testing new non-autotools build system

[chaz/yoink] / src / stlplus / persistence / persistent_pointer.tpp

diff --git a/src/stlplus/persistence/persistent_pointer.tpp b/src/stlplus/persistence/persistent_pointer.tpp
new file mode 100644 (file)
index 0000000..c760b17
--- /dev/null
+++ b/src/stlplus/persistence/persistent_pointer.tpp
@@ -0,0 +1,68 @@
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+//   Author:    Andy Rushton\r
+//   Copyright: (c) Southampton University 1999-2004\r
+//              (c) Andy Rushton           2004-2009\r
+//   License:   BSD License, see ../docs/license.html\r
+\r
+//   format: magic_key [ data ]\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+#include "persistent_int.hpp"\r
+\r
+namespace stlplus\r
+{\r
+\r
+  ////////////////////////////////////////////////////////////////////////////////\r
+\r
+  template<typename T, typename D>\r
+  void dump_pointer(dump_context& context, const T* const data, D dump_fn)\r
+    throw(persistent_dump_failed)\r
+  {\r
+    // register the address and get the magic key for it\r
+    std::pair<bool,unsigned> mapping = context.pointer_map(data);\r
+    dump_unsigned(context,mapping.second);\r
+    // if the address is null, then that is all that we need to do\r
+    // however, if it is non-null and this is the first sight of the address, dump the contents\r
+    // note that the address is mapped before it is dumped so that self-referential structures dump correctly\r
+    if (data && !mapping.first)\r
+      dump_fn(context,*data);\r
+  }\r
+\r
+  ////////////////////////////////////////////////////////////////////////////////\r
+\r
+  template<typename T, typename R>\r
+  void restore_pointer(restore_context& context, T*& data, R restore_fn)\r
+    throw(persistent_restore_failed)\r
+  {\r
+    if (data)\r
+    {\r
+      delete data;\r
+      data = 0;\r
+    }\r
+    // get the magic key\r
+    unsigned magic = 0;\r
+    restore_unsigned(context,magic);\r
+    // now lookup the magic key to see if this pointer has already been restored\r
+    // null pointers are always flagged as already restored\r
+    std::pair<bool,void*> address = context.pointer_map(magic);\r
+    if (address.first)\r
+    {\r
+      // seen before, so simply assign the old address\r
+      data = (T*)address.second;\r
+    }\r
+    else\r
+    {\r
+      // this pointer has never been seen before and is non-null\r
+      data = new T();\r
+      // add this pointer to the set of already seen objects\r
+      // do this before restoring the object so that self-referential structures restore correctly\r
+      context.pointer_add(magic,data);\r
+      // now restore it\r
+      restore_fn(context,*data);\r
+    }\r
+  }\r
+\r
+  ////////////////////////////////////////////////////////////////////////////////\r
+\r
+} // end namespace stlplus\r