Method getMappedRange

fdbclient/ReadYourWrites.actor.cpp:1686–1743

}

Future<MappedRangeResult> ReadYourWritesTransaction::getMappedRange(KeySelector begin,
                                                                    KeySelector end,
                                                                    Key mapper,
                                                                    GetRangeLimits limits,
                                                                    int matchIndex,
                                                                    Snapshot snapshot,
                                                                    Reverse reverse) {
	if (getDatabase()->apiVersionAtLeast(630)) {
		if (specialKeys.contains(begin.getKey()) && specialKeys.begin <= end.getKey() &&
		    end.getKey() <= specialKeys.end) {
			CODE_PROBE(true, "Special key space get range (getMappedRange)");
			throw client_invalid_operation(); // Not support special keys.
		}
	} else {
		if (begin.getKey() == LiteralStringRef("\xff\xff/worker_interfaces")) {
			throw client_invalid_operation(); // Not support special keys.
		}
	}

	if (checkUsedDuringCommit()) {
		return used_during_commit();
	}

	if (resetPromise.isSet())
		return resetPromise.getFuture().getError();

	KeyRef maxKey = getMaxReadKey();
	if (begin.getKey() > maxKey || end.getKey() > maxKey)
		return key_outside_legal_range();

	// This optimization prevents nullptr operations from being added to the conflict range
	if (limits.isReached()) {
		CODE_PROBE(true, "RYW range read limit 0 (getMappedRange)");
		return MappedRangeResult();
	}

	if (!limits.isValid())
		return range_limits_invalid();

	if (begin.orEqual)
		begin.removeOrEqual(begin.arena());

	if (end.orEqual)
		end.removeOrEqual(end.arena());

	if (begin.offset >= end.offset && begin.getKey() >= end.getKey()) {
		CODE_PROBE(true, "RYW range inverted (getMappedRange)");
		return MappedRangeResult();
	}

	Future<MappedRangeResult> result =
	    reverse ? RYWImpl::readWithConflictRangeForGetMappedRange(
	                  this, RYWImpl::GetMappedRangeReq<true>(begin, end, mapper, matchIndex, limits), snapshot)
	            : RYWImpl::readWithConflictRangeForGetMappedRange(
	                  this, RYWImpl::GetMappedRangeReq<false>(begin, end, mapper, matchIndex, limits), snapshot);

	return result;
}