added make_archive (and secondary APIs) to shutil

Lib/shutil.py

@@ -9,9 +9,21 @@
 import stat
 from os.path import abspath
 import fnmatch
+from warnings import warn
+
+try:
+    from pwd import getpwnam
+except ImportError:
+    getpwnam = None
+
+try:
+    from grp import getgrnam
+except ImportError:
+    getgrnam = None
 
 __all__ = ["copyfileobj","copyfile","copymode","copystat","copy","copy2",
-           "copytree","move","rmtree","Error", "SpecialFileError"]
+           "copytree","move","rmtree","Error", "SpecialFileError",
+           "ExecError","make_archive"]
 
 class Error(EnvironmentError):
     pass
@@ -20,6 +32,9 @@ class SpecialFileError(EnvironmentError):
     """Raised when trying to do a kind of operation (e.g. copying) which is
     not supported on a special file (e.g. a named pipe)"""
 
+class ExecError(EnvironmentError):
+    """Raised when a command could not be executed"""
+
 try:
     WindowsError
 except NameError:
@@ -286,3 +301,267 @@ def _destinsrc(src, dst):
     if not dst.endswith(os.path.sep):
         dst += os.path.sep
     return dst.startswith(src)
+
+def _get_gid(name):
+    """Returns a gid, given a group name."""
+    if getgrnam is None or name is None:
+        return None
+    try:
+        result = getgrnam(name)
+    except KeyError:
+        result = None
+    if result is not None:
+        return result[2]
+    return None
+
+def _get_uid(name):
+    """Returns an uid, given a user name."""
+    if getpwnam is None or name is None:
+        return None
+    try:
+        result = getpwnam(name)
+    except KeyError:
+        result = None
+    if result is not None:
+        return result[2]
+    return None
+
+def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
+                  owner=None, group=None, logger=None):
+    """Create a (possibly compressed) tar file from all the files under
+    'base_dir'.
+
+    'compress' must be "gzip" (the default), "compress", "bzip2", or None.
+    (compress will be deprecated in Python 3.2)
+
+    'owner' and 'group' can be used to define an owner and a group for the
+    archive that is being built. If not provided, the current owner and group
+    will be used.
+
+    The output tar file will be named 'base_dir' +  ".tar", possibly plus
+    the appropriate compression extension (".gz", ".bz2" or ".Z").
+
+    Returns the output filename.
+    """
+    tar_compression = {'gzip': 'gz', 'bzip2': 'bz2', None: '', 'compress': ''}
+    compress_ext = {'gzip': '.gz', 'bzip2': '.bz2', 'compress': '.Z'}
+
+    # flags for compression program, each element of list will be an argument
+    if compress is not None and compress not in compress_ext.keys():
+        raise ValueError, \
+              ("bad value for 'compress': must be None, 'gzip', 'bzip2' "
+               "or 'compress'")
+
+    archive_name = base_name + '.tar'
+    if compress != 'compress':
+        archive_name += compress_ext.get(compress, '')
+
+    archive_dir = os.path.dirname(archive_name)
+    if not os.path.exists(archive_dir):
+        logger.info("creating %s" % archive_dir)
+        if not dry_run:
+            os.makedirs(archive_dir)
+
+
+    # creating the tarball
+    import tarfile  # late import so Python build itself doesn't break
+
+    if logger is not None:
+        logger.info('Creating tar archive')
+
+    uid = _get_uid(owner)
+    gid = _get_gid(group)
+
+    def _set_uid_gid(tarinfo):
+        if gid is not None:
+            tarinfo.gid = gid
+            tarinfo.gname = group
+        if uid is not None:
+            tarinfo.uid = uid
+            tarinfo.uname = owner
+        return tarinfo
+
+    if not dry_run:
+        tar = tarfile.open(archive_name, 'w|%s' % tar_compression[compress])
+        try:
+            tar.add(base_dir, filter=_set_uid_gid)
+        finally:
+            tar.close()
+
+    # compression using `compress`
+    # XXX this block will be removed in Python 3.2
+    if compress == 'compress':
+        warn("'compress' will be deprecated.", PendingDeprecationWarning)
+        # the option varies depending on the platform
+        compressed_name = archive_name + compress_ext[compress]
+        if sys.platform == 'win32':
+            cmd = [compress, archive_name, compressed_name]
+        else:
+            cmd = [compress, '-f', archive_name]
+        from distutils.spawn import spawn
+        spawn(cmd, dry_run=dry_run)
+        return compressed_name
+
+    return archive_name
+
+def _call_external_zip(directory, verbose=False):
+    # XXX see if we want to keep an external call here
+    if verbose:
+        zipoptions = "-r"
+    else:
+        zipoptions = "-rq"
+    from distutils.errors import DistutilsExecError
+    from distutils.spawn import spawn
+    try:
+        spawn(["zip", zipoptions, zip_filename, base_dir], dry_run=dry_run)
+    except DistutilsExecError:
+        # XXX really should distinguish between "couldn't find
+        # external 'zip' command" and "zip failed".
+        raise ExecError, \
+            ("unable to create zip file '%s': "
+            "could neither import the 'zipfile' module nor "
+            "find a standalone zip utility") % zip_filename
+
+def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
+    """Create a zip file from all the files under 'base_dir'.
+
+    The output zip file will be named 'base_dir' + ".zip".  Uses either the
+    "zipfile" Python module (if available) or the InfoZIP "zip" utility
+    (if installed and found on the default search path).  If neither tool is
+    available, raises ExecError.  Returns the name of the output zip
+    file.
+    """
+    zip_filename = base_name + ".zip"
+    archive_dir = os.path.dirname(base_name)
+
+    if not os.path.exists(archive_dir):
+        if logger is not None:
+            logger.info("creating %s", archive_dir)
+        if not dry_run:
+            os.makedirs(archive_dir)
+
+    # If zipfile module is not available, try spawning an external 'zip'
+    # command.
+    try:
+        import zipfile
+    except ImportError:
+        zipfile = None
+
+    if zipfile is None:
+        _call_external_zip(base_dir, verbose)
+    else:
+        if logger is not None:
+            logger.info("creating '%s' and adding '%s' to it",
+                        zip_filename, base_dir)
+
+        if not dry_run:
+            zip = zipfile.ZipFile(zip_filename, "w",
+                                  compression=zipfile.ZIP_DEFLATED)
+
+            for dirpath, dirnames, filenames in os.walk(base_dir):
+                for name in filenames:
+                    path = os.path.normpath(os.path.join(dirpath, name))
+                    if os.path.isfile(path):
+                        zip.write(path, path)
+                        if logger is not None:
+                            logger.info("adding '%s'", path)
+            zip.close()
+
+    return zip_filename
+
+_ARCHIVE_FORMATS = {
+    'gztar': (_make_tarball, [('compress', 'gzip')], "gzip'ed tar-file"),
+    'bztar': (_make_tarball, [('compress', 'bzip2')], "bzip2'ed tar-file"),
+    'ztar':  (_make_tarball, [('compress', 'compress')],
+                "compressed tar file"),
+    'tar':   (_make_tarball, [('compress', None)], "uncompressed tar file"),
+    'zip':   (_make_zipfile, [],"ZIP file")
+    }
+
+def get_archive_formats():
+    """Returns a list of supported formats for archiving and unarchiving.
+
+    Each element of the returned sequence is a tuple (name, description)
+    """
+    formats = [(name, registry[2]) for name, registry in
+               _ARCHIVE_FORMATS.items()]
+    formats.sort()
+    return formats
+
+def register_archive_format(name, function, extra_args=None, description=''):
+    """Registers an archive format.
+
+    name is the name of the format. function is the callable that will be
+    used to create archives. If provided, extra_args is a sequence of
+    (name, value) tuples that will be passed as arguments to the callable.
+    description can be provided to describe the format, and will be returned
+    by the get_archive_formats() function.
+    """
+    if extra_args is None:
+        extra_args = []
+    if not callable(function):
+        raise TypeError('The %s object is not callable' % function)
+    if not isinstance(extra_args, (tuple, list)):
+        raise TypeError('extra_args needs to be a sequence')
+    for element in extra_args:
+        if not isinstance(element, (tuple, list)) or len(element) !=2 :
+            raise TypeError('extra_args elements are : (arg_name, value)')
+
+    _ARCHIVE_FORMATS[name] = (function, extra_args, description)
+
+def unregister_archive_format(name):
+    del _ARCHIVE_FORMATS[name]
+
+def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
+                 dry_run=0, owner=None, group=None, logger=None):
+    """Create an archive file (eg. zip or tar).
+
+    'base_name' is the name of the file to create, minus any format-specific
+    extension; 'format' is the archive format: one of "zip", "tar", "ztar",
+    or "gztar".
+
+    'root_dir' is a directory that will be the root directory of the
+    archive; ie. we typically chdir into 'root_dir' before creating the
+    archive.  'base_dir' is the directory where we start archiving from;
+    ie. 'base_dir' will be the common prefix of all files and
+    directories in the archive.  'root_dir' and 'base_dir' both default
+    to the current directory.  Returns the name of the archive file.
+
+    'owner' and 'group' are used when creating a tar archive. By default,
+    uses the current owner and group.
+    """
+    save_cwd = os.getcwd()
+    if root_dir is not None:
+        if logger is not None:
+            logger.debug("changing into '%s'", root_dir)
+        base_name = os.path.abspath(base_name)
+        if not dry_run:
+            os.chdir(root_dir)
+
+    if base_dir is None:
+        base_dir = os.curdir
+
+    kwargs = {'dry_run': dry_run, 'logger': logger}
+
+    try:
+        format_info = _ARCHIVE_FORMATS[format]
+    except KeyError:
+        raise ValueError, "unknown archive format '%s'" % format
+
+    func = format_info[0]
+    for arg, val in format_info[1]:
+        kwargs[arg] = val
+
+    if format != 'zip':
+        kwargs['owner'] = owner
+        kwargs['group'] = group
+
+    try:
+        filename = func(base_name, base_dir, **kwargs)
+    finally:
+        if root_dir is not None:
+            if logger is not None:
+                logger.debug("changing back to '%s'", save_cwd)
+            os.chdir(save_cwd)
+
+    return filename