patch_mapnik_071_use_direct_dll_interface_windows.diff

Index: include/mapnik/datasource_cache.hpp
===================================================================
--- include/mapnik/datasource_cache.hpp	(revision 2515)
+++ include/mapnik/datasource_cache.hpp	(working copy)
@@ -47,7 +47,7 @@
         datasource_cache& operator=(const datasource_cache&);
         static std::map<std::string,boost::shared_ptr<PluginInfo> > plugins_;
         static bool registered_;
-        static bool insert(const std::string&  name,const lt_dlhandle module);
+		static bool insert(const std::string& name, const TDynamicLibraryHandle module);
     public:
         static std::vector<std::string> plugin_names ();
         static void register_datasources(const std::string& path);
Index: include/mapnik/plugin.hpp
===================================================================
--- include/mapnik/plugin.hpp	(revision 2515)
+++ include/mapnik/plugin.hpp	(working copy)
@@ -28,8 +28,23 @@
 #include <boost/utility.hpp>
 // stl
 #include <string>
-// ltdl
+
+#ifdef _WIN32
+#include <windows.h>
+#include <tchar.h>
+typedef HINSTANCE TDynamicLibraryHandle;
+#define lt_dlopen ::LoadLibrary
+#define lt_dlclose ::FreeLibrary
+#define lt_dlsym ::GetProcAddress
+#define lt_dlerror() GetWinError()
+#define lt_dlexit() (void)0
+#define lt_dlinit() (void)0
+std::string GetWinError();
+#else
+// On all other platforms, use ltdl
 #include <ltdl.h>
+typedef lt_dlhandle TDynamicLibraryHandle;
+#endif
 
 namespace mapnik
 {
@@ -37,12 +52,12 @@
    {         
     private:
          std::string name_;
-         lt_dlhandle module_;     
+         TDynamicLibraryHandle module_;     
     public:
-         PluginInfo (const std::string& name,const lt_dlhandle module);
+         PluginInfo (const std::string& name,const TDynamicLibraryHandle module);
          ~PluginInfo();
          const std::string& name() const;
-         lt_dlhandle handle() const;
+         TDynamicLibraryHandle handle() const;
    };
 }
 
Index: src/datasource_cache.cpp
===================================================================
--- src/datasource_cache.cpp	(revision 2515)
+++ src/datasource_cache.cpp	(working copy)
@@ -32,7 +32,7 @@
 #include <boost/algorithm/string.hpp>
 
 // ltdl
-#include <ltdl.h>
+#include <mapnik/plugin.hpp>
 
 // stl
 #include <algorithm>
@@ -108,7 +108,7 @@
        return ds;
    }
 
-   bool datasource_cache::insert(const std::string& type,const lt_dlhandle module)
+   bool datasource_cache::insert(const std::string& type, const TDynamicLibraryHandle module)
    {
       return plugins_.insert(make_pair(type,boost::shared_ptr<PluginInfo>
                                        (new PluginInfo(type,module)))).second;     
@@ -149,7 +149,7 @@
             {
                try 
                {
-                  lt_dlhandle module=lt_dlopen(itr->string().c_str());
+                  TDynamicLibraryHandle module=lt_dlopen(itr->string().c_str());
                   if (module)
                   {
                      datasource_name* ds_name = 
Index: src/plugin.cpp
===================================================================
--- src/plugin.cpp	(revision 2515)
+++ src/plugin.cpp	(working copy)
@@ -23,12 +23,11 @@
 //$Id: plugin.cpp 17 2005-03-08 23:58:43Z pavlenko $
 
 #include <mapnik/plugin.hpp>
-#include <ltdl.h>
 
 namespace mapnik
 {
 
-    PluginInfo::PluginInfo (const std::string& name,const lt_dlhandle module)
+    PluginInfo::PluginInfo (const std::string& name, const TDynamicLibraryHandle module)
         :name_(name),module_(module) {}
 
     PluginInfo::~PluginInfo()
@@ -44,9 +43,35 @@
         return name_;
     }
 
-    lt_dlhandle PluginInfo::handle() const
+    TDynamicLibraryHandle PluginInfo::handle() const
     {
         return module_;
     }
 
 }
+
+#ifdef _WIN32
+/*
+ * This function assumes a Multi-Byte Character Set build environment.
+ * For a unicode build, some additional wcstombs() may be necessary.
+ */
+std::string GetWinError()
+{
+	LPTSTR s;
+	if(!::FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+		NULL, ::GetLastError(), 0, (LPTSTR)&s, 0, NULL))
+	{
+		/* Unknown error code. */
+		return "Unknown error.";
+	} else {
+		/* FormatMessage adds a newline for no good reason, strip it out. */
+		LPTSTR p = _tcschr(s, _T('\r'));
+		if(p != NULL) {
+			*p = _T('\0');
+		}
+		std::string result(s);
+		::LocalFree(s);
+		return result;
+	}
+}
+#endif // _WIN32
\ No newline at end of file