETA)
reset()		(BETA)