pltcl.c

关系型数据库 Postgresql 6.5.2

pltcl_func_handler(FmgrInfo *proinfo,
				   FmgrValues *proargs,
				   bool *isNull)
{
	int			i;
	char		internal_proname[512];
	char	   *stroid;
	Tcl_HashEntry *hashent;
	int			hashnew;
	pltcl_proc_desc *prodesc;
	Tcl_DString tcl_cmd;
	Tcl_DString list_tmp;
	int			tcl_rc;
	Datum		retval;
	sigjmp_buf	save_restart;

	/************************************************************
	 * Build our internal proc name from the functions Oid
	 ************************************************************/
	stroid = oidout(proinfo->fn_oid);
	strcpy(internal_proname, "__PLTcl_proc_");
	strcat(internal_proname, stroid);
	pfree(stroid);

	/************************************************************
	 * Lookup the internal proc name in the hashtable
	 ************************************************************/
	hashent = Tcl_FindHashEntry(pltcl_proc_hash, internal_proname);
	if (hashent == NULL)
	{
		/************************************************************
		 * If we haven't found it in the hashtable, we analyze
		 * the functions arguments and returntype and store
		 * the in-/out-functions in the prodesc block and create
		 * a new hashtable entry for it.
		 *
		 * Then we load the procedure into the safe interpreter.
		 ************************************************************/
		HeapTuple	procTup;
		HeapTuple	typeTup;
		Form_pg_proc procStruct;
		Form_pg_type typeStruct;
		Tcl_DString proc_internal_def;
		Tcl_DString proc_internal_body;
		char		proc_internal_args[4096];
		char	   *proc_source;
		char		buf[512];

		/************************************************************
		 * Allocate a new procedure description block
		 ************************************************************/
		prodesc = (pltcl_proc_desc *) malloc(sizeof(pltcl_proc_desc));
		prodesc->proname = malloc(strlen(internal_proname) + 1);
		strcpy(prodesc->proname, internal_proname);

		/************************************************************
		 * Lookup the pg_proc tuple by Oid
		 ************************************************************/
		procTup = SearchSysCacheTuple(PROOID,
									  ObjectIdGetDatum(proinfo->fn_oid),
									  0, 0, 0);
		if (!HeapTupleIsValid(procTup))
		{
			free(prodesc->proname);
			free(prodesc);
			elog(ERROR, "pltcl: cache lookup from pg_proc failed");
		}
		procStruct = (Form_pg_proc) GETSTRUCT(procTup);

		/************************************************************
		 * Get the required information for input conversion of the
		 * return value.
		 ************************************************************/
		typeTup = SearchSysCacheTuple(TYPOID,
								ObjectIdGetDatum(procStruct->prorettype),
									  0, 0, 0);
		if (!HeapTupleIsValid(typeTup))
		{
			free(prodesc->proname);
			free(prodesc);
			elog(ERROR, "pltcl: cache lookup for return type failed");
		}
		typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

		if (typeStruct->typrelid != InvalidOid)
		{
			free(prodesc->proname);
			free(prodesc);
			elog(ERROR, "pltcl: return types of tuples not supported yet");
		}

		fmgr_info(typeStruct->typinput, &(prodesc->result_in_func));
		prodesc->result_in_elem = (Oid) (typeStruct->typelem);
		prodesc->result_in_len = typeStruct->typlen;

		/************************************************************
		 * Get the required information for output conversion
		 * of all procedure arguments
		 ************************************************************/
		prodesc->nargs = proinfo->fn_nargs;
		proc_internal_args[0] = '\0';
		for (i = 0; i < proinfo->fn_nargs; i++)
		{
			typeTup = SearchSysCacheTuple(TYPOID,
							ObjectIdGetDatum(procStruct->proargtypes[i]),
										  0, 0, 0);
			if (!HeapTupleIsValid(typeTup))
			{
				free(prodesc->proname);
				free(prodesc);
				elog(ERROR, "pltcl: cache lookup for argument type failed");
			}
			typeStruct = (Form_pg_type) GETSTRUCT(typeTup);

			if (typeStruct->typrelid != InvalidOid)
			{
				prodesc->arg_is_rel[i] = 1;
				if (i > 0)
					strcat(proc_internal_args, " ");
				sprintf(buf, "__PLTcl_Tup_%d", i + 1);
				strcat(proc_internal_args, buf);
				continue;
			}
			else
				prodesc->arg_is_rel[i] = 0;

			fmgr_info(typeStruct->typoutput, &(prodesc->arg_out_func[i]));
			prodesc->arg_out_elem[i] = (Oid) (typeStruct->typelem);
			prodesc->arg_out_len[i] = typeStruct->typlen;

			if (i > 0)
				strcat(proc_internal_args, " ");
			sprintf(buf, "%d", i + 1);
			strcat(proc_internal_args, buf);
		}

		/************************************************************
		 * Create the tcl command to define the internal
		 * procedure
		 ************************************************************/
		Tcl_DStringInit(&proc_internal_def);
		Tcl_DStringInit(&proc_internal_body);
		Tcl_DStringAppendElement(&proc_internal_def, "proc");
		Tcl_DStringAppendElement(&proc_internal_def, internal_proname);
		Tcl_DStringAppendElement(&proc_internal_def, proc_internal_args);

		/************************************************************
		 * prefix procedure body with
		 * upvar #0 <internal_procname> GD
		 * and with appropriate upvars for tuple arguments
		 ************************************************************/
		Tcl_DStringAppend(&proc_internal_body, "upvar #0 ", -1);
		Tcl_DStringAppend(&proc_internal_body, internal_proname, -1);
		Tcl_DStringAppend(&proc_internal_body, " GD\n", -1);
		for (i = 0; i < proinfo->fn_nargs; i++)
		{
			if (!prodesc->arg_is_rel[i])
				continue;
			sprintf(buf, "array set %d $__PLTcl_Tup_%d\n", i + 1, i + 1);
			Tcl_DStringAppend(&proc_internal_body, buf, -1);
		}
		proc_source = textout(&(procStruct->prosrc));
		Tcl_DStringAppend(&proc_internal_body, proc_source, -1);
		pfree(proc_source);
		Tcl_DStringAppendElement(&proc_internal_def,
								 Tcl_DStringValue(&proc_internal_body));
		Tcl_DStringFree(&proc_internal_body);

		/************************************************************
		 * Create the procedure in the safe interpreter
		 ************************************************************/
		tcl_rc = Tcl_GlobalEval(pltcl_safe_interp,
								Tcl_DStringValue(&proc_internal_def));
		Tcl_DStringFree(&proc_internal_def);
		if (tcl_rc != TCL_OK)
		{
			free(prodesc->proname);
			free(prodesc);
			elog(ERROR, "pltcl: cannot create internal procedure %s - %s",
				 internal_proname, pltcl_safe_interp->result);
		}

		/************************************************************
		 * Add the proc description block to the hashtable
		 ************************************************************/
		hashent = Tcl_CreateHashEntry(pltcl_proc_hash,
									  prodesc->proname, &hashnew);
		Tcl_SetHashValue(hashent, (ClientData) prodesc);
	}
	else
	{
		/************************************************************
		 * Found the proc description block in the hashtable
		 ************************************************************/
		prodesc = (pltcl_proc_desc *) Tcl_GetHashValue(hashent);
	}

	/************************************************************
	 * Create the tcl command to call the internal
	 * proc in the safe interpreter
	 ************************************************************/
	Tcl_DStringInit(&tcl_cmd);
	Tcl_DStringInit(&list_tmp);
	Tcl_DStringAppendElement(&tcl_cmd, internal_proname);

	/************************************************************
	 * Catch elog(ERROR) during build of the Tcl command
	 ************************************************************/
	memcpy(&save_restart, &Warn_restart, sizeof(save_restart));
	if (sigsetjmp(Warn_restart, 1) != 0)
	{
		memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
		Tcl_DStringFree(&tcl_cmd);
		Tcl_DStringFree(&list_tmp);
		pltcl_restart_in_progress = 1;
		if (--pltcl_call_level == 0)
			pltcl_restart_in_progress = 0;
		siglongjmp(Warn_restart, 1);
	}

	/************************************************************
	 * Add all call arguments to the command
	 ************************************************************/
	for (i = 0; i < prodesc->nargs; i++)
	{
		if (prodesc->arg_is_rel[i])
		{
			/**************************************************
			 * For tuple values, add a list for 'array set ...'
			 **************************************************/
			Tcl_DStringInit(&list_tmp);
			pltcl_build_tuple_argument(
							((TupleTableSlot *) (proargs->data[i]))->val,
			((TupleTableSlot *) (proargs->data[i]))->ttc_tupleDescriptor,
									   &list_tmp);
			Tcl_DStringAppendElement(&tcl_cmd, Tcl_DStringValue(&list_tmp));
			Tcl_DStringFree(&list_tmp);
			Tcl_DStringInit(&list_tmp);
		}
		else
		{
			/**************************************************
			 * Single values are added as string element
			 * of their external representation
			 **************************************************/
			char	   *tmp;

			tmp = (*fmgr_faddr(&(prodesc->arg_out_func[i])))
				(proargs->data[i],
				 prodesc->arg_out_elem[i],
				 prodesc->arg_out_len[i]);
			Tcl_DStringAppendElement(&tcl_cmd, tmp);
			pfree(tmp);
		}
	}
	Tcl_DStringFree(&list_tmp);
	memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));

	/************************************************************
	 * Call the Tcl function
	 ************************************************************/
	tcl_rc = Tcl_GlobalEval(pltcl_safe_interp, Tcl_DStringValue(&tcl_cmd));
	Tcl_DStringFree(&tcl_cmd);

	/************************************************************
	 * Check the return code from Tcl and handle
	 * our special restart mechanism to get rid
	 * of all nested call levels on transaction
	 * abort.
	 ************************************************************/
	if (tcl_rc != TCL_OK || pltcl_restart_in_progress)
	{
		if (!pltcl_restart_in_progress)
		{
			pltcl_restart_in_progress = 1;
			if (--pltcl_call_level == 0)
				pltcl_restart_in_progress = 0;
			elog(ERROR, "pltcl: %s", pltcl_safe_interp->result);
		}
		if (--pltcl_call_level == 0)
			pltcl_restart_in_progress = 0;
		siglongjmp(Warn_restart, 1);
	}

	/************************************************************
	 * Convert the result value from the safe interpreter
	 * into it's PostgreSQL data format and return it.
	 * Again, the call to fmgr() could fire an elog and we
	 * have to count for the current interpreter level we are
	 * on. The save_restart from above is still good.
	 ************************************************************/
	if (sigsetjmp(Warn_restart, 1) != 0)
	{
		memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
		pltcl_restart_in_progress = 1;
		if (--pltcl_call_level == 0)
			pltcl_restart_in_progress = 0;
		siglongjmp(Warn_restart, 1);
	}

	/************************************************************
	 * 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, "pltcl: SPI_finish() failed");

	retval = (Datum) (*fmgr_faddr(&prodesc->result_in_func))
		(pltcl_safe_interp->result,
		 prodesc->result_in_elem,
		 prodesc->result_in_len);

	memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
	return retval;
}


/**********************************************************************
 * pltcl_trigger_handler()	- Handler for trigger calls
 **********************************************************************/
static HeapTuple
pltcl_trigger_handler(FmgrInfo *proinfo)
{
	TriggerData *trigdata;
	char		internal_proname[512];
	char	   *stroid;
	Tcl_HashEntry *hashent;
	int			hashnew;
	pltcl_proc_desc *prodesc;
	TupleDesc	tupdesc;
	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;
	char	  **ret_values;

	sigjmp_buf	save_restart;

	/************************************************************
	 * Save the current trigger data local
	 ************************************************************/
	trigdata = CurrentTriggerData;
	CurrentTriggerData = NULL;

	/************************************************************
	 * Build our internal proc name from the functions Oid
	 ************************************************************/
	stroid = oidout(proinfo->fn_oid);
	strcpy(internal_proname, "__PLTcl_proc_");
	strcat(internal_proname, stroid);
	pfree(stroid);

	/************************************************************
	 * Lookup the internal proc name in the hashtable
	 ************************************************************/
	hashent = Tcl_FindHashEntry(pltcl_proc_hash, internal_proname);
	if (hashent == NULL)
	{
		/************************************************************
		 * If we haven't found it in the hashtable,
		 * we load the procedure into the safe interpreter.
		 ************************************************************/
		Tcl_DString proc_internal_def;
		Tcl_DString proc_internal_body;
		HeapTuple	procTup;
		Form_pg_proc procStruct;
		char	   *proc_source;

		/************************************************************
		 * Allocate a new procedure description block
		 ************************************************************/
		prodesc = (pltcl_proc_desc *) malloc(sizeof(pltcl_proc_desc));
		memset(prodesc, 0, sizeof(pltcl_proc_desc));
		prodesc->proname = malloc(strlen(internal_proname) + 1);
		strcpy(prodesc->proname, internal_proname);

		/************************************************************
		 * Lookup the pg_proc tuple by Oid
		 ************************************************************/
		procTup = SearchSysCacheTuple(PROOID,
									  ObjectIdGetDatum(proinfo->fn_oid),
									  0, 0, 0);
		if (!HeapTupleIsValid(procTup))
		{
			free(prodesc->proname);
			free(prodesc);
			elog(ERROR, "pltcl: cache lookup from pg_proc failed");
		}
		procStruct = (Form_pg_proc) GETSTRUCT(procTup);

		/************************************************************
		 * Create the tcl command to define the internal
		 * procedure
		 ************************************************************/
		Tcl_DStringInit(&proc_internal_def);
		Tcl_DStringInit(&proc_internal_body);
		Tcl_DStringAppendElement(&proc_internal_def, "proc");
		Tcl_DStringAppendElement(&proc_internal_def, internal_proname);
		Tcl_DStringAppendElement(&proc_internal_def,
								 "TG_name TG_relid TG_relatts TG_when TG_level TG_op __PLTcl_Tup_NEW __PLTcl_Tup_OLD args");

		/************************************************************