aboutsummaryrefslogblamecommitdiffstats
path: root/z33.c
blob: cf4fa76067b8ea6cc5c02bad9290fae6d17ee56d (plain) (tree)
1
2
3
4
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650

                                                                               
                                                                               
                                                                               
























































                                                                               
                                                                         








































                                                                              
                                        















                                                                               
                                        
















































































































































































































































































































































































































































































































































                                                                                
                                                        














































                                                                               
                                                                            

































































































































































                                                                                
/*@z33.c:Database Service:OldCrossDb(), NewCrossDb(), SymToNum()@*************/
/*                                                                           */
/*  THE LOUT DOCUMENT FORMATTING SYSTEM (VERSION 3.22)                       */
/*  COPYRIGHT (C) 1991, 2000 Jeffrey H. Kingston                             */
/*                                                                           */
/*  Jeffrey H. Kingston (jeff@cs.usyd.edu.au)                                */
/*  Basser Department of Computer Science                                    */
/*  The University of Sydney 2006                                            */
/*  AUSTRALIA                                                                */
/*                                                                           */
/*  This program is free software; you can redistribute it and/or modify     */
/*  it under the terms of the GNU General Public License as published by     */
/*  the Free Software Foundation; either Version 2, or (at your option)      */
/*  any later version.                                                       */
/*                                                                           */
/*  This program is distributed in the hope that it will be useful,          */
/*  but WITHOUT ANY WARRANTY; without even the implied warranty of           */
/*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            */
/*  GNU General Public License for more details.                             */
/*                                                                           */
/*  You should have received a copy of the GNU General Public License        */
/*  along with this program; if not, write to the Free Software              */
/*  Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA   */
/*                                                                           */
/*  FILE:         z33.c                                                      */
/*  MODULE:       Database Service                                           */
/*  EXTERNS:      OldCrossDb, NewCrossDb, DbCreate(), DbInsert(),            */
/*                DbConvert(), DbClose(), DbLoad(), DbRetrieve(),            */
/*                DbRetrieveNext()                                           */
/*                                                                           */
/*****************************************************************************/
#define INIT_DBCHECK_NUM	107
#include "externs.h"


/*****************************************************************************/
/*                                                                           */
/*  DBCHECK_TABLE                                                            */
/*                                                                           */
/*  A symbol table holding all non-galley cross references, basically        */
/*  implementing a function (sym, tag) -> fpos (if any).                     */
/*                                                                           */
/*     dtab_new(newsize)                New empty table, newsize capacity    */
/*     dtab_insert(x, S)                Insert new (sym, tag) pair x into S  */
/*     dtab_retrieve(sym, tag, S)       Retrieve (sym, tag) pair from S      */
/*     dtab_debug(S, fp)                Debug print of table S to file fp    */
/*                                                                           */
/*****************************************************************************/

typedef struct
{ int dbchecktab_size;				/* size of table             */
  int dbchecktab_count;				/* number of objects held    */
  OBJECT dbchecktab_item[1];
} *DBCHECK_TABLE;

#define	dtab_size(S)	(S)->dbchecktab_size
#define	dtab_count(S)	(S)->dbchecktab_count
#define	dtab_item(S, i)	(S)->dbchecktab_item[i]

#define hash(pos, sym, tag, S)						\
{ FULL_CHAR *p = tag;							\
  pos = (unsigned long) sym;						\
  while( *p ) pos += *p++;						\
  pos = pos % dtab_size(S);						\
}

static DBCHECK_TABLE dtab_new(int newsize)
{ DBCHECK_TABLE S;  int i;
  ifdebug(DMA, D, DebugRegisterUsage(MEM_DBCHECK, 1,
    2*sizeof(int) + newsize * sizeof(OBJECT)));
  S = (DBCHECK_TABLE)
	  malloc(2*sizeof(int) + newsize * sizeof(OBJECT));
  if( S == (DBCHECK_TABLE) NULL )
    Error(33, 1, "run out of memory enlarging dbcheck table", FATAL, no_fpos);
  dtab_size(S) = newsize;
  dtab_count(S) = 0;
  for( i = 0;  i < newsize;  i++ )  dtab_item(S, i) = nilobj;
  return S;
} /* end dtab_new */

static void dtab_insert(OBJECT x, DBCHECK_TABLE *S);

static DBCHECK_TABLE dtab_rehash(DBCHECK_TABLE S, int newsize)
{ DBCHECK_TABLE NewS;  int i;  OBJECT link, z;
  NewS = dtab_new(newsize);
  for( i = 0;  i < dtab_size(S);  i++ )
  { if( dtab_item(S, i) != nilobj )
    { OBJECT ent = dtab_item(S, i);
      assert( type(ent) == ACAT, "dtab_rehash: ACAT!" );
      for( link = Down(ent);  link != ent;  link = NextDown(link) )
      { Child(z, link);
	dtab_insert(z, &NewS);
      }
      DisposeObject(ent);
    }
  }
  ifdebug(DMA, D, DebugRegisterUsage(MEM_DBCHECK, -1,
    -(2*sizeof(int) + dtab_size(S) * sizeof(OBJECT))));
  free(S);
  return NewS;
} /* end dtab_rehash */

static void dtab_insert(OBJECT x, DBCHECK_TABLE *S)
{ unsigned long pos;  OBJECT z, link, y;
  if( dtab_count(*S) == dtab_size(*S) - 1 )	/* one less since 0 unused */
    *S = dtab_rehash(*S, 2*dtab_size(*S));
  dtab_count(*S)++;
  hash(pos, db_checksym(x), string(x), *S);
  if( dtab_item(*S, pos) == nilobj )  New(dtab_item(*S, pos), ACAT);
  z = dtab_item(*S, pos);
  for( link = Down(z);  link != z;  link = NextDown(link) )
  { Child(y, link);
    if( db_checksym(x) == db_checksym(y) && StringEqual(string(x), string(y)) )
    { assert(FALSE, "Dbcheck: entry inserted twice");
    }
  }
  Link(dtab_item(*S, pos), x);
} /* end dtab_insert */

static OBJECT dtab_retrieve(OBJECT sym, FULL_CHAR *tag, DBCHECK_TABLE S)
{ OBJECT x, link, y;  unsigned long pos;
  hash(pos, sym, tag, S);
  x = dtab_item(S, pos);
  if( x == nilobj )  return nilobj;
  for( link = Down(x);  link != x;  link = NextDown(link) )
  { Child(y, link);
    if( sym == db_checksym(y) && StringEqual(tag, string(y)) )
      return y;
  }
  return nilobj;
} /* end dtab_retrieve */

#if DEBUG_ON
static void dtab_debug(DBCHECK_TABLE S, FILE *fp)
{ int i;  OBJECT x, link, y;
  fprintf(fp, "  table size: %d;  current number of items: %d\n",
    dtab_size(S), dtab_count(S));
  for( i = 0;  i < dtab_size(S);  i++ )
  { x = dtab_item(S, i);
    fprintf(fp, "dtab_item(S, %d) =", i);
    if( x == nilobj )
      fprintf(fp, " <nilobj>");
    else if( type(x) != ACAT )
      fprintf(fp, " not ACAT!");
    else for( link = Down(x);  link != x;  link = NextDown(link) )
    { Child(y, link);
      fprintf(fp, " %s&&%s",
	is_word(type(y)) ? SymName(db_checksym(y)) : AsciiToFull("?"),
	is_word(type(y)) ? string(y) : AsciiToFull("not-WORD!"));
    }
    fprintf(fp, "\n");
  }
} /* end dtab_debug */
#endif

static DBCHECK_TABLE DbCheckTable;		/* the dbcheck table         */
static BOOLEAN	     DbCheckTableInit = FALSE;	/* TRUE if table inited	     */


/*****************************************************************************/
/*                                                                           */
/*  OldCrossDb     Database containing cross references from previous run.   */
/*  NewCrossDb     Writable database of cross references from this run.      */
/*                                                                           */
/*****************************************************************************/

OBJECT OldCrossDb, NewCrossDb;


/*****************************************************************************/
/*                                                                           */
/*  #define SymToNum(db, sym, num, gall)                                     */
/*                                                                           */
/*  Set num to the number used to refer to sym in database db.  If sym is    */
/*  not currently referred to in db, create a new number and record sym.     */
/*  If gall is true, sym is the target of galleys stored in this database.   */
/*  Store in boolean fields db_targ(link) and is_extern_target(sym).         */
/*                                                                           */
/*****************************************************************************/

#define SymToNum(db, sym, num, gall)					\
{ OBJECT link, yy;  int count;						\
  count = 0;								\
  for( link = Down(db);  link != db;  link = NextDown(link) )		\
  { Child(yy, link);							\
    assert(type(yy)==CROSS_SYM || type(yy)==ACAT, "SymToNum: yy!");	\
    if( type(yy) != CROSS_SYM )  continue;				\
    if( symb(yy) == sym )  break;					\
    if( number(link) > count )  count = number(link);			\
  }									\
  if( link == db )							\
  { if( cross_sym(sym) == nilobj )  CrossInit(sym);			\
    Link(db, cross_sym(sym));						\
    link = LastDown(db);						\
    number(link) = count + 1;						\
    db_targ(link) = FALSE;						\
  }									\
  num = number(link);							\
  if( gall )  db_targ(link) = is_extern_target(sym) =			\
				uses_extern_target(sym) = TRUE;		\
} /* end SymToNum */


/*@::NumToSym(), DbCreate()@**************************************************/
/*                                                                           */
/*  #define NumToSym(db, num, sym)                                           */
/*                                                                           */
/*  Set sym to the symbol which is referred to in database db by num.        */
/*                                                                           */
/*****************************************************************************/

#define NumToSym(db, num, sym)						\
{ OBJECT link, y;							\
  for( link = Down(db);  link != db;  link = NextDown(link) )		\
  { Child(y, link);							\
    if( type(y) == CROSS_SYM && number(link) == num )  break;		\
  }									\
  assert( link != db, "NumToSym: no sym");				\
  assert( type(y) == CROSS_SYM, "NumToSym: y!" );			\
  sym = symb(y);							\
} /* end NumToSym */


/*****************************************************************************/
/*                                                                           */
/*  OBJECT DbCreate(x)                                                       */
/*                                                                           */
/*  Create a new writable database with name (i.e. file stem) x and file     */
/*  position fpos for error messages.                                        */
/*                                                                           */
/*****************************************************************************/

OBJECT DbCreate(OBJECT x)
{ OBJECT db = x;
  debug1(DBS, DD, "DbCreate(%s)", string(db));
  assert( is_word(type(x)), "DbCreate: !is_word(type(x))" );
  reading(db) = FALSE;  db_filep(db) = null;
  debug1(DBS, DD, "DbCreate returning %s", EchoObject(db));
  return db;
} /* end DbCreate */


/*@::DbInsert()@**************************************************************/
/*                                                                           */
/*  DbInsert(db, gall, sym, tag, tagfpos, seq, dfnum, dlnum, dfpos)          */
/*                                                                           */
/*  Insert a new entry into writable database db.  The primary key of the    */
/*  entry has these three parts:                                             */
/*                                                                           */
/*      gall        TRUE if inserting a galley                               */
/*      sym         The symbol which is the target of this entry             */
/*      tag         The tag of this target (must be a non-null string)       */
/*                                                                           */
/*  tagfpos is the file position that the tag originated from.               */
/*  There is also an auxiliary key, seq, which enforces an ordering on       */
/*  entries with equal primary keys but is not itself ever retrieved.  This  */
/*  ordering is used for sorted galleys.  The value of the entry has the     */
/*  following parts:                                                         */
/*                                                                           */
/*      dfnum       The file containing the object                           */
/*      dfpos       The position of the object in that file                  */
/*      dlnum       The line number of the object in the file                */
/*                                                                           */
/*  If check is TRUE, we need to check whether an entry with this key has    */
/*  been inserted before.  This will never be the case with galley entries.  */
/*                                                                           */
/*****************************************************************************/

void DbInsert(OBJECT db, BOOLEAN gall, OBJECT sym, FULL_CHAR *tag,
FILE_POS *tagfpos, FULL_CHAR *seq, FILE_NUM dfnum, long dfpos, int dlnum,
BOOLEAN check)
{ int symnum;  OBJECT chk;
  static int extra_seq = 0;
  FULL_CHAR buff[MAX_BUFF];
  assert( is_word(type(db)), "DbInsert: db!" );
  assert( tag[0] != '\0', "DbInsert: null tag!" );
  assert( seq[0] != '\0', "DbInsert: null seq!" );
  ifdebug(DPP, D, ProfileOn("DbInsert"));
  debug6(DBS, D, "DbInsert(%s, %s, %s, %s, %s, %s, dlnum, dfpos)",
	string(db), bool(gall), SymName(sym), tag, seq,
	dfnum == NO_FILE ? AsciiToFull(".") : FileName(dfnum));
  assert(!reading(db), "DbInsert: insert into reading database");

  /* if required, check that (sym, tag) not already inserted */
  if( check )
  { 
    debug2(DBS, DD, "  checking %s&&%s, DbCheckTable =", SymName(sym), tag);
    if( !DbCheckTableInit )
    { DbCheckTable = dtab_new(INIT_DBCHECK_NUM);
      DbCheckTableInit = TRUE;
    }
    ifdebug(DBS, DD, dtab_debug(DbCheckTable, stderr));
    chk = dtab_retrieve(sym, tag, DbCheckTable);
    if( chk == nilobj )
    { chk = MakeWord(WORD, tag, tagfpos);
      db_checksym(chk) = sym;
      dtab_insert(chk, &DbCheckTable);
    }
    else
    { if( file_num(fpos(chk)) > 0 )
        Error(33, 4, "cross reference %s&&%s used previously, at%s",
          WARN, tagfpos, SymName(sym), tag, EchoFilePos(&fpos(chk)));
      else Error(33, 5, "cross reference %s&&%s used previously",
	  WARN, tagfpos, SymName(sym), tag);
    }
  }

  /* open database index file if not already done */
  if( db_filep(db) == null )
  { if( StringLength(string(db)) + StringLength(NEW_INDEX_SUFFIX) >= MAX_BUFF )
      Error(33, 2, "database file name %s%s is too long",
	FATAL, no_fpos, string(db), NEW_INDEX_SUFFIX);
    StringCopy(buff, string(db));
    StringCat(buff, NEW_INDEX_SUFFIX);
    db_filep(db) = StringFOpen(buff, WRITE_BINARY);
    if( db_filep(db) == null )
      Error(33, 3, "cannot write to database file %s", FATAL, &fpos(db), buff);
  }

  /* work out database index file entry and append it to file */
  if( dfnum != NO_FILE )
  { StringCopy(buff, FileName(dfnum));
    StringCopy(&buff[StringLength(buff)-StringLength(DATA_SUFFIX)], STR_EMPTY);
  }
  else StringCopy(buff, AsciiToFull("."));
  SymToNum(db, sym, symnum, gall);
  ifdebug(DBS, DD,
  fprintf(stderr, "  -> %s%d&%s\t%s\t%ld\t%d\t%s\n", gall ? "0" : "", symnum,
    tag, seq, dfpos, dlnum, buff);
  );
  fprintf(db_filep(db), "%s%d&%s\t%s\t%s\t%ld\t%d\t%s\n", gall ? "0" : "",
    symnum, tag, seq, StringFiveInt(++extra_seq), dfpos, dlnum, buff);

  /* return */
  debug0(DBS, DD, "DbInsert returning.");
  ifdebug(DPP, D, ProfileOff("DbInsert"));
} /* end DbInsert */


/*@::DbConvert(), DbClose()@**************************************************/
/*                                                                           */
/*  DbConvert(db, full_name)                                                 */
/*                                                                           */
/*  Convert database db from writable to readable, then dispose it.          */
/*  full_name is TRUE if symbols are to be known by their full path name.    */
/*                                                                           */
/*****************************************************************************/

void DbConvert(OBJECT db, BOOLEAN full_name)
{ FULL_CHAR oldname[MAX_BUFF+10], newname[MAX_BUFF];
  OBJECT link, y;
  ifdebug(DPP, D, ProfileOn("DbConvert"));
  debug2(DBS, DD, "DbConvert( %ld %s )", (long) db, string(db));
  assert( !reading(db), "DbConvert: reading database");
  StringCopy(newname, string(db));
  StringCat(newname, INDEX_SUFFIX);
  StringCopy(oldname, string(db));
  StringCat(oldname, NEW_INDEX_SUFFIX);
  if( db_filep(db) != null )
  {
    fprintf(db_filep(db), "00 %s %s\n", LOUT_VERSION, "database index file");
    for( link = Down(db);  link != db;  link = NextDown(link) )
    { Child(y, link);
      assert( type(y) == CROSS_SYM || type(y) == ACAT, "DbConvert: y!" );
      if( type(y) != CROSS_SYM )  continue;
      fprintf(db_filep(db), "%s %d %s\n",
	db_targ(link) ? "00target" : "00symbol",
	number(link),
	full_name ? FullSymName(symb(y), AsciiToFull(" ")) : SymName(symb(y)));
    }
    fclose(db_filep(db));
    debug2(DBS, DD, "  calling SortFile(%s, %s)", oldname, newname);
    SortFile(oldname, newname);
  }
  else StringRemove(newname);
  StringRemove(oldname);
  DeleteNode(db);
  debug0(DBS, DD, "DbConvert returning.");
  ifdebug(DPP, D, ProfileOff("DbConvert"));
} /* end DbConvert */


/*****************************************************************************/
/*                                                                           */
/*  DbClose(db)                                                              */
/*                                                                           */
/*  Close readable database db.                                              */
/*                                                                           */
/*****************************************************************************/

void DbClose(OBJECT db)
{ if( db != nilobj && !in_memory(db) && db_filep(db) != NULL )
  {  fclose(db_filep(db));
     db_filep(db) = NULL;
  }
} /* end DbClose */


/*@::DbLoad()@****************************************************************/
/*                                                                           */
/*  OBJECT DbLoad(stem, fpath, create, symbs, in_mem)                        */
/*                                                                           */
/*  Open for reading the database whose index file name is string(stem).li.  */
/*  This file has not yet been defined; its search path is fpath.  If it     */
/*  will not open and create is true, try creating it from string(stem).ld.  */
/*                                                                           */
/*  symbs is an ACAT of CLOSUREs showing the symbols that the database may   */
/*  contain; or nilobj if the database may contain any symbol.               */
/*                                                                           */
/*  If in_mem is true, this database index is to be kept in internal memory, */
/*  rather than an external file, as a speed optimization.                   */
/*                                                                           */
/*****************************************************************************/

OBJECT DbLoad(OBJECT stem, int fpath, BOOLEAN create, OBJECT symbs,
  BOOLEAN in_mem)
{ FILE *fp;  OBJECT db, t, res, tag, par, sym, link, y;
  int i, lnum, dlnum, num, count, leftp;
  FILE_NUM index_fnum, dfnum;  long dfpos;
  BOOLEAN gall;  FULL_CHAR line[MAX_BUFF], sym_name[MAX_BUFF]; char *gotline;
  ifdebug(DPP, D, ProfileOn("DbLoad"));
  debug3(DBS, DD, "[ DbLoad(%s, %d, %s, -)", string(stem), fpath, bool(create));

  /* open or else create index file fp */
  debug0(DFS, D, "  calling DefineFile from DbLoad (1)");
  index_fnum = DefineFile(string(stem), INDEX_SUFFIX, &fpos(stem), INDEX_FILE,
		 fpath);
  fp = OpenFile(index_fnum, create, FALSE);

  /* read first line of database index file, which should have the version */
  if( fp != null )
  { if( StringFGets(line, MAX_BUFF, fp) == NULL ||
        !StringBeginsWith(&line[3], LOUT_VERSION) )
    {
      /* out of date, pretend it isn't there at all */
      StringRemove(FileName(index_fnum));
      fp = null;
    }
  }

  if( fp == null && create )
  { db = nilobj;
    debug0(DFS, D, "  calling DefineFile from DbLoad (2)");
    dfnum = DefineFile(string(stem), DATA_SUFFIX, &fpos(stem),
      DATABASE_FILE, DATABASE_PATH);
    dfpos = 0L;  LexPush(dfnum, 0, DATABASE_FILE, 1, FALSE);
    t = LexGetToken();
    dlnum = line_num(fpos(t));
    while( type(t) == LBR )
    { res = Parse(&t, StartSym, FALSE, FALSE);
      if( t != nilobj || type(res) != CLOSURE )
	Error(33, 6, "syntax error in database file %s",
	  FATAL, &fpos(res), FileName(dfnum));
      assert( symbs != nilobj, "DbLoad: create && symbs == nilobj!" );
      if( symbs != nilobj )
      {	for( link = Down(symbs);  link != symbs;  link = NextDown(link) )
	{ Child(y, link);
	  if( type(y) == CLOSURE && actual(y) == actual(res) )  break;
	}
	if( link == symbs )
	  Error(33, 7, "%s found in database but not declared in %s line",
	    FATAL, &fpos(res), SymName(actual(res)), KW_DATABASE);
      }
      for( tag = nilobj, link = Down(res); link != res; link = NextDown(link) )
      {	Child(par, link);
	if( type(par) == PAR && is_tag(actual(par)) && Down(par) != par )
	{ Child(tag, Down(par));
	  break;
	}
      }
      if( tag == nilobj )
	Error(33, 8, "database symbol %s has no tag",
	  FATAL, &fpos(res), SymName(actual(res)));
      tag = ReplaceWithTidy(tag, TRUE);  /* && */
      if( !is_word(type(tag)) )
	Error(33, 9, "database symbol tag is not a simple word",
	  FATAL, &fpos(res));
      if( StringEqual(string(tag), STR_EMPTY) )
	Error(33, 10, "database symbol tag is an empty word", FATAL,&fpos(res));
      if( db == nilobj )
      {	StringCopy(line, FileName(dfnum));
	i = StringLength(line) - StringLength(INDEX_SUFFIX);
	assert( i > 0, "DbLoad: FileName(dfnum) (1)!" );
	StringCopy(&line[i], STR_EMPTY);
	db = DbCreate(MakeWord(WORD, line, &fpos(stem)));
      }
      DbInsert(db, FALSE, actual(res), string(tag), &fpos(tag), STR_ZERO,
	NO_FILE, dfpos, dlnum, TRUE);
      DisposeObject(res);  dfpos = LexNextTokenPos();  t = LexGetToken();
      dlnum = line_num(fpos(t));
    }
    if( type(t) != END )
      Error(33, 11, "%s or end of file expected here", FATAL, &fpos(t), KW_LBR);
    LexPop();
    if( db == nilobj )
    { StringCopy(line, FileName(dfnum));
      i = StringLength(line) - StringLength(INDEX_SUFFIX);
      assert( i > 0, "DbLoad: FileName(dfnum) (2)!" );
      StringCopy(&line[i], STR_EMPTY);
      db = DbCreate(MakeWord(WORD, line, &fpos(stem)));
    }
    DbConvert(db, FALSE);
    if( (fp = OpenFile(index_fnum, FALSE, FALSE)) == null ||
        StringFGets(line, MAX_BUFF, fp) == NULL ||
        !StringBeginsWith(&line[3], LOUT_VERSION) )
      Error(33, 12, "cannot open database file %s",
        FATAL, &fpos(db), FileName(index_fnum));
  }

  /* set up database record */
  StringCopy(line, FileName(index_fnum));
  i = StringLength(line) - StringLength(INDEX_SUFFIX);
  assert( i > 0, "DbLoad: FileName(index_fnum)!" );
  StringCopy(&line[i], STR_EMPTY);
  db = MakeWord(WORD, line, &fpos(stem));
  reading(db) = TRUE;
  in_memory(db) = in_mem;
  if( symbs != nilobj )
  { assert( type(symbs) == ACAT, "DbLoad: type(symbs)!" );
    Link(db, symbs);
  }
  if( fp == null )
  { debug1(DBS, DD, "] DbLoad returning (empty) %s", string(db));
    db_filep(db) = null;
    db_lines(db) = (LINE *) NULL;
    ifdebug(DPP, D, ProfileOff("DbLoad"));
    return db;
  }

  /* read header lines of index file, find its symbols */
  leftp = 0;  lnum = 1;
  gotline = StringFGets(line, MAX_BUFF, fp);
  while( gotline != NULL )
  {
    if( line[0] != '0' || line[1] != '0' )  break;
    lnum++;
    leftp = (int) ftell(fp);
    gall = StringBeginsWith(line, AsciiToFull("00target "));
    sscanf( (char *) line, gall ? "00target %d" : "00symbol %d", &num);
    for( i = 9;  line[i] != CH_SPACE && line[i] != '\0';  i++ );
    if( symbs == nilobj )
    {
      /* any symbols are possible, full path names in index file required */
      count = 0;  sym = StartSym;
      while( line[i] != CH_NEWLINE && line[i] != '\0' )
      {	PushScope(sym, FALSE, FALSE);  count++;
	sscanf( (char *) &line[i+1], "%s", sym_name);
	sym = SearchSym(sym_name, StringLength(sym_name));
	i += StringLength(sym_name) + 1;
      }
      for( i = 1;  i <= count;  i++ )  PopScope();
    }
    else
    {
      /* only symbs symbols possible, full path names not required */
      sym = nilobj;
      sscanf( (char *) &line[i+1], "%s", sym_name);
      for( link = Down(symbs);  link != symbs;  link = NextDown(link) )
      {	Child(y, link);
	assert( type(y) == CLOSURE, "DbLoad: type(y) != CLOSURE!" );
	if( StringEqual(sym_name, SymName(actual(y))) )
	{ sym = actual(y);
	  break;
	}
      }
    }
    if( sym != nilobj && sym != StartSym )
    { if( cross_sym(sym) == nilobj )  CrossInit(sym);
      Link(db, cross_sym(sym));
      link = LastDown(db);
      number(link) = num;  db_targ(link) = gall;
      if( gall )  is_extern_target(sym) = uses_extern_target(sym) = TRUE;
    }
    else
    { Error(33, 13, "undefined symbol in database file %s (line %d)",
	WARN, &fpos(db), FileName(index_fnum), lnum);
      debug1(DBS, DD, "] DbLoad returning %s (error)", string(db));
      fclose(fp);
      in_memory(db) = FALSE;
      db_filep(db) = null;  /* subsequently treated like an empty database */
      ifdebug(DPP, D, ProfileOff("DbLoad"));
      return db;
    }
    gotline = StringFGets(line, MAX_BUFF, fp);
  }

  /* if in_memory, go on to read the entire database index into memory */
  if( in_memory(db) )
  { int len;
    if( gotline == NULL )
      db_lines(db) = 0;
    else
    {
      db_lines(db) = ReadLines(fp, FileName(index_fnum), line, &len);
      db_lineslen(db) = len;
      SortLines(db_lines(db), db_lineslen(db));
    }
  }
  else /* external, save leftpos and file pointer */
  { db_filep(db) = fp;
    left_pos(db) = leftp;
  }

  /* return */
  debug1(DBS, DD, "] DbLoad returning %s", string(db));
  ifdebug(DPP, D, ProfileOff("DbLoad"));
  return db;
} /* end DbLoad */


/*@::SearchFile()@************************************************************/
/*                                                                           */
/*  static BOOLEAN SearchFile(fp, left, right, str, line)                    */
/*                                                                           */
/*  File fp is a text file.  left is the beginning of a line, right is the   */
/*  end of a line.   Search the file by binary search for a line beginning   */
/*  with str.  If found, return it in line, else return FALSE.               */
/*                                                                           */
/*****************************************************************************/

static BOOLEAN SearchFile(FILE *fp, int left, int right,
FULL_CHAR *str, FULL_CHAR *line)
{ int l, r, mid, mid_end;  FULL_CHAR buff[MAX_BUFF];  BOOLEAN res;
  ifdebug(DPP, D, ProfileOn("SearchFile"));
  debug3(DBS, DD, "SearchFile(fp, %d, %d, %s, line)", left, right, str);

  l = left;  r = right;
  while( l <= r )
  {
    /* loop invt: (l==0 or fp[l-1]==CH_NEWLINE) and (fp[r] == CH_NEWLINE)    */
    /* and first key >= str lies in the range fp[l..r+1]                     */

    /* find line near middle of the range; mid..mid_end brackets it */
    debug2(DBS, DD, "  start loop: l = %d, r = %d", l, r);
    mid = (l + r)/2;
    fseek(fp, (long) mid, SEEK_SET);
    do { mid++; } while( getc(fp) != CH_NEWLINE );
    if( mid == r + 1 )
    { mid = l;
      fseek(fp, (long) mid, SEEK_SET);
    }
    StringFGets(line, MAX_BUFF, fp);
    mid_end = (int) ftell(fp) - 1;
    debug3(DBS, DD, "  mid: %d, mid_end: %d, line: %s", mid, mid_end, line);
    assert( l <= mid,      "SearchFile: l > mid!"        );
    assert( mid < mid_end, "SearchFile: mid >= mid_end!" );
    assert( mid_end <= r,  "SearchFile: mid_end > r!"    );

    /* compare str with this line and prepare next step */
    debug2(DBS, DD, "  comparing key %s with line %s", str, line);
    if( TabbedStringLessEqual(str, line) )  r = mid - 1;
    else l = mid_end + 1;
  } /* end while */

  /* now first key >= str lies in fp[l]; compare it with str */
  if( l < right )
  { fseek(fp, (long) l, SEEK_SET);
    StringFGets(line, MAX_BUFF, fp);
    sscanf( (char *) line, "%[^\t]", buff);
    res = StringEqual(str, buff);
  }
  else res = FALSE;
  debug1(DBS, DD, "SearchFile returning %s", bool(res));
  ifdebug(DPP, D, ProfileOff("SearchFile"));
  return res;
} /* end SearchFile */


/*@::SearchLines()@***********************************************************/
/*                                                                           */
/*  static BOOLEAN SearchLines(LINE *lines, int left, int right, str, lnum)  */
/*                                                                           */
/*  Search the sorted array of LINE arrays lines[left..right] for a line     */
/*  beginning with str, and return TRUE if found else FALSE.                 */
/*                                                                           */
/*  If TRUE is returned then the number of the line is in *lnum.             */
/*                                                                           */
/*****************************************************************************/

static BOOLEAN SearchLines(LINE *lines, int left, int right, FULL_CHAR *str,
  int *lnum)
{ int l, r, mid;  FULL_CHAR buff[MAX_BUFF];
  BOOLEAN res;
  debug3(DBS, D, "SearchLines(lines, %d, %d, %s, lnum)", left, right, str);
  if( right < left )
  {
    debug0(DBS, D, "SearchLines returning FALSE (empty lines)");
    return FALSE;
  }
  l = left;
  r = right - 1;
  while( l <= r )
  {
    /* loop invt: first key >= str (if any) lies in the range lines[l..r+1] */
    /* and left <= l <= right and r < right                                 */
    mid = (l + r) / 2;
    debug4(DBS, D, "  [l %d, r %d] examining lines[%d] = %s", l, r, mid,
      lines[mid]);
    if( TabbedStringLessEqual(str, (FULL_CHAR *) lines[mid]) )  r = mid - 1;
    else l = mid + 1;
  }
  sscanf( (char *) lines[l], "%[^\t]", buff);
  if( StringEqual(str, buff) )
  {
    res = TRUE;
    *lnum = l;
    debug1(DBS, D, "SearchLines returning TRUE (lnum %d)", *lnum);
  }
  else
  { res = FALSE;
    debug0(DBS, D, "SearchLines returning FALSE");
  }
  return res;
} /* end SearchLines */


/*@::DbRetrieve()@************************************************************/
/*                                                                           */
/*  BOOLEAN DbRetrieve(db, gall, sym, tag, seq, dfnum, dfpos, dlnum, cont)   */
/*                                                                           */
/*  Retrieve the first entry of database db with the given gall, sym and     */
/*  tag.  Set *seq, *dfnum, *dlnum, *dfpos to the associated value.          */
/*  Set *cont to a private value for passing to DbRetrieveNext.              */
/*                                                                           */
/*****************************************************************************/

BOOLEAN DbRetrieve(OBJECT db, BOOLEAN gall, OBJECT sym, FULL_CHAR *tag,
  FULL_CHAR *seq, FILE_NUM *dfnum, long *dfpos, int *dlnum, long *cont)
{ int symnum, lnum;  FULL_CHAR line[MAX_BUFF], buff[MAX_BUFF];
  ifdebug(DPP, D, ProfileOn("DbRetrieve"));
  debug4(DBS, DD, "DbRetrieve(%s, %s%s&%s)", string(db), gall ? "0" : "",
	SymName(sym), tag);

  /* check OK to proceed */
  if( !reading(db) || db_filep(db) == null )
  { debug0(DBS, DD, "DbRetrieve returning FALSE (empty or not reading)");
    ifdebug(DPP, D, ProfileOff("DbRetrieve"));
    return FALSE;
  }

  /* convert parameters into search key */
  SymToNum(db, sym, symnum, FALSE);
  sprintf( (char *) buff, "%s%d&%s", gall ? "0" : "", symnum, tag);

  if( in_memory(db) )
  {
    /* search internal table, return if not found; set *cont to continuation */
    if( !SearchLines(db_lines(db), 0, db_lineslen(db) - 1, buff, &lnum) )
    { debug0(DBS, DD, "DbRetrieve returning FALSE (key not present)");
      ifdebug(DPP, D, ProfileOff("DbRetrieve"));
      return FALSE;
    }
    sscanf( (char *) db_lines(db)[lnum],
      "%*[^\t]\t%[^\t]\t%*[^\t]\t%ld\t%d\t%[^\n]", seq, dfpos, dlnum, buff);
    *cont = lnum+1;
  }
  else
  {
    /* search for key in file, return if not found; set *cont to continuatn */
    fseek(db_filep(db), 0L, SEEK_END);
    if( !SearchFile(db_filep(db), (int) left_pos(db),
	   (int) ftell(db_filep(db)) - 1, buff, line) )
    { debug0(DBS, DD, "DbRetrieve returning FALSE (key not present)");
      ifdebug(DPP, D, ProfileOff("DbRetrieve"));
      return FALSE;
    }
    sscanf( (char *) line,
      "%*[^\t]\t%[^\t]\t%*[^\t]\t%ld\t%d\t%[^\n]", seq, dfpos, dlnum, buff);
    *cont = ftell(db_filep(db));
  }

  /* work out file name if . abbreviation used, and possibly define file */
  if( StringEqual(buff, AsciiToFull(".")) )
  { StringCopy(buff, string(db));
  }
  *dfnum = FileNum(buff, DATA_SUFFIX);
  if( *dfnum == NO_FILE )  /* can only occur in cross reference database */
  { debug0(DFS, D, "  calling DefineFile from DbRetrieve");
    *dfnum = DefineFile(buff, DATA_SUFFIX, &fpos(db),
      DATABASE_FILE, SOURCE_PATH);
  }

  /* return */
  debug3(DBS, DD, "DbRetrieve returning TRUE (in %s at %ld, line %d)",
    FileName(*dfnum), *dfpos, *dlnum);
  ifdebug(DPP, D, ProfileOff("DbRetrieve"));
  return TRUE;
} /* end DbRetrieve */


/*@::DbRetrieveNext()@********************************************************/
/*                                                                           */
/*  BOOLEAN DbRetrieveNext(db, gall, sym, tag, seq, dfnum, dfpos,dlnum,cont) */
/*                                                                           */
/*  Retrieve the entry of database db pointed to by *cont.                   */
/*  Set *gall, *sym, *tag, *seq, *dfnum, *dlnum, *dfpos to the value.        */
/*  Reset *cont to the next entry for passing to the next DbRetrieveNext.    */
/*                                                                           */
/*****************************************************************************/

BOOLEAN DbRetrieveNext(OBJECT db, BOOLEAN *gall, OBJECT *sym, FULL_CHAR *tag,
  FULL_CHAR *seq, FILE_NUM *dfnum, long *dfpos, int *dlnum, long *cont)
{ FULL_CHAR line[MAX_BUFF], *cline, fname[MAX_BUFF]; int symnum;
  ifdebug(DPP, D, ProfileOn("DbRetrieveNext"));
  debug2(DBS, DD, "DbRetrieveNext( %s, %ld )", string(db), *cont);
  assert(reading(db), "DbRetrieveNext: not reading");

  /* check OK to proceed */
  if( db_filep(db) == null )
  { debug0(DBS, DD, "DbRetrieveNext returning FALSE (empty database)");
    ifdebug(DPP, D, ProfileOff("DbRetrieveNext"));
    return FALSE;
  }

  if( in_memory(db) )
  {
    /* get next entry from internal database */
    if( *cont >= db_lineslen(db) )
    { debug0(DBS, DD, "DbRetrieveNext returning FALSE (no successor)");
      ifdebug(DPP, D, ProfileOff("DbRetrieveNext"));
      return FALSE;
    }
    cline = (FULL_CHAR *) db_lines(db)[*cont];
    *gall = (cline[0] == '0' ? 1 : 0);
    sscanf((char *)&cline[*gall], "%d&%[^\t]\t%[^\t]\t%*[^\t]\t%ld\t%d\t%[^\n]",
      &symnum, tag, seq, dfpos, dlnum, fname);
    *cont = *cont + 1;
  }
  else
  {
    /* use *cont to find position of next entry; advance *cont */
    fseek(db_filep(db), *cont == 0L ? (long) left_pos(db) : *cont, SEEK_SET);
    if( StringFGets(line, MAX_BUFF, db_filep(db)) == NULL )
    { debug0(DBS, DD, "DbRetrieveNext returning FALSE (no successor)");
      ifdebug(DPP, D, ProfileOff("DbRetrieveNext"));
      return FALSE;
    }
    *gall = (line[0] == '0' ? 1 : 0);
    sscanf((char *)&line[*gall], "%d&%[^\t]\t%[^\t]\t%*[^\t]\t%ld\t%d\t%[^\n]",
      &symnum, tag, seq, dfpos, dlnum, fname);
    *cont = ftell(db_filep(db));
  }

  /* work out file name if . abbreviation used, and possibly define file */
  if( StringEqual(fname, AsciiToFull(".")) )
  { StringCopy(fname, string(db));
  }
  *dfnum = FileNum(fname, DATA_SUFFIX);
  if( *dfnum == NO_FILE )  /* can only occur in cross reference database */
  { debug0(DFS, D, "  calling DefineFile from DbRetrieveNext");
    *dfnum = DefineFile(fname, DATA_SUFFIX, &fpos(db),
      DATABASE_FILE, SOURCE_PATH);
  }
  NumToSym(db, symnum, *sym);

  /* return */
  debug3(DBS, DD, "DbRetrieveNext returning TRUE (in %s at %ld, line %d)",
    FileName(*dfnum), *dfpos, *dlnum);
  ifdebug(DPP, D, ProfileOff("DbRetrieveNext"));
  return TRUE;
} /* end DbRetrieveNext */