diff_tree.py 文件源码

def walk_trees(store, tree1_id, tree2_id, prune_identical=False):
    """Recursively walk all the entries of two trees.

    Iteration is depth-first pre-order, as in e.g. os.walk.

    :param store: An ObjectStore for looking up objects.
    :param tree1_id: The SHA of the first Tree object to iterate, or None.
    :param tree2_id: The SHA of the second Tree object to iterate, or None.
    :param prune_identical: If True, identical subtrees will not be walked.
    :return: Iterator over Pairs of TreeEntry objects for each pair of entries
        in the trees and their subtrees recursively. If an entry exists in one
        tree but not the other, the other entry will have all attributes set
        to None. If neither entry's path is None, they are guaranteed to
        match.
    """
    # This could be fairly easily generalized to >2 trees if we find a use
    # case.
    mode1 = tree1_id and stat.S_IFDIR or None
    mode2 = tree2_id and stat.S_IFDIR or None
    todo = [(TreeEntry(b'', mode1, tree1_id), TreeEntry(b'', mode2, tree2_id))]
    while todo:
        entry1, entry2 = todo.pop()
        is_tree1 = _is_tree(entry1)
        is_tree2 = _is_tree(entry2)
        if prune_identical and is_tree1 and is_tree2 and entry1 == entry2:
            continue

        tree1 = is_tree1 and store[entry1.sha] or None
        tree2 = is_tree2 and store[entry2.sha] or None
        path = entry1.path or entry2.path
        todo.extend(reversed(_merge_entries(path, tree1, tree2)))
        yield entry1, entry2