delta-find: use a single snapshot cache when applying a group to an object
This will avoid walking the revlog over and over again in some situations.
The difference is hard to show in our current benchmark suite, as the gain is
lower than their overall instability.
"""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
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)