python扩展模块的C API

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  1. ==> sonmodule.h <==
  2. typedef struct {
  3.   PyObject_HEAD
  4.   PyObject *str;
  5.   int num;
  6. } Son;
  7.  
  8. #define MAKE_SON_NEW(self, type, rt_error)	
  9.   (self) = (Son *)(type)->tp_alloc((type), 0);	
  10.   if ((self) == rt_error) { return rt_error; }	
  11. 						
  12.   (self)->str = PyString_FromString("");	
  13.   if ((self)->str == rt_error) {		
  14.     Py_DECREF((self));				
  15.     return rt_error;				
  16.   }						
  17. 						
  18.   (self)->num = 0
  19.  
  20. #ifdef __SON_MODULE
  21. /* ---------- inclue form sonmodule.c ---------- */
  22. static PyTypeObject SonType;
  23.  
  24. #else
  25. /* ---------- inclue form othere module to use api ---------- */
  26. /* store all api here */
  27. void **Son_API;
  28. /* set alias for easy call */
  29. #define SonType (*(PyTypeObject *)Son_API[0])
  30. #define Son_info (*(PyObject *(*) (Son *))Son_API[1])
  31.  
  32. static int _import_son(void)
  33. {
  34.   PyObject *son = PyImport_ImportModule("son");
  35.   PyObject *c_api = NULL;
  36.   if (son == NULL){ return -1; }
  37.  
  38.   /* load c api */
  39.   c_api = PyObject_GetAttrString(son, "_Son_API");
  40.   if (c_api == NULL) {Py_DECREF(son); return -1;}
  41.   if (PyCObject_Check(c_api)) {
  42.     Son_API = (void **)PyCObject_AsVoidPtr(c_api);
  43.   }
  44.   Py_DECREF(c_api);
  45.   Py_DECREF(son);
  46.   if (Son_API == NULL) return -1;
  47.  
  48.   return 0;
  49. }
  50.  
  51. #define import_son()				
  52.   {						
  53.     if (_import_son() < 0) {			
  54.       PyErr_Print();				
  55.       PyErr_SetString( PyExc_ImportError,	
  56. 		       "son failed to import");	
  57.       return;					
  58.     }						
  59.   }
  60.  
  61. #endif
  62. /* __SONMODULE */
  63.  
  64. ==> sonmodule.c <==
  65. #include <Python.h>
  66. #include "structmember.h"
  67.  
  68. #define __SON_MODULE
  69. #include "sonmodule.h"
  70. #undef __SON_MODULE
  71.  
  72. static void
  73. Son_dealloc(Son* self)
  74. {
  75.   Py_XDECREF(self->str);
  76.   self->ob_type->tp_free((PyObject*)self);
  77. }
  78.  
  79. static PyObject *
  80. Son_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
  81. {
  82.   Son *self;
  83.   MAKE_SON_NEW(self, type, NULL);
  84.   return (PyObject *)self;
  85. }
  86.  
  87. static int
  88. Son_init(Son *self, PyObject *args, PyObject *kwds)
  89. {
  90.   PyObject *str=NULL, *tmp;
  91.  
  92.   static char *kwlist[] = {"str", "num", NULL};
  93.  
  94.   if (! PyArg_ParseTupleAndKeywords(args, kwds, "|Si", kwlist, 
  95. 				    &str,
  96. 				    &self->num)){
  97.     return -1; 
  98.   }
  99.  
  100.   if (str) {
  101.     tmp = self->str;
  102.     Py_INCREF(str);
  103.     self->str = str;
  104.     Py_DECREF(tmp);
  105.   }
  106.  
  107.   return 0;
  108. }
  109.  
  110. static PyMemberDef Son_members[] = {
  111.   {"num", T_INT, offsetof(Son, num), 0, "Sone num"},
  112.   {NULL}  /* Sentinel */
  113. };
  114.  
  115. static PyObject *
  116. Son_getstr(Son *self, void *closure)
  117. {
  118.   Py_INCREF(self->str);
  119.   return self->str;
  120. }
  121.  
  122. static int
  123. Son_setstr(Son *self, PyObject *value, void *closure)
  124. {
  125.   if (value == NULL) {
  126.     PyErr_SetString(PyExc_TypeError, "Cannot delete the str attribute");
  127.     return -1;
  128.   }
  129.  
  130.   if (! PyString_Check(value)) {
  131.     PyErr_SetString(PyExc_TypeError, 
  132.                     "The str attribute value must be a string");
  133.     return -1;
  134.   }
  135.  
  136.   Py_DECREF(self->str);
  137.   Py_INCREF(value);
  138.   self->str = value;    
  139.  
  140.   return 0;
  141. }
  142.  
  143. static PyGetSetDef Son_getseters[] = {
  144.   {"str", (getter)Son_getstr, (setter)Son_setstr, "str", NULL},
  145.   {NULL}  /* Sentinel */
  146. };
  147.  
  148. static PyObject *
  149. Son_info(Son *self)
  150. {
  151.   PyObject *dic = PyDict_New();
  152.   if (dic == NULL) {
  153.     printf("creating dict failed
");
  154.     return NULL;
  155.   }
  156.   Py_INCREF(self->str);
  157.   PyDict_SetItemString(dic, "str", self->str);
  158.   PyDict_SetItemString(dic, "num", PyLong_FromLong( self->num ));
  159.   return dic;
  160. }
  161.  
  162. static PyMethodDef Son_methods[] = {
  163.   {"info", (PyCFunction)Son_info, METH_NOARGS, "return info dic"},
  164.   {NULL}  /* Sentinel */
  165. };
  166.  
  167. static PyTypeObject SonType = {
  168.   PyObject_HEAD_INIT(NULL)
  169.   0,				/*ob_size*/
  170.   "son.Son",			/*tp_name*/
  171.   sizeof(Son),			/*tp_basicsize*/
  172.   0,				/*tp_itemsize*/
  173.   (destructor)Son_dealloc,	/*tp_dealloc*/
  174.   0,				/*tp_print*/
  175.   0,				/*tp_getattr*/
  176.   0,				/*tp_setattr*/
  177.   0,				/*tp_compare*/
  178.   0,				/*tp_repr*/
  179.   0,				/*tp_as_number*/
  180.   0,				/*tp_as_sequence*/
  181.   0,				/*tp_as_mapping*/
  182.   0,				/*tp_hash */
  183.   0,				/*tp_call*/
  184.   0,				/*tp_str*/
  185.   0,				/*tp_getattro*/
  186.   0,				/*tp_setattro*/
  187.   0,				/*tp_as_buffer*/
  188.   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,	/*tp_flags*/
  189.   "Son objects",		/* tp_doc */
  190.   0,				/* tp_traverse */
  191.   0,				/* tp_clear */
  192.   0,				/* tp_richcompare */
  193.   0,				/* tp_weaklistoffset */
  194.   0,				/* tp_iter */
  195.   0,				/* tp_iternext */
  196.   Son_methods,			/* tp_methods */
  197.   Son_members,			/* tp_members */
  198.   Son_getseters,		/* tp_getset */
  199.   0,				/* tp_base */
  200.   0,				/* tp_dict */
  201.   0,				/* tp_descr_get */
  202.   0,				/* tp_descr_set */
  203.   0,				/* tp_dictoffset */
  204.   (initproc)Son_init,		/* tp_init */
  205.   0,				/* tp_alloc */
  206.   Son_new,			/* tp_new */
  207. };
  208.  
  209. static PyMethodDef module_methods[] = {
  210.   {NULL}  /* Sentinel */
  211. };
  212.  
  213. /* ---------- insert object into api array ---------- */
  214. void *Son_API[] = {
  215.   (void *) &SonType,
  216.   (void *) Son_info,
  217. };
  218.  
  219. #ifndef PyMODINIT_FUNC	/* declarations for DLL import/export */
  220. #define PyMODINIT_FUNC void
  221. #endif
  222. PyMODINIT_FUNC
  223. initson(void) 
  224. {
  225.   PyObject *m, *d;
  226.   PyObject *c_api;
  227.   if (PyType_Ready(&SonType) < 0){ return; }
  228.  
  229.   m = Py_InitModule3("son", module_methods,
  230. 		     "Son Class");
  231.  
  232.   if (m == NULL){ goto err; }
  233.  
  234.   Py_INCREF(&SonType);
  235.   PyModule_AddObject(m, "Son", (PyObject *)&SonType);
  236.  
  237.   /* ----- set api to module ----- */
  238.   d = PyModule_GetDict(m);
  239.   if (!d){ goto err; }
  240.  
  241.   c_api = PyCObject_FromVoidPtr((void *)Son_API, NULL);
  242.   if (c_api == NULL){ goto err; }
  243.   PyDict_SetItemString(d, "_Son_API", c_api);
  244.   Py_DECREF(c_api);
  245.  
  246.   return;
  247.  
  248.  err:
  249.   if (!PyErr_Occurred()) {
  250.     PyErr_SetString(PyExc_RuntimeError,
  251. 		    "cannot load son module.");
  252.   }
  253.   return;
  254. }
  255.  
  256. ==> fathermodule.c <==
  257. #include <Python.h>
  258. #include "structmember.h"
  259.  
  260. #include "sonmodule.h"
  261.  
  262. typedef struct {
  263.   PyObject_HEAD
  264.   Son *son;
  265. } Father;
  266.  
  267. static void
  268. Father_dealloc(Father* self)
  269. {
  270.   Py_XDECREF(self->son);
  271.   self->ob_type->tp_free((PyObject*)self);
  272. }
  273.  
  274. static PyObject *
  275. Father_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
  276. {
  277.   Father *self;
  278.  
  279.   self = (Father *)type->tp_alloc(type, 0);
  280.   if (self == NULL) { return NULL; }
  281.  
  282.   MAKE_SON_NEW(self->son, &SonType, NULL);
  283.  
  284.   return (PyObject *)self;
  285. }
  286.  
  287. static int
  288. Father_init(Father *self, PyObject *args, PyObject *kwds)
  289. {
  290.   return 0;
  291. }
  292.  
  293. static PyMemberDef Father_members[] = {
  294.   {NULL}  /* Sentinel */
  295. };
  296.  
  297. static PyObject *
  298. Father_getson(Father *self, void *closure)
  299. {
  300.   Py_INCREF(self->son);
  301.   return (PyObject *)self->son;
  302. }
  303.  
  304. static int
  305. Father_setson(Father *self, PyObject *value, void *closure)
  306. {
  307.   if (value == NULL) {
  308.     PyErr_SetString(PyExc_TypeError, "Cannot delete the son attribute");
  309.     return -1;
  310.   }
  311.  
  312.   if (! PyObject_TypeCheck(value, &SonType)) {/* SonType is from Son_API! */
  313.     PyErr_SetString(PyExc_TypeError, 
  314.                     "The str attribute value must be a Son");
  315.     return -1;
  316.   }
  317.  
  318.   Py_DECREF(self->son);
  319.   Py_INCREF(value);
  320.   self->son = (Son *)value;
  321.  
  322.   return 0;
  323. }
  324.  
  325. static PyGetSetDef Father_getseters[] = {
  326.   {"son", (getter)Father_getson, (setter)Father_setson, "son", NULL},
  327.   {NULL}  /* Sentinel */
  328. };
  329.  
  330. static PyObject *
  331. Father_info(Father *self)
  332. {
  333.   PyObject *dic = PyDict_New();
  334.   if (dic == NULL) {
  335.     printf("creating dict failed
");
  336.     return NULL;
  337.   }
  338.   PyDict_SetItemString(dic, "son",
  339. 		       Son_info(self->son));/* Son_info is from Son_API! */
  340.   return dic;
  341. }
  342.  
  343. static PyMethodDef Father_methods[] = {
  344.   {"info", (PyCFunction)Father_info, METH_NOARGS, "return info dic"},
  345.   {NULL}  /* Sentinel */
  346. };
  347.  
  348. static PyTypeObject FatherType = {
  349.     PyObject_HEAD_INIT(NULL)
  350.     0,                         /*ob_size*/
  351.     "father.Father",             /*tp_name*/
  352.     sizeof(Father),             /*tp_basicsize*/
  353.     0,                         /*tp_itemsize*/
  354.     (destructor)Father_dealloc, /*tp_dealloc*/
  355.     0,                         /*tp_print*/
  356.     0,                         /*tp_getattr*/
  357.     0,                         /*tp_setattr*/
  358.     0,                         /*tp_compare*/
  359.     0,                         /*tp_repr*/
  360.     0,                         /*tp_as_number*/
  361.     0,                         /*tp_as_sequence*/
  362.     0,                         /*tp_as_mapping*/
  363.     0,                         /*tp_hash */
  364.     0,                         /*tp_call*/
  365.     0,                         /*tp_str*/
  366.     0,                         /*tp_getattro*/
  367.     0,                         /*tp_setattro*/
  368.     0,                         /*tp_as_buffer*/
  369.     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
  370.     "Father objects",           /* tp_doc */
  371.     0,		               /* tp_traverse */
  372.     0,		               /* tp_clear */
  373.     0,		               /* tp_richcompare */
  374.     0,		               /* tp_weaklistoffset */
  375.     0,		               /* tp_iter */
  376.     0,		               /* tp_iternext */
  377.     Father_methods,             /* tp_methods */
  378.     Father_members,             /* tp_members */
  379.     Father_getseters,           /* tp_getset */
  380.     0,                         /* tp_base */
  381.     0,                         /* tp_dict */
  382.     0,                         /* tp_descr_get */
  383.     0,                         /* tp_descr_set */
  384.     0,                         /* tp_dictoffset */
  385.     (initproc)Father_init,      /* tp_init */
  386.     0,                         /* tp_alloc */
  387.     Father_new,                 /* tp_new */
  388. };
  389.  
  390. static PyMethodDef module_methods[] = {
  391.     {NULL}  /* Sentinel */
  392. };
  393.  
  394. #ifndef PyMODINIT_FUNC	/* declarations for DLL import/export */
  395. #define PyMODINIT_FUNC void
  396. #endif
  397. PyMODINIT_FUNC
  398. initfather(void) 
  399. {
  400.   PyObject* m;
  401.   if (PyType_Ready(&FatherType) < 0){ return; }
  402.  
  403.   m = Py_InitModule3("father", module_methods,
  404. 		     "Father Class");
  405.  
  406.   if (m == NULL){ return; }
  407.  
  408.   Py_INCREF(&FatherType);
  409.   PyModule_AddObject(m, "Father", (PyObject *)&FatherType);
  410.  
  411.   import_son();
  412. }
  413.  
  414. ==> setup.py <==
  415. # python setup.py build build_ext --inplace
  416. import sys
  417. import os
  418. from distutils.core import setup, Extension
  419.  
  420. son_module = Extension(
  421.     'son',
  422.     define_macros = [],
  423.     include_dirs = [],
  424.     libraries = [],
  425.     library_dirs = [],
  426.     extra_compile_args = [],
  427.     sources = ['sonmodule.c'])
  428.  
  429. father_module = Extension(
  430.     'father',
  431.     define_macros = [],
  432.     include_dirs = [],
  433.     libraries = [],
  434.     library_dirs = [],
  435.     extra_compile_args = [],
  436.     sources = ['fathermodule.c'])
  437.  
  438. setup(
  439.     name = 'storage',
  440.     version = '1.0',
  441.     description = '',
  442.     ext_modules = [son_module, father_module] )
  443.  
  444. ==> test.txt <==
  445. >>> import son
  446. >>> sn = son.Son()
  447. >>> import father
  448. >>> fr = father.Father()
  449. >>> sn.num = 12
  450. >>> sn.str = "son str"
  451. >>> sn.info()
  452. {'num': 12L, 'str': 'son str'}
  453. >>> fr.son
  454. <son.Son object at 0xb7cd5070>
  455. >>> fr.son.info()
  456. {'num': 0L, 'str': ''}
  457. >>> fr.info()
  458. {'son': {'num': 0L, 'str': ''}}
  459. >>> fr.son = sn
  460. >>> fr.info()
  461. {'son': {'num': 12L, 'str': 'son str'}}

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