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@smockle
Last active June 20, 2019 21:29
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Bluebird.prototype.map with native Promises
#!/usr/bin/env node
//@ts-check
const MAX_CONCURRENCY = 3;
function sayHiAsync() {
console.log("marco");
return new Promise((resolve) => {
console.log("polo");
setTimeout(() => {
console.log("bravo");
resolve("Hi!");
}, 2000)
})
}
async function concurrentPromises(inputs, promiseFactory, concurrency) {
try {
let results = [];
while (inputs.length > 0) {
const iterationInputs = inputs.splice(0, Math.min(inputs.length, concurrency));
const iterationPromises = iterationInputs.map((input) => promiseFactory(input));
console.log(`Evaluating: ${iterationPromises.length}. Evaluated: ${results.length}. Remaining: ${inputs.length}.`);
const iterationResults = await Promise.all(iterationPromises);
console.log(iterationResults);
results = results.concat(iterationResults);
}
return results;
} catch (error) {
throw error;
}
}
(async () => {
const recipients = Array.from(new Array(10));
let results = await concurrentPromises(recipients, sayHiAsync, MAX_CONCURRENCY);
results.forEach((result) => console.log(result));
})();
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