From 66f2995a71e9490418872926dedc58727de0851c Mon Sep 17 00:00:00 2001
From: Matej Sekoranja <unknown>
Date: Wed, 15 Oct 2014 14:13:55 +0200
Subject: [PATCH] pvlist for servers w/ multiple providers

---
 src/server/responseHandlers.cpp | 56 +++++++++++++++++++++++----------
 src/server/serverContext.cpp    |  2 +-
 src/server/serverContext.h      |  2 +-
 3 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/src/server/responseHandlers.cpp b/src/server/responseHandlers.cpp
index 86dd22b..ec7a892 100644
--- a/src/server/responseHandlers.cpp
+++ b/src/server/responseHandlers.cpp
@@ -451,6 +451,10 @@ public:
         return _waitEvent.wait(timeoutSec);
     }
 
+    void resetEvent() {
+        _waitEvent.tryWait();
+    }
+
 private:
     epics::pvData::Mutex _waitMutex;
     epics::pvData::Event _waitEvent;
@@ -504,24 +508,44 @@ public:
         string op = opField->get();
         if (op == "channels")
         {
-            ChannelListRequesterImpl::shared_pointer listListener(new ChannelListRequesterImpl());
-            m_serverContext->getChannelProviders()[0]->channelList(listListener);               // TODO multiple channel providers !!!!
-            if (!listListener->waitForCompletion(TIMEOUT_SEC))
-                throw RPCRequestException(Status::STATUSTYPE_ERROR, "failed to fetch channel list due to timeout");
-
-            Status& status = listListener->status;
-            if (!status.isSuccess())
-            {
-                string errorMessage = "failed to fetch channel list: " + status.getMessage();
-                if (!status.getStackDump().empty())
-                     errorMessage += "\n" + status.getStackDump();
-                throw RPCRequestException(Status::STATUSTYPE_ERROR, errorMessage);
-            }
-
             PVStructure::shared_pointer result =
                 getPVDataCreate()->createPVStructure(channelListStructure);
-            PVStringArray::shared_pointer pvArray = result->getSubField<PVStringArray>("value");
-            pvArray->replace(listListener->channelNames);
+            PVStringArray::shared_pointer allChannelNames = result->getSubField<PVStringArray>("value");
+
+            ChannelListRequesterImpl::shared_pointer listListener(new ChannelListRequesterImpl());
+            std::vector<ChannelProvider::shared_pointer> providers = m_serverContext->getChannelProviders();
+
+            size_t providerCount = providers.size();
+            for (size_t i = 0; i < providerCount; i++)
+            {
+                providers[i]->channelList(listListener);
+                if (!listListener->waitForCompletion(TIMEOUT_SEC))
+                    throw RPCRequestException(Status::STATUSTYPE_ERROR, "failed to fetch channel list due to timeout");
+
+                Status& status = listListener->status;
+                if (!status.isSuccess())
+                {
+                    string errorMessage = "failed to fetch channel list: " + status.getMessage();
+                    if (!status.getStackDump().empty())
+                         errorMessage += "\n" + status.getStackDump();
+                    throw RPCRequestException(Status::STATUSTYPE_ERROR, errorMessage);
+                }
+
+                // optimization
+                if (providerCount == 1)
+                {
+                    allChannelNames->replace(listListener->channelNames);
+                }
+                else
+                {
+                    PVStringArray::svector list(allChannelNames->reuse());
+                    std::copy(listListener->channelNames.begin(), listListener->channelNames.end(),
+                              back_inserter(list));
+                    allChannelNames->replace(freeze(list));
+                }
+
+                listListener->resetEvent();
+            }
 
             return result;
         }
diff --git a/src/server/serverContext.cpp b/src/server/serverContext.cpp
index fc3b453..460bcae 100644
--- a/src/server/serverContext.cpp
+++ b/src/server/serverContext.cpp
@@ -645,7 +645,7 @@ void ServerContextImpl::setChannelProviderName(std::string channelProviderName)
     _channelProviderNames = channelProviderName;
 }
 
-std::vector<ChannelProvider::shared_pointer> ServerContextImpl::getChannelProviders()
+std::vector<ChannelProvider::shared_pointer>& ServerContextImpl::getChannelProviders()
 {
 	return _channelProviders;
 }
diff --git a/src/server/serverContext.h b/src/server/serverContext.h
index 7336bdb..61fb5e2 100644
--- a/src/server/serverContext.h
+++ b/src/server/serverContext.h
@@ -291,7 +291,7 @@ public:
 	 * Get channel providers.
 	 * @return channel providers.
 	 */
-	std::vector<ChannelProvider::shared_pointer> getChannelProviders();
+    std::vector<ChannelProvider::shared_pointer>& getChannelProviders();
 
     /**
      * Return <code>true</code> if channel provider name is provided by configuration (e.g. system env. var.).