Mercurial > hg
view tests/test-blackbox.t @ 26375:3686fa2b8eee
windows: insert file positioning call between reads and writes
fopen() and fdopen() have a unique-to-Windows requirement that
transitions between read and write operations in files opened
in modes r+, w+, and a+ perform a file positioning call
(fsetpos, fseek, or rewind) in between. While the MSDN docs don't
say what will happen if this is not done, observations reveal
that Python raises an IOError with errno 0. Furthermore, I
/think/ this behavior isn't deterministic. But I can reproduce
it reliably with subsequent patches applied that open revlogs
in a+ mode and perform both reads and writes.
This patch introduces a proxy class for file handles opened
in r+, w+, and a+ mode on Windows. The class intercepts calls
and audits whether a file positioning function has been called
between read and write operations. If not, a dummy, no-op seek
to the current file position is performed. This appears to be
sufficient to "trick" Windows into allowing transitions between
read and writes without raising errors.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 27 Sep 2015 18:46:53 -0700 |
parents | e8f9dffca36f |
children | 949e8c626d19 |
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setup $ cat >> $HGRCPATH <<EOF > [extensions] > blackbox= > mock=$TESTDIR/mockblackbox.py > mq= > EOF $ hg init blackboxtest $ cd blackboxtest command, exit codes, and duration $ echo a > a $ hg add a $ hg blackbox 1970/01/01 00:00:00 bob (*)> add a (glob) 1970/01/01 00:00:00 bob (*)> add a exited 0 after * seconds (glob) incoming change tracking create two heads to verify that we only see one change in the log later $ hg commit -ma $ hg up null 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo b > b $ hg commit -Amb adding b created new head clone, commit, pull $ hg clone . ../blackboxtest2 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo c > c $ hg commit -Amc adding c $ cd ../blackboxtest2 $ hg pull pulling from $TESTTMP/blackboxtest (glob) 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 blackbox -l 5 1970/01/01 00:00:00 bob (*)> pull (glob) 1970/01/01 00:00:00 bob (*)> updated served branch cache in ?.???? seconds (glob) 1970/01/01 00:00:00 bob (*)> wrote served branch cache with 1 labels and 2 nodes (glob) 1970/01/01 00:00:00 bob (*)> 1 incoming changes - new heads: d02f48003e62 (glob) 1970/01/01 00:00:00 bob (*)> pull exited 0 after * seconds (glob) we must not cause a failure if we cannot write to the log $ hg rollback repository tip rolled back to revision 1 (undo pull) #if unix-permissions no-root $ chmod 000 .hg/blackbox.log $ hg --debug incoming warning: cannot write to blackbox.log: Permission denied comparing with $TESTTMP/blackboxtest (glob) query 1; heads searching for changes all local heads known remotely changeset: 2:d02f48003e62c24e2659d97d30f2a83abe5d5d51 tag: tip phase: draft parent: 1:6563da9dcf87b1949716e38ff3e3dfaa3198eb06 parent: -1:0000000000000000000000000000000000000000 manifest: 2:ab9d46b053ebf45b7996f2922b9893ff4b63d892 user: test date: Thu Jan 01 00:00:00 1970 +0000 files+: c extra: branch=default description: c #endif $ hg pull pulling from $TESTTMP/blackboxtest (glob) 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) a failure reading from the log is fine #if unix-permissions no-root $ hg blackbox -l 3 abort: Permission denied: $TESTTMP/blackboxtest2/.hg/blackbox.log [255] $ chmod 600 .hg/blackbox.log #endif backup bundles get logged $ touch d $ hg commit -Amd adding d created new head $ hg strip tip 0 files updated, 0 files merged, 1 files removed, 0 files unresolved saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/*-backup.hg (glob) $ hg blackbox -l 5 1970/01/01 00:00:00 bob (*)> strip tip (glob) 1970/01/01 00:00:00 bob (*)> saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/*-backup.hg (glob) 1970/01/01 00:00:00 bob (*)> updated base branch cache in ?.???? seconds (glob) 1970/01/01 00:00:00 bob (*)> wrote base branch cache with 1 labels and 2 nodes (glob) 1970/01/01 00:00:00 bob (*)> strip tip exited 0 after * seconds (glob) extension and python hooks - use the eol extension for a pythonhook $ echo '[extensions]' >> .hg/hgrc $ echo 'eol=' >> .hg/hgrc $ echo '[hooks]' >> .hg/hgrc $ echo 'update = echo hooked' >> .hg/hgrc $ hg update 1 files updated, 0 files merged, 0 files removed, 0 files unresolved hooked $ hg blackbox -l 5 1970/01/01 00:00:00 bob (*)> update (glob) 1970/01/01 00:00:00 bob (*)> writing .hg/cache/tags2-visible with 0 tags (glob) 1970/01/01 00:00:00 bob (*)> pythonhook-preupdate: hgext.eol.preupdate finished in * seconds (glob) 1970/01/01 00:00:00 bob (*)> exthook-update: echo hooked finished in * seconds (glob) 1970/01/01 00:00:00 bob (*)> update exited 0 after * seconds (glob) log rotation $ echo '[blackbox]' >> .hg/hgrc $ echo 'maxsize = 20 b' >> .hg/hgrc $ echo 'maxfiles = 3' >> .hg/hgrc $ hg status $ hg status $ hg status $ hg tip -q 2:d02f48003e62 $ ls .hg/blackbox.log* .hg/blackbox.log .hg/blackbox.log.1 .hg/blackbox.log.2 cleanup $ cd ..