大文件版本控制工具 bfsync 0.2.0 發布

bfsync 是一個為大文件提供 git 風格的版本控制的程序，文件內容使用 bfsync 管理，使用 git 資料庫來完成版本控制，資料庫只存儲數據文件的哈希值。

該版本幾乎進行了整個項目重寫，再基于 git ，而是使用 SQLite 數據庫存儲內容；使用 FuSE 文件系統來查看和編輯資料庫內容；改進了版本歷史記錄；存儲更多的元數據，包括用戶、組和硬鏈接、設備等。

Bfsync能夠實現：

• synchronize a collection of big files between many machines, where the collection is changed independently on different machines

• offline commits, so you can change files and commit on your laptop and resynchronize as soon as you have network connectivity again

• file-level deduplication, so storing a file twice under different names will not use more space than storing it once - also renames or removing a file and re-adding it will not retransfer the data, if the repository already has it

• storing all attributes, bfsync stores everything a normal filesystem would store, like user/group settings, permissions, symlinks, hard links, devices, ... (this is useful for backups)

• storing each file only once: many version control systems store files two times on the users machines, once internally and a second time as "checkout"; especially for huge files (mp3s, photos, videos) this is not convenient. bfsync stores each file only once, and provides a view on the data in the FuSE filesystem; it uses copy-on-write if a file is modified

• old versions remain available: bfsync keeps all files and all versions available in each checkout; within the filesystem there is a .bfsync/commits/N directory for all commits, so you can look at all old versions from within the filesystem

• rate-limiting: since big files take extremely long to transfer, bfsync allows to limit the bandwidth used for file transfer, so it can run in background without disturbing your normal work