Integrated version control with Fossil SCM

Transcription

1 Integrated version control with Fossil SCM Tech Talk Arne Bachmann Folie 1

2 Overview Web address Author Dr. D.R. Hipp - Author of License GPL v2 Motto No information shall ever get lost Folie 2

3 Fossil principles In Fossil, a revision is called check-in Every file, branch and check-in is an immutable artifact with an artifact identifier (AID), which is a SHA-1 hash E.g. f3859e6842b68349fe e64c4329e4a4 But it suffices to use prefixes (e.g. f385, usually 8 letters) Folie 3

4 Fossil principles Fossil is leightweight Compilation is a matter of seconds, including SQLite code One executable 787kB including self-tests & documentation No dependency whatsoever on external libs or tools: gzip, diff, rsync, Python, Perl, Tcl, Java, Apache, Dbs, patch, Fossil is self-hosted The website fossil-scm.org runs on fossil as CGI Folie 5

5 Usability: Command line interface Comfortable command-line interface Prefixes suffice for commands & AIDs fossil commit fossil rebuild fossil reconstruct fossil co = checkout fossil com fossil reb fossil rec fossil che Symbolic names for check-ins instead of an AID Simple tags on a check-in, starting with symfossil update my_feature_branch Folie 6

6 Usability: Web interface Fossil runs as a web server, provides a comfortable interface fossil ui or fossil server Folie 7

7 Usability: Desktop interface not yet available Folie 8

8 Features Distributed version control system Similar to Mercurial & Bazaar (Python), Git (C), BitKeeper Very fast (pure C code) Data-efficient (stores and syncs (binary) deltas, zlib'ed) Fossil is safe: SQLite manages all data + BLOBs, transactional Extensive self-testing upon each action (zlib-(de)compress), checksumming for every artifact and every action Folie 9

9 Features Very simple and persistent data structures for deltas, tables and file formats No need to dump data off a repository, because each repository is always exactly one file Migration very easy: close, <move>, open No need to import dumped data, because upgrading a repository to a younger fossil executable is that easy: fossil all rebuild Folie 10

10 Fossil: Main building blocks (SCM) Fossil is a VCS, but additionally each repository contains A ticket system (bugtracker) History independent of check-in history A simple Wiki Each wiki page has its own history, independent of check-ins Pages can theoretically be branched and merged But currently no UI or ABI for that Embedded documentation linked with check-ins Reachable by <server>/doc/<dir>/<page>.wiki CSS can be changed via admin options from the UI Folie 11

11 Tags can be attached to any leaf Can have a value (= property), but mostly need none Can be symbolic (starting with sym-) Are passed on to descendants Unless cancelled (fossil tag cancel <name>) Unless merging with another branch There are two default tags: branch=trunk represents the current branch sym-trunk (= NULL) symbolic name of branch After branching sym-trunk: cancelled Folie 12

12 Branching Forking vs. Branching? Fork defined as an "accidental" split of the check-in tree Branch defined as deliberate e.g. a test branch is often merged into the main development branch, point of branch = branch point Merging No integrated conflict editor (but the usual in-file notation) Folie 13

13 Configuration Local configuration state Not shared when pushing, pulling, (auto) syncing Contains settings regarding Used tools commit message editor Web browser (Graphical) diff tool Encryption Proxy Sync options Behaviour (autosync ) Folie 14

14 Configuration fossil help settings Shows integrated help Folie 15

15 Server mode Fossil allows to quickly sync with other developers' repositories fossil server or fossil ui (opens local web browser) fossil push offers changes to remote fossil instance fossil pull loads changes from a remote fossil instance But doesn't change current check-in state (use update) fossil sync pulls and pushes As above Autosync mode offers operation similar to working with a central subversion repository fossil is very flexible Folie 16

16 Server mode Comprehensive web interface allows easy administration Of users and user rights (+ inherited group rights) Settings Appearance Logs Statistics CGI integration Serving multiple repositories Folie 17

17 Additional advantages of Fossil User rights management Uses current login name under Windows/Linux Separate rights for check-ins and web interface users Integrated check-in signing Via PGP/GPG keys or similar Or use --nosign upon commit and branch Robust and reliable Several years of experience in multi-project, multi-gb source trees with thousands of files and check-ins Folie 18

18 Drawbacks Commercial support from a very small company (only 2 persons?) No graphical Windows client available yet Especially no conflict editor and explorer integration Folie 19

19 Thanks for your attention! Questions? Folie 20