diff_tree.py 文件源码

def _find_content_rename_candidates(self):
        candidates = self._candidates = []
        # TODO: Optimizations:
        #  - Compare object sizes before counting blocks.
        #  - Skip if delete's S_IFMT differs from all adds.
        #  - Skip if adds or deletes is empty.
        # Match C git's behavior of not attempting to find content renames if
        # the matrix size exceeds the threshold.
        if not self._should_find_content_renames():
            return

        block_cache = {}
        check_paths = self._rename_threshold is not None
        for delete in self._deletes:
            if S_ISGITLINK(delete.old.mode):
                continue  # Git links don't exist in this repo.
            old_sha = delete.old.sha
            old_obj = self._store[old_sha]
            block_cache[old_sha] = _count_blocks(old_obj)
            for add in self._adds:
                if stat.S_IFMT(delete.old.mode) != stat.S_IFMT(add.new.mode):
                    continue
                new_obj = self._store[add.new.sha]
                score = _similarity_score(old_obj, new_obj,
                                          block_cache=block_cache)
                if score > self._rename_threshold:
                    new_type = self._rename_type(check_paths, delete, add)
                    rename = TreeChange(new_type, delete.old, add.new)
                    candidates.append((-score, rename))