----------------------- Version Control Systems ----------------------- :For: VAGUE :Date: 2007-03-20 :Authors: Forest Bond, Paul Flint, Josh Sled, Andrew Tomczak :Hosted By: `ClearBearing `_ .. footer:: 2007-03-20 — VAGUE Version Control Systems ----------------------- - Track a set of changes to directories of files. - Files/directory names, contents. - Textual, line-oriented changes - Metadata - Authorship, timestamp, history, change logs/descriptions - Filesystem Permissions - Branches: separate, named unrelated sets of changes. - Integration of changes from other sources. Core Concepts ------------- - *repository* - *commit* the current state of a set of files/directories - including metadata - view *history*; retreive a previous version - *extract* changes for exchange Good for? --------- - source code - markup - documentation (html, DocBook, text) - web sites - configuration - text files - binary object history - Images (Gimp, P'shop, Inkscape/SVG, ...) - Microsoft Word^W^W opaque document formats - ...? Distributed vs. Centralized --------------------------- - Centralized - The One True Repository. - The "commit" operation is done synchronously against that repository. - Checkouts usually only have local/*very* partial state. - Some history operations probably aren't possible without the repository. - Distributed - There are multiple independently complete repositories. - Commits are usually local and independent. - Synchronization is done via patch exchange. - Authority is social, not technical. Presentations ------------- - Subversion (svn) — Andrew Tomczak - `SVK `_ — Forest Bond - git — Josh Sled - `Mercurial `_ (hg) — Forest Bond - darcs — Josh Sled - Bazzar (bzr) — Paul Flint - discussion; next meeting planning Subversion (svn) ---------------- Andrew... git and git-svn --------------- :Author: jsled :Date: 2007-03-20 Overview -------- `git`_ - Created by Linus Torvalds - After "The BitKeeper Debacle". - Borne of handling patches for the kernel - Monotone = good but slow - Inspiration from BK, Monotone, quilt - pragmatically tuned - BK = 10-15 seconds/patch - git = 6.7 patches/second - maintained by Junio C. Hamano, a development-phase contributor .. _git: http://git.or.cz/ .. container:: handout Other resources: - Basic theory of operation ------------------------- - tool for the application of many coherent patches - major parts - working copy - index ("cache") - database repository - toolkit design: many small, single-purpose applications - plumbing - very low level operations - porcelains - front-ends, higher-level operation The primary commands -------------------- :: $ git clone git://project.org/pub/project.git $ cd project.git # edit files... $ git-add new-stuff $ git-pull # get updates: git-fetch + git-merge $ git-format-patch -stdout \ | sendmail maintainer@project.org (or) $ git-push Commands: core -------------- :: $ git init-db # create a working copy + repository $ git-clone # copy existing wc + repository $ git-{add, rm, mv} $ git-status $ git-commit -a - Changed files aren't picked up automatically. Content is the focus, not the files. Commands: patches ----------------- :: $ git-format-patch - lots of options for formatting email for kernel (general project) patch submission - "[PATCH [n/m]]" subject line, "Signed-off-by: " lines, &c. :: $ git-am $ git-applymbox - Apply patches from a mailbox. :: $ git-revert - Create an anti-patch. Commands: patches ----------------- :: $ git-fetch $ git-merge - plugable merge strategies - resolve: standard 3-way merge - recursive: enhanced 3-way merge - octopus: N-way merge; refuses to do complex merge - ours: merge, but always use current branch. :: $ git-pull - equivalent to ``git-fetch; git-merge`` Commands: network ----------------- :: $ git-daemon - Create a server :: $ git-push - Send changes upstream, using a given protocol. - rsync, ssh, http(s)/dav, git Commands: status/state ---------------------- :: $ git-reset (--{soft,hard}) - This lets you ammend/re-record a commit or throw away local changes. :: $ git-log $ git-diff $ git-show {guid(partial), HEAD[^|^^|~n|^n], branch] - History overview and view. - ``HEAD``, ``HEAD^`` parent, ``HEAD^^`` grandparent, ``HEAD~4`` great-great grand-parent - ``HEAD^n``: first/second/... parent :: $ git-tag - Creates a GPG-signed object in the database Commands: branches ------------------ :: $ git-branch mybranch $ git-checkout mybranch $ git-rebase A---B---C topic / D---E---F---G master A’--B’--C’ topic / D---E---F---G master Commands: misc -------------- :: $ git-prune - Clean up git garbage :: $ git-repack - Delta-encode repository content. Commands: git-bisect -------------------- :: $ git-bisect start $ git-bisect bad # current $ git-bisect good «rev» 500 revisions remain # test $ git-bisect {good, bad} 250 revisions remain # test ... Interesting/unique apsects -------------------------- - Changed files aren't picked up automatically (``git-commit -a``) - front-ends/integration (more "porcelains") - cogito (cg) - StGIT - gitk (tk frontend for browsing git ancestory) - git-gui (tk) - windows portability - uses file system ops that aren't fast on windows - mmap; fork - end of line conventions - permissions model - CVS server emulator git and svn ----------- .. container:: handout Resources: - - - ``git-svnimport``: import an entire svn repository history into git - ``git-svn``: bidirectional tracking of a single svn branch - branch-focused - pulls SVN repo into ``remote/git-svn`` - ``remotes/${GIT_SVN_ID:-git-svn}``, really - you then branch locally from that Example ------- :: $ git-svn init http://svn.project.org/repo/proj/trunk $ git-svn fetch -r12345 # start at a recent revision $ git-svn fetch # fetch everything (since previous) $ git checkout -b local remotes/git-svn # create local branch $ git repack -d # delta-encode state, compress. # hack hack hack $ git commit -a # more hacking $ git commit -a $ git-svn fetch # updates remote/git-svn $ git rebase remotes/git-svn # sync remote changes with local $ git-svn dcommit # push changes to svn, rebase # This will send two commits upstream. git and git-svn --------------- *(fin)* darcs ----- :Author: jsled :Date: 2007-03-20 Overview -------- `darcs`_ - Announced Wed, 9 Apr 2003 on the haskell-cafe mailing list. - Written by Physicist David Roundy. .. _darcs: http://abridgegame.org/darcs/ .. container:: handout Resources - - - - Basic theory of operation ------------------------- - local repository - pristine copy, working copy, history - algebra of patches - commutation of unrelated patches - implicit dependency determination - explicit dependency specification The primary commands -------------------- :: $ darcs get http://project.org/repos/project # edit; create new file $ darcs add $ darcs whatsnew [--summary] $ darcs pull # update $ darcs record $ darcs send (or) darcs push Commands: core -------------- :: $ darcs init - Create a working copy + repository - Uses ``_darcs`` dir. WTF? :: $ darcs get - copy the history of an existing repository :: $ darcs {add, remove, mv} $ darcs whatsnew [--summary] - list unrecorded changes :: $ darcs record Commands: patches ----------------- :: $ darcs send | darcs apply $ darcs pull $ darcs push $ darcs diff - standard/simple diff; '-u' for unified :: $ darcs whatsnew - hunks: diff++ - context-sensitive - supports adding/removing files Commands: patch management -------------------------- :: $ darcs revert - remove new changes; restore your WC to the recorded copy. :: $ darcs unrevert - "oh s#%t!!" undo of revert ... iff nothing has changed. Commands: patch management (cont'd) ----------------------------------- :: $ darcs unrecord - undo a record, leaving the changes in the WC. :: $ darcs ammend-record - append to the previous recorded record Commands: patch management (cont'd) ----------------------------------- :: $ darcs {unpull, obliterate} - unrecord changes and revert :: $ darcs rollback - generates an anti-patch Commands: status/state ---------------------- :: $ darcs changes - changelog-style, history of commits :: $ darcs tag - no version numbers - create names for states with tag :: $ darcs resolve - conflict resolution Commands: branches ------------------ :: $ cp repo-trunk repo-branch - sync patches between branches manually Unique apsects: good -------------------- - explicit dependency specification - "spontaneous branches" - patch records named with prefixes of "RT#123" - subsequent ops can give "-p 'RT#123'". - interactive operation (good?) Unique apsects: bad ------------------- - file metadata/permissions not supported - mentions "/etc" - FAQ says "don't use it for /etc". - no binary-delta support - the FAQ encourages you to use xdelta manually and track the parts via files. :/ - no symlink support - no partial checkout (sub-directory) support - no good charset support - ^Z, \0 -> binary - auto{conf,make} will trash a darcs repo - Because of ``_darcs/current/configure.in`` darcs ----- *fin*