protected override async Task <Tuple <bool, JObject> > TryObtainLockAsync(string lockMessage, CancellationToken token)
{
var result = false;
var json = new JObject();
try
{
if (await FileExistsAsync(client, bucketName, LockFile, token).ConfigureAwait(false))
{
// Read the existing message
json = await GetExistingMessage(json, token);
}
else
{
// Create a new lock
json = GetMessageJson(lockMessage);
await CreateFileAsync(client, bucketName, LockFile, json.ToString(), serverSideEncryptionMethod, token).ConfigureAwait(false);
result = true;
}
}
catch (AmazonS3Exception ex) when
(ex.StatusCode != HttpStatusCode.Forbidden &&
ex.StatusCode != HttpStatusCode.Unauthorized &&
ex.StatusCode != HttpStatusCode.BadRequest)
{
// Ignore and retry, there may be a race case writing the lock file.
ExceptionUtilsSleetLib.LogException(ex, Log, LogLevel.Verbose);
}
return(Tuple.Create(result, json));
}
private async Task <JObject> GetMessageJson()
{
try
{
var text = await _messageBlob.DownloadTextAsync();
return(JObject.Parse(text));
}
catch (Exception ex)
{
// ignore
ExceptionUtilsSleetLib.LogException(ex, Log, LogLevel.Debug);
}
return(new JObject());
}
private async Task KeepLock()
{
var renewTime = TimeSpan.FromSeconds(15);
try
{
while (!_cts.IsCancellationRequested)
{
try
{
await _lease.Renew();
await Task.Delay(renewTime, _cts.Token);
}
catch (TaskCanceledException)
{
// Ignore
}
catch (Exception ex)
{
// Ignore
Log.LogWarning("Failed to renew lock on feed. If another client takes the lock conflicts could occur.");
ExceptionUtilsSleetLib.LogException(ex, Log, LogLevel.Warning);
}
}
// Exit lock
// Make sure writing to the lock finished
await _updateLockMessage;
// Delete the message file
await _messageBlob.DeleteIfExistsAsync();
}
catch (Exception ex)
{
// Ignore
Log.LogWarning("Unable to clear lock messsage");
ExceptionUtilsSleetLib.LogException(ex, Log, LogLevel.Warning);
}
}
protected override async Task <Tuple <bool, JObject> > TryObtainLockAsync(string lockMessage, CancellationToken token)
{
var result = false;
var json = new JObject();
try
{
if (File.Exists(LockFile))
{
// Read message from existing lock file
json = await JsonUtility.LoadJsonAsync(LockPath);
}
else
{
// Obtain the lock
Directory.CreateDirectory(Path.GetDirectoryName(LockPath));
json = GetMessageJson(lockMessage);
json.Add(new JProperty("pid", Process.GetCurrentProcess().Id));
using (var stream = new FileStream(LockPath, FileMode.CreateNew))
{
await JsonUtility.WriteJsonAsync(json, stream);
}
result = true;
}
}
catch (Exception ex)
{
// Ignore and retry
ExceptionUtilsSleetLib.LogException(ex, Log, LogLevel.Debug);
}
return(Tuple.Create(result, json));
}