Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <bio.h>
#include "ndb.h"

/*
 *  search for a tuple that has the given 'attr=val' and also 'rattr=x'.
 *  copy 'x' into 'buf' and return the whole tuple.
 *
 *  return 0 if not found.
 */
char*
ndbgetvalue(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, Ndbtuple **pp)
{
        Ndbtuple *t, *nt;
        char *rv;
        Ndbs temps;

        if(s == nil)
                s = &temps;
        if(pp)
                *pp = nil;
        t = ndbsearch(db, s, attr, val);
        while(t){
                /* first look on same line (closer binding) */
                nt = s->t;
                for(;;){
                        if(strcmp(rattr, nt->attr) == 0){
                                rv = strdup(nt->val);
                                if(pp != nil)
                                        *pp = t;
                                else
                                        ndbfree(t);
                                return rv;
                        }
                        nt = nt->line;
                        if(nt == s->t)
                                break;
                }
                /* search whole tuple */
                for(nt = t; nt; nt = nt->entry){
                        if(strcmp(rattr, nt->attr) == 0){
                                rv = strdup(nt->val);
                                if(pp != nil)
                                        *pp = t;
                                else
                                        ndbfree(t);
                                return rv;
                        }
                }
                ndbfree(t);
                t = ndbsnext(s, attr, val);
        }
        return nil;
}

Ndbtuple*
ndbgetval(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, char *buf)
{
        Ndbtuple *t;
        char *p;

        p = ndbgetvalue(db, s, attr, val, rattr, &t);
        if(p == nil){
                if(buf != nil)
                        *buf = 0;
        } else {
                if(buf != nil){
                        strncpy(buf, p, Ndbvlen-1);
                        buf[Ndbvlen-1] = 0;
                }
                free(p);
        }
        ndbsetmalloctag(t, getcallerpc(&db));
        return t;
}