1: # include   <ingres.h>
   2: # include   <aux.h>
   3: # include   <tree.h>
   4: # include   <symbol.h>
   5: # include   "globs.h"
   6: # include   <sccs.h>
   7: 
   8: SCCSID(@(#)openrs.c	8.2	1/15/85)
   9: 
  10: 
  11: 
  12: 
  13: /* Defined constants for dtmode field above */
  14: # define    DTALLOC     0   /* descriptor allocated */
  15: # define    DTREL       1   /* has been openr'd -1 */
  16: # define    DTATTS      2   /* has rel+atts but not opened */
  17: # define    DTREAD      3   /* currently open for reading */
  18: # define    DTWRITE     4   /* currently open for writing */
  19: 
  20: 
  21: 
  22: /* Allocation of descriptors */
  23: 
  24: /* Globals which count #files open and maximum # of files which can be open */
  25: 
  26: 
  27: /*
  28: ** OPENRS -- routines associated with maintaining the range table for decomp
  29: **
  30: **	openrs(root) -- fill range table info about each relation.
  31: **
  32: **	closers() -- close all variables in range table.
  33: **
  34: **	openr1(varno) -- fill range table for a particular relation.
  35: **
  36: **	closer1(varno) -- close a particular relation.
  37: **
  38: **	readopen(varno) -- open a variable for reading. returns descriptor.
  39: **
  40: **	writeopen(varno) -- open a variable for writing. returns descriptor.
  41: **
  42: **	initdesc()	-- initialize the descriptor cache.
  43: **
  44: **	reldescrip(varno) -- returns descriptor for var (has rel/atts
  45: **		but might not be open).
  46: **
  47: **	desc_get(relnum, flag) -- finds a desc_tab & alloctes it for relnum.
  48: **
  49: **	desc_lru()  -- returns least recently used desc_tab.
  50: **
  51: **	desc_top(desc_tab) -- makes desc_tab most recently used.
  52: **
  53: **	desc_last(desc_tab) -- makes desc_tab the least recently used.
  54: **
  55: **	Trace Flags:
  56: **		62
  57: */
  58: /*
  59: ** Initdesc -- initialize descriptors for range table
  60: */
  61: 
  62: initdesc(mode)
  63: int mode;
  64: {
  65:     register struct desc_tab    *dt;
  66:     register int            i;
  67:     extern int          Equel;
  68: 
  69: 
  70:     for (dt = De.de_desc, i = 0; dt <= &De.de_desc[MAXRELN - 1]; dt++, i++)
  71:     {
  72:         dt->dtmode = DTALLOC;
  73:         dt->relnum = -2;    /* unused relnum value */
  74:         dt->dtpos = i;      /* lru order */
  75:     }
  76: 
  77:     /*
  78: 	** Determine number of available file descriptors.
  79: 	**	av_files gives number of files that are def. open
  80: 	**	for users.  if we will need to open a batch file,
  81: 	**	get rid of that also.
  82: 	*/
  83: 
  84:     De.de_dfiles = av_files();
  85:     if (mode != mdRETR)
  86:         De.de_dfiles--;
  87:     De.de_dopnfiles = 0;
  88: }
  89: /*
  90: **	Openrs -- open source relations for query. Fill values
  91: **		in range table.
  92: */
  93: 
  94: openrs(root)
  95: QTREE   *root;
  96: {
  97:     register QTREE  *r;
  98:     register int    map, i;
  99:     DESC        *openr1();
 100: 
 101:     r = root;
 102:     map = r->sym.value.sym_root.lvarm | r->sym.value.sym_root.rvarm;
 103: 
 104: #	ifdef xDTR1
 105:     if (tTf(62, 0))
 106:         printf("OPENRS-root:%x,map:%o\n", r, map);
 107: #	endif
 108: 
 109:     for (i = 0; i < MAXRANGE; i++)
 110:         if (map & (01 << i))
 111:             openr1(i);
 112: 
 113: }
 114: /*
 115: **	Close all open relations.
 116: **	If any relations were created but never
 117: **	opened, destroy them. The only
 118: **	situation under which that can occur
 119: **	is when a rub-out occurs at an
 120: **	in opportune moment or when an error
 121: **	occurs in ovqp.
 122: */
 123: 
 124: closers()
 125: {
 126:     register int            i;
 127:     register struct desc_tab    *dt;
 128:     bool                dstr_flag;
 129: 
 130: 
 131:     for (dt = De.de_desc; dt <= &De.de_desc[MAXRELN - 1]; dt++)
 132:         desc_close(dt);
 133: 
 134:     /* destroy any temps */
 135:     initp();    /* init parameters vector for destroys */
 136:     dstr_flag = FALSE;
 137:     while (i = rnum_last())
 138:     {
 139:         dstr_flag |= dstr_mark(i); /* indicate that there are relations to be destroyed */
 140:     }
 141: 
 142:     if (dstr_flag)
 143:         call_dbu(mdDESTROY, TRUE);
 144:     else
 145:         resetp();
 146: }
 147: /*
 148: **	Openr1 -- open relation to get relation relation tuple
 149: **
 150: **	This will not open the relation for reading -- only
 151: **	for getting the first part of the descriptor filled
 152: */
 153: 
 154: DESC *
 155: openr1(var)
 156: int var;
 157: {
 158:     register struct desc_tab    *dt;
 159:     register struct rang_tab    *rp;
 160:     register DESC   *d;
 161:     int             i;
 162:     struct desc_tab         *desc_get();
 163:     extern char         *rnum_convert();
 164: 
 165:     rp = &De.de_rangev[var];
 166: 
 167: #	ifdef xDTR1
 168:     if (tTf(62, 2))
 169:         printf("openr1: var %d (%s)\t", var, rnum_convert(rp->relnum));
 170: #	endif
 171: 
 172:     dt = desc_get(rp->relnum, TRUE);
 173: 
 174:     if (dt->dtmode == DTALLOC)
 175:     {
 176:         if (i = openr(&dt->desc, OR_RELTID, rnum_convert(rp->relnum)))
 177:             syserr("openr1 open %d %s", i, rnum_convert(rp->relnum));
 178:         dt->dtmode = DTREL;
 179:     }
 180: 
 181: #	ifdef xDTR1
 182:     if (tTf(62, 2))
 183:         printf("tups=%ld\n", dt->desc.reldum.reltups);
 184: #	endif
 185: 
 186:     d = &dt->desc;
 187: 
 188:     rp->rtspec = d->reldum.relspec;
 189:     rp->rtstat = d->reldum.relstat;
 190:     rp->rtwid = d->reldum.relwid;
 191:     rp->rtcnt = d->reldum.reltups;
 192: 
 193:     return (d);
 194: }
 195: /*
 196: **  CLOSER1
 197: */
 198: 
 199: closer1(var)
 200: int var;
 201: {
 202:     register struct desc_tab    *dt;
 203:     register struct rang_tab    *rp;
 204:     register int            i;
 205:     struct desc_tab         *desc_get();
 206:     struct desc_tab         *desc_last();
 207: 
 208:     i = var;
 209:     rp = &De.de_rangev[i];
 210: 
 211: #	ifdef xDTR1
 212:     if (tTf(62, 4))
 213:         printf("closer1:var %d (%s)\n", i, rnum_convert(rp->relnum));
 214: #	endif
 215:     if (dt = desc_get(rp->relnum, FALSE))
 216:     {
 217: 
 218:         /* currently a descriptor for rel */
 219:         desc_close(dt);
 220: 
 221:         dt->relnum = -2;
 222:         desc_last(dt);
 223: 
 224:     }
 225: }
 226: /*
 227: **  READOPEN
 228: */
 229: 
 230: DESC *
 231: readopen(var)
 232: int var;
 233: {
 234:     register struct desc_tab    *dt;
 235:     struct desc_tab         *desc_get();
 236: 
 237:     /* get descv for the relation */
 238:     dt = desc_get(De.de_rangev[var].relnum, TRUE);
 239: 
 240:     if (!(dt->dtmode == DTREAD || dt->dtmode == DTWRITE))
 241:     {
 242:         /* not open for reading or writing */
 243:         openup(dt, var, OR_READ);   /* open for reading */
 244:     }
 245: 
 246:     return (&dt->desc);
 247: }
 248: /*
 249: **  WRITEOPEN
 250: */
 251: 
 252: DESC *
 253: writeopen(var)
 254: int var;
 255: {
 256:     register struct desc_tab    *dt;
 257: 
 258:     /* get descv for the relation */
 259:     dt = desc_get(De.de_rangev[var].relnum, TRUE);
 260: 
 261:     if (dt->dtmode != DTWRITE)
 262:     {
 263:         /* not open for writing */
 264:         openup(dt, var, OR_WRITE);  /* open for reading */
 265:     }
 266: 
 267:     return (&dt->desc);
 268: }
 269: /*
 270: **  SPECOPEN -- open for writing not associated with any variable
 271: */
 272: 
 273: DESC *
 274: specopen(relnum)
 275: int relnum;
 276: {
 277:     register struct desc_tab    *dt;
 278:     struct desc_tab         *desc_get();
 279: 
 280:     dt = desc_get(relnum, TRUE);
 281: 
 282:     if (dt->dtmode != DTWRITE)
 283:         openup(dt, -1, OR_WRITE);
 284: 
 285:     return (&dt->desc);
 286: }
 287: /*
 288: **  SPECCLOSE
 289: */
 290: 
 291: specclose(relnum)
 292: int relnum;
 293: {
 294:     register struct desc_tab    *dt;
 295:     struct desc_tab         *desc_get();
 296:     struct desc_tab         *desc_last();
 297: 
 298:     if (dt = desc_get(relnum, FALSE))
 299:     {
 300:         desc_close(dt);
 301:         desc_last(dt);
 302:         dt->relnum = -2;
 303:     }
 304: }
 305: /*
 306: **	Openup -- make sure that the given descriptor is open
 307: **		suitably for reading or writing.
 308: */
 309: 
 310: openup(dt1, varno, mode)
 311: struct desc_tab *dt1;
 312: int     varno;
 313: int     mode;
 314: {
 315:     register struct desc_tab    *dt;
 316:     register int            md, openmd;
 317:     int             i;
 318:     extern char         *rnum_convert();
 319:     char                rnam_tmp[MAXNAME+3];
 320: 
 321:     /* quick check to handle typical case of rel being already open */
 322:     md = mode;
 323:     dt = dt1;
 324:     if ((md != OR_WRITE && dt->dtmode == DTREAD) || dt->dtmode == DTWRITE)
 325:         return;
 326: 
 327:     /* relation not opened correctly */
 328:     switch (dt->dtmode)
 329:     {
 330: 
 331:       case DTALLOC:
 332:         /*
 333: 		** Descriptor allocated but nothing else. If this
 334: 		** is for a variable then use openr1 to get range table
 335: 		** info. Else open directly.
 336: 		*/
 337:         if (varno < 0)
 338:         {
 339:             /* open unassociated with a range table variable */
 340:             openmd = md ? OR_WRITE : OR_READ;
 341:             bmove(rnum_convert(dt->relnum), dt->desc.reldum.relid, MAXNAME);
 342:             break;
 343:         }
 344: 
 345:         /* open for range table variable */
 346:         openr1(varno);
 347: 
 348:         /* now fall through to DTREL case */
 349: 
 350:       case DTREL:
 351:         /* relation relation tuple present but nothing else */
 352:         openmd = md ? OR_AWRITE : OR_AREAD; /* open AREAD for read, AWRITE for write */
 353:         break;
 354: 
 355:       case DTATTS:
 356:         /* relation & attributes filled but relation closed */
 357:         openmd = md ? OR_REWRITE : OR_REREAD;
 358:         break;
 359:       case DTREAD:
 360:         /* relation open for reading but we need to write */
 361:         desc_close(dt);
 362: 
 363:         openmd = OR_REWRITE;
 364:         break;
 365: 
 366:       default:
 367:         syserr("openup:bad md %d", dt->dtmode);
 368:     }
 369: 
 370:     /* close a previous file if necessary */
 371:     if (De.de_dopnfiles == De.de_dfiles)
 372:         desc_victum();  /* close oldest file */
 373: 
 374:     /* now open relation */
 375:     bmove(dt->desc.reldum.relid, rnam_tmp, MAXNAME + 3);
 376:     if (i = openr(&dt->desc, openmd, rnam_tmp))
 377:         syserr("openup:openr %d,%d,%.12s,%s", i, openmd, rnam_tmp, rnum_convert(dt->relnum));
 378:     De.de_dopnfiles++;
 379: 
 380:     /* update mode of descriptor */
 381:     dt->dtmode = md ? DTWRITE : DTREAD;
 382: }
 383: /*
 384: **  DESC_GET
 385: */
 386: 
 387: struct desc_tab *
 388: desc_get(relnum, flag)
 389: int relnum;
 390: bool    flag;
 391: {
 392:     register struct desc_tab    *dt, *ret;
 393:     struct desc_tab         *desc_lru();
 394: 
 395:     ret = NULL;
 396: 
 397:     /* search for one currently allocated */
 398:     for (dt = &De.de_desc[0]; dt <= &De.de_desc[MAXRELN-1]; dt++)
 399:     {
 400:         if (dt->relnum == relnum)
 401:         {
 402:             ret = dt;
 403: #			ifdef xDTR1
 404:             if (tTf(62, 3))
 405:                 printf("found desc for %d\n", relnum);
 406: #			endif
 407:             break;
 408:         }
 409:     }
 410: 
 411:     if (ret == NULL && flag)
 412:     {
 413:         /* get a victim and deallocate desc */
 414:         ret = desc_lru();
 415: 
 416:         /* deallocate */
 417: #		ifdef xDTR1
 418:         if (tTf(62, 5))
 419:             printf("trading %d for %d\n", ret->relnum, relnum);
 420: #		endif
 421:         desc_close(ret);
 422: 
 423:         /* allocate */
 424:         ret->relnum = relnum;
 425:         ret->dtmode = DTALLOC;
 426:     }
 427: 
 428:     if (ret != NULL)
 429:         desc_top(ret);
 430: 
 431:     return (ret);
 432: }
 433: /*
 434: **	For text space reasons only, the close relation routine varies
 435: **	between decomp and decomp70. In decomp, the relation is opened
 436: **	only for reading and never for writing thus inpcloser() can be
 437: **	called. For decomp70 closer() must be called. If there were no
 438: **	text space shortage, then closer() could always be called.
 439: **	The routine init_decomp() assigned the value to Des_closefunc.
 440: */
 441: 
 442: extern int  (*Des_closefunc)(); /* either &inpcloser or &closer */
 443: 
 444: desc_close(dt1)
 445: struct desc_tab *dt1;
 446: {
 447:     register struct desc_tab    *dt;
 448:     register int            i;
 449: 
 450:     dt = dt1;
 451: 
 452:     if (dt->dtmode == DTREAD || dt->dtmode == DTWRITE)
 453:     {
 454:         if (i = (*Des_closefunc)(&dt->desc))
 455:             syserr("desc_close:closer %d,%.12s", i, dt->desc.reldum.relid);
 456:         De.de_dopnfiles--;
 457:         dt->dtmode = DTATTS;
 458:     }
 459: }
 460: /*
 461: ** Desc_top -- make the desc_tab entry "dtx" the most recently used.
 462: */
 463: 
 464: desc_top(dt1)
 465: struct desc_tab *dt1;
 466: {
 467:     register struct desc_tab    *dt, *dx;
 468:     register int            oldpos;
 469: 
 470:     dt = dt1;
 471: 
 472:     if ((oldpos = dt->dtpos) != 0)
 473:     {
 474:         /* descriptor isn't currently top */
 475:         for (dx = De.de_desc; dx <= &De.de_desc[MAXRELN-1]; dx++)
 476:             if (dx->dtpos < oldpos)
 477:                 dx->dtpos++;
 478: 
 479:         /* make descriptor first */
 480:         dt->dtpos = 0;
 481:     }
 482: }
 483: /*
 484: ** Desc_last -- make the desc_tab entry "dt" the least recently used.
 485: */
 486: 
 487: struct desc_tab *
 488: desc_last(dt)
 489: register struct desc_tab    *dt;
 490: {
 491:     register int            oldpos;
 492:     register struct desc_tab    *dx;
 493: 
 494:     oldpos = dt->dtpos;
 495:     for (dx = De.de_desc; dx <= &De.de_desc[MAXRELN-1]; dx++)
 496:         if (dx->dtpos > oldpos)
 497:             dx->dtpos--;
 498: 
 499:     /* make descriptor last */
 500:     dt->dtpos = MAXRELN - 1;
 501: }
 502: /*
 503: ** Desc_lru -- return least recently used descriptor
 504: */
 505: 
 506: struct desc_tab *
 507: desc_lru()
 508: {
 509:     register struct desc_tab    *dx;
 510: 
 511:     for (dx = De.de_desc; dx <= &De.de_desc[MAXRELN-1]; dx++)
 512:     {
 513:         if (dx->dtpos == MAXRELN - 1)
 514:             return (dx);
 515:     }
 516:     syserr("desc_lru:no lru");
 517:     /*NOTREACHED*/
 518: }
 519: 
 520: 
 521: desc_victum()
 522: {
 523:     register struct desc_tab    *dt, *old;
 524: 
 525:     old = NULL;
 526:     for (dt = &De.de_desc[0]; dt <= &De.de_desc[MAXRELN-1]; dt++)
 527:     {
 528:         if (dt->dtmode == DTWRITE || dt->dtmode == DTREAD)
 529:         {
 530:             if (old == NULL || dt->dtpos > old->dtpos)
 531:                 old = dt;
 532:         }
 533:     }
 534: 
 535:     if (old == NULL)
 536:         syserr("desc_victum:no victum %d,%d", De.de_dopnfiles, De.de_dfiles);
 537:     desc_close(old);
 538: }

Defined functions

closers defined in line 124; used 1 times
desc_close defined in line 444; used 6 times
desc_get defined in line 387; used 11 times
desc_last defined in line 487; used 4 times
desc_lru defined in line 506; used 2 times
desc_top defined in line 464; used 1 times
desc_victum defined in line 521; used 1 times
initdesc defined in line 8; used 1 times
openrs defined in line 94; used 1 times
openup defined in line 310; used 3 times
specopen defined in line 273; used 2 times
writeopen defined in line 252; never used

Defined macros

DTALLOC defined in line 14; used 3 times
DTATTS defined in line 16; used 1 times
DTREAD defined in line 17; used 5 times
DTREL defined in line 15; used 1 times
DTWRITE defined in line 18; used 7 times
Last modified: 1986-04-17
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