From 8729d6a2d652403de9226dc67978eda8a7a2722b Mon Sep 17 00:00:00 2001
From: Pavel Kirienko <pavel.kirienko@gmail.com>
Date: Sun, 24 May 2015 15:59:32 +0300
Subject: [PATCH] ServiceClient<>::getCallIDByIndex()

---
 libuavcan/include/uavcan/node/service_client.hpp | 13 +++++++++++++
 libuavcan/test/node/service_client.cpp           |  6 ++++++
 2 files changed, 19 insertions(+)

diff --git a/libuavcan/include/uavcan/node/service_client.hpp b/libuavcan/include/uavcan/node/service_client.hpp
index b5a84715fa..b8467c4694 100644
--- a/libuavcan/include/uavcan/node/service_client.hpp
+++ b/libuavcan/include/uavcan/node/service_client.hpp
@@ -341,6 +341,12 @@ public:
      */
     bool hasPendingCallToServer(NodeID server_node_id) const;
 
+    /**
+     * This method allows to traverse pending calls. If the index is out of range, an invalid call ID will be returned.
+     * Warning: average complexity is O(index); worst case complexity is O(size).
+     */
+    ServiceCallID getCallIDByIndex(unsigned index) const;
+
     /**
      * Service response callback must be set prior service call.
      */
@@ -556,6 +562,13 @@ bool ServiceClient<DataType_, Callback_, NumStaticCalls_>::hasPendingCallToServe
     return NULL != call_registry_.find(ServerSearchPredicate(server_node_id));
 }
 
+template <typename DataType_, typename Callback_, unsigned NumStaticCalls_>
+ServiceCallID ServiceClient<DataType_, Callback_, NumStaticCalls_>::getCallIDByIndex(unsigned index) const
+{
+    const CallState* const id = call_registry_.getByIndex(index);
+    return (id == NULL) ? ServiceCallID() : id->getCallID();
+}
+
 }
 
 #endif // UAVCAN_NODE_SERVICE_CLIENT_HPP_INCLUDED
diff --git a/libuavcan/test/node/service_client.cpp b/libuavcan/test/node/service_client.cpp
index 8b24848a30..82d99a66ac 100644
--- a/libuavcan/test/node/service_client.cpp
+++ b/libuavcan/test/node/service_client.cpp
@@ -147,6 +147,9 @@ TEST(ServiceClient, Basic)
         ASSERT_EQ(1, client2.getNumPendingCalls());
         ASSERT_EQ(2, client3.getNumPendingCalls());
 
+        ASSERT_EQ(uavcan::NodeID(1), client2.getCallIDByIndex(0).server_node_id);
+        ASSERT_EQ(uavcan::NodeID(), client2.getCallIDByIndex(1).server_node_id);
+
         nodes.spinBoth(uavcan::MonotonicDuration::fromMSec(20));
 
         std::cout << "!!! Spin finished!" << std::endl;
@@ -216,6 +219,9 @@ TEST(ServiceClient, Rejection)
 
     ASSERT_LT(0, client1.call(1, request));
 
+    ASSERT_EQ(uavcan::NodeID(1), client1.getCallIDByIndex(0).server_node_id);
+    ASSERT_EQ(uavcan::NodeID(), client1.getCallIDByIndex(1).server_node_id);
+
     ASSERT_EQ(1, nodes.b.getDispatcher().getNumServiceResponseListeners());
     ASSERT_TRUE(client1.hasPendingCalls());
     ASSERT_TRUE(client1.hasPendingCallToServer(1));