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/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow strict-local
* @format
*/
'use strict';
import type {
DeltaResult,
Dependencies,
Graph,
// eslint-disable-next-line no-unused-vars
MixedOutput,
Options,
} from './DeltaBundler/types.flow';
import type EventEmitter from 'events';
const DeltaCalculator = require('./DeltaBundler/DeltaCalculator');
export type {
DeltaResult,
Graph,
Dependencies,
MixedOutput,
Module,
TransformFn,
TransformResult,
TransformResultDependency,
TransformResultWithSource,
} from './DeltaBundler/types.flow';
/**
* `DeltaBundler` uses the `DeltaTransformer` to build bundle deltas. This
* module handles all the transformer instances so it can support multiple
* concurrent clients requesting their own deltas. This is done through the
* `clientId` param (which maps a client to a specific delta transformer).
*/
class DeltaBundler<T = MixedOutput> {
_changeEventSource: EventEmitter;
_deltaCalculators: Map<Graph<T>, DeltaCalculator<T>> = new Map();
constructor(changeEventSource: EventEmitter) {
this._changeEventSource = changeEventSource;
}
end(): void {
this._deltaCalculators.forEach((deltaCalculator: DeltaCalculator<T>) =>
deltaCalculator.end(),
);
this._deltaCalculators = new Map();
}
async getDependencies(
entryPoints: $ReadOnlyArray<string>,
options: Options<T>,
): Promise<Dependencies<T>> {
const deltaCalculator = new DeltaCalculator(
new Set(entryPoints),
this._changeEventSource,
options,
);
await deltaCalculator.getDelta({reset: true, shallow: options.shallow});
const graph = deltaCalculator.getGraph();
deltaCalculator.end();
return graph.dependencies;
}
// Note: the graph returned by this function needs to be ended when finished
// so that we don't leak graphs that are not reachable.
// To get just the dependencies, use getDependencies which will not leak graphs.
async buildGraph(
entryPoints: $ReadOnlyArray<string>,
options: Options<T>,
): Promise<Graph<T>> {
const deltaCalculator = new DeltaCalculator(
new Set(entryPoints),
this._changeEventSource,
options,
);
await deltaCalculator.getDelta({reset: true, shallow: options.shallow});
const graph = deltaCalculator.getGraph();
this._deltaCalculators.set(graph, deltaCalculator);
return graph;
}
async getDelta(
graph: Graph<T>,
{
reset,
shallow,
}: {
reset: boolean,
shallow: boolean,
...
},
): Promise<DeltaResult<T>> {
const deltaCalculator = this._deltaCalculators.get(graph);
if (!deltaCalculator) {
throw new Error('Graph not found');
}
return await deltaCalculator.getDelta({reset, shallow});
}
listen(graph: Graph<T>, callback: () => Promise<void>): () => void {
const deltaCalculator = this._deltaCalculators.get(graph);
if (!deltaCalculator) {
throw new Error('Graph not found');
}
deltaCalculator.on('change', callback);
return () => {
deltaCalculator.removeListener('change', callback);
};
}
endGraph(graph: Graph<T>): void {
const deltaCalculator = this._deltaCalculators.get(graph);
if (!deltaCalculator) {
throw new Error('Graph not found');
}
deltaCalculator.end();
this._deltaCalculators.delete(graph);
}
}
module.exports = DeltaBundler;