I have a C++ program that is doing some IO with one shared library (dll). I made a Haskell program that uses ffi for communicating with external dll. With scotty and aeson I made a web-service that communicates with the dll via REST-API (json). I was expecting that the performance would be a bit slower than the c++ internal dll calls, but I'm getting approx 3x slower performance in my haskell program.
I tried to profile it but so far I can see that the bottleneck is Aeson (please correct me if I'm wrong). Is there a way how to optimise it? The data I'm sending via JSON are very small, so that can not be the problem.
ghc -O2 --make Service.hs -o eDS_FM -prof -auto-all -L. -lextlib
Fri Apr 04 23:57 2014 Time and Allocation Profiling Report (Final)
eDS_FM.exe +RTS -p -RTS
total time = 0.81 secs (810 ticks @ 1000 us, 1 processor)
total alloc = 638,446,652 bytes (excludes profiling overheads)
COST CENTRE MODULE %time %alloc
MAIN MAIN 65.3 63.1
go/Number Data.Aeson.Encode 22.5 26.2
array_ Data.Aeson.Parser.Internal 7.0 6.6
tableArrayInDataToJSON.json FM.Json 1.5 0.9
go/Array Data.Aeson.Encode 1.4 1.1
individual inherited
COST CENTRE MODULE no. entries %time %alloc %time %alloc
MAIN MAIN 172 0 65.3 63.1 100.0 100.0
unstream/resize Data.Text.Fusion 419 7 0.0 0.0 0.0 0.0
main.arrayDouble Main 415 2158 0.0 0.2 0.0 0.2
main.retCodeInt Main 414 2158 0.0 0.0 0.0 0.0
main.dataOut Main 413 2158 0.0 0.0 0.0 0.0
getarray.paramLength FM.ModelIO 408 2158 0.0 0.0 0.0 0.0
getarray FM.ModelIO 407 2158 0.1 0.7 0.1 0.7
getarray.rowsReturnedInt FM.ModelIO 412 2158 0.0 0.0 0.0 0.0
getarray.arrayPtr FM.ModelIO 411 2158 0.0 0.0 0.0 0.0
main.resultInt Main 396 1 0.0 0.0 0.0 0.0
main.resultInt Main 395 1 0.0 0.0 0.0 0.0
setmodulestring FM.ModelIO 391 1 0.0 0.0 0.0 0.0
setmodulestring.setVarInArray FM.ModelIO 394 1 0.0 0.0 0.0 0.0
setmodulestring.cValueLength FM.ModelIO 393 1 0.0 0.0 0.0 0.0
setmodulestring.cParamLength FM.ModelIO 392 1 0.0 0.0 0.0 0.0
main.queryString Main 385 1 0.0 0.0 0.0 0.0
stringDataToJSON FM.Json 386 1 0.0 0.0 0.0 0.0
stringDataToJSON.json FM.Json 388 1 0.0 0.0 0.0 0.0
object_ Data.Aeson.Parser.Internal 389 0 0.0 0.0 0.0 0.0
jstring_ Data.Aeson.Parser.Internal 390 4 0.0 0.0 0.0 0.0
stringDataToJSON.retValue FM.Json 387 1 0.0 0.0 0.0 0.0
main.resultInt Main 382 290 0.0 0.0 0.0 0.0
go/Object Data.Aeson.Encode 379 2553 0.0 0.1 24.1 27.5
go/Array Data.Aeson.Encode 416 2158 1.2 0.8 21.7 26.2
go/Number Data.Aeson.Encode 418 63801 20.5 25.4 20.5 25.4
go/Number Data.Aeson.Encode 383 2656 0.1 0.1 0.1 0.1
string Data.Aeson.Encode 380 4814 0.1 0.1 2.2 1.1
go/Number Data.Aeson.Encode 384 0 1.9 0.8 2.0 1.0
go/Array Data.Aeson.Encode 417 0 0.1 0.2 0.1 0.2
break Data.Aeson.Encode 381 4814 0.1 0.0 0.1 0.0
setmoduletable FM.ModelIO 372 290 0.2 0.0 0.4 0.1
setmoduletable.cRows FM.ModelIO 376 290 0.0 0.0 0.0 0.0
setmoduletable.cColumns FM.ModelIO 375 290 0.0 0.0 0.0 0.0
setmoduletable.cParamLength FM.ModelIO 374 290 0.1 0.0 0.1 0.0
setmoduletable.cTable FM.ModelIO 373 290 0.0 0.0 0.0 0.0
main.queryString Main 363 290 0.0 0.0 9.6 7.7
tableArrayInDataToJSON FM.Json 364 290 0.0 0.0 9.6 7.7
tableArrayInDataToJSON.json FM.Json 366 290 1.5 0.9 9.6 7.7
object_ Data.Aeson.Parser.Internal 368 0 0.1 0.0 8.1 6.8
jstring_ Data.Aeson.Parser.Internal 369 1450 1.0 0.2 8.0 6.8
array_ Data.Aeson.Parser.Internal 371 0 7.0 6.6 7.0 6.6
tableArrayInDataToJSON.retValue FM.Json 365 290 0.0 0.0 0.0 0.0
main Main 345 0 0.2 0.7 0.2 0.7
run FM.ModelIO 398 0 0.0 0.0 0.0 0.0
run.result FM.ModelIO 405 103 0.0 0.0 0.0 0.0
run.timeTotal FM.ModelIO 404 103 0.0 0.0 0.0 0.0
run.retData FM.ModelIO 403 103 0.0 0.0 0.0 0.0
CAF GHC.Integer.Logarithms.Internals 343 0 0.0 0.0 0.0 0.0
CAF GHC.Float.ConversionUtils 340 0 0.0 0.0 0.0 0.0
CAF GHC.IO.Encoding.CodePage 327 0 0.0 0.0 0.0 0.0
CAF GHC.Conc.Windows 317 0 0.0 0.0 0.0 0.0
CAF GHC.TopHandler 315 0 0.0 0.0 0.0 0.0
CAF GHC.Float 312 0 0.0 0.0 0.0 0.0
CAF Data.Fixed 301 0 0.0 0.0 0.0 0.0
CAF GHC.IO.Handle.FD 299 0 0.0 0.0 0.0 0.0
CAF GHC.IO.Encoding 295 0 0.0 0.0 0.0 0.0
CAF GHC.IO.Exception 294 0 0.1 0.0 0.1 0.0
CAF Data.Text.Lazy.Builder.Int.Digits 282 0 0.0 0.0 0.0 0.0
CAF Data.Text.Array 275 0 0.0 0.0 0.0 0.0
CAF Data.Text.Internal 274 0 0.0 0.0 0.0 0.0
CAF System.Locale 269 0 0.0 0.0 0.0 0.0
CAF Data.Scientific 268 0 0.0 0.0 0.0 0.0
CAF Data.Time.LocalTime.TimeOfDay 265 0 0.0 0.0 0.0 0.0
CAF Data.Time.Clock.POSIX 263 0 0.0 0.0 0.0 0.0
CAF Data.Aeson.Parser.Internal 256 0 0.0 0.0 0.0 0.0
array_ Data.Aeson.Parser.Internal 370 1 0.0 0.0 0.0 0.0
object_ Data.Aeson.Parser.Internal 367 1 0.0 0.0 0.0 0.0
CAF Blaze.ByteString.Builder.HTTP 249 0 0.0 0.0 0.0 0.0
CAF Network.HTTP.Types.Header 227 0 0.0 0.0 0.0 0.0
CAF Network.HTTP.Types.URI 226 0 0.0 0.0 0.0 0.0
CAF Network.HTTP.Types.Status 225 0 0.0 0.0 0.0 0.0
CAF Network.HTTP.Types.Method 224 0 0.0 0.0 0.0 0.0
CAF Network.Socket 220 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Parse 211 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.RequestHeader 203 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.ResponseHeader 202 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Date 199 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Request 197 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Response 196 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Recv 194 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Header 193 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Types 191 0 0.0 0.0 0.0 0.0
CAF Network.Wai.Handler.Warp.Settings 189 0 0.0 0.0 0.0 0.0
CAF Web.Scotty.Trans 187 0 0.0 0.0 0.0 0.0
CAF Web.Scotty.Route 186 0 0.0 0.0 0.0 0.0
CAF Web.Scotty.Types 185 0 0.0 0.0 0.0 0.0
unstreamChunks/inner Data.Text.Lazy.Fusion 349 0 0.0 0.0 0.0 0.0
unstreamChunks/outer Data.Text.Lazy.Fusion 350 1 0.0 0.0 0.0 0.0
CAF Web.Scotty.Action 184 0 0.0 0.0 0.0 0.0
unstreamChunks/outer Data.Text.Lazy.Fusion 353 4 0.0 0.0 0.0 0.0
unstreamChunks/inner Data.Text.Lazy.Fusion 354 28 0.0 0.0 0.0 0.0
unstreamChunks/resize Data.Text.Lazy.Fusion 355 5 0.0 0.0 0.0 0.0
CAF Main 182 0 0.0 0.0 0.0 0.0
unstreamChunks/outer Data.Text.Lazy.Fusion 406 1 0.0 0.0 0.0 0.0
main.resultInt Main 360 1 0.0 0.0 0.0 0.0
main Main 344 1 0.0 0.0 0.0 0.0
go/Object Data.Aeson.Encode 357 1 0.0 0.0 0.0 0.0
go/Number Data.Aeson.Encode 361 1 0.0 0.0 0.0 0.0
string Data.Aeson.Encode 358 1 0.0 0.0 0.0 0.0
go/Number Data.Aeson.Encode 362 0 0.0 0.0 0.0 0.0
break Data.Aeson.Encode 359 1 0.0 0.0 0.0 0.0
unstreamChunks/outer Data.Text.Lazy.Fusion 346 10 0.0 0.0 0.0 0.0
unstreamChunks/inner Data.Text.Lazy.Fusion 347 104 0.0 0.0 0.0 0.0
unstreamChunks/resize Data.Text.Lazy.Fusion 348 20 0.0 0.0 0.0 0.0
CAF FM.Json 180 0 0.1 0.0 0.1 0.0
unstream/resize Data.Text.Fusion 356 14 0.0 0.0 0.0 0.0
CAF FM.ModelIO 179 0 0.0 0.0 0.0 0.0
getarray FM.ModelIO 409 0 0.0 0.0 0.0 0.0
getarray.rows FM.ModelIO 410 1 0.0 0.0 0.0 0.0
run.timeTot FM.ModelIO 399 1 0.0 0.0 0.0 0.0
run FM.ModelIO 397 1 0.0 0.0 0.0 0.0
run.runType FM.ModelIO 402 1 0.0 0.0 0.0 0.0
run.timeNow FM.ModelIO 401 1 0.0 0.0 0.0 0.0
run.timeTot FM.ModelIO 400 0 0.0 0.0 0.0 0.0
setmoduletable FM.ModelIO 377 0 0.0 0.0 0.0 0.0
setmoduletable.firstTimeStepAfterRestart FM.ModelIO 378 1 0.0 0.0 0.0 0.0
initfm FM.ModelIO 351 1 0.0 0.0 0.0 0.0