Reduce configure times when regenerating clients

tools/scripts/codegen/format_util.py

@@ -9,32 +9,43 @@
 import os
 import pathlib
 import re
+import subprocess
 from subprocess import list2cmdline, run
 from tempfile import NamedTemporaryFile
 
 CLANG_FORMAT_VERSION = '18.1.6'
 CLANG_FORMAT_INCLUDE_REGEX = re.compile(r'^.*\.(cpp|h)$')
 
-
 def format_directories(directory_list):
     """Format C++ files in the given directories using clang-format"""
-    filepaths_file = NamedTemporaryFile(delete=False)
-
+    cpu_count = os.cpu_count() or 1
+
+    filepaths_files = [NamedTemporaryFile(delete=False) for _ in range(cpu_count)]
+
+    index = 0
     for root_dir in directory_list:
         if os.path.exists(root_dir):
             for dirpath, dirnames, filenames in os.walk(root_dir):
                 for filename in filenames:
                     filepath = pathlib.Path(dirpath, filename).as_posix()
                     if CLANG_FORMAT_INCLUDE_REGEX.match(filename):
-                        filepaths_file.write(f"{filepath}\n".encode())
-
-    filepaths_file.close()
-
-    cmd = ['pipx', 'run', f'clang-format=={CLANG_FORMAT_VERSION}',
-           f'--files={filepaths_file.name}', '-i', '-style=file:.clang-format']
-
-    print(f"Formatting generated files: {list2cmdline(cmd)}")
-    run(cmd)
-
+                        filepaths_files[index % cpu_count].write(f"{filepath}\n".encode())
+                        index += 1
+
+    for filepaths_file in filepaths_files:
+        filepaths_file.close()
+
+    processes = []
+    for filepaths_file in filepaths_files:
+        cmd = ['pipx', 'run', f'clang-format=={CLANG_FORMAT_VERSION}',
+               f'--files={filepaths_file.name}', '-i', '-style=file:.clang-format']
+        p = subprocess.Popen(cmd)
+        processes.append(p)
+        print(f"Formatting generated files: {list2cmdline(cmd)}")
+
+    for p in processes:
+        p.wait()
+
     # Clean up temp file
-    os.unlink(filepaths_file.name)
+    for filepaths_file in filepaths_files:
+        os.unlink(filepaths_file.name)