postgresql/src/backend/commands/typecmds.c

/*-------------------------------------------------------------------------
 *
 * typecmds.c
 *	  Routines for SQL commands that manipulate types (and domains).
 *
 * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/backend/commands/typecmds.c,v 1.1 2002/04/15 05:22:03 tgl Exp $
 *
 * DESCRIPTION
 *	  The "DefineFoo" routines take the parse tree and pick out the
 *	  appropriate arguments/flags, passing the results to the
 *	  corresponding "FooDefine" routines (in src/catalog) that do
 *	  the actual catalog-munging.  These routines also verify permission
 *	  of the user to execute the command.
 *
 * NOTES
 *	  These things must be defined and committed in the following order:
 *		"create function":
 *				input/output, recv/send procedures
 *		"create type":
 *				type
 *		"create operator":
 *				operators
 *
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/heap.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "miscadmin.h"
#include "parser/parse.h"
#include "parser/parse_func.h"
#include "parser/parse_type.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/syscache.h"


static Oid findTypeIOFunction(List *procname, bool isOutput);


/*
 * DefineType
 *		Registers a new type.
 */
void
DefineType(List *names, List *parameters)
{
	char	   *typeName;
	Oid			typeNamespace;
	int16		internalLength = -1;	/* int2 */
	int16		externalLength = -1;	/* int2 */
	Oid			elemType = InvalidOid;
	List	   *inputName = NIL;
	List	   *outputName = NIL;
	List	   *sendName = NIL;
	List	   *receiveName = NIL;
	char	   *defaultValue = NULL;
	bool		byValue = false;
	char		delimiter = DEFAULT_TYPDELIM;
	char		alignment = 'i';	/* default alignment */
	char		storage = 'p';	/* default TOAST storage method */
	Oid			inputOid;
	Oid			outputOid;
	Oid			sendOid;
	Oid			receiveOid;
	char	   *shadow_type;
	List	   *pl;
	Oid			typoid;

	/* Convert list of names to a name and namespace */
	typeNamespace = QualifiedNameGetCreationNamespace(names, &typeName);

	/*
	 * Type names must be one character shorter than other names, allowing
	 * room to create the corresponding array type name with prepended
	 * "_".
	 */
	if (strlen(typeName) > (NAMEDATALEN - 2))
		elog(ERROR, "DefineType: type names must be %d characters or less",
			 NAMEDATALEN - 2);

	foreach(pl, parameters)
	{
		DefElem    *defel = (DefElem *) lfirst(pl);

		if (strcasecmp(defel->defname, "internallength") == 0)
			internalLength = defGetTypeLength(defel);
		else if (strcasecmp(defel->defname, "externallength") == 0)
			externalLength = defGetTypeLength(defel);
		else if (strcasecmp(defel->defname, "input") == 0)
			inputName = defGetQualifiedName(defel);
		else if (strcasecmp(defel->defname, "output") == 0)
			outputName = defGetQualifiedName(defel);
		else if (strcasecmp(defel->defname, "send") == 0)
			sendName = defGetQualifiedName(defel);
		else if (strcasecmp(defel->defname, "receive") == 0)
			receiveName = defGetQualifiedName(defel);
		else if (strcasecmp(defel->defname, "delimiter") == 0)
		{
			char	   *p = defGetString(defel);

			delimiter = p[0];
		}
		else if (strcasecmp(defel->defname, "element") == 0)
			elemType = typenameTypeId(defGetTypeName(defel));
		else if (strcasecmp(defel->defname, "default") == 0)
			defaultValue = defGetString(defel);
		else if (strcasecmp(defel->defname, "passedbyvalue") == 0)
			byValue = true;
		else if (strcasecmp(defel->defname, "alignment") == 0)
		{
			char	   *a = defGetString(defel);

			/*
			 * Note: if argument was an unquoted identifier, parser will
			 * have applied xlateSqlType() to it, so be prepared to
			 * recognize translated type names as well as the nominal
			 * form.
			 */
			if (strcasecmp(a, "double") == 0)
				alignment = 'd';
			else if (strcasecmp(a, "float8") == 0)
				alignment = 'd';
			else if (strcasecmp(a, "int4") == 0)
				alignment = 'i';
			else if (strcasecmp(a, "int2") == 0)
				alignment = 's';
			else if (strcasecmp(a, "char") == 0)
				alignment = 'c';
			else if (strcasecmp(a, "bpchar") == 0)
				alignment = 'c';
			else
				elog(ERROR, "DefineType: \"%s\" alignment not recognized",
					 a);
		}
		else if (strcasecmp(defel->defname, "storage") == 0)
		{
			char	   *a = defGetString(defel);

			if (strcasecmp(a, "plain") == 0)
				storage = 'p';
			else if (strcasecmp(a, "external") == 0)
				storage = 'e';
			else if (strcasecmp(a, "extended") == 0)
				storage = 'x';
			else if (strcasecmp(a, "main") == 0)
				storage = 'm';
			else
				elog(ERROR, "DefineType: \"%s\" storage not recognized",
					 a);
		}
		else
		{
			elog(WARNING, "DefineType: attribute \"%s\" not recognized",
				 defel->defname);
		}
	}

	/*
	 * make sure we have our required definitions
	 */
	if (inputName == NIL)
		elog(ERROR, "Define: \"input\" unspecified");
	if (outputName == NIL)
		elog(ERROR, "Define: \"output\" unspecified");

	/* Convert I/O proc names to OIDs */
	inputOid = findTypeIOFunction(inputName, false);
	outputOid = findTypeIOFunction(outputName, true);
	if (sendName)
		sendOid = findTypeIOFunction(sendName, true);
	else
		sendOid = outputOid;
	if (receiveName)
		receiveOid = findTypeIOFunction(receiveName, false);
	else
		receiveOid = inputOid;

	/*
	 * now have TypeCreate do all the real work.
	 */
	typoid =
		TypeCreate(typeName,		/* type name */
				   typeNamespace,	/* namespace */
				   InvalidOid,		/* preassigned type oid (not done here) */
				   InvalidOid,		/* relation oid (n/a here) */
				   internalLength,	/* internal size */
				   externalLength,	/* external size */
				   'b',				/* type-type (base type) */
				   delimiter,		/* array element delimiter */
				   inputOid,		/* input procedure */
				   outputOid,		/* output procedure */
				   receiveOid,		/* receive procedure */
				   sendOid,			/* send procedure */
				   elemType,		/* element type ID */
				   InvalidOid,		/* base type ID (only for domains) */
				   defaultValue,	/* default type value */
				   NULL,			/* no binary form available */
				   byValue,			/* passed by value */
				   alignment,		/* required alignment */
				   storage,			/* TOAST strategy */
				   -1,				/* typMod (Domains only) */
				   0,				/* Array Dimensions of typbasetype */
				   false);			/* Type NOT NULL */

	/*
	 * When we create a base type (as opposed to a complex type) we need
	 * to have an array entry for it in pg_type as well.
	 */
	shadow_type = makeArrayTypeName(typeName);

	/* alignment must be 'i' or 'd' for arrays */
	alignment = (alignment == 'd') ? 'd' : 'i';

	TypeCreate(shadow_type,		/* type name */
			   typeNamespace,	/* namespace */
			   InvalidOid,		/* preassigned type oid (not done here) */
			   InvalidOid,		/* relation oid (n/a here) */
			   -1,				/* internal size */
			   -1,				/* external size */
			   'b',				/* type-type (base type) */
			   DEFAULT_TYPDELIM,	/* array element delimiter */
			   F_ARRAY_IN,		/* input procedure */
			   F_ARRAY_OUT,		/* output procedure */
			   F_ARRAY_IN,		/* receive procedure */
			   F_ARRAY_OUT,		/* send procedure */
			   typoid,			/* element type ID */
			   InvalidOid,		/* base type ID */
			   NULL,			/* never a default type value */
			   NULL,			/* binary default isn't sent either */
			   false,			/* never passed by value */
			   alignment,		/* see above */
			   'x',				/* ARRAY is always toastable */
			   -1,				/* typMod (Domains only) */
			   0,				/* Array dimensions of typbasetype */
			   false);			/* Type NOT NULL */

	pfree(shadow_type);
}


/*
 *	RemoveType
 *		Removes a datatype.
 *
 * NOTE: since this tries to remove the associated array type too, it'll
 * only work on scalar types.
 */
void
RemoveType(List *names)
{
	TypeName   *typename;
	Relation	relation;
	Oid			typeoid;
	HeapTuple	tup;

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

	relation = heap_openr(TypeRelationName, RowExclusiveLock);

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

	tup = SearchSysCache(TYPEOID,
						 ObjectIdGetDatum(typeoid),
						 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "Type \"%s\" does not exist",
			 TypeNameToString(typename));

	if (!pg_type_ownercheck(typeoid, GetUserId()))
		elog(ERROR, "RemoveType: type '%s': permission denied",
			 TypeNameToString(typename));

	/* Delete any comments associated with this type */
	DeleteComments(typeoid, RelationGetRelid(relation));

	/* Remove the type tuple from pg_type */
	simple_heap_delete(relation, &tup->t_self);

	ReleaseSysCache(tup);

	/* Now, delete the "array of" that type */
	typename->arrayBounds = makeList1(makeInteger(1));

	typeoid = LookupTypeName(typename);
	if (!OidIsValid(typeoid))
		elog(ERROR, "Type \"%s\" does not exist",
			 TypeNameToString(typename));

	tup = SearchSysCache(TYPEOID,
						 ObjectIdGetDatum(typeoid),
						 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "Type \"%s\" does not exist",
			 TypeNameToString(typename));

	DeleteComments(typeoid, RelationGetRelid(relation));

	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;
	int16		internalLength;
	int16		externalLength;
	Oid			inputProcedure;
	Oid			outputProcedure;
	Oid			receiveProcedure;
	Oid			sendProcedure;
	bool		byValue;
	char		delimiter;
	char		alignment;
	char		storage;
	char		typtype;
	Datum		datum;
	bool		isnull;
	char	   *defaultValue = NULL;
	char	   *defaultValueBin = NULL;
	bool		typNotNull = false;
	Oid			basetypelem;
	int32		typNDims = length(stmt->typename->arrayBounds);
	HeapTuple	typeTup;
	List	   *schema = stmt->constraints;
	List	   *listptr;

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

	/*
	 * Domainnames, unlike typenames don't need to account for the '_'
	 * prefix.  So they can be one character longer.
	 */
	if (strlen(domainName) > (NAMEDATALEN - 1))
		elog(ERROR, "CREATE DOMAIN: domain names must be %d characters or less",
			 NAMEDATALEN - 1);

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

	/*
	 * What we really don't want is domains of domains.  This could cause all sorts
	 * of neat issues if we allow that.
	 *
	 * With testing, we may determine complex types should be allowed
	 */
	typtype = ((Form_pg_type) GETSTRUCT(typeTup))->typtype;
	if (typtype != 'b')
		elog(ERROR, "DefineDomain: %s is not a basetype",
			 TypeNameToString(stmt->typename));

	/* passed by value */
	byValue = ((Form_pg_type) GETSTRUCT(typeTup))->typbyval;

	/* Required Alignment */
	alignment = ((Form_pg_type) GETSTRUCT(typeTup))->typalign;

	/* TOAST Strategy */
	storage = ((Form_pg_type) GETSTRUCT(typeTup))->typstorage;

	/* Storage Length */
	internalLength = ((Form_pg_type) GETSTRUCT(typeTup))->typlen;

	/* External Length (unused) */
	externalLength = ((Form_pg_type) GETSTRUCT(typeTup))->typprtlen;

	/* Array element Delimiter */
	delimiter = ((Form_pg_type) GETSTRUCT(typeTup))->typdelim;

	/* I/O Functions */
	inputProcedure = ((Form_pg_type) GETSTRUCT(typeTup))->typinput;
	outputProcedure = ((Form_pg_type) GETSTRUCT(typeTup))->typoutput;
	receiveProcedure = ((Form_pg_type) GETSTRUCT(typeTup))->typreceive;
	sendProcedure = ((Form_pg_type) GETSTRUCT(typeTup))->typsend;

	/* 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 = ((Form_pg_type) GETSTRUCT(typeTup))->typelem;

	/*
	 * Run through constraints manually to avoid the additional
	 * processing conducted by DefineRelation() and friends.
	 *
	 * Besides, we don't want any constraints to be cooked.  We'll
	 * do that when the table is created via MergeDomainAttributes().
	 */
	foreach(listptr, schema)
	{
		Constraint *colDef = lfirst(listptr);
		bool nullDefined = false;
		Node	   *expr;
		ParseState *pstate;

		switch (colDef->contype)
		{
			/*
	 		 * The inherited default value may be overridden by the user
			 * with the DEFAULT <expr> statement.
			 *
	 		 * We have to search the entire constraint tree returned as we
			 * don't want to cook or fiddle too much.
			 */
			case CONSTR_DEFAULT:
				/* 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
				 */
				expr = cookDefault(pstate, colDef->raw_expr,
								   typeTup->t_data->t_oid,
								   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(expr,
								deparse_context_for(domainName,
													InvalidOid),
												   false);
				defaultValueBin = nodeToString(expr);
				break;

			/*
			 * Find the NULL constraint.
			 */
			case CONSTR_NOTNULL:
				if (nullDefined) {
					elog(ERROR, "CREATE DOMAIN has conflicting NULL / NOT NULL constraint");
				} else {
					typNotNull = true;
					nullDefined = true;
				}
		  		break;

			case CONSTR_NULL:
				if (nullDefined) {
					elog(ERROR, "CREATE DOMAIN has conflicting NULL / NOT NULL constraint");
				} else {
					typNotNull = false;
					nullDefined = true;
				}
		  		break;

		  	case CONSTR_UNIQUE:
		  		elog(ERROR, "CREATE DOMAIN / UNIQUE indexes not supported");
		  		break;

		  	case CONSTR_PRIMARY:
		  		elog(ERROR, "CREATE DOMAIN / PRIMARY KEY indexes not supported");
		  		break;

		  	case CONSTR_CHECK:
		  		elog(ERROR, "DefineDomain: CHECK Constraints not supported");
		  		break;

		  	case CONSTR_ATTR_DEFERRABLE:
		  	case CONSTR_ATTR_NOT_DEFERRABLE:
		  	case CONSTR_ATTR_DEFERRED:
		  	case CONSTR_ATTR_IMMEDIATE:
		  		elog(ERROR, "DefineDomain: DEFERRABLE, NON DEFERRABLE, DEFERRED and IMMEDIATE not supported");
		  		break;

			default:
		  		elog(ERROR, "DefineDomain: unrecognized constraint node type");
		  		break;
		}
	}

	/*
	 * Have TypeCreate do all the real work.
	 */
	TypeCreate(domainName,			/* type name */
			   domainNamespace,		/* namespace */
			   InvalidOid,			/* preassigned type oid (not done here) */
			   InvalidOid,			/* relation oid (n/a here) */
			   internalLength,		/* internal size */
			   externalLength,		/* external size */
			   'd',					/* type-type (domain type) */
			   delimiter,			/* array element delimiter */
			   inputProcedure,		/* input procedure */
			   outputProcedure,		/* output procedure */
			   receiveProcedure,	/* receive procedure */
			   sendProcedure,		/* send procedure */
			   basetypelem,			/* element type ID */
			   typeTup->t_data->t_oid,	/* 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 */

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


/*
 *	RemoveDomain
 *		Removes a domain.
 */
void
RemoveDomain(List *names, int behavior)
{
	TypeName   *typename;
	Relation	relation;
	Oid			typeoid;
	HeapTuple	tup;
	char		typtype;

	/* CASCADE unsupported */
	if (behavior == CASCADE)
		elog(ERROR, "DROP DOMAIN does not support the CASCADE keyword");

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

	relation = heap_openr(TypeRelationName, RowExclusiveLock);

	typeoid = typenameTypeId(typename);

	tup = SearchSysCache(TYPEOID,
						 ObjectIdGetDatum(typeoid),
						 0, 0, 0);
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "RemoveDomain: type '%s' does not exist",
			 TypeNameToString(typename));

	if (!pg_type_ownercheck(typeoid, GetUserId()))
		elog(ERROR, "RemoveDomain: type '%s': permission denied",
			 TypeNameToString(typename));

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

	if (typtype != 'd')
		elog(ERROR, "%s is not a domain",
			 TypeNameToString(typename));

	/* Delete any comments associated with this type */
	DeleteComments(typeoid, RelationGetRelid(relation));

	/* Remove the type tuple from pg_type */
	simple_heap_delete(relation, &tup->t_self);

	ReleaseSysCache(tup);

	/* At present, domains don't have associated array types */

	heap_close(relation, RowExclusiveLock);
}


/*
 * Find a suitable I/O function for a type.
 */
static Oid
findTypeIOFunction(List *procname, bool isOutput)
{
	Oid			argList[FUNC_MAX_ARGS];
	int			nargs;
	Oid			procOid;

	/*
	 * First look for a 1-argument func with all argtypes 0. This is
	 * valid for all kinds of procedure.
	 */
	MemSet(argList, 0, FUNC_MAX_ARGS * sizeof(Oid));

	procOid = LookupFuncName(procname, 1, argList);

	if (!OidIsValid(procOid))
	{
		/*
		 * Alternatively, input procedures may take 3 args (data
		 * value, element OID, atttypmod); the pg_proc argtype
		 * signature is 0,OIDOID,INT4OID.  Output procedures may
		 * take 2 args (data value, element OID).
		 */
		if (isOutput)
		{
			/* output proc */
			nargs = 2;
			argList[1] = OIDOID;
		}
		else
		{
			/* input proc */
			nargs = 3;
			argList[1] = OIDOID;
			argList[2] = INT4OID;
		}
		procOid = LookupFuncName(procname, nargs, argList);

		if (!OidIsValid(procOid))
			func_error("TypeCreate", procname, 1, argList, NULL);
	}

	return procOid;
}