Bakare: modern and simple, yet efficient backup solution

This is pre-alpha, contributions welcome

It does not even have a standalone binary yet, but the engine looks promising. Contributions are welcome :)

Goals for bakare:

• simple deduplication of file data - don't store the same exact file data twice
• advanced deduplication - store files that only changed slightly more efficiently
• survive index corruption
• resilient towards interrupting the backup (create index checkpoints etc)
• fast
• using max bandwidth
• use max cpu
• use max disk I/O
• memory usage limit
• encryption by default - asymmetric, creates a keypair for you
• fuzzy find by file name in stored files
• failure to process one file should not affect any other files
• intermittent network failures should not make the whole process fail (test with random packet drop)
• system suspend/resume should not make the repo become corrupted, even in the presence of other active backup processes running on other computers, targeting same repo - this is where restic fails

Nice to haves:

• daemon that listens for file events and updates a list of files to be backed up on the next backup run - or a continous backup mode - the daemon uploads the file whenever it sees the change
• peer2peer mode - people storing encrypted backups for each other
• relay mode, where daemon works on one or more central points with local storage (e.g. NAS) and various computers sync with that central location. Then though the central locaiton uploads everything to the other location, typically the cloud.

Implementation notes

• automatic node discovery - two roles: data publisher and data persister - should be able to figure out which node is which automatically
• test with randomly created dirs and files, with property based tests and fuzzer
• see if we can use salsa for recomputation
• index corruption tests - mutate random byte and see if everything is readable
• network packet drop tests
• use bevy for decoupling ?
• remove all unwraps

Motivation: All the backup systems I tried are either slow or crashing or both for me

duply: works but is very slow

--------------[ Backup Statistics ]--------------
StartTime 1547198362.85 (Fri Jan 11 09:19:22 2019)
EndTime 1547209509.04 (Fri Jan 11 12:25:09 2019)
ElapsedTime 11146.19 (3 hours 5 minutes 46.19 seconds)
SourceFiles 3065438
SourceFileSize 585041709586 (545 GB)
NewFiles 0
NewFileSize 0 (0 bytes)
DeletedFiles 0
ChangedFiles 0
ChangedFileSize 0 (0 bytes)
ChangedDeltaSize 0 (0 bytes)
DeltaEntries 0
RawDeltaSize 0 (0 bytes)
TotalDestinationSizeChange 111 (111 bytes)
Errors 0
-------------------------------------------------

--- Finished state OK at 12:25:15.000 - Runtime 03:06:43.000 ---

restic:

• crashes with OOM sometimes
• corrupts repo if you suspend one backup process and launch another from a different computer

TODOs

• compare with Kopia