python callback et librairie C

Version imprimable

Bonjour,
Je souhaite utiliser une librairie c :

Code:

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....
typedef struct __pmlist_t PM_LIST;
typedef struct __pmdb_t PM_DB;
..
int pacman_parse_config(char *file, pacman_cb_db_register callback, const char *this_section);
/* Database registration callback */
typedef void (*pacman_cb_db_register)(const char *, PM_DB *);
....

J'ai donc écris :

Code:

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#!/usr/bin/env python
 
import os, tempfile, shutil, sys
from ctypes import *
import ctypes
 
#GLOBAL
pacman=cdll.LoadLibrary("libpacman.so")
CFG_FILE = '/etc/pacman-g2.conf'
 
#for print debug messages
debug=1
 
 
#some class for pacman-g2
class PM_LIST(Structure):
  pass
PM_LIST._fields_ = [
        ("data", ctypes.c_void_p),
        ("prev", POINTER(PM_LIST)),
        ("next", POINTER(PM_LIST)),
        ("last", POINTER(PM_LIST))]
class PM_DB(Structure):
  pass
PM_DB._fields_ = [
        ("path", ctypes.c_char),
        ("treename", ctypes.c_char),
        ("handle", ctypes.c_void_p),
        ("pkgcache", POINTER(PM_LIST)),
        ("grpcache", POINTER(PM_LIST)),
        ("handle", POINTER(PM_LIST)),
        ("servers", ctypes.c_char)]
 
def _db_cb (section,db):
  print_debug(db)
  return
 
def pacman_init():
  pacman.pacman_release()
  if pacman.pacman_initialize("/") == -1:
    print "Can't initialise pacman-g2"
    sys.exit(0) 
 
def pacman_init_database():
  print_debug("init database")
  pacman_cb_db_register = CFUNCTYPE(POINTER(ctypes.c_void_p), POINTER(ctypes.c_char_p), PM_DB)
  print_debug("pacman_parse_config")
  pacman.pacman_parse_config.argtypes = [POINTER(ctypes.c_char_p),POINTER(pacman_cb_db_register),POINTER(ctypes.c_char_p)]
  pacman.pacman_parse_config(CFG_FILE,pacman_cb_db_register(_db_cb),'')
 
def main():
  pacman_init()
  pacman_init_database()
 
 
def help():
  print "help :"
  print "--search Package"
  sys.exit(0)
 
 
def print_debug(textConsole):
  if debug <> 1:
    return
  print "DEBUG : "+textConsole
 
def _db_cb(section , db):
  print db
 
#start main program
main()

Mais quand je lance le script :

Code:

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 DEBUG : init database
DEBUG : pacman_parse_config
Traceback (most recent call last):
  File "py-pacman.py", line 73, in <module>
    main()
  File "py-pacman.py", line 55, in main
    pacman_init_database()
  File "py-pacman.py", line 51, in pacman_init_database
    pacman.pacman_parse_config(CFG_FILE,pacman_cb_db_register(_db_cb),'')
TypeError: invalid result type for callback function

Je me doute que j'ai du me tromper mais je vois pas si quelqu'un à une idée je suis preneur ;)

Bon, j'ai un peu avancé j'avais des problèmes de typage :

Code:

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#!/usr/bin/env python
 
import os, tempfile, shutil, sys
from ctypes import *
import ctypes
 
#GLOBAL
pacman=cdll.LoadLibrary("libpacman.so")
CFG_FILE = "/etc/pacman-g2.conf"
 
#for print debug messages
debug=1
 
 
#some class for pacman-g2
class PM_LIST(Structure):
  pass
PM_LIST._fields_ = [
        ("data", ctypes.c_void_p),
        ("prev", POINTER(PM_LIST)),
        ("next", POINTER(PM_LIST)),
        ("last", POINTER(PM_LIST))]     
class PM_DB(Structure):
  pass
PM_DB._fields_ = [
        ("path", ctypes.c_char_p),
        ("treename", ctypes.c_char * 255),
        ("handle", ctypes.c_void_p),
        ("pkgcache", POINTER(PM_LIST)),
        ("grpcache", POINTER(PM_LIST)),
        ("handle", POINTER(PM_LIST)),
        ("servers", ctypes.c_char),
        ("lastupdate", ctypes.c_char * 16)]
 
def _db_cb (section,db):
  print_debug("passe")
  print_debug(db)
  return
 
def pacman_init():
  pacman.pacman_release()
  if pacman.pacman_initialize("/") == -1:
    print "Can't initialise pacman-g2"
    sys.exit(0) 
 
def pacman_init_database():
  print_debug("init database")
  pacman_cb_db_register = CFUNCTYPE(ctypes.c_void_p, ctypes.c_char_p, POINTER(PM_DB))
  print_debug("pacman_parse_config")
  pacman.pacman_parse_config.argtypes = [ctypes.c_char_p,pacman_cb_db_register,ctypes.c_char_p]
  pacman.pacman_parse_config.restype = ctypes.c_int
  pacman.pacman_parse_config(CFG_FILE,pacman_cb_db_register(_db_cb),'')
  print_debug("pacman_parse_config fini")
 
def main():
  pacman_init()
  pacman_init_database()
 
 
def help():
  print "help :"
  print "--search Package"
  sys.exit(0)
 
 
def print_debug(textConsole):
  if debug <> 1:
    return
  print "DEBUG : "+textConsole
 
def _db_cb(section , db):
  print db
 
#start main program
main()

Mais en sorti :

Code:

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DEBUG : init database
DEBUG : pacman_parse_config
<__main__.LP_PM_DB object at 0xb733ef5c>
DEBUG : pacman_parse_config fini

Voici la structure C de PM_DB :

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/* Database */
typedef struct __pmdb_t {
	char *path;
	char treename[PATH_MAX];
	void *handle;
	pmlist_t *pkgcache;
	pmlist_t *grpcache;
	pmlist_t *servers;
	char lastupdate[16];
} pmdb_t;

Resolu :

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#!/usr/bin/env python
 
import os, tempfile, shutil, sys
from ctypes import *
import ctypes
 
#GLOBAL
pacman=cdll.LoadLibrary("libpacman.so")
CFG_FILE = "/etc/pacman-g2.conf"
 
#for print debug messages
debug=1
 
 
#some class for pacman-g2
class PM_LIST(Structure):
  pass
PM_LIST._fields_ = [
        ("data", ctypes.c_void_p),
        ("prev", POINTER(PM_LIST)),
        ("next", POINTER(PM_LIST)),
        ("last", POINTER(PM_LIST))]     
class PM_DB(Structure):
  pass
PM_DB._fields_ = [
        ("path", ctypes.c_char_p),
        ("treename", ctypes.c_char * 255),
        ("handle", ctypes.c_void_p),
        ("pkgcache", POINTER(PM_LIST)),
        ("grpcache", POINTER(PM_LIST)),
        ("handle", POINTER(PM_LIST)),
        ("servers", ctypes.c_char),
        ("lastupdate", ctypes.c_char * 16)]
 
def _db_cb (section,db):
  print_debug("passe")
  print_debug(section)
  return
 
def pacman_init():
  print_debug("init database")
  pacman.pacman_release()
  if pacman.pacman_initialize("/") == -1:
    print "Can't initialise pacman-g2"
    sys.exit(0) 
 
pacman_cb_db_register = CFUNCTYPE(ctypes.c_void_p, ctypes.c_char_p, POINTER(PM_DB))
 
def pacman_init_database():
  print_debug("pacman_parse_config")
  pacman.pacman_parse_config.argtypes = [ctypes.c_char_p,pacman_cb_db_register,ctypes.c_char_p]
  pacman.pacman_parse_config.restype = ctypes.c_int
  pacman.pacman_parse_config(CFG_FILE,pacman_cb_db_register(_db_cb),'')
 
def main():
  pacman_init()
  pacman_init_database()
 
 
def help():
  print "help :"
  print "--search Package"
  sys.exit(0)
 
def print_debug(textConsole):
  if debug <> 1:
    return
  print "DEBUG : "+textConsole
 
#start main program
main()