internal void Initialize()
{
this.tempFileName = Utility.GetTempFileName();
FileStream tmpFileStream = FabricFile.Open(this.tempFileName, FileMode.Create, FileAccess.Write);
#if !DotNetCoreClrLinux
Helpers.SetIoPriorityHint(tmpFileStream.SafeFileHandle, Kernel32Types.PRIORITY_HINT.IoPriorityHintVeryLow);
#endif
this.fileStream = new StreamWriter(tmpFileStream);
this.writeStatistics = new Statistics();
}
internal bool Update(Dictionary <string, ServicePackageTableRecord> servicePackageTable, EtwEventTimestamp latestDataTimestamp)
{
// Create a new temp file
string tempFilePath = Utility.GetTempFileName();
string backupFilePath = string.Empty;
try
{
// Open the temp file
StreamWriter writer = null;
try
{
Utility.PerformIOWithRetries(
() =>
{
FileStream file = FabricFile.Open(tempFilePath, FileMode.Create, FileAccess.Write);
#if !DotNetCoreClrLinux
Helpers.SetIoPriorityHint(file.SafeFileHandle, Kernel32Types.PRIORITY_HINT.IoPriorityHintVeryLow);
#endif
writer = new StreamWriter(file);
});
}
catch (Exception e)
{
Utility.TraceSource.WriteExceptionAsError(
TraceType,
e,
"Failed to open temp file {0}.",
tempFilePath);
return(false);
}
try
{
// Write the version information to the backup file
try
{
Utility.PerformIOWithRetries(
() =>
{
writer.WriteLine(BackupFileVersionString);
});
}
catch (Exception e)
{
Utility.TraceSource.WriteExceptionAsError(
TraceType,
e,
"Failed to write version information to temp file {0}.",
tempFilePath);
return(false);
}
// Write the table records to the backup file
foreach (string tableKey in servicePackageTable.Keys)
{
string tableRecord = string.Concat(
servicePackageTable[tableKey].NodeName,
", ",
servicePackageTable[tableKey].ApplicationInstanceId,
", ",
servicePackageTable[tableKey].ApplicationRolloutVersion,
", ",
servicePackageTable[tableKey].ServicePackageName,
", ",
servicePackageTable[tableKey].ServiceRolloutVersion,
", ",
servicePackageTable[tableKey].RunLayoutRoot);
try
{
Utility.PerformIOWithRetries(
() =>
{
writer.WriteLine(tableRecord);
});
}
catch (Exception e)
{
Utility.TraceSource.WriteExceptionAsError(
TraceType,
e,
"Failed to write record {0} to temp file {1}",
tableRecord,
tempFilePath);
return(false);
}
}
}
finally
{
writer.Dispose();
}
// Compute the name of the backup file
long timstampBinary = latestDataTimestamp.Timestamp.ToBinary();
string fileName = string.Concat(
BackupFilePrefix,
timstampBinary.ToString("D20", CultureInfo.InvariantCulture),
"_",
latestDataTimestamp.Differentiator.ToString("D10", CultureInfo.InvariantCulture),
".",
BackupFileExt);
backupFilePath = Path.Combine(this.backupDirectory, fileName);
// Copy the temp file as the new backup file
try
{
Utility.PerformIOWithRetries(
() =>
{
FabricFile.Copy(tempFilePath, backupFilePath, true);
});
}
catch (Exception e)
{
Utility.TraceSource.WriteExceptionAsError(
TraceType,
e,
"Failed to copy file {0} to {1}",
tempFilePath,
backupFilePath);
return(false);
}
Utility.TraceSource.WriteInfo(
TraceType,
"Backup file {0} created. The backup file is valid up to timestamp {1} ({2}, {3}).",
backupFilePath,
latestDataTimestamp.Timestamp,
latestDataTimestamp.Timestamp.Ticks,
latestDataTimestamp.Differentiator);
}
finally
{
try
{
Utility.PerformIOWithRetries(
() =>
{
FabricFile.Delete(tempFilePath);
});
}
catch (Exception e)
{
Utility.TraceSource.WriteExceptionAsError(
TraceType,
e,
"Failed to delete temp file {0}",
tempFilePath);
}
}
// Update the latest backup time
this.LatestBackupTime = latestDataTimestamp;
// Delete older backup files
string backupFilePattern = string.Concat(
BackupFilePrefix,
"*.",
BackupFileExt);
string[] backupFiles = FabricDirectory.GetFiles(
this.backupDirectory,
backupFilePattern);
foreach (string fileToDelete in backupFiles)
{
if (fileToDelete.Equals(
backupFilePath,
StringComparison.OrdinalIgnoreCase))
{
// Don't delete the current backup file
continue;
}
try
{
Utility.PerformIOWithRetries(
() =>
{
FabricFile.Delete(fileToDelete);
});
}
catch (Exception e)
{
// Deletion is on a best-effort basis. Log an error and
// continue.
Utility.TraceSource.WriteExceptionAsError(
TraceType,
e,
"Failed to delete old backup file {0}",
fileToDelete);
}
}
return(true);
}
