PERF: implement multi-threading parallelism in inifix-validate CLI

src/inifix/validate.py

@@ -3,7 +3,10 @@
 import argparse
 import os
 import sys
+from concurrent.futures import ThreadPoolExecutor
+from typing import Literal
 
+from inifix._cli import Message, TaskResults
 from inifix.io import load
 
 
@@ -12,21 +15,33 @@ def main(argv: list[str] | None = None) -> int:
     parser.add_argument("files", nargs="+")
 
     args = parser.parse_args(argv)
-    retv = 0
-    for file in args.files:
-        if not os.path.isfile(file):
-            print(f"Error: could not find {file}", file=sys.stderr)
-            retv = 1
-            continue
-        try:
-            load(file)
-        except ValueError as exc:
-            print(f"Failed to validate {file}:\n  {exc}", file=sys.stderr)
-            retv = 1
-        else:
-            print(f"Validated {file}")
-
-    return retv
+    closure = _validate_single_file_cli
+    with ThreadPoolExecutor(max_workers=int((os.cpu_count() or 2) / 2)) as executor:
+        futures = [executor.submit(closure, file) for file in args.files]
+        results = [f.result() for f in futures]
+
+    for res in results:
+        for message in res.messages:
+            print(message.content, file=message.dest)
+
+    return max(res.status for res in results)
+
+
+def _validate_single_file_cli(file: str) -> TaskResults:
+    status: Literal[0, 1] = 0
+    messages: list[Message] = []
+    if not os.path.isfile(file):
+        status = 1
+        messages.append(Message(f"Error: could not find {file}", sys.stderr))
+        return TaskResults(status, messages)
+    try:
+        load(file)
+    except ValueError as exc:
+        status = 1
+        messages.append(Message(f"Failed to validate {file}:\n  {exc}", sys.stderr))
+    else:
+        messages.append(Message(f"Validated {file}", sys.stdout))
+    return TaskResults(status, messages)
 
 
 if __name__ == "__main__":  # pragma: no cover