public async Task<ReceivingAmqpLink> CreateReceivingLinkAsync(
string path,
IotHubConnectionString connectionString,
string corrId,
ReceivingLinkType linkType,
uint prefetchCount,
TimeSpan timeout,
ProductInfo productInfo,
CancellationToken cancellationToken)
{
this.OnCreateReceivingLink(connectionString);
var timeoutHelper = new TimeoutHelper(timeout);
AmqpSession session = await this.GetSessionAsync(timeoutHelper, cancellationToken).ConfigureAwait(false);
var linkAddress = this.BuildLinkAddress(connectionString, path);
var linkSettings = new AmqpLinkSettings()
{
Role = true,
TotalLinkCredit = prefetchCount,
AutoSendFlow = prefetchCount > 0,
Source = new Source() { Address = linkAddress.AbsoluteUri },
LinkName = Guid.NewGuid().ToString("N") // Use a human readable link name to help with debuggin
};
switch (linkType)
{
// Exactly once
case ReceivingLinkType.C2DMessages:
linkSettings.SndSettleMode = null; // SenderSettleMode.Unsettled (null as it is the default and to avoid bytes on the wire)
linkSettings.RcvSettleMode = (byte)ReceiverSettleMode.Second;
break;
// At least once
case ReceivingLinkType.Events:
linkSettings.SndSettleMode = null; // SenderSettleMode.Unsettled (null as it is the default and to avoid bytes on the wire)
linkSettings.RcvSettleMode = (byte)ReceiverSettleMode.First;
break;
// At most once
case ReceivingLinkType.Methods:
case ReceivingLinkType.Twin:
linkSettings.SndSettleMode = (byte)SenderSettleMode.Settled;
linkSettings.RcvSettleMode = (byte)ReceiverSettleMode.First;
break;
}
SetLinkSettingsCommonProperties(linkSettings, timeoutHelper.RemainingTime(), productInfo);
if (linkType == ReceivingLinkType.Methods)
{
SetLinkSettingsCommonPropertiesForMethod(linkSettings, corrId);
}
else if (linkType == ReceivingLinkType.Twin)
{
SetLinkSettingsCommonPropertiesForTwin(linkSettings, corrId);
}
var link = new ReceivingAmqpLink(linkSettings);
link.AttachTo(session);
var audience = this.BuildAudience(connectionString, path);
await this.OpenLinkAsync(link, connectionString, audience, timeoutHelper.RemainingTime(), cancellationToken).ConfigureAwait(false);
return link;
}
protected static AmqpLinkSettings SetLinkSettingsCommonProperties(AmqpLinkSettings linkSettings, TimeSpan timeSpan, ProductInfo productInfo)
{
linkSettings.AddProperty(IotHubAmqpProperty.TimeoutName, timeSpan.TotalMilliseconds);
linkSettings.AddProperty(IotHubAmqpProperty.ClientVersion, productInfo.ToString());
return linkSettings;
}
public async Task <SendingAmqpLink> CreateSendingLinkAsync(
string path,
IotHubConnectionString connectionString,
string corrId,
SendingLinkType linkType,
TimeSpan timeout,
ProductInfo productInfo,
CancellationToken cancellationToken)
{
try
{
if (Logging.IsEnabled)
{
Logging.Enter(this, corrId, linkType, $"{nameof(IotHubConnection)}.{nameof(CreateSendingLinkAsync)}");
}
this.OnCreateSendingLink(connectionString);
var timeoutHelper = new TimeoutHelper(timeout);
AmqpSession session = await this.GetSessionAsync(timeoutHelper, cancellationToken).ConfigureAwait(false);
var linkAddress = this.BuildLinkAddress(connectionString, path);
var linkSettings = new AmqpLinkSettings()
{
Role = false,
InitialDeliveryCount = 0,
Target = new Target()
{
Address = linkAddress.AbsoluteUri
},
LinkName = Guid.NewGuid().ToString("N") // Use a human readable link name to help with debugging
};
switch (linkType)
{
case SendingLinkType.TelemetryEvents:
linkSettings.SndSettleMode = null; // SenderSettleMode.Unsettled (null as it is the default and to avoid bytes on the wire)
linkSettings.RcvSettleMode = null; // (byte)ReceiverSettleMode.First (null as it is the default and to avoid bytes on the wire)
break;
case SendingLinkType.Methods:
case SendingLinkType.Twin:
linkSettings.SndSettleMode = (byte)SenderSettleMode.Settled;
linkSettings.RcvSettleMode = (byte)ReceiverSettleMode.First;
break;
}
SetLinkSettingsCommonProperties(linkSettings, timeoutHelper.RemainingTime(), productInfo);
if (linkType == SendingLinkType.Methods)
{
SetLinkSettingsCommonPropertiesForMethod(linkSettings, corrId);
}
else if (linkType == SendingLinkType.Twin)
{
SetLinkSettingsCommonPropertiesForTwin(linkSettings, corrId);
}
var link = new SendingAmqpLink(linkSettings);
link.AttachTo(session);
var audience = this.BuildAudience(connectionString, path);
await this.OpenLinkAsync(link, connectionString, audience, timeoutHelper.RemainingTime(), cancellationToken).ConfigureAwait(false);
return(link);
}
finally
{
if (Logging.IsEnabled)
{
Logging.Exit(this, corrId, linkType, $"{nameof(IotHubConnection)}.{nameof(CreateSendingLinkAsync)}");
}
}
}
