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 if (value.language is None and value.stream is None and name not in self.to_extended_content_description): 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): 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 = file(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 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 delete(self, filename=None): """Remove tags from a file.""" filename = filename or self.filename fileobj = file(filename, "r+b") try: data = _APEv2Data(fileobj) if data.start is not None and data.size is not None: delete_bytes(fileobj, data.end - data.start, data.start) finally: fileobj.close() self.clear()
def save(self, filename=None): """Save changes to a file. If no filename is given, the one most recently loaded is used. Tags are always written at the end of the file, and include a header and a footer. """ filename = filename or self.filename try: fileobj = file(filename, "r+b") except IOError: fileobj = file(filename, "w+b") data = _APEv2Data(fileobj) if data.is_at_start: delete_bytes(fileobj, data.end - data.start, data.start) elif data.start is not None: fileobj.seek(data.start) # Delete an ID3v1 tag if present, too. fileobj.truncate() fileobj.seek(0, 2) # "APE tags items should be sorted ascending by size... This is # not a MUST, but STRONGLY recommended. Actually the items should # be sorted by importance/byte, but this is not feasible." tags = [v._internal(k) for k, v in self.items()] tags.sort(lambda a, b: cmp(len(a), len(b))) num_tags = len(tags) tags = "".join(tags) header = "APETAGEX%s%s" % ( # version, tag size, item count, flags struct.pack("<4I", 2000, len(tags) + 32, num_tags, HAS_HEADER | IS_HEADER), "\0" * 8) fileobj.write(header) fileobj.write(tags) footer = "APETAGEX%s%s" % ( # version, tag size, item count, flags struct.pack("<4I", 2000, len(tags) + 32, num_tags, HAS_HEADER), "\0" * 8) fileobj.write(footer) fileobj.close()