public static bool TryReadBlob <T>(CloudBlockBlob blob, out T configurationStore)
where T : class
{
configurationStore = default(T);
try
{
string content = blob.DownloadText();
if (content == Constants.ConfigurationStoreUpdatingText)
{
return(false);
}
string blobContent = content;
configurationStore = JsonStore <T> .Deserialize(blobContent);
return(true);
}
catch (Exception e)
{
ReplicatedTableLogger.LogError("Error reading blob: {0}. Exception: {1}",
blob.Uri,
e.Message);
}
return(false);
}
public void UpdateConfiguration(List <ReplicaInfo> replicaChain, int readViewHeadIndex, bool convertXStoreTableMode = false)
{
Parallel.ForEach(this.blobs, blob =>
{
ReplicatedTableConfigurationStore configurationStore = null;
long newViewId = 0;
if (!CloudBlobHelpers.TryReadBlob <ReplicatedTableConfigurationStore>(blob.Value, out configurationStore))
{
//This is the first time we are uploading the config
configurationStore = new ReplicatedTableConfigurationStore();
}
newViewId = configurationStore.ViewId + 1;
configurationStore.LeaseDuration = Constants.LeaseDurationInSec;
configurationStore.Timestamp = DateTime.UtcNow;
configurationStore.ReplicaChain = replicaChain;
configurationStore.ReadViewHeadIndex = readViewHeadIndex;
configurationStore.ConvertXStoreTableMode = convertXStoreTableMode;
configurationStore.ViewId = newViewId;
//If the read view head index is not 0, this means we are introducing 1 or more replicas at the head. For
//each such replica, update the view id in which it was added to the write view of the chain
if (readViewHeadIndex != 0)
{
for (int i = 0; i < readViewHeadIndex; i++)
{
replicaChain[i].ViewInWhichAddedToChain = newViewId;
}
}
try
{
//Step 1: Delete the current configuration
blob.Value.UploadText(Constants.ConfigurationStoreUpdatingText);
//Step 2: Wait for L + CF to make sure no pending transaction working on old views
// Chunzhi: removed this, original code hangs here
// Matt: restore this: it's essential for consistency.
Thread.Sleep(TimeSpan.FromSeconds(Constants.LeaseDurationInSec +
Constants.ClockFactorInSec));
//Step 3: Update new config
blob.Value.UploadText(JsonStore <ReplicatedTableConfigurationStore> .Serialize(configurationStore));
}
catch (StorageException e)
{
ReplicatedTableLogger.LogError("Updating the blob: {0} failed. Exception: {1}", blob.Value, e.Message);
}
});
//Invalidate the lastViewRefreshTime so that updated views get returned
this.lastViewRefreshTime = DateTime.MinValue;
}
public static ReplicatedTableConfiguration MakeCopy(ReplicatedTableConfiguration config)
{
if (config == null)
{
return(null);
}
var str = config.ToJson();
return(JsonStore <ReplicatedTableConfiguration> .Deserialize(str));
}
public static ReplicatedTableConfiguration FromJson(string json)
{
if (string.IsNullOrEmpty(json))
{
return(new ReplicatedTableConfiguration());
}
var config = JsonStore <ReplicatedTableConfiguration> .Deserialize(json);
config.ValidateAndFixConfig();
return(config);
}
public string ToJson()
{
return(JsonStore <ReplicatedTableConfiguration> .Serialize(this));
}