BJSON is a binary JSON encoding, essentially maintaining the same structure as JSON, but with support for embedding binary blobs.
You can encode any JSON document in BJSON and must BJSON documents in JSON.
However, encoding binary data, such as images, is not supported by JSON.stringify,
and methods typically used for encoding binary data in JSON have a large overhead.
With BJSON you can serialize JSON objects containing typed arrays (ArrayBuffer)
to binary data. Futhermore, a BJSON encoding is typically 5-10% shorter than the
conventional string encoding of JSON objects.
For more information on BJSON and BJSON.coffee, take a look at the following links.
- The BJSON specification
- The BJSON.coffee browser compatibility testing page
- My blog post introducing BJSON.coffee
- Performance comparison of JSON.stringify and BJSON.serialize
The official BJSON specification dictates the support for 64 bit integers, and the option to encode size fields using a 64 bit integer. However, as number in Javascript and, hence, JSON are 64 bit floats, BJSON.coffee does not support integers beyond 53 bit. For size fields this is 9 Petabyte, which isn't a problem, but for 64 bit integers larger than 2^53 precision will be lost. Also note that BJSON.coffee encodes integers larger than 2^32 as 64 bit floats.
BJSON.coffee is released under the Apache License 2.0.
For UTF-8 string encoding BJSON.coffee uses encoding.js which is a modified version of the string
encoding shim provided by stringencoding, which is also
licensed under the Apache License 2.0.