5.8 KiB
Binary Formats
Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance, over a network. Hence, the library supports
- BJData (Binary JData),
- BON8 (Binary Object Notation 8),
- BSON (Binary JSON),
- CBOR (Concise Binary Object Representation),
- MessagePack, and
- UBJSON (Universal Binary JSON)
to efficiently encode JSON values to byte vectors and to decode such vectors.
Comparison
Completeness
| Format | Serialization | Deserialization |
|---|---|---|
| BJData | complete | incomplete: no column-major ND-arrays, no Draft 4 SoA/extension types |
| BON8 | incomplete: no unsigned integers above int64 | complete |
| BSON | incomplete: top-level value must be an object | incomplete, but all JSON types are supported |
| CBOR | complete | incomplete, but all JSON types are supported |
| MessagePack | complete | incomplete, but all JSON types are supported |
| UBJSON | complete | complete |
Binary values
| Format | Binary values | Binary subtypes |
|---|---|---|
| BJData | supported (Draft 3 only) | not supported |
| BON8 | not supported | not supported |
| BSON | supported | supported |
| CBOR | supported | supported |
| MessagePack | supported | supported |
| UBJSON | not supported | not supported |
See binary values for more information.
Sizes
| Format | canada.json | twitter.json | citm_catalog.json | jeopardy.json |
|---|---|---|---|---|
| BJData | 53.2 % | 91.1 % | 78.1 % | 96.6 % |
| BJData (size) | 58.6 % | 92.1 % | 86.7 % | 97.4 % |
| BJData (size+type) | 58.6 % | 92.1 % | 86.5 % | 97.4 % |
| BON8 | 50.5 % | 83.8 % | 63.5 % | 87.5 % |
| BSON | 85.8 % | 95.2 % | 95.8 % | 106.7 % |
| CBOR | 50.5 % | 86.3 % | 68.4 % | 88.0 % |
| MessagePack | 50.5 % | 86.0 % | 68.5 % | 87.9 % |
| UBJSON | 53.2 % | 91.3 % | 78.2 % | 96.6 % |
| UBJSON (size) | 58.6 % | 92.3 % | 86.8 % | 97.4 % |
| UBJSON (size+type) | 55.9 % | 92.3 % | 85.0 % | 95.0 % |
Size of each test file in each format, in percent of the minified JSON value; the smallest size per file is printed in bold. The (size) and (size+type) rows are written with the use_size and use_type options of to_bjdata and to_ubjson.
The table above as charts: size per base format relative to minified JSON (vertical line at 100 %); the smallest format per file is drawn in a stronger colour than the others. The size and size+type variants of BJData and UBJSON are omitted here; see the table.
See also
cbor_tag_handler_t- how CBOR tags are handled when parsingJSON_STRICT_BINARY_UTF8- reject ill-formed UTF-8 in strings- Binary values - binary values and subtypes
to_cbor- /from_cbor,to_msgpack/from_msgpack,to_bson/from_bson,to_ubjson/from_ubjson,to_bjdata/from_bjdata,to_bon8/from_bon8- the conversion functions- Parsing untrusted input - harden an application that parses untrusted binary data
- SAX interface - decode binary formats without building a value