hi all,

i can't seem to make stat work for me. i can use stat_print and it
gives me the correct number of records in the db, and after inspecting
the source for stat_print i can't work out what's going wrong.

the following code creates a db, adds records and then stat_print's the
db, and finally, stat's the db and the result is different to
stat_print.

help much appreciated,


jack


#include <db.h>
#include <assert.h>
typedef int I;
typedef void*P;
#define DC(ex) do{I RV=(ex);if((RV))printf("DC:%d,
%s\n",RV,db_strerror(RV));\ assert(!(RV));}while(0)
#define DCL(fn,args...) DC(db->fn(db,##args))
DB *db;
create()
{DC(db_create(&db,0,0));db->set_errfile(db,stdout);
DCL(open,0,"rn.db",0,DB_RECNO,DB_TRUNCATE|DB_CREAT E,0);
}
db_recno_t add(void *p,size_t z)
{DBT ts[2],*k=&ts[0],*v=&ts[1];
I i;for(i=0;i<2;i++)memset(&ts[i],0,sizeof(DBT));
v->data=p;v->size=v->ulen=z;v->flags=DB_DBT_USERMEM;
k->flags=DB_DBT_MALLOC;
DCL(put,0,k,v,DB_APPEND);
return *(I*)k->data;
}
stat()
{DCL(sync,0);
DCL(stat_print,0);
DB_BTREE_STAT sp; DCL(stat,0,&sp,0);
printf("\nnkeys: %lu\n\n",(u_long)sp.bt_nkeys);
}
main() {create(); I i;for(i=0;i<4;i++)add(&i,sizeof(I)); stat(); }

effbiae <effbiae (AT) ivorykite (DOT) com> writes:
The second argument to DB->stat() should be the address of a _pointer_
to a DB_whatever_STAT structure, not the address of such a structure.
Ergo, your stat() routine should read:

void
stat(void)
{
DCL(sync,0);
DCL(stat_print,0);

DB_BTREE_STAT *sp;
DCL(stat, 0, &sp, 0);
printf("\nnkeys: %lu\n\n", (unsigned long)sp->bt_nkeys);
free(sp);
}


Philip Guenther

(I'll note that your code has undefined behavior because it falls off
the end of functions with 'int' return type. Yep, leaving off the
return type from a function means that it returns 'int'. Or at least it
_did_, as that was deprecated in the C89 standard and made a constraint
violation in the C99 standard. Not even gcc defines the results, so
your program may continue to behave weirdly until you fix that...)