dirstate-v2: Introduce a docket file
.hg/dirstate now only contains some metadata to point to a separate data file
named .hg/dirstate.{}.d with a random hexadecimal identifier. For now every
update creates a new data file and removes the old one, but later we’ll
(usually) append to an existing file.
Separating into two files allows doing the "write to a temporary file then
atomically rename into destination" dance with only a small docket file,
without always rewriting a lot of data.
Differential Revision: https://phab.mercurial-scm.org/D11088
Test that, when an hg push is interrupted and the remote side receives SIGPIPE,
the remote hg is able to successfully roll back the transaction.
$ hg init -q remote
$ hg clone -e "\"$PYTHON\" \"$RUNTESTDIR/dummyssh\"" -q ssh://user@dummy/`pwd`/remote local
$ SIGPIPE_REMOTE_DEBUG_FILE="$TESTTMP/DEBUGFILE"
$ SYNCFILE1="$TESTTMP/SYNCFILE1"
$ SYNCFILE2="$TESTTMP/SYNCFILE2"
$ export SIGPIPE_REMOTE_DEBUG_FILE
$ export SYNCFILE1
$ export SYNCFILE2
$ PYTHONUNBUFFERED=1
$ export PYTHONUNBUFFERED
On the remote end, run hg, piping stdout and stderr through processes that we
know the PIDs of. We will later kill these to simulate an ssh client
disconnecting.
$ remotecmd="$RUNTESTDIR/testlib/sigpipe-remote.py"
In the pretxnchangegroup hook, kill the PIDs recorded above to simulate ssh
disconnecting. Then exit nonzero, to force a transaction rollback.
$ cat >remote/.hg/hgrc <<EOF
> [hooks]
> pretxnchangegroup.00-break-things=sh "$RUNTESTDIR/testlib/wait-on-file" 10 "$SYNCFILE2" "$SYNCFILE1"
> pretxnchangegroup.01-output-things=echo "some remote output to be forward to the closed pipe"
> pretxnchangegroup.02-output-things=echo "some more remote output"
> EOF
$ hg --cwd ./remote tip -T '{node|short}\n'
000000000000
$ cd local
$ echo foo > foo ; hg commit -qAm "commit"
(use quiet to avoid flacky output from the server)
$ hg push --quiet -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" --remotecmd "$remotecmd"
abort: stream ended unexpectedly (got 0 bytes, expected 4)
[255]
$ cat $SIGPIPE_REMOTE_DEBUG_FILE
SIGPIPE-HELPER: Starting
SIGPIPE-HELPER: Redirection in place
SIGPIPE-HELPER: pipes closed in main
SIGPIPE-HELPER: SYNCFILE1 detected
SIGPIPE-HELPER: worker killed
SIGPIPE-HELPER: creating SYNCFILE2
SIGPIPE-HELPER: Shutting down
SIGPIPE-HELPER: Server process terminated with status 255 (no-windows !)
SIGPIPE-HELPER: Server process terminated with status 1 (windows !)
SIGPIPE-HELPER: Shut down
The remote should be left in a good state
$ hg --cwd ../remote tip -T '{node|short}\n'
000000000000
#if windows
XXX-Windows Broken behavior to be fixed
Behavior on Windows is broken and should be fixed. However this is a fairly
corner case situation and no data are being corrupted. This would affect
central repository being hosted on a Windows machine and accessed using ssh.
This was catch as we setup new CI for Windows. Making the test pass on Windows
was enough of a pain that fixing the behavior set aside for now. Dear and
honorable reader, feel free to fix it.
$ hg --cwd ../remote recover
rolling back interrupted transaction
(verify step skipped, run `hg verify` to check your repository content)
#else
$ hg --cwd ../remote recover
no interrupted transaction available
[1]
#endif