Support for schema evolution using substitution groups

New examples: hybrid/evolution/ignore and hybrid/evolution/passthrough.

5 files changed, 136 insertions, 61 deletions

diff --git a/libxsde/xsde/cxx/serializer/genx/document.cxx b/libxsde/xsde/cxx/serializer/genx/document.cxx
index 4c634a4..e8cacc0 100644
--- a/libxsde/xsde/cxx/serializer/genx/document.cxx
+++ b/libxsde/xsde/cxx/serializer/genx/document.cxx
@@ -514,7 +514,7 @@ namespace xsde
             // Call to check sets ns and n if successful.
             //
             if (strcmp (dt, root_static_type_) == 0 ||
-                substitution_map_instance ().check (ns, n, dt))
+                substitution_map_instance ().check (ns, n, dt, 0))
               dt = 0;
           }
 
diff --git a/libxsde/xsde/cxx/serializer/substitution-map-callback.hxx b/libxsde/xsde/cxx/serializer/substitution-map-callback.hxx
new file mode 100644
index 0000000..c29a00d
--- /dev/null
+++ b/libxsde/xsde/cxx/serializer/substitution-map-callback.hxx
@@ -0,0 +1,26 @@
+// file      : xsde/cxx/serializer/substitution-map-callback.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2005-2010 Code Synthesis Tools CC
+// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+#ifndef XSDE_CXX_SERIALIZER_SUBSTITUTION_MAP_CALLBACK_HXX
+#define XSDE_CXX_SERIALIZER_SUBSTITUTION_MAP_CALLBACK_HXX
+
+namespace xsde
+{
+  namespace cxx
+  {
+    namespace serializer
+    {
+      void
+      serializer_smap_callback (
+        bool (*callback) (
+          const char* type,
+          const void* obj,
+          const char*& ns,
+          const char*& name));
+    }
+  }
+}
+
+#endif  // XSDE_CXX_SERIALIZER_SUBSTITUTION_MAP_CALLBACK_HXX
diff --git a/libxsde/xsde/cxx/serializer/substitution-map.cxx b/libxsde/xsde/cxx/serializer/substitution-map.cxx
index 28f01b5..dc73fd2 100644
--- a/libxsde/xsde/cxx/serializer/substitution-map.cxx
+++ b/libxsde/xsde/cxx/serializer/substitution-map.cxx
@@ -17,6 +17,7 @@
 #endif
 
 #include <xsde/cxx/serializer/substitution-map.hxx>
+#include <xsde/cxx/serializer/substitution-map-callback.hxx>
 #include <xsde/cxx/serializer/substitution-map-load.hxx>
 
 namespace xsde
@@ -103,8 +104,19 @@ namespace xsde
       bool substitution_map::
       check_ (const char*& ns,
               const char*& name,
-              const char* type) const
+              const char* type,
+              const void* obj,
+              bool top) const
       {
+        // Call the callback first to allow the user to provide a custom
+        // substitution group mapping.
+        //
+        if (top && callback_ != 0)
+        {
+          if (callback_ (type, obj, ns, name))
+            return true;
+        }
+
         size_t h = hash (name);
 
         if (ns)
@@ -115,70 +127,70 @@ namespace xsde
 
         const bucket* p = find (h);
 
-        if (p == 0)
-          return false;
-
-        // Search for the entry in the bucket.
-        //
-        const size_t el_size = sizeof (element) + sizeof (hashmap*);
-        const char* b = reinterpret_cast<const char*> (p) + sizeof (bucket);
-        const char* e = b + p->size_ * el_size;
-
-        size_t nl = ns ? strlen (name) : 0;
-
-        for (; b < e; b += el_size)
+        if (p != 0)
         {
-          const element* e = reinterpret_cast<const element*> (b);
+          // Search for the entry in the bucket.
+          //
+          const size_t el_size = sizeof (element) + sizeof (hashmap*);
+          const char* b = reinterpret_cast<const char*> (p) + sizeof (bucket);
+          const char* e = b + p->size_ * el_size;
+
+          size_t nl = ns ? strlen (name) : 0;
 
-          if (e->hash_ == h)
+          for (; b < e; b += el_size)
           {
-            if (ns == 0)
-            {
-              if (strcmp (e->key_, name) == 0)
-                break;
-            }
-            else
+            const element* e = reinterpret_cast<const element*> (b);
+
+            if (e->hash_ == h)
             {
-              if (strncmp (e->key_, name, nl) == 0 &&
-                  e->key_[nl] == ' ' &&
-                  strcmp (e->key_ + nl + 1, ns) == 0)
-                break;
+              if (ns == 0)
+              {
+                if (strcmp (e->key_, name) == 0)
+                  break;
+              }
+              else
+              {
+                if (strncmp (e->key_, name, nl) == 0 &&
+                    e->key_[nl] == ' ' &&
+                    strcmp (e->key_ + nl + 1, ns) == 0)
+                  break;
+              }
             }
           }
-        }
 
-        if (b == e)
-          return false;
-
-        const hashmap* map = *reinterpret_cast<const hashmap* const*> (
-          b + sizeof (element));
+          if (b != e)
+          {
+            const hashmap* map = *reinterpret_cast<const hashmap* const*> (
+              b + sizeof (element));
 
-        // See if we have a direct substitution.
-        //
-        if (const value* v = static_cast<const value*> (map->find (type)))
-        {
-          ns = v->ns_;
-          name = v->name_;
-          return true;
-        }
+            // See if we have a direct substitution.
+            //
+            if (const value* v = static_cast<const value*> (map->find (type)))
+            {
+              ns = v->ns_;
+              name = v->name_;
+              return true;
+            }
 
-        // Otherwise we have to iterate over possible substitutions and
-        // see if any of them can in turn be substituted with something
-        // that we can use.
-        //
-        for (const_iterator i (map->begin ()), end (map->end ());
-             i != end; ++i)
-        {
-          const value* v = static_cast<const value*> (*i);
+            // Otherwise we have to iterate over possible substitutions and
+            // see if any of them can in turn be substituted with something
+            // that we can use.
+            //
+            for (const_iterator i (map->begin ()), end (map->end ());
+                 i != end; ++i)
+            {
+              const value* v = static_cast<const value*> (*i);
 
-          const char* tns = v->ns_;
-          const char* tn = v->name_;
+              const char* tns = v->ns_;
+              const char* tn = v->name_;
 
-          if (check_ (tns, tn, type))
-          {
-            ns = tns;
-            name = tn;
-            return true;
+              if (check_ (tns, tn, type, obj, false))
+              {
+                ns = tns;
+                name = tn;
+                return true;
+              }
+            }
           }
         }
 
@@ -264,7 +276,20 @@ namespace xsde
 #endif
       }
 
+      // Callback.
       //
+      void
+      serializer_smap_callback (
+        bool (*callback) (
+          const char* type,
+          const void* obj,
+          const char*& ns,
+          const char*& name))
+      {
+        substitution_map_instance ().callback (callback);
+      }
+
+      // Load.
       //
       size_t
       serializer_smap_elements ()
diff --git a/libxsde/xsde/cxx/serializer/substitution-map.hxx b/libxsde/xsde/cxx/serializer/substitution-map.hxx
index ae16f4c..e36c481 100644
--- a/libxsde/xsde/cxx/serializer/substitution-map.hxx
+++ b/libxsde/xsde/cxx/serializer/substitution-map.hxx
@@ -30,21 +30,34 @@ namespace xsde
                 const char* member_name,
                 const char* member_type);
 
+        typedef bool (*callback_func) (
+          const char* type,
+          const void* obj,
+          const char*& ns,
+          const char*& name);
+
+        void
+        callback (callback_func);
+
         // Check whether there is a substitution available for this
         // root element with the specified type. If so, return true
         // and override namespace and name (ns is 0 if there is no
-        // namespace).
+        // namespace). The obj argument is an opaque pointer to the
+        // instance being serialized or 0 if there is none.
         //
         bool
         check (const char*& ns,
                const char*& name,
-               const char* type) const;
+               const char* type,
+               const void* obj) const;
 
       private:
         bool
         check_ (const char*& ns,
                 const char*& name,
-                const char* type) const;
+                const char* type,
+                const void* obj,
+                bool top) const;
 
       private:
         struct value
@@ -52,6 +65,9 @@ namespace xsde
           const char* ns_;
           const char* name_;
         };
+
+      private:
+        callback_func callback_;
       };
 
 
@@ -85,4 +101,3 @@ namespace xsde
 #include <xsde/cxx/serializer/substitution-map.ixx>
 
 #endif  // XSDE_CXX_SERIALIZER_SUBSTITUTION_MAP_HXX
-
diff --git a/libxsde/xsde/cxx/serializer/substitution-map.ixx b/libxsde/xsde/cxx/serializer/substitution-map.ixx
index 6622e33..6dbd951 100644
--- a/libxsde/xsde/cxx/serializer/substitution-map.ixx
+++ b/libxsde/xsde/cxx/serializer/substitution-map.ixx
@@ -15,12 +15,21 @@ namespace xsde
       {
       }
 
+      inline void substitution_map::
+      callback (callback_func c)
+      {
+        callback_ = c;
+      }
+
       inline bool substitution_map::
       check (const char*& ns,
              const char*& name,
-             const char* type) const
+             const char* type,
+             const void* obj) const
       {
-        return empty () ? false : check_ (ns, name, type);
+        return !empty () || callback_ != 0
+          ? check_ (ns, name, type, obj, true)
+          : false;
       }
 
       inline substitution_map&