From 8866afe8ee318701eb4e12a389d066e11a6d189c Mon Sep 17 00:00:00 2001
From: Howard Butler <hobu.inc@gmail.com>
Date: Fri, 5 Jul 2013 11:43:22 -0500
Subject: [PATCH] provide implementation for plugin versioning #154

---
 include/pdal/Utils.hpp       |  5 ++++-
 include/pdal/pdal_config.hpp |  1 +
 include/pdal/pdal_error.hpp  |  9 +++++++++
 include/pdal/pdal_macros.hpp |  9 +++++++++
 pdal_defines.h.in            |  2 ++
 src/StageFactory.cpp         | 11 ++++++++---
 src/Utils.cpp                | 24 +++++++++++++++++++++---
 7 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/include/pdal/Utils.hpp b/include/pdal/Utils.hpp
index a25345c547..41308065f1 100644
--- a/include/pdal/Utils.hpp
+++ b/include/pdal/Utils.hpp
@@ -193,7 +193,10 @@ class PDAL_DLL Utils
 
     }
     
-    static void registerPlugin(void* stageFactoryPtr, std::string const& filename, std::string const& method);
+    static void* registerPlugin( void* stageFactoryPtr, 
+                                std::string const& filename, 
+                                std::string const& registerMethodName,
+                                std::string const& versionMethodName);
 
     static char* getenv(const char* env);
     static std::string getenv(std::string const& name);
diff --git a/include/pdal/pdal_config.hpp b/include/pdal/pdal_config.hpp
index a2ced7eb2b..2311e0844f 100644
--- a/include/pdal/pdal_config.hpp
+++ b/include/pdal/pdal_config.hpp
@@ -66,6 +66,7 @@ PDAL_DLL int GetVersionPatch();
 
 
 
+
 } // namespace pdal
 
 #endif
diff --git a/include/pdal/pdal_error.hpp b/include/pdal/pdal_error.hpp
index 6ec89375db..f83db7d2f4 100644
--- a/include/pdal/pdal_error.hpp
+++ b/include/pdal/pdal_error.hpp
@@ -299,6 +299,15 @@ class python_error : public std::runtime_error
     {}
 };
 
+class plugin_error : public std::runtime_error
+{
+public:
+    plugin_error(std::string const& msg)
+        : std::runtime_error(msg)
+    {}
+};
+
+
 } // namespace pdal
 
 #endif // PDAL_EXCEPTION_HPP_INCLUDED
diff --git a/include/pdal/pdal_macros.hpp b/include/pdal/pdal_macros.hpp
index 1e769f16d7..347f891fc2 100644
--- a/include/pdal/pdal_macros.hpp
+++ b/include/pdal/pdal_macros.hpp
@@ -107,4 +107,13 @@
     } \
     PDAL_C_END 
 
+#define SET_PLUGIN_VERSION(DriverName) \
+    PDAL_C_START PDAL_DLL int PDALRegister_version_##DriverName() \
+    { \
+        return PDAL_PLUGIN_VERSION; \
+    } \
+    PDAL_C_END 
+
+
 #endif
+
diff --git a/pdal_defines.h.in b/pdal_defines.h.in
index b5fab3baf7..2f43b275a5 100644
--- a/pdal_defines.h.in
+++ b/pdal_defines.h.in
@@ -17,6 +17,8 @@
 
 #define PDAL_VERSION_STRING "@PDAL_VERSION_STRING@"
 
+#define PDAL_PLUGIN_VERSION 1
+
 /* (note this will look yucky until we get to major>=1) */
 #define PDAL_VERSION_INTEGER ((PDAL_VERSION_MAJOR*100*100)+(PDAL_VERSION_MINOR*100)+PDAL_VERSION_PATCH)
 
diff --git a/src/StageFactory.cpp b/src/StageFactory.cpp
index 3639ff25a9..517eb8c037 100644
--- a/src/StageFactory.cpp
+++ b/src/StageFactory.cpp
@@ -527,7 +527,6 @@ void StageFactory::loadPlugins()
 {
     using namespace boost::filesystem;
 
-    typedef boost::tokenizer<boost::char_separator<char> > tokenizer;
 
     std::string driver_path("PDAL_DRIVER_PATH");
     std::string pluginDir = Utils::getenv(driver_path);
@@ -636,8 +635,14 @@ void StageFactory::registerPlugin(std::string const& filename)
         }
     }    
     
-    std::string methodName = "PDALRegister_" + boost::algorithm::ireplace_first_copy(basename.string(), "libpdal_plugin_", "");
-    Utils::registerPlugin((void*)this, filename, methodName);
+    std::string base = basename.string();
+
+    std::string registerMethodName = "PDALRegister_" + \
+            boost::algorithm::ireplace_first_copy(base, "libpdal_plugin_", "");
+
+    std::string versionMethodName = "PDALRegister_version_" +  base.substr( base.find_last_of("_")+1, base.size());
+
+    Utils::registerPlugin((void*)this, filename, registerMethodName, versionMethodName);
     
 }
 
diff --git a/src/Utils.cpp b/src/Utils.cpp
index 7dd59d6507..e02d379221 100644
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -75,20 +75,38 @@ double Utils::random(double minimum, double maximum)
     return t;
 }
 
-void Utils::registerPlugin(void* stageFactoryPtr, std::string const& filename, std::string const& method)
+void* Utils::registerPlugin( void* stageFactoryPtr, 
+                            std::string const& filename, 
+                            std::string const& registerMethod,
+                            std::string const& versionMethod)
 {
     void* pRegister;
+    void* pVersion;
 
-    pRegister = Utils::getDLLSymbol(filename, method);
+    pVersion = Utils::getDLLSymbol(filename, versionMethod);
+    
+    int plugins_version =   ((int (*)()) pVersion)();
+    
+    if (plugins_version != PDAL_PLUGIN_VERSION)
+    {
+        std::ostringstream oss;
+        oss << "Unable to register shared library '" << filename << "' with method name '" << registerMethod << "' version of plugin, '" << plugins_version << "' did not match PDALs version '" << PDAL_PLUGIN_VERSION << "'";
+        throw pdal_error(oss.str());
+    }
+
+    
+    pRegister = Utils::getDLLSymbol(filename, registerMethod);
     if (pRegister != NULL)
     {
         ((void (*)(void*)) pRegister)(stageFactoryPtr);
     } else
     {
         std::ostringstream oss;
-        oss << "Unable to register shared library '" << filename << "' with method name '" << method << "'";
+        oss << "Unable to register shared library '" << filename << "' with method name '" << registerMethod << "'";
         throw pdal_error(oss.str());
     }
+    
+    return pRegister;
 }