view tests/test-bundle2-multiple-changegroups.t @ 32697:19b9fc40cc51

revlog: skeleton support for version 2 revlogs

There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.

It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.

This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.

An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.

To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.

Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.

There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.

Create an extension to test bundle2 with multiple changegroups

  $ cat > bundle2.py <<EOF
  > """
  > """
  > from mercurial import changegroup, discovery, exchange
  > 
  > def _getbundlechangegrouppart(bundler, repo, source, bundlecaps=None,
  >                               b2caps=None, heads=None, common=None,
  >                               **kwargs):
  >     # Create two changegroups given the common changesets and heads for the
  >     # changegroup part we are being requested. Use the parent of each head
  >     # in 'heads' as intermediate heads for the first changegroup.
  >     intermediates = [repo[r].p1().node() for r in heads]
  >     outgoing = discovery.outgoing(repo, common, intermediates)
  >     cg = changegroup.getchangegroup(repo, source, outgoing,
  >                                     bundlecaps=bundlecaps)
  >     bundler.newpart('output', data='changegroup1')
  >     bundler.newpart('changegroup', data=cg.getchunks())
  >     outgoing = discovery.outgoing(repo, common + intermediates, heads)
  >     cg = changegroup.getchangegroup(repo, source, outgoing,
  >                                     bundlecaps=bundlecaps)
  >     bundler.newpart('output', data='changegroup2')
  >     bundler.newpart('changegroup', data=cg.getchunks())
  > 
  > def _pull(repo, *args, **kwargs):
  >   pullop = _orig_pull(repo, *args, **kwargs)
  >   repo.ui.write('pullop.cgresult is %d\n' % pullop.cgresult)
  >   return pullop
  > 
  > _orig_pull = exchange.pull
  > exchange.pull = _pull
  > exchange.getbundle2partsmapping['changegroup'] = _getbundlechangegrouppart
  > EOF

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate={rev}:{node|short} {phase} {author} {bookmarks} {desc|firstline}
  > EOF

Start with a simple repository with a single commit

  $ hg init repo
  $ cd repo
  $ cat > .hg/hgrc << EOF
  > [extensions]
  > bundle2=$TESTTMP/bundle2.py
  > EOF

  $ echo A > A
  $ hg commit -A -m A -q
  $ cd ..

Clone

  $ hg clone -q repo clone

Add two linear commits

  $ cd repo
  $ echo B > B
  $ hg commit -A -m B -q
  $ echo C > C
  $ hg commit -A -m C -q

  $ cd ../clone
  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > pretxnchangegroup = sh -c "printenv.py pretxnchangegroup"
  > changegroup = sh -c "printenv.py changegroup"
  > incoming = sh -c "printenv.py incoming"
  > EOF

Pull the new commits in the clone

  $ hg pull
  pulling from $TESTTMP/repo (glob)
  searching for changes
  remote: changegroup1
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  pretxnchangegroup hook: HG_HOOKNAME=pretxnchangegroup HG_HOOKTYPE=pretxnchangegroup HG_NODE=27547f69f25460a52fff66ad004e58da7ad3fb56 HG_NODE_LAST=27547f69f25460a52fff66ad004e58da7ad3fb56 HG_PENDING=$TESTTMP/clone HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  remote: changegroup2
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  pretxnchangegroup hook: HG_HOOKNAME=pretxnchangegroup HG_HOOKTYPE=pretxnchangegroup HG_NODE=f838bfaca5c7226600ebcfd84f3c3c13a28d3757 HG_NODE_LAST=f838bfaca5c7226600ebcfd84f3c3c13a28d3757 HG_PENDING=$TESTTMP/clone HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=27547f69f25460a52fff66ad004e58da7ad3fb56 HG_NODE_LAST=27547f69f25460a52fff66ad004e58da7ad3fb56 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=27547f69f25460a52fff66ad004e58da7ad3fb56 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=f838bfaca5c7226600ebcfd84f3c3c13a28d3757 HG_NODE_LAST=f838bfaca5c7226600ebcfd84f3c3c13a28d3757 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=f838bfaca5c7226600ebcfd84f3c3c13a28d3757 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  pullop.cgresult is 1
  (run 'hg update' to get a working copy)
  $ hg update
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G
  @  2:f838bfaca5c7 public test  C
  |
  o  1:27547f69f254 public test  B
  |
  o  0:4a2df7238c3b public test  A
  
Add more changesets with multiple heads to the original repository

  $ cd ../repo
  $ echo D > D
  $ hg commit -A -m D -q
  $ hg up -r 1
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo E > E
  $ hg commit -A -m E -q
  $ echo F > F
  $ hg commit -A -m F -q
  $ hg up -r 1
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo G > G
  $ hg commit -A -m G -q
  $ hg up -r 3
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo H > H
  $ hg commit -A -m H -q
  $ hg log -G
  @  7:5cd59d311f65 draft test  H
  |
  | o  6:1d14c3ce6ac0 draft test  G
  | |
  | | o  5:7f219660301f draft test  F
  | | |
  | | o  4:8a5212ebc852 draft test  E
  | |/
  o |  3:b3325c91a4d9 draft test  D
  | |
  o |  2:f838bfaca5c7 draft test  C
  |/
  o  1:27547f69f254 draft test  B
  |
  o  0:4a2df7238c3b draft test  A
  
New heads are reported during transfer and properly accounted for in
pullop.cgresult

  $ cd ../clone
  $ hg pull
  pulling from $TESTTMP/repo (glob)
  searching for changes
  remote: changegroup1
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  pretxnchangegroup hook: HG_HOOKNAME=pretxnchangegroup HG_HOOKTYPE=pretxnchangegroup HG_NODE=b3325c91a4d916bcc4cdc83ea3fe4ece46a42f6e HG_NODE_LAST=8a5212ebc8527f9fb821601504794e3eb11a1ed3 HG_PENDING=$TESTTMP/clone HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  remote: changegroup2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files (+1 heads)
  pretxnchangegroup hook: HG_HOOKNAME=pretxnchangegroup HG_HOOKTYPE=pretxnchangegroup HG_NODE=7f219660301fe4c8a116f714df5e769695cc2b46 HG_NODE_LAST=5cd59d311f6508b8e0ed28a266756c859419c9f1 HG_PENDING=$TESTTMP/clone HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=b3325c91a4d916bcc4cdc83ea3fe4ece46a42f6e HG_NODE_LAST=8a5212ebc8527f9fb821601504794e3eb11a1ed3 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=b3325c91a4d916bcc4cdc83ea3fe4ece46a42f6e HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=8a5212ebc8527f9fb821601504794e3eb11a1ed3 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=7f219660301fe4c8a116f714df5e769695cc2b46 HG_NODE_LAST=5cd59d311f6508b8e0ed28a266756c859419c9f1 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=7f219660301fe4c8a116f714df5e769695cc2b46 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=1d14c3ce6ac0582d2809220d33e8cd7a696e0156 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=5cd59d311f6508b8e0ed28a266756c859419c9f1 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  pullop.cgresult is 3
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg log -G
  o  7:5cd59d311f65 public test  H
  |
  | o  6:1d14c3ce6ac0 public test  G
  | |
  | | o  5:7f219660301f public test  F
  | | |
  | | o  4:8a5212ebc852 public test  E
  | |/
  o |  3:b3325c91a4d9 public test  D
  | |
  @ |  2:f838bfaca5c7 public test  C
  |/
  o  1:27547f69f254 public test  B
  |
  o  0:4a2df7238c3b public test  A
  
Removing a head from the original repository by merging it

  $ cd ../repo
  $ hg merge -r 6 -q
  $ hg commit -m Merge
  $ echo I > I
  $ hg commit -A -m H -q
  $ hg log -G
  @  9:9d18e5bd9ab0 draft test  H
  |
  o    8:71bd7b46de72 draft test  Merge
  |\
  | o  7:5cd59d311f65 draft test  H
  | |
  o |  6:1d14c3ce6ac0 draft test  G
  | |
  | | o  5:7f219660301f draft test  F
  | | |
  +---o  4:8a5212ebc852 draft test  E
  | |
  | o  3:b3325c91a4d9 draft test  D
  | |
  | o  2:f838bfaca5c7 draft test  C
  |/
  o  1:27547f69f254 draft test  B
  |
  o  0:4a2df7238c3b draft test  A
  
Removed heads are reported during transfer and properly accounted for in
pullop.cgresult

  $ cd ../clone
  $ hg pull
  pulling from $TESTTMP/repo (glob)
  searching for changes
  remote: changegroup1
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (-1 heads)
  pretxnchangegroup hook: HG_HOOKNAME=pretxnchangegroup HG_HOOKTYPE=pretxnchangegroup HG_NODE=71bd7b46de72e69a32455bf88d04757d542e6cf4 HG_NODE_LAST=71bd7b46de72e69a32455bf88d04757d542e6cf4 HG_PENDING=$TESTTMP/clone HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  remote: changegroup2
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  pretxnchangegroup hook: HG_HOOKNAME=pretxnchangegroup HG_HOOKTYPE=pretxnchangegroup HG_NODE=9d18e5bd9ab09337802595d49f1dad0c98df4d84 HG_NODE_LAST=9d18e5bd9ab09337802595d49f1dad0c98df4d84 HG_PENDING=$TESTTMP/clone HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=71bd7b46de72e69a32455bf88d04757d542e6cf4 HG_NODE_LAST=71bd7b46de72e69a32455bf88d04757d542e6cf4 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=71bd7b46de72e69a32455bf88d04757d542e6cf4 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  changegroup hook: HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=9d18e5bd9ab09337802595d49f1dad0c98df4d84 HG_NODE_LAST=9d18e5bd9ab09337802595d49f1dad0c98df4d84 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  incoming hook: HG_HOOKNAME=incoming HG_HOOKTYPE=incoming HG_NODE=9d18e5bd9ab09337802595d49f1dad0c98df4d84 HG_PHASES_MOVED=1 HG_SOURCE=pull HG_TXNID=TXN:$ID$ HG_URL=file:$TESTTMP/repo
  pullop.cgresult is -2
  (run 'hg update' to get a working copy)
  $ hg log -G
  o  9:9d18e5bd9ab0 public test  H
  |
  o    8:71bd7b46de72 public test  Merge
  |\
  | o  7:5cd59d311f65 public test  H
  | |
  o |  6:1d14c3ce6ac0 public test  G
  | |
  | | o  5:7f219660301f public test  F
  | | |
  +---o  4:8a5212ebc852 public test  E
  | |
  | o  3:b3325c91a4d9 public test  D
  | |
  | @  2:f838bfaca5c7 public test  C
  |/
  o  1:27547f69f254 public test  B
  |
  o  0:4a2df7238c3b public test  A