typecmds.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

						 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "cache lookup failed for type %u", typeOid);

	simple_heap_delete(relation, &tup->t_self);

	ReleaseSysCache(tup);

	heap_close(relation, RowExclusiveLock);
}


/*
 * DefineDomain
 *		Registers a new domain.
 */
void
DefineDomain(CreateDomainStmt *stmt)
{
	char	   *domainName;
	Oid			domainNamespace;
	AclResult	aclresult;
	int16		internalLength;
	Oid			inputProcedure;
	Oid			outputProcedure;
	Oid			receiveProcedure;
	Oid			sendProcedure;
	Oid			analyzeProcedure;
	bool		byValue;
	char		delimiter;
	char		alignment;
	char		storage;
	char		typtype;
	Datum		datum;
	bool		isnull;
	Node	   *defaultExpr = NULL;
	char	   *defaultValue = NULL;
	char	   *defaultValueBin = NULL;
	bool		typNotNull = false;
	bool		nullDefined = false;
	Oid			basetypelem;
	int32		typNDims = list_length(stmt->typename->arrayBounds);
	HeapTuple	typeTup;
	List	   *schema = stmt->constraints;
	ListCell   *listptr;
	Oid			basetypeoid;
	Oid			domainoid;
	Form_pg_type baseType;

	/* Convert list of names to a name and namespace */
	domainNamespace = QualifiedNameGetCreationNamespace(stmt->domainname,
														&domainName);

	/* Check we have creation rights in target namespace */
	aclresult = pg_namespace_aclcheck(domainNamespace, GetUserId(),
									  ACL_CREATE);
	if (aclresult != ACLCHECK_OK)
		aclcheck_error(aclresult, ACL_KIND_NAMESPACE,
					   get_namespace_name(domainNamespace));

	/*
	 * Domainnames, unlike typenames don't need to account for the '_' prefix.
	 * So they can be one character longer.  (This test is presently useless
	 * since the parser will have truncated the name to fit.  But leave it
	 * here since we may someday support arrays of domains, in which case
	 * we'll be back to needing to enforce NAMEDATALEN-2.)
	 */
	if (strlen(domainName) > (NAMEDATALEN - 1))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_NAME),
				 errmsg("domain names must be %d characters or less",
						NAMEDATALEN - 1)));

	/*
	 * Look up the base type.
	 */
	typeTup = typenameType(stmt->typename);

	baseType = (Form_pg_type) GETSTRUCT(typeTup);
	basetypeoid = HeapTupleGetOid(typeTup);

	/*
	 * Base type must be a plain base type.  Domains over pseudo types would
	 * create a security hole.	Domains of domains might be made to work in
	 * the future, but not today.  Ditto for domains over complex types.
	 */
	typtype = baseType->typtype;
	if (typtype != 'b')
		ereport(ERROR,
				(errcode(ERRCODE_DATATYPE_MISMATCH),
				 errmsg("\"%s\" is not a valid base type for a domain",
						TypeNameToString(stmt->typename))));

	/* passed by value */
	byValue = baseType->typbyval;

	/* Required Alignment */
	alignment = baseType->typalign;

	/* TOAST Strategy */
	storage = baseType->typstorage;

	/* Storage Length */
	internalLength = baseType->typlen;

	/* Array element Delimiter */
	delimiter = baseType->typdelim;

	/* I/O Functions */
	inputProcedure = baseType->typinput;
	outputProcedure = baseType->typoutput;
	receiveProcedure = baseType->typreceive;
	sendProcedure = baseType->typsend;

	/* Analysis function */
	analyzeProcedure = baseType->typanalyze;

	/* Inherited default value */
	datum = SysCacheGetAttr(TYPEOID, typeTup,
							Anum_pg_type_typdefault, &isnull);
	if (!isnull)
		defaultValue = DatumGetCString(DirectFunctionCall1(textout, datum));

	/* Inherited default binary value */
	datum = SysCacheGetAttr(TYPEOID, typeTup,
							Anum_pg_type_typdefaultbin, &isnull);
	if (!isnull)
		defaultValueBin = DatumGetCString(DirectFunctionCall1(textout, datum));

	/*
	 * Pull out the typelem name of the parent OID.
	 *
	 * This is what enables us to make a domain of an array
	 */
	basetypelem = baseType->typelem;

	/*
	 * Run through constraints manually to avoid the additional processing
	 * conducted by DefineRelation() and friends.
	 */
	foreach(listptr, schema)
	{
		Node	   *newConstraint = lfirst(listptr);
		Constraint *constr;
		ParseState *pstate;

		/* 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_DEFAULT:

				/*
				 * The inherited default value may be overridden by the user
				 * with the DEFAULT <expr> statement.
				 */
				if (defaultExpr)
					ereport(ERROR,
							(errcode(ERRCODE_SYNTAX_ERROR),
							 errmsg("multiple default expressions")));

				/* Create a dummy ParseState for transformExpr */
				pstate = make_parsestate(NULL);

				/*
				 * Cook the constr->raw_expr into an expression. Note: Name is
				 * strictly for error message
				 */
				defaultExpr = cookDefault(pstate, constr->raw_expr,
										  basetypeoid,
										  stmt->typename->typmod,
										  domainName);

				/*
				 * 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(domainName,
																  InvalidOid),
												  false, false);
				defaultValueBin = nodeToString(defaultExpr);
				break;

			case CONSTR_NOTNULL:
				if (nullDefined && !typNotNull)
					ereport(ERROR,
							(errcode(ERRCODE_SYNTAX_ERROR),
						   errmsg("conflicting NULL/NOT NULL constraints")));
				typNotNull = true;
				nullDefined = true;
				break;

			case CONSTR_NULL:
				if (nullDefined && typNotNull)
					ereport(ERROR,
							(errcode(ERRCODE_SYNTAX_ERROR),
						   errmsg("conflicting NULL/NOT NULL constraints")));
				typNotNull = false;
				nullDefined = true;
				break;

			case CONSTR_CHECK:

				/*
				 * Check constraints are handled after domain creation, as
				 * they require the Oid of the domain
				 */
				break;

				/*
				 * All else are error cases
				 */
			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;
		}
	}

	/*
	 * Have TypeCreate do all the real work.
	 */
	domainoid =
		TypeCreate(domainName,	/* type name */
				   domainNamespace,		/* namespace */
				   InvalidOid,	/* relation oid (n/a here) */
				   0,			/* relation kind (ditto) */
				   internalLength,		/* internal size */
				   'd',			/* type-type (domain type) */
				   delimiter,	/* array element delimiter */
				   inputProcedure,		/* input procedure */
				   outputProcedure,		/* output procedure */
				   receiveProcedure,	/* receive procedure */
				   sendProcedure,		/* send procedure */
				   analyzeProcedure,	/* analyze procedure */
				   basetypelem, /* element type ID */
				   basetypeoid, /* base type ID */
				   defaultValue,	/* default type value (text) */
				   defaultValueBin,		/* default type value (binary) */
				   byValue,		/* passed by value */
				   alignment,	/* required alignment */
				   storage,		/* TOAST strategy */
				   stmt->typename->typmod,		/* typeMod value */
				   typNDims,	/* Array dimensions for base type */
				   typNotNull); /* Type NOT NULL */

	/*
	 * Process constraints which refer to the domain ID returned by TypeCreate
	 */
	foreach(listptr, schema)
	{
		Constraint *constr = lfirst(listptr);

		/* it must be a Constraint, per check above */

		switch (constr->contype)
		{
			case CONSTR_CHECK:
				domainAddConstraint(domainoid, domainNamespace,
									basetypeoid, stmt->typename->typmod,
									constr, domainName);
				break;

				/* Other constraint types were fully processed above */

			default:
				break;
		}

		/* CCI so we can detect duplicate constraint names */
		CommandCounterIncrement();
	}

	/*
	 * Now we can clean up.
	 */
	ReleaseSysCache(typeTup);
}


/*
 *	RemoveDomain
 *		Removes a domain.
 *
 * This is identical to RemoveType except we insist it be a domain.
 */
void
RemoveDomain(List *names, DropBehavior behavior)
{
	TypeName   *typename;
	Oid			typeoid;
	HeapTuple	tup;
	char		typtype;
	ObjectAddress object;

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

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

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

	/* Permission check: must own type or its namespace */
	if (!pg_type_ownercheck(typeoid, GetUserId()) &&
	  !pg_namespace_ownercheck(((Form_pg_type) GETSTRUCT(tup))->typnamespace,
							   GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TYPE,
					   TypeNameToString(typename));

	/* Check that this is actually a domain */
	typtype = ((Form_pg_type) GETSTRUCT(tup))->typtype;

	if (typtype != 'd')
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is not a domain",
						TypeNameToString(typename))));

	ReleaseSysCache(tup);

	/*
	 * Do the deletion
	 */
	object.classId = TypeRelationId;
	object.objectId = typeoid;
	object.objectSubId = 0;

	performDeletion(&object, behavior);
}


/*
 * Find suitable I/O functions for a type.
 *
 * typeOid is the type's OID (which will already exist, if only as a shell
 * type).
 */

static Oid
findTypeInputFunction(List *procname, Oid typeOid)
{
	Oid			argList[3];
	Oid			procOid;

	/*
	 * Input functions can take a single argument of type CSTRING, or three
	 * arguments (string, typioparam OID, typmod).
	 *
	 * For backwards compatibility we allow OPAQUE in place of CSTRING; if we
	 * see this, we issue a warning and fix up the pg_proc entry.
	 */
	argList[0] = CSTRINGOID;

	procOid = LookupFuncName(procname, 1, argList, true);
	if (OidIsValid(procOid))
		return procOid;

	argList[1] = OIDOID;
	argList[2] = INT4OID;

	procOid = LookupFuncName(procname, 3, argList, true);
	if (OidIsValid(procOid))
		return procOid;

	/* No luck, try it with OPAQUE */
	argList[0] = OPAQUEOID;

	procOid = LookupFuncName(procname, 1, argList, true);

	if (!OidIsValid(procOid))
	{
		argList[1] = OIDOID;
		argList[2] = INT4OID;

		procOid = LookupFuncName(procname, 3, argList, true);
	}

	if (OidIsValid(procOid))
	{
		/* Found, but must complain and fix the pg_proc entry */
		ereport(WARNING,
				(errmsg("changing argument type of function %s from \"opaque\" to \"cstring\"",
						NameListToString(procname))));
		SetFunctionArgType(procOid, 0, CSTRINGOID);

		/*
		 * Need CommandCounterIncrement since DefineType will likely try to
		 * alter the pg_proc tuple again.
		 */
		CommandCounterIncrement();

		return procOid;
	}

	/* Use CSTRING (preferred) in the error message */
	argList[0] = CSTRINGOID;

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

	return InvalidOid;			/* keep compiler quiet */
}

static Oid
findTypeOutputFunction(List *procname, Oid typeOid)
{
	Oid			argList[1];
	Oid			procOid;

	/*
	 * Output functions can take a single argument of the type.