void scanDescending(RecordListResponse& _return, TreeDB* db,
const std::string& startKey, const bool startKeyIncluded,
const std::string& endKey, const bool endKeyIncluded,
const int32_t maxRecords, const int32_t maxBytes) {
int numBytes = 0;
DB::Cursor* cursor = db->cursor();
_return.responseCode = ResponseCode::ScanEnded;
if (endKey.empty()) {
if (!cursor->jump_back()) {
delete cursor;
return;
}
} else {
if (!cursor->jump_back(endKey)) {
delete cursor;
return;
}
}
string key, value;
while (cursor->get(&key, &value, false /* step */)) {
if (!endKeyIncluded && key == endKey) {
cursor->step_back();
continue;
}
if (startKeyIncluded && startKey > key) {
break;
}
if (!startKeyIncluded && startKey >= key) {
break;
}
Record record;
record.key = key;
record.value = value;
numBytes += record.key.size() + record.value.size();
_return.records.push_back(record);
if (_return.records.size() >= (uint32_t)maxRecords || numBytes >= maxBytes) {
_return.responseCode = ResponseCode::Success;
break;
}
cursor->step_back();
}
delete cursor;
}
