Adopt FairMQMessage backed memory resource collection from AliceO2

Add a pmr interface to FairMQTransportFactory

refactor

Port the unit tests for MemoryResources

clang format

fairmq/MemoryResourceTools.h

@@ -0,0 +1,119 @@
+/********************************************************************************
+ *    Copyright (C) 2018 CERN and copyright holders of ALICE O2 *
+ *    Copyright (C) 2018 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH *
+ *                                                                              *
+ *              This software is distributed under the terms of the *
+ *              GNU Lesser General Public Licence (LGPL) version 3, *
+ *                  copied verbatim in the file "LICENSE" *
+ ********************************************************************************/
+
+/// @brief Tools for interfacing containers to the transport via polymorphic
+/// allocators
+///
+/// @author Mikolaj Krzewicki, mkrzewic@cern.ch
+
+#include <fairmq/FairMQTransportFactory.h>
+#include <fairmq/MemoryResources.h>
+
+namespace fair {
+namespace mq {
+
+using ByteSpectatorAllocator = SpectatorAllocator<fair::mq::byte>;
+using BytePmrAllocator = boost::container::pmr::polymorphic_allocator<fair::mq::byte>;
+
+//_________________________________________________________________________________________________
+// return the message associated with the container or nullptr if it does not
+// make sense (e.g. when
+// we are just watching an existing message or when the container is not using
+// FairMQMemoryResource
+// as backend).
+template<typename ContainerT>
+// typename std::enable_if<
+//    std::is_base_of<
+//        boost::container::pmr::polymorphic_allocator<typename
+//        ContainerT::value_type>,
+//        typename ContainerT::allocator_type>::value == true,
+//    FairMQMessagePtr>::type
+FairMQMessagePtr getMessage(ContainerT &&container_, FairMQMemoryResource *targetResource = nullptr)
+{
+    auto container = std::move(container_);
+    auto alloc = container.get_allocator();
+
+    auto resource = dynamic_cast<FairMQMemoryResource *>(alloc.resource());
+    if (!resource && !targetResource) {
+        throw std::runtime_error("Neither the container or target resource specified");
+    }
+    size_t containerSizeBytes = container.size() * sizeof(typename ContainerT::value_type);
+    if ((!targetResource && resource)
+        || (resource && targetResource && resource->is_equal(*targetResource))) {
+        auto message = resource->getMessage(static_cast<void *>(
+            const_cast<typename std::remove_const<typename ContainerT::value_type>::type *>(
+                container.data())));
+        if (message)
+            message->SetUsedSize(containerSizeBytes);
+        return std::move(message);
+    } else {
+        auto message = targetResource->getTransportFactory()->CreateMessage(containerSizeBytes);
+        std::memcpy(static_cast<fair::mq::byte *>(message->GetData()),
+                    container.data(),
+                    containerSizeBytes);
+        return std::move(message);
+    }
+};
+
+//_________________________________________________________________________________________________
+/// Return a vector of const ElemT, resource must be kept alive throughout the
+/// lifetime of the
+/// container and associated message.
+template<typename ElemT>
+std::vector<const ElemT, boost::container::pmr::polymorphic_allocator<const ElemT>> adoptVector(
+    size_t nelem,
+    SpectatorMessageResource *resource)
+{
+    return std::vector<const ElemT, SpectatorAllocator<const ElemT>>(
+        nelem, SpectatorAllocator<ElemT>(resource));
+};
+
+//_________________________________________________________________________________________________
+/// Return a vector of const ElemT, takes ownership of the message, needs an
+/// upstream global
+/// ChannelResource to register the message.
+template<typename ElemT>
+std::vector<const ElemT, OwningMessageSpectatorAllocator<const ElemT>>
+    adoptVector(size_t nelem, ChannelResource *upstream, FairMQMessagePtr message)
+{
+    return std::vector<const ElemT, OwningMessageSpectatorAllocator<const ElemT>>(
+        nelem,
+        OwningMessageSpectatorAllocator<const ElemT>(
+            MessageResource{std::move(message), upstream}));
+};
+
+//_________________________________________________________________________________________________
+// TODO: this is C++14, converting it down to C++11 is too much work atm
+// This returns a unique_ptr of const vector, does not allow modifications at
+// the cost of pointer
+// semantics for access.
+// use auto or decltype to catch the return value (or use span)
+// template<typename ElemT>
+// auto adoptVector(size_t nelem, FairMQMessage* message)
+//{
+//    using DataType = std::vector<ElemT, ByteSpectatorAllocator>;
+//
+//    struct doubleDeleter
+//    {
+//        // kids: don't do this at home! (but here it's OK)
+//        // this stateful deleter allows a single unique_ptr to manage 2
+//        resources at the same time.
+//        std::unique_ptr<SpectatorMessageResource> extra;
+//        void operator()(const DataType* ptr) { delete ptr; }
+//    };
+//
+//    using OutputType = std::unique_ptr<const DataType, doubleDeleter>;
+//
+//    auto resource = std::make_unique<SpectatorMessageResource>(message);
+//    auto output = new DataType(nelem, ByteSpectatorAllocator{resource.get()});
+//    return OutputType(output, doubleDeleter{std::move(resource)});
+//}
+
+} /* namespace mq */
+} /* namespace fair */