hgext/git/gitutil.py
author Pierre-Yves David <pierre-yves.david@octobus.net>
Fri, 15 Mar 2024 01:31:57 +0100
branchstable
changeset 51505 c9ceb4f60256
parent 49849 de9ffb82ef4d
permissions -rw-r--r--
phases: avoid N² behavior in `advanceboundary` We allowed duplicated entries in the deque, which each entry could potentially insert all its ancestors. So advancing boundary for the full repository would mean each revision would walk all its ancestors, resulting in O(N²) iteration. For repository of any decent size, N² is quickly insane. We introduce a simple set to avoid this and get back to reasonable performance.

"""utilities to assist in working with pygit2"""

from mercurial.node import bin, sha1nodeconstants

pygit2_module = None


def get_pygit2():
    global pygit2_module
    if pygit2_module is None:
        try:
            import pygit2 as pygit2_module  # pytype: disable=import-error

            pygit2_module.InvalidSpecError
        except (ImportError, AttributeError):
            pass
    return pygit2_module


def pygit2_version():
    mod = get_pygit2()
    v = "N/A"

    if mod:
        try:
            v = mod.__version__
        except AttributeError:
            pass

    return b"(pygit2 %s)" % v.encode("utf-8")


def togitnode(n):
    """Wrapper to convert a Mercurial binary node to a unicode hexlified node.

    pygit2 and sqlite both need nodes as strings, not bytes.
    """
    assert len(n) == 20
    return n.hex()


def fromgitnode(n):
    """Opposite of togitnode."""
    assert len(n) == 40
    return bin(n)


nullgit = togitnode(sha1nodeconstants.nullid)