1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include "ndb.h"
5
6 /*
7 * search for a tuple that has the given 'attr=val' and also 'rattr=x'.
8 * copy 'x' into 'buf' and return the whole tuple.
9 *
10 * return 0 if not found.
11 */
12 char*
ndbgetvalue(Ndb * db,Ndbs * s,char * attr,char * val,char * rattr,Ndbtuple ** pp)13 ndbgetvalue(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, Ndbtuple **pp)
14 {
15 Ndbtuple *t, *nt;
16 char *rv;
17 Ndbs temps;
18
19 if(s == nil)
20 s = &temps;
21 if(pp)
22 *pp = nil;
23 t = ndbsearch(db, s, attr, val);
24 while(t){
25 /* first look on same line (closer binding) */
26 nt = s->t;
27 for(;;){
28 if(strcmp(rattr, nt->attr) == 0){
29 rv = strdup(nt->val);
30 if(pp != nil)
31 *pp = t;
32 else
33 ndbfree(t);
34 return rv;
35 }
36 nt = nt->line;
37 if(nt == s->t)
38 break;
39 }
40 /* search whole tuple */
41 for(nt = t; nt; nt = nt->entry){
42 if(strcmp(rattr, nt->attr) == 0){
43 rv = strdup(nt->val);
44 if(pp != nil)
45 *pp = t;
46 else
47 ndbfree(t);
48 return rv;
49 }
50 }
51 ndbfree(t);
52 t = ndbsnext(s, attr, val);
53 }
54 return nil;
55 }
56
57 Ndbtuple*
ndbgetval(Ndb * db,Ndbs * s,char * attr,char * val,char * rattr,char * buf)58 ndbgetval(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, char *buf)
59 {
60 Ndbtuple *t;
61 char *p;
62
63 p = ndbgetvalue(db, s, attr, val, rattr, &t);
64 if(p == nil){
65 if(buf != nil)
66 *buf = 0;
67 } else {
68 if(buf != nil){
69 strncpy(buf, p, Ndbvlen-1);
70 buf[Ndbvlen-1] = 0;
71 }
72 free(p);
73 }
74 ndbsetmalloctag(t, getcallerpc(&db));
75 return t;
76 }
77