need this too

diff --git a/developer/tool/build_component/sync_engine.py b/developer/tool/build_component/sync_engine.py
new file mode 100644 (file)
index 0000000..cf6412b
--- /dev/null
+++ b/developer/tool/build_component/sync_engine.py
@@ -0,0 +1,80 @@
+#!/usr/bin/env -S python3 -B
+# -*- mode: python; coding: utf-8; python-indent-offset: 2; indent-tabs-mode: nil -*-
+# developer/tool/sync_engine.py
+
+import os
+import sys
+import shutil
+import filecmp
+import stat
+import tempfile
+
+def copy_file_atomic(src_abs, dst_abs, mode, dry=False, prefix="sync"):
+  if dry:
+    print(f"(dry) {prefix}: install -m {oct(mode)[2:]} '{src_abs}' -> '{dst_abs}'")
+    return
+
+  parent = os.path.dirname(dst_abs)
+  os.makedirs(parent, exist_ok=True)
+
+  fd, tmp_path = tempfile.mkstemp(prefix=".tmp.", dir=parent)
+  try:
+    with os.fdopen(fd, "wb") as tmpf, open(src_abs, "rb") as sf:
+      shutil.copyfileobj(sf, tmpf)
+      tmpf.flush()
+    os.chmod(tmp_path, mode)
+    os.replace(tmp_path, dst_abs)
+  except Exception as e:
+    if os.path.exists(tmp_path):
+      os.unlink(tmp_path)
+    raise e
+
+def execute_sync(src_root, dst_root, prefix="sync", dry=False, apply_modes=False, ignore_list=None):
+  wrote = False
+  if ignore_list is None:
+    ignore_list = []
+
+  if not os.path.isdir(src_root):
+    print(f"{prefix}: error: Source directory '{src_root}' does not exist.", file=sys.stderr)
+    return False
+
+  for root, dirs, files in os.walk(src_root):
+    dirs.sort()
+    files.sort()
+    for fn in files:
+      if fn in ignore_list:
+        continue
+      
+      src_abs = os.path.join(root, fn)
+      rel = os.path.relpath(src_abs, src_root)
+      dst_abs = os.path.join(dst_root, rel)
+
+      st = os.stat(src_abs)
+      if apply_modes:
+        is_exec = st.st_mode & stat.S_IXUSR
+        mode = 0o500 if is_exec else 0o400
+      else:
+        mode = stat.S_IMODE(st.st_mode)
+
+      if not os.path.exists(dst_abs):
+        copy_file_atomic(src_abs, dst_abs, mode, dry, prefix)
+        if not dry: print(f"{prefix}: Added   {rel}")
+        wrote = True
+        continue
+
+      if filecmp.cmp(src_abs, dst_abs, shallow=False):
+        continue
+
+      dst_st = os.stat(dst_abs)
+      if dst_st.st_mtime > st.st_mtime:
+        print(f"{prefix}: error: {rel} skipped. Destination version is newer.")
+        continue
+
+      copy_file_atomic(src_abs, dst_abs, mode, dry, prefix)
+      if not dry: print(f"{prefix}: Updated {rel}")
+      wrote = True
+
+  if not wrote and not dry:
+    print(f"{prefix}: (info) nothing new to synchronize from {src_root}")
+  
+  return wrote