public FileBasedLock(PhysicalFileSystem fileSystem, ITracer tracer, string lockPath, string signature, ExistingLockCleanup existingLockCleanup)
{
this.fileSystem = fileSystem;
this.tracer = tracer;
this.lockPath = lockPath;
this.Signature = signature;
if (existingLockCleanup != ExistingLockCleanup.LeaveExisting)
{
this.CleanupStaleLock(existingLockCleanup);
}
}
private void CleanupStaleLock(ExistingLockCleanup existingLockCleanup)
{
if (!this.LockFileExists())
{
return;
}
if (existingLockCleanup == ExistingLockCleanup.LeaveExisting)
{
throw new ArgumentException("CleanupStaleLock should not be called with LeaveExisting");
}
EventMetadata metadata = this.CreateLockMetadata();
metadata.Add("existingLockCleanup", existingLockCleanup.ToString());
long length = InvalidFileLength;
try
{
FileProperties existingLockProperties = this.fileSystem.GetFileProperties(this.lockPath);
length = existingLockProperties.Length;
}
catch (Exception e)
{
metadata.Add("Exception", "Exception while getting lock file length: " + e.ToString());
this.tracer.RelatedEvent(EventLevel.Warning, "CleanupEmptyLock", metadata);
}
if (length == 0)
{
metadata.Add("Message", "Deleting empty lock file: " + this.lockPath);
this.tracer.RelatedEvent(EventLevel.Warning, "CleanupEmptyLock", metadata);
}
else
{
metadata.Add("Length", length == InvalidFileLength ? "Invalid" : length.ToString());
switch (existingLockCleanup)
{
case ExistingLockCleanup.DeleteExisting:
metadata.Add("Message", "Deleting stale lock file: " + this.lockPath);
this.tracer.RelatedEvent(EventLevel.Informational, "CleanupExistingLock", metadata);
break;
case ExistingLockCleanup.DeleteExistingAndLogSignature:
string existingSignature;
try
{
string dummyLockerMessage;
this.ReadLockFile(out existingSignature, out dummyLockerMessage);
}
catch (Win32Exception e)
{
if (e.ErrorCode == NativeMethods.ERROR_FILE_NOT_FOUND)
{
// File was deleted before we could read its contents
return;
}
throw;
}
if (existingSignature == this.Signature)
{
metadata.Add("Message", "Deleting stale lock file: " + this.lockPath);
this.tracer.RelatedEvent(EventLevel.Informational, "CleanupExistingLock", metadata);
}
else
{
metadata.Add("ExistingLockSignature", existingSignature);
metadata.Add("Message", "Deleting stale lock file: " + this.lockPath + " with mismatched signature");
this.tracer.RelatedEvent(EventLevel.Warning, "CleanupSignatureMismatchLock", metadata);
}
break;
default:
throw new InvalidOperationException("Invalid ExistingLockCleanup");
}
}
this.fileSystem.DeleteFile(this.lockPath);
}
