Support zstd compression

Author: dsseng

can/io/logger.py

@@ -42,6 +42,12 @@
 from .sqlite import SqliteWriter
 from .trc import TRCWriter
 
+try:
+    import pyzstd
+except ImportError:
+    pyzstd = None
+
+
 #: A map of file suffixes to their corresponding
 #: :class:`can.io.generic.MessageWriter` class
 MESSAGE_WRITERS: Final[Dict[str, Type[MessageWriter]]] = {
@@ -103,7 +109,16 @@ def _compress(
     else:
         mode = "at" if append else "wt"
 
-    return logger_type, gzip.open(filename, mode)
+    if suffixes[-1] == ".gz":
+        compressor = gzip.open(filename, mode)
+    elif suffixes[-1] == ".zst" and pyzstd is not None:
+        compressor = pyzstd.open(filename, mode)
+    else:
+        raise ValueError(
+            f"Unknown compression type {suffixes[-1]} in {filename}, maybe a dependency is missing?"
+        )
+
+    return logger_type, compressor
 
 
 def Logger(  # noqa: N802
@@ -125,7 +140,8 @@ def Logger(  # noqa: N802
 
     Any of these formats can be used with gzip compression by appending
     the suffix .gz (e.g. filename.asc.gz). However, third-party tools might not
-    be able to read these files.
+    be able to read these files. Zstandard (.zst) compression is also supported
+    when an optional dependency is installed.
 
     The **filename** may also be *None*, to fall back to :class:`can.Printer`.
 
@@ -150,7 +166,7 @@ def Logger(  # noqa: N802
 
     suffix = pathlib.PurePath(filename).suffix.lower()
     file_or_filename: AcceptedIOType = filename
-    if suffix == ".gz":
+    if suffix in (".gz", ".zst"):
         logger_type, file_or_filename = _compress(filename, **kwargs)
     else:
         logger_type = _get_logger_for_suffix(suffix)

can/io/player.py

@@ -31,6 +31,12 @@
 from .sqlite import SqliteReader
 from .trc import TRCReader
 
+try:
+    import pyzstd
+except ImportError:
+    pyzstd = None
+
+
 #: A map of file suffixes to their corresponding
 #: :class:`can.io.generic.MessageReader` class
 MESSAGE_READERS: Final[Dict[str, Type[MessageReader]]] = {
@@ -81,7 +87,16 @@ def _decompress(
 
     mode = "rb" if issubclass(reader_type, BinaryIOMessageReader) else "rt"
 
-    return reader_type, gzip.open(filename, mode)
+    if suffixes[-1] == ".gz":
+        decompressor = gzip.open(filename, mode)
+    elif suffixes[-1] == ".zst" and pyzstd is not None:
+        decompressor = pyzstd.open(filename, mode)
+    else:
+        raise ValueError(
+            f"Unknown compression type {suffixes[-1]} in {filename}, maybe a dependency is missing?"
+        )
+
+    return reader_type, decompressor
 
 
 def LogReader(filename: StringPathLike, **kwargs: Any) -> MessageReader:  # noqa: N802
@@ -98,7 +113,7 @@ def LogReader(filename: StringPathLike, **kwargs: Any) -> MessageReader:  # noqa
         (optional, depends on `asammdf <https://github.com/danielhrisca/asammdf>`_)
       * .trc :class:`can.TRCReader`
 
-    Gzip compressed files can be used as long as the original
+    Gzip and Zstd compressed files can be used as long as the original
     files suffix is one of the above (e.g. filename.asc.gz).
 
 
@@ -125,7 +140,7 @@ def LogReader(filename: StringPathLike, **kwargs: Any) -> MessageReader:  # noqa
 
     suffix = pathlib.PurePath(filename).suffix.lower()
     file_or_filename: AcceptedIOType = filename
-    if suffix == ".gz":
+    if suffix in (".gz", ".zst"):
         reader_type, file_or_filename = _decompress(filename)
     else:
         reader_type = _get_logger_for_suffix(suffix)

pyproject.toml

@@ -84,6 +84,7 @@ viewer = [
 ]
 mf4 = ["asammdf>=6.0.0"]
 pcapng = ["python-pcapng>=2.1.1"]
+zstd = ["pyzstd>=0.16.2"]
 
 [tool.setuptools.dynamic]
 readme = { file = "README.rst" }