private ServerEndPoint FindSlave(ServerEndPoint endpoint, RedisCommand command)
{
if (endpoint.IsSlave && endpoint.IsSelectable(command))
{
return(endpoint);
}
var slaves = endpoint.Slaves;
for (int i = 0; i < slaves.Length; i++)
{
endpoint = slaves[i];
if (endpoint.IsSlave && endpoint.IsSelectable(command))
{
return(endpoint);
}
}
return(null);
}
private ServerEndPoint FindSlave(ServerEndPoint endpoint, RedisCommand command, bool allowDisconnected = false)
{
if (endpoint.IsSlave && endpoint.IsSelectable(command, allowDisconnected))
{
return(endpoint);
}
var slaves = endpoint.Slaves;
var len = slaves.Length;
uint startOffset = len <= 1 ? 0 : endpoint.NextReplicaOffset();
for (int i = 0; i < len; i++)
{
endpoint = slaves[(int)(((uint)i + startOffset) % len)];
if (endpoint.IsSlave && endpoint.IsSelectable(command, allowDisconnected))
{
return(endpoint);
}
}
return(null);
}
private ServerEndPoint FindMaster(ServerEndPoint endpoint, RedisCommand command)
{
int max = 5;
do
{
if (!endpoint.IsSlave && endpoint.IsSelectable(command))
{
return(endpoint);
}
endpoint = endpoint.Master;
} while (endpoint != null && --max != 0);
return(null);
}
private ServerEndPoint Select(int slot, RedisCommand command, CommandFlags flags)
{
flags = Message.GetMasterSlaveFlags(flags); // only intersted in master/slave preferences
ServerEndPoint[] arr;
if (slot == NoSlot || (arr = map) == null)
{
return(Any(command, flags));
}
ServerEndPoint endpoint = arr[slot], testing;
// but: ^^^ is the MASTER slots; if we want a slave, we need to do some thinking
if (endpoint != null)
{
switch (flags)
{
case CommandFlags.DemandSlave:
return(FindSlave(endpoint, command) ?? Any(command, flags));
case CommandFlags.PreferSlave:
testing = FindSlave(endpoint, command);
if (testing != null)
{
return(testing);
}
break;
case CommandFlags.DemandMaster:
return(FindMaster(endpoint, command) ?? Any(command, flags));
case CommandFlags.PreferMaster:
testing = FindMaster(endpoint, command);
if (testing != null)
{
return(testing);
}
break;
}
if (endpoint.IsSelectable(command))
{
return(endpoint);
}
}
return(Any(command, flags));
}
private ServerEndPoint FindSlave(ServerEndPoint endpoint, RedisCommand command)
{
if (endpoint.IsSlave && endpoint.IsSelectable(command)) return endpoint;
var slaves = endpoint.Slaves;
for (int i = 0; i < slaves.Length; i++)
{
endpoint = slaves[i];
if (endpoint.IsSlave && endpoint.IsSelectable(command)) return endpoint;
}
return null;
}
private ServerEndPoint FindMaster(ServerEndPoint endpoint, RedisCommand command)
{
int max = 5;
do
{
if (!endpoint.IsSlave && endpoint.IsSelectable(command)) return endpoint;
endpoint = endpoint.Master;
} while (endpoint != null && --max != 0);
return null;
}
public bool TryResend(int hashSlot, Message message, EndPoint endpoint, bool isMoved)
{
try
{
if (serverType == ServerType.Standalone || hashSlot < 0 || hashSlot >= RedisClusterSlotCount)
{
return(false);
}
ServerEndPoint server = multiplexer.GetServerEndPoint(endpoint);
if (server != null)
{
bool retry = false;
if ((message.Flags & CommandFlags.NoRedirect) == 0)
{
message.SetAsking(!isMoved);
message.SetNoRedirect(); // once is enough
// note that everything so far is talking about MASTER nodes; we might be
// wanting a SLAVE, so we'll check
ServerEndPoint resendVia = null;
var command = message.Command;
switch (Message.GetMasterSlaveFlags(message.Flags))
{
case CommandFlags.DemandMaster:
resendVia = server.IsSelectable(command) ? null : server;
break;
case CommandFlags.PreferMaster:
resendVia = server.IsSelectable(command) ? FindSlave(server, command) : server;
break;
case CommandFlags.PreferSlave:
resendVia = FindSlave(server, command) ?? (server.IsSelectable(command) ? null : server);
break;
case CommandFlags.DemandSlave:
resendVia = FindSlave(server, command);
break;
}
if (resendVia == null)
{
multiplexer.Trace("Unable to resend to " + endpoint);
}
else
{
message.PrepareToResend(resendVia, isMoved);
retry = resendVia.TryEnqueue(message);
}
}
if (isMoved) // update map; note we can still update the map even if we aren't actually goint to resend
{
var arr = MapForMutation();
var oldServer = arr[hashSlot];
arr[hashSlot] = server;
if (oldServer != server)
{
multiplexer.OnHashSlotMoved(hashSlot, oldServer == null ? null : oldServer.EndPoint, endpoint);
}
}
return(retry);
}
return(false);
}
catch
{
return(false);
}
}
