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root/radiance/ray/src/hd/holofile.c
Revision: 3.28
Committed: Mon Nov 9 17:10:53 1998 UTC (25 years, 5 months ago) by gwlarson
Content type: text/plain
Branch: MAIN
Changes since 3.27: +65 -25 lines
Log Message:
changed section directory code to write in segments

File Contents

# Content
1 /* Copyright (c) 1998 Silicon Graphics, Inc. */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ SGI";
5 #endif
6
7 /*
8 * Routines for managing holodeck files
9 *
10 * 9/30/97 GWLarson
11 */
12
13 #include "holo.h"
14
15 #ifndef CACHESIZE
16 #define CACHESIZE 16 /* default cache size (Mbytes, 0==inf) */
17 #endif
18 #ifndef FREEBEAMS
19 #define FREEBEAMS 1500 /* maximum beams to free at a time */
20 #endif
21 #ifndef PCTFREE
22 #define PCTFREE 15 /* maximum fraction to free (%) */
23 #endif
24 #ifndef MAXFRAG
25 #define MAXFRAG 32767 /* maximum fragments/file to track (0==inf) */
26 #endif
27
28 #ifndef BSD
29 #define write writebuf /* safe i/o routines */
30 #define read readbuf
31 #endif
32
33 #define FRAGBLK 256 /* number of fragments to allocate at a time */
34
35 unsigned hdcachesize = CACHESIZE*1024*1024; /* target cache size */
36 unsigned long hdclock; /* clock value */
37
38 HOLO *hdlist[HDMAX+1]; /* holodeck pointers (NULL term.) */
39
40 static struct fraglist {
41 short nlinks; /* number of holodeck sections using us */
42 short writerr; /* write error encountered */
43 int nfrags; /* number of known fragments */
44 BEAMI *fi; /* fragments, descending file position */
45 long flen; /* last known file length */
46 } *hdfragl; /* fragment lists, indexed by file descriptor */
47
48 static int nhdfragls; /* size of hdfragl array */
49
50
51 char *
52 hdrealloc(ptr, siz, rout) /* (re)allocate memory, retry then error */
53 char *ptr;
54 unsigned siz;
55 char *rout;
56 {
57 register char *newp;
58 /* call malloc/realloc */
59 if (ptr == NULL) newp = (char *)malloc(siz);
60 else newp = (char *)realloc(ptr, siz);
61 /* check success */
62 if (newp == NULL && rout != NULL) {
63 hdfreecache(25, NULL); /* free some memory */
64 errno = 0; /* retry */
65 newp = hdrealloc(ptr, siz, NULL);
66 if (newp == NULL) { /* give up and report error */
67 sprintf(errmsg, "out of memory in %s", rout);
68 error(SYSTEM, errmsg);
69 }
70 }
71 return(newp);
72 }
73
74
75 hdattach(fd) /* start tracking file fragments for some section */
76 register int fd;
77 {
78 if (fd >= nhdfragls) {
79 hdfragl = (struct fraglist *)hdrealloc((char *)hdfragl,
80 (fd+1)*sizeof(struct fraglist), "hdattach");
81 bzero((char *)(hdfragl+nhdfragls),
82 (fd+1-nhdfragls)*sizeof(struct fraglist));
83 nhdfragls = fd+1;
84 }
85 hdfragl[fd].nlinks++;
86 hdfragl[fd].flen = lseek(fd, 0L, 2); /* get file length */
87 }
88
89
90 /* Do we need a routine to locate file fragments given known occupants? */
91
92
93 hdrelease(fd) /* stop tracking file fragments for some section */
94 register int fd;
95 {
96 if (fd < 0 | fd >= nhdfragls || !hdfragl[fd].nlinks)
97 return;
98 if (!--hdfragl[fd].nlinks && hdfragl[fd].nfrags) {
99 free((char *)hdfragl[fd].fi);
100 hdfragl[fd].fi = NULL;
101 hdfragl[fd].nfrags = 0;
102 }
103 }
104
105
106 HOLO *
107 hdinit(fd, hproto) /* initialize a holodeck section in a file */
108 int fd; /* corresponding file descriptor */
109 HDGRID *hproto; /* holodeck section grid */
110 {
111 long rtrunc;
112 long fpos;
113 register HOLO *hp;
114 register int n;
115 /* prepare for system errors */
116 errno = 0;
117 if ((fpos = lseek(fd, 0L, 1)) < 0)
118 error(SYSTEM, "cannot determine holodeck file position");
119 if (hproto == NULL) { /* assume we're loading it */
120 HDGRID hpr;
121 /* load header */
122 if (read(fd, (char *)&hpr, sizeof(HDGRID)) != sizeof(HDGRID))
123 error(SYSTEM, "cannot load holodeck header");
124 /* allocate grid */
125 if ((hp = hdalloc(&hpr)) == NULL)
126 goto memerr;
127 /* load beam directory */
128 n = nbeams(hp)*sizeof(BEAMI);
129 if (read(fd, (char *)(hp->bi+1), n) != n)
130 error(SYSTEM, "failure loading holodeck directory");
131 /* check that it's clean */
132 for (n = nbeams(hp); n > 0; n--)
133 if (hp->bi[n].fo < 0) {
134 hp->bi[n].fo = 0;
135 error(WARNING, "dirty holodeck section");
136 break;
137 }
138 } else { /* assume we're creating it */
139 if ((hp = hdalloc(hproto)) == NULL)
140 goto memerr;
141 /* write header and skeleton */
142 n = nbeams(hp)*sizeof(BEAMI);
143 if (write(fd, (char *)hproto, sizeof(HDGRID)) !=
144 sizeof(HDGRID) ||
145 write(fd, (char *)(hp->bi+1), n) != n)
146 error(SYSTEM, "cannot write header to holodeck file");
147 }
148 hp->fd = fd;
149 hp->dirty = 0;
150 biglob(hp)->fo = fpos + sizeof(HDGRID);
151 /* start tracking fragments */
152 hdattach(fd);
153 /* check rays on disk */
154 fpos = hdfilen(fd);
155 biglob(hp)->nrd = rtrunc = 0;
156 for (n = hproto == NULL ? nbeams(hp) : 0; n > 0; n--)
157 if (hp->bi[n].nrd)
158 if (hp->bi[n].fo+hp->bi[n].nrd*sizeof(RAYVAL) > fpos) {
159 rtrunc += hp->bi[n].nrd;
160 hp->bi[n].nrd = 0;
161 } else
162 biglob(hp)->nrd += hp->bi[n].nrd;
163 if (rtrunc) {
164 sprintf(errmsg, "truncated section, %ld rays lost (%.1f%%)",
165 rtrunc, 100.*rtrunc/(rtrunc+biglob(hp)->nrd));
166 error(WARNING, errmsg);
167 }
168 /* add to holodeck list */
169 for (n = 0; n < HDMAX; n++)
170 if (hdlist[n] == NULL) {
171 hdlist[n] = hp;
172 break;
173 }
174 /* all done */
175 return(hp);
176 memerr:
177 error(SYSTEM, "cannot allocate holodeck grid");
178 }
179
180
181 markdirty(hp, i) /* mark holodeck directory position dirty */
182 register HOLO *hp;
183 int i;
184 {
185 static BEAMI smudge = {0, -1};
186 int mindist, minpos;
187 register int j;
188
189 if (!hp->dirty++) { /* write smudge first time */
190 if (lseek(hp->fd, biglob(hp)->fo+(i-1)*sizeof(BEAMI), 0) < 0
191 || write(hp->fd, (char *)&smudge,
192 sizeof(BEAMI)) != sizeof(BEAMI))
193 error(SYSTEM, "seek/write error in markdirty");
194 hp->dirseg[0].s = i;
195 hp->dirseg[0].n = 1;
196 return;
197 }
198 /* insert into segment list */
199 for (j = hp->dirty; j--; ) {
200 if (!j || hp->dirseg[j-1].s < i) {
201 hp->dirseg[j].s = i;
202 hp->dirseg[j].n = 1;
203 break;
204 }
205 copystruct(hp->dirseg+j, hp->dirseg+(j-1));
206 }
207 mindist = nbeams(hp); /* find closest neighbors */
208 for (j = hp->dirty; --j; )
209 if (hp->dirseg[j].s - (hp->dirseg[j-1].s + hp->dirseg[j-1].n)
210 < mindist) {
211 mindist = hp->dirseg[j].s -
212 (hp->dirseg[j-1].s + hp->dirseg[j-1].n);
213 minpos = j;
214 }
215 if (hp->dirty > MAXDIRSE || mindist <= BUFSIZ/sizeof(BEAMI)) {
216 j = minpos - 1; /* coalesce neighbors */
217 if (hp->dirseg[j].s + hp->dirseg[j].n <
218 hp->dirseg[minpos].s + hp->dirseg[minpos].n) {
219 hp->dirseg[j].n = hp->dirseg[minpos].s +
220 hp->dirseg[minpos].n - hp->dirseg[j].s;
221 }
222 hp->dirty--; /* close the gap */
223 for (j = minpos; j < hp->dirty; j++)
224 copystruct(hp->dirseg+j, hp->dirseg+(j+1));
225 }
226 }
227
228
229 int
230 hdsync(hp, all) /* update beams and directory on disk */
231 register HOLO *hp;
232 int all;
233 {
234 register int j, n;
235
236 if (hp == NULL) { /* do all holodecks */
237 n = 0;
238 for (j = 0; hdlist[j] != NULL; j++)
239 n += hdsync(hdlist[j], all);
240 return(n);
241 }
242 /* sync the beams */
243 for (j = (all ? nbeams(hp) : 0); j > 0; j--)
244 if (hp->bl[j] != NULL)
245 hdsyncbeam(hp, j);
246 if (!hp->dirty) /* directory clean? */
247 return(0);
248 errno = 0; /* write dirty segments */
249 for (j = 0; j < hp->dirty; j++) {
250 if (lseek(hp->fd, biglob(hp)->fo +
251 (hp->dirseg[j].s-1)*sizeof(BEAMI), 0) < 0)
252 error(SYSTEM, "cannot seek on holodeck file");
253 n = hp->dirseg[j].n * sizeof(BEAMI);
254 if (write(hp->fd, (char *)(hp->bi+hp->dirseg[j].s), n) != n)
255 error(SYSTEM, "cannot update section directory");
256 }
257 hp->dirty = 0; /* all clean */
258 return(1);
259 }
260
261
262 unsigned
263 hdmemuse(all) /* return memory usage (in bytes) */
264 int all; /* include overhead (painful) */
265 {
266 long total = 0;
267 register int i, j;
268
269 for (j = 0; hdlist[j] != NULL; j++) {
270 total += blglob(hdlist[j])->nrm * sizeof(RAYVAL);
271 if (all) {
272 total += sizeof(HOLO) + sizeof(BEAM *) +
273 nbeams(hdlist[j]) *
274 (sizeof(BEAM *)+sizeof(BEAMI));
275 for (i = nbeams(hdlist[j]); i > 0; i--)
276 if (hdlist[j]->bl[i] != NULL)
277 total += sizeof(BEAM);
278 }
279 }
280 if (all)
281 for (j = 0; j < nhdfragls; j++) {
282 total += sizeof(struct fraglist);
283 if (hdfragl[j].nfrags)
284 total += FRAGBLK*sizeof(BEAMI) *
285 ((hdfragl[j].nfrags-1)/FRAGBLK + 1) ;
286 }
287 return(total);
288 }
289
290
291 long
292 hdfilen(fd) /* return file length for fd */
293 int fd;
294 {
295 long fpos, flen;
296
297 if (fd < 0)
298 return(-1);
299 if (fd >= nhdfragls || !hdfragl[fd].nlinks) {
300 if ((fpos = lseek(fd, 0L, 1)) < 0)
301 return(-1);
302 flen = lseek(fd, 0L, 2);
303 lseek(fd, fpos, 0);
304 return(flen);
305 }
306 return(hdfragl[fd].flen);
307 }
308
309
310 long
311 hdfiluse(fd, all) /* compute file usage (in bytes) */
312 int fd; /* open file descriptor to check */
313 int all; /* include overhead and unflushed data */
314 {
315 long total = 0;
316 register int i, j;
317
318 for (j = 0; hdlist[j] != NULL; j++) {
319 if (hdlist[j]->fd != fd)
320 continue;
321 total += biglob(hdlist[j])->nrd * sizeof(RAYVAL);
322 if (all) {
323 for (i = nbeams(hdlist[j]); i > 0; i--)
324 if (hdlist[j]->bl[i] != NULL)
325 total += sizeof(RAYVAL) *
326 (hdlist[j]->bl[i]->nrm -
327 hdlist[j]->bi[i].nrd);
328 total += sizeof(HDGRID) +
329 nbeams(hdlist[j])*sizeof(BEAMI);
330 }
331 }
332 return(total); /* does not include fragments */
333 }
334
335
336 RAYVAL *
337 hdnewrays(hp, i, nr) /* allocate space for add'l rays and return pointer */
338 register HOLO *hp;
339 register int i;
340 int nr; /* number of new rays desired */
341 {
342 RAYVAL *p;
343 int n;
344
345 if (nr <= 0)
346 return(NULL);
347 if (i < 1 | i > nbeams(hp))
348 error(CONSISTENCY, "bad beam index given to hdnewrays");
349 if (hp->bl[i] != NULL)
350 hp->bl[i]->tick = hdclock; /* preempt swap */
351 if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
352 hdfreecache(PCTFREE, NULL); /* free some space */
353 if (hp->bl[i] == NULL) { /* allocate (and load) */
354 n = hp->bi[i].nrd + nr;
355 hp->bl[i] = (BEAM *)hdrealloc(NULL, hdbsiz(n), "hdnewrays");
356 blglob(hp)->nrm += n;
357 if (n = hp->bl[i]->nrm = hp->bi[i].nrd) {
358 errno = 0;
359 if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
360 error(SYSTEM, "seek error on holodeck file");
361 n *= sizeof(RAYVAL);
362 if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
363 error(SYSTEM,
364 "error reading beam from holodeck file");
365 }
366 } else { /* just grow in memory */
367 hp->bl[i] = (BEAM *)hdrealloc((char *)hp->bl[i],
368 hdbsiz(hp->bl[i]->nrm + nr), "hdnewrays");
369 blglob(hp)->nrm += nr;
370 }
371 p = hdbray(hp->bl[i]) + hp->bl[i]->nrm;
372 hp->bl[i]->nrm += nr; /* update in-core structure */
373 bzero((char *)p, nr*sizeof(RAYVAL));
374 blglob(hp)->tick = hp->bl[i]->tick = hdclock++; /* update LRU clock */
375 return(p); /* point to new rays */
376 }
377
378
379 BEAM *
380 hdgetbeam(hp, i) /* get beam (from file if necessary) */
381 register HOLO *hp;
382 register int i;
383 {
384 register int n;
385
386 if (i < 1 | i > nbeams(hp))
387 error(CONSISTENCY, "bad beam index given to hdgetbeam");
388 if (hp->bl[i] == NULL) { /* load from disk */
389 if (!(n = hp->bi[i].nrd))
390 return(NULL);
391 if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
392 hdfreecache(PCTFREE, NULL); /* get free space */
393 hp->bl[i] = (BEAM *)hdrealloc(NULL, hdbsiz(n), "hdgetbeam");
394 blglob(hp)->nrm += hp->bl[i]->nrm = n;
395 errno = 0;
396 if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
397 error(SYSTEM, "seek error on holodeck file");
398 n *= sizeof(RAYVAL);
399 if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
400 error(SYSTEM, "error reading beam from holodeck file");
401 }
402 blglob(hp)->tick = hp->bl[i]->tick = hdclock++; /* update LRU clock */
403 return(hp->bl[i]);
404 }
405
406
407 int
408 hdfilord(hb1, hb2) /* order beams for quick loading */
409 register HDBEAMI *hb1, *hb2;
410 {
411 register long c;
412 /* residents go first */
413 if (hb2->h->bl[hb2->b] != NULL)
414 return(hb1->h->bl[hb1->b] == NULL);
415 if (hb1->h->bl[hb1->b] != NULL)
416 return(-1);
417 /* otherwise sort by file descriptor */
418 if ((c = hb1->h->fd - hb2->h->fd))
419 return(c);
420 /* then by position in file */
421 c = hb1->h->bi[hb1->b].fo - hb2->h->bi[hb2->b].fo;
422 return(c > 0 ? 1 : c < 0 ? -1 : 0);
423 }
424
425
426 hdloadbeams(hb, n, bf) /* load a list of beams in optimal order */
427 register HDBEAMI *hb; /* list gets sorted by hdfilord() */
428 int n; /* list length */
429 int (*bf)(); /* callback function (optional) */
430 {
431 unsigned origcachesize, memuse;
432 int bytesloaded, needbytes, bytes2free;
433 register BEAM *bp;
434 register int i;
435 /* precheck consistency */
436 if (n <= 0) return;
437 for (i = n; i--; )
438 if (hb[i].h == NULL || hb[i].b < 1 | hb[i].b > nbeams(hb[i].h))
439 error(CONSISTENCY, "bad beam in hdloadbeams");
440 /* sort list for optimal access */
441 qsort((char *)hb, n, sizeof(HDBEAMI), hdfilord);
442 bytesloaded = 0; /* run through loaded beams */
443 for ( ; n && (bp = hb->h->bl[hb->b]) != NULL; n--, hb++) {
444 bp->tick = hdclock; /* preempt swap */
445 bytesloaded += bp->nrm;
446 if (bf != NULL)
447 (*bf)(bp, hb);
448 }
449 bytesloaded *= sizeof(RAYVAL);
450 if ((origcachesize = hdcachesize) > 0) {
451 needbytes = 0; /* figure out memory needs */
452 for (i = n; i--; )
453 needbytes += hb[i].h->bi[hb[i].b].nrd;
454 needbytes *= sizeof(RAYVAL);
455 do { /* free enough memory */
456 memuse = hdmemuse(0);
457 bytes2free = needbytes - (int)(hdcachesize-memuse);
458 if (bytes2free > (int)(memuse - bytesloaded))
459 bytes2free = memuse - bytesloaded;
460 } while (bytes2free > 0 &&
461 hdfreecache(100*bytes2free/memuse, NULL) < 0);
462 hdcachesize = 0; /* load beams w/o swap */
463 }
464 for (i = 0; i < n; i++)
465 if ((bp = hdgetbeam(hb[i].h, hb[i].b)) != NULL && bf != NULL)
466 (*bf)(bp, hb+i);
467 hdcachesize = origcachesize; /* resume dynamic swapping */
468 }
469
470
471 hdfreefrag(fd, bi) /* free a file fragment */
472 int fd;
473 register BEAMI *bi;
474 {
475 register struct fraglist *f;
476 register int j, k;
477
478 if (bi->nrd == 0)
479 return;
480 #ifdef DEBUG
481 if (fd < 0 | fd >= nhdfragls || !hdfragl[fd].nlinks)
482 error(CONSISTENCY, "bad file descriptor in hdfreefrag");
483 #endif
484 f = &hdfragl[fd];
485 if (f->nfrags % FRAGBLK == 0) { /* delete empty remnants */
486 for (j = k = 0; k < f->nfrags; j++, k++) {
487 while (f->fi[k].nrd == 0)
488 if (++k >= f->nfrags)
489 goto endloop;
490 if (k > j)
491 copystruct(f->fi+j, f->fi+k);
492 }
493 endloop:
494 f->nfrags = j;
495 }
496 j = f->nfrags++; /* allocate a slot in free list */
497 #if MAXFRAG
498 if (j >= MAXFRAG-1)
499 f->nfrags--;
500 #endif
501 if (j % FRAGBLK == 0) { /* more free list space */
502 register BEAMI *newp;
503 if (f->fi == NULL)
504 newp = (BEAMI *)malloc((j+FRAGBLK)*sizeof(BEAMI));
505 else
506 newp = (BEAMI *)realloc((char *)f->fi,
507 (j+FRAGBLK)*sizeof(BEAMI));
508 if (newp == NULL) {
509 f->nfrags--; /* graceful failure */
510 return;
511 }
512 f->fi = newp;
513 }
514 for ( ; ; j--) { /* insert in descending list */
515 if (!j || bi->fo < f->fi[j-1].fo) {
516 f->fi[j].fo = bi->fo;
517 f->fi[j].nrd = bi->nrd;
518 break;
519 }
520 copystruct(f->fi+j, f->fi+(j-1));
521 }
522 /* coalesce adjacent fragments */
523 /* successors never empty */
524 if (j && f->fi[j-1].fo == f->fi[j].fo + f->fi[j].nrd*sizeof(RAYVAL)) {
525 f->fi[j].nrd += f->fi[j-1].nrd;
526 f->fi[j-1].nrd = 0;
527 }
528 for (k = j+1; k < f->nfrags; k++) /* get non-empty predecessor */
529 if (f->fi[k].nrd) {
530 if (f->fi[j].fo == f->fi[k].fo +
531 f->fi[k].nrd*sizeof(RAYVAL)) {
532 f->fi[k].nrd += f->fi[j].nrd;
533 f->fi[j].nrd = 0;
534 }
535 break;
536 }
537 }
538
539
540 long
541 hdallocfrag(fd, nrays) /* allocate a file fragment */
542 int fd;
543 unsigned int4 nrays;
544 {
545 register struct fraglist *f;
546 register int j, k;
547 long nfo;
548
549 if (nrays == 0)
550 return(-1L);
551 #ifdef DEBUG
552 if (fd < 0 | fd >= nhdfragls || !hdfragl[fd].nlinks)
553 error(CONSISTENCY, "bad file descriptor in hdallocfrag");
554 #endif
555 f = &hdfragl[fd];
556 k = -1; /* find closest-sized fragment */
557 for (j = f->nfrags; j-- > 0; )
558 if (f->fi[j].nrd >= nrays &&
559 (k < 0 || f->fi[j].nrd < f->fi[k].nrd))
560 if (f->fi[k=j].nrd == nrays)
561 break;
562 if (k < 0) { /* no fragment -- extend file */
563 nfo = f->flen;
564 f->flen += nrays*sizeof(RAYVAL);
565 } else { /* else use fragment */
566 nfo = f->fi[k].fo;
567 f->fi[k].fo += nrays*sizeof(RAYVAL);
568 f->fi[k].nrd -= nrays;
569 }
570 return(nfo);
571 }
572
573
574 int
575 hdsyncbeam(hp, i) /* sync beam in memory with beam on disk */
576 register HOLO *hp;
577 register int i;
578 {
579 unsigned int4 nrays;
580 unsigned int n;
581 long nfo;
582 /* check file status */
583 if (hdfragl[hp->fd].writerr)
584 return(-1);
585 #ifdef DEBUG
586 if (i < 1 | i > nbeams(hp))
587 error(CONSISTENCY, "bad beam index in hdsyncbeam");
588 #endif
589 /* is current fragment OK? */
590 if (hp->bl[i] == NULL || (nrays = hp->bl[i]->nrm) == hp->bi[i].nrd)
591 return(0);
592 if (hp->bi[i].nrd) /* relinquish old fragment */
593 hdfreefrag(hp->fd, &hp->bi[i]);
594 if (nrays) { /* get and write new fragment */
595 nfo = hdallocfrag(hp->fd, nrays);
596 errno = 0;
597 if (lseek(hp->fd, nfo, 0) < 0)
598 error(SYSTEM, "cannot seek on holodeck file");
599 n = hp->bl[i]->nrm * sizeof(RAYVAL);
600 if (write(hp->fd, (char *)hdbray(hp->bl[i]), n) != n) {
601 hdfragl[hp->fd].writerr++;
602 hdsync(NULL, 0); /* sync directories */
603 error(SYSTEM, "write error in hdsyncbeam");
604 }
605 hp->bi[i].fo = nfo;
606 } else
607 hp->bi[i].fo = 0L;
608 biglob(hp)->nrd += nrays - hp->bi[i].nrd;
609 hp->bi[i].nrd = nrays;
610 markdirty(hp, i); /* section directory now out of date */
611 return(1);
612 }
613
614
615 int
616 hdfreebeam(hp, i) /* free beam, writing if dirty */
617 register HOLO *hp;
618 register int i;
619 {
620 int nchanged;
621
622 if (hp == NULL) { /* clear all holodecks */
623 nchanged = 0;
624 for (i = 0; hdlist[i] != NULL; i++)
625 nchanged += hdfreebeam(hdlist[i], 0);
626 return(nchanged);
627 }
628 if (hdfragl[hp->fd].writerr) /* check for file error */
629 return(0);
630 if (i == 0) { /* clear entire holodeck */
631 nchanged = 0;
632 for (i = nbeams(hp); i > 0; i--)
633 if (hp->bl[i] != NULL)
634 nchanged += hdfreebeam(hp, i);
635 return(nchanged);
636 }
637 #ifdef DEBUG
638 if (i < 1 | i > nbeams(hp))
639 error(CONSISTENCY, "bad beam index to hdfreebeam");
640 #endif
641 if (hp->bl[i] == NULL)
642 return(0);
643 /* check for additions */
644 nchanged = hp->bl[i]->nrm - hp->bi[i].nrd;
645 if (nchanged)
646 hdsyncbeam(hp, i); /* write new fragment */
647 blglob(hp)->nrm -= hp->bl[i]->nrm;
648 free((char *)hp->bl[i]); /* free memory */
649 hp->bl[i] = NULL;
650 return(nchanged);
651 }
652
653
654 int
655 hdkillbeam(hp, i) /* delete beam from holodeck */
656 register HOLO *hp;
657 register int i;
658 {
659 static BEAM emptybeam;
660 int nchanged;
661
662 if (hp == NULL) { /* clobber all holodecks */
663 nchanged = 0;
664 for (i = 0; hdlist[i] != NULL; i++)
665 nchanged += hdkillbeam(hdlist[i], 0);
666 return(nchanged);
667 }
668 if (i == 0) { /* clobber entire holodeck */
669 nchanged = 0;
670 for (i = nbeams(hp); i > 0; i--)
671 if (hp->bi[i].nrd > 0 || hp->bl[i] != NULL)
672 nchanged += hdkillbeam(hp, i);
673 #ifdef DEBUG
674 if (biglob(hp)->nrd != 0 | blglob(hp)->nrm != 0)
675 error(CONSISTENCY, "bad beam count in hdkillbeam");
676 #endif
677 return(nchanged);
678 }
679 #ifdef DEBUG
680 if (i < 1 | i > nbeams(hp))
681 error(CONSISTENCY, "bad beam index to hdkillbeam");
682 #endif
683 if (hp->bl[i] != NULL) { /* free memory */
684 blglob(hp)->nrm -= nchanged = hp->bl[i]->nrm;
685 free((char *)hp->bl[i]);
686 } else
687 nchanged = hp->bi[i].nrd;
688 if (hp->bi[i].nrd) { /* free file fragment */
689 hp->bl[i] = &emptybeam;
690 hdsyncbeam(hp, i);
691 }
692 hp->bl[i] = NULL;
693 return(nchanged);
694 }
695
696
697 int
698 hdlrulist(hb, nents, n, hp) /* add beams from holodeck to LRU list */
699 register HDBEAMI *hb; /* beam list */
700 int nents; /* current list length */
701 int n; /* maximum list length */
702 register HOLO *hp; /* section we're adding from */
703 {
704 register int i, j;
705 /* insert each beam from hp */
706 for (i = 1; i <= nbeams(hp); i++) {
707 if (hp->bl[i] == NULL) /* check if loaded */
708 continue;
709 #if 0
710 if (hp->bl[i]->tick == hdclock) /* preempt swap? */
711 continue;
712 #endif
713 if ((j = ++nents) >= n) /* grow list if we can */
714 nents--;
715 for ( ; ; ) { /* bubble into place */
716 if (!--j || hp->bl[i]->tick >=
717 hb[j-1].h->bl[hb[j-1].b]->tick) {
718 hb[j].h = hp;
719 hb[j].b = i;
720 break;
721 }
722 copystruct(hb+j, hb+(j-1));
723 }
724 }
725 return(nents); /* return new list length */
726 }
727
728
729 int
730 hdfreecache(pct, honly) /* free up cache space, writing changes */
731 int pct; /* maximum percentage to free */
732 register HOLO *honly; /* NULL means check all */
733 {
734 HDBEAMI hb[FREEBEAMS];
735 int freetarget;
736 int n;
737 register int i;
738 #ifdef DEBUG
739 unsigned membefore;
740
741 membefore = hdmemuse(0);
742 #endif
743 /* compute free target */
744 freetarget = (honly != NULL) ? blglob(honly)->nrm :
745 hdmemuse(0)/sizeof(RAYVAL) ;
746 freetarget = freetarget*pct/100;
747 if (freetarget <= 0)
748 return(0);
749 /* find least recently used */
750 n = 0;
751 if (honly != NULL)
752 n = hdlrulist(hb, n, FREEBEAMS, honly);
753 else
754 for (i = 0; hdlist[i] != NULL; i++)
755 n = hdlrulist(hb, n, FREEBEAMS, hdlist[i]);
756 /* free LRU beams */
757 for (i = 0; i < n; i++) {
758 hdfreebeam(hb[i].h, hb[i].b);
759 if ((freetarget -= hb[i].h->bi[hb[i].b].nrd) <= 0)
760 break;
761 }
762 hdsync(honly, 0); /* synchronize directories as necessary */
763 #ifdef DEBUG
764 sprintf(errmsg,
765 "%dK before, %dK after hdfreecache (%dK total), %d rays short\n",
766 membefore>>10, hdmemuse(0)>>10, hdmemuse(1)>>10, freetarget);
767 wputs(errmsg);
768 #endif
769 return(-freetarget); /* return how far past goal we went */
770 }
771
772
773 hddone(hp) /* clean up holodeck section and free */
774 register HOLO *hp; /* NULL means clean up all */
775 {
776 register int i;
777
778 if (hp == NULL) { /* NULL means clean up everything */
779 while (hdlist[0] != NULL)
780 hddone(hdlist[0]);
781 free((char *)hdfragl);
782 hdfragl = NULL; nhdfragls = 0;
783 return;
784 }
785 /* flush all data and free memory */
786 hdfreebeam(hp, 0);
787 hdsync(hp, 0);
788 /* release fragment resources */
789 hdrelease(hp->fd);
790 /* remove hp from active list */
791 for (i = 0; hdlist[i] != NULL; i++)
792 if (hdlist[i] == hp) {
793 while ((hdlist[i] = hdlist[i+1]) != NULL)
794 i++;
795 break;
796 }
797 free((char *)hp->bl); /* free beam list */
798 free((char *)hp); /* free holodeck struct */
799 }