README
author Vadim Gelfer <vadim.gelfer@gmail.com>
Fri, 24 Mar 2006 09:08:12 -0800
changeset 1998 65cc17ae9649
parent 1308 2073e5a71008
child 2031 d242719c716e
permissions -rw-r--r--
fix race in localrepo.addchangegroup. localrepo.addchangegroup writes to changelog, then manifest, then normal files. this breaks access ordering. if reader reads changelog while manifest is being written, can find pointers into places in manifest that are not yet written. same can happen for manifest and normal files. fix is to make almost no change to localrepo.addchangegroup. it must to write changelog and manifest data early because it has to read them while writing other files. instead, write changelog and manifest data to temp file that reader cannot see, then append temp data to manifest after all normal files written, finally append temp data to changelog. temp file code is in new appendfile module. can be used in other places with small changes. much smaller race still left. we write all new data in one write call, but reader can maybe see partial update because python or os or filesystem cannot always make write really atomic. file locking no help: slow, not portable, not reliable over nfs. only real safe other plan is write to temp file every time and rename, but performance bad when manifest or changelog is big.

MERCURIAL QUICK-START

Setting up Mercurial:

 Note: some distributions fails to include bits of distutils by
 default, you'll need python-dev to install. You'll also need a C
 compiler and a 3-way merge tool like merge, tkdiff, or kdiff3.

 First, unpack the source:

 $ tar xvzf mercurial-<ver>.tar.gz
 $ cd mercurial-<ver>

 To install system-wide:

 $ python setup.py install   # change python to python2.3 if 2.2 is default

 To install in your home directory (~/bin and ~/lib, actually), run:

 $ python2.3 setup.py install --home=~
 $ export PYTHONPATH=${HOME}/lib/python  # (or lib64/ on some systems)
 $ export PATH=${HOME}/bin:$PATH         # add these to your .bashrc

 And finally:

 $ hg                                    # test installation, show help

 If you get complaints about missing modules, you probably haven't set
 PYTHONPATH correctly.

Setting up a Mercurial project:

 $ cd project/
 $ hg init         # creates .hg
 $ hg addremove    # add all unknown files and remove all missing files
 $ hg commit       # commit all changes, edit changelog entry

 Mercurial will look for a file named .hgignore in the root of your
 repository which contains a set of regular expressions to ignore in
 file paths.

Branching and merging:

 $ hg clone linux linux-work    # create a new branch
 $ cd linux-work
 $ <make changes>
 $ hg commit
 $ cd ../linux
 $ hg pull ../linux-work     # pull changesets from linux-work
 $ hg update -m              # merge the new tip from linux-work into
                             # our working directory
 $ hg commit                 # commit the result of the merge

Importing patches:

 Fast:
 $ patch < ../p/foo.patch
 $ hg addremove
 $ hg commit

 Faster:
 $ patch < ../p/foo.patch
 $ hg commit `lsdiff -p1 ../p/foo.patch`

 Fastest:
 $ cat ../p/patchlist | xargs hg import -p1 -b ../p

Exporting a patch:

 (make changes)
 $ hg commit
 $ hg tip
 28237:747a537bd090880c29eae861df4d81b245aa0190
 $ hg export 28237 > foo.patch    # export changeset 28237

Network support:

 # pull from the primary Mercurial repo
 foo$ hg clone http://selenic.com/hg/
 foo$ cd hg

 # export your current repo via HTTP with browsable interface
 foo$ hg serve -n "My repo" -p 80

 # pushing changes to a remote repo with SSH
 foo$ hg push ssh://user@example.com/~/hg/

 # merge changes from a remote machine
 bar$ hg pull http://foo/
 bar$ hg update -m        # merge changes into your working directory

 # Set up a CGI server on your webserver
 foo$ cp hgweb.cgi ~/public_html/hg/index.cgi
 foo$ emacs ~/public_html/hg/index.cgi # adjust the defaults

For more info:

 Documentation in doc/
 Mercurial website at http://selenic.com/mercurial
 Mercurial wiki at http://selenic.com/mercurial/wiki