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root/radiance/ray/src/rt/ambient.c
Revision: 2.112
Committed: Mon Mar 7 17:52:14 2022 UTC (2 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.111: +9 -206 lines
Log Message:
perf(rtrace,rpict,rvu): Removed ambient value sorting, which had issues

File Contents

# Content
1 static const char RCSid[] = "$Id: ambient.c,v 2.111 2021/11/18 19:38:21 greg Exp $";
2 /*
3 * ambient.c - routines dealing with ambient (inter-reflected) component.
4 *
5 * Declarations of external symbols in ambient.h
6 */
7
8 #include "copyright.h"
9
10 #include <string.h>
11
12 #include "platform.h"
13 #include "ray.h"
14 #include "otypes.h"
15 #include "otspecial.h"
16 #include "resolu.h"
17 #include "ambient.h"
18 #include "random.h"
19 #include "pmapamb.h"
20
21 #ifndef OCTSCALE
22 #define OCTSCALE 1.0 /* ceil((valid rad.)/(cube size)) */
23 #endif
24
25 extern char *shm_boundary; /* memory sharing boundary */
26
27 #ifndef MAXASET
28 #define MAXASET 4095 /* maximum number of elements in ambient set */
29 #endif
30 OBJECT ambset[MAXASET+1]={0}; /* ambient include/exclude set */
31
32 double maxarad; /* maximum ambient radius */
33 double minarad; /* minimum ambient radius */
34
35 static AMBTREE atrunk; /* our ambient trunk node */
36
37 static FILE *ambfp = NULL; /* ambient file pointer */
38 static int nunflshed = 0; /* number of unflushed ambient values */
39
40 static double avsum = 0.; /* computed ambient value sum (log) */
41 static unsigned int navsum = 0; /* number of values in avsum */
42 static unsigned int nambvals = 0; /* total number of indirect values */
43 static unsigned int nambshare = 0; /* number of values from file */
44 static FILE *ambinp = NULL; /* auxiliary file for input */
45 static long lastpos = -1; /* last flush position */
46
47 #define AMBFLUSH (BUFSIZ/AMBVALSIZ)
48
49 #define newambval() (AMBVAL *)malloc(sizeof(AMBVAL))
50
51 #define tfunc(lwr, x, upr) (((x)-(lwr))/((upr)-(lwr)))
52
53 static void initambfile(int creat);
54 static void avsave(AMBVAL *av);
55 static AMBVAL *avstore(AMBVAL *aval);
56 static AMBTREE *newambtree(void);
57 static void freeambtree(AMBTREE *atp);
58
59 typedef void unloadtf_t(AMBVAL *);
60 static unloadtf_t avinsert;
61 static unloadtf_t avfree;
62 static void unloadatree(AMBTREE *at, unloadtf_t *f);
63
64 static void sortambvals(void);
65
66 static int plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang);
67 static double sumambient(COLOR acol, RAY *r, FVECT rn, int al,
68 AMBTREE *at, FVECT c0, double s);
69 static int makeambient(COLOR acol, RAY *r, FVECT rn, int al);
70 static int extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv,
71 FVECT uvw[3]);
72
73 #ifdef F_SETLKW
74 static void aflock(int typ);
75 #endif
76
77
78 void
79 setambres( /* set ambient resolution */
80 int ar
81 )
82 {
83 ambres = ar < 0 ? 0 : ar; /* may be done already */
84 /* set min & max radii */
85 if (ar <= 0) {
86 minarad = 0;
87 maxarad = thescene.cusize*0.2;
88 } else {
89 minarad = thescene.cusize / ar;
90 maxarad = 64.0 * minarad; /* heuristic */
91 if (maxarad > thescene.cusize*0.2)
92 maxarad = thescene.cusize*0.2;
93 }
94 if (minarad <= FTINY)
95 minarad = 10.0*FTINY;
96 if (maxarad <= minarad)
97 maxarad = 64.0 * minarad;
98 }
99
100
101 void
102 setambacc( /* set ambient accuracy */
103 double newa
104 )
105 {
106 static double olda; /* remember previous setting here */
107
108 newa *= (newa > 0);
109 if (fabs(newa - olda) >= .05*(newa + olda)) {
110 ambacc = newa;
111 if (ambacc > FTINY && nambvals > 0)
112 sortambvals(); /* rebuild tree */
113 }
114 }
115
116
117 void
118 setambient(void) /* initialize calculation */
119 {
120 int readonly = 0;
121 long flen;
122 AMBVAL amb;
123 /* make sure we're fresh */
124 ambdone();
125 /* init ambient limits */
126 setambres(ambres);
127 setambacc(ambacc);
128 if (ambfile == NULL || !ambfile[0])
129 return;
130 if (ambacc <= FTINY) {
131 sprintf(errmsg, "zero ambient accuracy so \"%s\" not opened",
132 ambfile);
133 error(WARNING, errmsg);
134 return;
135 }
136 /* open ambient file */
137 if ((ambfp = fopen(ambfile, "r+")) == NULL)
138 readonly = (ambfp = fopen(ambfile, "r")) != NULL;
139 if (ambfp != NULL) {
140 initambfile(0); /* file exists */
141 lastpos = ftell(ambfp);
142 while (readambval(&amb, ambfp))
143 avstore(&amb);
144 nambshare = nambvals; /* share loaded values */
145 if (readonly) {
146 sprintf(errmsg,
147 "loaded %u values from read-only ambient file",
148 nambvals);
149 error(WARNING, errmsg);
150 fclose(ambfp); /* close file so no writes */
151 ambfp = NULL;
152 return; /* avoid ambsync() */
153 }
154 /* align file pointer */
155 lastpos += (long)nambvals*AMBVALSIZ;
156 flen = lseek(fileno(ambfp), (off_t)0, SEEK_END);
157 if (flen != lastpos) {
158 sprintf(errmsg,
159 "ignoring last %ld values in ambient file (corrupted)",
160 (flen - lastpos)/AMBVALSIZ);
161 error(WARNING, errmsg);
162 fseek(ambfp, lastpos, SEEK_SET);
163 ftruncate(fileno(ambfp), (off_t)lastpos);
164 }
165 } else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
166 initambfile(1); /* else create new file */
167 fflush(ambfp);
168 lastpos = ftell(ambfp);
169 } else {
170 sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
171 error(SYSTEM, errmsg);
172 }
173 #ifdef F_SETLKW
174 aflock(F_UNLCK); /* release file */
175 #endif
176 }
177
178
179 void
180 ambdone(void) /* close ambient file and free memory */
181 {
182 if (ambfp != NULL) { /* close ambient file */
183 ambsync();
184 fclose(ambfp);
185 ambfp = NULL;
186 if (ambinp != NULL) {
187 fclose(ambinp);
188 ambinp = NULL;
189 }
190 lastpos = -1;
191 }
192 /* free ambient tree */
193 unloadatree(&atrunk, avfree);
194 /* reset state variables */
195 avsum = 0.;
196 navsum = 0;
197 nambvals = 0;
198 nambshare = 0;
199 }
200
201
202 void
203 ambnotify( /* record new modifier */
204 OBJECT obj
205 )
206 {
207 static int hitlimit = 0;
208 OBJREC *o;
209 char **amblp;
210
211 if (obj == OVOID) { /* starting over */
212 ambset[0] = 0;
213 hitlimit = 0;
214 return;
215 }
216 o = objptr(obj);
217 if (hitlimit || !ismodifier(o->otype))
218 return;
219 for (amblp = amblist; *amblp != NULL; amblp++)
220 if (!strcmp(o->oname, *amblp)) {
221 if (ambset[0] >= MAXASET) {
222 error(WARNING, "too many modifiers in ambient list");
223 hitlimit++;
224 return; /* should this be fatal? */
225 }
226 insertelem(ambset, obj);
227 return;
228 }
229 }
230
231
232 void
233 multambient( /* compute ambient component & multiply by coef. */
234 COLOR aval,
235 RAY *r,
236 FVECT nrm
237 )
238 {
239 static double logAvgAbsorp = 1;
240 static int rdepth = 0; /* ambient recursion */
241 COLOR acol, caustic;
242 int i, ok;
243 double d, l;
244
245 /* PMAP: Factor in ambient from photon map, if enabled and ray is
246 * ambient. Return as all ambient components accounted for, else
247 * continue. */
248 if (ambPmap(aval, r, rdepth))
249 return;
250
251 if (logAvgAbsorp > 0) /* exclude in -aw to avoid growth */
252 logAvgAbsorp = log(1.-AVGREFL);
253
254 /* PMAP: Factor in specular-diffuse ambient (caustics) from photon
255 * map, if enabled and ray is primary, else caustic is zero. Continue
256 * with RADIANCE ambient calculation */
257 copycolor(caustic, aval);
258 ambPmapCaustic(caustic, r, rdepth);
259
260 if (ambdiv <= 0) /* no ambient calculation */
261 goto dumbamb;
262 /* check number of bounces */
263 if (rdepth >= ambounce)
264 goto dumbamb;
265 /* check ambient list */
266 if (ambincl != -1 && r->ro != NULL &&
267 ambincl != inset(ambset, r->ro->omod))
268 goto dumbamb;
269
270 if (ambacc <= FTINY) { /* no ambient storage */
271 FVECT uvd[2];
272 float dgrad[2], *dgp = NULL;
273
274 if (nrm != r->ron && DOT(nrm,r->ron) < 0.9999)
275 dgp = dgrad; /* compute rotational grad. */
276 copycolor(acol, aval);
277 rdepth++;
278 ok = doambient(acol, r, r->rweight,
279 uvd, NULL, NULL, dgp, NULL);
280 rdepth--;
281 if (!ok)
282 goto dumbamb;
283 if ((ok > 0) & (dgp != NULL)) { /* apply texture */
284 FVECT v1;
285 VCROSS(v1, r->ron, nrm);
286 d = 1.0;
287 for (i = 3; i--; )
288 d += v1[i] * (dgp[0]*uvd[0][i] + dgp[1]*uvd[1][i]);
289 if (d >= 0.05)
290 scalecolor(acol, d);
291 }
292 copycolor(aval, acol);
293
294 /* PMAP: add in caustic */
295 addcolor(aval, caustic);
296 return;
297 }
298 /* interpolate ambient value */
299 setcolor(acol, 0.0, 0.0, 0.0);
300 d = sumambient(acol, r, nrm, rdepth,
301 &atrunk, thescene.cuorg, thescene.cusize);
302
303 if (d > FTINY) {
304 d = 1.0/d;
305 scalecolor(acol, d);
306 multcolor(aval, acol);
307
308 /* PMAP: add in caustic */
309 addcolor(aval, caustic);
310 return;
311 }
312
313 rdepth++; /* need to cache new value */
314 ok = makeambient(acol, r, nrm, rdepth-1);
315 rdepth--;
316
317 if (ok) {
318 multcolor(aval, acol); /* computed new value */
319
320 /* PMAP: add in caustic */
321 addcolor(aval, caustic);
322 return;
323 }
324
325 dumbamb: /* return global value */
326 if ((ambvwt <= 0) | (navsum == 0)) {
327 multcolor(aval, ambval);
328
329 /* PMAP: add in caustic */
330 addcolor(aval, caustic);
331 return;
332 }
333
334 l = bright(ambval); /* average in computations */
335 if (l > FTINY) {
336 d = (log(l)*(double)ambvwt + avsum + logAvgAbsorp*navsum) /
337 (double)(ambvwt + navsum);
338 d = exp(d) / l;
339 scalecolor(aval, d);
340 multcolor(aval, ambval); /* apply color of ambval */
341 } else {
342 d = exp( avsum/(double)navsum + logAvgAbsorp );
343 scalecolor(aval, d); /* neutral color */
344 }
345 }
346
347
348 /* Plug a potential leak where ambient cache value is occluded */
349 static int
350 plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang)
351 {
352 const double cost70sq = 0.1169778; /* cos(70deg)^2 */
353 RAY rtst;
354 FVECT vdif;
355 double normdot, ndotd, nadotd;
356 double a, b, c, t[2];
357
358 ang += 2.*PI*(ang < 0); /* check direction flags */
359 if ( !(ap->corral>>(int)(ang*(16./PI)) & 1) )
360 return(0);
361 /*
362 * Generate test ray, targeting 20 degrees above sample point plane
363 * along surface normal from cache position. This should be high
364 * enough to miss local geometry we don't really care about.
365 */
366 VSUB(vdif, ap->pos, r->rop);
367 normdot = DOT(anorm, r->ron);
368 ndotd = DOT(vdif, r->ron);
369 nadotd = DOT(vdif, anorm);
370 a = normdot*normdot - cost70sq;
371 b = 2.0*(normdot*ndotd - nadotd*cost70sq);
372 c = ndotd*ndotd - DOT(vdif,vdif)*cost70sq;
373 if (quadratic(t, a, b, c) != 2)
374 return(1); /* should rarely happen */
375 if (t[1] <= FTINY)
376 return(0); /* should fail behind test */
377 rayorigin(&rtst, SHADOW, r, NULL);
378 VSUM(rtst.rdir, vdif, anorm, t[1]); /* further dist. > plane */
379 rtst.rmax = normalize(rtst.rdir); /* short ray test */
380 while (localhit(&rtst, &thescene)) { /* check for occluder */
381 OBJREC *m = findmaterial(rtst.ro);
382 if (m != NULL && !istransp(m->otype) && !isBSDFproxy(m) &&
383 (rtst.clipset == NULL ||
384 !inset(rtst.clipset, rtst.ro->omod)))
385 return(1); /* plug light leak */
386 VCOPY(rtst.rorg, rtst.rop); /* skip invisible surface */
387 rtst.rmax -= rtst.rot;
388 rayclear(&rtst);
389 }
390 return(0); /* seems we're OK */
391 }
392
393
394 static double
395 sumambient( /* get interpolated ambient value */
396 COLOR acol,
397 RAY *r,
398 FVECT rn,
399 int al,
400 AMBTREE *at,
401 FVECT c0,
402 double s
403 )
404 { /* initial limit is 10 degrees plus ambacc radians */
405 const double minangle = 10.0 * PI/180.;
406 double maxangle = minangle + ambacc;
407 double wsum = 0.0;
408 FVECT ck0;
409 int i, j;
410 AMBVAL *av;
411
412 if (at->kid != NULL) { /* sum children first */
413 s *= 0.5;
414 for (i = 0; i < 8; i++) {
415 for (j = 0; j < 3; j++) {
416 ck0[j] = c0[j];
417 if (1<<j & i)
418 ck0[j] += s;
419 if (r->rop[j] < ck0[j] - OCTSCALE*s)
420 break;
421 if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
422 break;
423 }
424 if (j == 3)
425 wsum += sumambient(acol, r, rn, al,
426 at->kid+i, ck0, s);
427 }
428 /* good enough? */
429 if (wsum >= 0.05 && s > minarad*10.0)
430 return(wsum);
431 }
432 /* adjust maximum angle */
433 if (at->alist != NULL && (at->alist->lvl <= al) & (r->rweight < 0.6))
434 maxangle = (maxangle - PI/2.)*pow(r->rweight,0.13) + PI/2.;
435 /* sum this node */
436 for (av = at->alist; av != NULL; av = av->next) {
437 double u, v, d, delta_r2, delta_t2;
438 COLOR ct;
439 FVECT uvw[3];
440 /*
441 * Ambient level test
442 */
443 if (av->lvl > al || /* list sorted, so this works */
444 (av->lvl == al) & (av->weight < 0.9*r->rweight))
445 break;
446 /*
447 * Direction test using unperturbed normal
448 */
449 decodedir(uvw[2], av->ndir);
450 d = DOT(uvw[2], r->ron);
451 if (d <= 0.0) /* >= 90 degrees */
452 continue;
453 delta_r2 = 2.0 - 2.0*d; /* approx. radians^2 */
454 if (delta_r2 >= maxangle*maxangle)
455 continue;
456 /*
457 * Modified ray behind test
458 */
459 VSUB(ck0, r->rop, av->pos);
460 d = DOT(ck0, uvw[2]);
461 if (d < -minarad*ambacc-.001)
462 continue;
463 d /= av->rad[0];
464 delta_t2 = d*d;
465 if (delta_t2 >= ambacc*ambacc)
466 continue;
467 /*
468 * Elliptical radii test based on Hessian
469 */
470 decodedir(uvw[0], av->udir);
471 VCROSS(uvw[1], uvw[2], uvw[0]);
472 d = (u = DOT(ck0, uvw[0])) / av->rad[0];
473 delta_t2 += d*d;
474 d = (v = DOT(ck0, uvw[1])) / av->rad[1];
475 delta_t2 += d*d;
476 if (delta_t2 >= ambacc*ambacc)
477 continue;
478 /*
479 * Test for potential light leak
480 */
481 if (av->corral && plugaleak(r, av, uvw[2], atan2a(v,u)))
482 continue;
483 /*
484 * Extrapolate value and compute final weight (hat function)
485 */
486 if (!extambient(ct, av, r->rop, rn, uvw))
487 continue;
488 d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
489 tfunc(ambacc, sqrt(delta_t2), 0.0);
490 scalecolor(ct, d);
491 addcolor(acol, ct);
492 wsum += d;
493 }
494 return(wsum);
495 }
496
497
498 static int
499 makeambient( /* make a new ambient value for storage */
500 COLOR acol,
501 RAY *r,
502 FVECT rn,
503 int al
504 )
505 {
506 AMBVAL amb;
507 FVECT uvw[3];
508 int i;
509
510 amb.weight = 1.0; /* compute weight */
511 for (i = al; i-- > 0; )
512 amb.weight *= AVGREFL;
513 if (r->rweight < 0.1*amb.weight) /* heuristic override */
514 amb.weight = 1.25*r->rweight;
515 setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
516 /* compute ambient */
517 i = doambient(acol, r, amb.weight,
518 uvw, amb.rad, amb.gpos, amb.gdir, &amb.corral);
519 scalecolor(acol, 1./AVGREFL); /* undo assumed reflectance */
520 if (i <= 0 || amb.rad[0] <= FTINY) /* no Hessian or zero radius */
521 return(i);
522 /* store value */
523 VCOPY(amb.pos, r->rop);
524 amb.ndir = encodedir(r->ron);
525 amb.udir = encodedir(uvw[0]);
526 amb.lvl = al;
527 copycolor(amb.val, acol);
528 /* insert into tree */
529 avsave(&amb); /* and save to file */
530 if (rn != r->ron) { /* texture */
531 VCOPY(uvw[2], r->ron);
532 extambient(acol, &amb, r->rop, rn, uvw);
533 }
534 return(1);
535 }
536
537
538 static int
539 extambient( /* extrapolate value at pv, nv */
540 COLOR cr,
541 AMBVAL *ap,
542 FVECT pv,
543 FVECT nv,
544 FVECT uvw[3]
545 )
546 {
547 const double min_d = 0.05;
548 const double max_d = 20.;
549 static FVECT my_uvw[3];
550 FVECT v1;
551 int i;
552 double d = 1.0; /* zeroeth order */
553
554 if (uvw == NULL) { /* need local coordinates? */
555 decodedir(my_uvw[2], ap->ndir);
556 decodedir(my_uvw[0], ap->udir);
557 VCROSS(my_uvw[1], my_uvw[2], my_uvw[0]);
558 uvw = my_uvw;
559 }
560 for (i = 3; i--; ) /* gradient due to translation */
561 d += (pv[i] - ap->pos[i]) *
562 (ap->gpos[0]*uvw[0][i] + ap->gpos[1]*uvw[1][i]);
563
564 VCROSS(v1, uvw[2], nv); /* gradient due to rotation */
565 for (i = 3; i--; )
566 d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
567
568 if (d < min_d) /* clamp min/max scaling */
569 d = min_d;
570 else if (d > max_d)
571 d = max_d;
572 copycolor(cr, ap->val);
573 scalecolor(cr, d);
574 return(d > min_d);
575 }
576
577
578 static void
579 avinsert( /* insert ambient value in our tree */
580 AMBVAL *av
581 )
582 {
583 AMBTREE *at;
584 AMBVAL *ap;
585 AMBVAL avh;
586 FVECT ck0;
587 double s;
588 int branch;
589 int i;
590
591 if (av->rad[0] <= FTINY)
592 error(CONSISTENCY, "zero ambient radius in avinsert");
593 at = &atrunk;
594 VCOPY(ck0, thescene.cuorg);
595 s = thescene.cusize;
596 while (s*(OCTSCALE/2) > av->rad[1]*ambacc) {
597 if (at->kid == NULL)
598 if ((at->kid = newambtree()) == NULL)
599 error(SYSTEM, "out of memory in avinsert");
600 s *= 0.5;
601 branch = 0;
602 for (i = 0; i < 3; i++)
603 if (av->pos[i] > ck0[i] + s) {
604 ck0[i] += s;
605 branch |= 1 << i;
606 }
607 at = at->kid + branch;
608 }
609 avh.next = at->alist; /* order by increasing level */
610 for (ap = &avh; ap->next != NULL; ap = ap->next)
611 if ( ap->next->lvl > av->lvl ||
612 (ap->next->lvl == av->lvl) &
613 (ap->next->weight <= av->weight) )
614 break;
615 av->next = ap->next;
616 ap->next = (AMBVAL*)av;
617 at->alist = avh.next;
618 }
619
620
621 static void
622 initambfile( /* initialize ambient file */
623 int cre8
624 )
625 {
626 extern char *progname, *octname;
627 static char *mybuf = NULL;
628
629 #ifdef F_SETLKW
630 aflock(cre8 ? F_WRLCK : F_RDLCK);
631 #endif
632 SET_FILE_BINARY(ambfp);
633 if (mybuf == NULL)
634 mybuf = (char *)bmalloc(BUFSIZ+8);
635 setbuf(ambfp, mybuf);
636 if (cre8) { /* new file */
637 newheader("RADIANCE", ambfp);
638 fprintf(ambfp, "%s -av %g %g %g -aw %d -ab %d -aa %g ",
639 progname, colval(ambval,RED),
640 colval(ambval,GRN), colval(ambval,BLU),
641 ambvwt, ambounce, ambacc);
642 fprintf(ambfp, "-ad %d -as %d -ar %d ",
643 ambdiv, ambssamp, ambres);
644 if (octname != NULL)
645 fputs(octname, ambfp);
646 fputc('\n', ambfp);
647 fprintf(ambfp, "SOFTWARE= %s\n", VersionID);
648 fputnow(ambfp);
649 fputformat(AMBFMT, ambfp);
650 fputc('\n', ambfp);
651 putambmagic(ambfp);
652 } else if (checkheader(ambfp, AMBFMT, NULL) < 0 || !hasambmagic(ambfp))
653 error(USER, "bad ambient file");
654 }
655
656
657 static void
658 avsave( /* insert and save an ambient value */
659 AMBVAL *av
660 )
661 {
662 avstore(av);
663 if (ambfp == NULL)
664 return;
665 if (writambval(av, ambfp) < 0)
666 goto writerr;
667 if (++nunflshed >= AMBFLUSH)
668 if (ambsync() == EOF)
669 goto writerr;
670 return;
671 writerr:
672 error(SYSTEM, "error writing to ambient file");
673 }
674
675
676 static AMBVAL *
677 avstore( /* allocate memory and save aval */
678 AMBVAL *aval
679 )
680 {
681 AMBVAL *av;
682 double d;
683
684 if ((av = newambval()) == NULL)
685 error(SYSTEM, "out of memory in avstore");
686 *av = *aval;
687 av->next = NULL;
688 nambvals++;
689 d = bright(av->val);
690 if (d > FTINY) { /* add to log sum for averaging */
691 avsum += log(d);
692 navsum++;
693 }
694 avinsert(av); /* insert in our cache tree */
695 return(av);
696 }
697
698
699 #define ATALLOCSZ 512 /* #/8 trees to allocate at once */
700
701 static AMBTREE *atfreelist = NULL; /* free ambient tree structures */
702
703
704 static AMBTREE *
705 newambtree(void) /* allocate 8 ambient tree structs */
706 {
707 AMBTREE *atp, *upperlim;
708
709 if (atfreelist == NULL) { /* get more nodes */
710 atfreelist = (AMBTREE *)malloc(ATALLOCSZ*8*sizeof(AMBTREE));
711 if (atfreelist == NULL)
712 return(NULL);
713 /* link new free list */
714 upperlim = atfreelist + 8*(ATALLOCSZ-1);
715 for (atp = atfreelist; atp < upperlim; atp += 8)
716 atp->kid = atp + 8;
717 atp->kid = NULL;
718 }
719 atp = atfreelist;
720 atfreelist = atp->kid;
721 memset(atp, 0, 8*sizeof(AMBTREE));
722 return(atp);
723 }
724
725
726 static void
727 freeambtree( /* free 8 ambient tree structs */
728 AMBTREE *atp
729 )
730 {
731 atp->kid = atfreelist;
732 atfreelist = atp;
733 }
734
735
736 static void
737 unloadatree( /* unload an ambient value tree */
738 AMBTREE *at,
739 unloadtf_t *f
740 )
741 {
742 AMBVAL *av;
743 int i;
744 /* transfer values at this node */
745 for (av = at->alist; av != NULL; av = at->alist) {
746 at->alist = av->next;
747 av->next = NULL;
748 (*f)(av);
749 }
750 if (at->kid == NULL)
751 return;
752 for (i = 0; i < 8; i++) /* transfer and free children */
753 unloadatree(at->kid+i, f);
754 freeambtree(at->kid);
755 at->kid = NULL;
756 }
757
758
759 static void
760 avfree(AMBVAL *av)
761 {
762 free(av);
763 }
764
765
766 static void
767 sortambvals(void) /* resort ambient values */
768 {
769 AMBTREE oldatrunk = atrunk;
770
771 atrunk.alist = NULL;
772 atrunk.kid = NULL;
773 unloadatree(&oldatrunk, avinsert);
774 }
775
776
777 #ifdef F_SETLKW
778
779 static void
780 aflock( /* lock/unlock ambient file */
781 int typ
782 )
783 {
784 static struct flock fls; /* static so initialized to zeroes */
785
786 if (typ == fls.l_type) /* already called? */
787 return;
788
789 fls.l_type = typ;
790 do
791 if (fcntl(fileno(ambfp), F_SETLKW, &fls) != -1)
792 return;
793 while (errno == EINTR);
794
795 error(SYSTEM, "cannot (un)lock ambient file");
796 }
797
798
799 int
800 ambsync(void) /* synchronize ambient file */
801 {
802 long flen;
803 AMBVAL avs;
804 int n;
805
806 if (ambfp == NULL) /* no ambient file? */
807 return(0);
808 /* gain appropriate access */
809 aflock(nunflshed ? F_WRLCK : F_RDLCK);
810 /* see if file has grown */
811 if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
812 goto seekerr;
813 if ((n = flen - lastpos) > 0) { /* file has grown */
814 if (ambinp == NULL) { /* get new file pointer */
815 ambinp = fopen(ambfile, "rb");
816 if (ambinp == NULL)
817 error(SYSTEM, "fopen failed in ambsync");
818 }
819 if (fseek(ambinp, lastpos, SEEK_SET) < 0)
820 goto seekerr;
821 while (n >= AMBVALSIZ) { /* load contributed values */
822 if (!readambval(&avs, ambinp)) {
823 sprintf(errmsg,
824 "ambient file \"%s\" corrupted near character %ld",
825 ambfile, flen - n);
826 error(WARNING, errmsg);
827 break;
828 }
829 avstore(&avs);
830 n -= AMBVALSIZ;
831 }
832 lastpos = flen - n; /* check alignment */
833 if (n && lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
834 goto seekerr;
835 }
836 n = fflush(ambfp); /* calls write() at last */
837 lastpos += (long)nunflshed*AMBVALSIZ;
838 aflock(F_UNLCK); /* release file */
839 nunflshed = 0;
840 return(n);
841 seekerr:
842 error(SYSTEM, "seek failed in ambsync");
843 return(EOF); /* pro forma return */
844 }
845
846 #else /* ! F_SETLKW */
847
848 int
849 ambsync(void) /* flush ambient file */
850 {
851 if (ambfp == NULL)
852 return(0);
853 nunflshed = 0;
854 return(fflush(ambfp));
855 }
856
857 #endif /* ! F_SETLKW */