sqlitestore: support for storing revisions without their parents
This commit kinda/sorta implements the equivalent of ellipsis nodes for
the SQLite storage backend.
Without implementing full blown ellipsis nodes (and the necessary support for
them in the wire protocol), we instead teach the store to rewrite the p1 and
p2 nodes to nullid when the incoming parent isn't in the local store. This allows
servers to remain dumb and send the real parent and have the clients deal
with the missing parent problem.
This obviously isn't ideal because a benefit of ellipsis nodes is we can
insert a fake parent to ellide missing changesets. But neither solution is
ideal because it drops the original parent from storage. We could probably
teach the SQLite store to retain the original parent and handle missing
parents at read time. However, parent revisions are stored as integers and
it isn't trivial to store an "empty" revision in the store yet, which would
be necessary to represent the "missing" parent.
The store is somewhat intelligent in trying to remove the missing parents
metadata when the revision is re-added. But, revision numbers will be all
messed up in that case, so I'm not sure it is worth it. At some point we'll
likely want to remove the concept of revision numbers from the database and
have the store invent them at index generation time. Or even better, we can
do away with revision numbers from the file storage interface completely.
We'll get there eventually...
Differential Revision: https://phab.mercurial-scm.org/D5168
# Create server
$ hg init server
$ cd server
$ cat >> .hg/hgrc << EOF
> [extensions]
> extension=$TESTDIR/flagprocessorext.py
> EOF
$ cd ../
# Clone server and enable extensions
$ hg clone -q server client
$ cd client
$ cat >> .hg/hgrc << EOF
> [extensions]
> extension=$TESTDIR/flagprocessorext.py
> EOF
# Commit file that will trigger the noop extension
$ echo '[NOOP]' > noop
$ hg commit -Aqm "noop"
# Commit file that will trigger the base64 extension
$ echo '[BASE64]' > base64
$ hg commit -Aqm 'base64'
# Commit file that will trigger the gzip extension
$ echo '[GZIP]' > gzip
$ hg commit -Aqm 'gzip'
# Commit file that will trigger noop and base64
$ echo '[NOOP][BASE64]' > noop-base64
$ hg commit -Aqm 'noop+base64'
# Commit file that will trigger noop and gzip
$ echo '[NOOP][GZIP]' > noop-gzip
$ hg commit -Aqm 'noop+gzip'
# Commit file that will trigger base64 and gzip
$ echo '[BASE64][GZIP]' > base64-gzip
$ hg commit -Aqm 'base64+gzip'
# Commit file that will trigger base64, gzip and noop
$ echo '[BASE64][GZIP][NOOP]' > base64-gzip-noop
$ hg commit -Aqm 'base64+gzip+noop'
# TEST: ensure the revision data is consistent
$ hg cat noop
[NOOP]
$ hg debugdata noop 0
[NOOP]
$ hg cat -r . base64
[BASE64]
$ hg debugdata base64 0
W0JBU0U2NF0K (no-eol)
$ hg cat -r . gzip
[GZIP]
$ hg debugdata gzip 0
x\x9c\x8bv\x8f\xf2\x0c\x88\xe5\x02\x00\x08\xc8\x01\xfd (no-eol) (esc)
$ hg cat -r . noop-base64
[NOOP][BASE64]
$ hg debugdata noop-base64 0
W05PT1BdW0JBU0U2NF0K (no-eol)
$ hg cat -r . noop-gzip
[NOOP][GZIP]
$ hg debugdata noop-gzip 0
x\x9c\x8b\xf6\xf3\xf7\x0f\x88\x8dv\x8f\xf2\x0c\x88\xe5\x02\x00\x1dH\x03\xf1 (no-eol) (esc)
$ hg cat -r . base64-gzip
[BASE64][GZIP]
$ hg debugdata base64-gzip 0
eJyLdnIMdjUziY12j/IMiOUCACLBBDo= (no-eol)
$ hg cat -r . base64-gzip-noop
[BASE64][GZIP][NOOP]
$ hg debugdata base64-gzip-noop 0
eJyLdnIMdjUziY12j/IMiI328/cPiOUCAESjBi4= (no-eol)
# Push to the server
$ hg push
pushing to $TESTTMP/server
searching for changes
adding changesets
adding manifests
adding file changes
added 7 changesets with 7 changes to 7 files
Ensure the data got to the server OK
$ cd ../server
$ hg cat -r 6e48f4215d24 noop
[NOOP]
$ hg debugdata noop 0
[NOOP]
$ hg cat -r 6e48f4215d24 base64
[BASE64]
$ hg debugdata base64 0
W0JBU0U2NF0K (no-eol)
$ hg cat -r 6e48f4215d24 gzip
[GZIP]
$ hg debugdata gzip 0
x\x9c\x8bv\x8f\xf2\x0c\x88\xe5\x02\x00\x08\xc8\x01\xfd (no-eol) (esc)
$ hg cat -r 6e48f4215d24 noop-base64
[NOOP][BASE64]
$ hg debugdata noop-base64 0
W05PT1BdW0JBU0U2NF0K (no-eol)
$ hg cat -r 6e48f4215d24 noop-gzip
[NOOP][GZIP]
$ hg debugdata noop-gzip 0
x\x9c\x8b\xf6\xf3\xf7\x0f\x88\x8dv\x8f\xf2\x0c\x88\xe5\x02\x00\x1dH\x03\xf1 (no-eol) (esc)
$ hg cat -r 6e48f4215d24 base64-gzip
[BASE64][GZIP]
$ hg debugdata base64-gzip 0
eJyLdnIMdjUziY12j/IMiOUCACLBBDo= (no-eol)
$ hg cat -r 6e48f4215d24 base64-gzip-noop
[BASE64][GZIP][NOOP]
$ hg debugdata base64-gzip-noop 0
eJyLdnIMdjUziY12j/IMiI328/cPiOUCAESjBi4= (no-eol)
# Initialize new client (not cloning) and setup extension
$ cd ..
$ hg init client2
$ cd client2
$ cat >> .hg/hgrc << EOF
> [paths]
> default = $TESTTMP/server
> [extensions]
> extension=$TESTDIR/flagprocessorext.py
> EOF
# Pull from server and update to latest revision
$ hg pull default
pulling from $TESTTMP/server
requesting all changes
adding changesets
adding manifests
adding file changes
added 7 changesets with 7 changes to 7 files
new changesets 07b1b9442c5b:6e48f4215d24
(run 'hg update' to get a working copy)
$ hg update
7 files updated, 0 files merged, 0 files removed, 0 files unresolved
# TEST: ensure the revision data is consistent
$ hg cat noop
[NOOP]
$ hg debugdata noop 0
[NOOP]
$ hg cat -r . base64
[BASE64]
$ hg debugdata base64 0
W0JBU0U2NF0K (no-eol)
$ hg cat -r . gzip
[GZIP]
$ hg debugdata gzip 0
x\x9c\x8bv\x8f\xf2\x0c\x88\xe5\x02\x00\x08\xc8\x01\xfd (no-eol) (esc)
$ hg cat -r . noop-base64
[NOOP][BASE64]
$ hg debugdata noop-base64 0
W05PT1BdW0JBU0U2NF0K (no-eol)
$ hg cat -r . noop-gzip
[NOOP][GZIP]
$ hg debugdata noop-gzip 0
x\x9c\x8b\xf6\xf3\xf7\x0f\x88\x8dv\x8f\xf2\x0c\x88\xe5\x02\x00\x1dH\x03\xf1 (no-eol) (esc)
$ hg cat -r . base64-gzip
[BASE64][GZIP]
$ hg debugdata base64-gzip 0
eJyLdnIMdjUziY12j/IMiOUCACLBBDo= (no-eol)
$ hg cat -r . base64-gzip-noop
[BASE64][GZIP][NOOP]
$ hg debugdata base64-gzip-noop 0
eJyLdnIMdjUziY12j/IMiI328/cPiOUCAESjBi4= (no-eol)
# TEST: ensure a missing processor is handled
$ echo '[FAIL][BASE64][GZIP][NOOP]' > fail-base64-gzip-noop
$ hg commit -Aqm 'fail+base64+gzip+noop'
abort: missing processor for flag '0x1'!
[255]
$ rm fail-base64-gzip-noop
# TEST: ensure we cannot register several flag processors on the same flag
$ cat >> .hg/hgrc << EOF
> [extensions]
> extension=$TESTDIR/flagprocessorext.py
> duplicate=$TESTDIR/flagprocessorext.py
> EOF
$ hg debugrebuilddirstate
Traceback (most recent call last):
File "*/mercurial/extensions.py", line *, in _runextsetup (glob)
extsetup(ui)
File "*/tests/flagprocessorext.py", line *, in extsetup (glob)
validatehash,
File "*/mercurial/revlog.py", line *, in addflagprocessor (glob)
_insertflagprocessor(flag, processor, _flagprocessors)
File "*/mercurial/revlog.py", line *, in _insertflagprocessor (glob)
raise error.Abort(msg)
Abort: cannot register multiple processors on flag '0x8'.
*** failed to set up extension duplicate: cannot register multiple processors on flag '0x8'.
$ hg st 2>&1 | egrep 'cannot register multiple processors|flagprocessorext'
File "*/tests/flagprocessorext.py", line *, in extsetup (glob)
Abort: cannot register multiple processors on flag '0x8'.
*** failed to set up extension duplicate: cannot register multiple processors on flag '0x8'.
File "*/tests/flagprocessorext.py", line *, in b64decode (glob)
$ cd ..
# TEST: bundle repo
$ hg init bundletest
$ cd bundletest
$ cat >> .hg/hgrc << EOF
> [extensions]
> flagprocessor=$TESTDIR/flagprocessorext.py
> EOF
$ for i in 0 single two three 4; do
> echo '[BASE64]a-bit-longer-'$i > base64
> hg commit -m base64-$i -A base64
> done
$ hg update 2 -q
$ echo '[BASE64]a-bit-longer-branching' > base64
$ hg commit -q -m branching
#if repobundlerepo
$ hg bundle --base 1 bundle.hg
4 changesets found
$ hg --config extensions.strip= strip -r 2 --no-backup --force -q
$ hg -R bundle.hg log --stat -T '{rev} {desc}\n' base64
5 branching
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
4 base64-4
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
3 base64-three
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
2 base64-two
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
1 base64-single
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
0 base64-0
base64 | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
$ hg bundle -R bundle.hg --base 1 bundle-again.hg -q
$ hg -R bundle-again.hg log --stat -T '{rev} {desc}\n' base64
5 branching
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
4 base64-4
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
3 base64-three
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
2 base64-two
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
1 base64-single
base64 | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
0 base64-0
base64 | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
$ rm bundle.hg bundle-again.hg
#endif
# TEST: hg status
$ hg status
$ hg diff