Streams
Streams, LARGE, DATA, ko, SMALL, CHUNKS, mein, PROCESS, karne, DETE, HAIN, BINA, POORE, DATA, ko, MEMORY, mein, LOAD, kiye — Node.js, mein, CHAAR, TYPES, HOTE, HAIN, Readable, Writable, Duplex, aur, Transform.
fs.createReadStream()/createWriteStream(), LARGE, FILES, ke, liye, IDEAL, HAIN — jaise, EK, 2GB, VIDEO, FILE, ko, readFile() se, PADHNA, POORI, MEMORY, EXHAUST, kar, sakta hai, LEKIN, STREAM, se, EK, TIME, PAR, SIRF, KUCH, KB, MEMORY, mein, HOTA hai.
const fs = require("fs");
const readStream = fs.createReadStream("large-file.txt", { encoding: "utf8" });
const writeStream = fs.createWriteStream("output.txt");
readStream.on("data", (chunk) => {
console.log("Received chunk of size:", chunk.length);
writeStream.write(chunk.toUpperCase());
});
readStream.on("end", () => console.log("Reading complete"));
readStream.on("error", (err) => console.error("Error:", err));- Streams = data, ko, chunks, mein, process, karte, hain, bina, poora, load, kiye
- 4 types: Readable, Writable, Duplex, Transform
- Large files (video, logs) ke, liye, streams, ZAROORI, HAIN — memory, efficient
Transform, STREAMS, DATA, ko, READ, karte, waqt, MODIFY, karte, HAIN (jaise, COMPRESSION, ENCRYPTION) — CUSTOM, Transform, STREAM, banaне, ke, liye, _transform() METHOD, IMPLEMENT, kiya, jaata hai.
const { Transform } = require("stream");
const upperCase = new Transform({
transform(chunk, encoding, callback) {
callback(null, chunk.toString().toUpperCase());
},
});
process.stdin.pipe(upperCase).pipe(process.stdout);Readable, streams, "data" (chunk, aaya), "end" (KOI, aur, data, NAHI), aur, "error" EVENTS, EMIT, karte, HAIN. Writable, streams, "finish" (SAARA, DATA, FLUSHED, ho, gaya) EVENT, EMIT, karti, HAIN.