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Calculate CRC-32 without zlib.crc32() binding in NodeJS
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| private static crc32(data: fsPromises.FileHandle | Uint8Array): Promise<number> { | |
| return new Promise((resolve, reject) => { | |
| let inStream: stream.Readable; | |
| try { | |
| if (data instanceof Uint8Array) { | |
| inStream = new stream.PassThrough().end(data); | |
| } else { | |
| inStream = data.createReadStream({ start: 0, autoClose: false, highWaterMark: this.chunkSize }); | |
| } | |
| } catch (e) { | |
| reject(e); | |
| return; | |
| } | |
| let gzip = zlib.createGzip({ level: 0, chunkSize: this.chunkSize }); | |
| let lastChunk: Buffer; | |
| let outStream = new stream.Writable({ | |
| write: (chunk, encoding, callback) => { lastChunk = chunk; callback(); }, | |
| writev: (chunks, callback) => { lastChunk = chunks[chunks.length - 1].chunk; callback(); }, | |
| highWaterMark: this.chunkSize, | |
| }); | |
| outStream.on('close', () => { | |
| let dv = new DataView(lastChunk.buffer, lastChunk.byteOffset, lastChunk.byteLength); | |
| let crc32 = dv.getUint32(dv.byteLength - 8, true); | |
| resolve(crc32); | |
| }); | |
| stream.pipeline(inStream, gzip, outStream, (err) => { reject(err); }); | |
| }); | |
| } |
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