Adding a NIF based JSON decoding/encoding module ------------------------------------------------
Key: COUCHDB-1118 URL: https://issues.apache.org/jira/browse/COUCHDB-1118 Project: CouchDB Issue Type: Improvement Components: Database Core Reporter: Filipe Manana Fix For: 1.2 Currently, all the Erlang based JSON encoders and decoders are very slow, and decoding and encoding JSON is something that we do basically everywhere. Via IRC, it recently discussed about adding a JSON NIF encoder/decoder. Damien also started a thread at the development mailing list about adding NIFs to trunk. The patch/branch at [1] adds such a JSON encoder/decoder. It is based on Paul Davis' eep0018 project [2]. Damien made some modifications [3] to it mostly to add support for big numbers (Paul's eep0018 limits the precision to 32/64 bits) and a few optimizations. I made a few corrections and minor enhancements on top of Damien's fork as well [4]. Finally BenoƮt identified some missing capabilities compared to mochijson2 (on encoding, allow atoms as strings and strings as object properties). Also, the version added in the patch at [1] uses mochijson2 when the C NIF is not loaded. Autotools configuration was adapted to compile the NIF only when we're using an OTP release >= R13B04 (R13B03 NIF API is too limited and suffered many changes compared to R13B04 and R14) - therefore it should work on any OTP release > R13B at least. I successfully tested this on R13B03, R13B04 and R14B02 in an Ubuntu environment. I'm not sure if it builds at all on Windows - would appreciate if someone could verify it. Also, I'm far from being good with the autotools, so I probably missed something important or I'm doing something in a not very standard way. This NIF encoder/decoder is about one order of magnitude faster compared to mochijson2 and other Erlang-only solutions such as jsx. A read and writes test with relaximation shows this has a very positive impact, specially on reads (the EJSON encoding is more expensive than JSON decoding) - http://graphs.mikeal.couchone.com/#/graph/698bf36b6c64dbd19aa2bef634052381 @Paul, since this is based on your eep0018 effort, do you think any other missing files should be added (README, etap tests, etc)? Also, should we put somewhere a note this is based on your project? [1] - https://github.com/fdmanana/couchdb/compare/json_nif [2] - https://github.com/davisp/eep0018 [3] - https://github.com/Damienkatz/eep0018/commits/master [4] - https://github.com/fdmanana/eep0018/commits/final_damien -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira