Job failure in cleanDeletedFiles()

[lberrymage]

Server logs indicate a bug in the implementation of cleanDeletedFiles():

ERROR o.j.server.BackgroundJobPerformer - Job(id=2e94613b-a8cd-4196-8dc2-a504f1086b58, jobName='app.accrescent.parcelo.console.jobs.CleanDeletedFilesKt.cleanDeletedFiles()') processing failed: An exception occurred during the performance of the job
java.lang.IllegalStateException: Batch is empty

This appears to be the result of unconditionally sending object storage deletion requests even when there are no objects staged for deletion. This behavior is exhibited in both the S3 and GCS object storage providers:

parcelo/console/src/main/kotlin/app/accrescent/parcelo/console/storage/S3ObjectStorageService.kt

Lines 121 to 141 in 0a517ad

	val deleteObjectsRequest = transaction {
	files
	.map { ObjectIdentifier { key = it.s3ObjectKey } }
	.let { Delete { objects = it } }
	.let {
	DeleteObjectsRequest {
	bucket = s3Bucket
	delete = it
	}
	}
	}
	S3Client {
	endpointUrl = s3EndpointUrl
	region = s3Region
	credentialsProvider = StaticCredentialsProvider {
	accessKeyId = s3AccessKeyId
	secretAccessKey = s3SecretAccessKey
	}
	}.use { s3Client ->
	s3Client.deleteObjects(deleteObjectsRequest)

parcelo/console/src/main/kotlin/app/accrescent/parcelo/console/storage/GCSObjectStorageService.kt

Lines 73 to 75 in 0a517ad

	val blobsToDelete = transaction { files.map { BlobId.of(bucket, it.s3ObjectKey) } }
	storage.delete(blobsToDelete)

This can most likely be fixed by only sending the constructed deletion request if there is at least one object to delete.