repository: define new interface for running commands
Today, the peer interface exposes methods for each command that can
be executed. In addition, there is an iterbatch() API that allows
commands to be issued in batches and provides an iterator over the
results. This is a glorified wrapper around the "batch" wire command.
Wire protocol version 2 supports nicer things (such as batching
any command and out-of-order replies). It will require a more
flexible API for executing commands.
This commit introduces a new peer interface for making command
requests. In the new world, you can't simply call a method on the
peer to execute a command: you need to obtain an object to be used
for executing commands. That object can be used to issue a single
command or it can batch multiple requests. In the case of full duplex
peers, the command may even be sent out over the wire immediately.
There are no per-command methods. Instead, there is a generic
method to call a command. The implementation can then perform domain
specific processing for specific commands. This includes passing
data via a specially named argument.
Arguments are also passed as a dictionary instead of using **kwargs.
While **kwargs is nicer to use, we've historically gotten into
trouble using it because there will inevitably be a conflict between
the name of an argument to a wire protocol command and an argument
we want to pass into a function.
Instead of a command returning a value, it returns a future which
will resolve to a value. This opens the door for out-of-order
response handling and concurrent response handling in the version
2 protocol.
Differential Revision: https://phab.mercurial-scm.org/D3267
setup repo
$ hg init t
$ cd t
$ echo a > a
$ hg commit -Am'add a'
adding a
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ hg parents
changeset: 0:1f0dee641bb7
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add a
rollback to null revision
$ hg status
$ hg rollback
repository tip rolled back to revision -1 (undo commit)
working directory now based on revision -1
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
0 files, 0 changesets, 0 total revisions
$ hg parents
$ hg status
A a
Two changesets this time so we rollback to a real changeset
$ hg commit -m'add a again'
$ echo a >> a
$ hg commit -m'modify a'
Test issue 902 (current branch is preserved)
$ hg branch test
marked working directory as branch test
(branches are permanent and global, did you want a bookmark?)
$ hg rollback
repository tip rolled back to revision 0 (undo commit)
working directory now based on revision 0
$ hg branch
default
Test issue 1635 (commit message saved)
$ cat .hg/last-message.txt ; echo
modify a
Test rollback of hg before issue 902 was fixed
$ hg commit -m "test3"
$ hg branch test
marked working directory as branch test
(branches are permanent and global, did you want a bookmark?)
$ rm .hg/undo.branch
$ hg rollback
repository tip rolled back to revision 0 (undo commit)
named branch could not be reset: current branch is still 'test'
working directory now based on revision 0
$ hg branch
test
working dir unaffected by rollback: do not restore dirstate et. al.
$ hg log --template '{rev} {branch} {desc|firstline}\n'
0 default add a again
$ hg status
M a
$ hg bookmark foo
$ hg commit -m'modify a again'
$ echo b > b
$ hg bookmark bar -r default #making bar active, before the transaction
$ hg commit -Am'add b'
adding b
$ hg log --template '{rev} {branch} {desc|firstline}\n'
2 test add b
1 test modify a again
0 default add a again
$ hg update bar
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
(activating bookmark bar)
$ cat .hg/undo.branch ; echo
test
$ hg rollback -f
repository tip rolled back to revision 1 (undo commit)
$ hg id -n
0
$ hg branch
default
$ cat .hg/bookmarks.current ; echo
bar
$ hg bookmark --delete foo bar
rollback by pretxncommit saves commit message (issue1635)
$ echo a >> a
$ hg --config hooks.pretxncommit=false commit -m"precious commit message"
transaction abort!
rollback completed
abort: pretxncommit hook exited with status * (glob)
[255]
$ cat .hg/last-message.txt ; echo
precious commit message
same thing, but run $EDITOR
$ cat > editor.sh << '__EOF__'
> echo "another precious commit message" > "$1"
> __EOF__
$ HGEDITOR="\"sh\" \"`pwd`/editor.sh\"" hg --config hooks.pretxncommit=false commit 2>&1
note: commit message saved in .hg/last-message.txt
transaction abort!
rollback completed
abort: pretxncommit hook exited with status * (glob)
[255]
$ cat .hg/last-message.txt
another precious commit message
test rollback on served repository
#if serve
$ hg commit -m "precious commit message"
$ hg serve -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
$ cd ..
$ hg clone http://localhost:$HGPORT u
requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 2 changes to 1 files (+1 heads)
new changesets 23b0221f3370:068774709090
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd u
$ hg id default
068774709090
now rollback and observe that 'hg serve' reloads the repository and
presents the correct tip changeset:
$ hg -R ../t rollback
repository tip rolled back to revision 1 (undo commit)
working directory now based on revision 0
$ hg id default
791dd2169706
$ killdaemons.py
#endif
update to older changeset and then refuse rollback, because
that would lose data (issue2998)
$ cd ../t
$ hg -q update
$ rm `hg status -un`
$ template='{rev}:{node|short} [{branch}] {desc|firstline}\n'
$ echo 'valuable new file' > b
$ echo 'valuable modification' >> a
$ hg commit -A -m'a valuable change'
adding b
$ hg update 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg rollback
abort: rollback of last commit while not checked out may lose data
(use -f to force)
[255]
$ hg tip -q
2:4d9cd3795eea
$ hg rollback -f
repository tip rolled back to revision 1 (undo commit)
$ hg status
$ hg log --removed b # yep, it's gone
same again, but emulate an old client that doesn't write undo.desc
$ hg -q update
$ echo 'valuable modification redux' >> a
$ hg commit -m'a valuable change redux'
$ rm .hg/undo.desc
$ hg update 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg rollback
rolling back unknown transaction
$ cat a
a
corrupt journal test
$ echo "foo" > .hg/store/journal
$ hg recover
rolling back interrupted transaction
couldn't read journal entry 'foo\n'!
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
rollback disabled by config
$ cat >> $HGRCPATH <<EOF
> [ui]
> rollback = false
> EOF
$ echo narf >> pinky-sayings.txt
$ hg add pinky-sayings.txt
$ hg ci -m 'First one.'
$ hg rollback
abort: rollback is disabled because it is unsafe
(see `hg help -v rollback` for information)
[255]
$ cd ..
I/O errors on stdio are handled properly (issue5658)
$ cat > badui.py << EOF
> import errno
> from mercurial.i18n import _
> from mercurial import (
> error,
> registrar,
> ui as uimod,
> )
>
> configtable = {}
> configitem = registrar.configitem(configtable)
>
> configitem(b'ui', b'ioerrors',
> default=list,
> )
>
> def pretxncommit(ui, repo, **kwargs):
> ui.warn(b'warn during pretxncommit\n')
>
> def pretxnclose(ui, repo, **kwargs):
> ui.warn(b'warn during pretxnclose\n')
>
> def txnclose(ui, repo, **kwargs):
> ui.warn(b'warn during txnclose\n')
>
> def txnabort(ui, repo, **kwargs):
> ui.warn(b'warn during abort\n')
>
> class fdproxy(object):
> def __init__(self, ui, o):
> self._ui = ui
> self._o = o
>
> def __getattr__(self, attr):
> return getattr(self._o, attr)
>
> def write(self, msg):
> errors = set(self._ui.configlist(b'ui', b'ioerrors'))
> pretxncommit = msg == b'warn during pretxncommit\n'
> pretxnclose = msg == b'warn during pretxnclose\n'
> txnclose = msg == b'warn during txnclose\n'
> txnabort = msg == b'warn during abort\n'
> msgabort = msg == _(b'transaction abort!\n')
> msgrollback = msg == _(b'rollback completed\n')
>
> if pretxncommit and b'pretxncommit' in errors:
> raise IOError(errno.EPIPE, 'simulated epipe')
> if pretxnclose and b'pretxnclose' in errors:
> raise IOError(errno.EIO, 'simulated eio')
> if txnclose and b'txnclose' in errors:
> raise IOError(errno.EBADF, 'simulated badf')
> if txnabort and b'txnabort' in errors:
> raise IOError(errno.EPIPE, 'simulated epipe')
> if msgabort and b'msgabort' in errors:
> raise IOError(errno.EBADF, 'simulated ebadf')
> if msgrollback and b'msgrollback' in errors:
> raise IOError(errno.EIO, 'simulated eio')
>
> return self._o.write(msg)
>
> def uisetup(ui):
> class badui(ui.__class__):
> def write_err(self, *args, **kwargs):
> olderr = self.ferr
> try:
> self.ferr = fdproxy(self, olderr)
> return super(badui, self).write_err(*args, **kwargs)
> finally:
> self.ferr = olderr
>
> ui.__class__ = badui
>
> def reposetup(ui, repo):
> ui.setconfig(b'hooks', b'pretxnclose.badui', pretxnclose, b'badui')
> ui.setconfig(b'hooks', b'txnclose.badui', txnclose, b'badui')
> ui.setconfig(b'hooks', b'pretxncommit.badui', pretxncommit, b'badui')
> ui.setconfig(b'hooks', b'txnabort.badui', txnabort, b'badui')
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> badui = $TESTTMP/badui.py
> EOF
An I/O error during pretxncommit is handled
$ hg init ioerror-pretxncommit
$ cd ioerror-pretxncommit
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=pretxncommit commit -m 'error during pretxncommit'
warn during pretxnclose
warn during txnclose
$ hg commit -m 'commit 1'
nothing changed
[1]
$ cd ..
An I/O error during pretxnclose is handled
$ hg init ioerror-pretxnclose
$ cd ioerror-pretxnclose
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=pretxnclose commit -m 'error during pretxnclose'
warn during pretxncommit
warn during txnclose
$ hg commit -m 'commit 1'
nothing changed
[1]
$ cd ..
An I/O error during txnclose is handled
$ hg init ioerror-txnclose
$ cd ioerror-txnclose
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=txnclose commit -m 'error during txnclose'
warn during pretxncommit
warn during pretxnclose
$ hg commit -m 'commit 1'
nothing changed
[1]
$ cd ..
An I/O error writing "transaction abort" is handled
$ hg init ioerror-msgabort
$ cd ioerror-msgabort
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=msgabort --config hooks.pretxncommit=false commit -m 'error during abort message'
warn during abort
rollback completed
abort: pretxncommit hook exited with status 1
[255]
$ hg commit -m 'commit 1'
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ cd ..
An I/O error during txnabort should still result in rollback
$ hg init ioerror-txnabort
$ cd ioerror-txnabort
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=txnabort --config hooks.pretxncommit=false commit -m 'error during abort'
transaction abort!
rollback completed
abort: pretxncommit hook exited with status 1
[255]
$ hg commit -m 'commit 1'
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ cd ..
An I/O error writing "rollback completed" is handled
$ hg init ioerror-msgrollback
$ cd ioerror-msgrollback
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=msgrollback --config hooks.pretxncommit=false commit -m 'error during rollback message'
transaction abort!
warn during abort
abort: pretxncommit hook exited with status 1
[255]
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ cd ..
Multiple I/O errors after transaction open are handled.
This is effectively what happens if a peer disconnects in the middle
of a transaction.
$ hg init ioerror-multiple
$ cd ioerror-multiple
$ echo 0 > foo
$ hg -q commit -A -m initial
warn during pretxncommit
warn during pretxnclose
warn during txnclose
$ echo 1 > foo
$ hg --config ui.ioerrors=pretxncommit,pretxnclose,txnclose,txnabort,msgabort,msgrollback commit -m 'multiple errors'
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
$ cd ..