1999/0807/mpc/devsac.c (diff list | history)

1999/0608/sys/src/9/mpc/devsac.c:4,9 – 1999/0609/sys/src/9/mpc/devsac.c:4,10 (short | long)
1999/0608		#include "dat.h" #include "fns.h" #include "io.h"
1999/0609		#include "../port/error.h"
1999/0608		/* * Rather than reading /adm/users, which is a lot of work for
1999/0608/sys/src/9/mpc/devsac.c:73,104 – 1999/0609/sys/src/9/mpc/devsac.c:74,104
1999/0608		Powner = 64, }; uchar *data = SACMEM; int blocksize; Sac root;
1999/0609		static uchar *data = SACMEM; static int blocksize; static Sac root;
1999/0608		void sacstat(SacDir*, char*); void io(void); void usage(void); ulong getl(void *p); vlong getv(void *p); void init(char*); Sac *saccpy(Sac *s); Sac *saclookup(Sac *s, char *name); int sacdirread(Sac *s, char *p, long off, long cnt); void loadblock(void *buf, uchar *offset, int blocksize); void sacfree(Sac*);
1999/0609		static void sacdir(Chan *, SacDir*, char*); static ulong getl(void *p); static vlong getv(void *p); static Sac *saccpy(Sac *s); static Sac *saclookup(Sac *s, char *name); static int sacdirread(Chan *, char *p, long off, long cnt); static void loadblock(void *buf, uchar *offset, int blocksize); static void sacfree(Sac*);
1999/0608		void devinit(void)
1999/0609		static void sacinit(void)
1999/0608		{ SacHeader *hdr;
1999/0609		print("sacinit\n");
1999/0608		hdr = (SacHeader*)data; if(getl(hdr->magic) != Magic) { print("devsac: bad magic");
1999/0609		print("devsac: bad magic\n");
1999/0608		return; } blocksize = getl(hdr->blocksize);
1999/0609		print("blocksize = %d\n", blocksize);
1999/0608		root.SacDir = *(SacDir*)(data + sizeof(SacHeader)); }
1999/0608/sys/src/9/mpc/devsac.c:123,129 – 1999/0609/sys/src/9/mpc/devsac.c:123,129
1999/0608		return c; } Chan*
1999/0609		static Chan*
1999/0608		sacclone(Chan *c, Chan *nc) { nc = devclone(c, nc);
1999/0608/sys/src/9/mpc/devsac.c:131,145 – 1999/0609/sys/src/9/mpc/devsac.c:131,147
1999/0608		return nc; } int devwalk(Chan *c, char *name, Dirtab *tab, int ntab, Devgen *gen)
1999/0609		static int sacwalk(Chan *c, char *name)
1999/0608		{ Sac *sac;
1999/0609		Path *op;
1999/0608
1999/0609		print("sacwalk\n");
1999/0608		isdir(c); sac = c->aux; if(strcmp(name, ".") == 0)
1999/0609		if(name[0]=='.' && name[1]==0)
1999/0608		return 1;
1999/0609		sac = c->aux;
1999/0608		sac = saclookup(sac, name); if(sac == nil) { strncpy(up->error, Enonexist, NAMELEN);
1999/0608/sys/src/9/mpc/devsac.c:148,235 – 1999/0609/sys/src/9/mpc/devsac.c:150,214
1999/0608		c->aux = sac; c->qid = (Qid){getl(sac->qid), 0}; op = c->path;
1999/0609		print("op=%ux name = %s\n", op, name);
1999/0608		c->path = ptenter(&syspt, op, name); decref(op); return 1; } char * ropen(Fid *f)
1999/0609		static Chan* sacopen(Chan *c, int omode)
1999/0608		{ int mode, trunc;
1999/0609		ulong t, mode; Sac *sac; static int access[] = { 0400, 0200, 0600, 0100 };
1999/0608		if(f->open) return Eisopen; if(f->busy == 0) return Enotexist; mode = rhdr.mode; if(f->qid.path & CHDIR){ if(mode != OREAD) return Eperm; thdr.qid = f->qid; return 0; } if(mode & ORCLOSE) return Erdonly; trunc = mode & OTRUNC; mode &= OPERM; if(mode==OWRITE || mode==ORDWR || trunc) return Erdonly; if(mode==OREAD) if(!perm(f, f->sac, Pread)) return Eperm; if(mode==OEXEC) if(!perm(f, f->sac, Pexec)) return Eperm; thdr.qid = f->qid; f->open = 1; return 0; }
1999/0609		sac = c->aux; mode = getl(sac->mode); if(strcmp(up->user, sac->uid) == 0) mode = mode; else if(strcmp(up->user, sac->gid) == 0) mode = mode<<3; else mode = mode<<6;
1999/0608		char * rcreate(Fid *f) { if(f->open) return Eisopen; if(f->busy == 0) return Enotexist; return Erdonly;
1999/0609		t = access[omode&3]; if((t & mode) != t) error(Eperm); c->offset = 0; c->mode = openmode(omode); c->flag |= COPEN; return c;
1999/0608		} char* rread(Fid *f)
1999/0609		static long sacread(Chan *c, void *a, long n, vlong off)
1999/0608		{ Sac *sac; char *buf, *buf2; long off; int n, cnt, i, j;
1999/0609		int nn, cnt, i, j;
1999/0608		uchar *blocks; vlong length; if(f->busy == 0) return Enotexist; sac = f->sac; thdr.count = 0; off = rhdr.offset; buf = thdr.data; cnt = rhdr.count; if(f->qid.path & CHDIR){ cnt = (rhdr.count/DIRLEN)*DIRLEN;
1999/0609		buf = a; cnt = n; if(c->qid.path & CHDIR){ cnt = (cnt/DIRLEN)*DIRLEN;
1999/0608		if(off%DIRLEN) return "i/o error"; thdr.count = sacdirread(sac, buf, off, cnt); return 0;
1999/0609		error("i/o error"); return sacdirread(c, buf, off, cnt);
1999/0608		}
1999/0609		print("data read\n"); sac = c->aux;
1999/0608		length = getv(sac->length); if(off >= length) { rhdr.count = 0;
1999/0609		if(off >= length)
1999/0608		return 0; } if(cnt > length-off) cnt = length-off; thdr.count = cnt; if(cnt == 0) return 0;
1999/0609		n = cnt;
1999/0608		blocks = data + getv(sac->blocks); buf2 = malloc(blocksize); while(cnt > 0) {
1999/0608/sys/src/9/mpc/devsac.c:236,303 – 1999/0609/sys/src/9/mpc/devsac.c:215,261
1999/0608		i = off/blocksize; loadblock(buf2, blocks+i*8, blocksize); j = off-i*blocksize; n = blocksize-j; if(n > cnt) n = cnt; memmove(buf, buf2+j, n); cnt -= n; off += n;
1999/0609		nn = blocksize-j; if(nn > cnt) nn = cnt; memmove(buf, buf2+j, nn); cnt -= nn; off += nn;
1999/0608		} free(buf2); return 0;
1999/0609		return n;
1999/0608		} char* sacwrite(Fid *f)
1999/0609		static long sacwrite(Chan *, void *, long, vlong)
1999/0608		{ if(f->busy == 0) return Enotexist; return Erdonly; }                  char * rclunk(Fid *f) { f->busy = 0; f->open = 0; free(f->user); sacfree(f->sac);
1999/0609		error(Eperm);
1999/0608		return 0; } char * rremove(Fid *f)
1999/0609		static void sacclose(Chan* c)
1999/0608		{ f->busy = 0; f->open = 0; free(f->user); sacfree(f->sac); return Erdonly;
1999/0609		Sac *sac = c->aux; print("close %ux\n", sac); c->aux = nil; sacfree(sac);
1999/0608		} char * rstat(Fid *f) { if(f->busy == 0) return Enotexist; sacstat(f->sac, thdr.stat); return 0; } char * rwstat(Fid *f)
1999/0609		static void sacstat(Chan *c, char *db)
1999/0608		{ if(f->busy == 0) return Enotexist; return Erdonly;
1999/0609		sacdir(c, c->aux, db);
1999/0608		} Sac*
1999/0609		static Sac*
1999/0608		saccpy(Sac *s) { Sac *ss; ss = malloc(sizeof(Sac));
1999/0609		print("saccpy = %ux\n", ss);
1999/0608		*ss = *s; if(ss->path) incref(ss->path);
1999/0608/sys/src/9/mpc/devsac.c:304,310 – 1999/0609/sys/src/9/mpc/devsac.c:262,268
1999/0608		return ss; } SacPath *
1999/0609		static SacPath *
1999/0608		sacpathalloc(SacPath *p, vlong blocks, int entry) { SacPath *pp = malloc(sizeof(SacPath));
1999/0608/sys/src/9/mpc/devsac.c:327,333 – 1999/0609/sys/src/9/mpc/devsac.c:285,291
1999/0608		} void
1999/0609		static void
1999/0608		sacfree(Sac *s) { sacpathfree(s->path);
1999/0608/sys/src/9/mpc/devsac.c:334,341 – 1999/0609/sys/src/9/mpc/devsac.c:292,299
1999/0608		free(s); } void sacstat(SacDir *s, char *buf)
1999/0609		static void sacdir(Chan *c, SacDir *s, char *buf)
1999/0608		{ Dir dir;
1999/0608/sys/src/9/mpc/devsac.c:349,358 – 1999/0609/sys/src/9/mpc/devsac.c:307,318
1999/0608		strcpy(dir.gid, s->gid); dir.atime = getl(s->atime); dir.mtime = getl(s->mtime);
1999/0609		dir.type = devtab[c->type]->dc; dir.dev = c->dev;
1999/0608		convD2M(&dir, buf); } void
1999/0609		static void
1999/0608		loadblock(void *buf, uchar *offset, int blocksize) { vlong block, n;
1999/0608/sys/src/9/mpc/devsac.c:364,378 – 1999/0609/sys/src/9/mpc/devsac.c:324,339
1999/0608		if(n < 0) n = -n; n -= block; //fprint(2, "blocksize = %d, block = %lld n = %lld\n", blocksize, block, n);
1999/0609		print("blocksize = %d, block = %lld n = %lld\n", blocksize, block, n);
1999/0608		if(unsac(buf, data+block, blocksize, n)<0) panic("unsac failed!"); } else {
1999/0609		print("memmove: blocksize = %d\n", blocksize);
1999/0608		memmove(buf, data+block, blocksize); } } Sac*
1999/0609		static Sac*
1999/0608		sacparent(Sac *s) { uchar *blocks;
1999/0608/sys/src/9/mpc/devsac.c:382,394 – 1999/0609/sys/src/9/mpc/devsac.c:343,355
1999/0608		p = s->path; if(p == nil || p->up == nil) { pathfree(p);
1999/0609		sacpathfree(p);
1999/0608		*s = root; return s; } p = p->up; //fprint(2, "sacparent = %lld %d\n", p->blocks, p->entry);
1999/0609		print("sacparent = %lld %d\n", p->blocks, p->entry);
1999/0608		blocks = data + p->blocks; per = blocksize/sizeof(SacDir); i = p->entry/per;
1999/0608/sys/src/9/mpc/devsac.c:395,415 – 1999/0609/sys/src/9/mpc/devsac.c:356,379
1999/0608		buf = malloc(per*sizeof(SacDir)); loadblock(buf, blocks + i*8, per*sizeof(SacDir)); s->SacDir = buf[p->entry-i*per]; //fprint(2, "sacparent = %s\n", s->name);
1999/0609		print("sacparent = %s\n", s->name);
1999/0608		free(buf); incref(p); pathfree(s->path);
1999/0609		sacpathfree(s->path);
1999/0608		s->path = p; return s; } int sacdirread(Sac *s, char *p, long off, long cnt)
1999/0609		static int sacdirread(Chan *c, char *p, long off, long cnt)
1999/0608		{ uchar *blocks; SacDir *buf; int iblock, per, i, j, ndir;
1999/0609		Sac *s;
1999/0608
1999/0609		print("sacdirread %d %d\n", off, cnt); s = c->aux;
1999/0608		blocks = data + getv(s->blocks); per = blocksize/sizeof(SacDir); ndir = getv(s->length);
1999/0608/sys/src/9/mpc/devsac.c:428,434 – 1999/0609/sys/src/9/mpc/devsac.c:392,398
1999/0608		iblock = j; } j *= per; sacstat(buf+i-j, p);
1999/0609		sacdir(c, buf+i-j, p);
1999/0608		p += DIRLEN; } free(buf);
1999/0608/sys/src/9/mpc/devsac.c:435,445 – 1999/0609/sys/src/9/mpc/devsac.c:399,409
1999/0608		return cnt*DIRLEN; } Sac*
1999/0609		static Sac*
1999/0608		saclookup(Sac *s, char *name) { int ndir; int top, bot, i, j, k, per;
1999/0609		int i, j, k, per;
1999/0608		uchar *blocks; SacDir *buf; int iblock;
1999/0608/sys/src/9/mpc/devsac.c:453,488 – 1999/0609/sys/src/9/mpc/devsac.c:417,424
1999/0608		buf = malloc(per*sizeof(SacDir)); iblock = -1; if(1) { // linear search for(i=0; i<ndir; i++) { j = i/per; if(j != iblock) { loadblock(buf, blocks + j*8, per*sizeof(SacDir)); iblock = j; } j *= per; sd = buf+i-j; k = strcmp(name, sd->name); if(k == 0) { //print("walk %s %lld %d\n", name, getv(s->blocks), i); s->path = sacpathalloc(s->path, getv(s->blocks), i); s->SacDir = *sd; free(buf); return s; } } free(buf); return 0; }                  // binary search top = ndir; bot = 0; while(bot != top){ if(bot>top) sysfatal("binary serach failed: %d %d\n", bot, top); i = (bot+top)>>1;
1999/0609		// linear search for(i=0; i<ndir; i++) {
1999/0608		j = i/per; if(j != iblock) { loadblock(buf, blocks + j*8, per*sizeof(SacDir));
1999/0608/sys/src/9/mpc/devsac.c:492,606 – 1999/0609/sys/src/9/mpc/devsac.c:428,445
1999/0608		sd = buf+i-j; k = strcmp(name, sd->name); if(k == 0) { s->path = sacpathalloc(s->path, getv(s->blocks), i);
1999/0609		print("walk %s %lld %d\n", name, getv(s->blocks), i); s->path = sacpathalloc(s->path, getv(s->blocks), i);
1999/0608		s->SacDir = *sd; free(buf);
1999/0609		return s;
1999/0608		} if(k < 0) { top = i; sd = buf; if(strcmp(name, sd->name) < 0) top = j; } else { bot = i+1; if(ndir-j < per) i = ndir-j; else i = per; sd = buf+i-1; if(strcmp(name, sd->name) > 0) bot = j+i; } }
1999/0609		free(buf);
1999/0608		return 0; } Fid * newfid(int fid) { Fid *f, *ff;                  ff = 0; for(f = fids; f; f = f->next) if(f->fid == fid) return f; else if(!ff && !f->busy) ff = f; if(ff){ ff->fid = fid; return ff; } f = malloc(sizeof *f); //fprint(2, "newfid\n"); memset(f, 0 , sizeof(Fid)); f->fid = fid; f->next = fids; fids = f; return f; }                  void io(void) { char *err; int n;                  for(;;){ /* * reading from a pipe or a network device * will give an error after a few eof reads * however, we cannot tell the difference * between a zero-length read and an interrupt * on the processes writing to us, * so we wait for the error */ n = read(mfd[0], mdata, sizeof mdata); if(n == 0) continue; if(n < 0) error("mount read"); if(convM2S(mdata, &rhdr, n) == 0) continue;                  if(debug) fprint(2, "sacfs:<-%F\n", &rhdr);                  thdr.data = mdata + MAXMSG; if(!fcalls[rhdr.type]) err = "bad fcall type"; else err = (*fcalls[rhdr.type])(newfid(rhdr.fid)); if(err){ thdr.type = Rerror; strncpy(thdr.ename, err, ERRLEN); }else{ thdr.type = rhdr.type + 1; thdr.fid = rhdr.fid; } thdr.tag = rhdr.tag; if(debug) fprint(2, "ramfs:->%F\n", &thdr);/**/ n = convS2M(&thdr, mdata); if(write(mfd[1], mdata, n) != n) error("mount write"); } }                  int perm(Fid *f, Sac *s, int p) { ulong perm = getl(s->mode); if((p*Pother) & perm) return 1; if(strcmp(f->user, s->gid)==0 && ((p*Pgroup) & perm)) return 1; if(strcmp(f->user, s->uid)==0 && ((p*Powner) & perm)) return 1; return 0; }                                   ulong
1999/0609		static ulong
1999/0608		getl(void *p) { uchar *a = p;
1999/0608/sys/src/9/mpc/devsac.c:608,614 – 1999/0609/sys/src/9/mpc/devsac.c:447,453
1999/0608		return (a[0]<<24) | (a[1]<<16) | (a[2]<<8) | a[3]; } vlong
1999/0609		static vlong
1999/0608		getv(void *p) { uchar *a = p;
1999/0609/sys/src/9/mpc/devsac.c:98,104 – 1999/0610/sys/src/9/mpc/devsac.c:98,103 (short | long)
1999/0608		return; } blocksize = getl(hdr->blocksize);
1999/0609		print("blocksize = %d\n", blocksize);
1999/0608		root.SacDir = *(SacDir*)(data + sizeof(SacHeader)); }
1999/0609/sys/src/9/mpc/devsac.c:137,143 – 1999/0610/sys/src/9/mpc/devsac.c:136,143
1999/0608		Sac *sac;
1999/0609		Path *op;
1999/0608
1999/0609		print("sacwalk\n");
1999/0610		//print("walk %s\n", name);
1999/0608		isdir(c);
1999/0609		if(name[0]=='.' && name[1]==0)
1999/0608		return 1;
1999/0609/sys/src/9/mpc/devsac.c:150,156 – 1999/0610/sys/src/9/mpc/devsac.c:150,155
1999/0608		c->aux = sac; c->qid = (Qid){getl(sac->qid), 0}; op = c->path;
1999/0609		print("op=%ux name = %s\n", op, name);
1999/0608		c->path = ptenter(&syspt, op, name); decref(op); return 1;
1999/0609/sys/src/9/mpc/devsac.c:199,206 – 1999/0610/sys/src/9/mpc/devsac.c:198,205
1999/0609		error("i/o error"); return sacdirread(c, buf, off, cnt);
1999/0608		}
1999/0609		print("data read\n"); sac = c->aux;
1999/0610		//print("sacread: %s %llx %d\n", sac->name, off, n);
1999/0608		length = getv(sac->length);
1999/0609		if(off >= length)
1999/0608		return 0;
1999/0609/sys/src/9/mpc/devsac.c:221,226 – 1999/0610/sys/src/9/mpc/devsac.c:220,226
1999/0609		memmove(buf, buf2+j, nn); cnt -= nn; off += nn;
1999/0610		buf += nn;
1999/0608		} free(buf2);
1999/0609		return n;
1999/0609/sys/src/9/mpc/devsac.c:237,243 – 1999/0610/sys/src/9/mpc/devsac.c:237,242
1999/0609		sacclose(Chan* c)
1999/0608		{
1999/0609		Sac *sac = c->aux; print("close %ux\n", sac); c->aux = nil; sacfree(sac);
1999/0608		}
1999/0609/sys/src/9/mpc/devsac.c:255,261 – 1999/0610/sys/src/9/mpc/devsac.c:254,259
1999/0608		Sac *ss; ss = malloc(sizeof(Sac));
1999/0609		print("saccpy = %ux\n", ss);
1999/0608		*ss = *s; if(ss->path) incref(ss->path);
1999/0609/sys/src/9/mpc/devsac.c:324,334 – 1999/0610/sys/src/9/mpc/devsac.c:322,330
1999/0608		if(n < 0) n = -n; n -= block;
1999/0609		print("blocksize = %d, block = %lld n = %lld\n", blocksize, block, n);
1999/0608		if(unsac(buf, data+block, blocksize, n)<0) panic("unsac failed!"); } else {
1999/0609		print("memmove: blocksize = %d\n", blocksize);
1999/0608		memmove(buf, data+block, blocksize); } }
1999/0609/sys/src/9/mpc/devsac.c:349,355 – 1999/0610/sys/src/9/mpc/devsac.c:345,350
1999/0608		} p = p->up;
1999/0609		print("sacparent = %lld %d\n", p->blocks, p->entry);
1999/0608		blocks = data + p->blocks; per = blocksize/sizeof(SacDir); i = p->entry/per;
1999/0609/sys/src/9/mpc/devsac.c:356,362 – 1999/0610/sys/src/9/mpc/devsac.c:351,356
1999/0608		buf = malloc(per*sizeof(SacDir)); loadblock(buf, blocks + i*8, per*sizeof(SacDir)); s->SacDir = buf[p->entry-i*per];
1999/0609		print("sacparent = %s\n", s->name);
1999/0608		free(buf); incref(p);
1999/0609		sacpathfree(s->path);
1999/0609/sys/src/9/mpc/devsac.c:372,378 – 1999/0610/sys/src/9/mpc/devsac.c:366,371
1999/0608		int iblock, per, i, j, ndir;
1999/0609		Sac *s;
1999/0608
1999/0609		print("sacdirread %d %d\n", off, cnt); s = c->aux;
1999/0608		blocks = data + getv(s->blocks); per = blocksize/sizeof(SacDir);
1999/0609/sys/src/9/mpc/devsac.c:428,434 – 1999/0610/sys/src/9/mpc/devsac.c:421,426
1999/0608		sd = buf+i-j; k = strcmp(name, sd->name); if(k == 0) {
1999/0609		print("walk %s %lld %d\n", name, getv(s->blocks), i); s->path = sacpathalloc(s->path, getv(s->blocks), i);
1999/0608		s->SacDir = *sd; free(buf);
1999/0610/sys/src/9/mpc/devsac.c:134,140 – 1999/0727/sys/src/9/mpc/devsac.c:134,139 (short | long)
1999/0609		sacwalk(Chan *c, char *name)
1999/0608		{ Sac *sac;
1999/0609		Path *op;
1999/0608
1999/0610		//print("walk %s\n", name);
1999/0610/sys/src/9/mpc/devsac.c:149,157 – 1999/0727/sys/src/9/mpc/devsac.c:148,153
1999/0608		} c->aux = sac; c->qid = (Qid){getl(sac->qid), 0}; op = c->path; c->path = ptenter(&syspt, op, name); decref(op); return 1; }
1999/0727/sys/src/9/mpc/devsac.c:17,22 – 1999/0806/sys/src/9/mpc/devsac.c:17,23 (short | long)
1999/0608		{ OPERM = 0x3, /* mask of all permission types in open mode */ Nram = 512,
1999/0806		CacheSize = 20,
1999/0608		}; typedef struct SacPath SacPath;
1999/0727/sys/src/9/mpc/devsac.c:23,28 – 1999/0806/sys/src/9/mpc/devsac.c:24,30
1999/0608		typedef struct Sac Sac; typedef struct SacHeader SacHeader; typedef struct SacDir SacDir;
1999/0806		typedef struct Cache Cache;
1999/0608		enum { Magic = 0x5acf5,
1999/0727/sys/src/9/mpc/devsac.c:64,69 – 1999/0806/sys/src/9/mpc/devsac.c:66,78
1999/0608		int entry; };
1999/0806		struct Cache { long block; ulong age; uchar *data; };
1999/0608		enum { Pexec = 1,
1999/0727/sys/src/9/mpc/devsac.c:77,82 – 1999/0806/sys/src/9/mpc/devsac.c:86,93
1999/0609		static uchar *data = SACMEM; static int blocksize; static Sac root;
1999/0806		static Cache cache[CacheSize]; static ulong cacheage;
1999/0608
1999/0609		static void sacdir(Chan *, SacDir*, char*); static ulong getl(void *p);
1999/0727/sys/src/9/mpc/devsac.c:91,96 – 1999/0806/sys/src/9/mpc/devsac.c:102,110
1999/0609		sacinit(void)
1999/0608		{ SacHeader *hdr;
1999/0806		uchar *p; int i;
1999/0609		print("sacinit\n");
1999/0608		hdr = (SacHeader*)data; if(getl(hdr->magic) != Magic) {
1999/0727/sys/src/9/mpc/devsac.c:99,104 – 1999/0806/sys/src/9/mpc/devsac.c:113,125
1999/0608		} blocksize = getl(hdr->blocksize); root.SacDir = *(SacDir*)(data + sizeof(SacHeader));
1999/0806		p = malloc(CacheSize*blocksize); if(p == nil) error("allocating cache"); for(i=0; i<CacheSize; i++) { cache[i].data = p; p += blocksize; }
1999/0608		} static Chan*
1999/0727/sys/src/9/mpc/devsac.c:310,319 – 1999/0806/sys/src/9/mpc/devsac.c:331,362
1999/0608		loadblock(void *buf, uchar *offset, int blocksize) { vlong block, n;
1999/0806		ulong age; int i, j;
1999/0608		block = getv(offset); if(block < 0) { block = -block;
1999/0806		cacheage++; // age has wraped if(cacheage == 0) { for(i=0; i<CacheSize; i++) cache[i].age = 0; } j = 0; age = cache[0].age; for(i=0; i<CacheSize; i++) { if(cache[i].age < age) { age = cache[i].age; j = i; } if(cache[i].block != block) continue; memmove(buf, cache[i].data, blocksize); cache[i].age = cacheage; return; }
1999/0608		n = getv(offset+8); if(n < 0) n = -n;
1999/0727/sys/src/9/mpc/devsac.c:320,325 – 1999/0806/sys/src/9/mpc/devsac.c:363,371
1999/0608		n -= block; if(unsac(buf, data+block, blocksize, n)<0) panic("unsac failed!");
1999/0806		memmove(cache[j].data, buf, blocksize); cache[j].age = cacheage; cache[j].block = block;
1999/0608		} else { memmove(buf, data+block, blocksize); }
1999/0806/sys/src/9/mpc/devsac.c:18,23 – 1999/0807/sys/src/9/mpc/devsac.c:18,24 (short | long)
1999/0608		OPERM = 0x3, /* mask of all permission types in open mode */ Nram = 512,
1999/0806		CacheSize = 20,
1999/0807		OffsetSize = 4, /* size in bytes of an offset */
1999/0608		}; typedef struct SacPath SacPath;
1999/0806/sys/src/9/mpc/devsac.c:62,69 – 1999/0807/sys/src/9/mpc/devsac.c:63,71
1999/0608		{ Ref; SacPath *up; vlong blocks;
1999/0807		long blocks;
1999/0608		int entry;
1999/0807		int nentry;
1999/0608		};
1999/0806		struct Cache
1999/0806/sys/src/9/mpc/devsac.c:91,97 – 1999/0807/sys/src/9/mpc/devsac.c:93,98
1999/0608
1999/0609		static void sacdir(Chan *, SacDir*, char*); static ulong getl(void *p); static vlong getv(void *p); static Sac *saccpy(Sac *s); static Sac *saclookup(Sac *s, char *name); static int sacdirread(Chan *, char *p, long off, long cnt);
1999/0806/sys/src/9/mpc/devsac.c:199,211 – 1999/0807/sys/src/9/mpc/devsac.c:200,213
1999/0608
1999/0609		static long sacread(Chan *c, void *a, long n, vlong off)
1999/0807		sacread(Chan *c, void *a, long n, vlong voff)
1999/0608		{ Sac *sac; char *buf, *buf2;
1999/0609		int nn, cnt, i, j;
1999/0608		uchar *blocks; vlong length;
1999/0807		long length; long off = voff;
1999/0608
1999/0609		buf = a; cnt = n;
1999/0806/sys/src/9/mpc/devsac.c:216,223 – 1999/0807/sys/src/9/mpc/devsac.c:218,224
1999/0609		return sacdirread(c, buf, off, cnt);
1999/0608		}
1999/0609		sac = c->aux;
1999/0610		//print("sacread: %s %llx %d\n", sac->name, off, n);
1999/0608		length = getv(sac->length);
1999/0807		length = getl(sac->length);
1999/0609		if(off >= length)
1999/0608		return 0; if(cnt > length-off)
1999/0806/sys/src/9/mpc/devsac.c:225,237 – 1999/0807/sys/src/9/mpc/devsac.c:226,241
1999/0608		if(cnt == 0) return 0;
1999/0609		n = cnt;
1999/0608		blocks = data + getv(sac->blocks);
1999/0807		blocks = data + getl(sac->blocks);
1999/0608		buf2 = malloc(blocksize); while(cnt > 0) { i = off/blocksize; loadblock(buf2, blocks+i*8, blocksize);
1999/0807		nn = blocksize; if(nn > length-i*blocksize) nn = length-i*blocksize; loadblock(buf2, blocks+i*OffsetSize, nn);
1999/0608		j = off-i*blocksize;
1999/0609		nn = blocksize-j;
1999/0807		nn -= j;
1999/0609		if(nn > cnt) nn = cnt; memmove(buf, buf2+j, nn);
1999/0806/sys/src/9/mpc/devsac.c:278,289 – 1999/0807/sys/src/9/mpc/devsac.c:282,294
1999/0608		}
1999/0609		static SacPath *
1999/0608		sacpathalloc(SacPath *p, vlong blocks, int entry)
1999/0807		sacpathalloc(SacPath *p, long blocks, int entry, int nentry)
1999/0608		{ SacPath *pp = malloc(sizeof(SacPath)); pp->ref = 1; pp->blocks = blocks; pp->entry = entry;
1999/0807		pp->nentry = nentry;
1999/0608		pp->up = p; return pp; }
1999/0806/sys/src/9/mpc/devsac.c:315,325 – 1999/0807/sys/src/9/mpc/devsac.c:320,330
1999/0608		memmove(dir.name, s->name, NAMELEN); dir.qid = (Qid){getl(s->qid), 0}; dir.mode = getl(s->mode); dir.length = getv(s->length);
1999/0807		dir.length = getl(s->length);
1999/0608		if(dir.mode &CHDIR) dir.length *= DIRLEN; strcpy(dir.uid, s->uid); strcpy(dir.gid, s->gid);
1999/0807		memmove(dir.uid, s->uid, NAMELEN); memmove(dir.gid, s->gid, NAMELEN);
1999/0608		dir.atime = getl(s->atime); dir.mtime = getl(s->mtime);
1999/0609		dir.type = devtab[c->type]->dc;
1999/0806/sys/src/9/mpc/devsac.c:330,340 – 1999/0807/sys/src/9/mpc/devsac.c:335,345
1999/0609		static void
1999/0608		loadblock(void *buf, uchar *offset, int blocksize) { vlong block, n;
1999/0807		long block, n;
1999/0806		ulong age; int i, j;
1999/0608		block = getv(offset);
1999/0807		block = getl(offset);
1999/0608		if(block < 0) { block = -block;
1999/0806		cacheage++;
1999/0806/sys/src/9/mpc/devsac.c:357,363 – 1999/0807/sys/src/9/mpc/devsac.c:362,368
1999/0806		return; }
1999/0608		n = getv(offset+8);
1999/0807		n = getl(offset+OffsetSize);
1999/0608		if(n < 0) n = -n; n -= block;
1999/0806/sys/src/9/mpc/devsac.c:376,382 – 1999/0807/sys/src/9/mpc/devsac.c:381,387
1999/0608		{ uchar *blocks; SacDir *buf; int per, i;
1999/0807		int per, i, n;
1999/0608		SacPath *p; p = s->path;
1999/0806/sys/src/9/mpc/devsac.c:390,397 – 1999/0807/sys/src/9/mpc/devsac.c:395,405
1999/0608		blocks = data + p->blocks; per = blocksize/sizeof(SacDir); i = p->entry/per;
1999/0807		n = per; if(n > p->nentry-i*per) n = p->nentry-i*per;
1999/0608		buf = malloc(per*sizeof(SacDir)); loadblock(buf, blocks + i*8, per*sizeof(SacDir));
1999/0807		loadblock(buf, blocks + i*OffsetSize, n*sizeof(SacDir));
1999/0608		s->SacDir = buf[p->entry-i*per]; free(buf); incref(p);
1999/0806/sys/src/9/mpc/devsac.c:405,417 – 1999/0807/sys/src/9/mpc/devsac.c:413,425
1999/0608		{ uchar *blocks; SacDir *buf; int iblock, per, i, j, ndir;
1999/0807		int iblock, per, i, j, n, ndir;
1999/0609		Sac *s;
1999/0608
1999/0609		s = c->aux;
1999/0608		blocks = data + getv(s->blocks);
1999/0807		blocks = data + getl(s->blocks);
1999/0608		per = blocksize/sizeof(SacDir); ndir = getv(s->length);
1999/0807		ndir = getl(s->length);
1999/0608		off /= DIRLEN; cnt /= DIRLEN; if(off >= ndir)
1999/0806/sys/src/9/mpc/devsac.c:423,429 – 1999/0807/sys/src/9/mpc/devsac.c:431,440
1999/0608		for(i=off; i<off+cnt; i++) { j = i/per; if(j != iblock) { loadblock(buf, blocks + j*8, per*sizeof(SacDir));
1999/0807		n = per; if(n > ndir-j*per) n = ndir-j*per; loadblock(buf, blocks + j*OffsetSize, n*sizeof(SacDir));
1999/0608		iblock = j; } j *= per;
1999/0806/sys/src/9/mpc/devsac.c:438,444 – 1999/0807/sys/src/9/mpc/devsac.c:449,455
1999/0608		saclookup(Sac *s, char *name) { int ndir;
1999/0609		int i, j, k, per;
1999/0807		int i, j, k, n, per;
1999/0608		uchar *blocks; SacDir *buf; int iblock;
1999/0806/sys/src/9/mpc/devsac.c:446,454 – 1999/0807/sys/src/9/mpc/devsac.c:457,465
1999/0608		if(strcmp(name, "..") == 0) return sacparent(s); blocks = data + getv(s->blocks);
1999/0807		blocks = data + getl(s->blocks);
1999/0608		per = blocksize/sizeof(SacDir); ndir = getv(s->length);
1999/0807		ndir = getl(s->length);
1999/0608		buf = malloc(per*sizeof(SacDir)); iblock = -1;
1999/0806/sys/src/9/mpc/devsac.c:456,462 – 1999/0807/sys/src/9/mpc/devsac.c:467,476
1999/0609		for(i=0; i<ndir; i++) {
1999/0608		j = i/per; if(j != iblock) { loadblock(buf, blocks + j*8, per*sizeof(SacDir));
1999/0807		n = per; if(n > ndir-j*per) n = ndir-j*per; loadblock(buf, blocks + j*OffsetSize, n*sizeof(SacDir));
1999/0608		iblock = j; } j *= per;
1999/0806/sys/src/9/mpc/devsac.c:463,469 – 1999/0807/sys/src/9/mpc/devsac.c:477,483
1999/0608		sd = buf+i-j; k = strcmp(name, sd->name); if(k == 0) {
1999/0609		s->path = sacpathalloc(s->path, getv(s->blocks), i);
1999/0807		s->path = sacpathalloc(s->path, getl(s->blocks), i, ndir);
1999/0608		s->SacDir = *sd; free(buf);
1999/0609		return s;
1999/0806/sys/src/9/mpc/devsac.c:479,501 – 1999/0807/sys/src/9/mpc/devsac.c:493,498
1999/0608		uchar *a = p; return (a[0]<<24) | (a[1]<<16) | (a[2]<<8) | a[3]; }
1999/0609		static vlong
1999/0608		getv(void *p) { uchar *a = p; ulong l0, l1; vlong v;                  l0 = (a[0]<<24) | (a[1]<<16) | (a[2]<<8) | a[3]; a += 4; l1 = (a[0]<<24) | (a[1]<<16) | (a[2]<<8) | a[3];                  v = l0; v <<= 32; v |= l1; return v; } Dev sacdevtab = {
1999/0807/sys/src/9/mpc/devsac.c:162,167 – 1999/1231/sys/src/9/mpc/devsac.c:162,169 (short | long)
1999/0608		isdir(c);
1999/0609		if(name[0]=='.' && name[1]==0)
1999/0608		return 1;
1999/1231		if(name[0]=='.' && name[1]=='.' && name[2]==0) return 1;
1999/0609		sac = c->aux;
1999/0608		sac = saclookup(sac, name); if(sac == nil) {
1999/1231/sys/src/9/mpc/devsac.c:6,18 – 2000/0516/sys/src/9/mpc/devsac.c:6,11 (short | long)
1999/0608		#include "io.h"
1999/0609		#include "../port/error.h"
1999/0608		/* * Rather than reading /adm/users, which is a lot of work for * a toy program, we assume all groups have the form * NNN:user:user: * meaning that each user is the leader of his own group. */                  enum { OPERM = 0x3, /* mask of all permission types in open mode */
1999/1231/sys/src/9/mpc/devsac.c:85,91 – 2000/0516/sys/src/9/mpc/devsac.c:78,85
1999/0608		Powner = 64, };
1999/0609		static uchar *data = SACMEM;
2000/0516		static char *sacfs = "fs.sac"; static uchar *data;
1999/0609		static int blocksize; static Sac root;
1999/0806		static Cache cache[CacheSize];
1999/1231/sys/src/9/mpc/devsac.c:104,112 – 2000/0516/sys/src/9/mpc/devsac.c:98,123
1999/0608		{ SacHeader *hdr;
1999/0806		uchar *p;
2000/0516		char *s;
1999/0806		int i;
1999/0609		print("sacinit\n");
2000/0516		s = getconf("flash"); if(s == nil) { print("devsac: no flash file system\n"); return; } p = (uchar*)strtoul(s, 0, 0); if(p == 0) { print("devsac: bad address for flash file system\n"); return; } data = tarlookup(p, sacfs, &i); if(data == 0) { print("devsac: could not find file: %s\n", sacfs); return; }
1999/0608		hdr = (SacHeader*)data; if(getl(hdr->magic) != Magic) {
1999/0609		print("devsac: bad magic\n");
2000/0516/sys/src/9/mpc/devsac.c:173,180 – 2000/1208/sys/src/9/mpc/devsac.c:173,178 (short | long)
1999/0608		isdir(c);
1999/0609		if(name[0]=='.' && name[1]==0)
1999/0608		return 1;
1999/1231		if(name[0]=='.' && name[1]=='.' && name[2]==0) return 1;
1999/0609		sac = c->aux;
1999/0608		sac = saclookup(sac, name); if(sac == nil) {
2000/1208/sys/src/9/mpc/devsac.c:1,528 – 2001/0527/sys/src/9/mpc/devsac.c:0 (short | long)
Deleted. rsc Mon Mar 7 10:28:39 2005
1999/0608		#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h"
1999/0609		#include "../port/error.h"
1999/0608		enum { OPERM = 0x3, /* mask of all permission types in open mode */ Nram = 512,
1999/0806		CacheSize = 20,
1999/0807		OffsetSize = 4, /* size in bytes of an offset */
1999/0608		};                  typedef struct SacPath SacPath; typedef struct Sac Sac; typedef struct SacHeader SacHeader; typedef struct SacDir SacDir;
1999/0806		typedef struct Cache Cache;
1999/0608		enum { Magic = 0x5acf5, };                  struct SacDir { char name[NAMELEN]; char uid[NAMELEN]; char gid[NAMELEN]; uchar qid[4]; uchar mode[4]; uchar atime[4]; uchar mtime[4]; uchar length[8]; uchar blocks[8]; };                  struct SacHeader { uchar magic[4]; uchar length[8]; uchar blocksize[4]; uchar md5[16]; };                                   struct Sac { SacDir; SacPath *path; };                  struct SacPath { Ref; SacPath *up;
1999/0807		long blocks;
1999/0608		int entry;
1999/0807		int nentry;
1999/0608		};
1999/0806		struct Cache { long block; ulong age; uchar *data; };
1999/0608		enum { Pexec = 1, Pwrite = 2, Pread = 4, Pother = 1, Pgroup = 8, Powner = 64, };
2000/0516		static char *sacfs = "fs.sac"; static uchar *data;
1999/0609		static int blocksize; static Sac root;
1999/0806		static Cache cache[CacheSize]; static ulong cacheage;
1999/0608
1999/0609		static void sacdir(Chan *, SacDir*, char*); static ulong getl(void *p); static Sac *saccpy(Sac *s); static Sac *saclookup(Sac *s, char *name); static int sacdirread(Chan *, char *p, long off, long cnt); static void loadblock(void *buf, uchar *offset, int blocksize); static void sacfree(Sac*);
1999/0608
1999/0609		static void sacinit(void)
1999/0608		{ SacHeader *hdr;
1999/0806		uchar *p;
2000/0516		char *s;
1999/0806		int i;
1999/0609		print("sacinit\n");
2000/0516		s = getconf("flash"); if(s == nil) { print("devsac: no flash file system\n"); return; }                  p = (uchar*)strtoul(s, 0, 0); if(p == 0) { print("devsac: bad address for flash file system\n"); return; } data = tarlookup(p, sacfs, &i); if(data == 0) { print("devsac: could not find file: %s\n", sacfs); return; }
1999/0608		hdr = (SacHeader*)data; if(getl(hdr->magic) != Magic) {
1999/0609		print("devsac: bad magic\n");
1999/0608		return; } blocksize = getl(hdr->blocksize); root.SacDir = *(SacDir*)(data + sizeof(SacHeader));
1999/0806		p = malloc(CacheSize*blocksize); if(p == nil) error("allocating cache"); for(i=0; i<CacheSize; i++) { cache[i].data = p; p += blocksize; }
1999/0608		}                  static Chan* sacattach(char* spec) { Chan *c; int dev;                  dev = atoi(spec); if(dev != 0) error("bad specification");                  // check if init found sac file system in memory if(blocksize == 0) error("devsac: bad magic");                  c = devattach('C', spec); c->qid = (Qid){getl(root.qid), 0}; c->dev = dev; c->aux = saccpy(&root); return c; }
1999/0609		static Chan*
1999/0608		sacclone(Chan *c, Chan *nc) { nc = devclone(c, nc); nc->aux = saccpy(c->aux); return nc; }
1999/0609		static int sacwalk(Chan *c, char *name)
1999/0608		{ Sac *sac;
1999/0610		//print("walk %s\n", name);
1999/0608		isdir(c);
1999/0609		if(name[0]=='.' && name[1]==0)
1999/0608		return 1;
1999/0609		sac = c->aux;
1999/0608		sac = saclookup(sac, name); if(sac == nil) { strncpy(up->error, Enonexist, NAMELEN); return 0; } c->aux = sac; c->qid = (Qid){getl(sac->qid), 0}; return 1; }
1999/0609		static Chan* sacopen(Chan *c, int omode)
1999/0608		{
1999/0609		ulong t, mode; Sac *sac; static int access[] = { 0400, 0200, 0600, 0100 };
1999/0608
1999/0609		sac = c->aux; mode = getl(sac->mode); if(strcmp(up->user, sac->uid) == 0) mode = mode; else if(strcmp(up->user, sac->gid) == 0) mode = mode<<3; else mode = mode<<6;
1999/0608
1999/0609		t = access[omode&3]; if((t & mode) != t) error(Eperm); c->offset = 0; c->mode = openmode(omode); c->flag |= COPEN; return c;
1999/0608		}
1999/0609		static long
1999/0807		sacread(Chan *c, void *a, long n, vlong voff)
1999/0608		{ Sac *sac; char *buf, *buf2;
1999/0609		int nn, cnt, i, j;
1999/0608		uchar *blocks;
1999/0807		long length; long off = voff;
1999/0608
1999/0609		buf = a; cnt = n; if(c->qid.path & CHDIR){ cnt = (cnt/DIRLEN)*DIRLEN;
1999/0608		if(off%DIRLEN)
1999/0609		error("i/o error"); return sacdirread(c, buf, off, cnt);
1999/0608		}
1999/0609		sac = c->aux;
1999/0807		length = getl(sac->length);
1999/0609		if(off >= length)
1999/0608		return 0; if(cnt > length-off) cnt = length-off; if(cnt == 0) return 0;
1999/0609		n = cnt;
1999/0807		blocks = data + getl(sac->blocks);
1999/0608		buf2 = malloc(blocksize); while(cnt > 0) { i = off/blocksize;
1999/0807		nn = blocksize; if(nn > length-i*blocksize) nn = length-i*blocksize; loadblock(buf2, blocks+i*OffsetSize, nn);
1999/0608		j = off-i*blocksize;
1999/0807		nn -= j;
1999/0609		if(nn > cnt) nn = cnt; memmove(buf, buf2+j, nn); cnt -= nn; off += nn;
1999/0610		buf += nn;
1999/0608		} free(buf2);
1999/0609		return n;
1999/0608		}
1999/0609		static long sacwrite(Chan *, void *, long, vlong)
1999/0608		{
1999/0609		error(Eperm);
1999/0608		return 0; }
1999/0609		static void sacclose(Chan* c)
1999/0608		{
1999/0609		Sac *sac = c->aux; c->aux = nil; sacfree(sac);
1999/0608		}
1999/0609		static void sacstat(Chan *c, char *db)
1999/0608		{
1999/0609		sacdir(c, c->aux, db);
1999/0608		}
1999/0609		static Sac*
1999/0608		saccpy(Sac *s) { Sac *ss;                  ss = malloc(sizeof(Sac)); *ss = *s; if(ss->path) incref(ss->path); return ss; }
1999/0609		static SacPath *
1999/0807		sacpathalloc(SacPath *p, long blocks, int entry, int nentry)
1999/0608		{ SacPath *pp = malloc(sizeof(SacPath)); pp->ref = 1; pp->blocks = blocks; pp->entry = entry;
1999/0807		pp->nentry = nentry;
1999/0608		pp->up = p; return pp; }                  static void sacpathfree(SacPath *p) { if(p == nil) return; if(decref(p) > 0) return; sacpathfree(p->up); free(p); }
1999/0609		static void
1999/0608		sacfree(Sac *s) { sacpathfree(s->path); free(s); }
1999/0609		static void sacdir(Chan *c, SacDir *s, char *buf)
1999/0608		{ Dir dir;                  memmove(dir.name, s->name, NAMELEN); dir.qid = (Qid){getl(s->qid), 0}; dir.mode = getl(s->mode);
1999/0807		dir.length = getl(s->length);
1999/0608		if(dir.mode &CHDIR) dir.length *= DIRLEN;
1999/0807		memmove(dir.uid, s->uid, NAMELEN); memmove(dir.gid, s->gid, NAMELEN);
1999/0608		dir.atime = getl(s->atime); dir.mtime = getl(s->mtime);
1999/0609		dir.type = devtab[c->type]->dc; dir.dev = c->dev;
1999/0608		convD2M(&dir, buf); }
1999/0609		static void
1999/0608		loadblock(void *buf, uchar *offset, int blocksize) {
1999/0807		long block, n;
1999/0806		ulong age; int i, j;
1999/0608
1999/0807		block = getl(offset);
1999/0608		if(block < 0) { block = -block;
1999/0806		cacheage++; // age has wraped if(cacheage == 0) { for(i=0; i<CacheSize; i++) cache[i].age = 0; } j = 0; age = cache[0].age; for(i=0; i<CacheSize; i++) { if(cache[i].age < age) { age = cache[i].age; j = i; } if(cache[i].block != block) continue; memmove(buf, cache[i].data, blocksize); cache[i].age = cacheage; return; }
1999/0807		n = getl(offset+OffsetSize);
1999/0608		if(n < 0) n = -n; n -= block; if(unsac(buf, data+block, blocksize, n)<0) panic("unsac failed!");
1999/0806		memmove(cache[j].data, buf, blocksize); cache[j].age = cacheage; cache[j].block = block;
1999/0608		} else { memmove(buf, data+block, blocksize); } }
1999/0609		static Sac*
1999/0608		sacparent(Sac *s) { uchar *blocks; SacDir *buf;
1999/0807		int per, i, n;
1999/0608		SacPath *p;                  p = s->path; if(p == nil || p->up == nil) {
1999/0609		sacpathfree(p);
1999/0608		*s = root; return s; } p = p->up;                  blocks = data + p->blocks; per = blocksize/sizeof(SacDir); i = p->entry/per;
1999/0807		n = per; if(n > p->nentry-i*per) n = p->nentry-i*per;
1999/0608		buf = malloc(per*sizeof(SacDir));
1999/0807		loadblock(buf, blocks + i*OffsetSize, n*sizeof(SacDir));
1999/0608		s->SacDir = buf[p->entry-i*per]; free(buf); incref(p);
1999/0609		sacpathfree(s->path);
1999/0608		s->path = p; return s; }
1999/0609		static int sacdirread(Chan *c, char *p, long off, long cnt)
1999/0608		{ uchar *blocks; SacDir *buf;
1999/0807		int iblock, per, i, j, n, ndir;
1999/0609		Sac *s;
1999/0608
1999/0609		s = c->aux;
1999/0807		blocks = data + getl(s->blocks);
1999/0608		per = blocksize/sizeof(SacDir);
1999/0807		ndir = getl(s->length);
1999/0608		off /= DIRLEN; cnt /= DIRLEN; if(off >= ndir) return 0; if(cnt > ndir-off) cnt = ndir-off; iblock = -1; buf = malloc(per*sizeof(SacDir)); for(i=off; i<off+cnt; i++) { j = i/per; if(j != iblock) {
1999/0807		n = per; if(n > ndir-j*per) n = ndir-j*per; loadblock(buf, blocks + j*OffsetSize, n*sizeof(SacDir));
1999/0608		iblock = j; } j *= per;
1999/0609		sacdir(c, buf+i-j, p);
1999/0608		p += DIRLEN; } free(buf); return cnt*DIRLEN; }
1999/0609		static Sac*
1999/0608		saclookup(Sac *s, char *name) { int ndir;
1999/0807		int i, j, k, n, per;
1999/0608		uchar *blocks; SacDir *buf; int iblock; SacDir *sd;                  if(strcmp(name, "..") == 0) return sacparent(s);
1999/0807		blocks = data + getl(s->blocks);
1999/0608		per = blocksize/sizeof(SacDir);
1999/0807		ndir = getl(s->length);
1999/0608		buf = malloc(per*sizeof(SacDir)); iblock = -1;
1999/0609		// linear search for(i=0; i<ndir; i++) {
1999/0608		j = i/per; if(j != iblock) {
1999/0807		n = per; if(n > ndir-j*per) n = ndir-j*per; loadblock(buf, blocks + j*OffsetSize, n*sizeof(SacDir));
1999/0608		iblock = j; } j *= per; sd = buf+i-j; k = strcmp(name, sd->name); if(k == 0) {
1999/0807		s->path = sacpathalloc(s->path, getl(s->blocks), i, ndir);
1999/0608		s->SacDir = *sd; free(buf);
1999/0609		return s;
1999/0608		} }
1999/0609		free(buf);
1999/0608		return 0; }
1999/0609		static ulong
1999/0608		getl(void *p) { uchar *a = p;                  return (a[0]<<24) | (a[1]<<16) | (a[2]<<8) | a[3]; }                  Dev sacdevtab = { 'C', "sac",                  devreset, sacinit, sacattach, sacclone, sacwalk, sacstat, sacopen, devcreate, sacclose, sacread, devbread, sacwrite, devbwrite, devremove, devwstat, };