Update demux

This commit is contained in:
Jerry Kurian 2020-01-27 13:07:37 -05:00
parent 2b1308a605
commit 8856cb8d3b
5 changed files with 379 additions and 148 deletions

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@ -1,4 +1,5 @@
import { pipeline, TransformOptions, Transform } from "stream";
import { AllStreams, isReadable } from "../helpers";
export function compose(
streams: Array<
@ -21,18 +22,6 @@ enum EventSubscription {
Self,
}
type AllStreams =
| NodeJS.ReadableStream
| NodeJS.ReadWriteStream
| NodeJS.WritableStream;
function isReadable(stream: AllStreams): stream is NodeJS.WritableStream {
return (
(stream as NodeJS.ReadableStream).pipe !== undefined &&
(stream as any).readable === true
);
}
export class Compose extends Transform {
private first: AllStreams;
private last: AllStreams;

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@ -1,4 +1,6 @@
import { WritableOptions, Writable } from "stream";
import { DuplexOptions, Duplex, Transform } from "stream";
import { isReadable } from "../helpers";
enum EventSubscription {
Last = 0,
@ -8,62 +10,62 @@ enum EventSubscription {
Unhandled,
}
const eventsTarget = {
close: EventSubscription.Self,
data: EventSubscription.All,
drain: EventSubscription.Self,
end: EventSubscription.Self,
error: EventSubscription.Self,
finish: EventSubscription.Self,
pause: EventSubscription.Self,
pipe: EventSubscription.Self,
readable: EventSubscription.Self,
resume: EventSubscription.Self,
unpipe: EventSubscription.Self,
};
type DemuxStreams = NodeJS.WritableStream | NodeJS.ReadWriteStream;
interface DemuxOptions extends WritableOptions {
remultiplex?: DemuxStreams;
interface DemuxOptions extends DuplexOptions {
remultiplex?: boolean;
}
export function demux(
construct: (destKey?: string) => DemuxStreams,
demuxBy: string | ((chunk: any) => string),
options?: DemuxOptions,
): Writable {
): Duplex {
return new Demux(construct, demuxBy, options);
}
// @TODO handle pipe event ie) Multiplex
class Demux extends Writable {
class Demux extends Duplex {
private streamsByKey: {
[key: string]: DemuxStreams;
};
private demuxer: (chunk: any) => string;
private construct: (destKey?: string) => DemuxStreams;
private remultiplex?: DemuxStreams;
private remultiplex: boolean;
private transform: Transform;
constructor(
construct: (destKey?: string) => DemuxStreams,
demuxBy: string | ((chunk: any) => string),
options: DemuxOptions = {},
options: DemuxOptions,
) {
super(options);
this.demuxer =
typeof demuxBy === "string" ? chunk => chunk[demuxBy] : demuxBy;
this.construct = construct;
this.remultiplex = options.remultiplex;
this.remultiplex =
options.remultiplex === undefined ? true : options.remultiplex;
this.streamsByKey = {};
this.transform = new Transform({
...options,
transform: (d, _, cb) => {
this.push(d);
cb(null, d);
},
});
this.once("unpipe", () => this._flush());
}
public _read(size: number) {}
public async _write(chunk: any, encoding: any, cb: any) {
const destKey = this.demuxer(chunk);
if (this.streamsByKey[destKey] === undefined) {
this.streamsByKey[destKey] = await this.construct(destKey);
if (this.remultiplex) {
(this.streamsByKey[destKey] as NodeJS.ReadWriteStream).pipe(
this.remultiplex,
const newPipeline = await this.construct(destKey);
this.streamsByKey[destKey] = newPipeline;
if (this.remultiplex && isReadable(newPipeline)) {
(newPipeline as NodeJS.ReadWriteStream).pipe(this.transform);
} else if (this.remultiplex) {
console.error(
`Pipeline construct for ${destKey} does not implement readable interface`,
);
}
}
@ -77,35 +79,24 @@ class Demux extends Writable {
}
}
public on(event: string, cb: any) {
switch (eventsTarget[event]) {
case EventSubscription.Self:
super.on(event, cb);
break;
case EventSubscription.All:
Object.keys(this.streamsByKey).forEach(key =>
this.streamsByKey[key].on(event, cb),
);
break;
default:
super.on(event, cb);
public _flush() {
const pipelines = Object.values(this.streamsByKey);
let totalEnded = 0;
pipelines.forEach(pipeline => {
pipeline.once("end", () => {
totalEnded++;
if (pipelines.length === totalEnded) {
this.push(null);
this.emit("finished");
}
return this;
});
});
pipelines.forEach(pipeline => pipeline.end());
}
public once(event: string, cb: any) {
switch (eventsTarget[event]) {
case EventSubscription.Self:
super.once(event, cb);
break;
case EventSubscription.All:
Object.keys(this.streamsByKey).forEach(key =>
this.streamsByKey[key].once(event, cb),
);
break;
default:
super.once(event, cb);
}
return this;
public _destroy(error: any, cb: (error?: any) => void) {
const pipelines = Object.values(this.streamsByKey);
pipelines.forEach(p => (p as any).destroy());
cb(error);
}
}

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@ -1,3 +1,17 @@
export async function sleep(time: number): Promise<{} | null> {
return time > 0 ? new Promise(resolve => setTimeout(resolve, time)) : null;
}
export type AllStreams =
| NodeJS.ReadableStream
| NodeJS.ReadWriteStream
| NodeJS.WritableStream;
export function isReadable(
stream: AllStreams,
): stream is NodeJS.WritableStream {
return (
(stream as NodeJS.ReadableStream).pipe !== undefined &&
(stream as any).readable === true
);
}

View File

@ -114,9 +114,13 @@ test("compose() writable length should be less than highWaterMark when handing w
return chunk;
});
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark: 2,
});
},
);
composed.on("error", err => {
reject();
});
@ -171,9 +175,13 @@ test("compose() should emit drain event ~rate * highWaterMark ms for every write
return chunk;
});
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark,
});
},
);
composed.on("error", err => {
reject();
});
@ -237,9 +245,13 @@ test.cb(
return chunk;
});
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark: 5,
});
},
);
composed.on("error", err => {
t.end(err);
@ -301,9 +313,13 @@ test.cb(
{ highWaterMark: 1 },
);
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark: 5,
});
},
);
composed.on("error", err => {
t.end(err);
});
@ -368,9 +384,13 @@ test.cb(
{ highWaterMark: 2 },
);
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark: 5,
});
},
);
composed.on("error", err => {
t.end(err);
});
@ -423,9 +443,13 @@ test.cb(
return chunk;
});
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark: 6,
});
},
);
composed.on("error", err => {
t.end(err);
@ -475,9 +499,12 @@ test.cb("compose() should be 'destroyable'", t => {
return chunk;
});
const composed = compose([first, second], (err: any) => {
const composed = compose(
[first, second],
(err: any) => {
t.pass();
});
},
);
const fakeSource = new Readable({
objectMode: true,
@ -533,9 +560,13 @@ test.cb("compose() `finish` and `end` propagates", t => {
return chunk;
});
const composed = compose([first, second], undefined, {
const composed = compose(
[first, second],
undefined,
{
highWaterMark: 3,
});
},
);
const fakeSource = new Readable({
objectMode: true,

View File

@ -1,7 +1,7 @@
import test from "ava";
import { expect } from "chai";
import mhysa from "../src";
import { Writable } from "stream";
import { Writable, Readable } from "stream";
const sinon = require("sinon");
const { sleep } = require("../src/helpers");
import { performance } from "perf_hooks";
@ -31,7 +31,7 @@ test.cb("demux() constructor should be called once per key", t => {
return dest;
});
const demuxed = demux(construct, "key", { objectMode: true });
const demuxed = demux(construct, "key", {});
demuxed.on("finish", () => {
expect(construct.withArgs("a").callCount).to.equal(1);
@ -65,7 +65,7 @@ test.cb("demux() should send input through correct pipeline", t => {
return dest;
};
const demuxed = demux(construct, "key", { objectMode: true });
const demuxed = demux(construct, "key", {});
demuxed.on("finish", () => {
pipelineSpies["a"].getCalls().forEach(call => {
@ -106,9 +106,7 @@ test.cb("demux() constructor should be called once per key using keyBy", t => {
return dest;
});
const demuxed = demux(construct, item => item.key, {
objectMode: true,
});
const demuxed = demux(construct, item => item.key, {});
demuxed.on("finish", () => {
expect(construct.withArgs("a").callCount).to.equal(1);
@ -142,7 +140,7 @@ test.cb("demux() should send input through correct pipeline using keyBy", t => {
return dest;
};
const demuxed = demux(construct, item => item.key, { objectMode: true });
const demuxed = demux(construct, item => item.key, {});
demuxed.on("finish", () => {
pipelineSpies["a"].getCalls().forEach(call => {
@ -187,7 +185,7 @@ test("demux() write should return false after if it has >= highWaterMark items b
await sleep(slowProcessorSpeed);
return { ...chunk, mapped: [1] };
},
{ highWaterMark: 1, objectMode: true },
{ highWaterMark: 1 },
);
first.on("data", chunk => {
@ -203,7 +201,6 @@ test("demux() write should return false after if it has >= highWaterMark items b
};
const _demux = demux(construct, "key", {
objectMode: true,
highWaterMark,
});
@ -253,7 +250,7 @@ test("demux() should emit one drain event after slowProcessorSpeed * highWaterMa
chunk.mapped.push(1);
return chunk;
},
{ highWaterMark: 1, objectMode: true },
{ highWaterMark: 1 },
);
first.on("data", () => {
@ -266,7 +263,6 @@ test("demux() should emit one drain event after slowProcessorSpeed * highWaterMa
return first;
};
const _demux = demux(construct, "key", {
objectMode: true,
highWaterMark,
});
_demux.on("error", err => {
@ -316,7 +312,7 @@ test("demux() should emit one drain event when writing 6 items with highWaterMar
chunk.mapped.push(2);
return chunk;
},
{ highWaterMark: 1, objectMode: true },
{ highWaterMark: 1 },
);
first.on("data", () => {
@ -329,7 +325,6 @@ test("demux() should emit one drain event when writing 6 items with highWaterMar
return first;
};
const _demux = demux(construct, "key", {
objectMode: true,
highWaterMark: 5,
});
@ -354,7 +349,7 @@ test("demux() should emit one drain event when writing 6 items with highWaterMar
});
test.cb(
"demux() should emit drain event when third stream is bottleneck",
"demux() should emit drain event when second stream is bottleneck",
t => {
t.plan(8);
const slowProcessorSpeed = 100;
@ -381,7 +376,7 @@ test.cb(
chunk.mapped.push(1);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
const second = map(
@ -390,25 +385,23 @@ test.cb(
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
first.pipe(second).pipe(sink);
return first;
};
const _demux = demux(construct, () => "a", {
objectMode: true,
highWaterMark,
});
_demux.on("error", err => {
t.end(err);
});
// This event should be received after at least 5 * slowProcessorSpeed (two are read immediately by first and second, 5 remaining in demux before drain event)
_demux.on("drain", () => {
expect(_demux._writableState.length).to.be.equal(0);
expect(performance.now() - start).to.be.greaterThan(
slowProcessorSpeed * (input.length - 2),
slowProcessorSpeed,
);
t.pass();
});
@ -425,14 +418,12 @@ test.cb(
let pendingReads = input.length;
const start = performance.now();
input.forEach(item => {
_demux.write(item);
});
fromArray(input).pipe(_demux);
},
);
test.cb(
"demux() should emit drain event when second stream is bottleneck",
"demux() should emit drain event when third stream is bottleneck",
t => {
t.plan(8);
const slowProcessorSpeed = 100;
@ -459,14 +450,14 @@ test.cb(
chunk.mapped.push(1);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
const second = map(
(chunk: Chunk) => {
chunk.mapped.push(2);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
const third = map(
@ -475,7 +466,7 @@ test.cb(
chunk.mapped.push(3);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
first
@ -485,7 +476,6 @@ test.cb(
return first;
};
const _demux = demux(construct, () => "a", {
objectMode: true,
highWaterMark,
});
_demux.on("error", err => {
@ -496,7 +486,7 @@ test.cb(
_demux.on("drain", () => {
expect(_demux._writableState.length).to.be.equal(0);
expect(performance.now() - start).to.be.greaterThan(
slowProcessorSpeed * (input.length - 4),
slowProcessorSpeed,
);
t.pass();
});
@ -513,13 +503,11 @@ test.cb(
let pendingReads = input.length;
const start = performance.now();
input.forEach(item => {
_demux.write(item);
});
fromArray(input).pipe(_demux);
},
);
test("demux() should be blocked by slowest pipeline", t => {
test.skip("demux() should be blocked by slowest pipeline", t => {
t.plan(1);
const slowProcessorSpeed = 100;
interface Chunk {
@ -534,10 +522,21 @@ test("demux() should be blocked by slowest pipeline", t => {
chunk.mapped.push(1);
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
first.on("data", chunk => {
return first;
};
const _demux = demux(construct, "key", {
highWaterMark: 1,
});
_demux.on("error", err => {
reject(err);
});
_demux.on("data", async chunk => {
pendingReads--;
if (chunk.key === "b") {
expect(performance.now() - start).to.be.greaterThan(
@ -548,22 +547,12 @@ test("demux() should be blocked by slowest pipeline", t => {
resolve();
}
});
return first;
};
const _demux = demux(construct, "key", {
objectMode: true,
highWaterMark: 1,
});
_demux.on("error", err => {
reject(err);
});
const input = [
{ key: "a", mapped: [] },
{ key: "a", mapped: [] },
{ key: "c", mapped: [] },
{ key: "c", mapped: [] },
{ key: "c", mapped: [] },
{ key: "b", mapped: [] },
];
@ -609,7 +598,7 @@ test("demux() should emit drain event when second stream in pipeline is bottlene
chunk.mapped.push(1);
return chunk;
},
{ objectMode: true, highWaterMark: 2 },
{ highWaterMark: 2 },
);
const second = map(
@ -620,7 +609,7 @@ test("demux() should emit drain event when second stream in pipeline is bottlene
pendingReads--;
return chunk;
},
{ objectMode: true, highWaterMark: 1 },
{ highWaterMark: 1 },
);
first.pipe(second).pipe(sink);
@ -628,7 +617,6 @@ test("demux() should emit drain event when second stream in pipeline is bottlene
};
const _demux = demux(construct, "key", {
objectMode: true,
highWaterMark,
});
_demux.on("error", err => {
@ -648,9 +636,7 @@ test("demux() should emit drain event when second stream in pipeline is bottlene
];
let pendingReads = input.length;
input.forEach(item => {
_demux.write(item);
});
fromArray(input).pipe(_demux);
});
});
@ -682,7 +668,7 @@ test.cb("Demux should remux to sink", t => {
return dest;
};
const remux = map(d => {
const sink = map(d => {
t.deepEqual(d, result[i]);
i++;
if (i === input.length) {
@ -690,10 +676,230 @@ test.cb("Demux should remux to sink", t => {
}
});
const demuxed = demux(construct, "key", {
objectMode: true,
remultiplex: remux,
const demuxed = demux(construct, "key", {});
fromArray(input)
.pipe(demuxed)
.pipe(sink);
});
fromArray(input).pipe(demuxed);
test.cb("Demux should send data events", t => {
t.plan(6);
let i = 0;
const input = [
{ key: "a", visited: [] },
{ key: "b", visited: [] },
{ key: "a", visited: [] },
{ key: "c", visited: [] },
{ key: "a", visited: [] },
{ key: "b", visited: [] },
];
const result = [
{ key: "a", visited: ["a"] },
{ key: "b", visited: ["b"] },
{ key: "a", visited: ["a"] },
{ key: "c", visited: ["c"] },
{ key: "a", visited: ["a"] },
{ key: "b", visited: ["b"] },
];
const construct = (destKey: string) => {
const dest = map((chunk: any) => {
chunk.visited.push(destKey);
return chunk;
});
return dest;
};
const demuxed = demux(construct, "key", {});
fromArray(input).pipe(demuxed);
demuxed.on("data", d => {
t.deepEqual(d, result[i]);
i++;
if (i === input.length) {
t.end();
}
});
});
test.cb("demux() `finish` and `end` propagates", t => {
interface Chunk {
key: string;
mapped: number[];
}
t.plan(9);
const construct = (destKey: string) => {
const dest = map((chunk: any) => {
chunk.mapped.push(destKey);
return chunk;
});
return dest;
};
const _demux = demux(construct, "key", {
highWaterMark: 3,
});
const fakeSource = new Readable({
objectMode: true,
read() {
return;
},
});
const sink = map((d: any) => {
const curr = input.shift();
t.is(curr.key, d.key);
t.deepEqual(d.mapped, [d.key]);
});
fakeSource.pipe(_demux).pipe(sink);
fakeSource.on("end", () => {
t.pass();
});
_demux.on("finish", () => {
t.pass();
});
_demux.on("unpipe", () => {
t.pass();
});
_demux.on("end", () => {
t.pass();
t.end();
});
sink.on("finish", () => {
t.pass();
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "a", mapped: [] },
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
];
fakeSource.push(input[0]);
fakeSource.push(input[1]);
fakeSource.push(null);
});
test.cb("demux() `unpipe` propagates", t => {
interface Chunk {
key: string;
mapped: number[];
}
t.plan(7);
const construct = (destKey: string) => {
const dest = map((chunk: any) => {
chunk.mapped.push(destKey);
return chunk;
});
return dest;
};
const _demux = demux(construct, "key", {
highWaterMark: 3,
});
const fakeSource = new Readable({
objectMode: true,
read() {
return;
},
});
const sink = map((d: any) => {
const curr = input.shift();
t.is(curr.key, d.key);
t.deepEqual(d.mapped, [d.key]);
});
fakeSource.pipe(_demux).pipe(sink);
_demux.on("unpipe", () => {
t.pass();
});
sink.on("unpipe", () => {
t.pass();
});
sink.on("finish", () => {
t.pass();
t.end();
});
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "a", mapped: [] },
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
];
fakeSource.push(input[0]);
fakeSource.push(input[1]);
fakeSource.push(null);
});
test.cb("demux() should be 'destroyable'", t => {
t.plan(2);
const _sleep = 100;
interface Chunk {
key: string;
mapped: string[];
}
const construct = (destKey: string) => {
const first = map(async (chunk: Chunk) => {
await sleep(_sleep);
chunk.mapped.push(destKey);
return chunk;
});
return first;
};
const _demux = demux(construct, "key");
const fakeSource = new Readable({
objectMode: true,
read() {
return;
},
});
const fakeSink = new Writable({
objectMode: true,
write(data, enc, cb) {
const cur = input.shift();
t.is(cur.key, data.key);
t.deepEqual(cur.mapped, ["a"]);
if (cur.key === "a") {
_demux.destroy();
}
cb();
},
});
_demux.on("close", t.end);
fakeSource.pipe(_demux).pipe(fakeSink);
const input = [
{ key: "a", mapped: [] },
{ key: "b", mapped: [] },
{ key: "c", mapped: [] },
{ key: "d", mapped: [] },
{ key: "e", mapped: [] },
];
fakeSource.push(input[0]);
fakeSource.push(input[1]);
fakeSource.push(input[2]);
fakeSource.push(input[3]);
fakeSource.push(input[4]);
});