Mercurial > hg
view tests/test-requires.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 | 4b0fc75f9403 |
children | bd872f64a8ba |
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$ hg init t $ cd t $ echo a > a $ hg add a $ hg commit -m test $ rm .hg/requires $ hg tip abort: index 00changelog.i unknown format 2! [255] $ echo indoor-pool > .hg/requires $ hg tip abort: repository requires features unknown to this Mercurial: indoor-pool! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ echo outdoor-pool >> .hg/requires $ hg tip abort: repository requires features unknown to this Mercurial: indoor-pool outdoor-pool! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ cd .. Test checking between features supported locally and ones required in another repository of push/pull/clone on localhost: $ mkdir supported-locally $ cd supported-locally $ hg init supported $ echo a > supported/a $ hg -R supported commit -Am '#0 at supported' adding a $ echo 'featuresetup-test' >> supported/.hg/requires $ cat > $TESTTMP/supported-locally/supportlocally.py <<EOF > from mercurial import localrepo, extensions > def featuresetup(ui, supported): > for name, module in extensions.extensions(ui): > if __name__ == module.__name__: > # support specific feature locally > supported |= set(['featuresetup-test']) > return > def uisetup(ui): > localrepo.localrepository.featuresetupfuncs.add(featuresetup) > EOF $ cat > supported/.hg/hgrc <<EOF > [extensions] > # enable extension locally > supportlocally = $TESTTMP/supported-locally/supportlocally.py > EOF $ hg -R supported status $ hg init push-dst $ hg -R supported push push-dst pushing to push-dst abort: required features are not supported in the destination: featuresetup-test [255] $ hg init pull-src $ hg -R pull-src pull supported pulling from supported abort: required features are not supported in the destination: featuresetup-test [255] $ hg clone supported clone-dst abort: repository requires features unknown to this Mercurial: featuresetup-test! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ hg clone --pull supported clone-dst abort: required features are not supported in the destination: featuresetup-test [255] $ cd ..