--- a/cutils/shasum.py	Sun Dec 29 15:43:27 2024 +0100
+++ b/cutils/shasum.py	Sun Dec 29 17:39:00 2024 +0100
@@ -24,32 +24,14 @@
 except ImportError:
     mmap = None
 import os
-try:
-    import pathlib
-except ImportError:
-    pathlib = None
 import re
 import stat
 import sys
 
+from .util import constants
 from . import (__version__, __revision__)
 
 
-PY2 = sys.version_info[0] < 3
-
-if PY2:
-    PATH_TYPES = (unicode, str)    # noqa: F821 (undefined name 'unicode')
-else:
-    if pathlib:
-        PATH_TYPES = (str, bytes, pathlib.Path)
-    else:
-        PATH_TYPES = (str, bytes)
-
-READ_CHUNK_SIZE = 2 * 1024 * 1024    # like BUFSIZE_MAX on FreeBSD
-MAX_AUTO_MAP_SIZE = 8 * 1024 * 1024
-MAP_WINDOW_SIZE = MAX_AUTO_MAP_SIZE  # do not totally trash memory on big files
-
-
 def main(argv=None):
     aparser = argparse.ArgumentParser(
         description="Python implementation of shasum",
@@ -196,7 +178,7 @@
                         opts.base64)
     else:
         if not opts.files or (len(opts.files) == 1 and opts.files[0] == '-'):
-            if PY2:
+            if constants.PY2:
                 if sys.platform == "win32":
                     import msvcrt   # noqa: E401
                     msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
@@ -265,7 +247,7 @@
     dest = opts.dest or sys.stdout
     exit_code = 0
     if not opts.files or (len(opts.files) == 1 and opts.files[0] == '-'):
-        if PY2:
+        if constants.PY2:
             if sys.platform == "win32":
                 import os, msvcrt   # noqa: E401
                 msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
@@ -596,7 +578,7 @@
 
     """
     h = hashobj()
-    if isinstance(path, PATH_TYPES):
+    if isinstance(path, constants.PATH_TYPES):
         flags = os.O_RDONLY | getattr(os, "O_BINARY", 0) \
             | getattr(os, "O_SEQUENTIAL", 0) | getattr(os, "O_NOCTTY", 0)
         fd = os.open(path, flags)
@@ -617,7 +599,7 @@
             if stat.S_ISREG(st[stat.ST_MODE]):
                 filesize = st[stat.ST_SIZE]
                 if (use_mmap is None) \
-                        and (filesize > MAX_AUTO_MAP_SIZE):
+                        and (filesize > constants.MAX_AUTO_MAP_SIZE):
                     #
                     # This is borrowed from FreeBSD's cp(1) implementation:
                     # Mmap and process if less than 8M (the limit is
@@ -637,9 +619,9 @@
             fadvise = getattr(os, "posix_fadvise", None)
             if fadvise:
                 fadvise(fd, 0, 0, os.POSIX_FADV_SEQUENTIAL)
-            if not PY2:
+            if not constants.PY2:
                 fileobj = io.FileIO(fd, mode="r", closefd=False)
-                buf = bytearray(READ_CHUNK_SIZE)
+                buf = bytearray(constants.READ_CHUNK_SIZE)
                 with memoryview(buf) as full_view:
                     while True:
                         try:
@@ -652,7 +634,7 @@
                         else:
                             if n == 0:
                                 break
-                            if n == READ_CHUNK_SIZE:
+                            if n == constants.READ_CHUNK_SIZE:
                                 h.update(buf)
                             else:
                                 with full_view[:n] as partial_view:
@@ -660,7 +642,7 @@
             else:
                 while True:
                     try:
-                        buf = os.read(fd, READ_CHUNK_SIZE)
+                        buf = os.read(fd, constants.READ_CHUNK_SIZE)
                     except OSError as e:
                         if e.errno not in (errno.EAGAIN,
                                            errno.EWOULDBLOCK,
@@ -678,10 +660,10 @@
             #       So ensure to not call mmap.mmap() if the file size is 0.
             #
             madvise = getattr(mmap.mmap, "madvise", None)
-            if filesize <= MAP_WINDOW_SIZE:
+            if filesize <= constants.MAP_WINDOW_SIZE:
                 mapsize = filesize
             else:
-                mapsize = MAP_WINDOW_SIZE
+                mapsize = constants.MAP_WINDOW_SIZE
             mapoffset = 0
             rest = filesize
             while rest > 0:
@@ -717,7 +699,7 @@
     h = hashobj()
     while True:
         try:
-            buf = instream.read(READ_CHUNK_SIZE)
+            buf = instream.read(constants.READ_CHUNK_SIZE)
         except OSError as e:
             if e.errno not in (errno.EAGAIN, errno.EWOULDBLOCK, errno.EINTR):
                 raise

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cutils/util/constants.py	Sun Dec 29 17:39:00 2024 +0100
@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+# :-
+# :Copyright: (c) 2020-2022 Franz Glasner
+# :License:   BSD-3-Clause
+# :-
+r"""Common constants and compatibility definitions.
+
+"""
+
+__all__ = ["PY2",
+           "PATH_TYPES",
+           "READ_CHUNK_SIZE",
+           "MAX_AUTO_MAP_SIZE",
+           "MAP_WINDOW_SIZE"
+           ]
+
+
+import sys
+try:
+    import pathlib
+except ImportError:
+    pathlib = None
+
+
+PY2 = sys.version_info[0] < 3
+
+if PY2:
+    PATH_TYPES = (unicode, str)    # noqa: F821 (undefined name 'unicode')
+else:
+    if pathlib:
+        PATH_TYPES = (str, bytes, pathlib.Path)
+    else:
+        PATH_TYPES = (str, bytes)
+
+READ_CHUNK_SIZE = 2 * 1024 * 1024    # like BUFSIZE_MAX on FreeBSD
+MAX_AUTO_MAP_SIZE = 8 * 1024 * 1024
+MAP_WINDOW_SIZE = MAX_AUTO_MAP_SIZE  # do not totally trash memory on big files