@socket-mesh/writable-consumable-stream
v4.2.9
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An async stream which can be iterated over using a for-await-of loop.
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writable-consumable-stream
An async stream which can be iterated over using a for-await-of loop and which can be written to.
The WritableConsumableStream
class extends the ConsumableStream
class.
See https://github.com/SocketCluster/consumable-stream
Installation
npm install @socket-mesh/writable-consumable-stream
Usage
Require
const WritableConsumableStream = require('writable-consumable-stream');
Consume a stream and write to it asynchronously:
let consumableStream = new WritableConsumableStream();
async function consumeAsyncIterable(asyncIterable) {
// Consume iterable data asynchronously.
for await (let packet of asyncIterable) {
console.log('Packet:', packet);
}
}
consumeAsyncIterable(consumableStream);
setInterval(() => {
// Write data to the stream asynchronously,
consumableStream.write(`Timestamp: ${Date.now()}`);
}, 100);
Consume a stream using a while loop:
let consumableStream = new WritableConsumableStream();
async function consumeAsyncIterable(asyncIterable) {
// Consume iterable data asynchronously.
// Works in older environments.
let asyncIterator = asyncIterable.createConsumer();
while (true) {
let packet = await asyncIterator.next();
if (packet.done) break;
console.log('Packet:', packet.value);
}
}
consumeAsyncIterable(consumableStream);
setInterval(() => {
// Write data to the stream asynchronously,
consumableStream.write(`Timestamp: ${Date.now()}`);
}, 100);
Consume a filtered stream using an async generator:
let consumableStream = new WritableConsumableStream();
// Creates an async generator which only produces packets which are allowed by the
// specified filterFunction.
async function* createFilteredStreamGenerator(fullStream, filterFunction) {
for await (let packet of fullStream) {
if (filterFunction(packet)) {
yield packet;
}
}
}
async function consumeAsyncIterable(asyncIterable) {
// Consume iterable data asynchronously.
for await (let packet of asyncIterable) {
console.log('Packet:', packet);
}
}
// The filter function will only include strings which end with the number 5.
function filterFn(data) {
return /5$/.test(data);
}
let filteredStreamGenerator = createFilteredStreamGenerator(consumableStream, filterFn);
consumeAsyncIterable(filteredStreamGenerator);
setInterval(() => {
// Write data to the stream asynchronously,
consumableStream.write(`Timestamp: ${Date.now()}`);
}, 100);
Consume only the next data object which will be written to the stream:
let consumableStream = new WritableConsumableStream();
(async () => {
let data = await consumableStream.once();
console.log(data);
})();
setInterval(() => {
// Write data to the stream asynchronously,
consumableStream.write(`Timestamp: ${Date.now()}`);
}, 100);
See test/
directory for additional examples.