[1976] Hold a cache in the DataSourceInfo

It is not created now, but there's the place to put it.

src/lib/datasrc/client_list.cc

@@ -15,6 +15,7 @@
 #include "client_list.h"
 #include "client.h"
 #include "factory.h"
+#include "memory_datasrc.h"
 
 #include <memory>
 #include <boost/foreach.hpp>
@@ -25,6 +26,17 @@ using namespace std;
 namespace isc {
 namespace datasrc {
 
+ConfigurableClientList::DataSourceInfo::DataSourceInfo(
+    DataSourceClient* data_src_client,
+    const DataSourceClientContainerPtr& container, bool hasCache) :
+    data_src_client_(data_src_client),
+    container_(container)
+{
+    if (hasCache) {
+        cache_.reset(new InMemoryClient);
+    }
+}
+
 void
 ConfigurableClientList::configure(const Element& config, bool) {
     // TODO: Implement the cache
@@ -50,7 +62,8 @@ ConfigurableClientList::configure(const Element& config, bool) {
             const DataSourcePair ds(this->getDataSourceClient(type,
                                                               paramConf));
             // And put it into the vector
-            new_data_sources.push_back(DataSourceInfo(ds.first, ds.second));
+            new_data_sources.push_back(DataSourceInfo(ds.first, ds.second,
+                                                      false));
         }
         // If everything is OK up until now, we have the new configuration
         // ready. So just put it there and let the old one die when we exit

src/lib/datasrc/client_list.h

@@ -33,6 +33,7 @@ typedef boost::shared_ptr<DataSourceClient> DataSourceClientPtr;
 class DataSourceClientContainer;
 typedef boost::shared_ptr<DataSourceClientContainer>
     DataSourceClientContainerPtr;
+class InMemoryClient;
 
 /// \brief The list of data source clients.
 ///
@@ -231,12 +232,11 @@ public:
             data_src_client_(NULL)
         {}
         DataSourceInfo(DataSourceClient* data_src_client,
-                       const DataSourceClientContainerPtr& container) :
-            data_src_client_(data_src_client),
-            container_(container)
-        {}
+                       const DataSourceClientContainerPtr& container,
+                       bool hasCache);
         DataSourceClient* data_src_client_;
         DataSourceClientContainerPtr container_;
+        boost::shared_ptr<InMemoryClient> cache_;
     };
 
     /// \brief The collection of data sources.

src/lib/datasrc/tests/client_list_unittest.cc

@@ -175,7 +175,7 @@ public:
                 ds(new MockDataSourceClient(ds_zones[i]));
             ds_.push_back(ds);
             ds_info_.push_back(ConfigurableClientList::DataSourceInfo(ds.get(),
-                DataSourceClientContainerPtr()));
+                DataSourceClientContainerPtr(), false));
         }
     }
     // Check the positive result is as we expect it.
@@ -220,7 +220,8 @@ public:
                 FAIL() << "Unknown configuration index " << index;
         }
     }
-    void checkDS(size_t index, const string& type, const string& params) const
+    void checkDS(size_t index, const string& type, const string& params,
+                 bool cache) const
     {
         ASSERT_GT(list_->getDataSources().size(), index);
         MockDataSourceClient* ds(dynamic_cast<MockDataSourceClient*>(
@@ -230,6 +231,8 @@ public:
         ASSERT_NE(ds, static_cast<const MockDataSourceClient*>(NULL));
         EXPECT_EQ(type, ds->type_);
         EXPECT_TRUE(Element::fromJSON(params)->equals(*ds->configuration_));
+        EXPECT_EQ(cache, list_->getDataSources()[index].cache_ !=
+                  shared_ptr<InMemoryClient>());
     }
     shared_ptr<TestedList> list_;
     const ClientList::FindResult negativeResult_;
@@ -370,8 +373,8 @@ TEST_F(ListTest, configureMulti) {
     ));
     list_->configure(*elem, true);
     EXPECT_EQ(2, list_->getDataSources().size());
-    checkDS(0, "type1", "{}");
-    checkDS(1, "type2", "{}");
+    checkDS(0, "type1", "{}", false);
+    checkDS(1, "type2", "{}", false);
 }
 
 // Check we can pass whatever we want to the params
@@ -396,7 +399,7 @@ TEST_F(ListTest, configureParams) {
             "}]"));
         list_->configure(*elem, true);
         EXPECT_EQ(1, list_->getDataSources().size());
-        checkDS(0, "t", *param);
+        checkDS(0, "t", *param, false);
     }
 }
 
@@ -423,14 +426,14 @@ TEST_F(ListTest, wrongConfig) {
     };
     // Put something inside to see it survives the exception
     list_->configure(*config_elem_, true);
-    checkDS(0, "test_type", "{}");
+    checkDS(0, "test_type", "{}", false);
     for (const char** config(configs); *config; ++config) {
         SCOPED_TRACE(*config);
         ConstElementPtr elem(Element::fromJSON(*config));
         EXPECT_THROW(list_->configure(*elem, true),
                      ConfigurableClientList::ConfigurationError);
         // Still untouched
-        checkDS(0, "test_type", "{}");
+        checkDS(0, "test_type", "{}", false);
         EXPECT_EQ(1, list_->getDataSources().size());
     }
 }
@@ -443,18 +446,18 @@ TEST_F(ListTest, defaults) {
         "}]"));
     list_->configure(*elem, true);
     EXPECT_EQ(1, list_->getDataSources().size());
-    checkDS(0, "type1", "null");
+    checkDS(0, "type1", "null", false);
 }
 
 // Check we can call the configure multiple times, to change the configuration
 TEST_F(ListTest, reconfigure) {
     ConstElementPtr empty(new ListElement);
     list_->configure(*config_elem_, true);
-    checkDS(0, "test_type", "{}");
+    checkDS(0, "test_type", "{}", false);
     list_->configure(*empty, true);
     EXPECT_TRUE(list_->getDataSources().empty());
     list_->configure(*config_elem_, true);
-    checkDS(0, "test_type", "{}");
+    checkDS(0, "test_type", "{}", false);
 }
 
 // Make sure the data source error exception from the factory is propagated
@@ -464,9 +467,9 @@ TEST_F(ListTest, dataSrcError) {
         "   \"type\": \"error\""
         "}]"));
     list_->configure(*config_elem_, true);
-    checkDS(0, "test_type", "{}");
+    checkDS(0, "test_type", "{}", false);
     EXPECT_THROW(list_->configure(*elem, true), DataSourceError);
-    checkDS(0, "test_type", "{}");
+    checkDS(0, "test_type", "{}", false);
 }
 
 }