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apache / couchdb-jiffy / refs/tags/0.11.0
commiteb70deb8317cb04d09eed5a298123e6f6d00d6e3[log] [tgz]
authorPaul J. Davis <paul.joseph.davis@gmail.com>Mon Jun 16 21:39:49 2014 -0500
committerPaul J. Davis <paul.joseph.davis@gmail.com>Mon Jun 16 21:40:26 2014 -0500
treeffaab50678f21fa6f232ecd91b4d795333eeb9e9
parenta232221c4249d31ea09dae730d556401392a98a6 [diff]
Fix timeouts for short doubles

Timeouts apparently don't actually work unless you use a test generator.
Which makes sense in hindsight.
1 file changed
tree: ffaab50678f21fa6f232ecd91b4d795333eeb9e9
  1. c_src/
  2. plugins/
  3. src/
  4. test/
  5. .gitignore
  6. .travis.yml
  7. LICENSE
  8. Makefile
  9. README.md
  10. rebar
  11. rebar.config
  12. rebar.config.script
README.md

Jiffy - JSON NIFs for Erlang

A JSON parser as a NIF. This is a complete rewrite of the work I did in EEP0018 that was based on Yajl. This new version is a hand crafted state machine that does its best to be as quick and efficient as possible while not placing any constraints on the parsed JSON.

Build Status

Usage

Jiffy is a simple API. The only thing that might catch you off guard is that the return type of jiffy:encode/1 is an iolist even though it returns a binary most of the time.

A quick note on unicode. Jiffy only understands UTF-8 in binaries. End of story.

Errors are raised as exceptions.

Eshell V5.8.2  (abort with ^G)
1> jiffy:decode(<<"{\"foo\": \"bar\"}">>).
{[{<<"foo">>,<<"bar">>}]}
2> Doc = {[{foo, [<<"bing">>, 2.3, true]}]}.
{[{foo,[<<"bing">>,2.3,true]}]}
3> jiffy:encode(Doc).
<<"{\"foo\":[\"bing\",2.3,true]}">>

jiffy:decode/1,2

  • jiffy:decode(IoData)
  • jiffy:decode(IoData, Options)

The options for decode are:

  • {bytes_per_iter, N} where N >= 0 - This controls the number of bytes that Jiffy will process before yielding back to the VM. The mechanics of this yield are completely hidden from the end user.

jiffy:encode/1,2

  • jiffy:encode(EJSON)
  • jiffy:encode(EJSON, Options)

where EJSON is a valid representation of JSON in Erlang according to the table below.

The options for encode are:

  • uescape - Escapes UTF-8 sequences to produce a 7-bit clean output
  • pretty - Produce JSON using two-space indentation
  • force_utf8 - Force strings to encode as UTF-8 by fixing broken surrogate pairs and/or using the replacement character to remove broken UTF-8 sequences in data.
  • {bytes_per_iter, N} where N >= 0 - This controls the number of bytes that Jiffy will generate before yielding back to the VM. The mechanics of this yield are completely hidden from the end user.

Data Format

Erlang                          JSON            Erlang
==========================================================================

null                       -> null           -> null
true                       -> true           -> true
false                      -> false          -> false
"hi"                       -> [104, 105]     -> [104, 105]
<<"hi">>                   -> "hi"           -> <<"hi">>
hi                         -> "hi"           -> <<"hi">>
1                          -> 1              -> 1
1.25                       -> 1.25           -> 1.25
[]                         -> []             -> []
[true, 1.0]                -> [true, 1.0]    -> [true, 1.0]
{[]}                       -> {}             -> {[]}
{[{foo, bar}]}             -> {"foo": "bar"} -> {[{<<"foo">>, <<"bar">>}]}
{[{<<"foo">>, <<"bar">>}]} -> {"foo": "bar"} -> {[{<<"foo">>, <<"bar">>}]}

Improvements over EEP0018

Jiffy should be in all ways an improvemnt over EEP0018. It no longer imposes limits on the nesting depth. It is capable of encoding and decoding large numbers and it does quite a bit more validation of UTF-8 in strings.