1 files changed, 50 insertions, 0 deletions
diff --git a/src/Agent.App/Logging/RollingFileWriter.cs b/src/Agent.App/Logging/RollingFileWriter.cs
new file mode 100644
index 0000000..e155858
--- /dev/null
+++ b/src/Agent.App/Logging/RollingFileWriter.cs
@@ -0,0 +1,50 @@
+using System.Text;
+
+namespace Agent.App.Logging;
+
+internal sealed class RollingFileWriter : IDisposable
+{
+    private readonly object _sync = new();
+    private readonly string _path;
+    private readonly long _maxBytes;
+    private readonly int _retainedFiles;
+    private StreamWriter _writer;
+
+    public RollingFileWriter(string path, long maxBytes, int retainedFiles)
+    {
+        _path = path;
+        _maxBytes = maxBytes;
+        _retainedFiles = retainedFiles;
+        Directory.CreateDirectory(Path.GetDirectoryName(path)!);
+        _writer = Open();
+    }
+
+    public void WriteLine(string line)
+    {
+        lock (_sync)
+        {
+            if (_writer.BaseStream.Length >= _maxBytes) Rotate();
+            _writer.WriteLine(line);
+            _writer.Flush();
+        }
+    }
+
+    private StreamWriter Open() => new(new FileStream(_path, FileMode.Append, FileAccess.Write, FileShare.Read), new UTF8Encoding(false));
+
+    private void Rotate()
+    {
+        _writer.Dispose();
+        for (int index = _retainedFiles - 1; index >= 1; index--)
+        {
+            string source = $"{_path}.{index}";
+            if (File.Exists(source)) File.Move(source, $"{_path}.{index + 1}", true);
+        }
+        if (File.Exists(_path)) File.Move(_path, $"{_path}.1", true);
+        _writer = Open();
+    }
+
+    public void Dispose()
+    {
+        lock (_sync) _writer.Dispose();
+    }
+}