diff --git a/pristine_zip/main.py b/pristine_zip/main.py index cc65e67..bc7b486 100644 --- a/pristine_zip/main.py +++ b/pristine_zip/main.py @@ -1,127 +1,141 @@ # Copyright (C) 2020 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import functools import os.path import tempfile import click from . import common from . import delta_to_zipball from . import parameters from . import reference from . import zipball_to_delta def print_pristinezip_exceptions(f): """Decorator for CLI functions to display PristineZipException exception nicely instead of showing a traceback.""" @functools.wraps(f) def newf(*args, **kwargs): try: return f(*args, **kwargs) except common.PristineZipException as e: raise click.ClickException(*e.args) return newf @click.group() @click.option( "--infozip30", default="zip", type=str, help=( "Path to an InfoZip 3.0 executable (usually the default 'zip' on " "Unix-like distributions)." ), ) @click.option( "--7zip63", "sevenzip63", default="7z", type=str, - help=("Path to a 7zip executable. Usually '7z'."), + help="Path to a 7zip executable. Usually '7z'.", +) +@click.option( + "--strict-guess/--lax-guess", + default=True, + help=( + "Whether pristine-zip should try guess the encoding software even when " + "it has no idea what it is." + ), ) @click.pass_context -def cli(ctx, infozip30, sevenzip63): +def cli(ctx, infozip30, sevenzip63, strict_guess): ctx.ensure_object(dict) + ctx.obj["strict_guess"] = strict_guess ctx.obj["executables"] = common.Executables( infozip_3_0=infozip30, sevenzip_6_3=sevenzip63, ) @cli.command() @click.argument("zipball", type=click.Path(exists=True, readable=True)) @click.argument("delta", type=click.Path()) @click.pass_context @print_pristinezip_exceptions def gendelta(ctx, zipball: str, delta: str): """Takes an upstream zipball and generates a small binary delta that can be used to re-generate the zipball.""" zipball_to_delta.gendelta( - ctx.obj["executables"], os.path.abspath(zipball), os.path.abspath(delta) + ctx.obj["executables"], + os.path.abspath(zipball), + os.path.abspath(delta), + strict_guess=ctx.obj["strict_guess"], ) @cli.command() @click.argument("delta", type=click.Path(exists=True, readable=True)) @click.argument("zipball", type=click.Path()) @click.pass_context @print_pristinezip_exceptions def genzip(ctx, delta: str, zipball: str): """Takes a delta generated by 'pristine-zip gendelta' and reads files from the CWD to generate the exact same zipball as was given to 'gendelta'.""" checkout_dir = os.getcwd() delta_to_zipball.genzip( ctx.obj["executables"], checkout_dir, os.path.abspath(delta), os.path.abspath(zipball), ) @cli.command() @click.argument("source_zipball", type=click.Path(exists=True, readable=True)) @click.argument("reference_zipball", type=click.Path()) @click.pass_context @print_pristinezip_exceptions def regenzip(ctx, source_zipball: str, reference_zipball: str): """Takes a zipball and generates a reference zipball from it.""" with tempfile.TemporaryDirectory() as work_dir: - encoding_software = parameters.guess_encoding_software(source_zipball) + encoding_software = parameters.guess_encoding_software( + source_zipball, strict_guess=ctx.obj["strict_guess"], + ) zipball_to_delta.generate_reference_zipball_from_zipball( ctx.obj["executables"], encoding_software, os.path.abspath(source_zipball), os.path.abspath(reference_zipball), work_dir, ) @cli.command() @click.argument("reference_zipball", type=click.Path()) @click.argument( "encoding_software", type=click.Choice([es.value for es in parameters.EncodingSoftware]), ) @click.pass_context @print_pristinezip_exceptions def cwdgenzip(ctx, reference_zipball: str, encoding_software): """Reads the CWD and generates a reference zipball from it.""" checkout_dir = os.getcwd() reference.compress( ctx.obj["executables"], parameters.EncodingSoftware(encoding_software), checkout_dir, reference_zipball, ) def main(): return cli() diff --git a/pristine_zip/reference.py b/pristine_zip/reference.py index 12352f2..366757f 100644 --- a/pristine_zip/reference.py +++ b/pristine_zip/reference.py @@ -1,90 +1,92 @@ # Copyright (C) 2020 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information """Creates a ZIP file deterministically. This can be used a base reference for delta files.""" import os import subprocess from . import common from . import parameters def normalize_timestamps(entries): for entry in entries: os.utime(entry, (0, 0)) def normalize_perms(checkout_dir): # Info-ZIP has an extension that allows storing permissions; but not all # implementations support it (eg. not Python). So let's normalize by # wiping all permissions. for dir_entry in os.scandir(checkout_dir): if dir_entry.is_dir(follow_symlinks=False): os.chmod(dir_entry.path, 0o100755) normalize_perms(dir_entry.path) elif dir_entry.is_file(follow_symlinks=False): os.chmod(dir_entry.path, 0o100644) elif dir_entry.is_symlink(): os.chmod(dir_entry.path, 0o120000) else: assert False, f"Unknown DirEntry type: {dir_entry}" def walk(checkout_dir): entries = [] for (dirpath, dirnames, filenames) in os.walk(checkout_dir): assert dirpath.startswith(checkout_dir) dirpath = dirpath[len(checkout_dir) :].lstrip("/") entries.append(dirpath) paths = [os.path.join(dirpath, filename) for filename in filenames] entries.extend(paths) return entries def compress( executables: common.Executables, encoding_software: parameters.EncodingSoftware, checkout_dir: str, target: str, ): """Generates a reference zipball for the given checked out directory.""" try: os.remove(target) except FileNotFoundError: pass assert os.path.isdir(checkout_dir), checkout_dir entries_str = walk(checkout_dir) normalize_perms(checkout_dir) normalize_timestamps(os.path.join(checkout_dir, entry) for entry in entries_str) # Encode *before* sorting; sorting on unicode changes across configurations. entries = [entry.encode() for entry in entries_str] # Sort entries ourselves; InfoZIP's zip does not guarantee order entries.sort() if encoding_software == parameters.EncodingSoftware.INFOZIP_3_0: # -X = --no-extra, which prevents inclusion of extra non-deterministic # and implementation-dependant data # -o = --latest-time, which sets the modification time of the zip to that # of the most recent file assert executables.infozip_3_0 proc = subprocess.run( [executables.infozip_3_0, "-X", "-o", target, "--names-stdin"], cwd=checkout_dir, input=b"\n".join(entries), ) proc.check_returncode() elif encoding_software == parameters.EncodingSoftware.SEVENZIP_6_3: assert executables.sevenzip_6_3 assert target.endswith(".zip") proc = subprocess.run( - [executables.sevenzip_6_3, "a", target, *entries], cwd=checkout_dir, + [executables.sevenzip_6_3, "a", target, *entries], + cwd=checkout_dir, + capture_output=True, ) proc.check_returncode() diff --git a/pristine_zip/zipball_to_delta.py b/pristine_zip/zipball_to_delta.py index 016d2fe..407f065 100644 --- a/pristine_zip/zipball_to_delta.py +++ b/pristine_zip/zipball_to_delta.py @@ -1,123 +1,131 @@ # Copyright (C) 2020 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information import os import subprocess import tempfile from . import common from . import parameters from . import reference -def gendelta(executables: common.Executables, zipball_path: str, delta_path: str): - encoding_software = parameters.guess_encoding_software(zipball_path) +def gendelta( + executables: common.Executables, + zipball_path: str, + delta_path: str, + *, + strict_guess: bool, +): + encoding_software = parameters.guess_encoding_software( + zipball_path, strict_guess=strict_guess + ) with tempfile.TemporaryDirectory(prefix="pristine-zip-gendelta") as work_dir: reference_zipball_path = os.path.join(work_dir, "reference.zip") generate_reference_zipball_from_zipball( executables, encoding_software, zipball_path, reference_zipball_path, work_dir, ) _generate_delta( executables, encoding_software, zipball_path, reference_zipball_path, work_dir, delta_path, ) def _generate_delta( executables: common.Executables, encoding_software: parameters.EncodingSoftware, upstream_zipball_path: str, reference_zipball_path: str, work_dir: str, delta_path: str, ): _generate_xdelta3( upstream_zipball_path, reference_zipball_path, os.path.join(work_dir, "delta") ) with open(os.path.join(work_dir, "type"), "wb") as fd: fd.write(b"zip\n") proc = subprocess.run(["md5sum", reference_zipball_path], capture_output=True) proc.check_returncode() md5sum = proc.stdout.split(b" ", 1)[0] with open(os.path.join(work_dir, "reference_md5sum"), "wb") as fd: fd.write(md5sum + b"\n") with open(os.path.join(work_dir, "encoding_software"), "wb") as fd: fd.write(encoding_software.value.encode() + b"\n") files = ["delta", "encoding_software", "reference_md5sum", "type"] # Make the timestamps in the delta tarball deterministic for file in files: os.utime(os.path.join(work_dir, file), times=(0, 0)) proc = subprocess.run( [ "tar", # make entries in the delta tarball deterministic: "--owner", "0", "--group", "0", "--numeric-owner", "--mode", "644", # generic options: "--create", "--gzip", "-f", delta_path, *files, ], cwd=work_dir, ) proc.check_returncode() def _generate_xdelta3( upstream_zipball_path: str, reference_zipball_path: str, delta_path: str ): """Generates the xdelta3 difference between a reference zipball and the original one.""" proc = subprocess.run( [ "xdelta3", "-e", "-s", reference_zipball_path, upstream_zipball_path, delta_path, ] ) proc.check_returncode() def generate_reference_zipball_from_zipball( executables: common.Executables, encoding_software: parameters.EncodingSoftware, upstream_zipball_path: str, reference_zipball_path: str, work_dir: str, ): """Unzips an upstream zipball and rezips it in a reference zipball.""" checkout_dir = os.path.join(work_dir, "checkout") os.mkdir(checkout_dir) proc = subprocess.run(["unzip", upstream_zipball_path], cwd=checkout_dir) proc.check_returncode() reference.compress( executables, encoding_software, checkout_dir, reference_zipball_path )