1 files changed, 72 insertions, 0 deletions
diff --git a/apt-pkg/pkgsystem.cc b/apt-pkg/pkgsystem.cc
new file mode 100644
index 0000000..7e48a68
--- /dev/null
+++ b/apt-pkg/pkgsystem.cc
@@ -0,0 +1,72 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/* ######################################################################
+
+   System - Abstraction for running on different systems.
+
+   Basic general structure..
+   
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <config.h>
+
+#include <apt-pkg/debsystem.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/macros.h>
+#include <apt-pkg/pkgsystem.h>
+
+#include <cassert>
+#include <cstring>
+#include <map>
+									/*}}}*/
+
+pkgSystem *_system = 0;
+static pkgSystem *SysList[10];
+pkgSystem **pkgSystem::GlobalList = SysList;
+unsigned long pkgSystem::GlobalListLen = 0;
+
+class APT_HIDDEN pkgSystemPrivate					/*{{{*/
+{
+public:
+   typedef decltype(pkgCache::Version::ID) idtype;
+   std::map<idtype,idtype> idmap;
+   pkgSystemPrivate() {}
+};
+									/*}}}*/
+// System::pkgSystem - Constructor					/*{{{*/
+// ---------------------------------------------------------------------
+/* Add it to the global list.. */
+pkgSystem::pkgSystem(char const * const label, pkgVersioningSystem * const vs) :
+   Label(label), VS(vs), d(new pkgSystemPrivate())
+{
+   assert(GlobalListLen < sizeof(SysList)/sizeof(*SysList));
+   SysList[GlobalListLen] = this;
+   ++GlobalListLen;
+}
+									/*}}}*/
+// System::GetSystem - Get the named system				/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+APT_PURE pkgSystem *pkgSystem::GetSystem(const char *Label)
+{
+   for (unsigned I = 0; I != GlobalListLen; I++)
+      if (strcmp(SysList[I]->Label,Label) == 0)
+	 return SysList[I];
+   return 0;   
+}
+									/*}}}*/
+// pkgSystem::Set/GetVersionMapping - for internal/external communication/*{{{*/
+void pkgSystem::SetVersionMapping(map_id_t const in, map_id_t const out)
+{
+   if (in == out)
+      return;
+   d->idmap.emplace(in, out);
+}
+map_id_t pkgSystem::GetVersionMapping(map_id_t const in) const
+{
+   auto const o = d->idmap.find(in);
+   return (o == d->idmap.end()) ? in : o->second;
+}
+									/*}}}*/
+pkgSystem::~pkgSystem() {}