v01

thirdparty/Pangolin/include/pangolin/factory/factory_registry.h

@@ -0,0 +1,114 @@
+/* This file is part of the Pangolin Project.
+ * http://github.com/stevenlovegrove/Pangolin
+ *
+ * Copyright (c) 2011-2013 Steven Lovegrove
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <memory>
+#include <vector>
+#include <algorithm>
+
+#include <pangolin/utils/uri.h>
+
+namespace pangolin
+{
+
+template<typename T>
+struct FactoryInterface
+{
+    typedef T FactoryItem;
+
+    virtual ~FactoryInterface() = default;
+    virtual std::unique_ptr<T> Open(const Uri& uri) = 0;
+};
+
+template<typename T>
+class FactoryRegistry
+{
+public:
+    // IMPORTANT: Implement for each templated instantiation within a seperate compilation unit.
+    static FactoryRegistry<T>& I();
+
+    ~FactoryRegistry()
+    {
+    }
+
+    void RegisterFactory(std::shared_ptr<FactoryInterface<T>> factory, uint32_t precedence, const std::string& scheme_name )
+    {
+        FactoryItem item = {precedence, scheme_name, factory};
+        factories.push_back( item );
+        std::sort(factories.begin(), factories.end());
+    }
+
+    void UnregisterFactory(FactoryInterface<T>* factory)
+    {
+        for( auto i = factories.end()-1; i != factories.begin(); --i)
+        {
+            if( i->factory.get() == factory ) {
+                factories.erase(i);
+            }
+        }
+    }
+
+    void UnregisterAllFactories()
+    {
+        factories.clear();
+    }
+
+    std::unique_ptr<T> Open(const Uri& uri)
+    {
+        // Iterate over all registered factories in order of precedence.
+        for(auto& item : factories) {
+            if( item.scheme == uri.scheme) {
+                std::unique_ptr<T> video = item.factory->Open(uri);
+                if(video) {
+                    return video;
+                }
+            }
+        }
+
+        return std::unique_ptr<T>();
+    }
+
+private:
+    struct FactoryItem
+    {
+        uint32_t precedence;
+        std::string scheme;
+        std::shared_ptr<FactoryInterface<T>> factory;
+
+        bool operator<(const FactoryItem& rhs) const {
+            return precedence < rhs.precedence;
+        }
+    };
+
+    // Priority, Factory tuple
+    std::vector<FactoryItem> factories;
+};
+
+#define PANGOLIN_REGISTER_FACTORY(x) void Register ## x ## Factory()
+
+}