revlog: introduce a mandatory `_writing` context to update revlog content
Before this change, various revlog methods where managing the opening and
closing of the revlog files manually and passing the file descriptor alors the
call path. To simplify the tracking of the write operation by a future docket,
we need something more organised. As a result, we introduce a `revlog._writing`
context manager that will wrap each revlog update operation. The file
descriptor are kept in the existing `revlog._writinghandles` parameter that
was already used by the `addgroup` logic.
All this change is internal to the revlog only, the "public" interface is not
affected. The `addrevision` and `addgroup` logic are still responsible for
setup up this context. However this new context give us multiple benefits:
* all writer use a same, unified, logic,
* this context is programmatically enforced,
* each write "session" as a clearly identified start and end.
The post-pull sidedata update logic is still doing writing by end and will be
adjusted in a later changesets.
This change affect the concurrency checker test, because register the state of
the file in the transaction sooner in `addrevision` (about as early as what
`addgroup` would do), so the abort is rollbacking the other commit. I don't want
to weaken the current main logic.
Differential Revision: https://phab.mercurial-scm.org/D10605
#require serve
$ cat <<EOF >> $HGRCPATH
> [extensions]
> schemes=
>
> [schemes]
> l = http://localhost:$HGPORT/
> parts = http://{1}:$HGPORT/
> z = file:\$PWD/
> EOF
$ hg init test
$ cd test
$ echo a > a
$ hg ci -Am initial
adding a
invalid scheme
$ hg log -R z:z
abort: no '://' in scheme url 'z:z'
[255]
http scheme
$ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
$ hg incoming l://
comparing with l://
searching for changes
no changes found
[1]
check that {1} syntax works
$ hg incoming --debug parts://localhost
using http://localhost:$HGPORT/
sending capabilities command
comparing with parts://localhost/
query 1; heads
sending batch command
searching for changes
all remote heads known locally
no changes found
(sent 2 HTTP requests and * bytes; received * bytes in responses) (glob)
[1]
check that paths are expanded
$ PWD=`pwd` hg incoming z://
comparing with z://
searching for changes
no changes found
[1]
check that debugexpandscheme outputs the canonical form
$ hg debugexpandscheme bb://user/repo
https://bitbucket.org/user/repo
expanding an unknown scheme emits the input
$ hg debugexpandscheme foobar://this/that
foobar://this/that
expanding a canonical URL emits the input
$ hg debugexpandscheme https://bitbucket.org/user/repo
https://bitbucket.org/user/repo
errors
$ cat errors.log
$ cd ..