plpython.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

			}
			else
			{
				modvalues[i] = (Datum) 0;
				modnulls[i] = 'n';
			}

			Py_DECREF(plval);
			plval = NULL;
		}

		rtup = SPI_modifytuple(tdata->tg_relation, otup, natts,
							   modattrs, modvalues, modnulls);
		if (rtup == NULL)
			elog(ERROR, "SPI_modifytuple failed -- error %d", SPI_result);
	}
	PG_CATCH();
	{
		Py_XDECREF(plntup);
		Py_XDECREF(plkeys);
		Py_XDECREF(plval);
		Py_XDECREF(plstr);

		if (modnulls)
			pfree(modnulls);
		if (modvalues)
			pfree(modvalues);
		if (modattrs)
			pfree(modattrs);

		PG_RE_THROW();
	}
	PG_END_TRY();

	Py_DECREF(plntup);
	Py_DECREF(plkeys);

	pfree(modattrs);
	pfree(modvalues);
	pfree(modnulls);

	return rtup;
}

static PyObject *
PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure * proc, HeapTuple *rv)
{
	TriggerData *tdata = (TriggerData *) fcinfo->context;
	PyObject   *pltname,
			   *pltevent,
			   *pltwhen,
			   *pltlevel,
			   *pltrelid;
	PyObject   *pltargs,
			   *pytnew,
			   *pytold;
	PyObject   *volatile pltdata = NULL;
	char	   *stroid;

	PG_TRY();
	{
		pltdata = PyDict_New();
		if (!pltdata)
			PLy_elog(ERROR, "could not build arguments for trigger procedure");

		pltname = PyString_FromString(tdata->tg_trigger->tgname);
		PyDict_SetItemString(pltdata, "name", pltname);
		Py_DECREF(pltname);

		stroid = DatumGetCString(DirectFunctionCall1(oidout,
							   ObjectIdGetDatum(tdata->tg_relation->rd_id)));
		pltrelid = PyString_FromString(stroid);
		PyDict_SetItemString(pltdata, "relid", pltrelid);
		Py_DECREF(pltrelid);
		pfree(stroid);

		if (TRIGGER_FIRED_BEFORE(tdata->tg_event))
			pltwhen = PyString_FromString("BEFORE");
		else if (TRIGGER_FIRED_AFTER(tdata->tg_event))
			pltwhen = PyString_FromString("AFTER");
		else
		{
			elog(ERROR, "unrecognized WHEN tg_event: %u", tdata->tg_event);
			pltwhen = NULL;		/* keep compiler quiet */
		}
		PyDict_SetItemString(pltdata, "when", pltwhen);
		Py_DECREF(pltwhen);

		if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
		{
			pltlevel = PyString_FromString("ROW");
			PyDict_SetItemString(pltdata, "level", pltlevel);
			Py_DECREF(pltlevel);

			if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
			{
				pltevent = PyString_FromString("INSERT");

				PyDict_SetItemString(pltdata, "old", Py_None);
				pytnew = PLyDict_FromTuple(&(proc->result), tdata->tg_trigtuple,
										   tdata->tg_relation->rd_att);
				PyDict_SetItemString(pltdata, "new", pytnew);
				Py_DECREF(pytnew);
				*rv = tdata->tg_trigtuple;
			}
			else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
			{
				pltevent = PyString_FromString("DELETE");

				PyDict_SetItemString(pltdata, "new", Py_None);
				pytold = PLyDict_FromTuple(&(proc->result), tdata->tg_trigtuple,
										   tdata->tg_relation->rd_att);
				PyDict_SetItemString(pltdata, "old", pytold);
				Py_DECREF(pytold);
				*rv = tdata->tg_trigtuple;
			}
			else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
			{
				pltevent = PyString_FromString("UPDATE");

				pytnew = PLyDict_FromTuple(&(proc->result), tdata->tg_newtuple,
										   tdata->tg_relation->rd_att);
				PyDict_SetItemString(pltdata, "new", pytnew);
				Py_DECREF(pytnew);
				pytold = PLyDict_FromTuple(&(proc->result), tdata->tg_trigtuple,
										   tdata->tg_relation->rd_att);
				PyDict_SetItemString(pltdata, "old", pytold);
				Py_DECREF(pytold);
				*rv = tdata->tg_newtuple;
			}
			else
			{
				elog(ERROR, "unrecognized OP tg_event: %u", tdata->tg_event);
				pltevent = NULL;	/* keep compiler quiet */
			}

			PyDict_SetItemString(pltdata, "event", pltevent);
			Py_DECREF(pltevent);
		}
		else if (TRIGGER_FIRED_FOR_STATEMENT(tdata->tg_event))
		{
			pltlevel = PyString_FromString("STATEMENT");
			PyDict_SetItemString(pltdata, "level", pltlevel);
			Py_DECREF(pltlevel);

			PyDict_SetItemString(pltdata, "old", Py_None);
			PyDict_SetItemString(pltdata, "new", Py_None);
			*rv = NULL;

			if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
				pltevent = PyString_FromString("INSERT");
			else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
				pltevent = PyString_FromString("DELETE");
			else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
				pltevent = PyString_FromString("UPDATE");
			else
			{
				elog(ERROR, "unrecognized OP tg_event: %u", tdata->tg_event);
				pltevent = NULL;	/* keep compiler quiet */
			}

			PyDict_SetItemString(pltdata, "event", pltevent);
			Py_DECREF(pltevent);
		}
		else
			elog(ERROR, "unrecognized LEVEL tg_event: %u", tdata->tg_event);

		if (tdata->tg_trigger->tgnargs)
		{
			/*
			 * all strings...
			 */
			int			i;
			PyObject   *pltarg;

			pltargs = PyList_New(tdata->tg_trigger->tgnargs);
			for (i = 0; i < tdata->tg_trigger->tgnargs; i++)
			{
				pltarg = PyString_FromString(tdata->tg_trigger->tgargs[i]);

				/*
				 * stolen, don't Py_DECREF
				 */
				PyList_SetItem(pltargs, i, pltarg);
			}
		}
		else
		{
			Py_INCREF(Py_None);
			pltargs = Py_None;
		}
		PyDict_SetItemString(pltdata, "args", pltargs);
		Py_DECREF(pltargs);
	}
	PG_CATCH();
	{
		Py_XDECREF(pltdata);
		PG_RE_THROW();
	}
	PG_END_TRY();

	return pltdata;
}



/* function handler and friends
 */
static Datum
PLy_function_handler(FunctionCallInfo fcinfo, PLyProcedure * proc)
{
	Datum		rv;
	PyObject   *volatile plargs = NULL;
	PyObject   *volatile plrv = NULL;
	PyObject   *volatile plrv_so = NULL;
	char	   *plrv_sc;

	PG_TRY();
	{
		plargs = PLy_function_build_args(fcinfo, proc);
		plrv = PLy_procedure_call(proc, "args", plargs);

		Assert(plrv != NULL);
		Assert(!PLy_error_in_progress);

		/*
		 * Disconnect from SPI manager and then create the return values datum
		 * (if the input function does a palloc for it this must not be
		 * allocated in the SPI memory context because SPI_finish would free
		 * it).
		 */
		if (SPI_finish() != SPI_OK_FINISH)
			elog(ERROR, "SPI_finish failed");

		/*
		 * convert the python PyObject to a postgresql Datum
		 */
		if (plrv == Py_None)
		{
			fcinfo->isnull = true;
			rv = (Datum) NULL;
		}
		else
		{
			fcinfo->isnull = false;
			plrv_so = PyObject_Str(plrv);
			if (!plrv_so)
				PLy_elog(ERROR, "function \"%s\" could not create return value", proc->proname);
			plrv_sc = PyString_AsString(plrv_so);
			rv = FunctionCall3(&proc->result.out.d.typfunc,
							   PointerGetDatum(plrv_sc),
							 ObjectIdGetDatum(proc->result.out.d.typioparam),
							   Int32GetDatum(-1));
		}

	}
	PG_CATCH();
	{
		Py_XDECREF(plargs);
		Py_XDECREF(plrv);
		Py_XDECREF(plrv_so);

		PG_RE_THROW();
	}
	PG_END_TRY();

	Py_XDECREF(plargs);
	Py_DECREF(plrv);
	Py_XDECREF(plrv_so);

	return rv;
}

static PyObject *
PLy_procedure_call(PLyProcedure * proc, char *kargs, PyObject * vargs)
{
	PyObject   *rv;

	PyDict_SetItemString(proc->globals, kargs, vargs);
	rv = PyEval_EvalCode((PyCodeObject *) proc->code,
						 proc->globals, proc->globals);

	/*
	 * If there was an error in a PG callback, propagate that no matter what
	 * Python claims about its success.
	 */
	if (PLy_error_in_progress)
	{
		ErrorData  *edata = PLy_error_in_progress;

		PLy_error_in_progress = NULL;
		ReThrowError(edata);
	}

	if ((rv == NULL) || (PyErr_Occurred()))
	{
		Py_XDECREF(rv);
		PLy_elog(ERROR, "function \"%s\" failed", proc->proname);
	}

	return rv;
}

static PyObject *
PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure * proc)
{
	PyObject   *volatile arg = NULL;
	PyObject   *volatile args = NULL;
	int			i;

	PG_TRY();
	{
		args = PyList_New(proc->nargs);
		for (i = 0; i < proc->nargs; i++)
		{
			if (proc->args[i].is_rowtype > 0)
			{
				if (fcinfo->argnull[i])
					arg = NULL;
				else
				{
					HeapTupleHeader td;
					Oid			tupType;
					int32		tupTypmod;
					TupleDesc	tupdesc;
					HeapTupleData tmptup;

					td = DatumGetHeapTupleHeader(fcinfo->arg[i]);
					/* Extract rowtype info and find a tupdesc */
					tupType = HeapTupleHeaderGetTypeId(td);
					tupTypmod = HeapTupleHeaderGetTypMod(td);
					tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
					tupdesc = CreateTupleDescCopy(tupdesc);

					/* Set up I/O funcs if not done yet */
					if (proc->args[i].is_rowtype != 1)
						PLy_input_tuple_funcs(&(proc->args[i]), tupdesc);

					/* Build a temporary HeapTuple control structure */
					tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
					tmptup.t_data = td;

					arg = PLyDict_FromTuple(&(proc->args[i]), &tmptup, tupdesc);
					FreeTupleDesc(tupdesc);
				}
			}
			else
			{
				if (fcinfo->argnull[i])
					arg = NULL;
				else
				{
					char	   *ct;
					Datum		dt;

					dt = FunctionCall3(&(proc->args[i].in.d.typfunc),
									   fcinfo->arg[i],
							 ObjectIdGetDatum(proc->args[i].in.d.typioparam),
									   Int32GetDatum(-1));
					ct = DatumGetCString(dt);
					arg = (proc->args[i].in.d.func) (ct);
					pfree(ct);
				}
			}

			if (arg == NULL)
			{
				Py_INCREF(Py_None);
				arg = Py_None;
			}

			/*
			 * FIXME -- error check this
			 */
			PyList_SetItem(args, i, arg);
			arg = NULL;
		}
	}
	PG_CATCH();
	{
		Py_XDECREF(arg);
		Py_XDECREF(args);

		PG_RE_THROW();
	}
	PG_END_TRY();

	return args;
}


/*
 * PLyProcedure functions
 */

/* PLy_procedure_get: returns a cached PLyProcedure, or creates, stores and
 * returns a new PLyProcedure.	fcinfo is the call info, tgreloid is the
 * relation OID when calling a trigger, or InvalidOid (zero) for ordinary
 * function calls.
 */
static PLyProcedure *
PLy_procedure_get(FunctionCallInfo fcinfo, Oid tgreloid)
{
	Oid			fn_oid;
	HeapTuple	procTup;
	char		key[128];
	PyObject   *plproc;
	PLyProcedure *proc = NULL;
	int			rv;

	fn_oid = fcinfo->flinfo->fn_oid;
	procTup = SearchSysCache(PROCOID,
							 ObjectIdGetDatum(fn_oid),
							 0, 0, 0);
	if (!HeapTupleIsValid(procTup))
		elog(ERROR, "cache lookup failed for function %u", fn_oid);

	rv = snprintf(key, sizeof(key), "%u_%u", fn_oid, tgreloid);
	if ((rv >= sizeof(key)) || (rv < 0))
		elog(ERROR, "key too long");

	plproc = PyDict_GetItemString(PLy_procedure_cache, key);

	if (plproc != NULL)
	{
		Py_INCREF(plproc);
		if (!PyCObject_Check(plproc))
			elog(FATAL, "expected a PyCObject, didn't get one");

		proc = PyCObject_AsVoidPtr(plproc);
		if (proc->me != plproc)
			elog(FATAL, "proc->me != plproc");
		/* did we find an up-to-date cache entry? */
		if (proc->fn_xmin != HeapTupleHeaderGetXmin(procTup->t_data) ||
			proc->fn_cmin != HeapTupleHeaderGetCmin(procTup->t_data))
		{
			Py_DECREF(plproc);
			proc = NULL;
		}
	}

	if (proc == NULL)
		proc = PLy_procedure_create(fcinfo, tgreloid, procTup, key);

	ReleaseSysCache(procTup);

	return proc;
}

static PLyProcedure *
PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
					 HeapTuple procTup, char *key)
{
	char		procName[NAMEDATALEN + 256];
	Form_pg_proc procStruct;
	PLyProcedure *volatile proc;
	char	   *volatile procSource = NULL;
	Datum		prosrcdatum;
	bool		isnull;
	int			i,
				rv;

	procStruct = (Form_pg_proc) GETSTRUCT(procTup);

	if (OidIsValid(tgreloid))
		rv = snprintf(procName, sizeof(procName),
					  "__plpython_procedure_%s_%u_trigger_%u",
					  NameStr(procStruct->proname),
					  fcinfo->flinfo->fn_oid,
					  tgreloid);
	else
		rv = snprintf(procName, sizeof(procName),
					  "__plpython_procedure_%s_%u",
					  NameStr(procStruct->proname),
					  fcinfo->flinfo->fn_oid);
	if ((rv >= sizeof(procName)) || (rv < 0))
		elog(ERROR, "procedure name would overrun buffer");

	proc = PLy_malloc(sizeof(PLyProcedure));
	proc->proname = PLy_malloc(strlen(NameStr(procStruct->proname)) + 1);
	strcpy(proc->proname, NameStr(procStruct->proname));
	proc->pyname = PLy_malloc(strlen(procName) + 1);
	strcpy(proc->pyname, procName);
	proc->fn_xmin = HeapTupleHeaderGetXmin(procTup->t_data);
	proc->fn_cmin = HeapTupleHeaderGetCmin(procTup->t_data);
	/* Remember if function is STABLE/IMMUTABLE */
	proc->fn_readonly =
		(procStruct->provolatile != PROVOLATILE_VOLATILE);
	PLy_typeinfo_init(&proc->result);
	for (i = 0; i < FUNC_MAX_ARGS; i++)
		PLy_typeinfo_init(&proc->args[i]);
	proc->nargs = 0;
	proc->code = proc->statics = NULL;
	proc->globals = proc->me = NULL;

	PG_TRY();
	{
		/*
		 * get information required for output conversion of the return value,
		 * but only if this isn't a trigger.
		 */
		if (!CALLED_AS_TRIGGER(fcinfo))
		{
			HeapTuple	rvTypeTup;
			Form_pg_type rvTypeStruct;

			rvTypeTup = SearchSysCache(TYPEOID,
									ObjectIdGetDatum(procStruct->prorettype),
									   0, 0, 0);
			if (!HeapTupleIsValid(rvTypeTup))
				elog(ERROR, "cache lookup failed for type %u",
					 procStruct->prorettype);
			rvTypeStruct = (Form_pg_type) GETSTRUCT(rvTypeTup);

			/* Disallow pseudotype result */
			if (rvTypeStruct->typtype == 'p')
			{
				if (procStruct->prorettype == TRIGGEROID)
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("trigger functions may only be called as triggers")));
				else
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						   errmsg("plpython functions cannot return type %s",
								  format_type_be(procStruct->prorettype))));
			}

			if (rvTypeStruct->typtype == 'c')
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),