76 lines
1.3 KiB
C
76 lines
1.3 KiB
C
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#include <u.h>
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#include <libc.h>
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#include <bio.h>
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#include "ndb.h"
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/*
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* search for a tuple that has the given 'attr=val' and also 'rattr=x'.
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* copy 'x' into 'buf' and return the whole tuple.
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*
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* return 0 if not found.
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*/
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char*
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ndbgetvalue(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, Ndbtuple **pp)
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{
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Ndbtuple *t, *nt;
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char *rv;
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Ndbs temps;
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if(s == nil)
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s = &temps;
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if(pp)
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*pp = nil;
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t = ndbsearch(db, s, attr, val);
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while(t){
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/* first look on same line (closer binding) */
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nt = s->t;
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for(;;){
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if(strcmp(rattr, nt->attr) == 0){
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rv = strdup(nt->val);
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if(pp != nil)
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*pp = t;
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else
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ndbfree(t);
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return rv;
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}
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nt = nt->line;
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if(nt == s->t)
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break;
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}
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/* search whole tuple */
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for(nt = t; nt; nt = nt->entry){
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if(strcmp(rattr, nt->attr) == 0){
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rv = strdup(nt->val);
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if(pp != nil)
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*pp = t;
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else
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ndbfree(t);
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return rv;
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}
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}
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ndbfree(t);
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t = ndbsnext(s, attr, val);
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}
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return nil;
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}
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Ndbtuple*
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ndbgetval(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, char *buf)
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{
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Ndbtuple *t;
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char *p;
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p = ndbgetvalue(db, s, attr, val, rattr, &t);
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if(p == nil){
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if(buf != nil)
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*buf = 0;
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} else {
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if(buf != nil){
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strncpy(buf, p, Ndbvlen-1);
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buf[Ndbvlen-1] = 0;
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}
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free(p);
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}
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return t;
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}
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