pltcl.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

	SPI_freetuptable(tuptable);

	return my_rc;
}


/**********************************************************************
 * pltcl_SPI_prepare()		- Builtin support for prepared plans
 *				  The Tcl command SPI_prepare
 *				  always saves the plan using
 *				  SPI_saveplan and returns a key for
 *				  access. There is no chance to prepare
 *				  and not save the plan currently.
 **********************************************************************/
static int
pltcl_SPI_prepare(ClientData cdata, Tcl_Interp *interp,
				  int argc, CONST84 char *argv[])
{
	int			nargs;
	CONST84 char **args;
	pltcl_query_desc *qdesc;
	void	   *plan;
	int			i;
	HeapTuple	typeTup;
	Tcl_HashEntry *hashent;
	int			hashnew;
	Tcl_HashTable *query_hash;
	MemoryContext oldcontext = CurrentMemoryContext;
	ResourceOwner oldowner = CurrentResourceOwner;

	/************************************************************
	 * Check the call syntax
	 ************************************************************/
	if (argc != 3)
	{
		Tcl_SetResult(interp, "syntax error - 'SPI_prepare query argtypes'",
					  TCL_VOLATILE);
		return TCL_ERROR;
	}

	/************************************************************
	 * Split the argument type list
	 ************************************************************/
	if (Tcl_SplitList(interp, argv[2], &nargs, &args) != TCL_OK)
		return TCL_ERROR;

	/************************************************************
	 * Allocate the new querydesc structure
	 ************************************************************/
	qdesc = (pltcl_query_desc *) malloc(sizeof(pltcl_query_desc));
	snprintf(qdesc->qname, sizeof(qdesc->qname), "%lx", (long) qdesc);
	qdesc->nargs = nargs;
	qdesc->argtypes = (Oid *) malloc(nargs * sizeof(Oid));
	qdesc->arginfuncs = (FmgrInfo *) malloc(nargs * sizeof(FmgrInfo));
	qdesc->argtypioparams = (Oid *) malloc(nargs * sizeof(Oid));

	/************************************************************
	 * Execute the prepare inside a sub-transaction, so we can cope with
	 * errors sanely
	 ************************************************************/

	pltcl_subtrans_begin(oldcontext, oldowner);

	PG_TRY();
	{
		/************************************************************
		 * Lookup the argument types by name in the system cache
		 * and remember the required information for input conversion
		 ************************************************************/
		for (i = 0; i < nargs; i++)
		{
			char	   *argcopy;
			List	   *names = NIL;
			ListCell   *l;
			TypeName   *typename;

			/************************************************************
			 * Use SplitIdentifierString() on a copy of the type name,
			 * turn the resulting pointer list into a TypeName node
			 * and call typenameType() to get the pg_type tuple.
			 ************************************************************/
			argcopy = pstrdup(args[i]);
			SplitIdentifierString(argcopy, '.', &names);
			typename = makeNode(TypeName);
			foreach(l, names)
				typename->names = lappend(typename->names, makeString(lfirst(l)));

			typeTup = typenameType(typename);
			qdesc->argtypes[i] = HeapTupleGetOid(typeTup);
			perm_fmgr_info(((Form_pg_type) GETSTRUCT(typeTup))->typinput,
						   &(qdesc->arginfuncs[i]));
			qdesc->argtypioparams[i] = getTypeIOParam(typeTup);
			ReleaseSysCache(typeTup);

			list_free(typename->names);
			pfree(typename);
			list_free(names);
			pfree(argcopy);
		}

		/************************************************************
		 * Prepare the plan and check for errors
		 ************************************************************/
		UTF_BEGIN;
		plan = SPI_prepare(UTF_U2E(argv[1]), nargs, qdesc->argtypes);
		UTF_END;

		if (plan == NULL)
			elog(ERROR, "SPI_prepare() failed");

		/************************************************************
		 * Save the plan into permanent memory (right now it's in the
		 * SPI procCxt, which will go away at function end).
		 ************************************************************/
		qdesc->plan = SPI_saveplan(plan);
		if (qdesc->plan == NULL)
			elog(ERROR, "SPI_saveplan() failed");

		/* Release the procCxt copy to avoid within-function memory leak */
		SPI_freeplan(plan);

		pltcl_subtrans_commit(oldcontext, oldowner);
	}
	PG_CATCH();
	{
		pltcl_subtrans_abort(interp, oldcontext, oldowner);

		free(qdesc->argtypes);
		free(qdesc->arginfuncs);
		free(qdesc->argtypioparams);
		free(qdesc);
		ckfree((char *) args);

		return TCL_ERROR;
	}
	PG_END_TRY();

	/************************************************************
	 * Insert a hashtable entry for the plan and return
	 * the key to the caller
	 ************************************************************/
	if (interp == pltcl_norm_interp)
		query_hash = pltcl_norm_query_hash;
	else
		query_hash = pltcl_safe_query_hash;

	hashent = Tcl_CreateHashEntry(query_hash, qdesc->qname, &hashnew);
	Tcl_SetHashValue(hashent, (ClientData) qdesc);

	ckfree((char *) args);

	Tcl_SetResult(interp, qdesc->qname, TCL_VOLATILE);
	return TCL_OK;
}


/**********************************************************************
 * pltcl_SPI_execute_plan()		- Execute a prepared plan
 **********************************************************************/
static int
pltcl_SPI_execute_plan(ClientData cdata, Tcl_Interp *interp,
					   int argc, CONST84 char *argv[])
{
	int			my_rc;
	int			spi_rc;
	int			i;
	int			j;
	Tcl_HashEntry *hashent;
	pltcl_query_desc *qdesc;
	const char *volatile nulls = NULL;
	CONST84 char *volatile arrayname = NULL;
	CONST84 char *volatile loop_body = NULL;
	int			count = 0;
	int			callnargs;
	CONST84 char **callargs = NULL;
	Datum	   *argvalues;
	MemoryContext oldcontext = CurrentMemoryContext;
	ResourceOwner oldowner = CurrentResourceOwner;
	Tcl_HashTable *query_hash;

	char	   *usage = "syntax error - 'SPI_execp "
	"?-nulls string? ?-count n? "
	"?-array name? query ?args? ?loop body?";

	/************************************************************
	 * Get the options and check syntax
	 ************************************************************/
	i = 1;
	while (i < argc)
	{
		if (strcmp(argv[i], "-array") == 0)
		{
			if (++i >= argc)
			{
				Tcl_SetResult(interp, usage, TCL_VOLATILE);
				return TCL_ERROR;
			}
			arrayname = argv[i++];
			continue;
		}
		if (strcmp(argv[i], "-nulls") == 0)
		{
			if (++i >= argc)
			{
				Tcl_SetResult(interp, usage, TCL_VOLATILE);
				return TCL_ERROR;
			}
			nulls = argv[i++];
			continue;
		}
		if (strcmp(argv[i], "-count") == 0)
		{
			if (++i >= argc)
			{
				Tcl_SetResult(interp, usage, TCL_VOLATILE);
				return TCL_ERROR;
			}
			if (Tcl_GetInt(interp, argv[i++], &count) != TCL_OK)
				return TCL_ERROR;
			continue;
		}

		break;
	}

	/************************************************************
	 * Get the prepared plan descriptor by its key
	 ************************************************************/
	if (i >= argc)
	{
		Tcl_SetResult(interp, usage, TCL_VOLATILE);
		return TCL_ERROR;
	}

	if (interp == pltcl_norm_interp)
		query_hash = pltcl_norm_query_hash;
	else
		query_hash = pltcl_safe_query_hash;

	hashent = Tcl_FindHashEntry(query_hash, argv[i]);
	if (hashent == NULL)
	{
		Tcl_AppendResult(interp, "invalid queryid '", argv[i], "'", NULL);
		return TCL_ERROR;
	}
	qdesc = (pltcl_query_desc *) Tcl_GetHashValue(hashent);
	i++;

	/************************************************************
	 * If a nulls string is given, check for correct length
	 ************************************************************/
	if (nulls != NULL)
	{
		if (strlen(nulls) != qdesc->nargs)
		{
			Tcl_SetResult(interp,
					   "length of nulls string doesn't match # of arguments",
						  TCL_VOLATILE);
			return TCL_ERROR;
		}
	}

	/************************************************************
	 * If there was a argtype list on preparation, we need
	 * an argument value list now
	 ************************************************************/
	if (qdesc->nargs > 0)
	{
		if (i >= argc)
		{
			Tcl_SetResult(interp, "missing argument list", TCL_VOLATILE);
			return TCL_ERROR;
		}

		/************************************************************
		 * Split the argument values
		 ************************************************************/
		if (Tcl_SplitList(interp, argv[i++], &callnargs, &callargs) != TCL_OK)
			return TCL_ERROR;

		/************************************************************
		 * Check that the # of arguments matches
		 ************************************************************/
		if (callnargs != qdesc->nargs)
		{
			Tcl_SetResult(interp,
			   "argument list length doesn't match # of arguments for query",
						  TCL_VOLATILE);
			ckfree((char *) callargs);
			return TCL_ERROR;
		}
	}
	else
		callnargs = 0;

	/************************************************************
	 * Get loop body if present
	 ************************************************************/
	if (i < argc)
		loop_body = argv[i++];

	if (i != argc)
	{
		Tcl_SetResult(interp, usage, TCL_VOLATILE);
		return TCL_ERROR;
	}

	/************************************************************
	 * Execute the plan inside a sub-transaction, so we can cope with
	 * errors sanely
	 ************************************************************/

	pltcl_subtrans_begin(oldcontext, oldowner);

	PG_TRY();
	{
		/************************************************************
		 * Setup the value array for SPI_execute_plan() using
		 * the type specific input functions
		 ************************************************************/
		argvalues = (Datum *) palloc(callnargs * sizeof(Datum));

		for (j = 0; j < callnargs; j++)
		{
			if (nulls && nulls[j] == 'n')
			{
				/* don't try to convert the input for a null */
				argvalues[j] = (Datum) 0;
			}
			else
			{
				UTF_BEGIN;
				argvalues[j] =
					FunctionCall3(&qdesc->arginfuncs[j],
								  CStringGetDatum(UTF_U2E(callargs[j])),
								  ObjectIdGetDatum(qdesc->argtypioparams[j]),
								  Int32GetDatum(-1));
				UTF_END;
			}
		}

		if (callargs)
			ckfree((char *) callargs);
		callargs = NULL;

		/************************************************************
		 * Execute the plan
		 ************************************************************/
		spi_rc = SPI_execute_plan(qdesc->plan, argvalues, nulls,
								  pltcl_current_prodesc->fn_readonly, count);

		my_rc = pltcl_process_SPI_result(interp,
										 arrayname,
										 loop_body,
										 spi_rc,
										 SPI_tuptable,
										 SPI_processed);

		pltcl_subtrans_commit(oldcontext, oldowner);
	}
	PG_CATCH();
	{
		pltcl_subtrans_abort(interp, oldcontext, oldowner);

		if (callargs)
			ckfree((char *) callargs);

		return TCL_ERROR;
	}
	PG_END_TRY();

	return my_rc;
}


/**********************************************************************
 * pltcl_SPI_lastoid()	- return the last oid. To
 *		  be used after insert queries
 **********************************************************************/
static int
pltcl_SPI_lastoid(ClientData cdata, Tcl_Interp *interp,
				  int argc, CONST84 char *argv[])
{
	char		buf[64];

	snprintf(buf, sizeof(buf), "%u", SPI_lastoid);
	Tcl_SetResult(interp, buf, TCL_VOLATILE);
	return TCL_OK;
}


/**********************************************************************
 * pltcl_set_tuple_values() - Set variables for all attributes
 *				  of a given tuple
 **********************************************************************/
static void
pltcl_set_tuple_values(Tcl_Interp *interp, CONST84 char *arrayname,
					   int tupno, HeapTuple tuple, TupleDesc tupdesc)
{
	int			i;
	char	   *outputstr;
	char		buf[64];
	Datum		attr;
	bool		isnull;

	CONST84 char *attname;
	HeapTuple	typeTup;
	Oid			typoutput;

	CONST84 char **arrptr;
	CONST84 char **nameptr;
	CONST84 char *nullname = NULL;

	/************************************************************
	 * Prepare pointers for Tcl_SetVar2() below and in array
	 * mode set the .tupno element
	 ************************************************************/
	if (arrayname == NULL)
	{
		arrptr = &attname;
		nameptr = &nullname;
	}
	else
	{
		arrptr = &arrayname;
		nameptr = &attname;
		snprintf(buf, sizeof(buf), "%d", tupno);
		Tcl_SetVar2(interp, arrayname, ".tupno", buf, 0);
	}

	for (i = 0; i < tupdesc->natts; i++)
	{
		/* ignore dropped attributes */
		if (tupdesc->attrs[i]->attisdropped)
			continue;

		/************************************************************
		 * Get the attribute name
		 ************************************************************/
		attname = NameStr(tupdesc