[occ] Clarified upstream, channel creation workaround still needed

This reverts commit 283deff.

Author: teo

occ/plugin/OccPluginServer.cxx

@@ -307,6 +307,49 @@ OccPluginServer::Transition(grpc::ServerContext* context,
 
     try {
         auto evt = fair::mq::PluginServices::ToDeviceStateTransition(event);
+
+        // FIXME: big ugly workaround over here
+        // Since FairMQ currently (11/2018) can't yet implicitly create channels when receiving
+        // chans.* properties during INITIALIZING DEVICE, we must fake a --channel-config cli
+        // parameter during INIT and before the INIT DEVICE event.
+        // We extract channel related properties from the OCC transition arguments vector and we
+        // build up a vector of strings which mimics stuff along the lines of
+        //    --channel-config name=data,type=push,method=bind,address=tcp://*:5555,rateLogging=0"
+        // See https://github.com/FairRootGroup/FairMQ/pull/111
+        // When the relevant FairMQ 1.4.x version implements implicit channel creation, this whole
+        // block should be removed with no loss of functionality.
+        if (evt == fair::mq::PluginServices::DeviceStateTransition::InitDevice) {
+            std::unordered_map<std::string, std::unordered_map<std::string, std::string>> channels;
+            for (auto it = arguments.cbegin(); it != arguments.cend(); ++it) {
+                auto key = it->key();
+                if (boost::starts_with(key, "chans.")) {
+                    key.erase(0, 6);
+                    std::vector<std::string> split;
+                    boost::split(split, key, std::bind1st(std::equal_to<char>(), '.'));
+                    if (split.size() != 3)
+                        continue;
+                    auto name = split[0];
+                    auto propKey = split[2];
+                    if (channels.find(name) == channels.end()) // if map for this chan doesn't exist yet
+                        channels[name] = std::unordered_map<std::string, std::string>();
+                    channels[name][propKey] = it->value();
+                }
+            }
+
+            std::vector<std::string> channelLines;
+            for (auto it = channels.cbegin(); it != channels.cend(); ++it) {
+                std::vector<std::string> line;
+                line.push_back("name=" + it->first);
+                for (auto jt = it->second.cbegin(); jt != it->second.cend(); ++jt) {
+                    line.push_back(jt->first + "=" + jt->second);
+                }
+                channelLines.push_back(boost::join(line, ","));
+                OLOG(DEBUG) << "[request Transition] pushing channel configuration " << channelLines.back();
+            }
+            if (!channelLines.empty()) {
+                m_pluginServices->SetProperty("channel-config", channelLines);
+            }
+        }
         m_pluginServices->ChangeDeviceState("OCC", evt);
     }
     catch (fair::mq::PluginServices::DeviceControlError& e) {