pltcl.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

		}
	}
	PG_CATCH();
	{
		pltcl_current_fcinfo = save_fcinfo;
		pltcl_current_prodesc = save_prodesc;
		PG_RE_THROW();
	}
	PG_END_TRY();

	pltcl_current_fcinfo = save_fcinfo;
	pltcl_current_prodesc = save_prodesc;

	return retval;
}


/*
 * Alternate handler for unsafe functions
 */
PG_FUNCTION_INFO_V1(pltclu_call_handler);

/* keep non-static */
Datum
pltclu_call_handler(PG_FUNCTION_ARGS)
{
	return pltcl_call_handler(fcinfo);
}

/**********************************************************************
 * pltcl_func_handler()		- Handler for regular function calls
 **********************************************************************/
static Datum
pltcl_func_handler(PG_FUNCTION_ARGS)
{
	pltcl_proc_desc *prodesc;
	Tcl_Interp *volatile interp;
	Tcl_DString tcl_cmd;
	Tcl_DString list_tmp;
	int			i;
	int			tcl_rc;
	Datum		retval;

	/* Connect to SPI manager */
	if (SPI_connect() != SPI_OK_CONNECT)
		elog(ERROR, "could not connect to SPI manager");

	/* Find or compile the function */
	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid, InvalidOid);

	pltcl_current_prodesc = prodesc;

	if (prodesc->lanpltrusted)
		interp = pltcl_safe_interp;
	else
		interp = pltcl_norm_interp;

	/************************************************************
	 * Create the tcl command to call the internal
	 * proc in the Tcl interpreter
	 ************************************************************/
	Tcl_DStringInit(&tcl_cmd);
	Tcl_DStringInit(&list_tmp);
	Tcl_DStringAppendElement(&tcl_cmd, prodesc->proname);

	/************************************************************
	 * Add all call arguments to the command
	 ************************************************************/
	PG_TRY();
	{
		for (i = 0; i < prodesc->nargs; i++)
		{
			if (prodesc->arg_is_rowtype[i])
			{
				/**************************************************
				 * For tuple values, add a list for 'array set ...'
				 **************************************************/
				if (fcinfo->argnull[i])
					Tcl_DStringAppendElement(&tcl_cmd, "");
				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);
					/* Build a temporary HeapTuple control structure */
					tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
					tmptup.t_data = td;

					Tcl_DStringSetLength(&list_tmp, 0);
					pltcl_build_tuple_argument(&tmptup, tupdesc, &list_tmp);
					Tcl_DStringAppendElement(&tcl_cmd,
											 Tcl_DStringValue(&list_tmp));
					FreeTupleDesc(tupdesc);
				}
			}
			else
			{
				/**************************************************
				 * Single values are added as string element
				 * of their external representation
				 **************************************************/
				if (fcinfo->argnull[i])
					Tcl_DStringAppendElement(&tcl_cmd, "");
				else
				{
					char	   *tmp;

					tmp = DatumGetCString(FunctionCall1(&prodesc->arg_out_func[i],
														fcinfo->arg[i]));
					UTF_BEGIN;
					Tcl_DStringAppendElement(&tcl_cmd, UTF_E2U(tmp));
					UTF_END;
					pfree(tmp);
				}
			}
		}
	}
	PG_CATCH();
	{
		Tcl_DStringFree(&tcl_cmd);
		Tcl_DStringFree(&list_tmp);
		PG_RE_THROW();
	}
	PG_END_TRY();
	Tcl_DStringFree(&list_tmp);

	/************************************************************
	 * Call the Tcl function
	 *
	 * We assume no PG error can be thrown directly from this call.
	 ************************************************************/
	tcl_rc = Tcl_GlobalEval(interp, Tcl_DStringValue(&tcl_cmd));
	Tcl_DStringFree(&tcl_cmd);

	/************************************************************
	 * Check for errors reported by Tcl.
	 ************************************************************/
	if (tcl_rc != TCL_OK)
	{
		UTF_BEGIN;
		ereport(ERROR,
				(errmsg("%s", interp->result),
				 errcontext("%s",
							UTF_U2E(Tcl_GetVar(interp, "errorInfo",
											   TCL_GLOBAL_ONLY)))));
		UTF_END;
	}

	/************************************************************
	 * Disconnect from SPI manager and then create the return
	 * value 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).  But don't try to call
	 * the result_in_func if we've been told to return a NULL;
	 * the contents of interp->result may not be a valid value of
	 * the result type in that case.
	 ************************************************************/
	if (SPI_finish() != SPI_OK_FINISH)
		elog(ERROR, "SPI_finish() failed");

	if (fcinfo->isnull)
		retval = (Datum) 0;
	else
	{
		UTF_BEGIN;
		retval = FunctionCall3(&prodesc->result_in_func,
							   PointerGetDatum(UTF_U2E(interp->result)),
							   ObjectIdGetDatum(prodesc->result_typioparam),
							   Int32GetDatum(-1));
		UTF_END;
	}

	return retval;
}


/**********************************************************************
 * pltcl_trigger_handler()	- Handler for trigger calls
 **********************************************************************/
static HeapTuple
pltcl_trigger_handler(PG_FUNCTION_ARGS)
{
	pltcl_proc_desc *prodesc;
	Tcl_Interp *volatile interp;
	TriggerData *trigdata = (TriggerData *) fcinfo->context;
	char	   *stroid;
	TupleDesc	tupdesc;
	volatile HeapTuple rettup;
	Tcl_DString tcl_cmd;
	Tcl_DString tcl_trigtup;
	Tcl_DString tcl_newtup;
	int			tcl_rc;
	int			i;
	int		   *modattrs;
	Datum	   *modvalues;
	char	   *modnulls;
	int			ret_numvals;
	CONST84 char **ret_values;

	/* Connect to SPI manager */
	if (SPI_connect() != SPI_OK_CONNECT)
		elog(ERROR, "could not connect to SPI manager");

	/* Find or compile the function */
	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid,
									 RelationGetRelid(trigdata->tg_relation));

	pltcl_current_prodesc = prodesc;

	if (prodesc->lanpltrusted)
		interp = pltcl_safe_interp;
	else
		interp = pltcl_norm_interp;

	tupdesc = trigdata->tg_relation->rd_att;

	/************************************************************
	 * Create the tcl command to call the internal
	 * proc in the interpreter
	 ************************************************************/
	Tcl_DStringInit(&tcl_cmd);
	Tcl_DStringInit(&tcl_trigtup);
	Tcl_DStringInit(&tcl_newtup);
	PG_TRY();
	{
		/* The procedure name */
		Tcl_DStringAppendElement(&tcl_cmd, prodesc->proname);

		/* The trigger name for argument TG_name */
		Tcl_DStringAppendElement(&tcl_cmd, trigdata->tg_trigger->tgname);

		/* The oid of the trigger relation for argument TG_relid */
		stroid = DatumGetCString(DirectFunctionCall1(oidout,
							ObjectIdGetDatum(trigdata->tg_relation->rd_id)));
		Tcl_DStringAppendElement(&tcl_cmd, stroid);
		pfree(stroid);

		/* A list of attribute names for argument TG_relatts */
		Tcl_DStringAppendElement(&tcl_trigtup, "");
		for (i = 0; i < tupdesc->natts; i++)
		{
			if (tupdesc->attrs[i]->attisdropped)
				Tcl_DStringAppendElement(&tcl_trigtup, "");
			else
				Tcl_DStringAppendElement(&tcl_trigtup,
										 NameStr(tupdesc->attrs[i]->attname));
		}
		Tcl_DStringAppendElement(&tcl_cmd, Tcl_DStringValue(&tcl_trigtup));
		Tcl_DStringFree(&tcl_trigtup);
		Tcl_DStringInit(&tcl_trigtup);

		/* The when part of the event for TG_when */
		if (TRIGGER_FIRED_BEFORE(trigdata->tg_event))
			Tcl_DStringAppendElement(&tcl_cmd, "BEFORE");
		else if (TRIGGER_FIRED_AFTER(trigdata->tg_event))
			Tcl_DStringAppendElement(&tcl_cmd, "AFTER");
		else
			elog(ERROR, "unrecognized WHEN tg_event: %u", trigdata->tg_event);

		/* The level part of the event for TG_level */
		if (TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
		{
			Tcl_DStringAppendElement(&tcl_cmd, "ROW");

			/* Build the data list for the trigtuple */
			pltcl_build_tuple_argument(trigdata->tg_trigtuple,
									   tupdesc, &tcl_trigtup);

			/*
			 * Now the command part of the event for TG_op and data for NEW
			 * and OLD
			 */
			if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
			{
				Tcl_DStringAppendElement(&tcl_cmd, "INSERT");

				Tcl_DStringAppendElement(&tcl_cmd, Tcl_DStringValue(&tcl_trigtup));
				Tcl_DStringAppendElement(&tcl_cmd, "");

				rettup = trigdata->tg_trigtuple;
			}
			else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
			{
				Tcl_DStringAppendElement(&tcl_cmd, "DELETE");

				Tcl_DStringAppendElement(&tcl_cmd, "");
				Tcl_DStringAppendElement(&tcl_cmd, Tcl_DStringValue(&tcl_trigtup));

				rettup = trigdata->tg_trigtuple;
			}
			else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
			{
				Tcl_DStringAppendElement(&tcl_cmd, "UPDATE");

				pltcl_build_tuple_argument(trigdata->tg_newtuple,
										   tupdesc, &tcl_newtup);

				Tcl_DStringAppendElement(&tcl_cmd, Tcl_DStringValue(&tcl_newtup));
				Tcl_DStringAppendElement(&tcl_cmd, Tcl_DStringValue(&tcl_trigtup));

				rettup = trigdata->tg_newtuple;
			}
			else
				elog(ERROR, "unrecognized OP tg_event: %u", trigdata->tg_event);
		}
		else if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event))
		{
			Tcl_DStringAppendElement(&tcl_cmd, "STATEMENT");

			if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
				Tcl_DStringAppendElement(&tcl_cmd, "INSERT");
			else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
				Tcl_DStringAppendElement(&tcl_cmd, "DELETE");
			else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
				Tcl_DStringAppendElement(&tcl_cmd, "UPDATE");
			else
				elog(ERROR, "unrecognized OP tg_event: %u", trigdata->tg_event);

			Tcl_DStringAppendElement(&tcl_cmd, "");
			Tcl_DStringAppendElement(&tcl_cmd, "");

			rettup = (HeapTuple) NULL;
		}
		else
			elog(ERROR, "unrecognized LEVEL tg_event: %u", trigdata->tg_event);

		/* Finally append the arguments from CREATE TRIGGER */
		for (i = 0; i < trigdata->tg_trigger->tgnargs; i++)
			Tcl_DStringAppendElement(&tcl_cmd, trigdata->tg_trigger->tgargs[i]);

	}
	PG_CATCH();
	{
		Tcl_DStringFree(&tcl_cmd);
		Tcl_DStringFree(&tcl_trigtup);
		Tcl_DStringFree(&tcl_newtup);
		PG_RE_THROW();
	}
	PG_END_TRY();
	Tcl_DStringFree(&tcl_trigtup);
	Tcl_DStringFree(&tcl_newtup);

	/************************************************************
	 * Call the Tcl function
	 *
	 * We assume no PG error can be thrown directly from this call.
	 ************************************************************/
	tcl_rc = Tcl_GlobalEval(interp, Tcl_DStringValue(&tcl_cmd));
	Tcl_DStringFree(&tcl_cmd);

	/************************************************************
	 * Check for errors reported by Tcl.
	 ************************************************************/
	if (tcl_rc != TCL_OK)
	{
		UTF_BEGIN;
		ereport(ERROR,
				(errmsg("%s", interp->result),
				 errcontext("%s",
							UTF_U2E(Tcl_GetVar(interp, "errorInfo",
											   TCL_GLOBAL_ONLY)))));
		UTF_END;
	}

	/************************************************************
	 * The return value from the procedure might be one of
	 * the magic strings OK or SKIP or a list from array get
	 ************************************************************/
	if (SPI_finish() != SPI_OK_FINISH)
		elog(ERROR, "SPI_finish() failed");

	if (strcmp(interp->result, "OK") == 0)
		return rettup;
	if (strcmp(interp->result, "SKIP") == 0)
		return (HeapTuple) NULL;

	/************************************************************
	 * Convert the result value from the Tcl interpreter
	 * and setup structures for SPI_modifytuple();
	 ************************************************************/
	if (Tcl_SplitList(interp, interp->result,
					  &ret_numvals, &ret_values) != TCL_OK)
		elog(ERROR, "could not split return value from trigger: %s",
			 interp->result);

	/* Use a TRY to ensure ret_values will get freed */
	PG_TRY();
	{

		if (ret_numvals % 2 != 0)
			elog(ERROR, "invalid return list from trigger - must have even # of elements");

		modattrs = (int *) palloc(tupdesc->natts * sizeof(int));
		modvalues = (Datum *) palloc(tupdesc->natts * sizeof(Datum));
		for (i = 0; i < tupdesc->natts; i++)
		{
			modattrs[i] = i + 1;
			modvalues[i] = (Datum) NULL;
		}

		modnulls = palloc(tupdesc->natts);
		memset(modnulls, 'n', tupdesc->natts);

		for (i = 0; i < ret_numvals; i += 2)
		{
			CONST84 char *ret_name = ret_values[i];
			CONST84 char *ret_value = ret_values[i + 1];
			int			attnum;
			HeapTuple	typeTup;
			Oid			typinput;
			Oid			typioparam;
			FmgrInfo	finfo;

			/************************************************************
			 * Ignore ".tupno" pseudo elements (see pltcl_set_tuple_values)
			 ************************************************************/
			if (strcmp(ret_name, ".tupno") == 0)
				continue;

			/************************************************************
			 * Get the attribute number
			 ************************************************************/
			attnum = SPI_fnumber(tupdesc, ret_name);
			if (attnum == SPI_ERROR_NOATTRIBUTE)
				elog(ERROR, "invalid attribute \"%s\"", ret_name);
			if (attnum <= 0)
				elog(ERROR, "cannot set system attribute \"%s\"", ret_name);

			/************************************************************
			 * Ignore dropped columns
			 ************************************************************/
			if (tupdesc->attrs[attnum - 1]->attisdropped)