Mercurial > hg
view tests/test-update-reverse.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> |
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date | Thu, 17 Dec 2015 17:16:02 -0800 |
parents | bd625cd4e5e7 |
children | 5c2a4f37eace |
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$ hg init $ touch a $ hg add a $ hg commit -m "Added a" $ touch main $ hg add main $ hg commit -m "Added main" $ hg checkout 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved 'main' should be gone: $ ls a $ touch side1 $ hg add side1 $ hg commit -m "Added side1" created new head $ touch side2 $ hg add side2 $ hg commit -m "Added side2" $ hg log changeset: 3:91ebc10ed028 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added side2 changeset: 2:b932d7dbb1e1 parent: 0:c2eda428b523 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added side1 changeset: 1:71a760306caf user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added main changeset: 0:c2eda428b523 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added a $ hg heads changeset: 3:91ebc10ed028 tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added side2 changeset: 1:71a760306caf user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added main $ ls a side1 side2 $ hg update --debug -C 1 resolving manifests branchmerge: False, force: True, partial: False ancestor: 91ebc10ed028+, local: 91ebc10ed028+, remote: 71a760306caf side1: other deleted -> r removing side1 side2: other deleted -> r removing side2 main: remote created -> g getting main 1 files updated, 0 files merged, 2 files removed, 0 files unresolved $ ls a main