/// <summary>
/// Creates an Event Hub consumer responsible for reading <see cref="EventData" /> from a specific Event Hub partition,
/// and as a member of a specific consumer group.
///
/// A consumer may be exclusive, which asserts ownership over the partition for the consumer
/// group to ensure that only one consumer from that group is reading the from the partition.
/// These exclusive consumers are sometimes referred to as "Epoch Consumers."
///
/// A consumer may also be non-exclusive, allowing multiple consumers from the same consumer
/// group to be actively reading events from the partition. These non-exclusive consumers are
/// sometimes referred to as "Non-epoch Consumers."
///
/// Designating a consumer as exclusive may be specified in the <paramref name="consumerOptions" />.
/// By default, consumers are created as non-exclusive.
/// </summary>
///
/// <param name="partitionId">The identifier of the Event Hub partition from which events will be received.</param>
/// <param name="eventPosition">The position within the partition where the consumer should begin reading events.</param>
/// <param name="consumerOptions">The set of options to apply when creating the consumer.</param>
///
/// <returns>An Event Hub consumer configured in the requested manner.</returns>
///
public virtual EventHubConsumer CreateConsumer(string partitionId,
EventPosition eventPosition,
EventHubConsumerOptions consumerOptions = default)
{
Guard.ArgumentNotNullOrEmpty(nameof(partitionId), partitionId);
Guard.ArgumentNotNull(nameof(eventPosition), eventPosition);
var options = consumerOptions?.Clone() ?? new EventHubConsumerOptions {
Retry = null, DefaultMaximumReceiveWaitTime = null
};
options.Retry = options.Retry ?? ClientOptions.Retry.Clone();
options.DefaultMaximumReceiveWaitTime = options.MaximumReceiveWaitTimeOrDefault ?? ClientOptions.DefaultTimeout;
return(InnerClient.CreateConsumer(partitionId, eventPosition, options));
}
/// <summary>
/// Initializes a new instance of the <see cref="EventHubConsumer"/> class.
/// </summary>
///
/// <param name="transportConsumer">An abstracted Event Consumer specific to the active protocol and transport intended to perform delegated operations.</param>
/// <param name="eventHubPath">The path of the Event Hub from which events will be received.</param>
/// <param name="partitionId">The identifier of the Event Hub partition from which events will be received.</param>
/// <param name="eventPosition">The position within the partition where the consumer should begin reading events.</param>
/// <param name="consumerOptions">The set of options to use for this consumer.</param>
///
/// <remarks>
/// If the starting event position is not specified in the <paramref name="consumerOptions"/>, the consumer will
/// default to ignoring events in the partition that were queued prior to the consumer being created and read only
/// events which appear after that point.
///
/// Because this is a non-public constructor, it is assumed that the <paramref name="consumerOptions" /> passed are
/// owned by this instance and are safe from changes made by consumers. It is considered the responsibility of the
/// caller to ensure that any needed cloning of options is performed.
/// </remarks>
///
internal EventHubConsumer(TransportEventHubConsumer transportConsumer,
string eventHubPath,
string partitionId,
EventPosition eventPosition,
EventHubConsumerOptions consumerOptions)
{
Guard.ArgumentNotNull(nameof(transportConsumer), transportConsumer);
Guard.ArgumentNotNullOrEmpty(nameof(eventHubPath), eventHubPath);
Guard.ArgumentNotNullOrEmpty(nameof(partitionId), partitionId);
Guard.ArgumentNotNull(nameof(eventPosition), eventPosition);
Guard.ArgumentNotNull(nameof(consumerOptions), consumerOptions);
PartitionId = partitionId;
StartingPosition = eventPosition;
OwnerLevel = consumerOptions.OwnerLevel;
ConsumerGroup = consumerOptions.ConsumerGroup;
Options = consumerOptions;
InnerConsumer = transportConsumer;
}
