/// <summary>
/// Called by the CacheController when it wants this CacheRequest to be processed asynchronously.
/// </summary>
/// <param name="request">CacheRequest to be processed</param>
/// <param name="state">User state object</param>
/// <param name="cancellationToken"> </param>
public async Task<CacheRequestResult> ProcessCacheRequestAsync(CacheRequest request, object state,
CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
cancellationToken.ThrowIfCancellationRequested();
var wrapper = new AsyncArgsWrapper
{
UserPassedState = state,
CacheRequest = request,
Step = HttpState.Start
};
wrapper = await ProcessRequest(wrapper, cancellationToken);
CacheRequestResult cacheRequestResult;
if (wrapper.CacheRequest.RequestType == CacheRequestType.UploadChanges)
{
cacheRequestResult =
new CacheRequestResult(
wrapper.CacheRequest.RequestId,
wrapper.UploadResponse,
wrapper.CacheRequest.Changes.Count,
wrapper.Error,
wrapper.Step,
wrapper.UserPassedState);
}
else
{
cacheRequestResult =
new CacheRequestResult(
wrapper.CacheRequest.RequestId,
wrapper.DownloadResponse,
wrapper.Error,
wrapper.Step,
wrapper.UserPassedState);
}
return cacheRequestResult;
}
/// <summary>
/// Called by the CacheController when it wants this CacheRequest to be processed asynchronously.
/// </summary>
/// <param name="request">CacheRequest to be processed</param>
/// <param name="state">User state object</param>
public override void ProcessCacheRequestAsync(CacheRequest request, object state)
{
this._workerManager.AddWorkRequest(new AsyncWorkRequest(ProcessCacheRequestWorker, CacheRequestCompleted, request, state));
}
/// <summary>
/// Called by the CacheController when it wants this CacheRequest to be processed asynchronously.
/// </summary>
/// <param name="request">CacheRequest to be processed</param>
/// <param name="state">User state object</param>
public override void ProcessCacheRequestAsync(CacheRequest request, object state)
{
this._workerManager.AddWorkRequest(new AsyncWorkRequest(ProcessCacheRequestWorker, CacheRequestCompleted, request, state));
}
/// <summary> /// Method that will contain the actual implementation of the cache request processing. /// </summary> /// <param name="request">CacheRequest object</param> /// <param name="state">User state object</param> public abstract void ProcessCacheRequestAsync(CacheRequest request, object state);
/// <summary> /// Method that will contain the actual implementation of the cache request processing. /// </summary> /// <param name="request">CacheRequest object</param> /// <returns>ChangeSet for a dowload request or ChangeSetResponse for an upload request</returns> public abstract object ProcessCacheRequest(CacheRequest request);
/// <summary>
/// Method that performs a download. It gets the server blob anchor from the local provider and then creates an
/// CacheRequest object for that download request. It then passes the processing asynchronously to the underlying
/// CacheRequestHandler.
/// </summary>
private async Task <CacheRefreshStatistics> EnqueueDownloadRequest(CacheRefreshStatistics statistics,
CancellationToken cancellationToken,
IProgress <SyncProgressEvent> progress = null)
{
try
{
if (cancellationToken.IsCancellationRequested)
{
cancellationToken.ThrowIfCancellationRequested();
}
Boolean isLastBatch = false;
while (!isLastBatch)
{
if (cancellationToken.IsCancellationRequested)
{
cancellationToken.ThrowIfCancellationRequested();
}
// Create a SyncRequest for download.
CacheRequest request = new CacheRequest
{
Format = this.ControllerBehavior.SerializationFormat,
RequestType = CacheRequestType.DownloadChanges,
KnowledgeBlob = this.localProvider.GetServerBlob()
};
// Get Changes
DateTime durationStartDate = DateTime.Now;
var requestResult = await this.cacheRequestHandler.ProcessCacheRequestAsync(
request, null, cancellationToken);
statistics = await this.ProcessCacheRequestResults(statistics, requestResult, cancellationToken);
// Check if we are at the end
if (requestResult.ChangeSet == null || requestResult.ChangeSet.IsLastBatch)
{
isLastBatch = true;
}
// Reporting progress after get changes from local store
if (progress != null)
{
progress.Report(new SyncProgressEvent(SyncStage.DownloadingChanges, DateTime.Now.Subtract(durationStartDate), true, (requestResult.ChangeSet != null ? requestResult.ChangeSet.Data : null)));
}
}
}
catch (OperationCanceledException)
{
// Re throw the operation cancelled
throw;
}
catch (Exception e)
{
if (ExceptionUtility.IsFatal(e))
{
throw;
}
statistics.Error = e;
}
return(statistics);
}
/// <summary>
/// Method that performs an upload. It gets the ChangeSet from the local provider and then creates an
/// CacheRequest object for that ChangeSet and then passed the processing asynchronously to the underlying
/// CacheRequestHandler.
/// </summary>
private async Task <CacheRefreshStatistics> EnqueueUploadRequest(CacheRefreshStatistics statistics,
CancellationToken cancellationToken,
IProgress <SyncProgressEvent> progress = null)
{
this.changeSetId = Guid.NewGuid();
try
{
// Check if cancellation has occured
if (cancellationToken.IsCancellationRequested)
{
cancellationToken.ThrowIfCancellationRequested();
}
// Get Changes
DateTime durationStartDate = DateTime.Now;
ChangeSet changeSet = await this.localProvider.GetChangeSet(this.changeSetId);
// Reporting progress after get changes from local store
if (progress != null)
{
progress.Report(new SyncProgressEvent(SyncStage.GetChanges, DateTime.Now.Subtract(durationStartDate), true, (changeSet != null ? changeSet.Data : null)));
}
// No data to upload. Skip upload phase.
if (changeSet == null || changeSet.Data == null || changeSet.Data.Count == 0)
{
return(statistics);
}
// Create a SyncRequest out of this.
CacheRequest request = new CacheRequest
{
RequestId = this.changeSetId,
Format = this.ControllerBehavior.SerializationFormat,
RequestType = CacheRequestType.UploadChanges,
Changes = changeSet.Data,
KnowledgeBlob = changeSet.ServerBlob,
IsLastBatch = changeSet.IsLastBatch
};
// Upload changes to server
durationStartDate = DateTime.Now;
var requestResult = await this.cacheRequestHandler.ProcessCacheRequestAsync(
request, changeSet.IsLastBatch, cancellationToken);
// Get response from server if mb any conflicts or updated items
statistics = await this.ProcessCacheRequestResults(statistics, requestResult, cancellationToken);
// Reporting progress after uploading changes, and mb get back Conflicts and new Id from insterted items
if (progress != null)
{
progress.Report(new SyncProgressEvent(SyncStage.UploadingChanges, DateTime.Now.Subtract(durationStartDate), true,
changeSet.Data, requestResult.ChangeSetResponse.Conflicts, requestResult.ChangeSetResponse.UpdatedItems));
}
}
catch (OperationCanceledException)
{
// Re throw the operation cancelled
throw;
}
catch (Exception e)
{
if (ExceptionUtility.IsFatal(e))
{
throw;
}
statistics.Error = e;
}
return(statistics);
}
private object ProcessUploadRequest(HttpWebRequest webRequest, CacheRequest request)
{
using (Stream memoryStream = new MemoryStream())
{
// Create a SyncWriter to write the contents
this._syncWriter = new ODataAtomWriter(base.BaseUri);
this._syncWriter.StartFeed(true, request.KnowledgeBlob ?? new byte[0]);
foreach (IOfflineEntity entity in request.Changes)
{
// Skip tombstones that dont have a ID element.
if (entity.ServiceMetadata.IsTombstone && string.IsNullOrEmpty(entity.ServiceMetadata.Id))
{
continue;
}
string tempId = null;
// Check to see if this is an insert. i.e ServiceMetadata.Id is null or empty
if (string.IsNullOrEmpty(entity.ServiceMetadata.Id))
{
if (TempIdToEntityMapping == null)
{
TempIdToEntityMapping = new Dictionary <string, IOfflineEntity>();
}
tempId = Guid.NewGuid().ToString();
TempIdToEntityMapping.Add(tempId, entity);
}
this._syncWriter.AddItem(entity, tempId);
}
this._syncWriter.WriteFeed(XmlWriter.Create(memoryStream));
memoryStream.Flush();
// Set the content length
webRequest.ContentLength = memoryStream.Position;
using (Stream requestStream = webRequest.GetRequestStream())
{
CopyStreamContent(memoryStream, requestStream);
// Close the request stream
requestStream.Flush();
requestStream.Close();
}
}
// Fire the Before request handler
this.FirePreRequestHandler(webRequest);
// Get the response
HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();
if (webResponse.StatusCode == HttpStatusCode.OK)
{
ChangeSetResponse changeSetResponse = new ChangeSetResponse();
using (Stream responseStream = webResponse.GetResponseStream())
{
// Create the SyncReader
this._syncReader = new ODataAtomReader(responseStream, this._knownTypes);
// Read the response
while (this._syncReader.Next())
{
switch (this._syncReader.ItemType)
{
case ReaderItemType.Entry:
IOfflineEntity entity = this._syncReader.GetItem();
IOfflineEntity ackedEntity = entity;
string tempId = null;
// If conflict only one temp ID should be set
if (this._syncReader.HasTempId() && this._syncReader.HasConflictTempId())
{
throw new CacheControllerException(string.Format("Service returned a TempId '{0}' in both live and conflicting entities.",
this._syncReader.GetTempId()));
}
// Validate the live temp ID if any, before adding anything to the offline context
if (this._syncReader.HasTempId())
{
tempId = this._syncReader.GetTempId();
CheckEntityServiceMetadataAndTempIds(TempIdToEntityMapping, entity, tempId, changeSetResponse);
}
// If conflict
if (this._syncReader.HasConflict())
{
Conflict conflict = this._syncReader.GetConflict();
IOfflineEntity conflictEntity = (conflict is SyncConflict) ?
((SyncConflict)conflict).LosingEntity : ((SyncError)conflict).ErrorEntity;
// Validate conflict temp ID if any
if (this._syncReader.HasConflictTempId())
{
tempId = this._syncReader.GetConflictTempId();
CheckEntityServiceMetadataAndTempIds(TempIdToEntityMapping, conflictEntity, tempId, changeSetResponse);
}
// Add conflict
changeSetResponse.AddConflict(conflict);
//
// If there is a conflict and the tempId is set in the conflict entity then the client version lost the
// conflict and the live entity is the server version (ServerWins)
//
if (this._syncReader.HasConflictTempId() && entity.ServiceMetadata.IsTombstone)
{
//
// This is a ServerWins conflict, or conflict error. The winning version is a tombstone without temp Id
// so there is no way to map the winning entity with a temp Id. The temp Id is in the conflict so we are
// using the conflict entity, which has the PK, to build a tombstone entity used to update the offline context
//
// In theory, we should copy the service metadata but it is the same end result as the service fills in
// all the properties in the conflict entity
//
// Add the conflict entity
conflictEntity.ServiceMetadata.IsTombstone = true;
ackedEntity = conflictEntity;
}
}
// Add ackedEntity to storage. If ackedEntity is still equal to entity then add non-conflict entity.
if (!String.IsNullOrEmpty(tempId))
{
changeSetResponse.AddUpdatedItem(ackedEntity);
}
break;
case ReaderItemType.SyncBlob:
changeSetResponse.ServerBlob = this._syncReader.GetServerBlob();
break;
}
}
}
if (TempIdToEntityMapping != null && TempIdToEntityMapping.Count != 0)
{
// The client sent some inserts which werent ack'd by the service. Throw.
StringBuilder builder = new StringBuilder("Server did not acknowledge with a permanant Id for the following tempId's: ");
builder.Append(string.Join(",", TempIdToEntityMapping.Keys.ToArray()));
throw new CacheControllerException(builder.ToString());
}
this.FirePostResponseHandler(webResponse);
webResponse.Close();
return(changeSetResponse);
}
else
{
throw new CacheControllerException(
string.Format("Remote service returned error status. Status: {0}, Description: {1}",
webResponse.StatusCode,
webResponse.StatusDescription));
}
}
private object ProcessDownloadRequest(HttpWebRequest webRequest, CacheRequest request)
{
using (Stream memoryStream = new MemoryStream())
{
// Create a SyncWriter to write the contents
this._syncWriter = new ODataAtomWriter(base.BaseUri);
this._syncWriter.StartFeed(true, request.KnowledgeBlob ?? new byte[0]);
this._syncWriter.WriteFeed(XmlWriter.Create(memoryStream));
memoryStream.Flush();
webRequest.ContentLength = memoryStream.Position;
Stream requestStream = webRequest.GetRequestStream();
CopyStreamContent(memoryStream, requestStream);
requestStream.Flush();
requestStream.Close();
// Fire the Before request handler
this.FirePreRequestHandler(webRequest);
}
// Get the response
HttpWebResponse webResponse = (HttpWebResponse)webRequest.GetResponse();
if (webResponse.StatusCode == HttpStatusCode.OK)
{
ChangeSet changeSet = new ChangeSet();
using (Stream responseStream = webResponse.GetResponseStream())
{
// Create the SyncReader
this._syncReader = new ODataAtomReader(responseStream, this._knownTypes);
// Read the response
while (this._syncReader.Next())
{
switch (this._syncReader.ItemType)
{
case ReaderItemType.Entry:
changeSet.AddItem(this._syncReader.GetItem());
break;
case ReaderItemType.SyncBlob:
changeSet.ServerBlob = this._syncReader.GetServerBlob();
break;
case ReaderItemType.HasMoreChanges:
changeSet.IsLastBatch = !this._syncReader.GetHasMoreChangesValue();
break;
}
}
this.FirePostResponseHandler(webResponse);
}
webResponse.Close();
return(changeSet);
}
else
{
throw new CacheControllerException(
string.Format("Remote service returned error status. Status: {0}, Description: {1}",
webResponse.StatusCode,
webResponse.StatusDescription));
}
}
/// <summary> /// Method that will contain the actual implementation of the cache request processing. /// </summary> /// <param name="request">CacheRequest object</param> /// <param name="state">User state object</param> public abstract void ProcessCacheRequestAsync(CacheRequest request, object state);
/// <summary>
/// Method that performs a download. It gets the server blob anchor from the local provider and then creates an
/// CacheRequest object for that download request. It then passes the processing asynchronously to the underlying
/// CacheRequestHandler.
/// </summary>
void EnqueueDownloadRequest()
{
try
{
// Create a SyncRequest for download.
CacheRequest request = new CacheRequest()
{
Format = this.ControllerBehavior.SerializationFormat,
RequestType = CacheRequestType.DownloadChanges,
KnowledgeBlob = this.LocalProvider.GetServerBlob()
};
this._cacheRequestHandler.ProcessCacheRequestAsync(request, null /*state is null*/);
}
catch (Exception e)
{
if (ExceptionUtility.IsFatal(e))
{
throw;
}
// Error. EndSession refresh and post callback
CompleteAsyncWithException(e);
}
}
/// <summary>
/// Method that performs an upload. It gets the ChangeSet from the local provider and then creates an
/// CacheRequest object for that ChangeSet and then passed the processing asynchronously to the underlying
/// CacheRequestHandler.
/// </summary>
void EnqueueUploadRequest()
{
this.changeSetId = Guid.NewGuid();
try
{
ChangeSet changeSet = this._localProvider.GetChangeSet(this.changeSetId);
if (changeSet == null || changeSet.Data == null || changeSet.Data.Count == 0)
{
// No data to upload. Skip upload phase.
this.EnqueueDownloadRequest();
}
else
{
// Create a SyncRequest out of this.
CacheRequest request = new CacheRequest()
{
RequestId = this.changeSetId,
Format = this.ControllerBehavior.SerializationFormat,
RequestType = CacheRequestType.UploadChanges,
Changes = changeSet.Data,
KnowledgeBlob = changeSet.ServerBlob,
IsLastBatch = changeSet.IsLastBatch
};
this._cacheRequestHandler.ProcessCacheRequestAsync(request, changeSet.IsLastBatch /*state is the IsLastBatch flag*/);
}
}
catch (Exception e)
{
if (ExceptionUtility.IsFatal(e))
{
throw;
}
// Error. EndSession refresh and post callback
CompleteAsyncWithException(e);
}
}
/// <summary>
/// Method that refreshes the Cache by uploading all modified changes and then downloading the
/// server changes.
/// </summary>
/// <returns>A CacheRefreshStatistics object denoting the statistics from the Refresh call</returns>
public CacheRefreshStatistics Refresh()
{
this._controllerBehavior.Locked = true;
try
{
// First create the CacheRequestHandler
this._cacheRequestHandler = CacheRequestHandler.CreateRequestHandler(this._serviceUri, this._controllerBehavior);
CacheRefreshStatistics refreshStats = new CacheRefreshStatistics();
refreshStats.StartTime = DateTime.Now;
bool uploadComplete = false;
bool downloadComplete = false;
// Start sync by executin an Upload request
while (!uploadComplete || !downloadComplete)
{
if (!uploadComplete)
{
Guid changeSetId = Guid.NewGuid();
ChangeSet changeSet = this._localProvider.GetChangeSet(changeSetId);
if (changeSet.Data == null || changeSet.Data.Count == 0)
{
// No data to upload. Skip upload phase.
uploadComplete = true;
}
else
{
// Create a SyncRequest out of this.
CacheRequest request = new CacheRequest()
{
RequestId = changeSetId,
RequestType = CacheRequestType.UploadChanges,
Changes = changeSet.Data,
KnowledgeBlob = changeSet.ServerBlob,
IsLastBatch = changeSet.IsLastBatch
};
// Increment the stats
refreshStats.TotalChangeSetsUploaded++;
ChangeSetResponse response = (ChangeSetResponse)this._cacheRequestHandler.ProcessCacheRequest(request);
// Increment the stats
refreshStats.TotalUploads += (uint)request.Changes.Count;
response.ConflictsInternal.ForEach((e1) =>
{
if (e1 is SyncConflict)
{
refreshStats.TotalSyncConflicts++;
}
else
{
refreshStats.TotalSyncErrors++;
}
});
// Send the response to the local provider
this._localProvider.OnChangeSetUploaded(changeSetId, response);
uploadComplete = request.IsLastBatch;
}
}
else if (!downloadComplete)
{
// Create a SyncRequest for download.
CacheRequest request = new CacheRequest()
{
RequestType = CacheRequestType.DownloadChanges,
KnowledgeBlob = this.LocalProvider.GetServerBlob()
};
ChangeSet changeSet = (ChangeSet)this._cacheRequestHandler.ProcessCacheRequest(request);
// Increment the refresh stats
refreshStats.TotalChangeSetsDownloaded++;
refreshStats.TotalDownloads += (uint)changeSet.Data.Count;
// Call the SaveChangeSet method on local provider.
this.LocalProvider.SaveChangeSet(changeSet);
downloadComplete = changeSet.IsLastBatch;
}
}
refreshStats.EndTime = DateTime.Now;
// Finally return the statistics object
return(refreshStats);
}
finally
{
// Unlock the ControllerBehavior object
this._controllerBehavior.Locked = false;
}
}
/// <summary>
/// Method that performs a download. It gets the server blob anchor from the local provider and then creates an
/// CacheRequest object for that download request. It then passes the processing asynchronously to the underlying
/// CacheRequestHandler.
/// </summary>
private async Task<CacheRefreshStatistics> EnqueueDownloadRequest(CacheRefreshStatistics statistics,
CancellationToken cancellationToken,
IProgress<SyncProgressEvent> progress = null)
{
try
{
if (cancellationToken.IsCancellationRequested)
cancellationToken.ThrowIfCancellationRequested();
Boolean isLastBatch = false;
while (!isLastBatch)
{
if (cancellationToken.IsCancellationRequested)
cancellationToken.ThrowIfCancellationRequested();
// Create a SyncRequest for download.
CacheRequest request = new CacheRequest
{
Format = this.ControllerBehavior.SerializationFormat,
RequestType = CacheRequestType.DownloadChanges,
KnowledgeBlob = this.localProvider.GetServerBlob()
};
// Get Changes
DateTime durationStartDate = DateTime.Now;
var args = await this.cacheRequestHandler.ProcessCacheRequestAsync(request, null, cancellationToken);
statistics = await this.ProcessCacheRequestResults(statistics, args, cancellationToken);
// Check if we are at the end
if (args.ChangeSet == null || args.ChangeSet.IsLastBatch)
isLastBatch = true;
// Reporting progress after get changes from local store
if (progress != null)
progress.Report(new SyncProgressEvent(SyncStage.DownloadingChanges, DateTime.Now.Subtract(durationStartDate), true, (args.ChangeSet != null ? args.ChangeSet.Data : null)));
}
}
catch (OperationCanceledException)
{
// Re throw the operation cancelled
throw;
}
catch (Exception e)
{
if (ExceptionUtility.IsFatal(e))
throw;
statistics.Error = e;
}
return statistics;
}
/// <summary>
/// Method that performs an upload. It gets the ChangeSet from the local provider and then creates an
/// CacheRequest object for that ChangeSet and then passed the processing asynchronously to the underlying
/// CacheRequestHandler.
/// </summary>
private async Task<CacheRefreshStatistics> EnqueueUploadRequest(CacheRefreshStatistics statistics,
CancellationToken cancellationToken,
IProgress<SyncProgressEvent> progress = null)
{
this.changeSetId = Guid.NewGuid();
try
{
// Check if cancellation has occured
if (cancellationToken.IsCancellationRequested)
cancellationToken.ThrowIfCancellationRequested();
// Get Changes
DateTime durationStartDate = DateTime.Now;
ChangeSet changeSet = await this.localProvider.GetChangeSet(this.changeSetId);
// Reporting progress after get changes from local store
if (progress != null)
progress.Report(new SyncProgressEvent(SyncStage.GetChanges, DateTime.Now.Subtract(durationStartDate), true, (changeSet != null ? changeSet.Data : null)));
// No data to upload. Skip upload phase.
if (changeSet == null || changeSet.Data == null || changeSet.Data.Count == 0)
return statistics;
// Create a SyncRequest out of this.
CacheRequest request = new CacheRequest
{
RequestId = this.changeSetId,
Format = this.ControllerBehavior.SerializationFormat,
RequestType = CacheRequestType.UploadChanges,
Changes = changeSet.Data,
KnowledgeBlob = changeSet.ServerBlob,
IsLastBatch = changeSet.IsLastBatch
};
// Upload changes to server
durationStartDate = DateTime.Now;
var args = await this.cacheRequestHandler.ProcessCacheRequestAsync(request, changeSet.IsLastBatch, cancellationToken);
// Get response from server if mb any conflicts or updated items
statistics = await this.ProcessCacheRequestResults(statistics, args, cancellationToken);
// Reporting progress after uploading changes, and mb get back Conflicts and new Id from insterted items
if (progress != null)
progress.Report(new SyncProgressEvent(SyncStage.UploadingChanges, DateTime.Now.Subtract(durationStartDate), true,
changeSet.Data, args.ChangeSetResponse.Conflicts, args.ChangeSetResponse.UpdatedItems));
}
catch (OperationCanceledException)
{
// Re throw the operation cancelled
throw;
}
catch (Exception e)
{
if (ExceptionUtility.IsFatal(e))
throw;
statistics.Error = e;
}
return statistics;
}
