def save(self, filename=None, v1=1, v2_version=4, v23_sep='/'):
        """Save changes to a file.

        If no filename is given, the one most recently loaded is used.

        Keyword arguments:
        v1 -- if 0, ID3v1 tags will be removed
              if 1, ID3v1 tags will be updated but not added
              if 2, ID3v1 tags will be created and/or updated
        v2 -- version of ID3v2 tags (3 or 4).

        By default Mutagen saves ID3v2.4 tags. If you want to save ID3v2.3
        tags, you must call method update_to_v23 before saving the file.

        v23_sep -- the separator used to join multiple text values
                   if v2_version == 3. Defaults to '/' but if it's None
                   will be the ID3v2v2.4 null separator.

        The lack of a way to update only an ID3v1 tag is intentional.
        """

        framedata = self._prepare_framedata(v2_version, v23_sep)
        framesize = len(framedata)

        if not framedata:
            try:
                self.delete(filename)
            except EnvironmentError as err:
                from errno import ENOENT
                if err.errno != ENOENT:
                    raise
            return

        if filename is None:
            filename = self.filename
        try:
            f = open(filename, 'rb+')
        except IOError as err:
            from errno import ENOENT
            if err.errno != ENOENT:
                raise
            f = open(filename, 'ab')  # create, then reopen
            f = open(filename, 'rb+')
        try:
            idata = f.read(10)

            header = self._prepare_id3_header(idata, framesize, v2_version)
            header, outsize, insize = header

            data = header + framedata + (b'\x00' * (outsize - framesize))

            if (insize < outsize):
                insert_bytes(f, outsize - insize, insize + 10)
            f.seek(0)
            f.write(data)

            self.__save_v1(f, v1)

        finally:
            f.close()

    def __save_new(self, fileobj, atoms, ilst_data, padding_func):
        hdlr = Atom.render(b"hdlr", b"\x00" * 8 + b"mdirappl" + b"\x00" * 9)
        meta_data = b"\x00\x00\x00\x00" + hdlr + ilst_data

        try:
            path = atoms.path(b"moov", b"udta")
        except KeyError:
            path = atoms.path(b"moov")

        offset = path[-1]._dataoffset

        # ignoring some atom overhead... but we don't have padding left anyway
        # and padding_size is guaranteed to be less than zero
        content_size = get_size(fileobj) - offset
        padding_size = -len(meta_data)
        assert padding_size < 0
        info = PaddingInfo(padding_size, content_size)
        new_padding = info._get_padding(padding_func)
        new_padding = min(0xFFFFFFFF, new_padding)

        free = Atom.render(b"free", b"\x00" * new_padding)
        meta = Atom.render(b"meta", meta_data + free)
        if path[-1].name != b"udta":
            # moov.udta not found -- create one
            data = Atom.render(b"udta", meta)
        else:
            data = meta

        insert_bytes(fileobj, len(data), offset)
        fileobj.seek(offset)
        fileobj.write(data)
        self.__update_parents(fileobj, path, len(data))
        self.__update_offsets(fileobj, atoms, len(data), offset)

    def test_insert_bytes(self):
        from mutagen._util import insert_bytes

        expected_content = 'foo\nbaz\nbar\n'

        self.mount()
        try:
            self._init_mmap()
            try:
                insert_bytes(self.file_obj, 4, 4)
                self.file_obj.seek(4)
                self.file_obj.write('baz\n')
                self.file_obj.seek(0)
                content = self.file_obj.read()
                self.assertEqual(content, expected_content)

                self.file_obj.close()
                self.file_obj = self._open_file()
                content = self.file_obj.read()
                self.assertEqual(content, expected_content)
            finally:
                self._de_init_mmap()
        finally:
            self.umount()
        self.clean_up()

 def test_insert_6106_79_51760(self):
     # This appears to be due to ANSI C limitations in read/write on rb+
     # files. The problematic behavior only showed up in our mmap fallback
     # code for transfers of this or similar sizes.
     data = b''.join(str(x).encode('ascii') for x in range(12574)) # 51760 bytes
     o = self.file(data)
     insert_bytes(o, 6106, 79)
     self.failUnless(data[:6106+79] + data[79:] == self.read(o))

 def __save_new(self, fileobj, atoms, ilst, offset):
     hdlr = Atom.render("hdlr", "\x00" * 8 + "mdirappl" + "\x00" * 9)
     meta = Atom.render("meta", "\x00\x00\x00\x00" + hdlr + ilst)
     moov, udta = atoms.path("moov", "udta")
     insert_bytes(fileobj, len(meta), udta.offset + offset + 8)
     fileobj.seek(udta.offset + offset + 8)
     fileobj.write(meta)
     self.__update_parents(fileobj, [moov, udta], len(meta), offset)

    def save(self):
        # Move attributes to the right objects
        self.to_extended_content_description = {}
        self.to_metadata = {}
        self.to_metadata_library = []
        for name, value in self.tags:
            if name in _standard_attribute_names:
                continue
            large_value = value.data_size() > 0xFFFF
            if (value.language is None and value.stream is None and
                name not in self.to_extended_content_description and
                not large_value):
                self.to_extended_content_description[name] = value
            elif (value.language is None and value.stream is not None and
                  name not in self.to_metadata and not large_value):
                self.to_metadata[name] = value
            else:
                self.to_metadata_library.append((name, value))

        # Add missing objects
        if not self.content_description_obj:
            self.content_description_obj = \
                ContentDescriptionObject()
            self.objects.append(self.content_description_obj)
        if not self.extended_content_description_obj:
            self.extended_content_description_obj = \
                ExtendedContentDescriptionObject()
            self.objects.append(self.extended_content_description_obj)
        if not self.header_extension_obj:
            self.header_extension_obj = \
                HeaderExtensionObject()
            self.objects.append(self.header_extension_obj)
        if not self.metadata_obj:
            self.metadata_obj = \
                MetadataObject()
            self.header_extension_obj.objects.append(self.metadata_obj)
        if not self.metadata_library_obj:
            self.metadata_library_obj = \
                MetadataLibraryObject()
            self.header_extension_obj.objects.append(self.metadata_library_obj)

        # Render the header
        data = "".join([obj.render(self) for obj in self.objects])
        data = (HeaderObject.GUID +
                struct.pack("<QL", len(data) + 30, len(self.objects)) +
                "\x01\x02" + data)

        fileobj = open(self.filename, "rb+")
        try:
            size = len(data)
            if size > self.size:
                insert_bytes(fileobj, size - self.size, self.size)
            if size < self.size:
                delete_bytes(fileobj, self.size - size, 0)
            fileobj.seek(0)
            fileobj.write(data)
        finally:
            fileobj.close()

    def save(self, filename=None, deleteid3=False):
        """Save metadata blocks to a file.

        If no filename is given, the one most recently loaded is used.
        """

        if filename is None: filename = self.filename
        f = open(filename, 'rb+')

        try:
            # Ensure we've got padding at the end, and only at the end.
            # If adding makes it too large, we'll scale it down later.
            self.metadata_blocks.append(Padding('\x00' * 1020))
            MetadataBlock.group_padding(self.metadata_blocks)

            header = self.__check_header(f)
            available = self.__find_audio_offset(f) - header  # "fLaC" and maybe ID3
            data = MetadataBlock.writeblocks(self.metadata_blocks)

            # Delete ID3v2
            if deleteid3 and header > 4:
                available += header - 4
                header = 4

            if len(data) > available:
                # If we have too much data, see if we can reduce padding.
                padding = self.metadata_blocks[-1]
                newlength = padding.length - (len(data) - available)
                if newlength > 0:
                    padding.length = newlength
                    data = MetadataBlock.writeblocks(self.metadata_blocks)
                    assert len(data) == available

            elif len(data) < available:
                # If we have too little data, increase padding.
                self.metadata_blocks[-1].length += (available - len(data))
                data = MetadataBlock.writeblocks(self.metadata_blocks)
                assert len(data) == available

            if len(data) != available:
                # We couldn't reduce the padding enough.
                diff = (len(data) - available)
                insert_bytes(f, diff, header)

            f.seek(header - 4)
            f.write("fLaC" + data)

            # Delete ID3v1
            if deleteid3:
                try: f.seek(-128, 2)
                except IOError: pass
                else:
                    if f.read(3) == "TAG":
                        f.seek(-128, 2)
                        f.truncate()
        finally:
            f.close()

 def test_insert_6106_79_51760(self):
     # This appears to be due to ANSI C limitations in read/write on rb+
     # files. The problematic behavior only showed up in our mmap fallback
     # code for transfers of this or similar sizes.
     data = u''.join(map(text_type, xrange(12574)))  # 51760 bytes
     data = data.encode("ascii")
     with self.file(data) as o:
         insert_bytes(o, 6106, 79)
         self.failUnless(data[:6106 + 79] + data[79:] == self.read(o))

    def replace(klass, fileobj, old_pages, new_pages):
        """Replace old_pages with new_pages within fileobj.

        old_pages must have come from reading fileobj originally.
        new_pages are assumed to have the 'same' data as old_pages,
        and so the serial and sequence numbers will be copied, as will
        the flags for the first and last pages.

        fileobj will be resized and pages renumbered as necessary. As
        such, it must be opened r+b or w+b.
        """

        # Number the new pages starting from the first old page.
        first = old_pages[0].sequence
        for page, seq in zip(new_pages, range(first, first + len(new_pages))):
            page.sequence = seq
            page.serial = old_pages[0].serial

        new_pages[0].first = old_pages[0].first
        new_pages[0].last = old_pages[0].last
        new_pages[0].continued = old_pages[0].continued

        new_pages[-1].first = old_pages[-1].first
        new_pages[-1].last = old_pages[-1].last
        new_pages[-1].complete = old_pages[-1].complete
        if not new_pages[-1].complete and len(new_pages[-1].packets) == 1:
            new_pages[-1].position = -1L

        new_data = "".join(map(klass.write, new_pages))

        # Make room in the file for the new data.
        delta = len(new_data)
        fileobj.seek(old_pages[0].offset, 0)
        insert_bytes(fileobj, delta, old_pages[0].offset)
        fileobj.seek(old_pages[0].offset, 0)
        fileobj.write(new_data)
        new_data_end = old_pages[0].offset + delta

        # Go through the old pages and delete them. Since we shifted
        # the data down the file, we need to adjust their offsets. We
        # also need to go backwards, so we don't adjust the deltas of
        # the other pages.
        old_pages.reverse()
        for old_page in old_pages:
            adj_offset = old_page.offset + delta
            delete_bytes(fileobj, old_page.size, adj_offset)

        # Finally, if there's any discrepency in length, we need to
        # renumber the pages for the logical stream.
        if len(old_pages) != len(new_pages):
            fileobj.seek(new_data_end, 0)
            serial = new_pages[-1].serial
            sequence = new_pages[-1].sequence + 1
            klass.renumber(fileobj, serial, sequence)

 def __save_existing(self, fileobj, atoms, path, data, offset):
     # Replace the old ilst atom.
     ilst = path.pop()
     delta = len(data) - ilst.length
     fileobj.seek(ilst.offset + offset)
     if delta > 0:
         insert_bytes(fileobj, delta, ilst.offset + offset)
     elif delta < 0:
         delete_bytes(fileobj, -delta, ilst.offset + offset)
     fileobj.seek(ilst.offset + offset)
     fileobj.write(data)
     self.__update_parents(fileobj, path, delta, offset)

    def save(self, filething=None, v1=1, v2_version=4, v23_sep='/',
             padding=None):
        """save(filething=None, v1=1, v2_version=4, v23_sep='/', padding=None)

        Save changes to a file.

        Args:
            filething (filething):
                Filename to save the tag to. If no filename is given,
                the one most recently loaded is used.
            v1 (ID3v1SaveOptions):
                if 0, ID3v1 tags will be removed.
                if 1, ID3v1 tags will be updated but not added.
                if 2, ID3v1 tags will be created and/or updated
            v2 (int):
                version of ID3v2 tags (3 or 4).
            v23_sep (text):
                the separator used to join multiple text values
                if v2_version == 3. Defaults to '/' but if it's None
                will be the ID3v2v2.4 null separator.
            padding (:obj:`mutagen.PaddingFunction`)

        Raises:
            mutagen.MutagenError

        By default Mutagen saves ID3v2.4 tags. If you want to save ID3v2.3
        tags, you must call method update_to_v23 before saving the file.

        The lack of a way to update only an ID3v1 tag is intentional.
        """

        f = filething.fileobj

        try:
            header = ID3Header(filething.fileobj)
        except ID3NoHeaderError:
            old_size = 0
        else:
            old_size = header.size

        data = self._prepare_data(
            f, 0, old_size, v2_version, v23_sep, padding)
        new_size = len(data)

        if (old_size < new_size):
            insert_bytes(f, new_size - old_size, old_size)
        elif (old_size > new_size):
            delete_bytes(f, old_size - new_size, new_size)
        f.seek(0)
        f.write(data)

        self.__save_v1(f, v1)

 def __save_new(self, fileobj, atoms, ilst):
     hdlr = Atom.render("hdlr", "\x00" * 8 + "mdirappl" + "\x00" * 9)
     meta = Atom.render("meta", "\x00\x00\x00\x00" + hdlr + ilst + self.__pad_ilst(ilst))
     try:
         path = atoms.path("moov", "udta")
     except KeyError:
         # moov.udta not found -- create one
         path = atoms.path("moov")
         meta = Atom.render("udta", meta)
     offset = path[-1].offset + 8
     insert_bytes(fileobj, len(meta), offset)
     fileobj.seek(offset)
     fileobj.write(meta)
     self.__update_parents(fileobj, path, len(meta))
     self.__update_offsets(fileobj, atoms, len(meta), offset)

    def save(self, filename=None, v2_version=4, v23_sep='/'):
        """Save ID3v2 data to the AIFF file"""

        framedata = self._prepare_framedata(v2_version, v23_sep)
        framesize = len(framedata)

        if filename is None:
            filename = self.filename

        # Unlike the parent ID3.save method, we won't save to a blank file
        # since we would have to construct a empty AIFF file
        fileobj = open(filename, 'rb+')
        iff_file = IFFFile(fileobj)

        try:
            if u'ID3' not in iff_file:
                iff_file.insert_chunk(u'ID3')

            chunk = iff_file[u'ID3']
            fileobj.seek(chunk.data_offset)

            header = fileobj.read(10)
            header = self._prepare_id3_header(header, framesize, v2_version)
            header, new_size, _ = header

            data = header + framedata + (b'\x00' * (new_size - framesize))

            # Include ID3 header size in 'new_size' calculation
            new_size += 10

            # Expand the chunk if necessary, including pad byte
            if new_size > chunk.size:
                insert_at = chunk.offset + chunk.size
                insert_size = new_size - chunk.size + new_size % 2
                insert_bytes(fileobj, insert_size, insert_at)
                chunk.resize(new_size)

            fileobj.seek(chunk.data_offset)
            fileobj.write(data)
        finally:
            fileobj.close()

    def test_many_changes(self, num_runs=5, num_changes=300,
                          min_change_size=500, max_change_size=1000,
                          min_buffer_size=1, max_buffer_size=2000):
        self.failUnless(min_buffer_size < min_change_size and
                        max_buffer_size > max_change_size and
                        min_change_size < max_change_size and
                        min_buffer_size < max_buffer_size,
                        "Given testing parameters make this test useless")
        for j in xrange(num_runs):
            data = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ" * 1024
            fobj = self.file(data)
            filesize = len(data)
            # Generate the list of changes to apply
            changes = []
            for i in xrange(num_changes):
                change_size = random.randrange(
                    min_change_size, max_change_size)
                change_offset = random.randrange(0, filesize)
                filesize += change_size
                changes.append((change_offset, change_size))

            # Apply the changes, and make sure they all took.
            for offset, size in changes:
                buffer_size = random.randrange(
                    min_buffer_size, max_buffer_size)
                insert_bytes(fobj, size, offset, BUFFER_SIZE=buffer_size)
            fobj.seek(0)
            self.failIfEqual(fobj.read(len(data)), data)
            fobj.seek(0, 2)
            self.failUnlessEqual(fobj.tell(), filesize)

            # Then, undo them.
            changes.reverse()
            for offset, size in changes:
                buffer_size = random.randrange(
                    min_buffer_size, max_buffer_size)
                delete_bytes(fobj, size, offset, BUFFER_SIZE=buffer_size)
            fobj.seek(0)
            self.failUnless(fobj.read() == data)

    def __save_existing(self, fileobj, atoms, path, data):
        # Replace the old ilst atom.
        ilst = path.pop()
        offset = ilst.offset
        length = ilst.length

        # Check for padding b"free" atoms
        meta = path[-1]
        index = meta.children.index(ilst)
        try:
            prev = meta.children[index-1]
            if prev.name == b"free":
                offset = prev.offset
                length += prev.length
        except IndexError:
            pass
        try:
            next = meta.children[index+1]
            if next.name == b"free":
                length += next.length
        except IndexError:
            pass

        delta = len(data) - length
        if delta > 0 or (delta < 0 and delta > -8):
            data += self.__pad_ilst(data)
            delta = len(data) - length
            insert_bytes(fileobj, delta, offset)
        elif delta < 0:
            data += self.__pad_ilst(data, -delta - 8)
            delta = 0

        fileobj.seek(offset)
        fileobj.write(data)
        self.__update_parents(fileobj, path, delta)
        self.__update_offsets(fileobj, atoms, delta, offset)

 def test_smaller_than_file_across_end(self):
     o = self.file(b'abcdefghij')
     insert_bytes(o, 4, 8)
     self.assertEquals(b'abcdefghij\x00\x00ij', self.read(o))

 def test_smaller_than_file_to_end(self):
     o = self.file(b'abcdefghij')
     insert_bytes(o, 4, 6)
     self.assertEquals(b'abcdefghijghij', self.read(o))

 def test_smaller_than_file_middle(self):
     o = self.file(b'abcdefghij')
     insert_bytes(o, 4, 4)
     self.assertEquals(b'abcdefghefghij', self.read(o))

 def test_insert_after_one(self):
     o = self.file(b'a')
     insert_bytes(o, 8, 1)
     self.assertEquals(b'a' + b'\x00' * 8, self.read(o))

 def test_insert_before_one(self):
     o = self.file(b'a')
     insert_bytes(o, 8, 0)
     self.assertEquals(b'a' + b'\x00' * 7 + b'a', self.read(o))