main module

Backshift: A deduplicating backup script with expiration.

class main.Options

Bases: object

Just hold our command line options.

class main.Progress_report(type_)

Bases: object

A class for describing what kind of progress report to give during a backup.

main.absolutize(directory_at_outset, filename)

Make a filename absolute.

If filename is relative, make it absolute relative to the CWD when the program was started, as indicated by directory_at_outset

main.ascii_ize(binary)

Replace non-ASCII characters with question marks; otherwise writing to sys.stdout tracebacks.

main.backup_full_poststat_stats(filelist, repo, directory_at_outset)

Do a backup - assume find lists filenames only - we add the sizes.

main.backup_full_prestat_stats(filelist, repo, directory_at_outset)

Do a backup - assume find has prefixed filenames with sizes separated by a space.

main.backup_full_progress_report(filelist, repo, directory_at_outset, get_records)

Produce a backup. Inhale the filenames, and give a percent complete as we go.

We treat bytes in a file as bytes in a file, and metadata is always assumed metadata_size bytes.

main.backup_minimal_stats(filelist, repo, directory_at_outset)

Produce a backup. Don’t inhale the filenames, and don’t give a percent complete as we go.

main.backup_moderate_stats(filelist, repo, directory_at_outset)

Create a backup with moderate progress output.

Inhale the filenames, and give a percent complete by bytes as we go. We pretend every byte takes the same amount of time.

main.backup_no_stats(filelist, repo, directory_at_outset)

Produce a backup. Don’t inhale the filenames, and don’t give a percent complete as we go.

main.check_options(options)

Make sure the options combine well - error out if not.

main.get_full_poststat_progress_recs(filelist, repo, directory_at_outset)

Produce a backup with poststat progress.

Read the records for a full+poststat progress report. Use stat to compute file sizes before we start backing anything up.

main.get_full_prestat_progress_recs(filelist, repo, directory_at_outset)

Read the records for a full+prestat progress report. Assume we’ll get sizeblankfilename0 on each line of input.

main.handle_savedir(save_directory, init_savedir)

Maybe create savedir, maybe error about savedir - depending on init-savedir.

We only create it if it doesn’t yet exist, and init_savedir is True.

main.main()

Operations available follow.

• perform a backup

• restore a backup

• list backups available

• list files within a backup

• or expire old files.

main.output_filename(filename, add_eol=True)

Output a filename to the tty (stdout), taking into account that some tty’s do not allow non-ASCII characters.

main.parse_options()

Stick the command line options in a container as useful variables.

main.perform_expire(starting_directory, check_hashes)

Expire old chunks and savesets from a repository.

main.perform_get_chunk(starting_directory, hash_string)

Output one chunk to stdout.

main.perform_get_metadata(repo, backup_id, save_directory, filename)

Output one file’s metadata to stdout.

main.perform_list_backup(repo, backup_id, starting_directory, recursive=True)

List all files within a backup along the lines of ‘tar tvf’.

main.perform_list_backup_simply(repo, backup_id, starting_directory, recursive=True)

List all files within a backup along the lines of ‘tar tf’.

main.perform_list_backups(repo, last_n)

List all the backups in a repository.

main.produce_tar(repo, backup_id, starting_directory, recursive=True, tar_format='default')

Dump content in tar format for restoration or offsite backup.

main.strip_start(string, possible_prefixes)

Strip a prefix.

If string starts with one of the prefixes in possible_prefixes, strip off the prefix and return it. Otherwise, return the string unchanged.

main.usage(retval)

Print a usage message, exit with passed exit code.