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/*-------------------------------------------------------------------------
*
* catalog.c
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/catalog/catalog.c,v 1.39 2001/01/24 19:42:51 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/transam.h"
#include "catalog/catalog.h"
#include "catalog/catname.h"
#include "catalog/pg_type.h"
#include "miscadmin.h"
#include "utils/lsyscache.h"
#ifdef OLD_FILE_NAMING
/*
* relpath - construct path to a relation's file
*
* Note that this only works with relations that are visible to the current
* backend, ie, either in the current database or shared system relations.
*
* Result is a palloc'd string.
*/
char *
relpath(const char *relname)
{
char *path;
if (IsSharedSystemRelationName(relname))
{
/* Shared system relations live in {datadir}/global */
size_t bufsize = strlen(DataDir) + 8 + sizeof(NameData) + 1;
path = (char *) palloc(bufsize);
snprintf(path, bufsize, "%s/global/%s", DataDir, relname);
return path;
}
/*
* If it is in the current database, assume it is in current working
* directory. NB: this does not work during bootstrap!
*/
return pstrdup(relname);
}
/*
* relpath_blind - construct path to a relation's file
*
* Construct the path using only the info available to smgrblindwrt,
* namely the names and OIDs of the database and relation. (Shared system
* relations are identified with dbid = 0.) Note that we may have to
* access a relation belonging to a different database!
*
* Result is a palloc'd string.
*/
char *
relpath_blind(const char *dbname, const char *relname,
Oid dbid, Oid relid)
{
char *path;
if (dbid == (Oid) 0)
{
/* Shared system relations live in {datadir}/global */
path = (char *) palloc(strlen(DataDir) + 8 + sizeof(NameData) + 1);
sprintf(path, "%s/global/%s", DataDir, relname);
}
else if (dbid == MyDatabaseId)
{
/* XXX why is this inconsistent with relpath() ? */
path = (char *) palloc(strlen(DatabasePath) + sizeof(NameData) + 2);
sprintf(path, "%s%c%s", DatabasePath, SEP_CHAR, relname);
}
else
{
/* this is work around only !!! */
char dbpathtmp[MAXPGPATH];
Oid id;
char *dbpath;
GetRawDatabaseInfo(dbname, &id, dbpathtmp);
if (id != dbid)
elog(FATAL, "relpath_blind: oid of db %s is not %u",
dbname, dbid);
dbpath = ExpandDatabasePath(dbpathtmp);
if (dbpath == NULL)
elog(FATAL, "relpath_blind: can't expand path for db %s",
dbname);
path = (char *) palloc(strlen(dbpath) + sizeof(NameData) + 2);
sprintf(path, "%s%c%s", dbpath, SEP_CHAR, relname);
pfree(dbpath);
}
return path;
}
#else /* ! OLD_FILE_NAMING */
/*
* relpath - construct path to a relation's file
*
* Result is a palloc'd string.
*/
char *
relpath(RelFileNode rnode)
{
char *path;
if (rnode.tblNode == (Oid) 0) /* "global tablespace" */
{
/* Shared system relations live in {datadir}/global */
path = (char *) palloc(strlen(DataDir) + 8 + sizeof(NameData) + 1);
sprintf(path, "%s%cglobal%c%u", DataDir, SEP_CHAR, SEP_CHAR, rnode.relNode);
}
else
{
path = (char *) palloc(strlen(DataDir) + 6 + 2 * sizeof(NameData) + 3);
sprintf(path, "%s%cbase%c%u%c%u", DataDir, SEP_CHAR, SEP_CHAR,
rnode.tblNode, SEP_CHAR, rnode.relNode);
}
return path;
}
/*
* GetDatabasePath - construct path to a database dir
*
* Result is a palloc'd string.
*/
char *
GetDatabasePath(Oid tblNode)
{
char *path;
if (tblNode == (Oid) 0) /* "global tablespace" */
{
/* Shared system relations live in {datadir}/global */
path = (char *) palloc(strlen(DataDir) + 8);
sprintf(path, "%s%cglobal", DataDir, SEP_CHAR);
}
else
{
path = (char *) palloc(strlen(DataDir) + 6 + sizeof(NameData) + 1);
sprintf(path, "%s%cbase%c%u", DataDir, SEP_CHAR, SEP_CHAR, tblNode);
}
return path;
}
#endif /* OLD_FILE_NAMING */
/*
* IsSystemRelationName
* True iff name is the name of a system catalog relation.
*
* We now make a new requirement where system catalog relns must begin
* with pg_ while user relns are forbidden to do so. Make the test
* trivial and instantaneous.
*
* XXX this is way bogus. -- pma
*/
bool
IsSystemRelationName(const char *relname)
{
if (relname[0] && relname[1] && relname[2])
return (relname[0] == 'p' &&
relname[1] == 'g' &&
relname[2] == '_');
else
return FALSE;
}
/*
* IsSharedSystemRelationName
* True iff name is the name of a shared system catalog relation.
*/
bool
IsSharedSystemRelationName(const char *relname)
{
int i;
/*
* Quick out: if it's not a system relation, it can't be a shared
* system relation.
*/
if (!IsSystemRelationName(relname))
return FALSE;
i = 0;
while (SharedSystemRelationNames[i] != NULL)
{
if (strcmp(SharedSystemRelationNames[i], relname) == 0)
return TRUE;
i++;
}
return FALSE;
}
/*
* newoid - returns a unique identifier across all catalogs.
*
* Object Id allocation is now done by GetNewObjectID in
* access/transam/varsup.c. oids are now allocated correctly.
*
* old comments:
* This needs to change soon, it fails if there are too many more
* than one call per second when postgres restarts after it dies.
*
* The distribution of OID's should be done by the POSTMASTER.
* Also there needs to be a facility to preallocate OID's. Ie.,
* for a block of OID's to be declared as invalid ones to allow
* user programs to use them for temporary object identifiers.
*/
Oid
newoid(void)
{
Oid lastoid;
GetNewObjectId(&lastoid);
if (!OidIsValid(lastoid))
elog(ERROR, "newoid: GetNewObjectId returns invalid oid");
return lastoid;
}
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