int hammy_del(ErlNifEnv *env, hammy_db *db, unsigned char *key, int key_size) {
ham_key_t k;
ham_txn_t *txn;
int retval = HAMMY_FALSE;
setup_key(&k, key, key_size);
ham_txn_begin(&txn, db->databases[0], HAM_TXN_READ_ONLY);
if (ham_erase(db->databases[0], txn, &k, 0) == HAM_SUCCESS) {
ham_txn_commit(txn, 0);
retval = HAMMY_TRUE;
}
else {
ham_txn_abort(txn, 0);
}
return retval;
}
int
main(int argc, char **argv)
{
int i;
ham_status_t st; /* status variable */
ham_db_t *db; /* hamsterdb database object */
ham_key_t key; /* the structure for a key */
ham_record_t record; /* the structure for a record */
memset(&key, 0, sizeof(key));
memset(&record, 0, sizeof(record));
/*
* first step: create a new hamsterdb object
*/
st=ham_new(&db);
if (st!=HAM_SUCCESS)
error("ham_new", st);
/*
* second step: create a new hamsterdb database
*
* we could also use ham_create_ex() if we wanted to specify the
* page size, key size or cache size limits
*/
st=ham_create_ex(db, "test.db", 0, 0664, 0);
if (st!=HAM_SUCCESS)
error("ham_create", st);
/*
* now we can insert, delete or lookup values in the database
*
* for our test program, we just insert a few values, then look them
* up, then delete them and try to look them up again (which will fail).
*/
for (i=0; i<LOOP; i++) {
key.data=&i;
key.size=sizeof(i);
record.data=&i;
record.size=sizeof(i);
st=ham_insert(db, 0, &key, &record, 0);
if (st!=HAM_SUCCESS)
error("ham_insert", st);
}
/*
* now lookup all values
*
* for ham_find(), we could use the flag HAM_RECORD_USER_ALLOC, if WE
* allocate record.data (otherwise the memory is automatically allocated
* by hamsterdb)
*/
for (i=0; i<LOOP; i++) {
key.data=&i;
key.size=sizeof(i);
st=ham_find(db, 0, &key, &record, 0);
if (st!=HAM_SUCCESS)
error("ham_find", st);
/*
* check if the value is ok
*/
if (*(int *)record.data!=i) {
printf("ham_find() ok, but returned bad value\n");
return (-1);
}
}
/*
* close the database handle, then re-open it (to demonstrate the
* call ham_open)
*/
st=ham_close(db, 0);
if (st!=HAM_SUCCESS)
error("ham_close", st);
st=ham_open_ex(db, "test.db", 0, 0);
if (st!=HAM_SUCCESS)
error("ham_open", st);
/*
* now erase all values
*/
for (i=0; i<LOOP; i++) {
key.size=sizeof(i);
key.data=&i;
st=ham_erase(db, 0, &key, 0);
if (st!=HAM_SUCCESS)
error("ham_erase", st);
}
/*
* once more we try to find all values... every ham_find() call must
* now fail with HAM_KEY_NOT_FOUND
*/
for (i=0; i<LOOP; i++) {
key.size=sizeof(i);
key.data=&i;
st=ham_find(db, 0, &key, &record, 0);
if (st!=HAM_KEY_NOT_FOUND)
error("ham_find", st);
}
/*
* we're done! close the database handle
*/
st=ham_close(db, 0);
if (st!=HAM_SUCCESS)
error("ham_close", st);
/*
* delete the database object to avoid memory leaks
*/
ham_delete(db);
#if UNDER_CE
error("success", 0);
#endif
printf("success!\n");
return (0);
}
