wireprotov2: change how revisions are specified to changesetdata
Right now, we have a handful of arguments for specifying the revisions
whose data should be returned. Defining how all these arguments
interact when various combinations are present is difficult.
This commit establishes a new, generic mechanism for specifying
revisions. Instead of a hodgepodge of arguments defining things, we
have a list of dicts that specify revision selectors. The final set
of revisions is a union of all these selectors.
We implement support for specifying revisions based on:
* An explicit list of changeset revisions
* An explicit list of changeset revisions plus ancestry depth
* A DAG range between changeset roots and heads
If you squint hard enough, this problem has already been solved by
revsets. But I'm reluctant to expose revsets to the wire protocol
because that would require servers to implement a revset parser.
Plus there are security and performance implications: the set
of revision selectors needs to be narrowly and specifically tailored
for what is appropriate to be executing on a server. Perhaps there
would be a way for us to express the "parse tree" of a revset
query, for example. I'm not sure. We can explore this space another
time. For now, the new mechanism should bring sufficient flexibility
while remaining relatively simple.
The selector "types" are prefixed with "changeset" because I plan
to add manifest and file-flavored selectors as well. This will enable
us to e.g. select file revisions based on a range of changeset
revisions.
Differential Revision: https://phab.mercurial-scm.org/D4979
#require serve
$ hg init server
$ hg serve -R server -p $HGPORT -d --pid-file=hg1.pid -E ../error.log
$ cat hg1.pid >> $DAEMON_PIDS
Check basic fetching
$ hg debugdownload "http://localhost:$HGPORT/?cmd=lookup&key=tip"
1 0000000000000000000000000000000000000000
$ hg debugdownload -o null.txt "http://localhost:$HGPORT/?cmd=lookup&key=null"
$ cat null.txt
1 0000000000000000000000000000000000000000
Check the request is made from the usual Mercurial logic
(rev details, give different content if the request has a Mercurial user agent)
$ get-with-headers.py --headeronly "localhost:$HGPORT" "rev/tip" content-type
200 Script output follows
content-type: text/html; charset=ascii
$ hg debugdownload "http://localhost:$HGPORT/rev/tip"
# HG changeset patch
# User
# Date 0 0
# Node ID 0000000000000000000000000000000000000000
Check other kind of compatible url
$ hg debugdownload ./null.txt
1 0000000000000000000000000000000000000000
Test largefile URL
------------------
$ cat << EOF >> $HGRCPATH
> [extensions]
> largefiles=
> EOF
$ killdaemons.py
$ rm -f error.log hg1.pid
$ hg serve -R server -p $HGPORT -d --pid-file=hg1.pid -E error.log
$ cat hg1.pid >> $DAEMON_PIDS
$ hg -R server debuglfput null.txt
a57b57b39ee4dc3da1e03526596007f480ecdbe8
$ hg --traceback debugdownload "largefile://a57b57b39ee4dc3da1e03526596007f480ecdbe8" --config paths.default=http://localhost:$HGPORT/
1 0000000000000000000000000000000000000000
from within a repository
$ hg clone http://localhost:$HGPORT/ client
no changes found
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd client
$ hg path
default = http://localhost:$HGPORT/
$ hg debugdownload "largefile://a57b57b39ee4dc3da1e03526596007f480ecdbe8"
1 0000000000000000000000000000000000000000
$ cd ..