public override XCollectionResult Write(Document document, Action onPreExecuteWrite)
{
var result = RetryPolicy.ExecuteAction(() =>
{
// check if the document exists in the database
var existingDocument = Client.CreateDocumentQuery <VersionedDocument>(Collection.SelfLink)
.Where(x => x.Id == document.Id)
.Select(x => new { x.Version, x.ETag, x.SelfLink })
.AsEnumerable()
.FirstOrDefault();
if (existingDocument == null)
{
// Initialize the Version field
document.InitVersion();
// document does not exist
onPreExecuteWrite();
var task = Client.CreateDocumentAsync(Collection.SelfLink, document);
task.Wait();
}
else
{
// document does exist and we're going to check the version and replace if needed
document.SetVersion(VersionIncrementer.Increment(existingDocument.Version));
onPreExecuteWrite();
RequestOptions options = new RequestOptions
{
AccessCondition =
new AccessCondition
{
Type = AccessConditionType.IfMatch,
Condition = existingDocument.ETag
}
};
var task = Client.ReplaceDocumentAsync(existingDocument.SelfLink, document, options);
task.Wait();
}
return(new XCollectionResult());
});
// Send to the gate now!
_gateQueueWriter.Write(DocdbGatewayMessage.Create(_gatewayKey, document));
return(result);
}
protected virtual bool DispatchMessage(DocdbGatewayMessage message)
{
Guard.NotNull(message, "message");
Guard.NotNullOrEmpty(message.Key, "message.Key");
Guard.NotNull(message.Documents, "message.Documents");
// resolve key
string key = message.Key;
// Get target table and its storage account
if (!_cachedTargetCollections.ContainsKey(key))
{
_cachedTargetCollections[key] = _targetCollectionResolver.Resolve(key);
}
// TODO inserting multiple documents is not supported currently
// TODO or: a simple for-loop may be introduced here
XCollectionResult result = _cachedTargetCollections[key].Write(message.Documents[0]);
ProcessedMessagesCount++;
return(result.Discarded);
}
protected virtual void OnError(Exception exception, DocdbGatewayMessage message, CloudQueueMessage cloudMessage)
{
// TODO you can extend it to save the poisonous message
FaildedMessagesCount++;
}
