regproc.c

postgresql8.3.4源码,开源数据库

/*-------------------------------------------------------------------------
 *
 * regproc.c
 *	  Functions for the built-in types regproc, regclass, regtype, etc.
 *
 * These types are all binary-compatible with type Oid, and rely on Oid
 * for comparison and so forth.  Their only interesting behavior is in
 * special I/O conversion routines.
 *
 *
 * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/backend/utils/adt/regproc.c,v 1.105 2008/01/01 19:45:52 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include <ctype.h>

#include "access/genam.h"
#include "access/heapam.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_ts_config.h"
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"

static void parseNameAndArgTypes(const char *string, bool allowNone,
					 List **names, int *nargs, Oid *argtypes);


/*****************************************************************************
 *	 USER I/O ROUTINES														 *
 *****************************************************************************/

/*
 * regprocin		- converts "proname" to proc OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_proc entry.
 */
Datum
regprocin(PG_FUNCTION_ARGS)
{
	char	   *pro_name_or_oid = PG_GETARG_CSTRING(0);
	RegProcedure result = InvalidOid;
	List	   *names;
	FuncCandidateList clist;

	/* '-' ? */
	if (strcmp(pro_name_or_oid, "-") == 0)
		PG_RETURN_OID(InvalidOid);

	/* Numeric OID? */
	if (pro_name_or_oid[0] >= '0' &&
		pro_name_or_oid[0] <= '9' &&
		strspn(pro_name_or_oid, "0123456789") == strlen(pro_name_or_oid))
	{
		result = DatumGetObjectId(DirectFunctionCall1(oidin,
										  CStringGetDatum(pro_name_or_oid)));
		PG_RETURN_OID(result);
	}

	/* Else it's a name, possibly schema-qualified */

	/*
	 * In bootstrap mode we assume the given name is not schema-qualified, and
	 * just search pg_proc for a unique match.	This is needed for
	 * initializing other system catalogs (pg_namespace may not exist yet, and
	 * certainly there are no schemas other than pg_catalog).
	 */
	if (IsBootstrapProcessingMode())
	{
		int			matches = 0;
		Relation	hdesc;
		ScanKeyData skey[1];
		SysScanDesc sysscan;
		HeapTuple	tuple;

		ScanKeyInit(&skey[0],
					Anum_pg_proc_proname,
					BTEqualStrategyNumber, F_NAMEEQ,
					CStringGetDatum(pro_name_or_oid));

		hdesc = heap_open(ProcedureRelationId, AccessShareLock);
		sysscan = systable_beginscan(hdesc, ProcedureNameArgsNspIndexId, true,
									 SnapshotNow, 1, skey);

		while (HeapTupleIsValid(tuple = systable_getnext(sysscan)))
		{
			result = (RegProcedure) HeapTupleGetOid(tuple);
			if (++matches > 1)
				break;
		}

		systable_endscan(sysscan);
		heap_close(hdesc, AccessShareLock);

		if (matches == 0)
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("function \"%s\" does not exist", pro_name_or_oid)));

		else if (matches > 1)
			ereport(ERROR,
					(errcode(ERRCODE_AMBIGUOUS_FUNCTION),
					 errmsg("more than one function named \"%s\"",
							pro_name_or_oid)));

		PG_RETURN_OID(result);
	}

	/*
	 * Normal case: parse the name into components and see if it matches any
	 * pg_proc entries in the current search path.
	 */
	names = stringToQualifiedNameList(pro_name_or_oid);
	clist = FuncnameGetCandidates(names, -1);

	if (clist == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("function \"%s\" does not exist", pro_name_or_oid)));
	else if (clist->next != NULL)
		ereport(ERROR,
				(errcode(ERRCODE_AMBIGUOUS_FUNCTION),
				 errmsg("more than one function named \"%s\"",
						pro_name_or_oid)));

	result = clist->oid;

	PG_RETURN_OID(result);
}

/*
 * regprocout		- converts proc OID to "pro_name"
 */
Datum
regprocout(PG_FUNCTION_ARGS)
{
	RegProcedure proid = PG_GETARG_OID(0);
	char	   *result;
	HeapTuple	proctup;

	if (proid == InvalidOid)
	{
		result = pstrdup("-");
		PG_RETURN_CSTRING(result);
	}

	proctup = SearchSysCache(PROCOID,
							 ObjectIdGetDatum(proid),
							 0, 0, 0);

	if (HeapTupleIsValid(proctup))
	{
		Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
		char	   *proname = NameStr(procform->proname);

		/*
		 * In bootstrap mode, skip the fancy namespace stuff and just return
		 * the proc name.  (This path is only needed for debugging output
		 * anyway.)
		 */
		if (IsBootstrapProcessingMode())
			result = pstrdup(proname);
		else
		{
			char	   *nspname;
			FuncCandidateList clist;

			/*
			 * Would this proc be found (uniquely!) by regprocin? If not,
			 * qualify it.
			 */
			clist = FuncnameGetCandidates(list_make1(makeString(proname)), -1);
			if (clist != NULL && clist->next == NULL &&
				clist->oid == proid)
				nspname = NULL;
			else
				nspname = get_namespace_name(procform->pronamespace);

			result = quote_qualified_identifier(nspname, proname);
		}

		ReleaseSysCache(proctup);
	}
	else
	{
		/* If OID doesn't match any pg_proc entry, return it numerically */
		result = (char *) palloc(NAMEDATALEN);
		snprintf(result, NAMEDATALEN, "%u", proid);
	}

	PG_RETURN_CSTRING(result);
}

/*
 *		regprocrecv			- converts external binary format to regproc
 */
Datum
regprocrecv(PG_FUNCTION_ARGS)
{
	/* Exactly the same as oidrecv, so share code */
	return oidrecv(fcinfo);
}

/*
 *		regprocsend			- converts regproc to binary format
 */
Datum
regprocsend(PG_FUNCTION_ARGS)
{
	/* Exactly the same as oidsend, so share code */
	return oidsend(fcinfo);
}


/*
 * regprocedurein		- converts "proname(args)" to proc OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_proc entry.
 */
Datum
regprocedurein(PG_FUNCTION_ARGS)
{
	char	   *pro_name_or_oid = PG_GETARG_CSTRING(0);
	RegProcedure result = InvalidOid;
	List	   *names;
	int			nargs;
	Oid			argtypes[FUNC_MAX_ARGS];
	FuncCandidateList clist;

	/* '-' ? */
	if (strcmp(pro_name_or_oid, "-") == 0)
		PG_RETURN_OID(InvalidOid);

	/* Numeric OID? */
	if (pro_name_or_oid[0] >= '0' &&
		pro_name_or_oid[0] <= '9' &&
		strspn(pro_name_or_oid, "0123456789") == strlen(pro_name_or_oid))
	{
		result = DatumGetObjectId(DirectFunctionCall1(oidin,
										  CStringGetDatum(pro_name_or_oid)));
		PG_RETURN_OID(result);
	}

	/*
	 * Else it's a name and arguments.  Parse the name and arguments, look up
	 * potential matches in the current namespace search list, and scan to see
	 * which one exactly matches the given argument types.	(There will not be
	 * more than one match.)
	 *
	 * XXX at present, this code will not work in bootstrap mode, hence this
	 * datatype cannot be used for any system column that needs to receive
	 * data during bootstrap.
	 */
	parseNameAndArgTypes(pro_name_or_oid, false, &names, &nargs, argtypes);

	clist = FuncnameGetCandidates(names, nargs);

	for (; clist; clist = clist->next)
	{
		if (memcmp(clist->args, argtypes, nargs * sizeof(Oid)) == 0)
			break;
	}

	if (clist == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("function \"%s\" does not exist", pro_name_or_oid)));

	result = clist->oid;

	PG_RETURN_OID(result);
}

/*
 * format_procedure		- converts proc OID to "pro_name(args)"
 *
 * This exports the useful functionality of regprocedureout for use
 * in other backend modules.  The result is a palloc'd string.
 */
char *
format_procedure(Oid procedure_oid)
{
	char	   *result;
	HeapTuple	proctup;

	proctup = SearchSysCache(PROCOID,
							 ObjectIdGetDatum(procedure_oid),
							 0, 0, 0);

	if (HeapTupleIsValid(proctup))
	{
		Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
		char	   *proname = NameStr(procform->proname);
		int			nargs = procform->pronargs;
		int			i;
		char	   *nspname;
		StringInfoData buf;

		/* XXX no support here for bootstrap mode */

		initStringInfo(&buf);

		/*
		 * Would this proc be found (given the right args) by regprocedurein?
		 * If not, we need to qualify it.
		 */
		if (FunctionIsVisible(procedure_oid))
			nspname = NULL;
		else
			nspname = get_namespace_name(procform->pronamespace);

		appendStringInfo(&buf, "%s(",
						 quote_qualified_identifier(nspname, proname));
		for (i = 0; i < nargs; i++)
		{
			Oid			thisargtype = procform->proargtypes.values[i];

			if (i > 0)
				appendStringInfoChar(&buf, ',');
			appendStringInfoString(&buf, format_type_be(thisargtype));
		}
		appendStringInfoChar(&buf, ')');

		result = buf.data;

		ReleaseSysCache(proctup);
	}
	else
	{
		/* If OID doesn't match any pg_proc entry, return it numerically */
		result = (char *) palloc(NAMEDATALEN);
		snprintf(result, NAMEDATALEN, "%u", procedure_oid);
	}

	return result;
}

/*
 * regprocedureout		- converts proc OID to "pro_name(args)"
 */
Datum
regprocedureout(PG_FUNCTION_ARGS)
{
	RegProcedure proid = PG_GETARG_OID(0);
	char	   *result;

	if (proid == InvalidOid)
		result = pstrdup("-");
	else
		result = format_procedure(proid);

	PG_RETURN_CSTRING(result);
}

/*
 *		regprocedurerecv			- converts external binary format to regprocedure
 */
Datum
regprocedurerecv(PG_FUNCTION_ARGS)
{
	/* Exactly the same as oidrecv, so share code */
	return oidrecv(fcinfo);
}

/*
 *		regproceduresend			- converts regprocedure to binary format
 */
Datum
regproceduresend(PG_FUNCTION_ARGS)
{
	/* Exactly the same as oidsend, so share code */
	return oidsend(fcinfo);
}


/*
 * regoperin		- converts "oprname" to operator OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '0' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_operator entry.
 */
Datum
regoperin(PG_FUNCTION_ARGS)
{
	char	   *opr_name_or_oid = PG_GETARG_CSTRING(0);
	Oid			result = InvalidOid;
	List	   *names;
	FuncCandidateList clist;

	/* '0' ? */
	if (strcmp(opr_name_or_oid, "0") == 0)
		PG_RETURN_OID(InvalidOid);

	/* Numeric OID? */
	if (opr_name_or_oid[0] >= '0' &&
		opr_name_or_oid[0] <= '9' &&
		strspn(opr_name_or_oid, "0123456789") == strlen(opr_name_or_oid))
	{
		result = DatumGetObjectId(DirectFunctionCall1(oidin,
										  CStringGetDatum(opr_name_or_oid)));
		PG_RETURN_OID(result);
	}

	/* Else it's a name, possibly schema-qualified */

	/*
	 * In bootstrap mode we assume the given name is not schema-qualified, and
	 * just search pg_operator for a unique match.	This is needed for
	 * initializing other system catalogs (pg_namespace may not exist yet, and
	 * certainly there are no schemas other than pg_catalog).
	 */
	if (IsBootstrapProcessingMode())
	{
		int			matches = 0;
		Relation	hdesc;
		ScanKeyData skey[1];
		SysScanDesc sysscan;
		HeapTuple	tuple;

		ScanKeyInit(&skey[0],
					Anum_pg_operator_oprname,
					BTEqualStrategyNumber, F_NAMEEQ,
					CStringGetDatum(opr_name_or_oid));

		hdesc = heap_open(OperatorRelationId, AccessShareLock);
		sysscan = systable_beginscan(hdesc, OperatorNameNspIndexId, true,
									 SnapshotNow, 1, skey);

		while (HeapTupleIsValid(tuple = systable_getnext(sysscan)))
		{
			result = HeapTupleGetOid(tuple);
			if (++matches > 1)
				break;
		}

		systable_endscan(sysscan);
		heap_close(hdesc, AccessShareLock);

		if (matches == 0)
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_FUNCTION),
					 errmsg("operator does not exist: %s", opr_name_or_oid)));
		else if (matches > 1)
			ereport(ERROR,
					(errcode(ERRCODE_AMBIGUOUS_FUNCTION),
					 errmsg("more than one operator named %s",
							opr_name_or_oid)));

		PG_RETURN_OID(result);
	}

	/*
	 * Normal case: parse the name into components and see if it matches any
	 * pg_operator entries in the current search path.
	 */
	names = stringToQualifiedNameList(opr_name_or_oid);
	clist = OpernameGetCandidates(names, '\0');

	if (clist == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_FUNCTION),
				 errmsg("operator does not exist: %s", opr_name_or_oid)));
	else if (clist->next != NULL)
		ereport(ERROR,
				(errcode(ERRCODE_AMBIGUOUS_FUNCTION),
				 errmsg("more than one operator named %s",
						opr_name_or_oid)));

	result = clist->oid;

	PG_RETURN_OID(result);
}

/*
 * regoperout		- converts operator OID to "opr_name"
 */
Datum
regoperout(PG_FUNCTION_ARGS)
{