Generalize the RotatingLogger; size, time or first of the two trigger the rollover

can/__init__.py

@@ -35,7 +35,14 @@
 from .interface import Bus, detect_available_configs
 from .bit_timing import BitTiming
 
-from .io import Logger, SizedRotatingLogger, Printer, LogReader, MessageSync
+from .io import (
+    Logger,
+    SizedRotatingLogger,
+    Printer,
+    LogReader,
+    MessageSync,
+    RotatingLogger,
+)
 from .io import ASCWriter, ASCReader
 from .io import BLFReader, BLFWriter
 from .io import CanutilsLogReader, CanutilsLogWriter

can/io/__init__.py

@@ -4,7 +4,7 @@
 """
 
 # Generic
-from .logger import Logger, BaseRotatingLogger, SizedRotatingLogger
+from .logger import Logger, BaseRotatingLogger, SizedRotatingLogger, RotatingLogger
 from .player import LogReader, MessageSync
 
 # Format specific

can/io/logger.py

@@ -6,6 +6,8 @@
 import pathlib
 from abc import ABC, abstractmethod
 from datetime import datetime
+import time
+import warnings
 import gzip
 from typing import Any, Optional, Callable, Type, Tuple, cast, Dict
 
@@ -265,11 +267,14 @@ def do_rollover(self) -> None:
         """Perform rollover."""
 
 
-class SizedRotatingLogger(BaseRotatingLogger):
-    """Log CAN messages to a sequence of files with a given maximum size.
+class RotatingLogger(BaseRotatingLogger):
+    """Log CAN messages to a sequence of files with a given maximum size,
+    a specified amount of time or a combination of both. When both max size
+    (bytes) and rollover time (seconds) are provided, the rollover trigger
+    is caused by the first to occur.
 
-    The logger creates a log file with the given `base_filename`. When the
-    size threshold is reached the current log file is closed and renamed
+    The logger creates a log file with the given `base_filename`. When a size
+    or time threshold is reached the current log file is closed and renamed
     by adding a timestamp and the rollover count. A new log file is then
     created and written to.
 
@@ -305,41 +310,61 @@ class SizedRotatingLogger(BaseRotatingLogger):
     :meth:`~can.Listener.stop` is called.
     """
 
+    last_rollover_time = time.time()
+
     def __init__(
         self,
         base_filename: StringPathLike,
-        max_bytes: int = 0,
         *args: Any,
+        max_bytes: int = 0,
+        delta_t: int = 0,
         **kwargs: Any,
     ) -> None:
         """
         :param base_filename:
-            A path-like object for the base filename. The log file format is defined by
-            the suffix of `base_filename`.
+            A path-like object for the base filename. The log file format is
+            defined by the suffix of `base_filename`.
         :param max_bytes:
-            The size threshold at which a new log file shall be created. If set to 0, no
-            rollover will be performed.
+            The size threshold at which a new log file shall be created. If set
+            less than or equal to 0, no rollover will be performed.
+        :param delta_t:
+            The elapsed time threshold at which a new log file shall be
+            created. If set less than or equal to 0, no rollover will be
+            performed.
         """
         super().__init__(*args, **kwargs)
 
         self.base_filename = os.path.abspath(base_filename)
-        self.max_bytes = max_bytes
+
+        # Rotation parameters
+        self.max_bytes = max_bytes  # Maximum bytes for rotation (bytes)
+        self.delta_t = delta_t  # Time difference between rotation (seconds)
 
         self._writer = self._get_new_writer(self.base_filename)
 
     def should_rollover(self, msg: Message) -> bool:
-        if self.max_bytes <= 0:
+        # Check to see if a file rollover should occur based on file size
+        # (bytes) and elapsed time (seconds) since last rollover.
+        if self.max_bytes <= 0 and self.delta_t <= 0:
             return False
 
-        if self.writer.file_size() >= self.max_bytes:
+        # Check to see if the file size is greater than max bytes
+        if self.writer.file_size() >= self.max_bytes > 0:
+            return True
+        # Check to see if elapsed time is greater than delta_t
+        if time.time() - self.last_rollover_time > self.delta_t > 0:
             return True
 
         return False
 
     def do_rollover(self) -> None:
+        # Perform the file rollover.
         if self.writer:
             self.writer.stop()
 
+        # Reset the time since last rollover
+        self.last_rollover_time = time.time()
+
         sfn = self.base_filename
         dfn = self.rotation_filename(self._default_name())
         self.rotate(sfn, dfn)
@@ -350,11 +375,77 @@ def _default_name(self) -> StringPathLike:
         """Generate the default rotation filename."""
         path = pathlib.Path(self.base_filename)
         new_name = (
-            path.stem.split(".")[0]
+            path.stem
             + "_"
             + datetime.now().strftime("%Y-%m-%dT%H%M%S")
             + "_"
             + f"#{self.rollover_count:03}"
-            + "".join(path.suffixes[-2:])
+            + path.suffix
         )
         return str(path.parent / new_name)
+
+
+class SizedRotatingLogger(RotatingLogger):
+    """Log CAN messages to a sequence of files with a given maximum size.
+
+    The logger creates a log file with the given `base_filename`. When the
+    size threshold is reached the current log file is closed and renamed
+    by adding a timestamp and the rollover count. A new log file is then
+    created and written to.
+
+    This behavior can be customized by setting the :attr:`namer` and
+    :attr:`rotator` attribute.
+
+    Example::
+
+        from can import Notifier, SizedRotatingLogger
+        from can.interfaces.vector import VectorBus
+
+        bus = VectorBus(channel=[0], app_name="CANape", fd=True)
+
+        logger = SizedRotatingLogger(
+            base_filename="my_logfile.asc",
+            max_bytes=5 * 1024 ** 2,  # =5MB
+        )
+        logger.rollover_count = 23  # start counter at 23
+
+        notifier = Notifier(bus=bus, listeners=[logger])
+
+    The SizedRotatingLogger currently supports the formats
+      * .asc: :class:`can.ASCWriter`
+      * .blf :class:`can.BLFWriter`
+      * .csv: :class:`can.CSVWriter`
+      * .log :class:`can.CanutilsLogWriter`
+      * .txt :class:`can.Printer` (if pointing to a file)
+
+    .. note::
+        The :class:`can.SqliteWriter` is not supported yet.
+
+    The log files on disk may be incomplete due to buffering until
+    :meth:`~can.Listener.stop` is called.
+    """
+
+    def __init__(
+        self,
+        base_filename: StringPathLike,
+        max_bytes: int = 0,
+        *args: Any,
+        **kwargs: Any,
+    ) -> None:
+        """
+        :param base_filename:
+            A path-like object for the base filename. The log file format is defined by
+            the suffix of `base_filename`.
+        :param max_bytes:
+            The size threshold at which a new log file shall be created. If set to 0, no
+            rollover will be performed.
+        """
+        # This object is deprecated as of 4.1 and will be removed in 5.0.
+        warnings.simplefilter("always", DeprecationWarning)
+        warnings.warn(
+            "SizedRotatingLogger is being replaced with the "
+            "generalized RotatingLogger in python-can 5.0.",
+            DeprecationWarning,
+        )
+        # Initialize self as a RotatingLogger
+        super().__init__(base_filename, *args, max_bytes=max_bytes, **kwargs)

can/logger.py

@@ -23,7 +23,7 @@
 import can
 from can.io import BaseRotatingLogger
 from can.io.generic import MessageWriter
-from . import Bus, BusState, Logger, SizedRotatingLogger
+from . import Bus, BusState, Logger, RotatingLogger
 from .typechecking import CanFilter, CanFilters
 
 
@@ -196,7 +196,16 @@ def main() -> None:
         help="Maximum file size in bytes (or for the case of blf, maximum "
         "buffer size before compression and flush to file). Rotate log "
         "file when size threshold is reached.",
-        default=None,
+        default=0,
+    )
+
+    parser.add_argument(
+        "-t",
+        "--time_difference",
+        dest="delta_t",
+        type=int,
+        help="Time difference in seconds between file rollover.",
+        default=0,
     )
 
     parser.add_argument(
@@ -239,9 +248,10 @@ def main() -> None:
 
     logger: Union[MessageWriter, BaseRotatingLogger]
     if results.file_size:
-        logger = SizedRotatingLogger(
+        logger = RotatingLogger(
             base_filename=results.log_file,
             max_bytes=results.file_size,
+            delta_t=results.delta_t,
             append=results.append,
             **additional_config,
         )

test/test_logger.py

@@ -103,7 +103,7 @@ def test_log_virtual_sizedlogger(self):
         self.MockLoggerUse = self.MockLoggerSized
         self.loggerToUse = self.mock_logger_sized
 
-        sys.argv = self.baseargs + ["--file_size", "1000000"]
+        sys.argv = self.baseargs + ["-f file.log"] + ["--file_size", "1000000"]
         can.logger.main()
         self.assertSuccessfullCleanup()
         self.mock_logger_sized.assert_called_once()