1 d957951b 2005-02-11 devnull #include <u.h>
  2 d957951b 2005-02-11 devnull #include <libc.h>
  3 d957951b 2005-02-11 devnull #include <bio.h>
  4 d957951b 2005-02-11 devnull #include <ndb.h>
  5 d957951b 2005-02-11 devnull 
  6 d957951b 2005-02-11 devnull /*
  7 d957951b 2005-02-11 devnull  *  make the hash table completely in memory and then write as a file
  8 d957951b 2005-02-11 devnull  */
  9 d957951b 2005-02-11 devnull 
 10 d957951b 2005-02-11 devnull uchar *ht;
 11 d957951b 2005-02-11 devnull ulong hlen;
 12 d957951b 2005-02-11 devnull Ndb *db;
 13 d957951b 2005-02-11 devnull ulong nextchain;
 14 d957951b 2005-02-11 devnull 
 15 d957951b 2005-02-11 devnull char*
 16 d957951b 2005-02-11 devnull syserr(void)
 17 d957951b 2005-02-11 devnull {
 18 d957951b 2005-02-11 devnull 	static char buf[ERRMAX];
 19 d957951b 2005-02-11 devnull 
 20 d957951b 2005-02-11 devnull 	errstr(buf, sizeof buf);
 21 d957951b 2005-02-11 devnull 	return buf;
 22 d957951b 2005-02-11 devnull }
 23 d957951b 2005-02-11 devnull 
 24 d957951b 2005-02-11 devnull void
 25 d957951b 2005-02-11 devnull enter(char *val, ulong dboff)
 26 d957951b 2005-02-11 devnull {
 27 d957951b 2005-02-11 devnull 	ulong h;
 28 d957951b 2005-02-11 devnull 	uchar *last;
 29 d957951b 2005-02-11 devnull 	ulong ptr;
 30 d957951b 2005-02-11 devnull 
 31 d957951b 2005-02-11 devnull 	h = ndbhash(val, hlen);
 32 d957951b 2005-02-11 devnull 	h *= NDBPLEN;
 33 d957951b 2005-02-11 devnull 	last = &ht[h];
 34 d957951b 2005-02-11 devnull 	ptr = NDBGETP(last);
 35 d957951b 2005-02-11 devnull 	if(ptr == NDBNAP){
 36 d957951b 2005-02-11 devnull 		NDBPUTP(dboff, last);
 37 d957951b 2005-02-11 devnull 		return;
 38 d957951b 2005-02-11 devnull 	}
 39 d957951b 2005-02-11 devnull 
 40 d957951b 2005-02-11 devnull 	if(ptr & NDBCHAIN){
 41 d957951b 2005-02-11 devnull 		/* walk the chain to the last entry */
 42 d957951b 2005-02-11 devnull 		for(;;){
 43 d957951b 2005-02-11 devnull 			ptr &= ~NDBCHAIN;
 44 d957951b 2005-02-11 devnull 			last = &ht[ptr+NDBPLEN];
 45 d957951b 2005-02-11 devnull 			ptr = NDBGETP(last);
 46 d957951b 2005-02-11 devnull 			if(ptr == NDBNAP){
 47 d957951b 2005-02-11 devnull 				NDBPUTP(dboff, last);
 48 d957951b 2005-02-11 devnull 				return;
 49 d957951b 2005-02-11 devnull 			}
 50 d957951b 2005-02-11 devnull 			if(!(ptr & NDBCHAIN)){
 51 d957951b 2005-02-11 devnull 				NDBPUTP(nextchain|NDBCHAIN, last);
 52 d957951b 2005-02-11 devnull 				break;
 53 d957951b 2005-02-11 devnull 			}
 54 d957951b 2005-02-11 devnull 		}
 55 d957951b 2005-02-11 devnull 	} else
 56 d957951b 2005-02-11 devnull 		NDBPUTP(nextchain|NDBCHAIN, last);
 57 d957951b 2005-02-11 devnull 
 58 d957951b 2005-02-11 devnull 	/* add a chained entry */
 59 d957951b 2005-02-11 devnull 	NDBPUTP(ptr, &ht[nextchain]);
 60 d957951b 2005-02-11 devnull 	NDBPUTP(dboff, &ht[nextchain + NDBPLEN]);
 61 d957951b 2005-02-11 devnull 	nextchain += 2*NDBPLEN;
 62 d957951b 2005-02-11 devnull }
 63 d957951b 2005-02-11 devnull 
 64 d957951b 2005-02-11 devnull uchar nbuf[16*1024];
 65 d957951b 2005-02-11 devnull 
 66 d957951b 2005-02-11 devnull void
 67 d957951b 2005-02-11 devnull main(int argc, char **argv)
 68 d957951b 2005-02-11 devnull {
 69 d957951b 2005-02-11 devnull 	Ndbtuple *t, *nt;
 70 d957951b 2005-02-11 devnull 	int n;
 71 fa325e9b 2020-01-10 cross 	Dir *d;
 72 d957951b 2005-02-11 devnull 	uchar buf[8];
 73 d957951b 2005-02-11 devnull 	char file[128];
 74 d957951b 2005-02-11 devnull 	int fd;
 75 d957951b 2005-02-11 devnull 	ulong off;
 76 d957951b 2005-02-11 devnull 	uchar *p;
 77 d957951b 2005-02-11 devnull 
 78 d957951b 2005-02-11 devnull 	if(argc != 3){
 79 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: usage file attribute\n");
 80 d957951b 2005-02-11 devnull 		exits("usage");
 81 d957951b 2005-02-11 devnull 	}
 82 d957951b 2005-02-11 devnull 	db = ndbopen(argv[1]);
 83 d957951b 2005-02-11 devnull 	if(db == 0){
 84 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: can't open %s\n", argv[1]);
 85 d957951b 2005-02-11 devnull 		exits(syserr());
 86 d957951b 2005-02-11 devnull 	}
 87 d957951b 2005-02-11 devnull 
 88 d957951b 2005-02-11 devnull 	/* try a bigger than normal buffer */
 89 d957951b 2005-02-11 devnull 	Binits(&db->b, Bfildes(&db->b), OREAD, nbuf, sizeof(nbuf));
 90 d957951b 2005-02-11 devnull 
 91 d957951b 2005-02-11 devnull 	/* count entries to calculate hash size */
 92 d957951b 2005-02-11 devnull 	n = 0;
 93 d957951b 2005-02-11 devnull 
 94 d957951b 2005-02-11 devnull 	while(nt = ndbparse(db)){
 95 d957951b 2005-02-11 devnull 		for(t = nt; t; t = t->entry){
 96 d957951b 2005-02-11 devnull 			if(strcmp(t->attr, argv[2]) == 0)
 97 d957951b 2005-02-11 devnull 				n++;
 98 d957951b 2005-02-11 devnull 		}
 99 d957951b 2005-02-11 devnull 		ndbfree(nt);
100 d957951b 2005-02-11 devnull 	}
101 d957951b 2005-02-11 devnull 
102 d957951b 2005-02-11 devnull 	/* allocate an array large enough for worst case */
103 d957951b 2005-02-11 devnull 	hlen = 2*n+1;
104 d957951b 2005-02-11 devnull 	n = hlen*NDBPLEN + hlen*2*NDBPLEN;
105 d957951b 2005-02-11 devnull 	ht = mallocz(n, 1);
106 d957951b 2005-02-11 devnull 	if(ht == 0){
107 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: not enough memory\n");
108 d957951b 2005-02-11 devnull 		exits(syserr());
109 d957951b 2005-02-11 devnull 	}
110 d957951b 2005-02-11 devnull 	for(p = ht; p < &ht[n]; p += NDBPLEN)
111 d957951b 2005-02-11 devnull 		NDBPUTP(NDBNAP, p);
112 d957951b 2005-02-11 devnull 	nextchain = hlen*NDBPLEN;
113 d957951b 2005-02-11 devnull 
114 d957951b 2005-02-11 devnull 	/* create the in core hash table */
115 d957951b 2005-02-11 devnull 	Bseek(&db->b, 0, 0);
116 d957951b 2005-02-11 devnull 	off = 0;
117 d957951b 2005-02-11 devnull 	while(nt = ndbparse(db)){
118 d957951b 2005-02-11 devnull 		for(t = nt; t; t = t->entry){
119 d957951b 2005-02-11 devnull 			if(strcmp(t->attr, argv[2]) == 0)
120 d957951b 2005-02-11 devnull 				enter(t->val, off);
121 d957951b 2005-02-11 devnull 		}
122 d957951b 2005-02-11 devnull 		ndbfree(nt);
123 d957951b 2005-02-11 devnull 		off = Boffset(&db->b);
124 d957951b 2005-02-11 devnull 	}
125 d957951b 2005-02-11 devnull 
126 d957951b 2005-02-11 devnull 	/* create the hash file */
127 d957951b 2005-02-11 devnull 	snprint(file, sizeof(file), "%s.%s", argv[1], argv[2]);
128 d957951b 2005-02-11 devnull 	fd = create(file, ORDWR, 0664);
129 d957951b 2005-02-11 devnull 	if(fd < 0){
130 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: can't create %s\n", file);
131 d957951b 2005-02-11 devnull 		exits(syserr());
132 d957951b 2005-02-11 devnull 	}
133 d957951b 2005-02-11 devnull 	NDBPUTUL(db->mtime, buf);
134 d957951b 2005-02-11 devnull 	NDBPUTUL(hlen, buf+NDBULLEN);
135 d957951b 2005-02-11 devnull 	if(write(fd, buf, NDBHLEN) != NDBHLEN){
136 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: writing %s\n", file);
137 d957951b 2005-02-11 devnull 		exits(syserr());
138 d957951b 2005-02-11 devnull 	}
139 d957951b 2005-02-11 devnull 	if(write(fd, ht, nextchain) != nextchain){
140 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: writing %s\n", file);
141 d957951b 2005-02-11 devnull 		exits(syserr());
142 d957951b 2005-02-11 devnull 	}
143 d957951b 2005-02-11 devnull 	close(fd);
144 d957951b 2005-02-11 devnull 
145 d957951b 2005-02-11 devnull 	/* make sure file didn't change while we were making the hash */
146 d957951b 2005-02-11 devnull 	d = dirstat(argv[1]);
147 d957951b 2005-02-11 devnull 	if(d == nil || d->qid.path != db->qid.path
148 d957951b 2005-02-11 devnull 	   || d->qid.vers != db->qid.vers){
149 d957951b 2005-02-11 devnull 		fprint(2, "mkhash: %s changed underfoot\n", argv[1]);
150 d957951b 2005-02-11 devnull 		remove(file);
151 d957951b 2005-02-11 devnull 		exits("changed");
152 d957951b 2005-02-11 devnull 	}
153 d957951b 2005-02-11 devnull 
154 d957951b 2005-02-11 devnull 	exits(0);
155 d957951b 2005-02-11 devnull }