Method getCachedLocations

fdbclient/NativeAPI.actor.cpp:1855–1895

}

bool DatabaseContext::getCachedLocations(const Optional<TenantNameRef>& tenantName,
                                         const KeyRangeRef& range,
                                         std::vector<KeyRangeLocationInfo>& result,
                                         int limit,
                                         Reverse reverse) {
	result.clear();

	TenantMapEntry tenantEntry;
	Arena arena;
	KeyRangeRef resolvedRange = range;

	if (tenantName.present()) {
		auto itr = tenantCache.find(tenantName.get());
		if (itr != tenantCache.end()) {
			tenantEntry = itr->second;
			resolvedRange = resolvedRange.withPrefix(tenantEntry.prefix, arena);
		} else {
			return false;
		}
	}

	auto begin = locationCache.rangeContaining(resolvedRange.begin);
	auto end = locationCache.rangeContainingKeyBefore(resolvedRange.end);

	loop {
		auto r = reverse ? end : begin;
		if (!r->value()) {
			CODE_PROBE(result.size(), "had some but not all cached locations");
			result.clear();
			return false;
		}
		result.emplace_back(tenantEntry, toRelativeRange(r->range() & resolvedRange, tenantEntry.prefix), r->value());
		if (result.size() == limit || begin == end) {
			break;
		}

		if (reverse)
			--end;
		else
			++begin;
	}

	return true;
}