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 struct Ndbcache
  7 d957951b 2005-02-11 devnull {
  8 d957951b 2005-02-11 devnull 	Ndbcache	*next;
  9 d957951b 2005-02-11 devnull 	char		*attr;
 10 d957951b 2005-02-11 devnull 	char		*val;
 11 d957951b 2005-02-11 devnull 	Ndbs		s;
 12 fa325e9b 2020-01-10 cross 	Ndbtuple	*t;
 13 d957951b 2005-02-11 devnull };
 14 d957951b 2005-02-11 devnull 
 15 d957951b 2005-02-11 devnull enum
 16 d957951b 2005-02-11 devnull {
 17 cbeb0b26 2006-04-01 devnull 	Maxcached=	128
 18 d957951b 2005-02-11 devnull };
 19 d957951b 2005-02-11 devnull 
 20 d957951b 2005-02-11 devnull static void
 21 d957951b 2005-02-11 devnull ndbcachefree(Ndbcache *c)
 22 d957951b 2005-02-11 devnull {
 23 d957951b 2005-02-11 devnull 	free(c->val);
 24 d957951b 2005-02-11 devnull 	free(c->attr);
 25 d957951b 2005-02-11 devnull 	if(c->t)
 26 d957951b 2005-02-11 devnull 		ndbfree(c->t);
 27 d957951b 2005-02-11 devnull 	free(c);
 28 d957951b 2005-02-11 devnull }
 29 d957951b 2005-02-11 devnull 
 30 d957951b 2005-02-11 devnull static Ndbtuple*
 31 d957951b 2005-02-11 devnull ndbcopy(Ndb *db, Ndbtuple *from_t, Ndbs *from_s, Ndbs *to_s)
 32 d957951b 2005-02-11 devnull {
 33 d957951b 2005-02-11 devnull 	Ndbtuple *first, *to_t, *last, *line;
 34 d957951b 2005-02-11 devnull 	int newline;
 35 d957951b 2005-02-11 devnull 
 36 d957951b 2005-02-11 devnull 	*to_s = *from_s;
 37 d957951b 2005-02-11 devnull 	to_s->t = nil;
 38 d957951b 2005-02-11 devnull 	to_s->db = db;
 39 d957951b 2005-02-11 devnull 
 40 d957951b 2005-02-11 devnull 	newline = 1;
 41 d957951b 2005-02-11 devnull 	last = nil;
 42 d957951b 2005-02-11 devnull 	first = nil;
 43 d957951b 2005-02-11 devnull 	line = nil;
 44 d957951b 2005-02-11 devnull 	for(; from_t != nil; from_t = from_t->entry){
 45 d957951b 2005-02-11 devnull 		to_t = ndbnew(from_t->attr, from_t->val);
 46 d957951b 2005-02-11 devnull 
 47 d957951b 2005-02-11 devnull 		/* have s point to matching tuple */
 48 d957951b 2005-02-11 devnull 		if(from_s->t == from_t)
 49 d957951b 2005-02-11 devnull 			to_s->t = to_t;
 50 d957951b 2005-02-11 devnull 
 51 d957951b 2005-02-11 devnull 		if(newline)
 52 d957951b 2005-02-11 devnull 			line = to_t;
 53 d957951b 2005-02-11 devnull 		else
 54 d957951b 2005-02-11 devnull 			last->line = to_t;
 55 d957951b 2005-02-11 devnull 
 56 d957951b 2005-02-11 devnull 		if(last != nil)
 57 d957951b 2005-02-11 devnull 			last->entry = to_t;
 58 d957951b 2005-02-11 devnull 		else {
 59 d957951b 2005-02-11 devnull 			first = to_t;
 60 d957951b 2005-02-11 devnull 			line = to_t;
 61 d957951b 2005-02-11 devnull 		}
 62 d957951b 2005-02-11 devnull 		to_t->entry = nil;
 63 d957951b 2005-02-11 devnull 		to_t->line = line;
 64 d957951b 2005-02-11 devnull 		last = to_t;
 65 d957951b 2005-02-11 devnull 		newline = from_t->line != from_t->entry;
 66 d957951b 2005-02-11 devnull 	}
 67 d957951b 2005-02-11 devnull 	return first;
 68 d957951b 2005-02-11 devnull }
 69 d957951b 2005-02-11 devnull 
 70 d957951b 2005-02-11 devnull /*
 71 d957951b 2005-02-11 devnull  *  if found, move to front
 72 d957951b 2005-02-11 devnull  */
 73 d957951b 2005-02-11 devnull int
 74 d957951b 2005-02-11 devnull _ndbcachesearch(Ndb *db, Ndbs *s, char *attr, char *val, Ndbtuple **t)
 75 d957951b 2005-02-11 devnull {
 76 d957951b 2005-02-11 devnull 	Ndbcache *c, **l;
 77 d957951b 2005-02-11 devnull 
 78 d957951b 2005-02-11 devnull 	*t = nil;
 79 d957951b 2005-02-11 devnull 	c = nil;
 80 d957951b 2005-02-11 devnull 	for(l = &db->cache; *l != nil; l = &(*l)->next){
 81 d957951b 2005-02-11 devnull 		c = *l;
 82 d957951b 2005-02-11 devnull 		if(strcmp(c->attr, attr) == 0 && strcmp(c->val, val) == 0)
 83 d957951b 2005-02-11 devnull 			break;
 84 d957951b 2005-02-11 devnull 	}
 85 d957951b 2005-02-11 devnull 	if(*l == nil)
 86 d957951b 2005-02-11 devnull 		return -1;
 87 d957951b 2005-02-11 devnull 
 88 d957951b 2005-02-11 devnull 	/* move to front */
 89 d957951b 2005-02-11 devnull 	*l = c->next;
 90 d957951b 2005-02-11 devnull 	c->next = db->cache;
 91 d957951b 2005-02-11 devnull 	db->cache = c;
 92 d957951b 2005-02-11 devnull 
 93 d957951b 2005-02-11 devnull 	*t = ndbcopy(db, c->t, &c->s, s);
 94 d957951b 2005-02-11 devnull 	return 0;
 95 d957951b 2005-02-11 devnull }
 96 d957951b 2005-02-11 devnull 
 97 d957951b 2005-02-11 devnull Ndbtuple*
 98 d957951b 2005-02-11 devnull _ndbcacheadd(Ndb *db, Ndbs *s, char *attr, char *val, Ndbtuple *t)
 99 d957951b 2005-02-11 devnull {
100 d957951b 2005-02-11 devnull 	Ndbcache *c, **l;
101 d957951b 2005-02-11 devnull 
102 d957951b 2005-02-11 devnull 	c = mallocz(sizeof *c, 1);
103 d957951b 2005-02-11 devnull 	if(c == nil)
104 d957951b 2005-02-11 devnull 		return nil;
105 d957951b 2005-02-11 devnull 	c->attr = strdup(attr);
106 d957951b 2005-02-11 devnull 	if(c->attr == nil)
107 d957951b 2005-02-11 devnull 		goto err;
108 d957951b 2005-02-11 devnull 	c->val = strdup(val);
109 d957951b 2005-02-11 devnull 	if(c->val == nil)
110 d957951b 2005-02-11 devnull 		goto err;
111 d957951b 2005-02-11 devnull 	c->t = ndbcopy(db, t, s, &c->s);
112 d957951b 2005-02-11 devnull 	if(c->t == nil && t != nil)
113 d957951b 2005-02-11 devnull 		goto err;
114 d957951b 2005-02-11 devnull 
115 d957951b 2005-02-11 devnull 	/* add to front */
116 d957951b 2005-02-11 devnull 	c->next = db->cache;
117 d957951b 2005-02-11 devnull 	db->cache = c;
118 d957951b 2005-02-11 devnull 
119 d957951b 2005-02-11 devnull 	/* trim list */
120 d957951b 2005-02-11 devnull 	if(db->ncache < Maxcached){
121 d957951b 2005-02-11 devnull 		db->ncache++;
122 d957951b 2005-02-11 devnull 		return t;
123 d957951b 2005-02-11 devnull 	}
124 d957951b 2005-02-11 devnull 	for(l = &db->cache; (*l)->next; l = &(*l)->next)
125 d957951b 2005-02-11 devnull 		;
126 d957951b 2005-02-11 devnull 	c = *l;
127 d957951b 2005-02-11 devnull 	*l = nil;
128 d957951b 2005-02-11 devnull err:
129 d957951b 2005-02-11 devnull 	ndbcachefree(c);
130 d957951b 2005-02-11 devnull 	return t;
131 d957951b 2005-02-11 devnull }
132 d957951b 2005-02-11 devnull 
133 d957951b 2005-02-11 devnull void
134 d957951b 2005-02-11 devnull _ndbcacheflush(Ndb *db)
135 d957951b 2005-02-11 devnull {
136 d957951b 2005-02-11 devnull 	Ndbcache *c;
137 d957951b 2005-02-11 devnull 
138 d957951b 2005-02-11 devnull 	while(db->cache != nil){
139 d957951b 2005-02-11 devnull 		c = db->cache;
140 d957951b 2005-02-11 devnull 		db->cache = c->next;
141 d957951b 2005-02-11 devnull 		ndbcachefree(c);
142 d957951b 2005-02-11 devnull 	}
143 d957951b 2005-02-11 devnull 	db->ncache = 0;
144 d957951b 2005-02-11 devnull }