patchdir: move to libarchive-c

master
Taeyeon Mori 3 years ago
parent ee451645d4
commit 4dd0e8f947
  1. 309
      bin/patchdir

@ -1,24 +1,136 @@
#!/usr/bin/env python3
# Depends on 7z in path
# (c) 2017-2021 Taeyeon Mori
# Requires libarchive-c
#pylint: disable=missing-module-docstring,missing-function-docstring
import libarchive
import argparse
import pathlib
import contextlib
import os
import ctypes
import textwrap
import shlex
import libarchive
# Extend libarchive-c
from libarchive import ffi
try:
entry_copy_sourcepath = ffi.entry_copy_sourcepath
except AttributeError:
entry_copy_sourcepath = ffi.ffi("entry_copy_sourcepath",
[ffi.c_archive_entry_p, ffi.c_char_p],
None)
try:
read_disk_entry_from_file = ffi.read_disk_entry_from_file
except AttributeError:
read_disk_entry_from_file = ffi.ffi("read_disk_entry_from_file",
[ffi.c_archive_p, ffi.c_archive_entry_p, ffi.c_int, ffi.c_void_p],
ffi.c_int, ffi.check_int)
try:
write_set_format_filter_by_ext = ffi.write_set_format_filter_by_ext
except AttributeError:
write_set_format_filter_by_ext = ffi.ffi("write_set_format_filter_by_ext",
[ffi.c_archive_p, ffi.c_char_p],
ffi.c_int, ffi.check_int)
try:
read_extract = ffi.read_extract
except AttributeError:
read_extract = ffi.ffi("read_extract",
[ffi.c_archive_p, ffi.c_archive_entry_p, ffi.c_int],
ffi.c_int, ffi.check_int)
def to_bytes(path, encoding="utf-8"):
if encoding == "fsencode":
return os.fsencode(path)
if isinstance(path, os.PathLike):
path = os.fspath(path)
if isinstance(path, bytes):
return path
if isinstance(path, str):
return path.encode(encoding)
raise ValueError(f"Don't know how to convert {path} to bytes")
class _DiskRead(libarchive.read.ArchiveRead):
def add_file_to_archive(self, archive: libarchive.write.ArchiveWrite,
path: os.PathLike, archive_name: os.PathLike=None, *, bufsize=ffi.page_size*8):
archive_p = archive._pointer #pylint:disable=protected-access
with open(path, 'rb') as fp: #pylint:disable=invalid-name
with libarchive.entry.new_archive_entry() as entry_p:
if archive_name:
entry_copy_sourcepath(entry_p, to_bytes(path, "fsencode"))
ffi.entry_update_pathname_utf8(entry_p, to_bytes(archive_name, "utf-8"))
else:
ffi.entry_update_pathname_utf8(entry_p, to_bytes(path, "utf-8"))
read_disk_entry_from_file(self._pointer, entry_p, fp.fileno(), None)
ffi.write_header(archive_p, entry_p)
buf = bytearray(bufsize)
buf_ptr = ctypes.byref(ctypes.c_char.from_buffer(buf))
write_data = ffi.write_data
while (bytes_read := fp.readinto(buf)) > 0:
write_data(archive_p, buf_ptr, bytes_read)
ffi.write_finish_entry(archive_p)
@contextlib.contextmanager
def disk_reader(path=None, flags=0, lookup=True):
ard_p = ffi.read_disk_new()
try:
ffi.read_disk_set_behavior(ard_p, flags)
if lookup:
ffi.read_disk_set_standard_lookup(ard_p)
if path:
ffi.read_disk_open_w(ard_p, path)
yield _DiskRead(ard_p)
finally:
ffi.read_free(ard_p)
@contextlib.contextmanager
def file_writer_ext(filename):
archive_p = ffi.write_new()
try:
bfn = to_bytes(filename, "fsencode")
write_set_format_filter_by_ext(archive_p, bfn)
ffi.write_open_filename(archive_p, bfn)
try:
yield libarchive.write.ArchiveWrite(archive_p)
finally:
ffi.write_close(archive_p)
finally:
ffi.write_free(archive_p)
def extract_to_disk(entry: libarchive.entry.ArchiveEntry, path: os.PathLike=None):
archive_p, entry_p = entry._archive_p, entry._entry_p #pylint:disable=protected-access
if path:
ffi.entry_update_pathname_utf8(entry_p, to_bytes(path, "utf-8"))
read_extract(archive_p, entry_p,
libarchive.extract.EXTRACT_TIME|libarchive.extract.EXTRACT_UNLINK)
# Main
def parse_args(argv):
parser = argparse.ArgumentParser(prog=argv[0], description="""
Patch a folder structure with files from an archive.
This will replace existing files with those of the same name in an archive,
with the option to back up the old versions and generate a script to revert the changes.
""")
parser.add_argument("-p", "--strip", type=int, default=0, help="Strip NUM leading components from archived file names.")
parser.add_argument("-C", "--directory", default=".", help="Operate in <direcory>")
parser.add_argument("-b", "--backup", default=None, help="Create backup copies of overwritten files")
parser.add_argument("-m", "--match", default=None, help="Only extract files matching GLOB", metavar="GLOB")
parser.add_argument("-u", "--uninstall-script", default=os.devnull, help="Filename to save an uninstall-scipt to.", metavar="FILE")
parser.add_argument("-n", "--dry-run", action="store_true", help="Perform a dry run")
parser.add_argument("-p", "--strip", type=int, default=0,
help="Strip NUM leading components from archived file names.")
parser.add_argument("-C", "--directory", type=pathlib.Path, default=pathlib.Path("."),
help="Operate in <direcory>")
parser.add_argument("-b", "--backup", type=pathlib.Path, default=None,
help="Create backup copies of overwritten files")
parser.add_argument("-B", "--backup-archive", type=pathlib.Path, default=None,
help="Create an archive of the original files")
parser.add_argument("-m", "--match", default=None,
help="Only extract files matching GLOB", metavar="GLOB")
parser.add_argument("-u", "--uninstall-script", type=pathlib.Path, default=None,
help="Filename to save an uninstall-scipt to.", metavar="FILE")
parser.add_argument("-n", "--dry-run", action="store_true",
help="Perform a dry run")
parser.add_argument("archive", help="Achive file name")
return parser.parse_args(argv[1:])
@ -45,85 +157,138 @@ def makedirs(path, dryrun=False):
return created
def main(argv):
args = parse_args(argv)
output_path = pathlib.Path(args.directory)
backup_path = pathlib.Path(args.backup) if args.backup else None
folders = set()
with open(args.uninstall_script, "w") as us:
# Uninstall Header
if args.uninstall_script != os.devnull:
us.write("#!/bin/sh\n"
"# Automated patchdir uninstall script\n"
"# Run from inside patchdir's target directory (-C)\n"
"remove() {\n"
" echo Removing $1\n"
" rm \"$1\"\n"
"}\n\n")
if backup_path:
us.write(("BACKUP_PATH='%s'\n\n"
"restore() {\n"
" echo Restoring $1 from $BACKUP_PATH\n"
" mv \"$BACKUP_PATH/$1\" \"$1\"\n"
"}\n\n") % backup_path.relative_to(output_path))
with contextlib.ExitStack() as ctx:
# archive name is the only argument not affected by -C
archive = ctx.enter_context(libarchive.file_reader(args.archive))
# Change directory to target
os.chdir(args.directory)
if args.backup_archive and os.path.exists(args.backup_archive):
print("\033[31mError: Backup archive file already exist\033[0m")
return 3
uninstall_script = None
folders = set()
files = set()
if args.uninstall_script:
uninstall_script = ctx.enter_context(open(args.uninstall_script, "x"))
os.chmod(uninstall_script.fileno(), 0o755)
uninstall_script_dir = args.uninstall_script.parent.resolve()
uninstall_script.write(textwrap.dedent(f"""\
#!/bin/sh -eu
# Uninstall script generated by:
# {shlex.join(sys.argv)}
cd "`dirname "$0"`/{pathlib.Path.cwd().relative_to(uninstall_script_dir)}"
BACKUP_DIR={f"'{args.backup}'" if args.backup else ' # No backup directory was created (-b)'}
BACKUP_ARCHIVE={f"'{args.backup_archive}'" if args.backup_archive else ' # No backup archive was created (-B)'}
remove() {{
echo "Removing $1"
rm "$1"
}}
remove_dir() {{
rmdir "$1" || echo "\\033[34mFailed to remove folder $1\\033[0m"
}}
if [ -n "$BACKUP_DIR" -a -d "$BACKUP_DIR" ]; then
restore() {{
echo "Restoring $1 from $BACKUP_DIR"
mv "$BACKUP_DIR/$1" "$1"
}}
elif [ -n "$BACKUP_ARCHIVE" -a -f "$BACKUP_ARCHIVE" ]; then
restore() {{
echo "Restoring $1 from $BACKUP_ARCHIVE"
bsdtar -Uqxf "$BACKUP_ARCHIVE" "$1"
}}
elif [ -n "${{PATCHDIR_LOSE_FILES-}}" ]; then
restore() {{
echo "Removing $1 \\033[31m[Previously existing file is lost]\\033[0m"
rm "$1"
}}
elif ! grep -qE "restore\\s+[\\"'].+[\\"']" "$0"; then
: No files were overwritten
else
echo "\\033[31mError: Cannot restore original files because no backup is available\\033[0m"
echo "Set PATCHDIR_LOSE_FILES=1 to remove changed files without restoring originals"
exit 66
fi
# Restore Files #
"""))
backup_dir = None
backup_folders = set()
if args.backup:
backup_dir = args.backup
backup_archive = None
if args.backup_archive:
backup_archive = ctx.enter_context(file_writer_ext(args.backup_archive))
disk_rdr = ctx.enter_context(disk_reader())
for entry in archive:
epath = pathlib.Path(entry.path)
if args.match and not epath.match(args.match):
continue
if args.strip:
epath = pathlib.Path(*epath.parts[args.strip:])
if entry.isdir:
folders |= makedirs(epath, args.dry_run)
else:
us.write("remove-unsafe() {\n"
" echo Removing $1\n"
" rm \"$1\"\n"
" echo WARNING: Previously existing file $1 is now missing!\n"
"}\n\n")
us.write("\n# Restore files\n")
with libarchive.file_reader(args.archive) as archive:
for entry in archive:
epath = pathlib.PurePath(entry.path)
if args.match and not epath.match(args.match):
continue
if args.strip:
epath = pathlib.PurePath(*epath.parts[args.strip:])
dpath = output_path.joinpath(epath)
if entry.isdir:
folders |= makedirs(dpath, args.dry_run)
else:
folders |= makedirs(dpath.parent, args.dry_run)
folders |= makedirs(epath.parent, args.dry_run)
if dpath.exists():
# Archive might have multiple versions of the same file.
# Use the last one, but don't overwrite the backup with intermediate copies
if epath not in files:
files.add(epath)
if epath.exists():
# Backup
if backup_path:
print("Backing up existing %s" % epath)
bpath = backup_path.joinpath(epath)
folders |= makedirs(bpath.parent, args.dry_run)
if backup_archive:
print(f"Backing up {epath} to {args.backup_archive}")
disk_rdr.add_file_to_archive(backup_archive, epath)
if backup_dir:
print(f"Moving old {epath} to {args.backup}")
bpath = args.backup.joinpath(epath)
backup_folders |= makedirs(bpath.parent, args.dry_run)
if not args.dry_run:
os.rename(dpath, bpath)
os.rename(epath, bpath)
if uninstall_script:
uninstall_script.write(f"restore '{epath}'\n")
elif uninstall_script:
uninstall_script.write(f"remove '{epath}'\n")
print(f"Extracting {epath}")
if not args.dry_run:
extract_to_disk(entry, epath)
us.write("restore '%s'\n" % epath)
else:
us.write("remove-unsafe '%s'\n" % epath)
else:
us.write("remove '%s'\n" % epath)
if uninstall_script and (folders or backup_folders):
uninstall_script.write("\n# Remove folders #\n")
print("Extracting %s" % epath)
if backup_folders:
uninstall_script.write('if [ -n "$BACKUP_DIR" -a -d "$BACKUP_DIR" ]; then\n')
for dname in sorted(backup_folders, key=lambda x: len(x.parts), reverse=True):
uninstall_script.write(f"\tremove_dir '{dname}'\n")
uninstall_script.write('fi\n')
if not args.dry_run:
with open(dpath, "wb") as f:
for chunk in entry.get_blocks():
f.write(chunk)
if folders:
for dname in sorted(folders, key=lambda x: len(x.parts), reverse=True):
uninstall_script.write(f"remove_dir '{dname}'\n")
if args.uninstall_script != os.devnull and folders:
us.write("\n# Remove folders\n")
if uninstall_script:
uninstall_script.write(f"\n# Remove script #\nremove '{args.uninstall_script}'\n")
for dir in sorted(folders, key=lambda x: len(x.parts), reverse=True):
us.write("rmdir '%s'\n" % dir)
return 0
if __name__ == "__main__":
import sys
sys.exit(main(sys.argv))

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