Mercurial > hg
view tests/test-debugcommands.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 | 944749de6f3a |
children | 0438df737fb7 |
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$ hg init debugrevlog $ cd debugrevlog $ echo a > a $ hg ci -Am adda adding a $ hg debugrevlog -m format : 1 flags : inline revisions : 1 merges : 0 ( 0.00%) normal : 1 (100.00%) revisions : 1 full : 1 (100.00%) deltas : 0 ( 0.00%) revision size : 44 full : 44 (100.00%) deltas : 0 ( 0.00%) avg chain length : 0 max chain length : 0 compression ratio : 0 uncompressed data size (min/max/avg) : 43 / 43 / 43 full revision size (min/max/avg) : 44 / 44 / 44 delta size (min/max/avg) : 0 / 0 / 0 Test debugindex, with and without the --debug flag $ hg debugindex a rev offset length .... linkrev nodeid p1 p2 (re) 0 0 3 .... 0 b789fdd96dc2 000000000000 000000000000 (re) $ hg --debug debugindex a rev offset length .... linkrev nodeid p1 p2 (re) 0 0 3 .... 0 b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 (re) $ hg debugindex -f 1 a rev flag offset length size .... link p1 p2 nodeid (re) 0 0000 0 3 2 .... 0 -1 -1 b789fdd96dc2 (re) $ hg --debug debugindex -f 1 a rev flag offset length size .... link p1 p2 nodeid (re) 0 0000 0 3 2 .... 0 -1 -1 b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 (re) Test max chain len $ cat >> $HGRCPATH << EOF > [format] > maxchainlen=4 > EOF $ printf "This test checks if maxchainlen config value is respected also it can serve as basic test for debugrevlog -d <file>.\n" >> a $ hg ci -m a $ printf "b\n" >> a $ hg ci -m a $ printf "c\n" >> a $ hg ci -m a $ printf "d\n" >> a $ hg ci -m a $ printf "e\n" >> a $ hg ci -m a $ printf "f\n" >> a $ hg ci -m a $ printf 'g\n' >> a $ hg ci -m a $ printf 'h\n' >> a $ hg ci -m a $ hg debugrevlog -d a # rev p1rev p2rev start end deltastart base p1 p2 rawsize totalsize compression heads chainlen 0 -1 -1 0 ??? 0 0 0 0 ??? ???? ? 1 0 (glob) 1 0 -1 ??? ??? 0 0 0 0 ??? ???? ? 1 1 (glob) 2 1 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 2 (glob) 3 2 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 3 (glob) 4 3 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 4 (glob) 5 4 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 0 (glob) 6 5 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 1 (glob) 7 6 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 2 (glob) 8 7 -1 ??? ??? ??? ??? ??? 0 ??? ???? ? 1 3 (glob) $ cd .. Test internal debugstacktrace command $ cat > debugstacktrace.py << EOF > from mercurial.util import debugstacktrace, dst, sys > def f(): > dst('hello world') > def g(): > f() > debugstacktrace(skip=-5, f=sys.stdout) > g() > EOF $ python debugstacktrace.py hello world at: debugstacktrace.py:7 in * (glob) debugstacktrace.py:5 in g debugstacktrace.py:3 in f stacktrace at: debugstacktrace.py:7 *in * (glob) debugstacktrace.py:6 *in g (glob) */util.py:* in debugstacktrace (glob)