/// <summary>
/// Checks whether the context payload is a partial collection of entrities
/// </summary>
/// <param name="context">The service context</param>
/// <returns>True if it is partial collection; false otherwise</returns>
private static bool IsPartialColleclection(ServiceContext context)
{
bool anyNewEntry = false;
JObject contextResponse = JsonParserHelper.GetResponseObject(context);
if (contextResponse != null)
{
JArray contextEntries = JsonParserHelper.GetEntries(contextResponse);
if (contextEntries.Count > 0)
{
// if any more entries return, the context response payload was a partial collection
Uri prober = FeedCore2001.ConstructProbeUri(context);
var resp = WebHelper.Get(prober, Constants.AcceptHeaderJson, RuleEngineSetting.Instance().DefaultMaximumPayloadSize, context.RequestHeaders);
if (resp == null || string.IsNullOrEmpty(resp.ResponsePayload) || !JsonHelper.IsJsonVerboseFeed(resp.ResponsePayload))
{
return(false);
}
JObject response = JsonParserHelper.GetResponseObject(resp.ResponsePayload);
if (response != null)
{
JArray entries = JsonParserHelper.GetEntries(response);
if (entries.Count > 0)
{
// some producers do not respect $skipton;
// need to look at each entry to see whether there is any new entry.
HashSet <string> contextEntryKeys = new HashSet <string>(EqualityComparer <string> .Default);
foreach (var e in contextEntries)
{
if (e.Type == JTokenType.Object)
{
var i = JsonParserHelper.GetTokenOfEntry((JObject)e);
contextEntryKeys.Add(i);
}
}
foreach (var e in entries)
{
if (e.Type == JTokenType.Object)
{
var i = JsonParserHelper.GetTokenOfEntry((JObject)e);
if (!contextEntryKeys.Contains(i))
{
anyNewEntry = true;
break;
}
}
}
}
}
}
}
return(anyNewEntry);
}
/// <summary>
/// Builds the uri for purpose of probing any remaining entries satisfying the request of service context
/// use the last entry's token in the feed as the marker of skiptoken;
/// and reduce the $top count if top was in context request URI.
/// </summary>
/// <param name="context">The service context object</param>
/// <returns>Uri object if a meaningful prober can be constructed; null otherwise </returns>
private static Uri ConstructProbeUri(ServiceContext context)
{
Uri result = null;
JObject response = JsonParserHelper.GetResponseObject(context);
if (response != null)
{
JArray entries = JsonParserHelper.GetEntries(response);
if (entries != null)
{
JObject lastEntry = JsonParserHelper.GetLastEntry(entries);
if (lastEntry != null)
{
string lastToken = JsonParserHelper.GetTokenOfEntry(lastEntry);
string lastTokenOfValues = ResourcePathHelper.GetValuesOfKey(lastToken);
var uri = context.Destination;
ResourcePathHelper pathHelper = new ResourcePathHelper(uri);
// replace top value with the reduced value, if $top was in context request
string topValue = pathHelper.GetQueryValue("$top");
if (!string.IsNullOrEmpty(topValue))
{
pathHelper.RemoveQueryOption("$top");
int entriesGot = entries.Count;
int entriesToGet;
if (Int32.TryParse(topValue, out entriesToGet) && entriesToGet > entriesGot)
{
int entriesLeft = entriesToGet - entriesGot;
pathHelper.AddQueryOption("$top", entriesLeft.ToString(CultureInfo.InvariantCulture));
}
}
// set up new skiptoken query
pathHelper.RemoveQueryOption("$skiptoken");
pathHelper.AddQueryOption("$skiptoken", lastTokenOfValues);
result = new Uri(pathHelper.Product);
}
}
}
return(result);
}