Method finishRangeFile

fdbclient/FileBackupAgent.actor.cpp:1081–1129

	//  - save/extend the task with the new params
	// Returns whether or not the caller should continue executing the task.
	ACTOR static Future<bool> finishRangeFile(Reference<IBackupFile> file,
	                                          Database cx,
	                                          Reference<Task> task,
	                                          Reference<TaskBucket> taskBucket,
	                                          KeyRange range,
	                                          Version version) {
		wait(file->finish());

		// Ignore empty ranges.
		if (range.empty())
			return false;

		state Reference<ReadYourWritesTransaction> tr(new ReadYourWritesTransaction(cx));
		state BackupConfig backup(task);
		state bool usedFile = false;

		// Avoid unnecessary conflict by prevent taskbucket's automatic timeout extension
		// because the following transaction loop extends and updates the task.
		wait(task->extendMutex.take());
		state FlowLock::Releaser releaser(task->extendMutex, 1);

		loop {
			try {
				tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
				tr->setOption(FDBTransactionOptions::LOCK_AWARE);

				// Update the start key of the task so if this transaction completes but the task then fails
				// when it is restarted it will continue where this execution left off.
				Params.beginKey().set(task, range.end);

				// Save and extend the task with the new begin parameter
				state Version newTimeout = wait(taskBucket->extendTimeout(tr, task, UpdateParams::True));

				// Update the range bytes written in the backup config
				backup.rangeBytesWritten().atomicOp(tr, file->size(), MutationRef::AddValue);
				backup.snapshotRangeFileCount().atomicOp(tr, 1, MutationRef::AddValue);

				// See if there is already a file for this key which has an earlier begin, update the map if not.
				Optional<BackupConfig::RangeSlice> s = wait(backup.snapshotRangeFileMap().get(tr, range.end));
				if (!s.present() || s.get().begin >= range.begin) {
					backup.snapshotRangeFileMap().set(
					    tr, range.end, { range.begin, version, file->getFileName(), file->size() });
					usedFile = true;
				}

				wait(tr->commit());
				task->timeoutVersion = newTimeout;
				break;
			} catch (Error& e) {
				wait(tr->onError(e));
			}
		}