/// <summary>
/// Gets all existing queues through a series of asynchronous operations,
/// each of which requests a subset of the available queues.
/// </summary>
/// <param name="provider">The queueing service.</param>
/// <param name="limit">The maximum number of <see cref="CloudQueue"/> objects to return from a single task. If this value is <see langword="null"/>, a provider-specific default is used.</param>
/// <param name="detailed"><see langword="true"/> to return detailed information about each queue; otherwise, <see langword="false"/>.</param>
/// <param name="cancellationToken">The <see cref="CancellationToken"/> that the task will observe.</param>
/// <param name="progress">An optional callback object to receive progress notifications. If this is <see langword="null"/>, no progress notifications are sent.</param>
/// <returns>
/// A <see cref="Task"/> object representing the asynchronous operation. When the operation
/// completes successfully, the <see cref="Task{TResult}.Result"/> property will contain a
/// read-only collection containing the complete set of available queues.
/// </returns>
/// <exception cref="ArgumentNullException">If <paramref name="provider"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentOutOfRangeException">If <paramref name="limit"/> is less than or equal to 0.</exception>
private static async Task <ReadOnlyCollection <CloudQueue> > ListAllQueuesAsync(IQueueingService provider, int?limit, bool detailed, CancellationToken cancellationToken, net.openstack.Core.IProgress <ReadOnlyCollectionPage <CloudQueue> > progress)
{
if (provider == null)
{
throw new ArgumentNullException("provider");
}
if (limit <= 0)
{
throw new ArgumentOutOfRangeException("limit");
}
return(await(await provider.ListQueuesAsync(null, limit, detailed, cancellationToken)).GetAllPagesAsync(cancellationToken, progress));
}
/// <summary>
/// Gets all existing message queues through a series of asynchronous operations,
/// each of which requests a subset of the available queues.
/// </summary>
/// <remarks>
/// Each of the returned tasks is executed asynchronously but sequentially. This
/// method will not send concurrent requests to the queueing service.
/// <para>
/// Due to the way the list end is detected, the final task will return an empty
/// collection of <see cref="CloudQueue"/> instances.
/// </para>
/// </remarks>
/// <param name="provider">The queueing service.</param>
/// <param name="limit">The maximum number of <see cref="CloudQueue"/> to return from a single task. If this value is <c>null</c>, a provider-specific default is used.</param>
/// <param name="detailed"><c>true</c> to return detailed information for each queue; otherwise, <c>false</c>.</param>
/// <returns>
/// A collections of <see cref="Task{TResult}"/> objects, each of which
/// represents an asynchronous operation to gather a subset of the available
/// queues.
/// </returns>
private static IEnumerable<Task<IEnumerable<CloudQueue>>> ListAllQueuesAsync(IQueueingService provider, int? limit, bool detailed, CancellationToken cancellationToken)
{
if (limit <= 0)
throw new ArgumentOutOfRangeException("limit");
CloudQueue lastQueue = null;
do
{
QueueName marker = lastQueue != null ? lastQueue.Name : null;
Task<IEnumerable<CloudQueue>> queues = provider.ListQueuesAsync(marker, limit, detailed, cancellationToken);
lastQueue = null;
yield return queues.ContinueWith(task =>
{
return task.Result.Select(queue =>
{
lastQueue = queue;
return queue;
});
});
} while (lastQueue != null);
}
