Function constructMappedKey

fdbserver/storageserver.actor.cpp:4106–4150

}

Key constructMappedKey(KeyValueRef* keyValue,
                       std::vector<Optional<Tuple>>& vec,
                       Tuple& mappedKeyTuple,
                       Tuple& mappedKeyFormatTuple) {
	// Lazily parse key and/or value to tuple because they may not need to be a tuple if not used.
	Optional<Tuple> keyTuple;
	Optional<Tuple> valueTuple;
	mappedKeyTuple.clear();
	mappedKeyTuple.reserve(vec.size());

	for (int i = 0; i < vec.size(); i++) {
		if (!vec[i].present()) {
			// rangeQuery
			continue;
		}
		if (vec[i].get().size()) {
			mappedKeyTuple.append(vec[i].get());
		} else {
			// singleKeyOrValue is true
			std::string s = mappedKeyFormatTuple.getString(i).toString();
			auto sz = s.size();
			int idx;
			Tuple* referenceTuple;
			try {
				idx = std::stoi(s.substr(3, sz - 5));
			} catch (std::exception& e) {
				throw mapper_bad_index();
			}
			if (s[1] == 'K') {
				unpackKeyTuple(&referenceTuple, keyTuple, keyValue);
			} else if (s[1] == 'V') {
				unpackValueTuple(&referenceTuple, valueTuple, keyValue);
			} else {
				ASSERT(false);
				throw internal_error();
			}
			if (idx < 0 || idx >= referenceTuple->size()) {
				throw mapper_bad_index();
			}
			mappedKeyTuple.appendRaw(referenceTuple->subTupleRawString(idx));
		}
	}

	return mappedKeyTuple.pack();
}

TEST_CASE("/fdbserver/storageserver/constructMappedKey") {
	Key key = Tuple::makeTuple("key-0"_sr, "key-1"_sr, "key-2"_sr).getDataAsStandalone();