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https://github.com/vercel-labs/scriptc.git
synced 2026-11-02 07:43:42 +08:00
Chris Tate
447f56e5c3
- EventEmitter.defaultMaxListeners on the untyped constructor is Node's
accessor over the default the typed EventEmitter reads: assignments
validate as validateNumber(arg, 'defaultMaxListeners', 0) does, and
getMaxListeners() of emitters without their own limit answers the new
value.
- dyn.builtinInstanceOf and dyn.functionInstanceOf link the
constructor-function unit and the units it calls (dyn-invoke, inspect,
symbol, emitter), so a program whose only use is `this instanceof F`
links.
- The legacy pipe's cleanup runs once: when the destination emits
'close' from end(), the cleanup still queued on the source's 'end'
finds the listeners removed and emit('end') answers true.
54 lines
1.5 KiB
JavaScript
54 lines
1.5 KiB
JavaScript
// EventEmitter.defaultMaxListeners read and written through the untyped
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// EventEmitter constructor (Node's accessor and its validation), and a
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// legacy pipe whose destination emits 'close' synchronously from end().
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"use strict";
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const util = require("util");
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const EventEmitter = require("events");
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const Stream = require("stream");
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function Bus() {
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EventEmitter.call(this);
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}
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util.inherits(Bus, EventEmitter);
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console.log(EventEmitter.defaultMaxListeners);
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console.log(new Bus().getMaxListeners());
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EventEmitter.defaultMaxListeners = 3;
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console.log(EventEmitter.defaultMaxListeners, new Bus().getMaxListeners());
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for (const value of [-1, "4", Number.NaN]) {
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try {
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EventEmitter.defaultMaxListeners = value;
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} catch (error) {
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console.log(error.name, error.code, error.message);
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}
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}
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console.log(EventEmitter.defaultMaxListeners);
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EventEmitter.defaultMaxListeners = 10;
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function Source() {
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Stream.call(this);
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this.readable = true;
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}
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util.inherits(Source, Stream);
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function Sink() {
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Stream.call(this);
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this.writable = true;
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}
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util.inherits(Sink, Stream);
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Sink.prototype.write = function (chunk) {
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console.log("write", chunk);
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return true;
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};
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Sink.prototype.end = function () {
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console.log("sink end");
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this.emit("close");
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};
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const source = new Source();
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const sink = new Sink();
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source.pipe(sink);
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source.emit("data", "a");
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console.log("emit end", source.emit("end"));
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console.log("listeners", source.listenerCount("end"), source.listenerCount("data"), sink.listenerCount("close"));
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