1: # include   "../ingres.h"
   2: # include   "../catalog.h"
   3: # include   "../tree.h"
   4: # include   "../symbol.h"
   5: # include   "../pipes.h"
   6: # include   "qrymod.h"
   7: 
   8: /*
   9: **  READTREE.C -- query tree input procedures
  10: **
  11: **	This file contains routines to read trees from pipes and
  12: **	catalogs.
  13: **
  14: **	Defines:
  15: **		readqry
  16: **		readsym
  17: **		readtree
  18: **		pipetrrd
  19: **		relntrrd
  20: **		gettree
  21: **		Qmode
  22: **		Resultvar
  23: **
  24: **	Requires:
  25: **		prtree.c
  26: **
  27: **	Required By:
  28: **		main.c
  29: **		view.c
  30: **		protect.c
  31: **		integ.c
  32: **
  33: **	Trace Flags:
  34: **		70
  35: **
  36: **	History:
  37: **		2/14/79 -- version 6.2/0 release.
  38: */
  39: 
  40: 
  41: extern struct pipfrmt   Pipe, Outpipe;
  42: 
  43: int Qmode;      /* Query mode */
  44: int Resultvar;  /* Result variable number */
  45: /*
  46: ** READQRY
  47: **
  48: ** 	Reads in query symbols from input pipe into core
  49: **	locations and sets up information needed for later
  50: **	processing.
  51: **
  52: **	Returns ptr to root of querytree
  53: **
  54: **	Locbuf is a 'struct srcid' since that is the largest node of
  55: **	a QMODE, SOURCEID, or RESULTVAR node.
  56: */
  57: 
  58: QTREE *
  59: readqry(rdfn, initialize)
  60: int (*rdfn)();  /* tree read function */
  61: int initialize; /* if set, initialize Qbuf */
  62: {
  63:     register struct symbol  *s;
  64:     struct srcid        locbuf;
  65:     register QTREE      *rtval;
  66:     register char       *p;
  67:     extern          xerror();
  68:     char            *readtree();
  69:     QTREE           *trbuild();
  70: 
  71: #	ifdef xQTR1
  72:     tTfp(70, 0, "READQRY:\n");
  73: #	endif
  74: 
  75:     if (initialize)
  76:     {
  77:         /* initialize for new query block */
  78:         initbuf(Qbuf, QBUFSIZ, QBUFFULL, &xerror);
  79:         clrrange(TRUE);
  80:         Resultvar = -1;
  81:         Qmode = -1;
  82:     }
  83:     else
  84:         clrrange(FALSE);
  85: 
  86:     s = (struct symbol *) &locbuf;
  87: 
  88:     /* read symbols from input */
  89:     for (;;)
  90:     {
  91:         readsym(s, rdfn);
  92: #		ifdef xQTR1
  93:         if (tTf(70, 1))
  94:         {
  95:             printf("%d, %d, %d/", s->type, s->len, s->value[0] & 0377);
  96:             if (s->type == SOURCEID)
  97:                 printf("%.12s", ((struct srcid *)s)->srcname);
  98:             printf("\n");
  99:         }
 100: #		endif
 101:         switch (s->type)
 102:         {
 103:           case QMODE:
 104:             if (Qmode != -1)
 105:                 syserr("readqry: two Qmodes");
 106:             Qmode = s->value[0];
 107:             break;
 108: 
 109:           case RESULTVAR:
 110:             if (Resultvar != -1)
 111:                 syserr("readqry: two Resultvars");
 112:             Resultvar = s->value[0];
 113:             break;
 114: 
 115:           case SOURCEID:
 116:             declare(((struct srcid *)s)->srcvar,
 117:                 ((struct srcid *)s)->srcname,
 118:                 ((struct srcid *)s)->srcown,
 119:                 ((struct srcid *)s)->srcstat);
 120:             break;
 121: 
 122:           case TREE:    /* beginning of tree, no more other stuff */
 123:             p = readtree(s, rdfn);
 124:             rtval = trbuild(p);
 125:             if (rtval == NULL)
 126:                 ferror(STACKFULL, -1, -1, 0);
 127:             return (rtval);
 128: 
 129:           default:
 130:             syserr("readq: bad symbol %d", s->type);
 131:         }
 132:     }
 133: }
 134: /*
 135: ** readsym
 136: **	reads in one symbol from pipe into symbol struct.
 137: */
 138: readsym(dest, rdfn)
 139: char    *dest;      /* if non-zero, pts to allocated space */
 140: int (*rdfn)();  /* tree read function */
 141: {
 142:     register int        len, t;
 143:     register struct symbol  *p;
 144:     char            *need();
 145: 
 146:     /* check if enough space for type and len of sym */
 147:     p = (struct symbol *) ((dest != NULL) ? dest : need(Qbuf, 2));
 148:     if ((*rdfn)(p, 2) < 2)
 149:         goto err3;
 150:     len = p->len & I1MASK;
 151:     t = p->type;
 152:     if (len)
 153:     {
 154:         if (dest == NULL)
 155:         {
 156:             /* this will be contiguous with above need call */
 157:             need(Qbuf, len);
 158:         }
 159:         if ((*rdfn)(p->value, len) < len)
 160:             goto err3;
 161:     }
 162: 
 163:     return;
 164: 
 165: err3:
 166:     syserr("readsym: read");
 167: }
 168: /*
 169: ** readtree
 170: **
 171: ** 	reads in tree symbols into a buffer up to a root (end) symbol
 172: **
 173: */
 174: 
 175: char *readtree(tresym, rdfn)
 176: struct symbol   *tresym;
 177: int     (*rdfn)();
 178: {
 179:     register QTREE  *nod;
 180:     register char   *rtval;
 181:     char        *need();
 182: 
 183:     rtval = need(Qbuf, 6);
 184:     bmove(tresym, &(((struct querytree *)rtval)->sym), 2);  /* insert type and len of TREE node */
 185:     for(;;)
 186:     {
 187:         /* space for left & right pointers */
 188:         nod = (QTREE *) need(Qbuf, 4);
 189:         readsym(NULL, rdfn);
 190: #		ifdef xQTR1
 191:         if (tTf(70, 2))
 192:             nodepr(nod, TRUE);
 193: #		endif
 194:         if (nod->sym.type == ROOT)
 195:             return (rtval);
 196:     }
 197: }
 198: /*
 199: **  PIPETRRD -- read tree from R_up pipe
 200: **
 201: **	This routine looks like a rdpipe with only the last two
 202: **	parameters.
 203: **
 204: **	Parameters:
 205: **		ptr -- pointer to data area
 206: **		cnt -- byte count
 207: **
 208: **	Returns:
 209: **		actual number of bytes read
 210: **
 211: **	Side Effects:
 212: **		as with rdpipe()
 213: **
 214: **	Requires:
 215: **		rdpipe()
 216: **
 217: **	Called By:
 218: **		readsym (indirectly via main)
 219: **
 220: **	Diagnostics:
 221: **		none
 222: **
 223: **	Syserrs:
 224: **		none
 225: */
 226: 
 227: pipetrrd(ptr, cnt)
 228: char    *ptr;
 229: int cnt;
 230: {
 231:     return (rdpipe(P_NORM, &Pipe, R_up, ptr, cnt));
 232: }
 233: /*
 234: **  RELNTRRD -- read tree from 'tree' relation
 235: **
 236: **	This looks exactly like the 'pipetrrd' call, except that info
 237: **	comes from the 'tree' catalog instead of from the pipe.  It
 238: **	must be initialized by calling it with a NULL pointer and
 239: **	the segment name wanted as 'treeid'.
 240: **
 241: **	Parameters:
 242: **		ptr -- NULL -- "initialize".
 243: **			else -- pointer to read area.
 244: **		cnt -- count of number of bytes to read.
 245: **		treeid -- if ptr == NULL, this is the tree id,
 246: **			otherwise this parameter is not supplied.
 247: **
 248: **	Returns:
 249: **		count of actual number of bytes read.
 250: **
 251: **	Side Effects:
 252: **		activity in database.
 253: **		static variables are adjusted correctly.  Note that
 254: **			this routine can be used on only one tree
 255: **			at one time.
 256: **
 257: **	Requires:
 258: **		Treedes -- a relation descriptor for the "tree" catalog
 259: **			open for read.
 260: **		clearkeys, setkey, getequal
 261: **
 262: **	Called By:
 263: **		readsym (indirectly via main)
 264: **
 265: **	Diagnostics:
 266: **		none
 267: **
 268: **	Syserrs:
 269: **		several access method error returns
 270: **		on initialization if the specified treeid is not
 271: **			in the catalog.
 272: */
 273: 
 274: relntrrd(ptr, cnt, treerelid, treeowner, treetype, treeid)
 275: char    *ptr;
 276: int cnt;
 277: char    *treerelid;
 278: char    *treeowner;
 279: char    treetype;
 280: int treeid;
 281: {
 282:     static struct tree  trseg;
 283:     static char     *trp;
 284:     static int      seqno;
 285:     register char       *p;
 286:     register int        n;
 287:     register int        i;
 288:     struct tree     trkey;
 289:     struct tup_id       tid;
 290: 
 291:     p = ptr;
 292:     n = cnt;
 293: 
 294:     if (p == NULL)
 295:     {
 296:         /* initialize -- make buffer appear empty */
 297:         trp = &trseg.treetree[sizeof trseg.treetree];
 298:         bmove(treerelid, trseg.treerelid, MAXNAME);
 299:         bmove(treeowner, trseg.treeowner, 2);
 300:         trseg.treetype = treetype;
 301:         trseg.treeid = treeid;
 302:         seqno = 0;
 303:         opencatalog("tree", 0);
 304: 
 305: #		ifdef xQTR2
 306:         if (tTf(70, 6))
 307:             printf("relntrrd: n=%.12s o=%.2s t=%d i=%d\n",
 308:                 treerelid, treeowner, treetype, treeid);
 309: #		endif
 310: 
 311:         return (0);
 312:     }
 313: 
 314:     /* fetch characters */
 315:     while (n-- > 0)
 316:     {
 317:         /* check for segment empty */
 318:         if (trp >= &trseg.treetree[sizeof trseg.treetree])
 319:         {
 320:             /* then read new segment */
 321:             clearkeys(&Treedes);
 322:             setkey(&Treedes, &trkey, &trseg.treerelid, TREERELID);
 323:             setkey(&Treedes, &trkey, &trseg.treeowner, TREEOWNER);
 324:             setkey(&Treedes, &trkey, &trseg.treetype, TREETYPE);
 325:             setkey(&Treedes, &trkey, &trseg.treeid, TREEID);
 326:             setkey(&Treedes, &trkey, &seqno, TREESEQ);
 327:             seqno++;
 328:             if ((i = getequal(&Treedes, &trkey, &trseg, &tid)) != 0)
 329:                 syserr("relnrdtr: getequal %d", i);
 330:             trp = &trseg.treetree[0];
 331:         }
 332: 
 333:         /* do actual character fetch */
 334:         *p++ = *trp++;
 335:     }
 336: 
 337:     return (cnt);
 338: }
 339: /*
 340: **  GETTREE -- get tree from 'tree' catalog
 341: **
 342: **	This function, given an internal treeid, fetches and builds
 343: **	that tree from the 'tree' catalog.  There is nothing exciting
 344: **	except the mapping of variables, done by mapvars().
 345: **
 346: **	Parameters:
 347: **		treeid -- internal id of tree to fetch and build.
 348: **		init -- passed to 'readqry' to tell whether or not
 349: **			to initialize the query buffer.
 350: **
 351: **	Returns:
 352: **		Pointer to root of tree.
 353: **
 354: **	Side Effects:
 355: **		file activity.  Space in Qbuf is used up.
 356: **
 357: **	Requires:
 358: **		relntrrd -- to initialize for readqry.
 359: **		readqry -- to read and build the tree.
 360: **		mapvars -- to change the varno's in the tree after
 361: **			built to avoid conflicts with variables in
 362: **			the original query.
 363: **
 364: **	Called By:
 365: **		view
 366: **		integrity (???)
 367: **		protect (???)
 368: **		d_view
 369: **
 370: **	Diagnostics:
 371: **		none
 372: **
 373: **	Syserrs:
 374: **		none
 375: */
 376: 
 377: QTREE *
 378: gettree(treerelid, treeowner, treetype, treeid, init)
 379: char    *treerelid;
 380: char    *treeowner;
 381: char    treetype;
 382: int treeid;
 383: int init;
 384: {
 385:     register QTREE  *t;
 386:     extern int  relntrrd();
 387:     register int    i;
 388: 
 389:     /* initialize relntrrd() for this treeid */
 390:     relntrrd(NULL, 0, treerelid, treeowner, treetype, treeid);
 391: 
 392:     /* read and build query tree */
 393:     t = readqry(&relntrrd, init);
 394: 
 395:     /* remap varno's to be unique */
 396:     if (!init)
 397:         mapvars(t);
 398: 
 399:     return (t);
 400: }

Defined functions

readqry defined in line 58; used 5 times
readsym defined in line 138; used 2 times
readtree defined in line 175; used 2 times
relntrrd defined in line 274; used 4 times

Defined variables

Last modified: 1995-02-19
Generated: 2016-12-26
Generated by src2html V0.67
page hit count: 1558
Valid CSS Valid XHTML 1.0 Strict