Mercurial > hg
view tests/test-no-symlinks.t @ 27430:e240e914d226 stable
revlog: seek to end of file before writing (issue4943)
Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.
Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.
The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.
Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.
This patch appears to have little to no impact on performance on my
Linux machine.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 17 Dec 2015 17:16:02 -0800 |
parents | 7a9cbb315d84 |
children | 2d49d2eb1ff2 |
line wrap: on
line source
#require no-symlink # The following script was used to create the bundle: # # hg init symlinks # cd symlinks # echo a > a # mkdir d # echo b > d/b # ln -s a a.lnk # ln -s d/b d/b.lnk # hg ci -Am t # hg bundle --base null ../test-no-symlinks.hg Extract a symlink on a platform not supporting them $ hg init t $ cd t $ hg pull -q "$TESTDIR/bundles/test-no-symlinks.hg" $ hg update 4 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat a.lnk && echo a $ cat d/b.lnk && echo d/b Copy a symlink and move another $ hg copy a.lnk d/a2.lnk $ hg mv d/b.lnk b2.lnk $ hg ci -Am copy $ cat d/a2.lnk && echo a $ cat b2.lnk && echo d/b Bundle and extract again $ hg bundle --base null ../symlinks.hg 2 changesets found $ cd .. $ hg init t2 $ cd t2 $ hg pull ../symlinks.hg pulling from ../symlinks.hg requesting all changes adding changesets adding manifests adding file changes added 2 changesets with 6 changes to 6 files (run 'hg update' to get a working copy) $ hg update 5 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat a.lnk && echo a $ cat d/a2.lnk && echo a $ cat b2.lnk && echo d/b