RAHHH

backend/lib/python3.12/site-packages/twisted/logger/_file.py

@@ -0,0 +1,77 @@
+# -*- test-case-name: twisted.logger.test.test_file -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+File log observer.
+"""
+
+from typing import IO, Any, Callable, Optional
+
+from zope.interface import implementer
+
+from twisted.python.compat import ioType
+from ._format import formatEventAsClassicLogText, formatTime, timeFormatRFC3339
+from ._interfaces import ILogObserver, LogEvent
+
+
+@implementer(ILogObserver)
+class FileLogObserver:
+    """
+    Log observer that writes to a file-like object.
+    """
+
+    def __init__(
+        self, outFile: IO[Any], formatEvent: Callable[[LogEvent], Optional[str]]
+    ) -> None:
+        """
+        @param outFile: A file-like object.  Ideally one should be passed which
+            accepts text data.  Otherwise, UTF-8 L{bytes} will be used.
+        @param formatEvent: A callable that formats an event.
+        """
+        if ioType(outFile) is not str:
+            self._encoding: Optional[str] = "utf-8"
+        else:
+            self._encoding = None
+
+        self._outFile = outFile
+        self.formatEvent = formatEvent
+
+    def __call__(self, event: LogEvent) -> None:
+        """
+        Write event to file.
+
+        @param event: An event.
+        """
+        text = self.formatEvent(event)
+
+        if text:
+            if self._encoding is None:
+                self._outFile.write(text)
+            else:
+                self._outFile.write(text.encode(self._encoding))
+            self._outFile.flush()
+
+
+def textFileLogObserver(
+    outFile: IO[Any], timeFormat: Optional[str] = timeFormatRFC3339
+) -> FileLogObserver:
+    """
+    Create a L{FileLogObserver} that emits text to a specified (writable)
+    file-like object.
+
+    @param outFile: A file-like object.  Ideally one should be passed which
+        accepts text data.  Otherwise, UTF-8 L{bytes} will be used.
+    @param timeFormat: The format to use when adding timestamp prefixes to
+        logged events.  If L{None}, or for events with no C{"log_timestamp"}
+        key, the default timestamp prefix of C{"-"} is used.
+
+    @return: A file log observer.
+    """
+
+    def formatEvent(event: LogEvent) -> Optional[str]:
+        return formatEventAsClassicLogText(
+            event, formatTime=lambda e: formatTime(e, timeFormat)
+        )
+
+    return FileLogObserver(outFile, formatEvent)