Mercurial > hg
view tests/test-branch-tag-confict.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 |
line wrap: on
line source
Initial setup. $ hg init repo $ cd repo $ touch thefile $ hg ci -A -m 'Initial commit.' adding thefile Create a tag. $ hg tag branchortag Create a branch with the same name as the tag. $ hg branch branchortag marked working directory as branch branchortag (branches are permanent and global, did you want a bookmark?) $ hg ci -m 'Create a branch with the same name as a tag.' This is what we have: $ hg log changeset: 2:10519b3f489a branch: branchortag tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Create a branch with the same name as a tag. changeset: 1:2635c45ca99b user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added tag branchortag for changeset f57387372b5d changeset: 0:f57387372b5d tag: branchortag user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Initial commit. Update to the tag: $ hg up 'tag(branchortag)' 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg parents changeset: 0:f57387372b5d tag: branchortag user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Initial commit. Updating to the branch: $ hg up 'branch(branchortag)' 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg parents changeset: 2:10519b3f489a branch: branchortag tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Create a branch with the same name as a tag. $ cd ..