Yet Another Base62
Installing and testing
With npm do:
npm install ya-base62
To run the test suite, run the following command from the ya-base62
directory:
npm test
Features
- First and foremost designed to encode/decode multiple values to/from a structured string.
- Comparatively fast decoding.
- The library doesn't support big numbers (integers encoded on more than 51 bits, > Number.MAX_SAFE_INTEGER).
- The library doesn't support custom charsets (it is hardcoded to
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
which is the default charset of most existing implementations).
Usage
Encoding a structured string
var yabe62 = ; var width = 600 height = 480 value = 12093; var structuredString = yabe62 + yabe62 + yabe62; // '9G7K00000393'
Decoding a structured string
var yabe62 = ; var structuredString = '9G7K00000393'; console; // 600 480 12093
Decoding and encoding unstructured string
var yabe62 = ; console; // '1jdhPa'console; // 1200050000
Public API
The module is exposing 6 pure functions.
sbValueToBase62(value)
Convert an integer value to a single byte base 62 value.
- value : An integer in the [0-61] range.
sbValueFromBase62(string, position)
Convert a single byte base 62 value to an integer.
- string : String containing the single byte base 62 value.
- position : Position of the character to decode.
mbValueToBase62(value, length)
Convert an integer value to a multiple byte base 62 value.
- value : An integer in the [0-(62 ** length - 1)] range.
- length : The number of bytes.
mbValueFromBase62(string, position, length)
Convert a multiple byte base 62 value to an integer.
- string : String containing the multiple byte base 62 value.
- position : Start position of the characters to decode.
- length : Number of bytes to decode.
encode(value)
Convert an integer to a base 62 value.
- value : Positive integer to encode.
decode(string)
Convert the entirety of a given base 62 string to an integer.
- string : String containing the base 62 value to decode.
Benchmark
It should be noted that this benchmark is slightly unfair. The slowness of the other module when encoding can be explained by the fact that they allow the use of custom charset.
Operation | Module | Results | Time elapsed |
---|---|---|---|
decoding (1000000x) | ya-base62@1.0.0 | correct | 97.88 ms |
decoding (1000000x) | base62@1.1.2 | correct | 2149.35 ms |
decoding (1000000x) | base62.js@0.5.0 | correct | 909.97 ms |
encoding (1000000x) | ya-base62@1.0.0 | correct | 63.78 ms |
encoding (1000000x) | base62@1.1.2 | correct | 57.27 ms |
encoding (1000000x) | base62js@0.5.0 | correct | 86.71 ms |
mbValueToBase62 on 10 characters (1000000x) | ya-base62@1.0.0 | correct | 180.27 ms |
Changelog
1.0.0 (2017.05.14) :
- First implementation
License
MIT