Le Mon, 01 Dec 2014, Thomas Gazagnaire a écrit :
> Do you have any benchmarks to compare CConv and similar camlp4 generators?

Hi Thomas,

I hadn't, but I just wrote very basic ones to compare with
ppx_deriving_yojson (should be similar to camlp4). The code is at
https://github.com/c-cube/cconv/blob/e80ab0e6c458a01b419ea69c7f41d0a350aebbad/bench/run_bench.ml

It only compares times for encoding into Json right now, with the
following results (recursive records first, recursive terms then;
"manual" is a handwritten encoding function, "cconv" the combinators
version, and "deriving_yojson" uses @whitequark's nice deriver):

% ./run_bench.native

benchmark points
Throughputs for "manual", "cconv", "deriving_yojson" each running for at least 4 CPU seconds:
         manual:  4.20 WALL ( 4.20 usr +  0.00 sys =  4.20 CPU) @ 3057270.82/s (n=12846652)
          cconv:  4.21 WALL ( 4.21 usr +  0.00 sys =  4.21 CPU) @ 784724.92/s (n=3300553)
deriving_yojson:  4.21 WALL ( 4.21 usr +  0.00 sys =  4.21 CPU) @ 3065779.07/s (n=12891601)
                     Rate           cconv          manual deriving_yojson
          cconv  784725/s              --            -74%            -74%
         manual 3057271/s            290%              --             -0%
deriving_yojson 3065779/s            291%              0%              --

benchmark terms
Throughputs for "manual", "cconv", "deriving_yojson" each running for at least 4 CPU seconds:
         manual:  4.20 WALL ( 4.20 usr +  0.00 sys =  4.20 CPU) @ 1679609.71/s (n=7057720)
          cconv:  4.20 WALL ( 4.20 usr +  0.00 sys =  4.20 CPU) @ 726619.43/s (n=3051075)
deriving_yojson:  4.20 WALL ( 4.20 usr +  0.00 sys =  4.20 CPU) @ 1624740.65/s (n=6822286)
                     Rate           cconv deriving_yojson          manual
          cconv  726619/s              --            -55%            -57%
deriving_yojson 1624741/s            124%              --             -3%
         manual 1679610/s            131%              3%              --


So yeah, unsurprisingly, there is some overhead :(. There is some
dispatching through records-of-functions going on, because combinators
should work with any backend, whereas specialized encoders can build the
result directly.

-- 
Simon

http://weusepgp.info/
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