/// <summary>
/// Reads an entry from the <paramref name="odataReader"/> and all it's children including expanded entries and feeds.
/// </summary>
/// <param name="odataReader">The ODataReader to read from.</param>
/// <param name="topLevelSegmentInfo">The segment info for the top-level entry to read.</param>
/// <returns>The <see cref="ODataEntry"/> with annotations which store the navigation links and their expanded values.</returns>
private ODataEntry ReadEntry(ODataReader odataReader, SegmentInfo topLevelSegmentInfo)
{
Debug.Assert(odataReader != null, "odataReader != null");
Debug.Assert(odataReader.State == ODataReaderState.Start, "The ODataReader must not have been used yet.");
Debug.Assert(topLevelSegmentInfo != null, "topLevelSegmentInfo != null");
ODataEntry topLevelEntry = null;
Stack <ODataItem> itemsStack = new Stack <ODataItem>();
while (odataReader.Read())
{
// Don't let the item stack grow larger than we can process later. Also lets us to fail and report the recursion depth limit error before ODL does.
if (itemsStack.Count >= RecursionLimit)
{
throw DataServiceException.CreateDeepRecursion(RecursionLimit);
}
switch (odataReader.State)
{
case ODataReaderState.EntryStart:
ODataEntry entry = (ODataEntry)odataReader.Item;
ODataEntryAnnotation entryAnnotation = null;
if (entry != null)
{
entryAnnotation = new ODataEntryAnnotation();
entry.SetAnnotation(entryAnnotation);
}
if (itemsStack.Count == 0)
{
Debug.Assert(entry != null, "The top-level entry can never be null.");
topLevelEntry = entry;
// For top-level entry, create the entry resource here.
// This is needed since the creation of the resource may fail (especially if this is an update in which case
// we evaluate the URL query, which may return no results and thus we would fail with 404)
// and we need to report that failure rather then potential other failures caused by the properties in the entry in question.
this.CreateEntityResource(topLevelSegmentInfo, entry, entryAnnotation, /*topLevel*/ true);
}
else
{
ODataItem parentItem = itemsStack.Peek();
ODataFeed parentFeed = parentItem as ODataFeed;
if (parentFeed != null)
{
ODataFeedAnnotation parentFeedAnnotation = parentFeed.GetAnnotation <ODataFeedAnnotation>();
Debug.Assert(parentFeedAnnotation != null, "Every feed we added to the stack should have the feed annotation on it.");
parentFeedAnnotation.Add(entry);
}
else
{
ODataNavigationLink parentNavigationLink = (ODataNavigationLink)parentItem;
ODataNavigationLinkAnnotation parentNavigationLinkAnnotation = parentNavigationLink.GetAnnotation <ODataNavigationLinkAnnotation>();
Debug.Assert(parentNavigationLinkAnnotation != null, "Every navigation link we added to the stack should have the navigation link annotation on it.");
Debug.Assert(parentNavigationLink.IsCollection == false, "Only singleton navigation properties can contain entry as their child.");
Debug.Assert(parentNavigationLinkAnnotation.Count == 0, "Each navigation property can contain only one entry as its direct child.");
parentNavigationLinkAnnotation.Add(entry);
}
}
itemsStack.Push(entry);
break;
case ODataReaderState.EntryEnd:
Debug.Assert(itemsStack.Count > 0 && itemsStack.Peek() == odataReader.Item, "The entry which is ending should be on the top of the items stack.");
itemsStack.Pop();
break;
case ODataReaderState.NavigationLinkStart:
ODataNavigationLink navigationLink = (ODataNavigationLink)odataReader.Item;
Debug.Assert(navigationLink != null, "Navigation link should never be null.");
navigationLink.SetAnnotation(new ODataNavigationLinkAnnotation());
Debug.Assert(itemsStack.Count > 0, "Navigation link can't appear as top-level item.");
{
ODataEntry parentEntry = (ODataEntry)itemsStack.Peek();
ODataEntryAnnotation parentEntryAnnotation = parentEntry.GetAnnotation <ODataEntryAnnotation>();
Debug.Assert(parentEntryAnnotation != null, "Every entry we added to the stack should have the navigation link annotation on it.");
parentEntryAnnotation.Add(navigationLink);
}
itemsStack.Push(navigationLink);
break;
case ODataReaderState.NavigationLinkEnd:
Debug.Assert(itemsStack.Count > 0 && itemsStack.Peek() == odataReader.Item, "The navigation link which is ending should be on the top of the items stack.");
itemsStack.Pop();
break;
case ODataReaderState.FeedStart:
ODataFeed feed = (ODataFeed)odataReader.Item;
Debug.Assert(feed != null, "Feed should never be null.");
feed.SetAnnotation(new ODataFeedAnnotation());
Debug.Assert(itemsStack.Count > 0, "Since we always start reading entry, we should never get a feed as the top-level item.");
{
ODataNavigationLink parentNavigationLink = (ODataNavigationLink)itemsStack.Peek();
ODataNavigationLinkAnnotation parentNavigationLinkAnnotation = parentNavigationLink.GetAnnotation <ODataNavigationLinkAnnotation>();
Debug.Assert(parentNavigationLinkAnnotation != null, "Every navigation link we added to the stack should have the navigation link annotation on it.");
Debug.Assert(parentNavigationLink.IsCollection == true, "Only collection navigation properties can contain feed as their child.");
parentNavigationLinkAnnotation.Add(feed);
}
itemsStack.Push(feed);
break;
case ODataReaderState.FeedEnd:
Debug.Assert(itemsStack.Count > 0 && itemsStack.Peek() == odataReader.Item, "The feed which is ending should be on the top of the items stack.");
itemsStack.Pop();
break;
case ODataReaderState.EntityReferenceLink:
ODataEntityReferenceLink entityReferenceLink = (ODataEntityReferenceLink)odataReader.Item;
Debug.Assert(entityReferenceLink != null, "Entity reference link should never be null.");
Debug.Assert(itemsStack.Count > 0, "Entity reference link should never be reported as top-level item.");
{
ODataNavigationLink parentNavigationLink = (ODataNavigationLink)itemsStack.Peek();
ODataNavigationLinkAnnotation parentNavigationLinkAnnotation = parentNavigationLink.GetAnnotation <ODataNavigationLinkAnnotation>();
Debug.Assert(parentNavigationLinkAnnotation != null, "Every navigation link we added to the stack should have the navigation link annotation on it.");
parentNavigationLinkAnnotation.Add(entityReferenceLink);
}
break;
default:
Debug.Assert(false, "We should never get here, it means the ODataReader reported a wrong state.");
break;
}
}
Debug.Assert(odataReader.State == ODataReaderState.Completed, "We should have consumed all of the input by now.");
Debug.Assert(topLevelEntry != null, "A top level entry should have been read by now.");
return(topLevelEntry);
}