fix: parallelization effort, progressbar w/ bit-identitical file write compared to sequential path

libray/core.py

@@ -24,6 +24,7 @@ import sys
 import stat
 import zlib
 import shutil
+import threading
 import requests
 from bs4 import BeautifulSoup
 from typing import Any, Optional
@@ -99,14 +100,14 @@ def error(msg: str) -> None:
     sys.exit(1)
 
 
-def warning(msg: str, args) -> None:
+def warning(msg: str, args: Any) -> None:
     """Print a warning message. Warning messages can be silenced with --quiet"""
 
     if not args.quiet:
         print(f'[WARNING] {msg}. Continuing regardless.', file=sys.stderr)
 
 
-def vprint(msg: str, args) -> None:
+def vprint(msg: str, args: Any) -> None:
     """Vprint, verbose print, can be silenced with --quiet"""
 
     if not args.quiet:
@@ -151,22 +152,24 @@ def ird_by_game_id(game_id: str) -> Optional[str]:
     return (ird_name)
 
 
-def crc32(filename: str, keep_going: Optional[list] = None) -> Optional[str]:
-    """Calculate crc32 for file"""
-    if keep_going is None:
-        keep_going = [True]
+def crc32(filename: str, cancel: Optional[threading.Event] = None) -> Optional[str]:
+    """Calculate crc32 for file.
+
+    If *cancel* is provided, the computation can be aborted from another
+    thread by calling ``cancel.set()``.  Returns ``None`` when cancelled.
+    """
+    if cancel is None:
+        cancel = threading.Event()
 
     with open(filename, 'rb') as infile:
-
         crc_val = 0
-
-        while keep_going[0] is True:
+        while not cancel.is_set():
             data = infile.read(65536)
             if not data:
                 break
             crc_val = zlib.crc32(data, crc_val)
 
-        if keep_going[0] is False:
+        if cancel.is_set():
             return None
 
         return f"{crc_val & 0xFFFFFFFF:08X}"