https://github.com/richardkiss/js_zfec

a JavaScript port of zfec: fast erasure coding
https://github.com/richardkiss/js_zfec

Last synced: 8 months ago
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a JavaScript port of zfec: fast erasure coding

• Host: GitHub
• URL: https://github.com/richardkiss/js_zfec
• Owner: richardkiss
• Created: 2013-06-30T23:33:25.000Z (over 12 years ago)
• Default Branch: master
• Last Pushed: 2013-07-02T01:57:48.000Z (over 12 years ago)
• Last Synced: 2025-02-01T18:22:15.204Z (9 months ago)
• Language: JavaScript
• Size: 113 KB
• Stars: 9
• Watchers: 2
• Forks: 6
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

          
js_zfec

=======

This is a port of zfec https://pypi.python.org/pypi/zfec, a fast erasure codec

for Python, into JavaScript.

Overview

========

This package performs two operations, encoding and decoding. Encoding takes

some input data and expands its size by producing extra "check blocks", also

called "secondary blocks". Decoding takes some data -- any combination of

blocks of the original data (called "primary blocks") and "secondary blocks",

and produces the original data.

The encoding is parameterized by two integers, K and N. N is the total number

of blocks produced, and K is how many of those blocks are necessary to

reconstruct the original data. N is required to be at least 1 and at most

256, and k is required to be at least 1 and at most N.

Usage

=====

The fec.js file exports the symbol "fec".

Create an instance, passing in K and N.

        // To encode:

        var array_of_uint8

        var f = fec(3, 10);

        var encoded = f.encode(array_of_uint8);

        // encoded now contains 10 arrays of uint8, each just over 1/3rd the size

        // of the original array_of_uint8 array.

        // To decode

        // three arbitrary parts, from above

        var f = fec(3, 10);

        var parts = [encoded[3], encoded[6], encoded[7]];

        var decoded = f.decode(parts);

        // now, decoded will equal the original array_of_uint8 above.

The data produced is compatible with the Python-based command-line tools

zfec and zunfec.