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@DullReferenceException

DullReferenceException/benchmark.js

Created November 20, 2019 18:58
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Streams versus async iterables benchmark
Raw
benchmark.js
const { Readable, Transform } = require('stream');
const { createWriteStream } = require('fs');
const { once } = require('events');
const path = require('path');
const tmp = require('os').tmpdir();
function* iterateThroughNumbers(count = 1000000) {
for (let i = 0; i < count; i++) {
yield i;
}
}
const sourceStream = () => Readable.from(iterateThroughNumbers());
const transformStream = () => new Transform({
writableObjectMode: true,
readableObjectMode: false,
transform(item, encoding, cb) {
return cb(null, transform(item));
}
});
const transform = item => (item * 2).toString();
const writeStream = (name = 'out') => createWriteStream(path.join(tmp, './out'));
async function toWritableWithTransformStream() {
const pipeline = sourceStream()
.pipe(transformStream())
.pipe(writeStream('one'));
await once(pipeline, 'close');
}
async function toWritableWithIteration() {
const writable = writeStream('two');
for await (const item of sourceStream()) {
const transformed = transform(item);
if (!writable.write(transformed)) {
await once(writable, 'drain');
}
}
writable.end();
await once(writable, 'close');
}
async function toArrayWithTransformStream() {
const buffer = [];
const pipeline = sourceStream()
.pipe(transformStream());
pipeline.on('data', item => buffer.push(item));
await once(pipeline, 'end');
return buffer;
}
async function toArrayWithIteration() {
const buffer = [];
for await (const item of sourceStream()) {
const transformed = transform(item);
buffer.push(transformed);
}
return buffer;
}
async function noStreamtoArray() {
const buffer = [];
for await (const item of iterateThroughNumbers()) {
const transformed = transform(item);
buffer.push(transformed);
}
return buffer;
}
(async function() {
console.time('stream -> TransformStream -> Writable');
await toWritableWithTransformStream();
console.timeEnd('stream -> TransformStream -> Writable');
console.time('stream -> iteration -> Writable');
await toWritableWithIteration();
console.timeEnd('stream -> iteration -> Writable');
console.time('stream -> TransformStream -> read into Array');
await toArrayWithTransformStream();
console.timeEnd('stream -> TransformStream -> read into Array');
console.time('stream -> iteration -> push into Array');
await toArrayWithIteration();
console.timeEnd('stream -> iteration -> push into Array');
console.time('iterable -> iteration -> push into Array');
await noStreamtoArray();
console.timeEnd('iterable -> iteration -> push into Array');
})();
Raw
results.txt
stream -> TransformStream -> Writable: 1498.982ms
stream -> iteration -> Writable: 1220.460ms
stream -> TransformStream -> read into Array: 1184.697ms
stream -> iteration -> push into Array: 663.321ms
iterable -> iteration -> push into Array: 361.910ms
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