typecmds.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 2,044 行 · 第 1/4 页

	procOid = LookupFuncName(procname, 2, argList, true);
	if (OidIsValid(procOid))
		return procOid;

	ereport(ERROR,
			(errcode(ERRCODE_UNDEFINED_FUNCTION),
			 errmsg("function %s does not exist",
					func_signature_string(procname, 1, argList))));

	return InvalidOid;			/* keep compiler quiet */
}


/*-------------------------------------------------------------------
 * DefineCompositeType
 *
 * Create a Composite Type relation.
 * `DefineRelation' does all the work, we just provide the correct
 * arguments!
 *
 * If the relation already exists, then 'DefineRelation' will abort
 * the xact...
 *
 * DefineCompositeType returns relid for use when creating
 * an implicit composite type during function creation
 *-------------------------------------------------------------------
 */
Oid
DefineCompositeType(const RangeVar *typevar, List *coldeflist)
{
	CreateStmt *createStmt = makeNode(CreateStmt);

	if (coldeflist == NIL)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
			 errmsg("composite type must have at least one attribute")));

	/*
	 * now create the parameters for keys/inheritance etc. All of them are
	 * nil...
	 */
	createStmt->relation = (RangeVar *) typevar;
	createStmt->tableElts = coldeflist;
	createStmt->inhRelations = NIL;
	createStmt->constraints = NIL;
	createStmt->hasoids = false;
	createStmt->oncommit = ONCOMMIT_NOOP;

	/*
	 * finally create the relation...
	 */
	return DefineRelation(createStmt, RELKIND_COMPOSITE_TYPE);
}

/*
 * AlterDomainDefault
 *
 * Routine implementing ALTER DOMAIN SET/DROP DEFAULT statements.
 */
void
AlterDomainDefault(List *names, Node *defaultRaw)
{
	TypeName   *typename;
	Oid			domainoid;
	HeapTuple	tup;
	ParseState *pstate;
	Relation	rel;
	char	   *defaultValue;
	Node	   *defaultExpr = NULL;		/* NULL if no default specified */
	Datum		new_record[Natts_pg_type];
	char		new_record_nulls[Natts_pg_type];
	char		new_record_repl[Natts_pg_type];
	HeapTuple	newtuple;
	Form_pg_type typTup;

	/* Make a TypeName so we can use standard type lookup machinery */
	typename = makeNode(TypeName);
	typename->names = names;
	typename->typmod = -1;
	typename->arrayBounds = NIL;

	/* Lock the domain in the type table */
	rel = heap_openr(TypeRelationName, RowExclusiveLock);

	/* Use LookupTypeName here so that shell types can be removed. */
	domainoid = LookupTypeName(typename);
	if (!OidIsValid(domainoid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type \"%s\" does not exist",
						TypeNameToString(typename))));

	tup = SearchSysCacheCopy(TYPEOID,
							 ObjectIdGetDatum(domainoid),
							 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "cache lookup failed for type %u", domainoid);

	/* Doesn't return if user isn't allowed to alter the domain */
	domainOwnerCheck(tup, typename);

	/* Setup new tuple */
	MemSet(new_record, (Datum) 0, sizeof(new_record));
	MemSet(new_record_nulls, ' ', sizeof(new_record_nulls));
	MemSet(new_record_repl, ' ', sizeof(new_record_repl));

	/* Useful later */
	typTup = (Form_pg_type) GETSTRUCT(tup);

	/* Store the new default, if null then skip this step */
	if (defaultRaw)
	{
		/* Create a dummy ParseState for transformExpr */
		pstate = make_parsestate(NULL);

		/*
		 * Cook the colDef->raw_expr into an expression. Note: Name is
		 * strictly for error message
		 */
		defaultExpr = cookDefault(pstate, defaultRaw,
								  typTup->typbasetype,
								  typTup->typtypmod,
								  NameStr(typTup->typname));

		/*
		 * Expression must be stored as a nodeToString result, but we also
		 * require a valid textual representation (mainly to make life
		 * easier for pg_dump).
		 */
		defaultValue = deparse_expression(defaultExpr,
							deparse_context_for(NameStr(typTup->typname),
												InvalidOid),
										  false, false);

		/*
		 * Form an updated tuple with the new default and write it back.
		 */
		new_record[Anum_pg_type_typdefaultbin - 1] = DirectFunctionCall1(textin,
														 CStringGetDatum(
											 nodeToString(defaultExpr)));

		new_record_repl[Anum_pg_type_typdefaultbin - 1] = 'r';
		new_record[Anum_pg_type_typdefault - 1] = DirectFunctionCall1(textin,
										  CStringGetDatum(defaultValue));
		new_record_repl[Anum_pg_type_typdefault - 1] = 'r';
	}
	else
/* Default is NULL, drop it */
	{
		new_record_nulls[Anum_pg_type_typdefaultbin - 1] = 'n';
		new_record_repl[Anum_pg_type_typdefaultbin - 1] = 'r';
		new_record_nulls[Anum_pg_type_typdefault - 1] = 'n';
		new_record_repl[Anum_pg_type_typdefault - 1] = 'r';
	}

	newtuple = heap_modifytuple(tup, rel,
						  new_record, new_record_nulls, new_record_repl);

	simple_heap_update(rel, &tup->t_self, newtuple);

	CatalogUpdateIndexes(rel, newtuple);

	/* Rebuild dependencies */
	GenerateTypeDependencies(typTup->typnamespace,
							 domainoid,
							 typTup->typrelid,
							 0, /* relation kind is n/a */
							 typTup->typinput,
							 typTup->typoutput,
							 typTup->typreceive,
							 typTup->typsend,
							 typTup->typelem,
							 typTup->typbasetype,
							 defaultExpr,
							 true);		/* Rebuild is true */

	/* Clean up */
	heap_close(rel, NoLock);
	heap_freetuple(newtuple);
}

/*
 * AlterDomainNotNull
 *
 * Routine implementing ALTER DOMAIN SET/DROP NOT NULL statements.
 */
void
AlterDomainNotNull(List *names, bool notNull)
{
	TypeName   *typename;
	Oid			domainoid;
	Relation	typrel;
	HeapTuple	tup;
	Form_pg_type typTup;

	/* Make a TypeName so we can use standard type lookup machinery */
	typename = makeNode(TypeName);
	typename->names = names;
	typename->typmod = -1;
	typename->arrayBounds = NIL;

	/* Lock the type table */
	typrel = heap_openr(TypeRelationName, RowExclusiveLock);

	/* Use LookupTypeName here so that shell types can be found (why?). */
	domainoid = LookupTypeName(typename);
	if (!OidIsValid(domainoid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type \"%s\" does not exist",
						TypeNameToString(typename))));

	tup = SearchSysCacheCopy(TYPEOID,
							 ObjectIdGetDatum(domainoid),
							 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "cache lookup failed for type %u", domainoid);
	typTup = (Form_pg_type) GETSTRUCT(tup);

	/* Doesn't return if user isn't allowed to alter the domain */
	domainOwnerCheck(tup, typename);

	/* Is the domain already set to the desired constraint? */
	if (typTup->typnotnull == notNull)
	{
		heap_close(typrel, RowExclusiveLock);
		return;
	}

	/* Adding a NOT NULL constraint requires checking existing columns */
	if (notNull)
	{
		List	   *rels;
		List	   *rt;

		/* Fetch relation list with attributes based on this domain */
		/* ShareLock is sufficient to prevent concurrent data changes */

		rels = get_rels_with_domain(domainoid, ShareLock);

		foreach(rt, rels)
		{
			RelToCheck *rtc = (RelToCheck *) lfirst(rt);
			Relation	testrel = rtc->rel;
			TupleDesc	tupdesc = RelationGetDescr(testrel);
			HeapScanDesc scan;
			HeapTuple	tuple;

			/* Scan all tuples in this relation */
			scan = heap_beginscan(testrel, SnapshotNow, 0, NULL);
			while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
			{
				int			i;

				/* Test attributes that are of the domain */
				for (i = 0; i < rtc->natts; i++)
				{
					int			attnum = rtc->atts[i];
					Datum		d;
					bool		isNull;

					d = heap_getattr(tuple, attnum, tupdesc, &isNull);

					if (isNull)
						ereport(ERROR,
								(errcode(ERRCODE_NOT_NULL_VIOLATION),
								 errmsg("column \"%s\" of table \"%s\" contains null values",
										NameStr(tupdesc->attrs[attnum - 1]->attname),
										RelationGetRelationName(testrel))));
				}
			}
			heap_endscan(scan);

			/* Close each rel after processing, but keep lock */
			heap_close(testrel, NoLock);
		}
	}

	/*
	 * Okay to update pg_type row.	We can scribble on typTup because it's
	 * a copy.
	 */
	typTup->typnotnull = notNull;

	simple_heap_update(typrel, &tup->t_self, tup);

	CatalogUpdateIndexes(typrel, tup);

	/* Clean up */
	heap_freetuple(tup);
	heap_close(typrel, RowExclusiveLock);
}

/*
 * AlterDomainDropConstraint
 *
 * Implements the ALTER DOMAIN DROP CONSTRAINT statement
 */
void
AlterDomainDropConstraint(List *names, const char *constrName, DropBehavior behavior)
{
	TypeName   *typename;
	Oid			domainoid;
	HeapTuple	tup;
	Relation	rel;
	Form_pg_type typTup;
	Relation	conrel;
	SysScanDesc conscan;
	ScanKeyData key[1];
	HeapTuple	contup;

	/* Make a TypeName so we can use standard type lookup machinery */
	typename = makeNode(TypeName);
	typename->names = names;
	typename->typmod = -1;
	typename->arrayBounds = NIL;

	/* Lock the type table */
	rel = heap_openr(TypeRelationName, RowExclusiveLock);

	/* Use LookupTypeName here so that shell types can be removed. */
	domainoid = LookupTypeName(typename);
	if (!OidIsValid(domainoid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type \"%s\" does not exist",
						TypeNameToString(typename))));

	tup = SearchSysCacheCopy(TYPEOID,
							 ObjectIdGetDatum(domainoid),
							 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "cache lookup failed for type %u", domainoid);

	/* Doesn't return if user isn't allowed to alter the domain */
	domainOwnerCheck(tup, typename);

	/* Grab an appropriate lock on the pg_constraint relation */
	conrel = heap_openr(ConstraintRelationName, RowExclusiveLock);

	/* Use the index to scan only constraints of the target relation */
	ScanKeyEntryInitialize(&key[0], 0x0,
						   Anum_pg_constraint_contypid, F_OIDEQ,
						   ObjectIdGetDatum(HeapTupleGetOid(tup)));

	conscan = systable_beginscan(conrel, ConstraintTypidIndex, true,
								 SnapshotNow, 1, key);

	typTup = (Form_pg_type) GETSTRUCT(tup);

	/*
	 * Scan over the result set, removing any matching entries.
	 */
	while ((contup = systable_getnext(conscan)) != NULL)
	{
		Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(contup);

		if (strcmp(NameStr(con->conname), constrName) == 0)
		{
			ObjectAddress conobj;

			conobj.classId = RelationGetRelid(conrel);
			conobj.objectId = HeapTupleGetOid(contup);
			conobj.objectSubId = 0;

			performDeletion(&conobj, behavior);
		}
	}
	/* Clean up after the scan */
	systable_endscan(conscan);
	heap_close(conrel, RowExclusiveLock);

	heap_close(rel, NoLock);
}

/*
 * AlterDomainAddConstraint
 *
 * Implements the ALTER DOMAIN .. ADD CONSTRAINT statement.
 */
void
AlterDomainAddConstraint(List *names, Node *newConstraint)
{
	TypeName   *typename;
	Oid			domainoid;
	Relation	typrel;
	HeapTuple	tup;
	Form_pg_type typTup;
	List	   *rels;
	List	   *rt;
	EState	   *estate;
	ExprContext *econtext;
	char	   *ccbin;
	Expr	   *expr;
	ExprState  *exprstate;
	int			counter = 0;
	Constraint *constr;

	/* Make a TypeName so we can use standard type lookup machinery */
	typename = makeNode(TypeName);
	typename->names = names;
	typename->typmod = -1;
	typename->arrayBounds = NIL;

	/* Lock the type table */
	typrel = heap_openr(TypeRelationName, RowExclusiveLock);

	/* Use LookupTypeName here so that shell types can be found (why?). */
	domainoid = LookupTypeName(typename);
	if (!OidIsValid(domainoid))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("type \"%s\" does not exist",
						TypeNameToString(typename))));

	tup = SearchSysCacheCopy(TYPEOID,
							 ObjectIdGetDatum(domainoid),
							 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "cache lookup failed for type %u", domainoid);
	typTup = (Form_pg_type) GETSTRUCT(tup);

	/* Doesn't return if user isn't allowed to alter the domain */
	domainOwnerCheck(tup, typename);

	/* Check for unsupported constraint types */
	if (IsA(newConstraint, FkConstraint))
		ereport(ERROR,
				(errcode(ERRCODE_SYNTAX_ERROR),
		   errmsg("foreign key constraints not possible for domains")));

	/* otherwise it should be a plain Constraint */
	if (!IsA(newConstraint, Constraint))
		elog(ERROR, "unrecognized node type: %d",
			 (int) nodeTag(newConstraint));

	constr = (Constraint *) newConstraint;

	switch (constr->contype)
	{
		case CONSTR_CHECK:
			/* processed below */
			break;

		case CONSTR_UNIQUE:
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("unique constraints not possible for domains")));
			break;

		case CONSTR_PRIMARY:
			ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
					 errmsg("primary key constraints not possible for domains")));
			break;

		case CONSTR_ATTR_DEFERRABLE:
		case CONSTR_ATTR_NOT_DEFERRABLE:
		case CONSTR_ATTR_DEFERRED:
		case CONSTR_ATTR_IMMEDIATE:
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("specifying constraint deferrability not supported for domains")));
			break;

		default:
			elog(ERROR, "unrecognized constraint subtype: %d",
				 (int) constr->contype);
			break;
	}

	/*
	 * Since all other constraint types throw errors, this must be a check
	 * constraint.	First, process the constraint expression and add an
	 * entry to pg_constraint.
	 */

	ccbin = domainAddConstraint(HeapTupleGetOid(tup), typTup->typnamespace,
								typTup->typbasetype, typTup->typtypmod,
							 constr, &counter, NameStr(typTup->typname));

	/*
	 * Test all values stored in the attributes based on the domain the
	 * constraint is being added to.
	 */
	expr = (Expr *) stringToNode(ccbin);

	/* Need an EState to run ExecEvalExpr */
	estate = CreateExecutorState();
	econtext = GetPerTupleExprContext(estate);

	/* build execution state for expr */
	exprstate = ExecPrepareExpr(expr, estate);

	/* Fetch relation list with attributes based on this domain */
	/* ShareLock is sufficient to prevent concurrent data changes */

	rels = get_rels_with_domain(domainoid, ShareLock);

	foreach(rt, rels)
	{
		RelToCheck *rtc = (RelToCheck *) lfirst(rt);
		Relation	testrel = rtc->rel;
		TupleDesc	tupdesc = RelationGetDescr(testrel);
		HeapScanDesc scan;
		HeapTuple	tuple;

		/* Scan all tuples in this relation */
		scan = heap_beginscan(testrel, SnapshotNow, 0, NULL);
		while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)