--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * database.c--
+ * miscellanious initialization support stuff
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * $Header: /cvsroot/pgsql/src/backend/utils/misc/Attic/database.c,v 1.1 1997/11/07 07:05:46 thomas Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include
+#include
+#include
+#include
+#include
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "utils/elog.h"
+#include "utils/builtins.h"
+#include "utils/syscache.h"
+
+#include "access/heapam.h"
+#include "storage/bufmgr.h"
+#include "catalog/catname.h"
+#include "catalog/pg_proc.h"
+#include "catalog/pg_database.h"
+
+#include "access/xact.h"
+#include "storage/bufpage.h"
+
+/* GetDatabaseInfo()
+ * Pull database information from pg_database.
+ */
+int
+GetDatabaseInfo(char *name, Oid *owner, char *path)
+{
+ Oid dbowner,
+ dbid;
+ char dbpath[MAXPGPATH+1];
+ text *dbtext;
+
+ Relation dbrel;
+ HeapTuple dbtup;
+ HeapTuple tup;
+ Buffer buf;
+ HeapScanDesc scan;
+ ScanKeyData scanKey;
+
+ dbrel = heap_openr(DatabaseRelationName);
+ if (!RelationIsValid(dbrel))
+ elog(FATAL,"GetDatabaseInfo: cannot open relation \"%-.*s\"",
+ DatabaseRelationName);
+
+ ScanKeyEntryInitialize(&scanKey, 0, Anum_pg_database_datname,
+ NameEqualRegProcedure, NameGetDatum(name));
+
+ scan = heap_beginscan(dbrel, 0, NowTimeQual, 1, &scanKey);
+ if (!HeapScanIsValid(scan))
+ elog(WARN, "GetDatabaseInfo: cannot begin scan of %s", DatabaseRelationName);
+
+ /*
+ * Since we're going to close the relation, copy the tuple.
+ */
+ tup = heap_getnext(scan, 0, &buf);
+
+ if (HeapTupleIsValid(tup))
+ {
+ dbtup = heap_copytuple(tup);
+ ReleaseBuffer(buf);
+ }
+ else
+ dbtup = tup;
+
+ heap_endscan(scan);
+
+ if (!HeapTupleIsValid(dbtup))
+ {
+ elog(NOTICE,"GetDatabaseInfo: %s entry not found %s",
+ DatabaseRelationName,name);
+ return TRUE;
+ }
+
+ dbowner = (Oid) heap_getattr(dbtup, InvalidBuffer,
+ Anum_pg_database_datdba,
+ RelationGetTupleDescriptor(dbrel),
+ (char *) NULL);
+ dbid = dbtup->t_oid;
+
+ dbtext = (text *) heap_getattr(dbtup, InvalidBuffer,
+ Anum_pg_database_datpath,
+ RelationGetTupleDescriptor(dbrel),
+ (char *) NULL);
+
+ memcpy(dbpath, VARDATA(dbtext), (VARSIZE(dbtext)-VARHDRSZ));
+ *(dbpath+(VARSIZE(dbtext)-VARHDRSZ)) = '\0';
+
+ heap_close(dbrel);
+
+ owner = palloc(sizeof(Oid));
+ *owner = dbowner;
+ path = palloc(strlen(dbpath)+1);
+ strcpy(path, dbpath);
+
+ return FALSE;
+} /* GetDatabaseInfo() */
+
+char *
+ExpandDatabasePath(char *dbpath)
+{
+ char *path;
+ char *cp;
+ char buf[MAXPGPATH+1];
+
+ /* leading path delimiter? then already absolute path */
+ if (*dbpath == SEP_CHAR)
+ {
+ cp = strrchr(dbpath, SEP_CHAR);
+ strncpy(buf,dbpath,(cp-dbpath));
+ sprintf(&buf[cp-dbpath], "%cbase%c%s", SEP_CHAR, SEP_CHAR, (cp+1));
+ }
+ /* path delimiter somewhere? then has leading environment variable */
+ else if (strchr(dbpath, SEP_CHAR) != NULL)
+ {
+ cp = strchr(dbpath, SEP_CHAR);
+ strncpy(buf,dbpath,(cp-dbpath));
+ buf[cp-dbpath] = '\0';
+ path = getenv(buf);
+ sprintf(buf, "%s%cbase%c%s", path, SEP_CHAR, SEP_CHAR, (cp+1));
+ }
+ /* no path delimiter? then add the default path prefixes */
+ else
+ {
+ sprintf(buf, "%s%cbase%c%s", DataDir, SEP_CHAR, SEP_CHAR, dbpath);
+ }
+
+ path = palloc(strlen(buf)+1);
+ strcpy(path,buf);
+
+ return path;
+} /* ExpandDatabasePath() */
+
+
+/* --------------------------------
+ * GetRawDatabaseInfo() -- Find the OID and path of the database.
+ *
+ * The database's oid forms half of the unique key for the system
+ * caches and lock tables. We therefore want it initialized before
+ * we open any relations, since opening relations puts things in the
+ * cache. To get around this problem, this code opens and scans the
+ * pg_database relation by hand.
+ *
+ * This algorithm relies on the fact that first attribute in the
+ * pg_database relation schema is the database name. It also knows
+ * about the internal format of tuples on disk and the length of
+ * the datname attribute. It knows the location of the pg_database
+ * file.
+ * Actually, the code looks as though it is using the pg_database
+ * tuple definition to locate the database name, so the above statement
+ * seems to be no longer correct. - thomas 1997-11-01
+ *
+ * This code is called from InitPostgres(), before we chdir() to the
+ * local database directory and before we open any relations.
+ * Used to be called after the chdir(), but we now want to confirm
+ * the location of the target database using pg_database info.
+ * - thomas 1997-11-01
+ * --------------------------------
+ */
+void
+GetRawDatabaseInfo(char *name, Oid *owner, Oid *db_id, char *path)
+{
+ int dbfd;
+ int fileflags;
+ int nbytes;
+ int max,
+ i;
+ HeapTuple tup;
+ Page pg;
+ PageHeader ph;
+ char *dbfname;
+ Form_pg_database tup_db;
+
+ dbfname = (char *) palloc(strlen(DataDir) + strlen("pg_database") + 2);
+ sprintf(dbfname, "%s%cpg_database", DataDir, SEP_CHAR);
+ fileflags = O_RDONLY;
+
+ if ((dbfd = open(dbfname, O_RDONLY, 0)) < 0)
+ elog(FATAL, "Cannot open %s", dbfname);
+
+ pfree(dbfname);
+
+ /* ----------------
+ * read and examine every page in pg_database
+ *
+ * Raw I/O! Read those tuples the hard way! Yow!
+ *
+ * Why don't we use the access methods or move this code
+ * someplace else? This is really pg_database schema dependent
+ * code. Perhaps it should go in lib/catalog/pg_database?
+ * -cim 10/3/90
+ *
+ * mao replies 4 apr 91: yeah, maybe this should be moved to
+ * lib/catalog. however, we CANNOT use the access methods since
+ * those use the buffer cache, which uses the relation cache, which
+ * requires that the dbid be set, which is what we're trying to do
+ * here.
+ * ----------------
+ */
+ pg = (Page) palloc(BLCKSZ);
+ ph = (PageHeader) pg;
+
+ while ((nbytes = read(dbfd, pg, BLCKSZ)) == BLCKSZ)
+ {
+ max = PageGetMaxOffsetNumber(pg);
+
+ /* look at each tuple on the page */
+ for (i = 0; i <= max; i++)
+ {
+ int offset;
+
+ /* if it's a freed tuple, ignore it */
+ if (!(ph->pd_linp[i].lp_flags & LP_USED))
+ continue;
+
+ /* get a pointer to the tuple itself */
+ offset = (int) ph->pd_linp[i].lp_off;
+ tup = (HeapTuple) (((char *) pg) + offset);
+
+ /*
+ * if the tuple has been deleted (the database was destroyed),
+ * skip this tuple. XXX warning, will robinson: violation of
+ * transaction semantics happens right here. we should check
+ * to be sure that the xact that deleted this tuple actually
+ * committed. only way to do this at init time is to paw over
+ * the log relation by hand, too. let's be optimistic.
+ *
+ * XXX This is an evil type cast. tup->t_xmax is char[5] while
+ * TransactionId is struct * { char data[5] }. It works but
+ * if data is ever moved and no longer the first field this
+ * will be broken!! -mer 11 Nov 1991.
+ */
+ if (TransactionIdIsValid((TransactionId) tup->t_xmax))
+ continue;
+
+ /*
+ * Okay, see if this is the one we want. XXX 1 july 91: mao
+ * and mer discover that tuples now squash t_bits. Why is
+ * this?
+ *
+ * 24 july 92: mer realizes that the t_bits field is only used
+ * in the event of null values. If no fields are null we
+ * reduce the header size by doing the squash. t_hoff tells
+ * you exactly how big the header actually is. use the PC
+ * means of getting at sys cat attrs.
+ */
+ tup_db = (Form_pg_database) GETSTRUCT(tup);
+
+ if (strncmp(name,
+ &(tup_db->datname.data[0]),
+ 16) == 0)
+ {
+ *db_id = tup->t_oid;
+ strncpy(path, VARDATA(&(tup_db->datpath)),
+ (VARSIZE(&(tup_db->datpath))-VARHDRSZ));
+ *(path+VARSIZE(&(tup_db->datpath))-VARHDRSZ) = '\0';
+
+ goto done;
+ }
+ }
+ }
+
+done:
+ close(dbfd);
+ pfree(pg);
+} /* GetRawDatabaseInfo() */
projects / postgresql.git / commitdiff