|
| 1 | +/*------------------------------------------------------------------------- |
| 2 | + * |
| 3 | + * database.c-- |
| 4 | + * miscellanious initialization support stuff |
| 5 | + * |
| 6 | + * Copyright (c) 1994, Regents of the University of California |
| 7 | + * |
| 8 | + * |
| 9 | + * IDENTIFICATION |
| 10 | + * $Header: /cvsroot/pgsql/src/backend/utils/misc/Attic/database.c,v 1.1 1997/11/07 07:05:46 thomas Exp $ |
| 11 | + * |
| 12 | + *------------------------------------------------------------------------- |
| 13 | + */ |
| 14 | +#include<string.h> |
| 15 | +#include<stdlib.h> |
| 16 | +#include<stdio.h> |
| 17 | +#include<unistd.h> |
| 18 | +#include<fcntl.h> |
| 19 | + |
| 20 | +#include"postgres.h" |
| 21 | +#include"miscadmin.h" |
| 22 | + |
| 23 | +#include"utils/elog.h" |
| 24 | +#include"utils/builtins.h" |
| 25 | +#include"utils/syscache.h" |
| 26 | + |
| 27 | +#include"access/heapam.h" |
| 28 | +#include"storage/bufmgr.h" |
| 29 | +#include"catalog/catname.h" |
| 30 | +#include"catalog/pg_proc.h" |
| 31 | +#include"catalog/pg_database.h" |
| 32 | + |
| 33 | +#include"access/xact.h" |
| 34 | +#include"storage/bufpage.h" |
| 35 | + |
| 36 | +/* GetDatabaseInfo() |
| 37 | + * Pull database information from pg_database. |
| 38 | + */ |
| 39 | +int |
| 40 | +GetDatabaseInfo(char*name,Oid*owner,char*path) |
| 41 | +{ |
| 42 | +Oiddbowner, |
| 43 | +dbid; |
| 44 | +chardbpath[MAXPGPATH+1]; |
| 45 | +text*dbtext; |
| 46 | + |
| 47 | +Relationdbrel; |
| 48 | +HeapTupledbtup; |
| 49 | +HeapTupletup; |
| 50 | +Bufferbuf; |
| 51 | +HeapScanDescscan; |
| 52 | +ScanKeyDatascanKey; |
| 53 | + |
| 54 | +dbrel=heap_openr(DatabaseRelationName); |
| 55 | +if (!RelationIsValid(dbrel)) |
| 56 | +elog(FATAL,"GetDatabaseInfo: cannot open relation \"%-.*s\"", |
| 57 | +DatabaseRelationName); |
| 58 | + |
| 59 | +ScanKeyEntryInitialize(&scanKey,0,Anum_pg_database_datname, |
| 60 | +NameEqualRegProcedure,NameGetDatum(name)); |
| 61 | + |
| 62 | +scan=heap_beginscan(dbrel,0,NowTimeQual,1,&scanKey); |
| 63 | +if (!HeapScanIsValid(scan)) |
| 64 | +elog(WARN,"GetDatabaseInfo: cannot begin scan of %s",DatabaseRelationName); |
| 65 | + |
| 66 | +/* |
| 67 | + * Since we're going to close the relation, copy the tuple. |
| 68 | + */ |
| 69 | +tup=heap_getnext(scan,0,&buf); |
| 70 | + |
| 71 | +if (HeapTupleIsValid(tup)) |
| 72 | +{ |
| 73 | +dbtup=heap_copytuple(tup); |
| 74 | +ReleaseBuffer(buf); |
| 75 | +} |
| 76 | +else |
| 77 | +dbtup=tup; |
| 78 | + |
| 79 | +heap_endscan(scan); |
| 80 | + |
| 81 | +if (!HeapTupleIsValid(dbtup)) |
| 82 | +{ |
| 83 | +elog(NOTICE,"GetDatabaseInfo: %s entry not found %s", |
| 84 | +DatabaseRelationName,name); |
| 85 | +return TRUE; |
| 86 | +} |
| 87 | + |
| 88 | +dbowner= (Oid)heap_getattr(dbtup,InvalidBuffer, |
| 89 | +Anum_pg_database_datdba, |
| 90 | +RelationGetTupleDescriptor(dbrel), |
| 91 | +(char*)NULL); |
| 92 | +dbid=dbtup->t_oid; |
| 93 | + |
| 94 | +dbtext= (text*)heap_getattr(dbtup,InvalidBuffer, |
| 95 | +Anum_pg_database_datpath, |
| 96 | +RelationGetTupleDescriptor(dbrel), |
| 97 | +(char*)NULL); |
| 98 | + |
| 99 | +memcpy(dbpath,VARDATA(dbtext), (VARSIZE(dbtext)-VARHDRSZ)); |
| 100 | +*(dbpath+(VARSIZE(dbtext)-VARHDRSZ))='\0'; |
| 101 | + |
| 102 | +heap_close(dbrel); |
| 103 | + |
| 104 | +owner=palloc(sizeof(Oid)); |
| 105 | +*owner=dbowner; |
| 106 | +path=palloc(strlen(dbpath)+1); |
| 107 | +strcpy(path,dbpath); |
| 108 | + |
| 109 | +return FALSE; |
| 110 | +}/* GetDatabaseInfo() */ |
| 111 | + |
| 112 | +char* |
| 113 | +ExpandDatabasePath(char*dbpath) |
| 114 | +{ |
| 115 | +char*path; |
| 116 | +char*cp; |
| 117 | +charbuf[MAXPGPATH+1]; |
| 118 | + |
| 119 | +/* leading path delimiter? then already absolute path */ |
| 120 | +if (*dbpath==SEP_CHAR) |
| 121 | +{ |
| 122 | +cp=strrchr(dbpath,SEP_CHAR); |
| 123 | +strncpy(buf,dbpath,(cp-dbpath)); |
| 124 | +sprintf(&buf[cp-dbpath],"%cbase%c%s",SEP_CHAR,SEP_CHAR, (cp+1)); |
| 125 | +} |
| 126 | +/* path delimiter somewhere? then has leading environment variable */ |
| 127 | +elseif (strchr(dbpath,SEP_CHAR)!=NULL) |
| 128 | +{ |
| 129 | +cp=strchr(dbpath,SEP_CHAR); |
| 130 | +strncpy(buf,dbpath,(cp-dbpath)); |
| 131 | +buf[cp-dbpath]='\0'; |
| 132 | +path=getenv(buf); |
| 133 | +sprintf(buf,"%s%cbase%c%s",path,SEP_CHAR,SEP_CHAR, (cp+1)); |
| 134 | +} |
| 135 | +/* no path delimiter? then add the default path prefixes */ |
| 136 | +else |
| 137 | +{ |
| 138 | +sprintf(buf,"%s%cbase%c%s",DataDir,SEP_CHAR,SEP_CHAR,dbpath); |
| 139 | +} |
| 140 | + |
| 141 | +path=palloc(strlen(buf)+1); |
| 142 | +strcpy(path,buf); |
| 143 | + |
| 144 | +returnpath; |
| 145 | +}/* ExpandDatabasePath() */ |
| 146 | + |
| 147 | + |
| 148 | +/* -------------------------------- |
| 149 | + *GetRawDatabaseInfo() -- Find the OID and path of the database. |
| 150 | + * |
| 151 | + *The database's oid forms half of the unique key for the system |
| 152 | + *caches and lock tables. We therefore want it initialized before |
| 153 | + *we open any relations, since opening relations puts things in the |
| 154 | + *cache.To get around this problem, this code opens and scans the |
| 155 | + *pg_database relation by hand. |
| 156 | + * |
| 157 | + *This algorithm relies on the fact that first attribute in the |
| 158 | + *pg_database relation schema is the database name. It also knows |
| 159 | + *about the internal format of tuples on disk and the length of |
| 160 | + *the datname attribute.It knows the location of the pg_database |
| 161 | + *file. |
| 162 | + *Actually, the code looks as though it is using the pg_database |
| 163 | + *tuple definition to locate the database name, so the above statement |
| 164 | + *seems to be no longer correct. - thomas 1997-11-01 |
| 165 | + * |
| 166 | + *This code is called from InitPostgres(), before we chdir() to the |
| 167 | + *local database directory and before we open any relations. |
| 168 | + *Used to be called after the chdir(), but we now want to confirm |
| 169 | + *the location of the target database using pg_database info. |
| 170 | + *- thomas 1997-11-01 |
| 171 | + * -------------------------------- |
| 172 | + */ |
| 173 | +void |
| 174 | +GetRawDatabaseInfo(char*name,Oid*owner,Oid*db_id,char*path) |
| 175 | +{ |
| 176 | +intdbfd; |
| 177 | +intfileflags; |
| 178 | +intnbytes; |
| 179 | +intmax, |
| 180 | +i; |
| 181 | +HeapTupletup; |
| 182 | +Pagepg; |
| 183 | +PageHeaderph; |
| 184 | +char*dbfname; |
| 185 | +Form_pg_databasetup_db; |
| 186 | + |
| 187 | +dbfname= (char*)palloc(strlen(DataDir)+strlen("pg_database")+2); |
| 188 | +sprintf(dbfname,"%s%cpg_database",DataDir,SEP_CHAR); |
| 189 | +fileflags=O_RDONLY; |
| 190 | + |
| 191 | +if ((dbfd=open(dbfname,O_RDONLY,0))<0) |
| 192 | +elog(FATAL,"Cannot open %s",dbfname); |
| 193 | + |
| 194 | +pfree(dbfname); |
| 195 | + |
| 196 | +/* ---------------- |
| 197 | + *read and examine every page in pg_database |
| 198 | + * |
| 199 | + *Raw I/O! Read those tuples the hard way! Yow! |
| 200 | + * |
| 201 | + *Why don't we use the access methods or move this code |
| 202 | + *someplace else? This is really pg_database schema dependent |
| 203 | + *code. Perhaps it should go in lib/catalog/pg_database? |
| 204 | + *-cim 10/3/90 |
| 205 | + * |
| 206 | + *mao replies 4 apr 91: yeah, maybe this should be moved to |
| 207 | + *lib/catalog. however, we CANNOT use the access methods since |
| 208 | + *those use the buffer cache, which uses the relation cache, which |
| 209 | + *requires that the dbid be set, which is what we're trying to do |
| 210 | + *here. |
| 211 | + * ---------------- |
| 212 | + */ |
| 213 | +pg= (Page)palloc(BLCKSZ); |
| 214 | +ph= (PageHeader)pg; |
| 215 | + |
| 216 | +while ((nbytes=read(dbfd,pg,BLCKSZ))==BLCKSZ) |
| 217 | +{ |
| 218 | +max=PageGetMaxOffsetNumber(pg); |
| 219 | + |
| 220 | +/* look at each tuple on the page */ |
| 221 | +for (i=0;i <=max;i++) |
| 222 | +{ |
| 223 | +intoffset; |
| 224 | + |
| 225 | +/* if it's a freed tuple, ignore it */ |
| 226 | +if (!(ph->pd_linp[i].lp_flags&LP_USED)) |
| 227 | +continue; |
| 228 | + |
| 229 | +/* get a pointer to the tuple itself */ |
| 230 | +offset= (int)ph->pd_linp[i].lp_off; |
| 231 | +tup= (HeapTuple) (((char*)pg)+offset); |
| 232 | + |
| 233 | +/* |
| 234 | + * if the tuple has been deleted (the database was destroyed), |
| 235 | + * skip this tuple. XXX warning, will robinson: violation of |
| 236 | + * transaction semantics happens right here. we should check |
| 237 | + * to be sure that the xact that deleted this tuple actually |
| 238 | + * committed. only way to do this at init time is to paw over |
| 239 | + * the log relation by hand, too. let's be optimistic. |
| 240 | + * |
| 241 | + * XXX This is an evil type cast. tup->t_xmax is char[5] while |
| 242 | + * TransactionId is struct * { char data[5] }.It works but |
| 243 | + * if data is ever moved and no longer the first field this |
| 244 | + * will be broken!! -mer 11 Nov 1991. |
| 245 | + */ |
| 246 | +if (TransactionIdIsValid((TransactionId)tup->t_xmax)) |
| 247 | +continue; |
| 248 | + |
| 249 | +/* |
| 250 | + * Okay, see if this is the one we want. XXX 1 july 91: mao |
| 251 | + * and mer discover that tuples now squash t_bits.Why is |
| 252 | + * this? |
| 253 | + * |
| 254 | + * 24 july 92:mer realizes that the t_bits field is only used |
| 255 | + * in the event of null values. If no fields are null we |
| 256 | + * reduce the header size by doing the squash.t_hoff tells |
| 257 | + * you exactly how big the header actually is. use the PC |
| 258 | + * means of getting at sys cat attrs. |
| 259 | + */ |
| 260 | +tup_db= (Form_pg_database)GETSTRUCT(tup); |
| 261 | + |
| 262 | +if (strncmp(name, |
| 263 | +&(tup_db->datname.data[0]), |
| 264 | +16)==0) |
| 265 | +{ |
| 266 | +*db_id=tup->t_oid; |
| 267 | +strncpy(path,VARDATA(&(tup_db->datpath)), |
| 268 | + (VARSIZE(&(tup_db->datpath))-VARHDRSZ)); |
| 269 | +*(path+VARSIZE(&(tup_db->datpath))-VARHDRSZ)='\0'; |
| 270 | + |
| 271 | +gotodone; |
| 272 | +} |
| 273 | +} |
| 274 | +} |
| 275 | + |
| 276 | +done: |
| 277 | +close(dbfd); |
| 278 | +pfree(pg); |
| 279 | +}/* GetRawDatabaseInfo() */ |
