plpython.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

					 errmsg("plpython functions cannot return tuples yet")));
			else
				PLy_output_datum_func(&proc->result, rvTypeTup);

			ReleaseSysCache(rvTypeTup);
		}
		else
		{
			/*
			 * input/output conversion for trigger tuples.	use the result
			 * TypeInfo variable to store the tuple conversion info.
			 */
			TriggerData *tdata = (TriggerData *) fcinfo->context;

			PLy_input_tuple_funcs(&(proc->result), tdata->tg_relation->rd_att);
			PLy_output_tuple_funcs(&(proc->result), tdata->tg_relation->rd_att);
		}

		/*
		 * now get information required for input conversion of the procedure's
		 * arguments.
		 */
		proc->nargs = fcinfo->nargs;
		for (i = 0; i < fcinfo->nargs; i++)
		{
			HeapTuple	argTypeTup;
			Form_pg_type argTypeStruct;

			argTypeTup = SearchSysCache(TYPEOID,
						 ObjectIdGetDatum(procStruct->proargtypes.values[i]),
										0, 0, 0);
			if (!HeapTupleIsValid(argTypeTup))
				elog(ERROR, "cache lookup failed for type %u",
					 procStruct->proargtypes.values[i]);
			argTypeStruct = (Form_pg_type) GETSTRUCT(argTypeTup);

			/* Disallow pseudotype argument */
			if (argTypeStruct->typtype == 'p')
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("plpython functions cannot take type %s",
						format_type_be(procStruct->proargtypes.values[i]))));

			if (argTypeStruct->typtype != 'c')
				PLy_input_datum_func(&(proc->args[i]),
									 procStruct->proargtypes.values[i],
									 argTypeTup);
			else
				proc->args[i].is_rowtype = 2;	/* still need to set I/O funcs */

			ReleaseSysCache(argTypeTup);
		}


		/*
		 * get the text of the function.
		 */
		prosrcdatum = SysCacheGetAttr(PROCOID, procTup,
									  Anum_pg_proc_prosrc, &isnull);
		if (isnull)
			elog(ERROR, "null prosrc");
		procSource = DatumGetCString(DirectFunctionCall1(textout,
														 prosrcdatum));

		PLy_procedure_compile(proc, procSource);

		pfree(procSource);

		proc->me = PyCObject_FromVoidPtr(proc, NULL);
		PyDict_SetItemString(PLy_procedure_cache, key, proc->me);
	}
	PG_CATCH();
	{
		PLy_procedure_delete(proc);
		if (procSource)
			pfree(procSource);

		PG_RE_THROW();
	}
	PG_END_TRY();

	return proc;
}

static void
PLy_procedure_compile(PLyProcedure * proc, const char *src)
{
	PyObject   *crv = NULL;
	char	   *msrc;

	proc->globals = PyDict_Copy(PLy_interp_globals);

	/*
	 * SD is private preserved data between calls GD is global data shared by
	 * all functions
	 */
	proc->statics = PyDict_New();
	PyDict_SetItemString(proc->globals, "SD", proc->statics);

	/*
	 * insert the function code into the interpreter
	 */
	msrc = PLy_procedure_munge_source(proc->pyname, src);
	crv = PyRun_String(msrc, Py_file_input, proc->globals, NULL);
	free(msrc);

	if ((crv != NULL) && (!PyErr_Occurred()))
	{
		int			clen;
		char		call[NAMEDATALEN + 256];

		Py_DECREF(crv);

		/*
		 * compile a call to the function
		 */
		clen = snprintf(call, sizeof(call), "%s()", proc->pyname);
		if ((clen < 0) || (clen >= sizeof(call)))
			elog(ERROR, "string would overflow buffer");
		proc->code = Py_CompileString(call, "<string>", Py_eval_input);
		if ((proc->code != NULL) && (!PyErr_Occurred()))
			return;
	}
	else
		Py_XDECREF(crv);

	PLy_elog(ERROR, "could not compile function \"%s\"", proc->proname);
}

static char *
PLy_procedure_munge_source(const char *name, const char *src)
{
	char	   *mrc,
			   *mp;
	const char *sp;
	size_t		mlen,
				plen;

	/*
	 * room for function source and the def statement
	 */
	mlen = (strlen(src) * 2) + strlen(name) + 16;

	mrc = PLy_malloc(mlen);
	plen = snprintf(mrc, mlen, "def %s():\n\t", name);
	Assert(plen >= 0 && plen < mlen);

	sp = src;
	mp = mrc + plen;

	while (*sp != '\0')
	{
		if (*sp == '\r' && *(sp + 1) == '\n')
			sp++;

		if (*sp == '\n' || *sp == '\r')
		{
			*mp++ = '\n';
			*mp++ = '\t';
			sp++;
		}
		else
			*mp++ = *sp++;
	}
	*mp++ = '\n';
	*mp++ = '\n';
	*mp = '\0';

	if (mp > (mrc + mlen))
		elog(FATAL, "buffer overrun in PLy_munge_source");

	return mrc;
}

static void
PLy_procedure_delete(PLyProcedure * proc)
{
	int			i;

	Py_XDECREF(proc->code);
	Py_XDECREF(proc->statics);
	Py_XDECREF(proc->globals);
	Py_XDECREF(proc->me);
	if (proc->proname)
		PLy_free(proc->proname);
	if (proc->pyname)
		PLy_free(proc->pyname);
	for (i = 0; i < proc->nargs; i++)
		if (proc->args[i].is_rowtype == 1)
		{
			if (proc->args[i].in.r.atts)
				PLy_free(proc->args[i].in.r.atts);
			if (proc->args[i].out.r.atts)
				PLy_free(proc->args[i].out.r.atts);
		}
}

/* conversion functions.  remember output from python is
 * input to postgresql, and vis versa.
 */
static void
PLy_input_tuple_funcs(PLyTypeInfo * arg, TupleDesc desc)
{
	int			i;

	if (arg->is_rowtype == 0)
		elog(ERROR, "PLyTypeInfo struct is initialized for a Datum");

	arg->is_rowtype = 1;
	arg->in.r.natts = desc->natts;
	arg->in.r.atts = malloc(desc->natts * sizeof(PLyDatumToOb));

	for (i = 0; i < desc->natts; i++)
	{
		HeapTuple	typeTup;

		if (desc->attrs[i]->attisdropped)
			continue;

		typeTup = SearchSysCache(TYPEOID,
								 ObjectIdGetDatum(desc->attrs[i]->atttypid),
								 0, 0, 0);
		if (!HeapTupleIsValid(typeTup))
			elog(ERROR, "cache lookup failed for type %u",
				 desc->attrs[i]->atttypid);

		PLy_input_datum_func2(&(arg->in.r.atts[i]),
							  desc->attrs[i]->atttypid,
							  typeTup);

		ReleaseSysCache(typeTup);
	}
}

static void
PLy_output_tuple_funcs(PLyTypeInfo * arg, TupleDesc desc)
{
	int			i;

	if (arg->is_rowtype == 0)
		elog(ERROR, "PLyTypeInfo struct is initialized for a Datum");

	arg->is_rowtype = 1;
	arg->out.r.natts = desc->natts;
	arg->out.r.atts = malloc(desc->natts * sizeof(PLyDatumToOb));

	for (i = 0; i < desc->natts; i++)
	{
		HeapTuple	typeTup;

		if (desc->attrs[i]->attisdropped)
			continue;

		typeTup = SearchSysCache(TYPEOID,
								 ObjectIdGetDatum(desc->attrs[i]->atttypid),
								 0, 0, 0);
		if (!HeapTupleIsValid(typeTup))
			elog(ERROR, "cache lookup failed for type %u",
				 desc->attrs[i]->atttypid);

		PLy_output_datum_func2(&(arg->out.r.atts[i]), typeTup);

		ReleaseSysCache(typeTup);
	}
}

static void
PLy_output_datum_func(PLyTypeInfo * arg, HeapTuple typeTup)
{
	if (arg->is_rowtype > 0)
		elog(ERROR, "PLyTypeInfo struct is initialized for a Tuple");
	arg->is_rowtype = 0;
	PLy_output_datum_func2(&(arg->out.d), typeTup);
}

static void
PLy_output_datum_func2(PLyObToDatum * arg, HeapTuple typeTup)
{
	Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

	perm_fmgr_info(typeStruct->typinput, &arg->typfunc);
	arg->typioparam = getTypeIOParam(typeTup);
	arg->typbyval = typeStruct->typbyval;
}

static void
PLy_input_datum_func(PLyTypeInfo * arg, Oid typeOid, HeapTuple typeTup)
{
	if (arg->is_rowtype > 0)
		elog(ERROR, "PLyTypeInfo struct is initialized for Tuple");
	arg->is_rowtype = 0;
	PLy_input_datum_func2(&(arg->in.d), typeOid, typeTup);
}

static void
PLy_input_datum_func2(PLyDatumToOb * arg, Oid typeOid, HeapTuple typeTup)
{
	Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

	/* Get the type's conversion information */
	perm_fmgr_info(typeStruct->typoutput, &arg->typfunc);
	arg->typioparam = getTypeIOParam(typeTup);
	arg->typbyval = typeStruct->typbyval;

	/* Determine which kind of Python object we will convert to */
	switch (typeOid)
	{
		case BOOLOID:
			arg->func = PLyBool_FromString;
			break;
		case FLOAT4OID:
		case FLOAT8OID:
		case NUMERICOID:
			arg->func = PLyFloat_FromString;
			break;
		case INT2OID:
		case INT4OID:
			arg->func = PLyInt_FromString;
			break;
		case INT8OID:
			arg->func = PLyLong_FromString;
			break;
		default:
			arg->func = PLyString_FromString;
			break;
	}
}

static void
PLy_typeinfo_init(PLyTypeInfo * arg)
{
	arg->is_rowtype = -1;
	arg->in.r.natts = arg->out.r.natts = 0;
	arg->in.r.atts = NULL;
	arg->out.r.atts = NULL;
}

static void
PLy_typeinfo_dealloc(PLyTypeInfo * arg)
{
	if (arg->is_rowtype == 1)
	{
		if (arg->in.r.atts)
			PLy_free(arg->in.r.atts);
		if (arg->out.r.atts)
			PLy_free(arg->out.r.atts);
	}
}

/* assumes that a bool is always returned as a 't' or 'f'
 */
static PyObject *
PLyBool_FromString(const char *src)
{
	if (src[0] == 't')
		return PyInt_FromLong(1);
	return PyInt_FromLong(0);
}

static PyObject *
PLyFloat_FromString(const char *src)
{
	double		v;
	char	   *eptr;

	errno = 0;
	v = strtod(src, &eptr);
	if ((*eptr != '\0') || (errno))
		return NULL;
	return PyFloat_FromDouble(v);
}

static PyObject *
PLyInt_FromString(const char *src)
{
	long		v;
	char	   *eptr;

	errno = 0;
	v = strtol(src, &eptr, 0);
	if ((*eptr != '\0') || (errno))
		return NULL;
	return PyInt_FromLong(v);
}

static PyObject *
PLyLong_FromString(const char *src)
{
	return PyLong_FromString((char *) src, NULL, 0);
}

static PyObject *
PLyString_FromString(const char *src)
{
	return PyString_FromString(src);
}

static PyObject *
PLyDict_FromTuple(PLyTypeInfo * info, HeapTuple tuple, TupleDesc desc)
{
	PyObject   *volatile dict;
	int			i;

	if (info->is_rowtype != 1)
		elog(ERROR, "PLyTypeInfo structure describes a datum");

	dict = PyDict_New();
	if (dict == NULL)
		PLy_elog(ERROR, "could not create tuple dictionary");

	PG_TRY();
	{
		for (i = 0; i < info->in.r.natts; i++)
		{
			char	   *key,
					   *vsrc;
			Datum		vattr,
						vdat;
			bool		is_null;
			PyObject   *value;

			if (desc->attrs[i]->attisdropped)
				continue;

			key = NameStr(desc->attrs[i]->attname);
			vattr = heap_getattr(tuple, (i + 1), desc, &is_null);

			if ((is_null) || (info->in.r.atts[i].func == NULL))
				PyDict_SetItemString(dict, key, Py_None);
			else
			{
				vdat = FunctionCall3(&info->in.r.atts[i].typfunc,
									 vattr,
							 ObjectIdGetDatum(info->in.r.atts[i].typioparam),
								   Int32GetDatum(desc->attrs[i]->atttypmod));
				vsrc = DatumGetCString(vdat);

				/*
				 * no exceptions allowed
				 */
				value = info->in.r.atts[i].func(vsrc);
				pfree(vsrc);
				PyDict_SetItemString(dict, key, value);
				Py_DECREF(value);
			}
		}
	}
	PG_CATCH();
	{
		Py_DECREF(dict);
		PG_RE_THROW();
	}
	PG_END_TRY();

	return dict;
}

/* initialization, some python variables function declared here
 */

/* interface to postgresql elog
 */
static PyObject *PLy_debug(PyObject *, PyObject *);
static PyObject *PLy_log(PyObject *, PyObject *);
static PyObject *PLy_info(PyObject *, PyObject *);
static PyObject *PLy_notice(PyObject *, PyObject *);
static PyObject *PLy_warning(PyObject *, PyObject *);
static PyObject *PLy_error(PyObject *, PyObject *);
static PyObject *PLy_fatal(PyObject *, PyObject *);

/* PLyPlanObject, PLyResultObject and SPI interface
 */
#define is_PLyPlanObject(x) ((x)->ob_type == &PLy_PlanType)
static PyObject *PLy_plan_new(void);
static void PLy_plan_dealloc(PyObject *);
static PyObject *PLy_plan_getattr(PyObject *, char *);
static PyObject *PLy_plan_status(PyObject *, PyObject *);

static PyObject *PLy_result_new(void);
static void PLy_result_dealloc(PyObject *);
static PyObject *PLy_result_getattr(PyObject *, char *);
static PyObject *PLy_result_nrows(PyObject *, PyObject *);
static PyObject *PLy_result_status(PyObject *, PyObject *);
static int	PLy_result_length(PyObject *);
static PyObject *PLy_result_item(PyObject *, int);
static PyObject *PLy_result_slice(PyObject *, int, int);
static int	PLy_result_ass_item(PyObject *, int, PyObject *);
static int	PLy_result_ass_slice(PyObject *, int, int, PyObject *);


static PyObject *PLy_spi_prepare(PyObject *, PyObject *);
static PyObject *PLy_spi_execute(PyObject *, PyObject *);
static PyObject *PLy_spi_execute_query(char *query, long limit);
static PyObject *PLy_spi_execute_plan(PyObject *, PyObject *, long);
static PyObject *PLy_spi_execute_fetch_result(SPITupleTable *, int, int);


static PyTypeObject PLy_PlanType = {
	PyObject_HEAD_INIT(NULL)
	0,							/* ob_size */
	"PLyPlan",					/* tp_name */
	sizeof(PLyPlanObject),		/* tp_size */
	0,							/* tp_itemsize */

	/*
	 * methods
	 */
	(destructor) PLy_plan_dealloc,		/* tp_dealloc */
	0,							/* tp_print */
	(getattrfunc) PLy_plan_getattr,		/* tp_getattr */
	0,							/* tp_setattr */
	0,							/* tp_compare */
	0,							/* tp_repr */
	0,							/* tp_as_number */
	0,							/* tp_as_sequence */
	0,							/* tp_as_mapping */
	0,							/* tp_hash */
	0,							/* tp_call */
	0,							/* tp_str */
	0,							/* tp_getattro */
	0,							/* tp_setattro */
	0,							/* tp_as_buffer */
	0,							/* tp_xxx4 */
	PLy_plan_doc,				/* tp_doc */
};

static PyMethodDef PLy_plan_methods[] = {
	{"status", PLy_plan_status, METH_VARARGS, NULL},
	{NULL, NULL, 0, NULL}
};