int db_cursor_seekr(DB_cursor *const cursor, DB_range const *const range, DB_val *const key, DB_val *const data, int const dir) {
assert(db_cursor_cmp(cursor, range->min, range->max) < 0);
int rc = db_cursor_seek(cursor, key, data, dir);
if(rc < 0) return rc;
DB_val const *const limit = dir < 0 ? range->min : range->max;
int x = db_cursor_cmp(cursor, key, limit);
if(x * dir < 0) return 0;
db_cursor_clear(cursor);
return DB_NOTFOUND;
}
int SLNSessionGetSubmittedFile(SLNSessionRef const session, DB_txn *const txn, strarg_t const URI) {
uint64_t const sessionID = SLNSessionGetID(session);
DB_cursor *cursor = NULL;
int rc = db_txn_cursor(txn, &cursor);
if(rc < 0) return rc;
DB_range range[1];
DB_val filekey[1];
SLNURIAndFileIDRange1(range, txn, URI);
rc = db_cursor_firstr(cursor, range, filekey, NULL, +1);
if(rc < 0) return rc;
for(; rc >= 0; rc = db_cursor_nextr(cursor, range, filekey, NULL, +1)) {
strarg_t u;
uint64_t fileID;
SLNURIAndFileIDKeyUnpack(filekey, txn, &u, &fileID);
DB_val sessionkey[1];
SLNFileIDAndSessionIDKeyPack(sessionkey, txn, fileID, sessionID);
rc = db_cursor_seek(cursor, sessionkey, NULL, 0);
if(DB_NOTFOUND == rc) continue;
return rc;
}
return SLN_NOSESSION;
}
int db_cursor_firstr(DB_cursor *const cursor, DB_range const *const range, DB_val *const key, DB_val *const data, int const dir) {
assert(db_cursor_cmp(cursor, range->min, range->max) < 0);
if(0 == dir) return DB_EINVAL;
DB_val const *const first = dir > 0 ? range->min : range->max;
DB_val k = *first;
int rc = db_cursor_seek(cursor, &k, data, dir);
if(rc < 0) return rc;
int x = db_cursor_cmp(cursor, &k, first);
assert(x * dir >= 0);
if(0 == x) {
rc = db_cursor_next(cursor, &k, data, dir);
if(rc < 0) return rc;
}
DB_val const *const last = dir < 0 ? range->min : range->max;
x = db_cursor_cmp(cursor, &k, last);
if(x * dir < 0) {
if(key) *key = k;
return 0;
} else {
db_cursor_clear(cursor);
return DB_NOTFOUND;
}
}
int db_get(DB_txn *const txn, DB_val *const key, DB_val *const data) {
DB_cursor *cursor;
int rc = db_txn_cursor(txn, &cursor);
if(rc < 0) return rc;
return db_cursor_seek(cursor, key, data, 0);
}
