intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 30 insertions, 0 deletions

diff --git a/library/cpp/logger/backend.h b/library/cpp/logger/backend.h
new file mode 100644
index 0000000000..d088726d6d
--- /dev/null
+++ b/library/cpp/logger/backend.h
@@ -0,0 +1,30 @@
+#pragma once
+
+#include "priority.h"
+
+#include <util/generic/noncopyable.h>
+
+#include <cstddef>
+
+struct TLogRecord;
+
+// NOTE: be aware that all `TLogBackend`s are registred in singleton.
+class TLogBackend: public TNonCopyable {
+public:
+    TLogBackend() noexcept;
+    virtual ~TLogBackend();
+
+    virtual void WriteData(const TLogRecord& rec) = 0;
+    virtual void ReopenLog() = 0;
+
+    // Does not guarantee consistency with previous WriteData() calls:
+    // log entries could be written to the new (reopened) log file due to
+    // buffering effects.
+    virtual void ReopenLogNoFlush();
+
+    virtual ELogPriority FiltrationLevel() const;
+
+    static void ReopenAllBackends(bool flush = true);
+
+    virtual size_t QueueSize() const;
+};