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A new week, a new JSON performance improvement

March 22nd, 2011 by

It’s been a few weeks since I last wrote about the aeson library for working with JSON in Haskell, but this isn’t because I’ve been idle. In fact, just tonight I put out a new release. Where the previous releases focused on parsing performance, this one focuses on encoding performance.

And the performance news is good: on real-world data, I’ve improved encoding performance by about a factor of 4. Why don’t we let the graphs do the talking.

Encoding performance

Enjoy!

5 Comments »

5 Responses to “A new week, a new JSON performance improvement”

  1. on 22 Mar 2011 at 10:461 Holger

    Thanks for the amazing work.
    Unfortunately, there seems to be a bug in the new version. If I enter “encode $ Number 200″ the result is “0D”, where the old version correctly returned “200″.

  2. on 22 Mar 2011 at 14:452 Bryan O'Sullivan

    Holger, oops! You’re right. I swapped a “quot” and a “rem” by accident. I’ve released 0.3.2.1 and added a QuickCheck test suite, so this shouldn’t happen again :-)

  3. on 22 Mar 2011 at 15:263 Simon Meier

    Thats a very nice improvement. As you’re using the blaze-builder library, I had a go at converting your string encoding to use the ‘Write’ construction:

    https://github.com/meiersi/aeson/commit/328777ef0ad1e1e9d7a730bd16753384db5f5ec0

    Together with a function for efficiently serializing Text values using the internals of your Fusion framework, which I just exported in a local dev version

    https://github.com/meiersi/aeson/commit/1bcd9f7605cf61abe2faf7ff53b1f8aa91fd3f48

    this results in another 50% speedup on your newly released aeson-0.3.2.0 library:

    https://gist.github.com/881389

    The current code is not as nice as it could be, as it defines functions that were better provided by the ‘text’ or ‘blaze-builder’ libraries. Especially, for the second patch, I’m not sure, if it should be included in aeson right now. The integration of the ‘blaze-builder’ work into ‘bytestring’ will solve these issues. However, progress is steady but not all too fast on that side.

  4. on 22 Mar 2011 at 16:444 Bryan O'Sullivan

    Simon, those performance improvements look great!

    I think that the fromWriteText function would be best in blaze-builder, as I can’t add it to text due to the dependency it would add on a non-platform library.

    Let me know when you release a new blaze-builder with that addition, as the added performance would be fabulous to have. What version of GHC are you benchmarking with, by the way?

  5. on 22 Mar 2011 at 19:335 Simon Meier

    Hi Bryan,

    I’m benchmarking on a Core 2 Duo 2.2 GHz using GHC 7.0.2.

    The problem with the ‘fromWriteText’ function is that it depends on the hidden ‘Text.Fusion’ module. Hence, I first need an updated version of the ‘text’ library. Once, you expose this module, I’ll add it to blaze-builder.

    The ‘hex’ functions will have to wait with respect to blaze-builder. The plan is to incorporate them only in the new ‘bytestring’ library. Otherwise, my forces are getting spread too thin.

    BTW: Could you send me a mail when you respond? I was hoping your blogging system would do that automatically, but it is not.

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