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root/radiance/ray/src/hd/holofile.c
Revision: 3.16
Committed: Wed Dec 31 11:35:39 1997 UTC (26 years, 3 months ago) by gregl
Content type: text/plain
Branch: MAIN
Changes since 3.15: +41 -38 lines
Log Message: 
more minor improvements to hdsyncbeam()

File Contents

# User Rev Content
1 gregl 3.1 /* Copyright (c) 1997 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 gregl 3.5 #define FREEBEAMS 512 /* maximum beams to free at a time */
20 gregl 3.1 #endif
21     #ifndef PCTFREE
22 gregl 3.5 #define PCTFREE 20 /* maximum fraction to free (%) */
23 gregl 3.1 #endif
24 gregl 3.15 #ifndef MAXFRAG
25 gregl 3.16 #define MAXFRAG 32767 /* maximum fragments/file to track (0==inf) */
26 gregl 3.15 #endif
27 gregl 3.1
28 gregl 3.6 #ifndef BSD
29     #define write writebuf /* safe i/o routines */
30     #define read readbuf
31     #endif
32 gregl 3.4
33 gregl 3.16 #define FRAGBLK 256 /* number of fragments to allocate at a time */
34 gregl 3.4
35 gregl 3.14 unsigned hdcachesize = CACHESIZE*1024*1024; /* target cache size */
36 gregl 3.1 unsigned long hdclock; /* clock value */
37    
38     HOLO *hdlist[HDMAX+1]; /* holodeck pointers (NULL term.) */
39    
40 gregl 3.16 static struct fraglist {
41 gregl 3.1 short nlinks; /* number of holodeck sections using us */
42 gregl 3.13 short writerr; /* write error encountered */
43     int nfrags; /* number of known fragments */
44 gregl 3.4 BEAMI *fi; /* fragments, descending file position */
45 gregl 3.1 long flen; /* last known file length */
46 gregl 3.16 } *hdfragl; /* fragment lists, indexed by file descriptor */
47 gregl 3.1
48 gregl 3.16 static int nhdfragls; /* size of hdfragl array */
49 gregl 3.1
50 gregl 3.4
51 gregl 3.1 hdattach(fd) /* start tracking file fragments for some section */
52     register int fd;
53     {
54 gregl 3.16 if (fd >= nhdfragls) {
55     if (nhdfragls)
56     hdfragl = (struct fraglist *)realloc((char *)hdfragl,
57     (fd+1)*sizeof(struct fraglist));
58 gregl 3.4 else
59 gregl 3.16 hdfragl = (struct fraglist *)malloc(
60     (fd+1)*sizeof(struct fraglist));
61     if (hdfragl == NULL)
62 gregl 3.4 error(SYSTEM, "out of memory in hdattach");
63 gregl 3.16 bzero((char *)(hdfragl+nhdfragls),
64     (fd+1-nhdfragls)*sizeof(struct fraglist));
65     nhdfragls = fd+1;
66 gregl 3.1 }
67 gregl 3.16 hdfragl[fd].nlinks++;
68     hdfragl[fd].flen = lseek(fd, 0L, 2); /* get file length */
69 gregl 3.1 }
70    
71    
72     /* Do we need a routine to locate file fragments given known occupants? */
73    
74    
75     hdrelease(fd) /* stop tracking file fragments for some section */
76     register int fd;
77     {
78 gregl 3.16 if (fd < 0 | fd >= nhdfragls || !hdfragl[fd].nlinks)
79 gregl 3.1 return;
80 gregl 3.16 if (!--hdfragl[fd].nlinks && hdfragl[fd].nfrags) {
81     free((char *)hdfragl[fd].fi);
82     hdfragl[fd].fi = NULL;
83     hdfragl[fd].nfrags = 0;
84 gregl 3.1 }
85     }
86    
87    
88 gregl 3.6 markdirty(hp) /* mark holodeck section directory dirty */
89     register HOLO *hp;
90     {
91     static BEAMI smudge = {0, -1};
92    
93     if (hp->dirty) /* already marked? */
94     return;
95     hp->dirty = 1;
96     if (lseek(hp->fd, biglob(hp)->fo+(nbeams(hp)-1)*sizeof(BEAMI), 0) < 0
97     || write(hp->fd, (char *)&smudge,
98     sizeof(BEAMI)) != sizeof(BEAMI))
99     error(SYSTEM, "seek/write error in markdirty");
100     }
101    
102    
103 gregl 3.1 HOLO *
104     hdinit(fd, hproto) /* initialize a holodeck section in a file */
105     int fd; /* corresponding file descriptor */
106     HDGRID *hproto; /* holodeck section grid */
107     {
108     long fpos;
109     register HOLO *hp;
110     register int n;
111     /* prepare for system errors */
112     errno = 0;
113     if ((fpos = lseek(fd, 0L, 1)) < 0)
114     error(SYSTEM, "cannot determine holodeck file position");
115     if (hproto == NULL) { /* assume we're loading it */
116     HDGRID hpr;
117     /* load header */
118     if (read(fd, (char *)&hpr, sizeof(HDGRID)) != sizeof(HDGRID))
119     error(SYSTEM, "cannot load holodeck header");
120     /* allocate grid */
121     if ((hp = hdalloc(&hpr)) == NULL)
122     goto memerr;
123     /* load beam directory */
124     n = nbeams(hp)*sizeof(BEAMI);
125     if (read(fd, (char *)(hp->bi+1), n) != n)
126     error(SYSTEM, "failure loading holodeck directory");
127 gregl 3.6 /* check that it's clean */
128     if (hp->bi[nbeams(hp)].fo < 0)
129     error(USER, "dirty holodeck section");
130 gregl 3.1 } else { /* assume we're creating it */
131     if ((hp = hdalloc(hproto)) == NULL)
132     goto memerr;
133     /* write header and skeleton */
134     n = nbeams(hp)*sizeof(BEAMI);
135     if (write(fd, (char *)hproto, sizeof(HDGRID)) !=
136     sizeof(HDGRID) ||
137     write(fd, (char *)(hp->bi+1), n) != n)
138     error(SYSTEM, "cannot write header to holodeck file");
139     }
140     hp->fd = fd;
141     hp->dirty = 0;
142     biglob(hp)->fo = fpos + sizeof(HDGRID);
143 gregl 3.13 /* start tracking fragments */
144     hdattach(fd);
145     /* check rays on disk */
146     fpos = hdfilen(fd);
147     biglob(hp)->nrd = 0;
148     for (n = hproto == NULL ? nbeams(hp) : 0; n > 0; n--)
149     if (hp->bi[n].nrd)
150     if (hp->bi[n].fo + hp->bi[n].nrd > fpos)
151     hp->bi[n].nrd = 0; /* off end */
152     else
153     biglob(hp)->nrd += hp->bi[n].nrd;
154 gregl 3.1 /* add to holodeck list */
155     for (n = 0; n < HDMAX; n++)
156     if (hdlist[n] == NULL) {
157     hdlist[n] = hp;
158     break;
159     }
160     /* all done */
161     return(hp);
162     memerr:
163     error(SYSTEM, "cannot allocate holodeck grid");
164     }
165    
166    
167     int
168 gregl 3.12 hdsync(hp, all) /* update beams and directory on disk */
169 gregl 3.1 register HOLO *hp;
170 gregl 3.12 int all;
171 gregl 3.1 {
172     register int j, n;
173    
174 gregl 3.12 if (hp == NULL) { /* do all holodecks */
175 gregl 3.1 n = 0;
176     for (j = 0; hdlist[j] != NULL; j++)
177 gregl 3.12 n += hdsync(hdlist[j], all);
178 gregl 3.1 return(n);
179     }
180 gregl 3.12 /* sync the beams */
181 gregl 3.15 for (j = (all ? nbeams(hp) : 0); j > 0; j--)
182 gregl 3.12 if (hp->bl[j] != NULL)
183     hdsyncbeam(hp, j);
184 gregl 3.13 if (!hp->dirty) /* directory clean? */
185 gregl 3.1 return(0);
186 gregl 3.3 errno = 0;
187 gregl 3.1 if (lseek(hp->fd, biglob(hp)->fo, 0) < 0)
188     error(SYSTEM, "cannot seek on holodeck file");
189     n = nbeams(hp)*sizeof(BEAMI);
190     if (write(hp->fd, (char *)(hp->bi+1), n) != n)
191     error(SYSTEM, "cannot update holodeck section directory");
192     hp->dirty = 0;
193     return(1);
194     }
195    
196    
197 gregl 3.14 unsigned
198 gregl 3.1 hdmemuse(all) /* return memory usage (in bytes) */
199     int all; /* include overhead (painful) */
200     {
201     long total = 0;
202     register int i, j;
203    
204     for (j = 0; hdlist[j] != NULL; j++) {
205     total += blglob(hdlist[j])->nrm * sizeof(RAYVAL);
206     if (all) {
207     total += sizeof(HOLO) + sizeof(BEAM *) +
208     nbeams(hdlist[j]) *
209     (sizeof(BEAM *)+sizeof(BEAMI));
210     for (i = nbeams(hdlist[j]); i > 0; i--)
211     if (hdlist[j]->bl[i] != NULL)
212     total += sizeof(BEAM);
213     }
214     }
215     if (all)
216 gregl 3.16 for (j = 0; j < nhdfragls; j++) {
217     total += sizeof(struct fraglist);
218     if (hdfragl[j].nfrags)
219 gregl 3.4 total += FRAGBLK*sizeof(BEAMI) *
220 gregl 3.16 ((hdfragl[j].nfrags-1)/FRAGBLK + 1) ;
221 gregl 3.4 }
222 gregl 3.1 return(total);
223 gregl 3.8 }
224    
225    
226     long
227     hdfilen(fd) /* return file length for fd */
228     int fd;
229     {
230     long fpos, flen;
231    
232     if (fd < 0)
233     return(-1);
234 gregl 3.16 if (fd >= nhdfragls || !hdfragl[fd].nlinks) {
235 gregl 3.8 if ((fpos = lseek(fd, 0L, 1)) < 0)
236     return(-1);
237     flen = lseek(fd, 0L, 2);
238     lseek(fd, fpos, 0);
239     return(flen);
240     }
241 gregl 3.16 return(hdfragl[fd].flen);
242 gregl 3.1 }
243    
244    
245     long
246     hdfiluse(fd, all) /* compute file usage (in bytes) */
247     int fd; /* open file descriptor to check */
248     int all; /* include overhead and unflushed data */
249     {
250     long total = 0;
251     register int i, j;
252    
253     for (j = 0; hdlist[j] != NULL; j++) {
254     if (hdlist[j]->fd != fd)
255     continue;
256     total += biglob(hdlist[j])->nrd * sizeof(RAYVAL);
257     if (all) {
258     for (i = nbeams(hdlist[j]); i > 0; i--)
259     if (hdlist[j]->bl[i] != NULL)
260     total += sizeof(RAYVAL) *
261     (hdlist[j]->bl[i]->nrm -
262     hdlist[j]->bi[i].nrd);
263     total += sizeof(HDGRID) +
264     nbeams(hdlist[j])*sizeof(BEAMI);
265     }
266     }
267     return(total); /* does not include fragments */
268     }
269    
270    
271     RAYVAL *
272     hdnewrays(hp, i, nr) /* allocate space for add'l rays and return pointer */
273     register HOLO *hp;
274     register int i;
275     int nr; /* number of new rays desired */
276     {
277     RAYVAL *p;
278     int n;
279    
280     if (nr <= 0)
281     return(NULL);
282     if (i < 1 | i > nbeams(hp))
283     error(CONSISTENCY, "bad beam index given to hdnewrays");
284     if (hp->bl[i] != NULL)
285     hp->bl[i]->tick = hdclock; /* preempt swap */
286     if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
287     hdfreecache(PCTFREE, NULL); /* free some space */
288 gregl 3.3 errno = 0;
289 gregl 3.1 if (hp->bl[i] == NULL) { /* allocate (and load) */
290     n = hp->bi[i].nrd + nr;
291     if ((hp->bl[i] = (BEAM *)malloc(hdbsiz(n))) == NULL)
292     goto memerr;
293     blglob(hp)->nrm += n;
294     if (n = hp->bl[i]->nrm = hp->bi[i].nrd) {
295     if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
296     error(SYSTEM, "seek error on holodeck file");
297     n *= sizeof(RAYVAL);
298     if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
299     error(SYSTEM,
300     "error reading beam from holodeck file");
301     }
302     } else { /* just grow in memory */
303     hp->bl[i] = (BEAM *)realloc( (char *)hp->bl[i],
304     hdbsiz(hp->bl[i]->nrm + nr) );
305     if (hp->bl[i] == NULL)
306     goto memerr;
307     blglob(hp)->nrm += nr;
308     }
309     p = hdbray(hp->bl[i]) + hp->bl[i]->nrm;
310     hp->bl[i]->nrm += nr; /* update in-core structure */
311     bzero((char *)p, nr*sizeof(RAYVAL));
312 gregl 3.14 hp->bl[i]->tick = hdclock; /* update LRU clock */
313     blglob(hp)->tick = hdclock++;
314 gregl 3.1 return(p); /* point to new rays */
315     memerr:
316     error(SYSTEM, "out of memory in hdnewrays");
317     }
318    
319    
320     BEAM *
321     hdgetbeam(hp, i) /* get beam (from file if necessary) */
322     register HOLO *hp;
323     register int i;
324     {
325     register int n;
326    
327     if (i < 1 | i > nbeams(hp))
328     error(CONSISTENCY, "bad beam index given to hdgetbeam");
329     if (hp->bl[i] == NULL) { /* load from disk */
330     if (!(n = hp->bi[i].nrd))
331     return(NULL);
332     if (hdcachesize > 0 && hdmemuse(0) >= hdcachesize)
333     hdfreecache(PCTFREE, NULL); /* get free space */
334     errno = 0;
335     if ((hp->bl[i] = (BEAM *)malloc(hdbsiz(n))) == NULL)
336     error(SYSTEM, "cannot allocate memory for beam");
337     blglob(hp)->nrm += hp->bl[i]->nrm = n;
338     if (lseek(hp->fd, hp->bi[i].fo, 0) < 0)
339     error(SYSTEM, "seek error on holodeck file");
340     n *= sizeof(RAYVAL);
341     if (read(hp->fd, (char *)hdbray(hp->bl[i]), n) != n)
342     error(SYSTEM, "error reading beam from holodeck file");
343     }
344 gregl 3.14 hp->bl[i]->tick = hdclock; /* update LRU clock */
345     blglob(hp)->tick = hdclock++;
346 gregl 3.1 return(hp->bl[i]);
347     }
348    
349    
350     int
351 gregl 3.14 hdfilord(hb1, hb2) /* order beams for optimal loading */
352     register HDBEAMI *hb1, *hb2;
353     {
354     register int c;
355     /* sort by file descriptor first */
356     if ((c = hb1->h->fd - hb2->h->fd))
357     return(c);
358     /* then by position in file */
359     return(hb1->h->bi[hb1->b].fo - hb2->h->bi[hb2->b].fo);
360     }
361    
362    
363     hdloadbeams(hb, n, bf) /* load a list of beams in optimal order */
364     register HDBEAMI *hb; /* list gets sorted by hdfilord() */
365     int n; /* list length */
366     int (*bf)(); /* callback function (optional) */
367     {
368     unsigned origcachesize, memuse;
369     register BEAM *bp;
370     int bytesloaded, needbytes, bytes2free;
371     register int i;
372     /* precheck consistency */
373     for (i = n; i--; )
374     if (hb[i].h == NULL || hb[i].b < 1 | hb[i].b > nbeams(hb[i].h))
375     error(CONSISTENCY, "bad beam in hdloadbeams");
376     /* sort list for optimal access */
377     qsort((char *)hb, n, sizeof(HDBEAMI), hdfilord);
378     bytesloaded = needbytes = 0; /* figure out memory needs */
379 gregl 3.15 if ((origcachesize = hdcachesize) > 0) {
380     for (i = n; i--; )
381     if ((bp = hb[i].h->bl[hb[i].b]) != NULL) {
382     bp->tick = hdclock; /* preempt swap */
383     bytesloaded += bp->nrm;
384     } else /* prepare to load */
385     needbytes += hb[i].h->bi[hb[i].b].nrd;
386     bytesloaded *= sizeof(RAYVAL);
387     needbytes *= sizeof(RAYVAL);
388     do { /* free enough memory */
389     memuse = hdmemuse(0);
390     bytes2free = needbytes - (signed)(hdcachesize-memuse);
391     if (bytes2free > (signed)(memuse - bytesloaded))
392     bytes2free = memuse - bytesloaded;
393     } while (bytes2free > 0 &&
394     hdfreecache(100*bytes2free/memuse, NULL) < 0);
395     }
396 gregl 3.14 hdcachesize = 0; /* load the ordered beams w/o swap */
397     for (i = 0; i < n; i++)
398     if ((bp = hdgetbeam(hb[i].h, hb[i].b)) != NULL && bf != NULL)
399     (*bf)(bp, hb[i].h, hb[i].b);
400     hdcachesize = origcachesize; /* resume dynamic swapping */
401     }
402    
403    
404     int
405 gregl 3.12 hdsyncbeam(hp, i) /* sync beam in memory with beam on disk */
406 gregl 3.1 register HOLO *hp;
407     register int i;
408     {
409 gregl 3.12 unsigned int nrays;
410 gregl 3.11 long nfo;
411     unsigned int n;
412 gregl 3.13 /* check file status */
413 gregl 3.16 if (hdfragl[hp->fd].writerr)
414 gregl 3.13 return(-1);
415 gregl 3.12 #ifdef DEBUG
416     if (i < 1 | i > nbeams(hp))
417     error(CONSISTENCY, "bad beam index in hdsyncbeam");
418     #endif
419 gregl 3.11 /* is current fragment OK? */
420 gregl 3.12 if (hp->bl[i] == NULL || (nrays = hp->bl[i]->nrm) == hp->bi[i].nrd)
421 gregl 3.1 return(0);
422 gregl 3.13 /* locate fragment */
423 gregl 3.16 if (hp->fd >= nhdfragls || !hdfragl[hp->fd].nlinks) /* untracked */
424 gregl 3.1 hp->bi[i].fo = lseek(hp->fd, 0L, 2);
425    
426     else if (hp->bi[i].fo + hp->bi[i].nrd*sizeof(RAYVAL) ==
427 gregl 3.16 hdfragl[hp->fd].flen) /* EOF special case */
428     hdfragl[hp->fd].flen = (nfo=hp->bi[i].fo) + nrays*sizeof(RAYVAL);
429 gregl 3.1
430     else { /* general case */
431 gregl 3.16 register struct fraglist *f = &hdfragl[hp->fd];
432 gregl 3.1 register int j, k;
433 gregl 3.16 n = f->nfrags; /* relinquish old fragment */
434 gregl 3.2 if (hp->bi[i].nrd) {
435 gregl 3.5 j = f->nfrags++;
436 gregl 3.15 #if MAXFRAG
437 gregl 3.5 if (j >= MAXFRAG-1)
438 gregl 3.2 f->nfrags--;
439 gregl 3.4 #endif
440 gregl 3.5 if (j % FRAGBLK == 0) { /* more frag. space */
441 gregl 3.4 if (f->fi == NULL)
442     f->fi = (BEAMI *)malloc(
443     FRAGBLK*sizeof(BEAMI));
444     else
445     f->fi = (BEAMI *)realloc((char *)f->fi,
446 gregl 3.5 (j+FRAGBLK)*sizeof(BEAMI));
447 gregl 3.4 if (f->fi == NULL)
448     error(SYSTEM,
449 gregl 3.12 "out of memory in hdsyncbeam");
450 gregl 3.4 }
451 gregl 3.5 for ( ; ; j--) { /* insert in descending list */
452     if (!j || hp->bi[i].fo < f->fi[j-1].fo) {
453 gregl 3.2 f->fi[j].fo = hp->bi[i].fo;
454     f->fi[j].nrd = hp->bi[i].nrd;
455     break;
456     }
457 gregl 3.14 copystruct(f->fi+j, f->fi+(j-1));
458 gregl 3.1 }
459     /* coalesce adjacent fragments */
460 gregl 3.15 if (j && f->fi[j-1].fo == f->fi[j].fo +
461     f->fi[j].nrd*sizeof(RAYVAL)) {
462     f->fi[j].nrd += f->fi[j-1].nrd;
463     f->fi[j-1].nrd = 0;
464 gregl 3.16 n = j-1;
465 gregl 3.2 }
466 gregl 3.15 if (j+1 < f->nfrags && f->fi[j].fo == f->fi[j+1].fo +
467     f->fi[j+1].nrd*sizeof(RAYVAL)) {
468     f->fi[j+1].nrd += f->fi[j].nrd;
469     f->fi[j].nrd = 0;
470 gregl 3.16 if (j < n) n = j;
471 gregl 3.15 }
472 gregl 3.1 }
473     k = -1; /* find closest-sized fragment */
474 gregl 3.15 for (j = (nrays ? f->nfrags : 0); j-- > 0; )
475 gregl 3.1 if (f->fi[j].nrd >= nrays &&
476 gregl 3.3 (k < 0 || f->fi[j].nrd < f->fi[k].nrd))
477     if (f->fi[k=j].nrd == nrays)
478     break;
479 gregl 3.1 if (k < 0) { /* no fragment -- extend file */
480 gregl 3.11 nfo = f->flen;
481 gregl 3.1 f->flen += nrays*sizeof(RAYVAL);
482     } else { /* else use fragment */
483 gregl 3.11 nfo = f->fi[k].fo;
484 gregl 3.15 f->fi[k].fo += nrays*sizeof(RAYVAL);
485 gregl 3.16 if (!(f->fi[k].nrd -= nrays) && k < n)
486     n = k;
487 gregl 3.1 }
488 gregl 3.15 /* delete empty remnants */
489 gregl 3.16 for (j = k = n; k < f->nfrags; j++, k++) {
490 gregl 3.15 while (f->fi[k].nrd == 0)
491     if (++k >= f->nfrags)
492     goto endloop;
493     if (k > j)
494     copystruct(f->fi+j, f->fi+k);
495     }
496     endloop:
497     f->nfrags = j;
498 gregl 3.1 }
499 gregl 3.11 if (nrays) { /* write the new fragment */
500     errno = 0;
501     if (lseek(hp->fd, nfo, 0) < 0)
502     error(SYSTEM, "cannot seek on holodeck file");
503     n = hp->bl[i]->nrm * sizeof(RAYVAL);
504     if (write(hp->fd, (char *)hdbray(hp->bl[i]), n) != n) {
505 gregl 3.16 hdfragl[hp->fd].writerr++;
506 gregl 3.13 hdsync(hp, 0); /* sync directory */
507 gregl 3.12 error(SYSTEM, "write error in hdsyncbeam");
508 gregl 3.11 }
509     }
510 gregl 3.1 biglob(hp)->nrd += nrays - hp->bi[i].nrd;
511     hp->bi[i].nrd = nrays;
512 gregl 3.11 hp->bi[i].fo = nfo;
513 gregl 3.6 markdirty(hp); /* section directory now out of date */
514 gregl 3.1 return(1);
515     }
516    
517    
518     int
519     hdfreebeam(hp, i) /* free beam, writing if dirty */
520     register HOLO *hp;
521     register int i;
522     {
523 gregl 3.11 int nchanged;
524 gregl 3.1
525     if (hp == NULL) { /* clear all holodecks */
526     nchanged = 0;
527     for (i = 0; hdlist[i] != NULL; i++)
528     nchanged += hdfreebeam(hdlist[i], 0);
529     return(nchanged);
530     }
531 gregl 3.16 if (hdfragl[hp->fd].writerr) /* check for file error */
532 gregl 3.13 return(0);
533 gregl 3.1 if (i == 0) { /* clear entire holodeck */
534     nchanged = 0;
535 gregl 3.10 for (i = nbeams(hp); i > 0; i--)
536     if (hp->bl[i] != NULL)
537     nchanged += hdfreebeam(hp, i);
538 gregl 3.1 return(nchanged);
539     }
540 gregl 3.12 #ifdef DEBUG
541 gregl 3.1 if (i < 1 | i > nbeams(hp))
542     error(CONSISTENCY, "bad beam index to hdfreebeam");
543 gregl 3.12 #endif
544 gregl 3.1 if (hp->bl[i] == NULL)
545     return(0);
546     /* check for additions */
547     nchanged = hp->bl[i]->nrm - hp->bi[i].nrd;
548 gregl 3.11 if (nchanged)
549 gregl 3.12 hdsyncbeam(hp, i); /* write new fragment */
550 gregl 3.1 blglob(hp)->nrm -= hp->bl[i]->nrm;
551     free((char *)hp->bl[i]); /* free memory */
552     hp->bl[i] = NULL;
553     return(nchanged);
554     }
555    
556    
557 gregl 3.10 int
558     hdkillbeam(hp, i) /* delete beam from holodeck */
559     register HOLO *hp;
560     register int i;
561     {
562     static BEAM emptybeam;
563 gregl 3.11 int nchanged;
564 gregl 3.10
565     if (hp == NULL) { /* clobber all holodecks */
566     nchanged = 0;
567     for (i = 0; hdlist[i] != NULL; i++)
568     nchanged += hdkillbeam(hdlist[i], 0);
569     return(nchanged);
570     }
571     if (i == 0) { /* clobber entire holodeck */
572     nchanged = 0;
573     for (i = nbeams(hp); i > 0; i--)
574     if (hp->bi[i].nrd > 0 || hp->bl[i] != NULL)
575     nchanged += hdkillbeam(hp, i);
576     #ifdef DEBUG
577     if (biglob(hp)->nrd != 0 | blglob(hp)->nrm != 0)
578     error(CONSISTENCY, "bad beam count in hdkillbeam");
579     #endif
580     return(nchanged);
581     }
582 gregl 3.12 #ifdef DEBUG
583 gregl 3.10 if (i < 1 | i > nbeams(hp))
584     error(CONSISTENCY, "bad beam index to hdkillbeam");
585 gregl 3.12 #endif
586 gregl 3.10 if (hp->bl[i] != NULL) { /* free memory */
587     blglob(hp)->nrm -= nchanged = hp->bl[i]->nrm;
588     free((char *)hp->bl[i]);
589     } else
590     nchanged = hp->bi[i].nrd;
591     if (hp->bi[i].nrd) { /* free file fragment */
592     hp->bl[i] = &emptybeam;
593 gregl 3.12 hdsyncbeam(hp, i);
594 gregl 3.10 }
595     hp->bl[i] = NULL;
596     return(nchanged);
597     }
598    
599    
600 gregl 3.14 int
601     hdlrulist(hb, nents, n, hp) /* add beams from holodeck to LRU list */
602     register HDBEAMI *hb; /* beam list */
603     int nents; /* current list length */
604     int n; /* maximum list length */
605 gregl 3.1 register HOLO *hp; /* section we're adding from */
606     {
607     register int i, j;
608     /* insert each beam from hp */
609 gregl 3.10 for (i = nbeams(hp); i > 0; i--) {
610 gregl 3.1 if (hp->bl[i] == NULL) /* check if loaded */
611     continue;
612 gregl 3.14 #if 0
613     if (hp->bl[i]->tick == hdclock) /* preempt swap? */
614     continue;
615     #endif
616     if ((j = ++nents) >= n) /* grow list if we can */
617 gregl 3.1 nents--;
618     for ( ; ; ) { /* bubble into place */
619     if (!--j || hp->bl[i]->tick >=
620 gregl 3.14 hb[j-1].h->bl[hb[j-1].b]->tick) {
621     hb[j].h = hp;
622     hb[j].b = i;
623 gregl 3.1 break;
624     }
625 gregl 3.14 copystruct(hb+j, hb+(j-1));
626 gregl 3.1 }
627     }
628 gregl 3.14 return(nents); /* return new list length */
629 gregl 3.1 }
630    
631    
632 gregl 3.14 int
633 gregl 3.1 hdfreecache(pct, honly) /* free up cache space, writing changes */
634     int pct; /* maximum percentage to free */
635     register HOLO *honly; /* NULL means check all */
636     {
637 gregl 3.14 HDBEAMI hb[FREEBEAMS];
638 gregl 3.1 int freetarget;
639 gregl 3.14 int n;
640 gregl 3.1 register int i;
641     /* compute free target */
642     freetarget = (honly != NULL) ? blglob(honly)->nrm :
643     hdmemuse(0)/sizeof(RAYVAL) ;
644     freetarget = freetarget*pct/100;
645 gregl 3.14 if (freetarget <= 0)
646     return(0);
647 gregl 3.1 /* find least recently used */
648 gregl 3.14 n = 0;
649 gregl 3.1 if (honly != NULL)
650 gregl 3.14 n = hdlrulist(hb, n, FREEBEAMS, honly);
651 gregl 3.1 else
652     for (i = 0; hdlist[i] != NULL; i++)
653 gregl 3.14 n = hdlrulist(hb, n, FREEBEAMS, hdlist[i]);
654 gregl 3.1 /* free LRU beams */
655 gregl 3.14 for (i = 0; i < n; i++) {
656     hdfreebeam(hb[i].h, hb[i].b);
657     if ((freetarget -= hb[i].h->bi[hb[i].b].nrd) <= 0)
658 gregl 3.1 break;
659     }
660 gregl 3.12 hdsync(honly, 0); /* synchronize directories as necessary */
661 gregl 3.14 return(-freetarget); /* return how far past goal we went */
662 gregl 3.1 }
663    
664    
665     hddone(hp) /* clean up holodeck section and free */
666     register HOLO *hp; /* NULL means clean up all */
667     {
668     register int i;
669    
670     if (hp == NULL) { /* NULL means clean up everything */
671     while (hdlist[0] != NULL)
672     hddone(hdlist[0]);
673     return;
674     }
675     /* flush all data and free memory */
676     hdflush(hp);
677     /* release fragment resources */
678     hdrelease(hp->fd);
679     /* remove hp from active list */
680     for (i = 0; hdlist[i] != NULL; i++)
681     if (hdlist[i] == hp) {
682     while ((hdlist[i] = hdlist[i+1]) != NULL)
683     i++;
684     break;
685     }
686     free((char *)hp->bl); /* free beam list */
687     free((char *)hp); /* free holodeck struct */
688     }