From 6f9528c2e3c6e81b53983671d5f1e562286c1ab2 Mon Sep 17 00:00:00 2001
From: Artem Pavlenko <artem@mapnik.org>
Date: Wed, 14 Dec 2005 17:01:09 +0000
Subject: [PATCH] 1.added serialization support 2.some class names changes

---
 SConstruct                               |  8 +--
 boost/SConscript                         | 11 +++-
 datasources/postgis/postgis.cpp          |  2 +-
 datasources/postgis/postgis.hpp          |  2 +-
 datasources/raster/raster_datasource.cpp |  2 +-
 datasources/raster/raster_datasource.hpp |  2 +-
 datasources/shape/shape.cpp              |  2 +-
 datasources/shape/shape.hpp              |  2 +-
 include/datasource.hpp                   |  4 +-
 include/datasource_cache.hpp             |  2 +-
 include/layer.hpp                        | 35 +++++++++--
 include/map.hpp                          | 22 ++++++-
 include/mapnik.hpp                       |  5 ++
 include/params.hpp                       | 77 +++++++++++++++++++-----
 python/mapnik_layer.cpp                  |  6 +-
 python/mapnik_parameters.cpp             | 29 +++++----
 src/SConscript                           |  3 +-
 src/datasource_cache.cpp                 |  4 +-
 src/layer.cpp                            | 51 +++++++++-------
 src/map.cpp                              | 11 ++--
 src/mapnik.cpp                           | 61 +++++++++++++++++++
 src/params.cpp                           | 35 +----------
 src/scanline_aa.cpp                      |  4 +-
 23 files changed, 260 insertions(+), 120 deletions(-)
 create mode 100644 src/mapnik.cpp

diff --git a/SConstruct b/SConstruct
index 991b5ca41..d62d28bf0 100644
--- a/SConstruct
+++ b/SConstruct
@@ -41,11 +41,11 @@ build_prefix = build_dir+'/'+str(platform)
 
 env = Environment(ENV=os.environ, options=opts)
 
-cxx_debug='-Wall -ftemplate-depth-100 -O0 -fno-inline -g -pthread -DDEBUG'
-cxx_release='-Wall -ftemplate-depth-100 -O3 -finline-functions -Wno-inline -pthread -DNDEBUG'
+cxx_debug='-Wall -Wno-non-virtual-dtor -Wno-ctor-dtor-privacy -ftemplate-depth-100 -O0 -fno-inline -g -pthread -DDEBUG'
+cxx_release='-Wall -Wno-non-virtual-dtor -Wno-ctor-dtor-privacy -ftemplate-depth-100 -O3 -finline-functions -Wno-inline -pthread -DNDEBUG '
 
-release_env = env.Copy(CXXFLAGS = cxx_release)
-debug_env = env.Copy(CXXFLAGS = cxx_debug)
+#release_env = env.Copy(CXXFLAGS = cxx_release)
+#debug_env = env.Copy(CXXFLAGS = cxx_debug)
 
 if ARGUMENTS.get('debug',0):
     env.Append(CXXFLAGS = cxx_debug)
diff --git a/boost/SConscript b/boost/SConscript
index b015e7c2d..17c8b30d8 100644
--- a/boost/SConscript
+++ b/boost/SConscript
@@ -24,16 +24,23 @@ Import('env')
 prefix = env['PREFIX']
 boost_root = env['BOOST_ROOT']
 
-# boost filesystem
+#boost filesystem
 filesystem_src_dir = boost_root + '/libs/filesystem/src/'
 boost_fs_src= glob.glob(filesystem_src_dir + '*.cpp')
 lib_boost_filesystem = env.SharedLibrary('libboost-filesystem',boost_fs_src,LIBS=[],CPPPATH=boost_root)
 env.Install(prefix+'/lib',lib_boost_filesystem)
+
 #boost regex
 regex_src_dir = boost_root + '/libs/regex/src/'
 boost_regex_src = glob.glob(regex_src_dir+ '*.cpp')
 lib_boost_regex = env.SharedLibrary('libboost-regex',boost_regex_src,LIBS=[],CPPPATH=boost_root)
-
 env.Install(prefix+'/lib',lib_boost_regex)
 
+#boost serialization
+serialization_src_dir = boost_root + '/libs/serialization/src/'
+boost_serialization_src = glob.glob(serialization_src_dir+ '*.cpp')
+#cxxflags = env['CXXFLAGS'] + " -Wno-non-virtual-dtor -Wno-ctor-dtor-privacy"
+#lib_boost_serialization = env.SharedLibrary('libboost-serialization',boost_serialization_src,CXXFLAGS=cxxflags,LIBS=[],CPPPATH=boost_root)
+lib_boost_serialization = env.SharedLibrary('libboost-serialization',boost_serialization_src,LIBS=[],CPPPATH=boost_root)
+env.Install(prefix+'/lib',lib_boost_serialization)
 
diff --git a/datasources/postgis/postgis.cpp b/datasources/postgis/postgis.cpp
index 273f1c9b6..16f2aae4a 100644
--- a/datasources/postgis/postgis.cpp
+++ b/datasources/postgis/postgis.cpp
@@ -38,7 +38,7 @@ using boost::lexical_cast;
 using boost::bad_lexical_cast;
 using boost::shared_ptr;
 
-postgis_datasource::postgis_datasource(const Parameters& params)
+postgis_datasource::postgis_datasource(const parameters& params)
     : table_(params.get("table")),
       type_(datasource::Vector), 
       desc_(params.get("name")),
diff --git a/datasources/postgis/postgis.hpp b/datasources/postgis/postgis.hpp
index a2ad1bc60..20bd36606 100644
--- a/datasources/postgis/postgis.hpp
+++ b/datasources/postgis/postgis.hpp
@@ -54,7 +54,7 @@ public:
     featureset_ptr features(const query& q) const;
     mapnik::Envelope<double> const& envelope() const;
     layer_descriptor const& get_descriptor() const;
-    postgis_datasource(const Parameters &params);
+    postgis_datasource(const parameters &params);
     ~postgis_datasource();
 private:
     static std::string table_from_sql(const std::string& sql);
diff --git a/datasources/raster/raster_datasource.cpp b/datasources/raster/raster_datasource.cpp
index 17016f9c1..4b8fd57c9 100644
--- a/datasources/raster/raster_datasource.cpp
+++ b/datasources/raster/raster_datasource.cpp
@@ -31,7 +31,7 @@ using std::endl;
 using boost::lexical_cast;
 using boost::bad_lexical_cast;
 
-raster_datasource::raster_datasource(const Parameters& params)
+raster_datasource::raster_datasource(const parameters& params)
     : desc_(params.get("name"))
 {
     filename_=params.get("file");
diff --git a/datasources/raster/raster_datasource.hpp b/datasources/raster/raster_datasource.hpp
index 37ffa48c2..a3c381345 100644
--- a/datasources/raster/raster_datasource.hpp
+++ b/datasources/raster/raster_datasource.hpp
@@ -37,7 +37,7 @@ private:
     layer_descriptor             desc_;
     static std::string           name_;  
 public:
-    raster_datasource(const Parameters& params);
+    raster_datasource(const parameters& params);
     virtual            ~raster_datasource();
     int                 type() const;
     static std::string  name();
diff --git a/datasources/shape/shape.cpp b/datasources/shape/shape.cpp
index 258a3340a..3af2f69d4 100644
--- a/datasources/shape/shape.cpp
+++ b/datasources/shape/shape.cpp
@@ -26,7 +26,7 @@
 
 DATASOURCE_PLUGIN(shape_datasource);
 
-shape_datasource::shape_datasource(const Parameters &params)
+shape_datasource::shape_datasource(const parameters &params)
     : shape_name_(params.get("file")),
       type_(datasource::Vector),
       file_length_(0),
diff --git a/datasources/shape/shape.hpp b/datasources/shape/shape.hpp
index 1db981cb3..db57f9691 100644
--- a/datasources/shape/shape.hpp
+++ b/datasources/shape/shape.hpp
@@ -33,7 +33,7 @@ public:
     static std::string name();
     featureset_ptr features(const query& q) const;
     const Envelope<double>& envelope() const;
-    shape_datasource(const Parameters &params);
+    shape_datasource(const parameters &params);
     layer_descriptor const& get_descriptor() const;
     virtual ~shape_datasource();
 private:
diff --git a/include/datasource.hpp b/include/datasource.hpp
index 172340123..a926662c9 100644
--- a/include/datasource.hpp
+++ b/include/datasource.hpp
@@ -72,7 +72,7 @@ namespace mapnik
     };
     
     typedef std::string datasource_name();
-    typedef datasource* create_ds(const Parameters& params);
+    typedef datasource* create_ds(const parameters& params);
     typedef void destroy_ds(datasource *ds);
 
     
@@ -93,7 +93,7 @@ namespace mapnik
         { \
         return classname::name();\
         }\
-        extern "C"  datasource* create(const Parameters &params) \
+        extern "C"  datasource* create(const parameters &params)	\
         { \
 	    return new classname(params);	\
         }\
diff --git a/include/datasource_cache.hpp b/include/datasource_cache.hpp
index c71744424..5446fd6af 100644
--- a/include/datasource_cache.hpp
+++ b/include/datasource_cache.hpp
@@ -43,7 +43,7 @@ namespace mapnik
 	static bool insert(const std::string&  name,const lt_dlhandle module);
     public:
 	static void register_datasources(const std::string& path);
-	static boost::shared_ptr<datasource> create(Parameters const& params);
+	static boost::shared_ptr<datasource> create(parameters const& params);
     };
 }
 #endif   //DATASOURCE_CACHE_HPP
diff --git a/include/layer.hpp b/include/layer.hpp
index 88b1c110b..b46cb73f2 100644
--- a/include/layer.hpp
+++ b/include/layer.hpp
@@ -25,29 +25,45 @@
 #include "feature.hpp"
 #include "datasource.hpp"
 #include <boost/shared_ptr.hpp>
+#include <boost/serialization/serialization.hpp>
 
 namespace mapnik
 {
     class Layer
     {
-    private:
-	Parameters params_;
+	friend class boost::serialization::access;
+	template <typename Archive>
+	void serialize(Archive & ar, const unsigned int /*version*/)
+	{
+	    ar  & boost::serialization::make_nvp("name",name_)
+		& boost::serialization::make_nvp("params",params_)
+		& boost::serialization::make_nvp("min_zoom",minZoom_)
+		& boost::serialization::make_nvp("max_zoom",maxZoom_)
+		& boost::serialization::make_nvp("active",active_)
+		& boost::serialization::make_nvp("selectable",selectable_)
+		& boost::serialization::make_nvp("styles",styles_)
+		;
+	}
+	parameters params_;
 	std::string name_;
 	double minZoom_;
 	double maxZoom_;
 	bool active_;
 	bool selectable_;
-	datasource_p ds_;	
+	
 	std::vector<std::string>  styles_;
 	std::string selection_style_;
+
+	mutable datasource_p ds_;
 	mutable std::vector<boost::shared_ptr<Feature> > selection_;
-	
+        
     public:
-	explicit Layer(const Parameters& params);
+	Layer();
+	explicit Layer(const parameters& params);
 	Layer(Layer const& l);
 	Layer& operator=(Layer const& l);
 	bool operator==(Layer const& other) const;
-	Parameters const& params() const;	
+	parameters const& params() const;	
 	const std::string& name() const;
 	void add_style(std::string const& stylename);
 	std::vector<std::string> const& styles() const;
@@ -72,4 +88,11 @@ namespace mapnik
 	void swap(const Layer& other);
     };
 }
+
+BOOST_CLASS_IMPLEMENTATION(std::vector<std::string>, boost::serialization::object_serializable)
+BOOST_CLASS_TRACKING(std::vector<std::string>, boost::serialization::track_never)
+
+BOOST_CLASS_IMPLEMENTATION(mapnik::Layer, boost::serialization::object_serializable)
+BOOST_CLASS_TRACKING(mapnik::Layer, boost::serialization::track_never)
+
 #endif //LAYER_HPP
diff --git a/include/map.hpp b/include/map.hpp
index 2089d368d..6ef59e849 100644
--- a/include/map.hpp
+++ b/include/map.hpp
@@ -21,13 +21,25 @@
 #ifndef MAP_HPP
 #define MAP_HPP
 
+#include <boost/serialization/serialization.hpp>
+#include <boost/serialization/vector.hpp>
+
 namespace mapnik
 {
     class Layer;
 
     class Map
     {
-    private:
+	friend class boost::serialization::access;
+	template <typename Archive>
+	void serialize(Archive & ar, const unsigned int /*version*/)
+	{
+	    ar  & boost::serialization::make_nvp("width",width_) 
+		& boost::serialization::make_nvp("height",height_) 
+		& boost::serialization::make_nvp("srid",srid_)
+		& boost::serialization::make_nvp("layers",layers_);
+	}
+	
 	static const unsigned MIN_MAPSIZE=16;
 	static const unsigned MAX_MAPSIZE=1024;
 	unsigned width_;
@@ -37,6 +49,7 @@ namespace mapnik
 	std::vector<Layer> layers_;
 	Envelope<double> currentExtent_;
     public:
+	Map();
 	Map(int width,int height,int srid=-1);
 	Map(const Map& rhs);
 	Map& operator=(const Map& rhs);
@@ -65,4 +78,11 @@ namespace mapnik
 	void fixAspectRatio();
     };
 }
+
+BOOST_CLASS_IMPLEMENTATION(std::vector<mapnik::Layer>, boost::serialization::object_serializable)
+BOOST_CLASS_TRACKING(std::vector<mapnik::Layer>, boost::serialization::track_never)
+
+BOOST_CLASS_IMPLEMENTATION(mapnik::Map, boost::serialization::object_serializable)
+BOOST_CLASS_TRACKING(mapnik::Map, boost::serialization::track_never)
+
 #endif //MAP_HPP
diff --git a/include/mapnik.hpp b/include/mapnik.hpp
index 8ade5f884..fc3d81bc6 100644
--- a/include/mapnik.hpp
+++ b/include/mapnik.hpp
@@ -71,6 +71,11 @@
 
 namespace mapnik
 {
+    void save_to_xml(Map const& map,const char* filename);  
+    void save_to_text(Map const& map,const char* filename);
+
+    void load_from_xml(Map & map, const char * filename);
+    void load_from_text(Map & map, const char * filename);
 }
 
 #endif //MAPNIK_HPP
diff --git a/include/params.hpp b/include/params.hpp
index 484ab5c80..e879fefdf 100644
--- a/include/params.hpp
+++ b/include/params.hpp
@@ -22,26 +22,75 @@
 #define PARAMS_HPP
 
 #include <map>
+//#include <boost/serialization/serialization.hpp>
+//#include <boost/serialization/split_member.hpp>
+//#include <boost/serialization/map.hpp>
+#include <boost/serialization/serialization.hpp>
+#include <boost/serialization/nvp.hpp>
+#include <boost/serialization/utility.hpp>
+#include <boost/serialization/vector.hpp>
+#include <boost/serialization/map.hpp>
+#include <boost/serialization/string.hpp>
+#include <boost/serialization/level.hpp>
+#include <boost/serialization/tracking.hpp>
+#include <boost/serialization/base_object.hpp>
 
 namespace mapnik
 {
 
-    typedef std::pair<std::string,std::string> Parameter;
+    typedef std::pair<const std::string,std::string> parameter;
+    typedef std::map<const std::string,std::string> param_map;
 
-    class Parameters
+    class parameters : public param_map
     {
-        typedef std::map<std::string,std::string> ParamMap;
-    private:
-	ParamMap data_;
+	friend class boost::serialization::access;
+	
+	template <typename Archive>
+	void save(Archive & ar, const unsigned int /*version*/) const
+	{
+	    const size_t size = param_map::size();
+	    ar & boost::serialization::make_nvp("count",size);
+	    param_map::const_iterator itr;
+	    for (itr=param_map::begin();itr!=param_map::end();++itr)
+	    {
+		ar & boost::serialization::make_nvp("name",itr->first);
+		ar & boost::serialization::make_nvp("value",itr->second);
+	    }
+	}
+	
+	template <typename Archive>
+	void load(Archive & ar, const unsigned int /*version*/)
+	{	    
+	    size_t size;
+	    ar & boost::serialization::make_nvp("size",size);
+	    for (size_t i=0;i<size;++i)
+	    {
+		std::string name;
+		std::string value;
+		ar & boost::serialization::make_nvp("name",name);
+		ar & boost::serialization::make_nvp("value",value);
+		param_map::insert(make_pair(name,value));
+	    }
+	}
+	BOOST_SERIALIZATION_SPLIT_MEMBER()
     public:
-	typedef ParamMap::const_iterator const_iterator;
-	Parameters() {}
-	const std::string get(const std::string& name) const;
-	void add(const Parameter& param);
-	void add(const std::string& name,const std::string& value);
-	const_iterator begin() const;
-	const_iterator end() const;
-	virtual ~Parameters();
+	parameters() {}
+	const std::string get(std::string const& key) const
+	{
+	    param_map::const_iterator itr=find(key);
+	    if (itr != end())
+	    {
+		return itr->second;
+	    }
+	    return std::string();
+	}
     };
 }
-#endif                                            //PARAMS_HPP
+
+BOOST_CLASS_IMPLEMENTATION(mapnik::parameter, boost::serialization::object_serializable)
+BOOST_CLASS_TRACKING(mapnik::parameter, boost::serialization::track_never)
+
+BOOST_CLASS_IMPLEMENTATION(mapnik::parameters, boost::serialization::object_serializable)
+BOOST_CLASS_TRACKING(mapnik::parameters, boost::serialization::track_never)
+
+#endif //PARAMS_HPP
diff --git a/python/mapnik_layer.cpp b/python/mapnik_layer.cpp
index e6a451ef2..09905a744 100644
--- a/python/mapnik_layer.cpp
+++ b/python/mapnik_layer.cpp
@@ -25,7 +25,7 @@
 #include <mapnik.hpp>
 
 using mapnik::Layer;
-using mapnik::Parameters;
+using mapnik::parameters;
 
 struct layer_pickle_suite : boost::python::pickle_suite
 {
@@ -85,13 +85,13 @@ namespace
     using namespace boost::python;
     Layer create_layer(const dict& d)
     {
-	Parameters params;
+	parameters params;
 	boost::python::list keys=d.keys();
 	for (int i=0;i<len(keys);++i)
 	{
 	    std::string key=extract<std::string>(keys[i]);
             std::string value=extract<std::string>(d[key]);
-	    params.add(key,value);
+	    params[key] = value;
 	}
 	return Layer(params);
     }
diff --git a/python/mapnik_parameters.cpp b/python/mapnik_parameters.cpp
index 03422b0a0..00cc78f8e 100644
--- a/python/mapnik_parameters.cpp
+++ b/python/mapnik_parameters.cpp
@@ -22,17 +22,16 @@
 #include <boost/python/detail/api_placeholder.hpp>
 #include <mapnik.hpp>
 
-using mapnik::Parameter;
-using mapnik::Parameters;
+using mapnik::parameter;
+using mapnik::parameters;
 
-
-void (Parameters::*add1)(const Parameter&)=&Parameters::add;
-void (Parameters::*add2)(const std::string&,const std::string&)=&Parameters::add;
+//void (parameters::*add1)(const parameter&)=&parameters::insert;
+//void (parameters::*add2)(std::make_pair(const std::string&,const std::string&))=&parameters::insert;
 
 struct parameter_pickle_suite : boost::python::pickle_suite
 {
     static boost::python::tuple
-    getinitargs(const Parameter& p)
+    getinitargs(const parameter& p)
     {
         using namespace boost::python;
         return boost::python::make_tuple(p.first,p.second);
@@ -42,11 +41,11 @@ struct parameter_pickle_suite : boost::python::pickle_suite
 struct parameters_pickle_suite : boost::python::pickle_suite
 {
     static boost::python::tuple
-    getstate(const Parameters& p)
+    getstate(const parameters& p)
     {
         using namespace boost::python;
         dict d;
-        Parameters::const_iterator pos=p.begin();
+        parameters::const_iterator pos=p.begin();
         while(pos!=p.end())
         {
             d[pos->first]=pos->second;
@@ -55,7 +54,7 @@ struct parameters_pickle_suite : boost::python::pickle_suite
         return boost::python::make_tuple(d);
     }
 
-    static void setstate(Parameters& p, boost::python::tuple state)
+    static void setstate(parameters& p, boost::python::tuple state)
     {
         using namespace boost::python;
         if (len(state) != 1)
@@ -72,7 +71,7 @@ struct parameters_pickle_suite : boost::python::pickle_suite
         {
             std::string key=extract<std::string>(keys[i]);
             std::string value=extract<std::string>(d[key]);
-            p.add(key,value);
+            p[key] = value;
         }
     }
 };
@@ -81,14 +80,14 @@ struct parameters_pickle_suite : boost::python::pickle_suite
 void export_parameters()
 {
     using namespace boost::python;
-    class_<Parameter>("parameter",init<std::string,std::string>())
+    class_<parameter>("parameter",init<std::string,std::string>())
         .def_pickle(parameter_pickle_suite())
         ;
 
-    class_<Parameters>("parameters",init<>())
-        .def("add",add1)
-        .def("add",add2)
-        .def("get",&Parameters::get)
+    class_<parameters>("parameters",init<>())
+        //.def("add",add1)
+        //.def("add",add2)
+        .def("get",&parameters::get)
         .def_pickle(parameters_pickle_suite())
         ;
 }
diff --git a/src/SConscript b/src/SConscript
index 96fa49602..16acf8425 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -30,12 +30,13 @@ freetype2_root = env['FREETYPE2_ROOT']
 
 headers =[ '#include',boost_root,freetype2_root,agg_headers]
 
-libraries=['rt','z','png','ltdl','jpeg','tiff','agg','boost-filesystem','boost-regex']
+libraries=['rt','z','png','ltdl','jpeg','tiff','agg','boost-filesystem','boost-regex','boost-serialization']
 libpaths = [prefix+'/lib','#agg']
 linkflags = '-Wl,-rpath-link,. -Wl,-soname,libmapnik.so'
 
 source = Split(
     """
+    mapnik.cpp
     datasource_cache.cpp
     envelope.cpp
     graphics.cpp
diff --git a/src/datasource_cache.cpp b/src/datasource_cache.cpp
index 49f8f467c..63c40be6c 100644
--- a/src/datasource_cache.cpp
+++ b/src/datasource_cache.cpp
@@ -42,12 +42,12 @@ namespace mapnik
     std::map<string,boost::shared_ptr<PluginInfo> > datasource_cache::plugins_;
     bool datasource_cache::registered_=false;
         
-    datasource_p datasource_cache::create(const Parameters& params)
+    datasource_p datasource_cache::create(const parameters& params)
     {
         datasource_p ds;
         try
         {
-            std::string type=params.get("type");	    
+            const std::string type=params.get("type");	    
             map<string,boost::shared_ptr<PluginInfo> >::iterator itr=plugins_.find(type);
             if (itr!=plugins_.end())
             {
diff --git a/src/layer.cpp b/src/layer.cpp
index 57d44d664..f1fa2a602 100644
--- a/src/layer.cpp
+++ b/src/layer.cpp
@@ -18,35 +18,28 @@
 
 //$Id: layer.cpp 17 2005-03-08 23:58:43Z pavlenko $
 
-#include <string>
+
 #include "style.hpp"
 #include "datasource.hpp"
 #include "datasource_cache.hpp"
 #include "layer.hpp"
 
+#include <string>
+#include <iostream>
+
 namespace mapnik
 {
     using namespace std;
-   
-    Layer::Layer(const Parameters& params)
+    Layer::Layer() {}
+    Layer::Layer(const parameters& params)
         :params_(params),
+	 name_(params_["name"]),
 	 minZoom_(0),
 	 maxZoom_(std::numeric_limits<double>::max()),
 	 active_(true),
 	 selectable_(false),
 	 selection_style_("default_selection")
-    {
-
-        try
-        {
-            name_=params_.get("name");
-	    ds_=datasource_cache::instance()->create(params_);
-        }
-        catch (...)
-        {
-            throw;
-        }
-    }
+    {}
     
     Layer::Layer(const Layer& rhs)
         :params_(rhs.params_),
@@ -55,7 +48,7 @@ namespace mapnik
 	 maxZoom_(rhs.maxZoom_),
 	 active_(rhs.active_),
 	 selectable_(rhs.selectable_),
-	 ds_(rhs.ds_),
+	 //ds_(rhs.ds_),
 	 styles_(rhs.styles_),
 	 selection_style_(rhs.selection_style_) {}
     
@@ -79,14 +72,14 @@ namespace mapnik
         maxZoom_=rhs.maxZoom_;
         active_=rhs.active_;
         selectable_=rhs.selectable_;
-        ds_=rhs.ds_;
+        //ds_=rhs.ds_;
         styles_=rhs.styles_;
 	selection_style_=rhs.selection_style_;
     }
 
     Layer::~Layer() {}
 
-    Parameters const& Layer::params() const
+    parameters const& Layer::params() const
     {
         return params_;
     }
@@ -153,14 +146,28 @@ namespace mapnik
 
     const datasource_p& Layer::datasource() const
     {
-        return ds_;
+	if (!ds_)
+	{
+	    try
+	    {
+		ds_=datasource_cache::instance()->create(params_);
+	    }
+	    catch (...)
+	    {
+		std::cerr << "exception caught : can not create datasorce" << std::endl;  
+	    }
+	}
+	return ds_;
     }
 
     Envelope<double> Layer::envelope() const
     {
-	if (ds_)
-	    return ds_->envelope();
-	return Envelope<double>();
+	datasource_p const& ds = datasource();
+	if (ds)
+	{
+	    return ds->envelope();
+	}
+    	return Envelope<double>();
     }
 
     void Layer::selection_style(const std::string& name) 
diff --git a/src/map.cpp b/src/map.cpp
index 094f22380..5e9e833e6 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -25,12 +25,15 @@
 
 namespace mapnik
 {
-
+    Map::Map()
+	: width_(400),
+	  height_(400),
+	  srid_(-1) {}
     Map::Map(int width,int height,int srid)
         : width_(width),
-        height_(height),
-        srid_(srid),
-        background_(Color(255,255,255)) {}
+	  height_(height),
+	  srid_(srid),
+	  background_(Color(255,255,255)) {}
 
     Map::Map(const Map& rhs)
         : width_(rhs.width_),
diff --git a/src/mapnik.cpp b/src/mapnik.cpp
new file mode 100644
index 000000000..ead495613
--- /dev/null
+++ b/src/mapnik.cpp
@@ -0,0 +1,61 @@
+/* This file is part of Mapnik (c++ mapping toolkit)
+ * Copyright (C) 2005 Artem Pavlenko
+ *
+ * Mapnik is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+//$Id$
+
+#include "mapnik.hpp"
+#include <fstream>
+#include <boost/archive/text_oarchive.hpp>
+#include <boost/archive/text_iarchive.hpp>
+#include <boost/archive/xml_iarchive.hpp>
+#include <boost/archive/xml_oarchive.hpp>
+
+namespace mapnik
+{
+    void save_to_xml(Map const& m,const char* filename)
+    {
+	std::ofstream ofs(filename);
+	assert(ofs.good());
+	boost::archive::xml_oarchive oa(ofs);
+	oa << boost::serialization::make_nvp("map",m);
+    }
+    
+    void save_to_text(Map const& m,const char* filename)
+    {
+	std::ofstream ofs(filename);
+	assert(ofs.good());
+	boost::archive::text_oarchive oa(ofs);
+	oa << m;
+    }
+
+    void load_from_xml(Map & m,const char* filename)
+    {
+	std::ifstream ifs(filename);
+	assert(ifs.good());
+	boost::archive::xml_iarchive ia(ifs);
+	ia >> boost::serialization::make_nvp("map",m);
+    }
+    
+    void load_from_text(Map & m,const char* filename)
+    {
+	std::ifstream ifs(filename);
+	assert(ifs.good());
+	boost::archive::text_iarchive ia(ifs);
+	ia >> m;
+    }
+}
diff --git a/src/params.cpp b/src/params.cpp
index c7b2853b0..e5f3e65f4 100644
--- a/src/params.cpp
+++ b/src/params.cpp
@@ -18,42 +18,9 @@
 
 //$Id: params.cpp 17 2005-03-08 23:58:43Z pavlenko $
 
-#include <string>
-#include <map>
 #include "params.hpp"
 
 namespace mapnik
 {
-
-    const std::string Parameters::get(const std::string& name) const
-    {
-        std::map<std::string,std::string>::const_iterator itr;
-        itr=data_.find(name);
-        if (itr!=data_.end())
-            return itr->second;
-        return std::string();
-    }
-
-    void Parameters::add(const Parameter& param)
-    {
-        data_.insert(param);
-    }
-
-    void Parameters::add(const std::string& name,const std::string& value)
-    {
-        Parameter param(name,value);
-        data_.insert(param);
-    }
-
-    std::map<std::string,std::string>::const_iterator Parameters::begin() const
-    {
-        return data_.begin();
-    }
-
-    std::map<std::string,std::string>::const_iterator Parameters::end() const
-    {
-        return data_.end();
-    }
-
-    Parameters::~Parameters() {}
+    
 }
diff --git a/src/scanline_aa.cpp b/src/scanline_aa.cpp
index ba549fc85..937888d5b 100644
--- a/src/scanline_aa.cpp
+++ b/src/scanline_aa.cpp
@@ -603,9 +603,7 @@ namespace mapnik
             pixbuf_->blendPixel(x,y,rgba,alpha);
         }
     }
-
-
-
+    
     template <typename PixBuffer>
     inline void ScanlineRasterizerAA<PixBuffer>::render_hline(int x0,int x1,int y,unsigned rgba)
     {