/// <inheritdoc/>
public void SendRequest(Exchange exchange, Request request)
{
if (request.ID == Message.None)
{
request.ID = System.Threading.Interlocked.Increment(ref _currentID) % (1 << 16);
}
/*
* The request is a CON or NON and must be prepared for these responses
* - CON => ACK / RST / ACK+response / CON+response / NON+response
* - NON => RST / CON+response / NON+response
* If this request goes lost, we do not get anything back.
*/
// the MID is from the local namespace -- use blank address
Exchange.KeyID keyID = new Exchange.KeyID(request.ID, null, request.Session);
// If we do not have a token, then create one
Exchange.KeyToken keyToken;
if (request.Token == null)
{
int length = _tokenLength;
if (_tokenLength < 0)
{
length = _random.Next(8);
}
byte[] token = new byte[length];
int tries = 0;
do
{
if ((length < 8) && (tries > length * 5 + 1))
{
length += 1;
tries = 0;
token = new byte[length];
}
_random.NextBytes(token);
keyToken = new Exchange.KeyToken(token);
} while (_exchangesByToken.ContainsKey(keyToken));
request.Token = token;
}
else
{
keyToken = new Exchange.KeyToken(request.Token);
}
exchange.Completed += OnExchangeCompleted;
_Log.Debug(m => m("Stored open request by {0}, {1}", keyID, keyToken));
_exchangesByID[keyID] = exchange;
_exchangesByToken[keyToken] = exchange;
}
private void OnExchangeCompleted(Object sender, EventArgs e)
{
Exchange exchange = (Exchange)sender;
/*
* Logging in this method leads to significant performance loss.
* Uncomment logging code only for debugging purposes.
*/
if (exchange.Origin == Origin.Local)
{
// this endpoint created the Exchange by issuing a request
Exchange.KeyID keyID = new Exchange.KeyID(exchange.CurrentRequest.ID, null, null);
Exchange.KeyToken keyToken = new Exchange.KeyToken(exchange.CurrentRequest.Token);
if (_Log.IsDebugEnabled)
{
_Log.Debug("Exchange completed: Cleaning up " + keyToken);
}
_exchangesByToken.Remove(keyToken);
// in case an empty ACK was lost
_exchangesByID.Remove(keyID);
}
else // Origin.Remote
{
// this endpoint created the Exchange to respond a request
Response response = exchange.CurrentResponse;
if (response != null && response.Type != MessageType.ACK)
{
// only response MIDs are stored for ACK and RST, no reponse Tokens
Exchange.KeyID midKey = new Exchange.KeyID(response.ID, null, response.Session);
//if (log.IsDebugEnabled)
// log.Debug("Remote ongoing completed, cleaning up " + midKey);
_exchangesByID.Remove(midKey);
}
Request request = exchange.CurrentRequest;
if (request != null && (request.HasOption(OptionType.Block1) || response.HasOption(OptionType.Block2)))
{
Exchange.KeyUri uriKey = new Exchange.KeyUri(request, request.Source);
_Log.Debug(m => m($"Remote ongoing completed, cleaning up {uriKey}"));
Exchange exc;
_ongoingExchanges.TryRemove(uriKey, out exc);
}
// Remove all remaining NON-notifications if this exchange is an observe relation
ObserveRelation relation = exchange.Relation;
if (relation != null)
{
RemoveNotificatoinsOf(relation);
}
}
}
/// <inheritdoc/>
public Exchange ReceiveResponse(Response response)
{
/*
* This response could be
* - The first CON/NON/ACK+response => deliver
* - Retransmitted CON (because client got no ACK)
* => resend ACK
*/
Exchange.KeyID keyId;
if (response.Type == MessageType.ACK)
{
// own namespace
keyId = new Exchange.KeyID(response.ID, null, response.Session);
}
else
{
// remote namespace
keyId = new Exchange.KeyID(response.ID, response.Source, response.Session);
}
Exchange.KeyToken keyToken = new Exchange.KeyToken(response.Token);
Exchange exchange;
if (_exchangesByToken.TryGetValue(keyToken, out exchange))
{
// We need to play games if this is multicast
if (exchange.CurrentRequest.IsMulticast)
{
Exchange newExchange = new Exchange(exchange);
newExchange.Request = exchange.Request;
exchange = newExchange;
}
// There is an exchange with the given token
Exchange prev = _deduplicator.FindPrevious(keyId, exchange);
if (prev != null)
{
// (and thus it holds: prev == exchange)
_Log.Info(m => m($"Duplicate response for open exchange: {response}"));
response.Duplicate = true;
}
else
{
keyId = new Exchange.KeyID(exchange.CurrentRequest.ID, null, response.Session);
_Log.Debug(m => m($"Exchange got response: Cleaning up {keyId}"));
_exchangesByID.Remove(keyId);
}
if (response.Type == MessageType.ACK && exchange.CurrentRequest.ID != response.ID)
{
// The token matches but not the MID. This is a response for an older exchange
_Log.Warn(m => m($"Possible MID reuse before lifetime end: {response.TokenString} expected MID {exchange.CurrentRequest.ID} but received {response.ID}"));
}
return(exchange);
}
else
{
// There is no exchange with the given token.
if (response.Type != MessageType.ACK)
{
// only act upon separate responses
Exchange prev = _deduplicator.Find(keyId);
if (prev != null)
{
_Log.Info(m => m($"Duplicate response for completed exchange: {response}"));
response.Duplicate = true;
return(prev);
}
}
else
{
_Log.Info(m => m($"Ignoring unmatchable piggy-backed response from {response.Source}: {response}"));
}
// ignore response
return(null);
}
}
/// <inheritdoc/>
public Exchange ReceiveResponse(Response response)
{
/*
* This response could be
* - The first CON/NON/ACK+response => deliver
* - Retransmitted CON (because client got no ACK)
* => resend ACK
*/
Exchange.KeyID keyId;
if (response.Type == MessageType.ACK)
{
// own namespace
keyId = new Exchange.KeyID(response.ID, null, response.Session);
}
else
{
// remote namespace
keyId = new Exchange.KeyID(response.ID, response.Source, response.Session);
}
Exchange.KeyToken keyToken = new Exchange.KeyToken(response.Token);
Exchange exchange;
if (_exchangesByToken.TryGetValue(keyToken, out exchange))
{
// There is an exchange with the given token
Exchange prev = _deduplicator.FindPrevious(keyId, exchange);
if (prev != null)
{
// (and thus it holds: prev == exchange)
if (_Log.IsInfoEnabled)
{
_Log.Info("Duplicate response for open exchange: " + response);
}
response.Duplicate = true;
}
else
{
keyId = new Exchange.KeyID(exchange.CurrentRequest.ID, null, response.Session);
if (_Log.IsDebugEnabled)
{
_Log.Debug("Exchange got response: Cleaning up " + keyId);
}
_exchangesByID.Remove(keyId);
}
if (response.Type == MessageType.ACK && exchange.CurrentRequest.ID != response.ID)
{
// The token matches but not the MID. This is a response for an older exchange
if (_Log.IsWarnEnabled)
{
_Log.Warn("Possible MID reuse before lifetime end: " + response.TokenString + " expected MID " + exchange.CurrentRequest.ID + " but received " + response.ID);
}
}
return(exchange);
}
else
{
// There is no exchange with the given token.
if (response.Type != MessageType.ACK)
{
// only act upon separate responses
Exchange prev = _deduplicator.Find(keyId);
if (prev != null)
{
if (_Log.IsInfoEnabled)
{
_Log.Info("Duplicate response for completed exchange: " + response);
}
response.Duplicate = true;
return(prev);
}
}
else
{
if (_Log.IsInfoEnabled)
{
_Log.Info("Ignoring unmatchable piggy-backed response from " + response.Source + ": " + response);
}
}
// ignore response
return(null);
}
}
