org_fedora_oscap.cpioarchive.CpioArchive.__next__() - Code Metrics - Inspection of "Merge the cpio module into the addon." - OpenSCAP/oscap-anaconda-addon - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#140)

by Matěj

created 2021-03-11 16:19 UTC

CpioArchive.next() A

↳ Parent: org_fedora_oscap.cpioarchive

Complexity

Conditions

Size

Total Lines	2
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	2
dl	0
loc	2
rs	10
c	0
b	0
f	0
cc	1
nop	1

from __future__ import absolute_import

import atexit

""" cpioarchive: Support for cpio archives
Copyright (C) 2006 Ignacio Vazquez-Abrams """

""" This library is free software; you can redistribute it and/or modify it under the terms of the
GNU Lesser General Public License as published by the Free Software Foundation;
either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library;
if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""


def version():
    """Returns the version number of the module."""
    return '0.1'


class CpioError(Exception):
    """Exception class for cpioarchive exceptions"""
    pass


class CpioEntry(object):
    """Information about a single file in a cpio archive.
    Provides a file-like interface for interacting with the entry."""
    def __init__(self, hdr, cpio, offset):
        """Create a new CpioEntry instance. Internal use only."""
        if len(hdr) < 110:
            raise CpioError('cpio header too short')
        if not hdr.startswith(b'070701'):
            raise CpioError('cpio header invalid')
        self.inode = int(hdr[6:14], 16)
        self.mode = int(hdr[14:22], 16)
        self.uid = int(hdr[22:30], 16)
        self.gid = int(hdr[30:38], 16)
        self.nlinks = int(hdr[38:46], 16)
        self.mtime = int(hdr[46:54], 16)
        self.size = int(hdr[54:62], 16)
        """Size of the file stored in the entry."""
        self.devmajor = int(hdr[62:70], 16)
        self.devminor = int(hdr[70:78], 16)
        self.rdevmajor = int(hdr[78:86], 16)
        self.rdevminor = int(hdr[86:94], 16)
        namesize = int(hdr[94:102], 16)
        self.checksum = int(hdr[102:110], 16)
        if len(hdr) < 110+namesize:
            raise CpioError('cpio header too short')
        self.name = hdr[110:110+namesize-1].decode("utf-8")
        """Name of the file stored in the entry."""
        self.datastart = offset+110+namesize
        self.datastart += (4-(self.datastart % 4)) % 4
        self.curoffset = 0
        self.cpio = cpio
        self.closed = False

    def close(self):
        """Close this cpio entry. Further calls to methods will raise an exception."""
        self.closed = True

    def flush(self):
        """Flush the entry (no-op)."""
        pass

    def read(self, size=None):
        """Read data from the entry.

        Args:
            size -- Number of bytes to read (default: whole entry)
        """
        if self.closed:
            raise ValueError('read operation on closed file')
        self.cpio.file.seek(self.datastart+self.curoffset, 0)
        if size and size < self.size-self.curoffset:
            ret = self.cpio.file.read(size)
        else:
            ret = self.cpio.file.read(self.size-self.curoffset)
        self.curoffset += len(ret)
        return ret

    def seek(self, offset, whence=0):
        """Move to new position within an entry.

        Args:
            offset -- Byte count
            whence -- Describes how offset is used.
                0: From beginning of file
                1: Forwards from current position
                2: Backwards from current position
                Other values are ignored.
        """
        if self.closed:
            raise ValueError('seek operation on closed file')
        if whence == 0:
            self.curoffset = offset
        elif whence == 1:
            self.curoffset += offset
        elif whence == 2:
            self.curoffset -= offset
        self.curoffset = min(max(0, self.curoffset), self.size)

    def tell(self):
        """Get current position within an entry"""
        if self.closed:
            raise ValueError('tell operation on closed file')
        return self.curoffset


class CpioArchive(object):
    @classmethod
    def open(name=None, mode='r', fileobj=None):
        """Open a cpio archive. Defers to CpioArchive.__init__()."""
        return CpioArchive(name, mode, fileobj)

    def __init__(self, name=None, mode='r', fileobj=None):
        """Open a cpio archive.

        Args:
            name -- Filename to open (default: open a file object instead)
            mode -- Filemode to open the archive in (default: read-only)
            fileobj -- File object to use (default: open by filename instead)
        """
        if not mode == 'r':
            raise NotImplementedError()
        self._infos = []
        if name:
            self._readfile(name)
            self.external = False
        elif fileobj:
            self._readobj(fileobj)
            self.external = True
        else:
            raise CpioError('Oh come on! Pass me something to work with...')
        self._ptr = 0
        self.closed = False
        atexit.register(self.close)

    def close(self):
        """Close the CpioArchive. Also closes all associated entries."""
        if self.closed:
            return
        [x.close() for x in self._infos]
        self.closed = True
        if not self.external:
            self.file.close()

    def __next__(self):
        return self.next()

    def next(self):
        """Return the next entry in the archive."""
        if self.closed:
            raise ValueError('next operation on closed file')
        if self._ptr > len(self._infos):
            raise StopIteration()
        ret = self._infos[self._ptr]
        self._ptr += 1
        return ret

    def __iter__(self):
        return iter(self._infos)

    def _readfile(self, name):
        self._readobj(open(name, 'rb'))

    def _readobj(self, fileobj):
        self.file = fileobj
        start = self.file.tell()
        istart = self.file.tell()
        text = self.file.read(110)
        while text:
            namelen = int(text[94:102], 16)
            text += self.file.read(namelen)
            ce = CpioEntry(text, self, istart)
            if not ce.name == "TRAILER!!!":
                self._infos.append(ce)
            else:
                return
            self.file.seek((4-(self.file.tell()-istart) % 4) % 4, 1)
            self.file.seek(self._infos[-1].size, 1)
            self.file.seek((4-(self.file.tell()-istart) % 4) % 4, 1)

            istart = self.file.tell()
            text = self.file.read(110)
        else:
            raise CpioError('premature end of headers')


1			from __future__ import absolute_import
2
3			import atexit
4
5			""" cpioarchive: Support for cpio archives
6			Copyright (C) 2006 Ignacio Vazquez-Abrams """
7
8			""" This library is free software; you can redistribute it and/or modify it under the terms of the
9			GNU Lesser General Public License as published by the Free Software Foundation;
10			either version 2.1 of the License, or (at your option) any later version.
11
12			This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
13			without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
14			See the GNU Lesser General Public License for more details.
15
16			You should have received a copy of the GNU Lesser General Public License along with this library;
17			if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18			"""
19
20
21			def version():
22			"""Returns the version number of the module."""
23			return '0.1'
24
25
26			class CpioError(Exception):
27			"""Exception class for cpioarchive exceptions"""
28			pass
29
30
31			class CpioEntry(object):
32			"""Information about a single file in a cpio archive.
33			Provides a file-like interface for interacting with the entry."""
34			def __init__(self, hdr, cpio, offset):
35			"""Create a new CpioEntry instance. Internal use only."""
36			if len(hdr) < 110:
37			raise CpioError('cpio header too short')
38			if not hdr.startswith(b'070701'):
39			raise CpioError('cpio header invalid')
40			self.inode = int(hdr[6:14], 16)
41			self.mode = int(hdr[14:22], 16)
42			self.uid = int(hdr[22:30], 16)
43			self.gid = int(hdr[30:38], 16)
44			self.nlinks = int(hdr[38:46], 16)
45			self.mtime = int(hdr[46:54], 16)
46			self.size = int(hdr[54:62], 16)
47			"""Size of the file stored in the entry."""
48			self.devmajor = int(hdr[62:70], 16)
49			self.devminor = int(hdr[70:78], 16)
50			self.rdevmajor = int(hdr[78:86], 16)
51			self.rdevminor = int(hdr[86:94], 16)
52			namesize = int(hdr[94:102], 16)
53			self.checksum = int(hdr[102:110], 16)
54			if len(hdr) < 110+namesize:
55			raise CpioError('cpio header too short')
56			self.name = hdr[110:110+namesize-1].decode("utf-8")
57			"""Name of the file stored in the entry."""
58			self.datastart = offset+110+namesize
59			self.datastart += (4-(self.datastart % 4)) % 4
60			self.curoffset = 0
61			self.cpio = cpio
62			self.closed = False
63
64			def close(self):
65			"""Close this cpio entry. Further calls to methods will raise an exception."""
66			self.closed = True
67
68			def flush(self):
69			"""Flush the entry (no-op)."""
70			pass
71
72			def read(self, size=None):
73			"""Read data from the entry.
74
75			Args:
76			size -- Number of bytes to read (default: whole entry)
77			"""
78			if self.closed:
79			raise ValueError('read operation on closed file')
80			self.cpio.file.seek(self.datastart+self.curoffset, 0)
81			if size and size < self.size-self.curoffset:
82			ret = self.cpio.file.read(size)
83			else:
84			ret = self.cpio.file.read(self.size-self.curoffset)
85			self.curoffset += len(ret)
86			return ret
87
88			def seek(self, offset, whence=0):
89			"""Move to new position within an entry.
90
91			Args:
92			offset -- Byte count
93			whence -- Describes how offset is used.
94			0: From beginning of file
95			1: Forwards from current position
96			2: Backwards from current position
97			Other values are ignored.
98			"""
99			if self.closed:
100			raise ValueError('seek operation on closed file')
101			if whence == 0:
102			self.curoffset = offset
103			elif whence == 1:
104			self.curoffset += offset
105			elif whence == 2:
106			self.curoffset -= offset
107			self.curoffset = min(max(0, self.curoffset), self.size)
108
109			def tell(self):
110			"""Get current position within an entry"""
111			if self.closed:
112			raise ValueError('tell operation on closed file')
113			return self.curoffset
114
115
116			class CpioArchive(object):
117			@classmethod
118			def open(name=None, mode='r', fileobj=None):
119			"""Open a cpio archive. Defers to CpioArchive.__init__()."""
120			return CpioArchive(name, mode, fileobj)
121
122			def __init__(self, name=None, mode='r', fileobj=None):
123			"""Open a cpio archive.
124
125			Args:
126			name -- Filename to open (default: open a file object instead)
127			mode -- Filemode to open the archive in (default: read-only)
128			fileobj -- File object to use (default: open by filename instead)
129			"""
130			if not mode == 'r':
131			raise NotImplementedError()
132			self._infos = []
133			if name:
134			self._readfile(name)
135			self.external = False
136			elif fileobj:
137			self._readobj(fileobj)
138			self.external = True
139			else:
140			raise CpioError('Oh come on! Pass me something to work with...')
141			self._ptr = 0
142			self.closed = False
143			atexit.register(self.close)
144
145			def close(self):
146			"""Close the CpioArchive. Also closes all associated entries."""
147			if self.closed:
148			return
149			[x.close() for x in self._infos]
150			self.closed = True
151			if not self.external:
152			self.file.close()
153
154			def __next__(self):
155			return self.next()
156
157			def next(self):
158			"""Return the next entry in the archive."""
159			if self.closed:
160			raise ValueError('next operation on closed file')
161			if self._ptr > len(self._infos):
162			raise StopIteration()
163			ret = self._infos[self._ptr]
164			self._ptr += 1
165			return ret
166
167			def __iter__(self):
168			return iter(self._infos)
169
170			def _readfile(self, name):
171			self._readobj(open(name, 'rb'))
172
173			def _readobj(self, fileobj):
174			self.file = fileobj
175			start = self.file.tell()
176			istart = self.file.tell()
177			text = self.file.read(110)
178			while text:
179			namelen = int(text[94:102], 16)
180			text += self.file.read(namelen)
181			ce = CpioEntry(text, self, istart)
182			if not ce.name == "TRAILER!!!":
183			self._infos.append(ce)
184			else:
185			return
186			self.file.seek((4-(self.file.tell()-istart) % 4) % 4, 1)
187			self.file.seek(self._infos[-1].size, 1)
188			self.file.seek((4-(self.file.tell()-istart) % 4) % 4, 1)
189
190			istart = self.file.tell()
191			text = self.file.read(110)
192			else:
193			raise CpioError('premature end of headers')
194

OpenSCAP / oscap-anaconda-addon

Pull Request — master (#140)

CpioArchive.__next__() A

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CpioArchive.next() A