Mercurial > hg
view tests/test-simple-update.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 | f2719b387380 |
children | 92bca12328d1 |
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$ hg init test $ cd test $ echo foo>foo $ hg addremove adding foo $ hg commit -m "1" $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 1 changesets, 1 total revisions $ hg clone . ../branch updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd ../branch $ hg co 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo bar>>foo $ hg commit -m "2" $ cd ../test $ hg pull ../branch pulling from ../branch searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (run 'hg update' to get a working copy) $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 2 changesets, 2 total revisions $ hg co 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat foo foo bar $ hg manifest --debug 6f4310b00b9a147241b071a60c28a650827fb03d 644 foo update to rev 0 with a date $ hg upd -d foo 0 abort: you can't specify a revision and a date [255] $ cd ..