| #!/usr/bin/env python3.8 |
| # Copyright 2020 The Fuchsia Authors. All rights reserved. |
| # # Use of this source code is governed by a BSD-style license that can be |
| # # found in the LICENSE file. |
| """Copy a directory into another one, completely replacing its previous content, if necessary.""" |
| |
| import argparse |
| import hashlib |
| import os |
| import pathlib |
| import shutil |
| import sys |
| |
| |
| def _compute_dir_hash(path): |
| """Compute a unique hash corresponding to the content of a given directory.""" |
| hasher = hashlib.md5() |
| for e in sorted(os.scandir(path), key=lambda x: x.name): |
| hasher.update(e.name.encode('utf-8') + b'\n') |
| if e.is_dir(follow_symlinks=False): |
| hasher.update(_compute_dir_hash(e.path)) |
| elif e.is_file(follow_symlinks=False): |
| with open(e.path, 'rb') as f: |
| hasher.update(f.read()) |
| elif e.is_symlink(): |
| hasher.update(os.readlink(e.path).encode('utf-8')) |
| else: |
| assert False, 'Not a file, directory or symlink: %s' % e.path |
| return hasher.digest() |
| |
| |
| def main(): |
| parser = argparse.ArgumentParser(description=__doc__) |
| parser.add_argument('--src', required=True, help='Source directory path.') |
| parser.add_argument( |
| '--dst', required=True, help='Destination directory path.') |
| |
| args = parser.parse_args() |
| |
| src_dir = args.src |
| assert os.path.exists(src_dir), 'Missing source directory: ' + src_dir |
| assert os.path.isdir(src_dir), 'Not a directory: ' + src_dir |
| |
| dst_dir = args.dst |
| if os.path.exists(dst_dir): |
| assert os.path.isdir(dst_dir), ( |
| 'Destination path exists but is not a directory: ' + dst_dir) |
| src_hash = _compute_dir_hash(src_dir) |
| dst_hash = _compute_dir_hash(dst_dir) |
| if dst_hash == src_hash: |
| # Don't do anything if both directories have the same content. |
| return 0 |
| |
| shutil.rmtree(dst_dir) |
| |
| shutil.copytree(src_dir, dst_dir, symlinks=True) |
| |
| # Ensure the destination directory is younger than any file it contains. |
| # This later prevent Ninja getting confused, and forcing rebuilds when |
| # none are needed :-( |
| pathlib.Path(dst_dir).touch() |
| return 0 |
| |
| |
| if __name__ == '__main__': |
| sys.exit(main()) |
