Mini Shell
# Contains standalone functions to accompany the index implementation and make it
# more versatile
# NOTE: Autodoc hates it if this is a docstring
from io import BytesIO
from pathlib import Path
import os
from stat import (
S_IFDIR,
S_IFLNK,
S_ISLNK,
S_ISDIR,
S_IFMT,
S_IFREG,
S_IXUSR,
)
import subprocess
from git.cmd import PROC_CREATIONFLAGS, handle_process_output
from git.compat import (
defenc,
force_text,
force_bytes,
is_posix,
is_win,
safe_decode,
)
from git.exc import UnmergedEntriesError, HookExecutionError
from git.objects.fun import (
tree_to_stream,
traverse_tree_recursive,
traverse_trees_recursive,
)
from git.util import IndexFileSHA1Writer, finalize_process
from gitdb.base import IStream
from gitdb.typ import str_tree_type
import os.path as osp
from .typ import BaseIndexEntry, IndexEntry, CE_NAMEMASK, CE_STAGESHIFT
from .util import pack, unpack
# typing -----------------------------------------------------------------------------
from typing import Dict, IO, List, Sequence, TYPE_CHECKING, Tuple, Type, Union, cast
from git.types import PathLike
if TYPE_CHECKING:
from .base import IndexFile
from git.db import GitCmdObjectDB
from git.objects.tree import TreeCacheTup
# from git.objects.fun import EntryTupOrNone
# ------------------------------------------------------------------------------------
S_IFGITLINK = S_IFLNK | S_IFDIR # a submodule
CE_NAMEMASK_INV = ~CE_NAMEMASK
__all__ = (
"write_cache",
"read_cache",
"write_tree_from_cache",
"entry_key",
"stat_mode_to_index_mode",
"S_IFGITLINK",
"run_commit_hook",
"hook_path",
)
def hook_path(name: str, git_dir: PathLike) -> str:
""":return: path to the given named hook in the given git repository directory"""
return osp.join(git_dir, "hooks", name)
def _has_file_extension(path):
return osp.splitext(path)[1]
def run_commit_hook(name: str, index: "IndexFile", *args: str) -> None:
"""Run the commit hook of the given name. Silently ignores hooks that do not exist.
:param name: name of hook, like 'pre-commit'
:param index: IndexFile instance
:param args: arguments passed to hook file
:raises HookExecutionError:"""
hp = hook_path(name, index.repo.git_dir)
if not os.access(hp, os.X_OK):
return None
env = os.environ.copy()
env["GIT_INDEX_FILE"] = safe_decode(str(index.path))
env["GIT_EDITOR"] = ":"
cmd = [hp]
try:
if is_win and not _has_file_extension(hp):
# Windows only uses extensions to determine how to open files
# (doesn't understand shebangs). Try using bash to run the hook.
relative_hp = Path(hp).relative_to(index.repo.working_dir).as_posix()
cmd = ["bash.exe", relative_hp]
cmd = subprocess.Popen(
cmd + list(args),
env=env,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
cwd=index.repo.working_dir,
close_fds=is_posix,
creationflags=PROC_CREATIONFLAGS,
)
except Exception as ex:
raise HookExecutionError(hp, ex) from ex
else:
stdout_list: List[str] = []
stderr_list: List[str] = []
handle_process_output(cmd, stdout_list.append, stderr_list.append, finalize_process)
stdout = "".join(stdout_list)
stderr = "".join(stderr_list)
if cmd.returncode != 0:
stdout = force_text(stdout, defenc)
stderr = force_text(stderr, defenc)
raise HookExecutionError(hp, cmd.returncode, stderr, stdout)
# end handle return code
def stat_mode_to_index_mode(mode: int) -> int:
"""Convert the given mode from a stat call to the corresponding index mode
and return it"""
if S_ISLNK(mode): # symlinks
return S_IFLNK
if S_ISDIR(mode) or S_IFMT(mode) == S_IFGITLINK: # submodules
return S_IFGITLINK
return S_IFREG | (mode & S_IXUSR and 0o755 or 0o644) # blobs with or without executable bit
def write_cache(
entries: Sequence[Union[BaseIndexEntry, "IndexEntry"]],
stream: IO[bytes],
extension_data: Union[None, bytes] = None,
ShaStreamCls: Type[IndexFileSHA1Writer] = IndexFileSHA1Writer,
) -> None:
"""Write the cache represented by entries to a stream
:param entries: **sorted** list of entries
:param stream: stream to wrap into the AdapterStreamCls - it is used for
final output.
:param ShaStreamCls: Type to use when writing to the stream. It produces a sha
while writing to it, before the data is passed on to the wrapped stream
:param extension_data: any kind of data to write as a trailer, it must begin
a 4 byte identifier, followed by its size ( 4 bytes )"""
# wrap the stream into a compatible writer
stream_sha = ShaStreamCls(stream)
tell = stream_sha.tell
write = stream_sha.write
# header
version = 2
write(b"DIRC")
write(pack(">LL", version, len(entries)))
# body
for entry in entries:
beginoffset = tell()
write(entry.ctime_bytes) # ctime
write(entry.mtime_bytes) # mtime
path_str = str(entry.path)
path: bytes = force_bytes(path_str, encoding=defenc)
plen = len(path) & CE_NAMEMASK # path length
assert plen == len(path), "Path %s too long to fit into index" % entry.path
flags = plen | (entry.flags & CE_NAMEMASK_INV) # clear possible previous values
write(
pack(
">LLLLLL20sH",
entry.dev,
entry.inode,
entry.mode,
entry.uid,
entry.gid,
entry.size,
entry.binsha,
flags,
)
)
write(path)
real_size = (tell() - beginoffset + 8) & ~7
write(b"\0" * ((beginoffset + real_size) - tell()))
# END for each entry
# write previously cached extensions data
if extension_data is not None:
stream_sha.write(extension_data)
# write the sha over the content
stream_sha.write_sha()
def read_header(stream: IO[bytes]) -> Tuple[int, int]:
"""Return tuple(version_long, num_entries) from the given stream"""
type_id = stream.read(4)
if type_id != b"DIRC":
raise AssertionError("Invalid index file header: %r" % type_id)
unpacked = cast(Tuple[int, int], unpack(">LL", stream.read(4 * 2)))
version, num_entries = unpacked
# TODO: handle version 3: extended data, see read-cache.c
assert version in (1, 2)
return version, num_entries
def entry_key(*entry: Union[BaseIndexEntry, PathLike, int]) -> Tuple[PathLike, int]:
""":return: Key suitable to be used for the index.entries dictionary
:param entry: One instance of type BaseIndexEntry or the path and the stage"""
# def is_entry_key_tup(entry_key: Tuple) -> TypeGuard[Tuple[PathLike, int]]:
# return isinstance(entry_key, tuple) and len(entry_key) == 2
if len(entry) == 1:
entry_first = entry[0]
assert isinstance(entry_first, BaseIndexEntry)
return (entry_first.path, entry_first.stage)
else:
# assert is_entry_key_tup(entry)
entry = cast(Tuple[PathLike, int], entry)
return entry
# END handle entry
def read_cache(
stream: IO[bytes],
) -> Tuple[int, Dict[Tuple[PathLike, int], "IndexEntry"], bytes, bytes]:
"""Read a cache file from the given stream
:return: tuple(version, entries_dict, extension_data, content_sha)
* version is the integer version number
* entries dict is a dictionary which maps IndexEntry instances to a path at a stage
* extension_data is '' or 4 bytes of type + 4 bytes of size + size bytes
* content_sha is a 20 byte sha on all cache file contents"""
version, num_entries = read_header(stream)
count = 0
entries: Dict[Tuple[PathLike, int], "IndexEntry"] = {}
read = stream.read
tell = stream.tell
while count < num_entries:
beginoffset = tell()
ctime = unpack(">8s", read(8))[0]
mtime = unpack(">8s", read(8))[0]
(dev, ino, mode, uid, gid, size, sha, flags) = unpack(">LLLLLL20sH", read(20 + 4 * 6 + 2))
path_size = flags & CE_NAMEMASK
path = read(path_size).decode(defenc)
real_size = (tell() - beginoffset + 8) & ~7
read((beginoffset + real_size) - tell())
entry = IndexEntry((mode, sha, flags, path, ctime, mtime, dev, ino, uid, gid, size))
# entry_key would be the method to use, but we safe the effort
entries[(path, entry.stage)] = entry
count += 1
# END for each entry
# the footer contains extension data and a sha on the content so far
# Keep the extension footer,and verify we have a sha in the end
# Extension data format is:
# 4 bytes ID
# 4 bytes length of chunk
# repeated 0 - N times
extension_data = stream.read(~0)
assert (
len(extension_data) > 19
), "Index Footer was not at least a sha on content as it was only %i bytes in size" % len(extension_data)
content_sha = extension_data[-20:]
# truncate the sha in the end as we will dynamically create it anyway
extension_data = extension_data[:-20]
return (version, entries, extension_data, content_sha)
def write_tree_from_cache(
entries: List[IndexEntry], odb: "GitCmdObjectDB", sl: slice, si: int = 0
) -> Tuple[bytes, List["TreeCacheTup"]]:
"""Create a tree from the given sorted list of entries and put the respective
trees into the given object database
:param entries: **sorted** list of IndexEntries
:param odb: object database to store the trees in
:param si: start index at which we should start creating subtrees
:param sl: slice indicating the range we should process on the entries list
:return: tuple(binsha, list(tree_entry, ...)) a tuple of a sha and a list of
tree entries being a tuple of hexsha, mode, name"""
tree_items: List["TreeCacheTup"] = []
ci = sl.start
end = sl.stop
while ci < end:
entry = entries[ci]
if entry.stage != 0:
raise UnmergedEntriesError(entry)
# END abort on unmerged
ci += 1
rbound = entry.path.find("/", si)
if rbound == -1:
# its not a tree
tree_items.append((entry.binsha, entry.mode, entry.path[si:]))
else:
# find common base range
base = entry.path[si:rbound]
xi = ci
while xi < end:
oentry = entries[xi]
orbound = oentry.path.find("/", si)
if orbound == -1 or oentry.path[si:orbound] != base:
break
# END abort on base mismatch
xi += 1
# END find common base
# enter recursion
# ci - 1 as we want to count our current item as well
sha, _tree_entry_list = write_tree_from_cache(entries, odb, slice(ci - 1, xi), rbound + 1)
tree_items.append((sha, S_IFDIR, base))
# skip ahead
ci = xi
# END handle bounds
# END for each entry
# finally create the tree
sio = BytesIO()
tree_to_stream(tree_items, sio.write) # writes to stream as bytes, but doesn't change tree_items
sio.seek(0)
istream = odb.store(IStream(str_tree_type, len(sio.getvalue()), sio))
return (istream.binsha, tree_items)
def _tree_entry_to_baseindexentry(tree_entry: "TreeCacheTup", stage: int) -> BaseIndexEntry:
return BaseIndexEntry((tree_entry[1], tree_entry[0], stage << CE_STAGESHIFT, tree_entry[2]))
def aggressive_tree_merge(odb: "GitCmdObjectDB", tree_shas: Sequence[bytes]) -> List[BaseIndexEntry]:
"""
:return: list of BaseIndexEntries representing the aggressive merge of the given
trees. All valid entries are on stage 0, whereas the conflicting ones are left
on stage 1, 2 or 3, whereas stage 1 corresponds to the common ancestor tree,
2 to our tree and 3 to 'their' tree.
:param tree_shas: 1, 2 or 3 trees as identified by their binary 20 byte shas
If 1 or two, the entries will effectively correspond to the last given tree
If 3 are given, a 3 way merge is performed"""
out: List[BaseIndexEntry] = []
# one and two way is the same for us, as we don't have to handle an existing
# index, instrea
if len(tree_shas) in (1, 2):
for entry in traverse_tree_recursive(odb, tree_shas[-1], ""):
out.append(_tree_entry_to_baseindexentry(entry, 0))
# END for each entry
return out
# END handle single tree
if len(tree_shas) > 3:
raise ValueError("Cannot handle %i trees at once" % len(tree_shas))
# three trees
for base, ours, theirs in traverse_trees_recursive(odb, tree_shas, ""):
if base is not None:
# base version exists
if ours is not None:
# ours exists
if theirs is not None:
# it exists in all branches, if it was changed in both
# its a conflict, otherwise we take the changed version
# This should be the most common branch, so it comes first
if (base[0] != ours[0] and base[0] != theirs[0] and ours[0] != theirs[0]) or (
base[1] != ours[1] and base[1] != theirs[1] and ours[1] != theirs[1]
):
# changed by both
out.append(_tree_entry_to_baseindexentry(base, 1))
out.append(_tree_entry_to_baseindexentry(ours, 2))
out.append(_tree_entry_to_baseindexentry(theirs, 3))
elif base[0] != ours[0] or base[1] != ours[1]:
# only we changed it
out.append(_tree_entry_to_baseindexentry(ours, 0))
else:
# either nobody changed it, or they did. In either
# case, use theirs
out.append(_tree_entry_to_baseindexentry(theirs, 0))
# END handle modification
else:
if ours[0] != base[0] or ours[1] != base[1]:
# they deleted it, we changed it, conflict
out.append(_tree_entry_to_baseindexentry(base, 1))
out.append(_tree_entry_to_baseindexentry(ours, 2))
# else:
# we didn't change it, ignore
# pass
# END handle our change
# END handle theirs
else:
if theirs is None:
# deleted in both, its fine - its out
pass
else:
if theirs[0] != base[0] or theirs[1] != base[1]:
# deleted in ours, changed theirs, conflict
out.append(_tree_entry_to_baseindexentry(base, 1))
out.append(_tree_entry_to_baseindexentry(theirs, 3))
# END theirs changed
# else:
# theirs didn't change
# pass
# END handle theirs
# END handle ours
else:
# all three can't be None
if ours is None:
# added in their branch
assert theirs is not None
out.append(_tree_entry_to_baseindexentry(theirs, 0))
elif theirs is None:
# added in our branch
out.append(_tree_entry_to_baseindexentry(ours, 0))
else:
# both have it, except for the base, see whether it changed
if ours[0] != theirs[0] or ours[1] != theirs[1]:
out.append(_tree_entry_to_baseindexentry(ours, 2))
out.append(_tree_entry_to_baseindexentry(theirs, 3))
else:
# it was added the same in both
out.append(_tree_entry_to_baseindexentry(ours, 0))
# END handle two items
# END handle heads
# END handle base exists
# END for each entries tuple
return out
Zerion Mini Shell 1.0