X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=src%2Fstlplus%2Fpersistence%2Fpersistent_pointer.tpp;fp=src%2Fstlplus%2Fpersistence%2Fpersistent_pointer.tpp;h=c760b17c36b34ac9a946ed5a6d38920267c39e45;hb=6b0a0d0efafe34d48ab344fca3b479553bd4e62c;hp=0000000000000000000000000000000000000000;hpb=85783316365181491a3e3c0c63659972477cebba;p=chaz%2Fyoink

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