/// <inheritdoc/>
public Task <QueuedMessageList> ListMessagesAsync(QueueName queueName, QueuedMessageListId marker, int?limit, bool echo, bool includeClaimed, CancellationToken cancellationToken)
{
if (queueName == null)
{
throw new ArgumentNullException("queueName");
}
if (limit <= 0)
{
throw new ArgumentOutOfRangeException("limit");
}
UriTemplate template = new UriTemplate("/queues/{queue_name}/messages?marker={marker}&limit={limit}&echo={echo}&include_claimed={include_claimed}");
var parameters =
new Dictionary <string, string>()
{
{ "queue_name", queueName.Value },
{ "echo", echo.ToString() },
{ "include_claimed", includeClaimed.ToString() }
};
if (marker != null)
{
parameters["marker"] = marker.Value;
}
if (limit != null)
{
parameters["limit"] = limit.ToString();
}
Func <Task <Tuple <IdentityToken, Uri> >, HttpWebRequest> prepareRequest =
PrepareRequestAsyncFunc(HttpMethod.GET, template, parameters);
Func <Task <HttpWebRequest>, Task <ListCloudQueueMessagesResponse> > requestResource =
GetResponseAsyncFunc <ListCloudQueueMessagesResponse>(cancellationToken);
Func <Task <ListCloudQueueMessagesResponse>, QueuedMessageList> resultSelector =
task =>
{
ReadOnlyCollection <QueuedMessage> messages = null;
if (task.Result != null)
{
messages = task.Result.Messages;
}
QueuedMessageListId nextMarker = null;
if (task.Result != null && task.Result.Links != null)
{
Link nextLink = task.Result.Links.FirstOrDefault(i => string.Equals(i.Rel, "next", StringComparison.OrdinalIgnoreCase));
if (nextLink != null)
{
Uri baseUri = new Uri("https://example.com");
Uri absoluteUri;
if (nextLink.Href.StartsWith("/v1"))
{
absoluteUri = new Uri(baseUri, nextLink.Href.Substring("/v1".Length));
}
else
{
absoluteUri = new Uri(baseUri, nextLink.Href);
}
UriTemplateMatch match = template.Match(baseUri, absoluteUri);
if (!string.IsNullOrEmpty(match.BoundVariables["marker"]))
{
nextMarker = new QueuedMessageListId(match.BoundVariables["marker"]);
}
}
}
if (messages == null || messages.Count == 0)
{
// use the same marker again
messages = messages ?? new ReadOnlyCollection <QueuedMessage>(new QueuedMessage[0]);
nextMarker = marker;
}
Func <CancellationToken, Task <ReadOnlyCollectionPage <QueuedMessage> > > getNextPageAsync = null;
if (nextMarker != null || messages.Count == 0)
{
getNextPageAsync =
nextCancellationToken => ListMessagesAsync(queueName, nextMarker, limit, echo, includeClaimed, nextCancellationToken)
.Select(t => (ReadOnlyCollectionPage <QueuedMessage>)t.Result);
}
return(new QueuedMessageList(messages, getNextPageAsync, nextMarker));
};
return(AuthenticateServiceAsync(cancellationToken)
.Select(prepareRequest)
.Then(requestResource)
.Select(resultSelector));
}
/// <summary>
/// Gets a list of messages currently in a queue.
/// </summary>
/// <param name="queueingService">The queueing service instance.</param>
/// <param name="queueName">The queue name.</param>
/// <param name="marker">The identifier of the message list page to return. This is obtained from <see cref="QueuedMessageList.NextPageId"/>. If this value is <see langword="null"/>, the list starts at the beginning.</param>
/// <param name="limit">The maximum number of messages to return. If this value is <see langword="null"/>, a provider-specific default value is used.</param>
/// <param name="echo"><see langword="true"/> to include messages created by the current client; otherwise, <see langword="false"/>.</param>
/// <param name="includeClaimed"><see langword="true"/> to include claimed messages; otherwise <see langword="false"/> to return only unclaimed messages.</param>
/// <returns>A collection of <see cref="QueuedMessage"/> objects describing the messages in the queue.</returns>
/// <exception cref="ArgumentNullException">If <paramref name="queueingService"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentNullException">If <paramref name="queueName"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentOutOfRangeException">If <paramref name="limit"/> is less than or equal to 0.</exception>
/// <exception cref="WebException">If the REST request does not return successfully.</exception>
/// <seealso href="https://wiki.openstack.org/w/index.php?title=Marconi/specs/api/v1#List_Messages">List Messages (OpenStack Marconi API v1 Blueprint)</seealso>
public static QueuedMessageList ListMessages(this IQueueingService queueingService, QueueName queueName, QueuedMessageListId marker, int?limit, bool echo, bool includeClaimed)
{
if (queueingService == null)
{
throw new ArgumentNullException("queueingService");
}
try
{
return(queueingService.ListMessagesAsync(queueName, marker, limit, echo, includeClaimed, CancellationToken.None).Result);
}
catch (AggregateException ex)
{
ReadOnlyCollection <Exception> innerExceptions = ex.Flatten().InnerExceptions;
if (innerExceptions.Count == 1)
{
throw innerExceptions[0];
}
throw;
}
}
