mirror of
https://github.com/vbatts/tar-split.git
synced 2024-11-15 04:58:36 +00:00
44 lines
1.5 KiB
Markdown
44 lines
1.5 KiB
Markdown
asm
|
|
===
|
|
|
|
This library for assembly and disassembly of tar archives, facilitated by
|
|
`github.com/vbatts/tar-split/tar/storage`.
|
|
|
|
|
|
Concerns
|
|
--------
|
|
|
|
For completely safe assembly/disassembly, there will need to be a Content
|
|
Addressable Storage (CAS) directory, that maps to a checksum in the
|
|
`storage.Entity` of `storage.FileType`.
|
|
|
|
This is due to the fact that tar archives _can_ allow multiple records for the
|
|
same path, but the last one effectively wins. Even if the prior records had a
|
|
different payload.
|
|
|
|
In this way, when assembling an archive from relative paths, if the archive has
|
|
multiple entries for the same path, then all payloads read in from a relative
|
|
path would be identical.
|
|
|
|
|
|
Thoughts
|
|
--------
|
|
|
|
Have a look-aside directory or storage. This way when a clobbering record is
|
|
encountered from the tar stream, then the payload of the prior/existing file is
|
|
stored to the CAS. This way the clobbering record's file payload can be
|
|
extracted, but we'll have preserved the payload needed to reassemble a precise
|
|
tar archive.
|
|
|
|
clobbered/path/to/file.[0-N]
|
|
|
|
*alternatively*
|
|
|
|
We could just _not_ support tar streams that have clobbering file paths.
|
|
Appending records to the archive is not incredibly common, and doesn't happen
|
|
by default for most implementations. Not supporting them wouldn't be a
|
|
security concern either, as if it did occur, we would reassemble an archive
|
|
that doesn't validate signature/checksum, so it shouldn't be trusted anyway.
|
|
|
|
Otherwise, this will allow us to defer support for appended files as a FUTURE FEATURE.
|
|
|