Method _execute

fdbclient/DatabaseBackupAgent.actor.cpp:209–256

	}

	ACTOR static Future<Void> _execute(Database cx,
	                                   Reference<TaskBucket> taskBucket,
	                                   Reference<FutureBucket> futureBucket,
	                                   Reference<Task> task) {
		state Reference<FlowLock> lock(new FlowLock(CLIENT_KNOBS->BACKUP_LOCK_BYTES));
		state Subspace conf = Subspace(databaseBackupPrefixRange.begin)
		                          .get(BackupAgentBase::keyConfig)
		                          .get(task->params[BackupAgentBase::keyConfigLogUid]);

		wait(checkTaskVersion(cx, task, BackupRangeTaskFunc::name, BackupRangeTaskFunc::version));
		// Find out if there is a shard boundary in(beginKey, endKey)
		Standalone<VectorRef<KeyRef>> keys =
		    wait(runRYWTransaction(taskBucket->src, [=](Reference<ReadYourWritesTransaction> tr) {
			    return getBlockOfShards(tr,
			                            task->params[DatabaseBackupAgent::keyBeginKey],
			                            task->params[DatabaseBackupAgent::keyEndKey],
			                            CLIENT_KNOBS->BACKUP_SHARD_TASK_LIMIT);
		    }));
		if (keys.size() > 0) {
			task->params[BackupRangeTaskFunc::keyAddBackupRangeTasks] = BinaryWriter::toValue(keys, IncludeVersion());
			return Void();
		}

		// Read everything from beginKey to endKey, write it to an output file, run the output file processor, and
		// then set on_done.If we are still writing after X seconds, end the output file and insert a new backup_range
		// task for the remainder.
		state double timeout = now() + CLIENT_KNOBS->BACKUP_RANGE_TIMEOUT;
		state Key addPrefix = task->params[DatabaseBackupAgent::keyAddPrefix];
		state Key removePrefix = task->params[DatabaseBackupAgent::keyRemovePrefix];

		state KeyRange range(
		    KeyRangeRef(task->params[BackupAgentBase::keyBeginKey], task->params[BackupAgentBase::keyEndKey]));

		// retrieve kvData
		state PromiseStream<RangeResultWithVersion> results;

		state Future<Void> rc = readCommitted(
		    taskBucket->src, results, lock, range, Terminator::True, AccessSystemKeys::True, LockAware::True);
		state Key rangeBegin = range.begin;
		state Key rangeEnd;
		state bool endOfStream = false;
		state RangeResultWithVersion nextValues;
		state int64_t nextValuesSize = 0;
		nextValues.second = invalidVersion;
		loop {
			if (endOfStream && nextValues.second == invalidVersion) {
				return Void();
			}
			state RangeResultWithVersion values = std::move(nextValues);
			state int64_t valuesSize = nextValuesSize;
			nextValues = RangeResultWithVersion();