/// <summary>
/// Create a new <see cref="RecoveryPointMetadataFile"/> and write it to the given file.
/// </summary>
/// <returns>Task that represents the asynchronous operation.</returns>
public static async Task <RecoveryPointMetadataFile> CreateAsync(
string fileName,
DateTime backupTime,
Guid backupId,
Guid parentBackupId,
Guid backupChainId,
Epoch epochOfLastBackupRecord,
long lsnOfLastBackupRecord,
string backupLocation,
string parentBackupLocation,
ServicePartitionInformation partitionInformation,
string serviceManifestVersion,
CancellationToken cancellationToken)
{
// Create the file with asynchronous flag and 4096 cache size (C# default).
using (var filestream = FabricFile.Open(
fileName,
FileMode.CreateNew,
FileAccess.Write,
FileShare.Read,
4096,
FileOptions.Asynchronous))
{
BackupRestoreUtility.SetIoPriorityHint(filestream.SafeFileHandle, Kernel32Types.PRIORITY_HINT.IoPriorityHintLow);
var recoveryPointMetadataFile = new RecoveryPointMetadataFile(fileName);
recoveryPointMetadataFile.properties = new RecoveryPointMetadataFileProperties
{
BackupTime = backupTime,
BackupLocation = backupLocation,
ParentBackupLocation = parentBackupLocation,
BackupId = backupId,
ParentBackupId = parentBackupId,
BackupChainId = backupChainId,
EpochOfLastBackupRecord = epochOfLastBackupRecord,
LsnOfLastBackupRecord = lsnOfLastBackupRecord,
PartitionInformation = partitionInformation,
ServiceManifestVersion = serviceManifestVersion,
};
// Write the properties.
var propertiesHandle =
await FileBlock.WriteBlockAsync(filestream, writer => recoveryPointMetadataFile.properties.Write(writer)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
// Write the footer.
recoveryPointMetadataFile.footer = new FileFooter(propertiesHandle, Version);
await FileBlock.WriteBlockAsync(filestream, writer => recoveryPointMetadataFile.footer.Write(writer)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
// Flush to underlying stream.
await filestream.FlushAsync(cancellationToken).ConfigureAwait(false);
return(recoveryPointMetadataFile);
}
}
public static async Task <RecoveryPointMetadataFile> OpenAsync(
Stream filestream,
string recoveryPointMetadataFilePath,
CancellationToken cancellationToken)
{
var recoveryPointMetadataFile = new RecoveryPointMetadataFile(recoveryPointMetadataFilePath);
// Read and validate the Footer section. The footer is always at the end of the stream, minus space for the checksum.
var footerHandle = new BlockHandle(
filestream.Length - FileFooter.SerializedSize - sizeof(ulong),
FileFooter.SerializedSize);
recoveryPointMetadataFile.footer =
await
FileBlock.ReadBlockAsync(
filestream,
footerHandle,
(reader, handle) => FileFooter.Read(reader, handle)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
// Verify we know how to deserialize this version of the backup log file.
if (recoveryPointMetadataFile.footer.Version != Version)
{
throw new InvalidDataException(
string.Format(
CultureInfo.CurrentCulture,
SR.Error_BackupMetadata_Deserialized,
recoveryPointMetadataFile.footer.Version,
Version));
}
// Read and validate the properties section.
var propertiesHandle = recoveryPointMetadataFile.footer.PropertiesHandle;
recoveryPointMetadataFile.properties =
await
FileBlock.ReadBlockAsync(
filestream,
propertiesHandle,
(reader, handle) => FileProperties.Read <RecoveryPointMetadataFileProperties>(reader, handle)).ConfigureAwait(false);
cancellationToken.ThrowIfCancellationRequested();
return(recoveryPointMetadataFile);
}
