Created
February 24, 2025 18:59
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| import crypto from 'crypto' | |
| import fs from 'fs' | |
| const chunkSize = 16777216; | |
| console.log(await calculateForFile('video.mp4', chunkSize)); | |
| function calculateForFile(filename, chunkSize) { | |
| return new Promise((resolve, reject) => { | |
| const stream = fs.createReadStream(filename, { highWaterMark: chunkSize }); | |
| calculate(stream, chunkSize) | |
| .then(resolve) | |
| .catch(reject); | |
| }); | |
| } | |
| async function calculate(stream, chunkSize) { | |
| const dataSize = await getStreamSize(stream); | |
| let sumOfSums = []; | |
| let parts = 0; | |
| let position = 0; | |
| while (position < dataSize) { | |
| let length = chunkSize; | |
| if (position + chunkSize > dataSize) { | |
| length = dataSize - position; | |
| } | |
| const sum = await md5sum(stream, position, length); | |
| sumOfSums.push(sum); | |
| parts++; | |
| position += length; | |
| } | |
| let finalSum; | |
| if (parts === 1) { | |
| finalSum = sumOfSums[0]; | |
| } else { | |
| finalSum = crypto.createHash('md5').update(Buffer.concat(sumOfSums)).digest(); | |
| } | |
| let sumHex = finalSum.toString('hex'); | |
| if (parts > 1) { | |
| sumHex += '-' + parts; | |
| } | |
| return sumHex; | |
| } | |
| function md5sum(stream, start, length) { | |
| return new Promise((resolve, reject) => { | |
| const hash = crypto.createHash('md5'); | |
| const buffer = Buffer.alloc(length); | |
| const fd = fs.openSync(stream.path, 'r'); | |
| fs.read(fd, buffer, 0, length, start, (err, bytesRead, buf) => { | |
| if (err) return reject(err); | |
| hash.update(buf.slice(0, bytesRead)); | |
| fs.closeSync(fd); | |
| resolve(hash.digest()); | |
| }); | |
| }); | |
| } | |
| function getStreamSize(stream) { | |
| return new Promise((resolve, reject) => { | |
| fs.stat(stream.path, (err, stats) => { | |
| if (err) return reject(err); | |
| resolve(stats.size); | |
| }); | |
| }); | |
| } |
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