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1e0f3315c7
Emit 'readable' always in the next tick, resulting in a single call to _read() per microtick. This removes the need for the user to implement buffering if they wanted to call this.push() multiple times in an asynchronous fashion, as this.push() triggers this._read() call. PR-URL: https://github.com/nodejs/node/pull/17979 Fixes: https://github.com/nodejs/node/issues/3203 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
67 lines
1.7 KiB
JavaScript
67 lines
1.7 KiB
JavaScript
'use strict';
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const common = require('../common');
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const assert = require('assert');
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const Readable = require('stream').Readable;
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const readable = new Readable({
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read(size) {}
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});
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const state = readable._readableState;
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// Starting off with false initially.
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assert.strictEqual(state.reading, false);
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assert.strictEqual(state.readingMore, false);
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readable.on('data', common.mustCall((data) => {
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// while in a flowing state, should try to read more.
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if (readable.readableFlowing)
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assert.strictEqual(state.readingMore, true);
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// reading as long as we've not ended
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assert.strictEqual(state.reading, !state.ended);
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}, 2));
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function onStreamEnd() {
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// End of stream; state.reading is false
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// And so should be readingMore.
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assert.strictEqual(state.readingMore, false);
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assert.strictEqual(state.reading, false);
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}
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readable.on('readable', common.mustCall(() => {
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// 'readable' always gets called before 'end'
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// since 'end' hasn't been emitted, more data could be incoming
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assert.strictEqual(state.readingMore, true);
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// if the stream has ended, we shouldn't be reading
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assert.strictEqual(state.ended, !state.reading);
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const data = readable.read();
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if (data === null) // reached end of stream
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process.nextTick(common.mustCall(onStreamEnd, 1));
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}, 2));
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readable.on('end', common.mustCall(onStreamEnd));
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readable.push('pushed');
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// stop emitting 'data' events
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readable.pause();
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// read() should only be called while operating in paused mode
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readable.read(6);
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// reading
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assert.strictEqual(state.reading, true);
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assert.strictEqual(state.readingMore, true);
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// resume emitting 'data' events
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readable.resume();
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// add chunk to front
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readable.unshift('unshifted');
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// end
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readable.push(null);
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