NodeJS使用文件流解决大文件处理的内存与时间效率问题

const fs = require('fs');

const readStream = fs.createReadStream('largefile.txt', { highWaterMark: 64 * 1024 }); // 每次读取 64KB

readStream.on('data', (chunk) => {
    console.log(`Received ${chunk.length} bytes of data.`);
});

readStream.on('end', () => {
    console.log('File reading completed.');
});

const http = require('http');
const fs = require('fs');

http.createServer((req, res) => {
    const readStream = fs.createReadStream('video.mp4');
    readStream.pipe(res); // 将视频文件流式传输到客户端
}).listen(3000, () => {
    console.log('Server is running on port 3000');
});

const fs = require('fs');

const readStream = fs.createReadStream('input.txt');

readStream.on('data', (chunk) => {
    console.log(`Received ${chunk.length} bytes of data.`);
});

readStream.on('end', () => {
    console.log('No more data to read.');
});

readStream.on('error', (err) => {
    console.error('Error reading file:', err);
});

const fs = require('fs');

const writeStream = fs.createWriteStream('output.txt');

writeStream.write('Hello, World!\n');
writeStream.write('This is a test file.\n');

writeStream.end(() => {
    console.log('File writing completed.');
});

writeStream.on('error', (err) => {
    console.error('Error writing file:', err);
});

const fs = require('fs');

const readStream = fs.createReadStream('input.txt');
const writeStream = fs.createWriteStream('output.txt');

readStream.pipe(writeStream);

writeStream.on('finish', () => {
    console.log('Data has been piped successfully.');
});

const fs = require('fs');

const readStream = fs.createReadStream('largefile.txt');
const writeStream = fs.createWriteStream('output.txt');

readStream.pipe(writeStream);

writeStream.on('drain', () => {
    console.log('Write stream is ready to receive more data.');
});

const fs = require('fs');
const writeStream = fs.createWriteStream('app.log', { flags: 'a' });

function log(message) {
    writeStream.write(`${new Date().toISOString()} - ${message}\n`);
}

log('Server started');
log('User logged in');