rdesign/frontend/node_modules/signal-polyfill/dist/graph.d.ts

197 lines
7.6 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
type Version = number & {
__brand: 'Version';
};
/**
* Symbol used to tell `Signal`s apart from other functions.
*
* This can be used to auto-unwrap signals in various cases, or to auto-wrap non-signal values.
*/
export declare const SIGNAL: unique symbol;
export declare function setActiveConsumer(consumer: ReactiveNode | null): ReactiveNode | null;
export declare function getActiveConsumer(): ReactiveNode | null;
export declare function isInNotificationPhase(): boolean;
export interface Reactive {
[SIGNAL]: ReactiveNode;
}
export declare function isReactive(value: unknown): value is Reactive;
export declare const REACTIVE_NODE: ReactiveNode;
/**
* A producer and/or consumer which participates in the reactive graph.
*
* Producer `ReactiveNode`s which are accessed when a consumer `ReactiveNode` is the
* `activeConsumer` are tracked as dependencies of that consumer.
*
* Certain consumers are also tracked as "live" consumers and create edges in the other direction,
* from producer to consumer. These edges are used to propagate change notifications when a
* producer's value is updated.
*
* A `ReactiveNode` may be both a producer and consumer.
*/
export interface ReactiveNode {
/**
* Version of the value that this node produces.
*
* This is incremented whenever a new value is produced by this node which is not equal to the
* previous value (by whatever definition of equality is in use).
*/
version: Version;
/**
* Epoch at which this node is verified to be clean.
*
* This allows skipping of some polling operations in the case where no signals have been set
* since this node was last read.
*/
lastCleanEpoch: Version;
/**
* Whether this node (in its consumer capacity) is dirty.
*
* Only live consumers become dirty, when receiving a change notification from a dependency
* producer.
*/
dirty: boolean;
/**
* Producers which are dependencies of this consumer.
*
* Uses the same indices as the `producerLastReadVersion` and `producerIndexOfThis` arrays.
*/
producerNode: ReactiveNode[] | undefined;
/**
* `Version` of the value last read by a given producer.
*
* Uses the same indices as the `producerNode` and `producerIndexOfThis` arrays.
*/
producerLastReadVersion: Version[] | undefined;
/**
* Index of `this` (consumer) in each producer's `liveConsumers` array.
*
* This value is only meaningful if this node is live (`liveConsumers.length > 0`). Otherwise
* these indices are stale.
*
* Uses the same indices as the `producerNode` and `producerLastReadVersion` arrays.
*/
producerIndexOfThis: number[] | undefined;
/**
* Index into the producer arrays that the next dependency of this node as a consumer will use.
*
* This index is zeroed before this node as a consumer begins executing. When a producer is read,
* it gets inserted into the producers arrays at this index. There may be an existing dependency
* in this location which may or may not match the incoming producer, depending on whether the
* same producers were read in the same order as the last computation.
*/
nextProducerIndex: number;
/**
* Array of consumers of this producer that are "live" (they require push notifications).
*
* `liveConsumerNode.length` is effectively our reference count for this node.
*/
liveConsumerNode: ReactiveNode[] | undefined;
/**
* Index of `this` (producer) in each consumer's `producerNode` array.
*
* Uses the same indices as the `liveConsumerNode` array.
*/
liveConsumerIndexOfThis: number[] | undefined;
/**
* Whether writes to signals are allowed when this consumer is the `activeConsumer`.
*
* This is used to enforce guardrails such as preventing writes to writable signals in the
* computation function of computed signals, which is supposed to be pure.
*/
consumerAllowSignalWrites: boolean;
readonly consumerIsAlwaysLive: boolean;
/**
* Tracks whether producers need to recompute their value independently of the reactive graph (for
* example, if no initial value has been computed).
*/
producerMustRecompute(node: unknown): boolean;
producerRecomputeValue(node: unknown): void;
consumerMarkedDirty(this: unknown): void;
/**
* Called when a signal is read within this consumer.
*/
consumerOnSignalRead(node: unknown): void;
/**
* Called when the signal becomes "live"
*/
watched?(): void;
/**
* Called when the signal stops being "live"
*/
unwatched?(): void;
/**
* Optional extra data for embedder of this signal library.
* Sent to various callbacks as the this value.
*/
wrapper?: any;
}
interface ConsumerNode extends ReactiveNode {
producerNode: NonNullable<ReactiveNode['producerNode']>;
producerIndexOfThis: NonNullable<ReactiveNode['producerIndexOfThis']>;
producerLastReadVersion: NonNullable<ReactiveNode['producerLastReadVersion']>;
}
interface ProducerNode extends ReactiveNode {
liveConsumerNode: NonNullable<ReactiveNode['liveConsumerNode']>;
liveConsumerIndexOfThis: NonNullable<ReactiveNode['liveConsumerIndexOfThis']>;
}
/**
* Called by implementations when a producer's signal is read.
*/
export declare function producerAccessed(node: ReactiveNode): void;
/**
* Increment the global epoch counter.
*
* Called by source producers (that is, not computeds) whenever their values change.
*/
export declare function producerIncrementEpoch(): void;
/**
* Ensure this producer's `version` is up-to-date.
*/
export declare function producerUpdateValueVersion(node: ReactiveNode): void;
/**
* Propagate a dirty notification to live consumers of this producer.
*/
export declare function producerNotifyConsumers(node: ReactiveNode): void;
/**
* Whether this `ReactiveNode` in its producer capacity is currently allowed to initiate updates,
* based on the current consumer context.
*/
export declare function producerUpdatesAllowed(): boolean;
export declare function consumerMarkDirty(node: ReactiveNode): void;
/**
* Prepare this consumer to run a computation in its reactive context.
*
* Must be called by subclasses which represent reactive computations, before those computations
* begin.
*/
export declare function consumerBeforeComputation(node: ReactiveNode | null): ReactiveNode | null;
/**
* Finalize this consumer's state after a reactive computation has run.
*
* Must be called by subclasses which represent reactive computations, after those computations
* have finished.
*/
export declare function consumerAfterComputation(node: ReactiveNode | null, prevConsumer: ReactiveNode | null): void;
/**
* Determine whether this consumer has any dependencies which have changed since the last time
* they were read.
*/
export declare function consumerPollProducersForChange(node: ReactiveNode): boolean;
/**
* Disconnect this consumer from the graph.
*/
export declare function consumerDestroy(node: ReactiveNode): void;
/**
* Remove the live consumer at `idx`.
*/
export declare function producerRemoveLiveConsumerAtIndex(node: ReactiveNode, idx: number): void;
export declare function assertConsumerNode(node: ReactiveNode): asserts node is ConsumerNode;
export declare function assertProducerNode(node: ReactiveNode): asserts node is ProducerNode;
export {};
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