intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 86 insertions, 0 deletions

diff --git a/library/cpp/logger/rotating_file.cpp b/library/cpp/logger/rotating_file.cpp
new file mode 100644
index 0000000000..a62f48f25d
--- /dev/null
+++ b/library/cpp/logger/rotating_file.cpp
@@ -0,0 +1,86 @@
+#include "rotating_file.h"
+#include "file.h"
+#include "record.h"
+
+#include <util/string/builder.h>
+#include <util/system/fstat.h>
+#include <util/system/rwlock.h>
+#include <util/system/fs.h>
+#include <util/system/atomic.h>
+#include <util/generic/string.h>
+
+/*
+ * rotating file log
+ * if Size_ > MaxSizeBytes
+ *    Path.(N-1) -> Path.N
+ *    Path.(N-2) -> Path.(N-1)
+ *    ...
+ *    Path.1     -> Path.2
+ *    Path       -> Path.1
+ */
+class TRotatingFileLogBackend::TImpl {
+public:
+    inline TImpl(const TString& path, const ui64 maxSizeBytes, const ui32 rotatedFilesCount)
+        : Log_(path)
+        , Path_(path)
+        , MaxSizeBytes_(maxSizeBytes)
+        , Size_(TFileStat(Path_).Size)
+        , RotatedFilesCount_(rotatedFilesCount)
+    {
+        Y_ENSURE(RotatedFilesCount_ != 0);
+    }
+
+    inline void WriteData(const TLogRecord& rec) {
+        if (static_cast<ui64>(AtomicGet(Size_)) > MaxSizeBytes_) {
+            TWriteGuard guard(Lock_);
+            if (static_cast<ui64>(AtomicGet(Size_)) > MaxSizeBytes_) {
+                TString newLogPath(TStringBuilder{} << Path_ << "." << RotatedFilesCount_);
+                for (size_t fileId = RotatedFilesCount_ - 1; fileId; --fileId) {
+                    TString oldLogPath(TStringBuilder{} << Path_ << "." << fileId);
+                    NFs::Rename(oldLogPath, newLogPath);
+                    newLogPath = oldLogPath;
+                }
+                NFs::Rename(Path_, newLogPath);
+                Log_.ReopenLog();
+                AtomicSet(Size_, 0);
+            }
+        }
+        TReadGuard guard(Lock_);
+        Log_.WriteData(rec);
+        AtomicAdd(Size_, rec.Len);
+    }
+
+    inline void ReopenLog() {
+        TWriteGuard guard(Lock_);
+
+        Log_.ReopenLog();
+        AtomicSet(Size_, TFileStat(Path_).Size);
+    }
+
+private:
+    TRWMutex Lock_;
+    TFileLogBackend Log_;
+    const TString Path_;
+    const ui64 MaxSizeBytes_;
+    TAtomic Size_;
+    const ui32 RotatedFilesCount_;
+};
+
+TRotatingFileLogBackend::TRotatingFileLogBackend(const TString& path, const ui64 maxSizeByte, const ui32 rotatedFilesCount)
+    : Impl_(new TImpl(path, maxSizeByte, rotatedFilesCount))
+{
+}
+
+TRotatingFileLogBackend::~TRotatingFileLogBackend() {
+}
+
+void TRotatingFileLogBackend::WriteData(const TLogRecord& rec) {
+    Impl_->WriteData(rec);
+}
+
+void TRotatingFileLogBackend::ReopenLog() {
+    TAtomicSharedPtr<TImpl> copy = Impl_;
+    if (copy) {
+        copy->ReopenLog();
+    }
+}