/// <summary>initial the async batch save changeset</summary>
internal void BatchBeginRequest()
{
PerRequest pereq = null;
try
{
ODataRequestMessageWrapper batchRequestMessage = this.GenerateBatchRequest();
this.Abortable = batchRequestMessage;
if (batchRequestMessage != null)
{
batchRequestMessage.SetContentLengthHeader();
this.perRequest = pereq = new PerRequest();
pereq.Request = batchRequestMessage;
pereq.RequestContentStream = batchRequestMessage.CachedRequestStream;
AsyncStateBag asyncStateBag = new AsyncStateBag(pereq);
this.responseStream = new MemoryStream();
IAsyncResult asyncResult = BaseAsyncResult.InvokeAsync(batchRequestMessage.BeginGetRequestStream, this.AsyncEndGetRequestStream, asyncStateBag);
pereq.SetRequestCompletedSynchronously(asyncResult.CompletedSynchronously);
}
else
{
Debug.Assert(this.CompletedSynchronously, "completedSynchronously");
Debug.Assert(this.IsCompletedInternally, "completed");
}
}
catch (Exception e)
{
this.HandleFailure(pereq, e);
throw; // to user on BeginSaveChangeSet, will still invoke Callback
}
finally
{
this.HandleCompleted(pereq); // will invoke user callback
}
Debug.Assert((this.CompletedSynchronously && this.IsCompleted) || !this.CompletedSynchronously, "sync without complete");
}
internal void BeginCreateNextChange()
{
Debug.Assert(!this.IsCompletedInternally, "why being called if already completed?");
// create the memory stream required to cache the responses as we read async from the underlying http web response
this.inMemoryResponseStream = new MemoryStream();
// SaveCallback can't chain synchronously completed responses, caller will loop the to next change
PerRequest pereq = null;
IAsyncResult asyncResult = null;
do
{
IODataResponseMessage responseMsg = null;
ODataRequestMessageWrapper requestMessage = null;
try
{
if (this.perRequest != null)
{
this.SetCompleted();
Error.ThrowInternalError(InternalError.InvalidBeginNextChange);
}
requestMessage = this.CreateNextRequest();
// Keeping the old behavior (V1/V2) where the abortable was set to null,
// if CreateNextRequest returned null.
if (requestMessage == null)
{
this.Abortable = null;
}
if ((requestMessage != null) || (this.entryIndex < this.ChangedEntries.Count))
{
if (this.ChangedEntries[this.entryIndex].ContentGeneratedForSave)
{
Debug.Assert(this.ChangedEntries[this.entryIndex] is LinkDescriptor, "only expected RelatedEnd to presave");
Debug.Assert(
this.ChangedEntries[this.entryIndex].State == EntityStates.Added ||
this.ChangedEntries[this.entryIndex].State == EntityStates.Modified,
"only expected added to presave");
continue;
}
this.Abortable = requestMessage;
ContentStream contentStream = this.CreateNonBatchChangeData(this.entryIndex, requestMessage);
this.perRequest = pereq = new PerRequest();
pereq.Request = requestMessage;
AsyncStateBag asyncStateBag = new AsyncStateBag(pereq);
if (contentStream == null || contentStream.Stream == null)
{
asyncResult = BaseAsyncResult.InvokeAsync(requestMessage.BeginGetResponse, this.AsyncEndGetResponse, asyncStateBag);
}
else
{
if (contentStream.IsKnownMemoryStream)
{
requestMessage.SetContentLengthHeader();
}
pereq.RequestContentStream = contentStream;
asyncResult = BaseAsyncResult.InvokeAsync(requestMessage.BeginGetRequestStream, this.AsyncEndGetRequestStream, asyncStateBag);
}
pereq.SetRequestCompletedSynchronously(asyncResult.CompletedSynchronously);
this.SetCompletedSynchronously(pereq.RequestCompletedSynchronously);
}
else
{
this.SetCompleted();
if (this.CompletedSynchronously)
{
this.HandleCompleted(pereq);
}
}
}
catch (InvalidOperationException e)
{
e = WebUtil.GetHttpWebResponse(e, ref responseMsg);
this.HandleOperationException(e, responseMsg);
this.HandleCompleted(pereq);
}
finally
{
WebUtil.DisposeMessage(responseMsg);
}
// If the current request is completed synchronously, we need to call FinishCurrentChange() to process the response payload.
// FinishCurrentChange() will not call BeginCreateNextChange() when the request is synchronous.
// If the current request is completed asynchronously, an async thread will call FinishCurrentChange() to process the response payload.
// FinishCurrentchange() will then call BeginCreateNextChange() from the async thread and we need to exit this loop.
// If requestMessage = this.CreateNextRequest() returns null, we would have called this.SetCompleted() above and this.IsCompletedInternally
// would be true. This means we are done processing all changed entries and we should not call this.FinishCurrentChange().
if (pereq != null && pereq.RequestCompleted && pereq.RequestCompletedSynchronously && !this.IsCompletedInternally)
{
Debug.Assert(requestMessage != null, "httpWebRequest != null");
this.FinishCurrentChange(pereq);
}
// In the condition for the do-while loop we must test for pereq.RequestCompletedSynchronously and not asyncResult.CompletedSynchronously.
// pereq.RequestCompletedSynchronously is true only if all async calls completed synchronously. If we don't exit this loop when
// pereq.RequestCompletedSynchronously is false, the current thread and an async thread will both re-enter BeginCreateNextChange()
// and we will fail. We can only process one request at a given time.
}while (((pereq == null) || (pereq.RequestCompleted && pereq.RequestCompletedSynchronously)) && !this.IsCompletedInternally);
Debug.Assert((this.CompletedSynchronously && this.IsCompleted) || !this.CompletedSynchronously, "sync without complete");
Debug.Assert(this.entryIndex < this.ChangedEntries.Count || this.ChangedEntries.All(o => o.ContentGeneratedForSave), "didn't generate content for all entities/links");
}
