add extra_log.h12.5

1 files changed, 84 insertions, 0 deletions

diff --git a/zen/extra_log.h b/zen/extra_log.h
new file mode 100644
index 00000000..3928d0f1
--- /dev/null
+++ b/zen/extra_log.h
@@ -0,0 +1,84 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#ifndef EXTRA_LOG_H_601673246392441846218957402563
+#define EXTRA_LOG_H_601673246392441846218957402563
+
+#include "error_log.h"
+#include "thread.h"
+
+/*  log errors in "exceptional situations" when no other means are available, e.g.
+    - while an exception is in flight
+    - cleanup errors
+    - nothrow GUI functions                                */
+
+namespace zen
+{
+namespace impl
+{
+class ExtraLog
+{
+public:
+    ~ExtraLog()
+    {
+        assert(reportOutstandingLog_);
+        if (!log_.empty() && reportOutstandingLog_)
+            reportOutstandingLog_(log_);
+    }
+
+    void init(const std::function<void(const ErrorLog& log)>& reportOutstandingLog)
+    {
+        assert(!reportOutstandingLog_);
+        reportOutstandingLog_ = reportOutstandingLog;
+    }
+
+    ErrorLog fetchLog() { return std::exchange(log_, ErrorLog()); }
+
+    void logError(const std::wstring& msg) { logMsg(log_, msg, MessageType::MSG_TYPE_ERROR); } //nothrow!
+
+private:
+    ErrorLog log_;
+    std::function<void(const ErrorLog& log)> reportOutstandingLog_;
+};
+
+inline constinit Global<Protected<ExtraLog>> globalExtraLog;
+
+template <class Function>
+auto accessExtraLog(Function fun)
+{
+    globalExtraLog.setOnce([] { return std::make_unique<Protected<ExtraLog>>(); });
+
+    if (auto protExtraLog = impl::globalExtraLog.get())
+        protExtraLog->access([&](ExtraLog& log) { fun(log); });
+    else
+        assert(false); //access after global shutdown!? => SOL!
+}
+}
+
+inline
+void initExtraLog(const std::function<void(const ErrorLog& log)>& reportOutstandingLog /*nothrow! runs during global shutdown!*/)
+{
+    impl::accessExtraLog([&](impl::ExtraLog& el) { el.init(reportOutstandingLog); });
+}
+
+
+inline
+ErrorLog fetchExtraLog()
+{
+    ErrorLog output;
+    impl::accessExtraLog([&](impl::ExtraLog& el) { output = el.fetchLog(); });
+    return output;
+}
+
+
+inline
+void logExtraError(const std::wstring& msg) //nothrow!
+{
+    impl::accessExtraLog([&](impl::ExtraLog& el) { el.logError(msg); });
+}
+}
+
+#endif //EXTRA_LOG_H_601673246392441846218957402563