Mercurial > hg
view tests/test-empty-group.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 | 301725c3df9a |
children | eb586ed5d8ce |
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# A B # # 3 4 3 # |\/| |\ # |/\| | \ # 1 2 1 2 # \ / \ / # 0 0 # # if the result of the merge of 1 and 2 # is the same in 3 and 4, no new manifest # will be created and the manifest group # will be empty during the pull # # (plus we test a failure where outgoing # wrongly reported the number of csets) $ hg init a $ cd a $ touch init $ hg ci -A -m 0 adding init $ touch x y $ hg ci -A -m 1 adding x adding y $ hg update 0 0 files updated, 0 files merged, 2 files removed, 0 files unresolved $ touch x y $ hg ci -A -m 2 adding x adding y created new head $ hg merge 1 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -A -m m1 $ hg update -C 1 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg merge 2 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -A -m m2 created new head $ cd .. $ hg clone -r 3 a b adding changesets adding manifests adding file changes added 4 changesets with 3 changes to 3 files updating to branch default 3 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg clone -r 4 a c adding changesets adding manifests adding file changes added 4 changesets with 3 changes to 3 files updating to branch default 3 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg -R a outgoing b comparing with b searching for changes changeset: 4:1ec3c74fc0e0 tag: tip parent: 1:79f9e10cd04e parent: 2:8e1bb01c1a24 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: m2 $ hg -R a outgoing c comparing with c searching for changes changeset: 3:d15a0c284984 parent: 2:8e1bb01c1a24 parent: 1:79f9e10cd04e user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: m1 $ hg -R b outgoing c comparing with c searching for changes changeset: 3:d15a0c284984 tag: tip parent: 2:8e1bb01c1a24 parent: 1:79f9e10cd04e user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: m1 $ hg -R c outgoing b comparing with b searching for changes changeset: 3:1ec3c74fc0e0 tag: tip parent: 1:79f9e10cd04e parent: 2:8e1bb01c1a24 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: m2 $ hg -R b pull a pulling from a searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg -R c pull a pulling from a searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge)