"""Module containing index utilities"""
from functools import wraps
import os
import struct
import tempfile
from types import TracebackType
from git.compat import is_win
import os.path as osp
# typing ----------------------------------------------------------------------
from typing import Any, Callable, TYPE_CHECKING, Optional, Type
from git.types import PathLike, _T
if TYPE_CHECKING:
from git.index import IndexFile
# ---------------------------------------------------------------------------------
__all__ = ("TemporaryFileSwap", "post_clear_cache", "default_index", "git_working_dir")
# { Aliases
pack = struct.pack
unpack = struct.unpack
# } END aliases
class TemporaryFileSwap(object):
"""Utility class moving a file to a temporary location within the same directory
and moving it back on to where on object deletion."""
__slots__ = ("file_path", "tmp_file_path")
def __init__(self, file_path: PathLike) -> None:
self.file_path = file_path
self.tmp_file_path = str(self.file_path) + tempfile.mktemp("", "", "")
# it may be that the source does not exist
try:
os.rename(self.file_path, self.tmp_file_path)
except OSError:
pass
def __enter__(self) -> "TemporaryFileSwap":
return self
def __exit__(
self,
exc_type: Optional[Type[BaseException]],
exc_val: Optional[BaseException],
exc_tb: Optional[TracebackType],
) -> bool:
if osp.isfile(self.tmp_file_path):
if is_win and osp.exists(self.file_path):
os.remove(self.file_path)
os.rename(self.tmp_file_path, self.file_path)
return False
# { Decorators
def post_clear_cache(func: Callable[..., _T]) -> Callable[..., _T]:
"""Decorator for functions that alter the index using the git command. This would
invalidate our possibly existing entries dictionary which is why it must be
deleted to allow it to be lazily reread later.
:note:
This decorator will not be required once all functions are implemented
natively which in fact is possible, but probably not feasible performance wise.
"""
@wraps(func)
def post_clear_cache_if_not_raised(self: "IndexFile", *args: Any, **kwargs: Any) -> _T:
rval = func(self, *args, **kwargs)
self._delete_entries_cache()
return rval
# END wrapper method
return post_clear_cache_if_not_raised
def default_index(func: Callable[..., _T]) -> Callable[..., _T]:
"""Decorator assuring the wrapped method may only run if we are the default
repository index. This is as we rely on git commands that operate
on that index only."""
@wraps(func)
def check_default_index(self: "IndexFile", *args: Any, **kwargs: Any) -> _T:
if self._file_path != self._index_path():
raise AssertionError(
"Cannot call %r on indices that do not represent the default git index" % func.__name__
)
return func(self, *args, **kwargs)
# END wrapper method
return check_default_index
def git_working_dir(func: Callable[..., _T]) -> Callable[..., _T]:
"""Decorator which changes the current working dir to the one of the git
repository in order to assure relative paths are handled correctly"""
@wraps(func)
def set_git_working_dir(self: "IndexFile", *args: Any, **kwargs: Any) -> _T:
cur_wd = os.getcwd()
os.chdir(str(self.repo.working_tree_dir))
try:
return func(self, *args, **kwargs)
finally:
os.chdir(cur_wd)
# END handle working dir
# END wrapper
return set_git_working_dir
# } END decorators
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