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6356 :: NIM Integration Problems with Server Side Postgres

• panchove (orginal) [2020-05-20T15:10:23+02:00] view original

  Hello everyone

  I am trying to integrate two server side test functions with Postgres the first one, nimAddOne (int): int works fine integrate it like this:

  # AddOne adds one to the given arg and retuns it
  proc nimAddOne (i: cint): cint {.exportc.} =
      result = i + 1
  Run

  I made the call from C this way:

  #include "postgres.h"
  #include "fmgr.h"
  #undef HAVE_STDINT_H
  #include "converter.h"
  
  PG_FUNCTION_INFO_V1 (c_addone);
  
  Datum
  c_addone (PG_FUNCTION_ARGS)
  {
  int32 arg = PG_GETARG_INT32 (0);
  int32 result = nimAddOne (arg);
  PG_RETURN_INT32 (result);
  }
  Run

  But when I pass strings to another function like this:

  # ConcatName concat name and last name
  proc nimConcatName (name, last: cstring): cstring {.exportc.} =
      var r: cstring
      r = $ name & "" & $ last
      result = r
  Run

  And calling it from C like this

  #include "postgres.h"
  #include "fmgr.h"
  #include "utilities.h"
  #undef HAVE_STDINT_H
  #include "converter.h"
  
  PG_FUNCTION_INFO_V1 (c_fullname);
  
  Datum
  c_fullname (PG_FUNCTION_ARGS)
  {
  
      text * ptrName = PG_GETARG_TEXT_PP (0);
      text * ptrLast = PG_GETARG_TEXT_PP (1);
  
      const char * name = GetStringFromText (ptrName);
      const char * last = GetStringFromText (ptrLast);
  
      char * result = nimConcatName ((char *) name, (char *) last);
  
      elog (INFO, "% s", result);
  
      text * ptrResult = (text *) GetTextFromString (result);
  
      PG_RETURN_TEXT_P (ptrResult);
  }
  Run

  Postgres server goes down hopelessly

  Could you tell me what I do wrong in the second function?

  Thank you!

  NOTES: "converter.h" contains the base NIM types after compiling the "converter.nim" file that contains both functions

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• cdome (orginal) [2020-05-20T15:40:41+02:00] view original

  Do you compile to shared library? Things to check: You do call NimMain or setupForeignThreadGC.

  Another thing I recommend trying is to compile with --gc:arc -d:useMalloc this gives you garbage collection free environment that will ease integration with postgres.

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• panchove (orginal) [2020-05-20T15:49:45+02:00] view original

  Hello, thanks for answering

  I compile and link in this way

  $ (MY_LIB_NIM): * .nim Makefile
           nim c -d: release --passC: -fPIC --noMain --opt: speed --app: staticlib --outdir: $ (NIM_OUTDIR) --nimcache: $ (NIM_CACHEDIR) --out: $ (basename $ < ) .a --header: $ (basename $ <). h $ <
  
  % .o:% .c Makefile
           gcc -std = c11 -fPIC -O2 -D_GNU_SOURCE -c $ <-I $ (PG_SERVER_INC) -I $ (NIM_INCLUDE_BASE) -I $ (NIM_INCLUDE_LOCAL)
  
  $ (MY_LIB_GCC): $ (MY_OBJS)
           gcc -shared -fPIC -O2 $ ^ $ (MY_LIB_NIM) -o $ @
  
  Run

  I will test with the parameters you indicate

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• JPLRouge (orginal) [2020-05-20T15:50:32+02:00] view original

  hello:

  -d:useMalloc

  I feel like I'm faster, is true

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• panchove (orginal) [2020-05-20T16:07:25+02:00] view original

  Good news:

  It worked perfectly !!

  Thanks to both!

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