Module write

Facilities for writing SquashFS archives.

The most straightforward way to write a SquashFS file from a directory tree on-disk is to use a TreeProcessor. This provides the ability to make “last-minute” modifications to the files that are added, such as skipping certain files or modifying metadata.

To create a totally “synthetic” SquashFS file that is not built from files in a filesystem, open a Writer and feed Sources to it.

Limitations

This library does not yet handle hard links; files with multiple hard links will be archived as separate files with identical contents (which should be deduplicated and end up taking up little additional space).

The SquashFS specification includes a field in directory inodes for the parent inode number, presumably to make .. directory entries work. This is one factor that makes it impossible to build a SquashFS file without building out the entire directory tree to be archived in memory. I have tried as hard as poassible to reduce the amount of data that must be stored for each node added, and this architecture makes it infeasible to store parent inodes in directory entries. I hope to fix this some day, and in the meantime it has not caused problems in the ways I have used the resultant files.

Structs

Source

A single node to be added to the SquashFS archive.

SourceFile

A Source bundled with the path where it should be located.

TreeIterator

An iterator yielding the nodes in a directory tree in a way suitable for archiving.

TreeProcessor

Tool to help create an archive from a directory in the filesystem.

Writer

A basic SquashFS writer.

Enums

BlockFlags

Flags to fine-tune how an entry is added to the archive.

SourceData

Represents the data of a filesystem object that can be added to an archive.