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- #include <u.h>
- #include <libc.h>
- #include <bio.h>
- #include <ndb.h>
- /*
- * reorder the tuple to put x's line first in the entry and x fitst in its line
- */
- Ndbtuple*
- ndbreorder(Ndbtuple *t, Ndbtuple *x)
- {
- Ndbtuple *nt;
- Ndbtuple *last, *prev;
- /* if x is first, we're done */
- if(x == t)
- return t;
- /* find end of x's line */
- for(last = x; last->line == last->entry; last = last->line)
- ;
- /* rotate to make this line first */
- if(last->line != t){
- /* detach this line and everything after it from the entry */
- for(nt = t; nt->entry != last->line; nt = nt->entry)
- ;
- nt->entry = nil;
-
- /* switch */
- for(nt = last; nt->entry != nil; nt = nt->entry)
- ;
- nt->entry = t;
- }
- /* rotate line to make x first */
- if(x != last->line){
- /* find entry before x */
- for(prev = last; prev->line != x; prev = prev->line);
- ;
- /* detach line */
- nt = last->entry;
- last->entry = last->line;
- /* reattach */
- prev->entry = nt;
- }
- return x;
- }
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