Method clearDescendants

src/QLContext.actor.cpp:229–235

	}

	void clearDescendants(Reference<DocTransaction> tr, DataKey key) override {
		std::string _key = getFDBKey(key);

		KeyRange kr = KeyRangeRef(_key + '\x00', _key + '\xFF');
		auto docDeferred = findOrCreate(tr, key);
		docDeferred->deferred.emplace_back([kr](Reference<DocTransaction> tr) { tr->tr->clear(kr); });
	}

	void clear(Reference<DocTransaction> tr, DataKey key) override {
		std::string k = getFDBKey(key);