/// <summary>
/// Loads a clean copy of the model and passes it to the given
/// block, which should apply changes to that model that can
/// be retried from scratch multiple times until successful.
///
/// This method will return the final state of the saved model.
/// The caller should use this afterward, instead of the instance
/// it had passed in to the call.
/// </summary>
/// <param name="model">The model.</param>
/// <param name="block">The block.</param>
/// <returns>the latest version of the model provided to the method</returns>
public virtual T UpdateDocumentWithRetry(T model, Action <T> block)
{
var documentKey = model.Key;
var success = false;
T documentToReturn = null;
while (!success)
{
// load a clean copy of the document
var latestDocument = GetDocument(documentKey);
// if we were unable to find a document then create the document and
// return the latest version of the document to the caller
if (latestDocument == null)
{
return(CreateDocument(model));
}
// pass the latest document to the given block so the latest changes can be applied
if (block != null)
{
block(latestDocument);
}
latestDocument.Version += 1;
latestDocument.UpdatedAt = SetUpdatedAtWithNoTimeTravel(model.UpdatedAt);
var latestDocumentJson = latestDocument.ToJson();
var storeResult = Client.ExecuteCas(StoreMode.Replace, latestDocument.Key, latestDocumentJson,
latestDocument.CasValue);
if (!storeResult.Success)
{
continue;
}
documentToReturn = latestDocument;
success = true;
}
return(documentToReturn);
}