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Fast CRC32 computation in TypeScript

ACyclic Redundancy Check (CRC) is a calculation used to detect errors in data transmission.

This library implementsCRC32, the standard 32-bit CRC using the binary polynomial0xEDB88320. This is the same algorithm used inPNG,zlib, and other popular applications.

The following functions are exported from this package:

functioncrc32Init():number;functioncrc32Update(prev:number,data:ArrayBufferView):number;functioncrc32Final(prev:number):number;functioncrc32(data:ArrayBufferView):number;

Note: Since the CRC algorithm works with unsigned data, thecrc32 andcrc32Final functions always returnnon-negative numbers. For example, CRC32(0x01) returns 2768625435 rather than -1526341861.

import{crc32}from"@foxglove/crc";constdata=newUint8Array(...);constcrc=crc32(data);

import{crc32Init,crc32Update,crc32Final}from"@foxglove/crc";letcrc=crc32Init();while(/* more data available */){crc=crc32Update(crc,data);}crc=crc32Final(crc);

This package achieves a >5x performance improvement over many other CRC packages, because of the multi-byte algorithms used (adapted fromhttps://github.com/komrad36/CRC).

The following benchmarks were recorded on a MacBook Pro with an M1 Pro chip and 16GB of RAM. Each iteration ("op") is processing 1MB of data.

$ yarn bench...  crc:    355 ops/s, ±0.56%     | 81.52% slower  node-crc:    376 ops/s, ±0.14%     | 80.43% slower  crc-32:    1 057 ops/s, ±0.16%   | 44.98% slower  polycrc:    327 ops/s, ±0.21%     | slowest, 82.98% slower  this package:    1 921 ops/s, ±0.18%   | fastest

For further information about CRCs and their computation, see:

• https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks
• https://github.com/komrad36/CRC
• https://create.stephan-brumme.com/crc32/
• https://zlib.net/crc_v3.txt
• https://github.com/Michaelangel007/crc32
• https://docs.microsoft.com/en-us/openspecs/office_protocols/ms-abs/06966aa2-70da-4bf9-8448-3355f277cd77

@foxglove/crc is licensed under theMIT License.

1. Runyarn version --[major|minor|patch] to bump version
2. Rungit push && git push --tags to push new tag
3. GitHub Actions will take care of the rest

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