tests/test-fetch.t

changegroup: compute seen files as changesets are added (issue4750)

Before this patch, addchangegroup() would walk the changelog and compute
the set of seen files between applying changesets and applying
manifests. When cloning large repositories such as mozilla-central,
this consumed a non-trivial amount of time. On my MBP, this walk takes
~10s. On a dainty EC2 instance, this was measured to take ~125s! On the
latter machine, this delay was enough for the Mercurial server to
disconnect the client, thinking it had timed out, thus causing a clone
to abort.

This patch enables the changelog to compute the set of changed files as
new revisions are added. By doing so, we:

* avoid a potentially heavy computation between changelog and manifest
  processing by spreading the computation across all changelog additions
* avoid extra reads from the changelog by operating on the data as it is
  added

The downside of this is that the add revision callback does result in
extra I/O. Before, we would perform a flush (and subsequent read to
construct the full revision) when new delta chains were created. For
changelogs, this is typically every 2-4 revisions. Using the callback
guarantees there will be a flush after every added revision *and* an
open + read of the changelog to obtain the full revision in order to
read the added files. So, this increases the frequency of these
operations by the average chain length. In the future, the revlog
should be smart enough to know how to read revisions that haven't been
flushed yet, thus eliminating this extra I/O.

On my MBP, the total CPU times for an `hg unbundle` with a local
mozilla-central gzip bundle containing 251,934 changesets and 211,065
files did not have a statistically significant change with this patch,
holding steady around 360s. So, the increased revlog flushing did not
have an effect.

With this patch, there is no longer a visible pause between applying
changeset and manifest data. Before, it sure felt like Mercurial was
lethargic making this transition. Now, the transition is nearly
instantaneous, giving the impression that Mercurial is faster. Of course,
eliminating this pause means that the potential for network disconnect due
to channel inactivity during the changelog walk is eliminated as well.
And that is the impetus behind this change.

#require serve

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "fetch=" >> $HGRCPATH

test fetch with default branches only

  $ hg init a
  $ echo a > a/a
  $ hg --cwd a commit -Ama
  adding a
  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone a c
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b > a/b
  $ hg --cwd a commit -Amb
  adding b
  $ hg --cwd a parents -q
  1:d2ae7f538514

should pull one change

  $ hg --cwd b fetch ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg --cwd b parents -q
  1:d2ae7f538514
  $ echo c > c/c
  $ hg --cwd c commit -Amc
  adding c
  $ hg clone c d
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone c e
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

We cannot use the default commit message if fetching from a local
repo, because the path of the repo will be included in the commit
message, making every commit appear different.
should merge c into a

  $ hg --cwd c fetch -d '0 0' -m 'automated merge' ../a
  pulling from ../a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  updating to 2:d2ae7f538514
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  merging with 1:d36c0562f908
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  new changeset 3:a323a0c43ec4 merges remote changes with local
  $ ls c
  a
  b
  c
  $ hg --cwd a serve -a localhost -p $HGPORT -d --pid-file=hg.pid
  $ cat a/hg.pid >> "$DAEMON_PIDS"

fetch over http, no auth
(this also tests that editor is invoked if '--edit' is specified)

  $ HGEDITOR=cat hg --cwd d fetch --edit http://localhost:$HGPORT/
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  updating to 2:d2ae7f538514
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  merging with 1:d36c0562f908
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  Automated merge with http://localhost:$HGPORT/
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch merge
  HG: branch 'default'
  HG: changed c
  new changeset 3:* merges remote changes with local (glob)
  $ hg --cwd d tip --template '{desc}\n'
  Automated merge with http://localhost:$HGPORT/
  $ hg --cwd d status --rev 'tip^1' --rev tip
  A c
  $ hg --cwd d status --rev 'tip^2' --rev tip
  A b

fetch over http with auth (should be hidden in desc)
(this also tests that editor is not invoked if '--edit' is not
specified, even though commit message is not specified explicitly)

  $ HGEDITOR=cat hg --cwd e fetch http://user:password@localhost:$HGPORT/
  pulling from http://user:***@localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  updating to 2:d2ae7f538514
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  merging with 1:d36c0562f908
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  new changeset 3:* merges remote changes with local (glob)
  $ hg --cwd e tip --template '{desc}\n'
  Automated merge with http://localhost:$HGPORT/
  $ hg clone a f
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone a g
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo f > f/f
  $ hg --cwd f ci -Amf
  adding f
  $ echo g > g/g
  $ hg --cwd g ci -Amg
  adding g
  $ hg clone -q f h
  $ hg clone -q g i

should merge f into g

  $ hg --cwd g fetch -d '0 0' --switch -m 'automated merge' ../f
  pulling from ../f
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging with 3:6343ca3eff20
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  new changeset 4:f7faa0b7d3c6 merges remote changes with local
  $ rm i/g

should abort, because i is modified

  $ hg --cwd i fetch ../h
  abort: uncommitted changes
  [255]

test fetch with named branches

  $ hg init nbase
  $ echo base > nbase/a
  $ hg -R nbase ci -Am base
  adding a
  $ hg -R nbase branch a
  marked working directory as branch a
  (branches are permanent and global, did you want a bookmark?)
  $ echo a > nbase/a
  $ hg -R nbase ci -m a
  $ hg -R nbase up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R nbase branch b
  marked working directory as branch b
  $ echo b > nbase/b
  $ hg -R nbase ci -Am b
  adding b

pull in change on foreign branch

  $ hg clone nbase n1
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone nbase n2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n1 up -C a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo aa > n1/a
  $ hg -R n1 ci -m a1
  $ hg -R n2 up -C b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n2 fetch -m 'merge' n1
  pulling from n1
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files

parent should be 2 (no automatic update)

  $ hg -R n2 parents --template '{rev}\n'
  2
  $ rm -fr n1 n2

pull in changes on both foreign and local branches

  $ hg clone nbase n1
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone nbase n2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n1 up -C a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo aa > n1/a
  $ hg -R n1 ci -m a1
  $ hg -R n1 up -C b
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo bb > n1/b
  $ hg -R n1 ci -m b1
  $ hg -R n2 up -C b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n2 fetch -m 'merge' n1
  pulling from n1
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

parent should be 4 (fast forward)

  $ hg -R n2 parents --template '{rev}\n'
  4
  $ rm -fr n1 n2

pull changes on foreign (2 new heads) and local (1 new head) branches
with a local change

  $ hg clone nbase n1
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone nbase n2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n1 up -C a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo a1 > n1/a
  $ hg -R n1 ci -m a1
  $ hg -R n1 up -C b
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo bb > n1/b
  $ hg -R n1 ci -m b1
  $ hg -R n1 up -C 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a2 > n1/a
  $ hg -R n1 ci -m a2
  created new head
  $ hg -R n2 up -C b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo change >> n2/c
  $ hg -R n2 ci -A -m local
  adding c
  $ hg -R n2 fetch -d '0 0' -m 'merge' n1
  pulling from n1
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files (+2 heads)
  updating to 5:3c4a837a864f
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  merging with 3:1267f84a9ea5
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  new changeset 7:2cf2a1261f21 merges remote changes with local

parent should be 7 (new merge changeset)

  $ hg -R n2 parents --template '{rev}\n'
  7
  $ rm -fr n1 n2

pull in changes on foreign (merge of local branch) and local (2 new
heads) with a local change

  $ hg clone nbase n1
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone nbase n2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n1 up -C a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R n1 merge b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg -R n1 ci -m merge
  $ hg -R n1 up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo c > n1/a
  $ hg -R n1 ci -m c
  $ hg -R n1 up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo cc > n1/a
  $ hg -R n1 ci -m cc
  created new head
  $ hg -R n2 up -C b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo change >> n2/b
  $ hg -R n2 ci -A -m local
  $ hg -R n2 fetch -m 'merge' n1
  pulling from n1
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 1 files (+2 heads)
  not merging with 1 other new branch heads (use "hg heads ." and "hg merge" to merge them)
  [1]

parent should be 3 (fetch did not merge anything)

  $ hg -R n2 parents --template '{rev}\n'
  3
  $ rm -fr n1 n2

pull in change on different branch than dirstate

  $ hg init n1
  $ echo a > n1/a
  $ hg -R n1 ci -Am initial
  adding a
  $ hg clone n1 n2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b > n1/a
  $ hg -R n1 ci -m next
  $ hg -R n2 branch topic
  marked working directory as branch topic
  (branches are permanent and global, did you want a bookmark?)
  $ hg -R n2 fetch -m merge n1
  abort: working directory not at branch tip
  (use "hg update" to check out branch tip)
  [255]

parent should be 0 (fetch did not update or merge anything)

  $ hg -R n2 parents --template '{rev}\n'
  0
  $ rm -fr n1 n2

test fetch with inactive branches

  $ hg init ib1
  $ echo a > ib1/a
  $ hg --cwd ib1 ci -Am base
  adding a
  $ hg --cwd ib1 branch second
  marked working directory as branch second
  (branches are permanent and global, did you want a bookmark?)
  $ echo b > ib1/b
  $ hg --cwd ib1 ci -Am onsecond
  adding b
  $ hg --cwd ib1 branch -f default
  marked working directory as branch default
  $ echo c > ib1/c
  $ hg --cwd ib1 ci -Am newdefault
  adding c
  created new head
  $ hg clone ib1 ib2
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

fetch should succeed

  $ hg --cwd ib2 fetch ../ib1
  pulling from ../ib1
  searching for changes
  no changes found
  $ rm -fr ib1 ib2

test issue1726

  $ hg init i1726r1
  $ echo a > i1726r1/a
  $ hg --cwd i1726r1 ci -Am base
  adding a
  $ hg clone i1726r1 i1726r2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b > i1726r1/a
  $ hg --cwd i1726r1 ci -m second
  $ echo c > i1726r2/a
  $ hg --cwd i1726r2 ci -m third
  $ HGMERGE=true hg --cwd i1726r2 fetch ../i1726r1
  pulling from ../i1726r1
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  updating to 2:7837755a2789
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging with 1:d1f0c6c48ebd
  merging a
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  new changeset 3:* merges remote changes with local (glob)
  $ hg --cwd i1726r2 heads default --template '{rev}\n'
  3

test issue2047

  $ hg -q init i2047a
  $ cd i2047a
  $ echo a > a
  $ hg -q ci -Am a
  $ hg -q branch stable
  $ echo b > b
  $ hg -q ci -Am b
  $ cd ..
  $ hg -q clone -r 0 i2047a i2047b
  $ cd i2047b
  $ hg fetch ../i2047a
  pulling from ../i2047a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files

  $ cd ..