Method setFile

fdbserver/DiskQueue.actor.cpp:262–265

		File() : size(-1), popped(-1) {}

		void setFile(Reference<IAsyncFile> f) {
			this->f = f;
			this->syncQueue = makeReference<SyncQueue>(1, f);
		}
	};
	File files[2]; // After readFirstAndLastPages(), files[0] is logically before files[1] (pushes are always into
	               // files[1])