Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ndb.h>
#include <ndbhf.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*
csgetvalue(char *netroot, char *attr, char *val, char *rattr, Ndbtuple **pp)
{
        Ndbtuple *t, *first, *last;
        int n, linefound;
        char line[1024];
        int fd;
        int oops = 0;
        char *rv;

        if(pp)
                *pp = nil;
        rv = nil;

        if(netroot)
                snprint(line, sizeof(line), "%s/cs", netroot);
        else
                strcpy(line, "/net/cs");
        fd = open(line, ORDWR);
        if(fd < 0)
                return 0;
        seek(fd, 0, 0);
        snprint(line, sizeof(line), "!%s=%s %s=*", attr, val, rattr);
        if(write(fd, line, strlen(line)) < 0){
                close(fd);
                return 0;
        }
        seek(fd, 0, 0);

        first = last = 0;
        linefound = 0;
        for(;;){
                n = read(fd, line, sizeof(line)-2);
                if(n <= 0)
                        break;
                line[n] = '\n';
                line[n+1] = 0;

                t = _ndbparseline(line);
                if(t == 0)
                        continue;
                if(first)
                        last->entry = t;
                else
                        first = t;
                last = t;

                while(last->entry)
                        last = last->entry;

                for(; t; t = t->entry){
                        if(linefound == 0){
                                if(strcmp(rattr, t->attr) == 0){
                                        linefound = 1;
                                        rv = strdup(t->val);
                                }
                        }
                }
        }
        close(fd);

        if(oops){
                werrstr("buffer too short");
                ndbfree(first);
                return nil;
        }

        if(pp){
                setmalloctag(first, getcallerpc(&netroot));
                *pp = first;
        } else
                ndbfree(first);

        return rv;
}

Ndbtuple*
csgetval(char *netroot, char *attr, char *val, char *rattr, char *buf)
{
        Ndbtuple *t;
        char *p;

        p = csgetvalue(netroot, 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(&netroot));
        return t;
}