57 lines
2.1 KiB
TypeScript
57 lines
2.1 KiB
TypeScript
/**
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* Copyright (c) Microsoft Corporation.
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*
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* Licensed under the Apache License, Version 2.0 (the 'License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import type * as channels from '@protocol/channels';
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import { Dispatcher } from './dispatcher';
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import type * as stream from 'stream';
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import { ManualPromise, createGuid } from '../../utils';
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import type { ArtifactDispatcher } from './artifactDispatcher';
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export class StreamDispatcher extends Dispatcher<{ guid: string, stream: stream.Readable }, channels.StreamChannel, ArtifactDispatcher> implements channels.StreamChannel {
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_type_Stream = true;
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private _ended: boolean = false;
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constructor(scope: ArtifactDispatcher, stream: stream.Readable) {
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super(scope, { guid: 'stream@' + createGuid(), stream }, 'Stream', {});
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// In Node v12.9.0+ we can use readableEnded.
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stream.once('end', () => this._ended = true);
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stream.once('error', () => this._ended = true);
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}
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async read(params: channels.StreamReadParams): Promise<channels.StreamReadResult> {
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const stream = this._object.stream;
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if (this._ended)
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return { binary: Buffer.from('') };
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if (!stream.readableLength) {
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const readyPromise = new ManualPromise<void>();
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const done = () => readyPromise.resolve();
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stream.on('readable', done);
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stream.on('end', done);
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stream.on('error', done);
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await readyPromise;
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stream.off('readable', done);
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stream.off('end', done);
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stream.off('error', done);
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}
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const buffer = stream.read(Math.min(stream.readableLength, params.size || stream.readableLength));
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return { binary: buffer || Buffer.from('') };
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}
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async close() {
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this._object.stream.destroy();
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}
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}
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