view tests/test-rebase-collapse.t @ 16120:47ee41fcf42b

largefiles: optimize update speed by only updating changed largefiles

Historically, during 'hg update', every largefile in the working copy was
hashed (which is a very expensive operation on big files) and any
largefiles that did not have a hash that matched their standin were
updated.

This patch optimizes 'hg update' by keeping track of what standins have
changed between the old and new revisions, and only updating the largefiles
that have changed.  This saves a lot of time by avoiding the unecessary
calculation of a list of sha1 hashes for big files.

With this patch, the time 'hg update' takes to complete is a function of
how many largefiles need to be updated and what their size is.

Performance tests on a repository with about 80 largefiles ranging from
a few MB to about 97 MB are shown below.  The tests show how long it takes
to run 'hg update' with no changes actually being updated.

Mercurial 2.1 release:

$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
getting changed largefiles
0 largefiles updated, 0 removed

real    0m10.045s
user    0m9.367s
sys    0m0.674s

With this patch:

$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved

real    0m0.965s
user    0m0.845s
sys    0m0.115s

The same repsoitory, without the largefiles extension enabled:

$ time hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved

real    0m0.799s
user    0m0.684s
sys    0m0.111s

So before the patch, 'hg update' with no changes was approximately 9.25s
slower with largefiles enabled.  With this patch, it is approximately 0.165s
slower.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > graphlog=
  > rebase=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: '{desc}' {branches}\n"
  > tglogp = log -G --template "{rev}:{phase} '{desc}' {branches}\n"
  > EOF

Create repo a:

  $ hg init a
  $ cd a
  $ hg unbundle $TESTDIR/bundles/rebase.hg
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg tglog
  @  7: 'H'
  |
  | o  6: 'G'
  |/|
  o |  5: 'F'
  | |
  | o  4: 'E'
  |/
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebasing B onto H and collapsing changesets with different phases:


  $ hg clone -q -u 3 a a1
  $ cd a1

  $ hg phase --force --secret 3

  $ hg rebase --collapse --keepbranches
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/*-backup.hg (glob)

  $ hg tglogp
  @  5:secret 'Collapsed revision
  |  * B
  |  * C
  |  * D'
  o  4:draft 'H'
  |
  | o  3:draft 'G'
  |/|
  o |  2:draft 'F'
  | |
  | o  1:draft 'E'
  |/
  o  0:draft 'A'
  
  $ hg manifest
  A
  B
  C
  D
  F
  H

  $ cd ..


Rebasing E onto H:

  $ hg clone -q -u . a a2
  $ cd a2

  $ hg phase --force --secret 6
  $ hg rebase --source 4 --collapse
  saved backup bundle to $TESTTMP/a2/.hg/strip-backup/*-backup.hg (glob)

  $ hg tglog
  @  6: 'Collapsed revision
  |  * E
  |  * G'
  o  5: 'H'
  |
  o  4: 'F'
  |
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest
  A
  E
  F
  H

  $ cd ..

Rebasing G onto H with custom message:

  $ hg clone -q -u . a a3
  $ cd a3

  $ hg rebase --base 6 -m 'custom message'
  abort: message can only be specified with collapse
  [255]

  $ hg rebase --source 4 --collapse -m 'custom message'
  saved backup bundle to $TESTTMP/a3/.hg/strip-backup/*-backup.hg (glob)

  $ hg tglog
  @  6: 'custom message'
  |
  o  5: 'H'
  |
  o  4: 'F'
  |
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest
  A
  E
  F
  H

  $ cd ..

Create repo b:

  $ hg init b
  $ cd b

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B

  $ hg up -q 0

  $ echo C > C
  $ hg ci -Am C
  adding C
  created new head

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo D > D
  $ hg ci -Am D
  adding D

  $ hg up -q 1

  $ echo E > E
  $ hg ci -Am E
  adding E
  created new head

  $ echo F > F
  $ hg ci -Am F
  adding F

  $ hg merge
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m G

  $ hg up -q 0

  $ echo H > H
  $ hg ci -Am H
  adding H
  created new head

  $ hg tglog
  @  7: 'H'
  |
  | o    6: 'G'
  | |\
  | | o  5: 'F'
  | | |
  | | o  4: 'E'
  | | |
  | o |  3: 'D'
  | |\|
  | o |  2: 'C'
  |/ /
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase and collapse - more than one external (fail):

  $ hg clone -q -u . b b1
  $ cd b1

  $ hg rebase -s 2 --collapse
  abort: unable to collapse, there is more than one external parent
  [255]

Rebase and collapse - E onto H:

  $ hg rebase -s 4 --collapse
  saved backup bundle to $TESTTMP/b1/.hg/strip-backup/*-backup.hg (glob)

  $ hg tglog
  @    5: 'Collapsed revision
  |\   * E
  | |  * F
  | |  * G'
  | o  4: 'H'
  | |
  o |    3: 'D'
  |\ \
  | o |  2: 'C'
  | |/
  o /  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest
  A
  B
  C
  D
  E
  F
  H

  $ cd ..


Create repo c:

  $ hg init c
  $ cd c

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B

  $ hg up -q 0

  $ echo C > C
  $ hg ci -Am C
  adding C
  created new head

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo D > D
  $ hg ci -Am D
  adding D

  $ hg up -q 1

  $ echo E > E
  $ hg ci -Am E
  adding E
  created new head
  $ echo F > E
  $ hg ci -m 'F'

  $ echo G > G
  $ hg ci -Am G
  adding G

  $ hg merge
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg ci -m H

  $ hg up -q 0

  $ echo I > I
  $ hg ci -Am I
  adding I
  created new head

  $ hg tglog
  @  8: 'I'
  |
  | o    7: 'H'
  | |\
  | | o  6: 'G'
  | | |
  | | o  5: 'F'
  | | |
  | | o  4: 'E'
  | | |
  | o |  3: 'D'
  | |\|
  | o |  2: 'C'
  |/ /
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase and collapse - E onto I:

  $ hg clone -q -u . c c1
  $ cd c1

  $ hg rebase -s 4 --collapse
  merging E
  saved backup bundle to $TESTTMP/c1/.hg/strip-backup/*-backup.hg (glob)

  $ hg tglog
  @    5: 'Collapsed revision
  |\   * E
  | |  * F
  | |  * G
  | |  * H'
  | o  4: 'I'
  | |
  o |    3: 'D'
  |\ \
  | o |  2: 'C'
  | |/
  o /  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest
  A
  B
  C
  D
  E
  G
  I

  $ cat E
  F

  $ cd ..


Create repo d:

  $ hg init d
  $ cd d

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B
  $ echo C > C
  $ hg ci -Am C
  adding C

  $ hg up -q 1

  $ echo D > D
  $ hg ci -Am D
  adding D
  created new head
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg ci -m E

  $ hg up -q 0

  $ echo F > F
  $ hg ci -Am F
  adding F
  created new head

  $ hg tglog
  @  5: 'F'
  |
  | o    4: 'E'
  | |\
  | | o  3: 'D'
  | | |
  | o |  2: 'C'
  | |/
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase and collapse - B onto F:

  $ hg clone -q -u . d d1
  $ cd d1

  $ hg rebase -s 1 --collapse
  saved backup bundle to $TESTTMP/d1/.hg/strip-backup/*-backup.hg (glob)

  $ hg tglog
  @  2: 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |  * E'
  o  1: 'F'
  |
  o  0: 'A'
  
  $ hg manifest
  A
  B
  C
  D
  F

Interactions between collapse and keepbranches
  $ cd ..
  $ hg init e
  $ cd e
  $ echo 'a' > a
  $ hg ci -Am 'A'
  adding a

  $ hg branch '1'
  marked working directory as branch 1
  (branches are permanent and global, did you want a bookmark?)
  $ echo 'b' > b
  $ hg ci -Am 'B'
  adding b

  $ hg branch '2'
  marked working directory as branch 2
  (branches are permanent and global, did you want a bookmark?)
  $ echo 'c' > c
  $ hg ci -Am 'C'
  adding c

  $ hg up -q 0
  $ echo 'd' > d
  $ hg ci -Am 'D'
  adding d

  $ hg tglog
  @  3: 'D'
  |
  | o  2: 'C' 2
  | |
  | o  1: 'B' 1
  |/
  o  0: 'A'
  
  $ hg rebase --keepbranches --collapse -s 1 -d 3
  abort: cannot collapse multiple named branches
  [255]

  $ repeatchange() {
  >   hg checkout $1
  >   hg cp d z
  >   echo blah >> z
  >   hg commit -Am "$2" --user "$3"
  > }
  $ repeatchange 3 "E" "user1"
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ repeatchange 3 "E" "user2"
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  created new head
  $ hg tglog
  @  5: 'E'
  |
  | o  4: 'E'
  |/
  o  3: 'D'
  |
  | o  2: 'C' 2
  | |
  | o  1: 'B' 1
  |/
  o  0: 'A'
  
  $ hg rebase -s 5 -d 4
  saved backup bundle to $TESTTMP/e/.hg/strip-backup/*-backup.hg (glob)
  $ hg tglog
  @  4: 'E'
  |
  o  3: 'D'
  |
  | o  2: 'C' 2
  | |
  | o  1: 'B' 1
  |/
  o  0: 'A'
  
  $ hg export tip
  # HG changeset patch
  # User user1
  # Date 0 0
  # Node ID f338eb3c2c7cc5b5915676a2376ba7ac558c5213
  # Parent  41acb9dca9eb976e84cd21fcb756b4afa5a35c09
  E
  
  diff -r 41acb9dca9eb -r f338eb3c2c7c z
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/z	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,2 @@
  +d
  +blah