tests/test-uncommit.t

bundle2: implement consume() API on unbundlepart

We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.

A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.

In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.

The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:

! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)

Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.

Differential Revision: https://phab.mercurial-scm.org/D1388

Test uncommit - set up the config

  $ cat >> $HGRCPATH <<EOF
  > [experimental]
  > evolution.createmarkers=True
  > evolution.allowunstable=True
  > [extensions]
  > uncommit =
  > drawdag=$TESTDIR/drawdag.py
  > EOF

Build up a repo

  $ hg init repo
  $ cd repo
  $ hg bookmark foo

Help for uncommit

  $ hg help uncommit
  hg uncommit [OPTION]... [FILE]...
  
  uncommit part or all of a local changeset
  
      This command undoes the effect of a local commit, returning the affected
      files to their uncommitted state. This means that files modified or
      deleted in the changeset will be left unchanged, and so will remain
      modified in the working directory.
  
  (use 'hg help -e uncommit' to show help for the uncommit extension)
  
  options ([+] can be repeated):
  
      --keep                allow an empty commit after uncommiting
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
  
  (some details hidden, use --verbose to show complete help)

Uncommit with no commits should fail

  $ hg uncommit
  abort: cannot uncommit null changeset
  [255]

Create some commits

  $ touch files
  $ hg add files
  $ for i in a ab abc abcd abcde; do echo $i > files; echo $i > file-$i; hg add file-$i; hg commit -m "added file-$i"; done
  $ ls
  file-a
  file-ab
  file-abc
  file-abcd
  file-abcde
  files

  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  |
  o  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  |
  o  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  |
  o  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  
Simple uncommit off the top, also moves bookmark

  $ hg bookmark
   * foo                       4:6c4fd43ed714
  $ hg uncommit
  $ hg status
  M files
  A file-abcde
  $ hg bookmark
   * foo                       3:6db330d65db4

  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  x  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  |
  @  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  |
  o  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  |
  o  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  

Recommit

  $ hg commit -m 'new change abcde'
  $ hg status
  $ hg heads -T '{rev}:{node} {desc}'
  5:0c07a3ccda771b25f1cb1edbd02e683723344ef1 new change abcde (no-eol)

Uncommit of non-existent and unchanged files has no effect
  $ hg uncommit nothinghere
  nothing to uncommit
  [1]
  $ hg status
  $ hg uncommit file-abc
  nothing to uncommit
  [1]
  $ hg status

Try partial uncommit, also moves bookmark

  $ hg bookmark
   * foo                       5:0c07a3ccda77
  $ hg uncommit files
  $ hg status
  M files
  $ hg bookmark
   * foo                       6:3727deee06f7
  $ hg heads -T '{rev}:{node} {desc}'
  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcde (no-eol)
  $ hg log -r . -p -T '{rev}:{node} {desc}'
  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcdediff -r 6db330d65db4 -r 3727deee06f7 file-abcde
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file-abcde	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +abcde
  
  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcde
  |
  | x  5:0c07a3ccda771b25f1cb1edbd02e683723344ef1 new change abcde
  |/
  | x  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  |/
  o  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  |
  o  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  |
  o  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  
  $ hg commit -m 'update files for abcde'

Uncommit with dirty state

  $ echo "foo" >> files
  $ cat files
  abcde
  foo
  $ hg status
  M files
  $ hg uncommit
  abort: uncommitted changes
  [255]
  $ hg uncommit files
  $ cat files
  abcde
  foo
  $ hg commit -m "files abcde + foo"

Testing the 'experimental.uncommitondirtywdir' config

  $ echo "bar" >> files
  $ hg uncommit
  abort: uncommitted changes
  [255]
  $ hg uncommit --config experimental.uncommitondirtywdir=True
  $ hg commit -m "files abcde + foo"

Uncommit in the middle of a stack, does not move bookmark

  $ hg checkout '.^^^'
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  (leaving bookmark foo)
  $ hg log -r . -p -T '{rev}:{node} {desc}'
  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abcdiff -r 69a232e754b0 -r abf2df566fc1 file-abc
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file-abc	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +abc
  diff -r 69a232e754b0 -r abf2df566fc1 files
  --- a/files	Thu Jan 01 00:00:00 1970 +0000
  +++ b/files	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -ab
  +abc
  
  $ hg bookmark
     foo                       9:48e5bd7cd583
  $ hg uncommit
  $ hg status
  M files
  A file-abc
  $ hg heads -T '{rev}:{node} {desc}'
  9:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo (no-eol)
  $ hg bookmark
     foo                       9:48e5bd7cd583
  $ hg commit -m 'new abc'
  created new head

Partial uncommit in the middle, does not move bookmark

  $ hg checkout '.^'
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg log -r . -p -T '{rev}:{node} {desc}'
  1:69a232e754b08d568c4899475faf2eb44b857802 added file-abdiff -r 3004d2d9b508 -r 69a232e754b0 file-ab
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file-ab	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +ab
  diff -r 3004d2d9b508 -r 69a232e754b0 files
  --- a/files	Thu Jan 01 00:00:00 1970 +0000
  +++ b/files	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -a
  +ab
  
  $ hg bookmark
     foo                       9:48e5bd7cd583
  $ hg uncommit file-ab
  $ hg status
  A file-ab

  $ hg heads -T '{rev}:{node} {desc}\n'
  11:8eb87968f2edb7f27f27fe676316e179de65fff6 added file-ab
  10:5dc89ca4486f8a88716c5797fa9f498d13d7c2e1 new abc
  9:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo

  $ hg bookmark
     foo                       9:48e5bd7cd583
  $ hg commit -m 'update ab'
  $ hg status
  $ hg heads -T '{rev}:{node} {desc}\n'
  12:f21039c59242b085491bb58f591afc4ed1c04c09 update ab
  10:5dc89ca4486f8a88716c5797fa9f498d13d7c2e1 new abc
  9:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo

  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  12:f21039c59242b085491bb58f591afc4ed1c04c09 update ab
  |
  o  11:8eb87968f2edb7f27f27fe676316e179de65fff6 added file-ab
  |
  | o  10:5dc89ca4486f8a88716c5797fa9f498d13d7c2e1 new abc
  | |
  | | o  9:48e5bd7cd583eb24164ef8b89185819c84c96ed7 files abcde + foo
  | | |
  | | | x  8:83815831694b1271e9f207cb1b79b2b19275edcb files abcde + foo
  | | |/
  | | | x  7:0977fa602c2fd7d8427ed4e7ee15ea13b84c9173 update files for abcde
  | | |/
  | | o  6:3727deee06f72f5ffa8db792ee299cf39e3e190b new change abcde
  | | |
  | | | x  5:0c07a3ccda771b25f1cb1edbd02e683723344ef1 new change abcde
  | | |/
  | | | x  4:6c4fd43ed714e7fcd8adbaa7b16c953c2e985b60 added file-abcde
  | | |/
  | | o  3:6db330d65db434145c0b59d291853e9a84719b24 added file-abcd
  | | |
  | | x  2:abf2df566fc193b3ac34d946e63c1583e4d4732b added file-abc
  | |/
  | x  1:69a232e754b08d568c4899475faf2eb44b857802 added file-ab
  |/
  o  0:3004d2d9b50883c1538fc754a3aeb55f1b4084f6 added file-a
  
Uncommit with draft parent

  $ hg uncommit
  $ hg phase -r .
  11: draft
  $ hg commit -m 'update ab again'

Uncommit with public parent

  $ hg phase -p "::.^"
  $ hg uncommit
  $ hg phase -r .
  11: public

Partial uncommit with public parent

  $ echo xyz > xyz
  $ hg add xyz
  $ hg commit -m "update ab and add xyz"
  $ hg uncommit xyz
  $ hg status
  A xyz
  $ hg phase -r .
  15: draft
  $ hg phase -r ".^"
  11: public

Uncommit leaving an empty changeset

  $ cd $TESTTMP
  $ hg init repo1
  $ cd repo1
  $ hg debugdrawdag <<'EOS'
  > Q
  > |
  > P
  > EOS
  $ hg up Q -q
  $ hg uncommit --keep
  $ hg log -G -T '{desc} FILES: {files}'
  @  Q FILES:
  |
  | x  Q FILES: Q
  |/
  o  P FILES: P
  
  $ hg status
  A Q

  $ cd ..
  $ rm -rf repo1

Testing uncommit while merge

  $ hg init repo2
  $ cd repo2

Create some history

  $ touch a
  $ hg add a
  $ for i in 1 2 3; do echo $i > a; hg commit -m "a $i"; done
  $ hg checkout 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ touch b
  $ hg add b
  $ for i in 1 2 3; do echo $i > b; hg commit -m "b $i"; done
  created new head
  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @  5:2cd56cdde163ded2fbb16ba2f918c96046ab0bf2 b 3
  |
  o  4:c3a0d5bb3b15834ffd2ef9ef603e93ec65cf2037 b 2
  |
  o  3:49bb009ca26078726b8870f1edb29fae8f7618f5 b 1
  |
  | o  2:990982b7384266e691f1bc08ca36177adcd1c8a9 a 3
  | |
  | o  1:24d38e3cf160c7b6f5ffe82179332229886a6d34 a 2
  |/
  o  0:ea4e33293d4d274a2ba73150733c2612231f398c a 1
  

Add and expect uncommit to fail on both merge working dir and merge changeset

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

  $ hg uncommit
  abort: outstanding uncommitted merge
  [255]

  $ hg uncommit --config experimental.uncommitondirtywdir=True
  abort: cannot uncommit while merging
  [255]

  $ hg status
  M a
  $ hg commit -m 'merge a and b'

  $ hg uncommit
  abort: cannot uncommit merge changeset
  [255]

  $ hg status
  $ hg log -G -T '{rev}:{node} {desc}' --hidden
  @    6:c03b9c37bc67bf504d4912061cfb527b47a63c6e merge a and b
  |\
  | o  5:2cd56cdde163ded2fbb16ba2f918c96046ab0bf2 b 3
  | |
  | o  4:c3a0d5bb3b15834ffd2ef9ef603e93ec65cf2037 b 2
  | |
  | o  3:49bb009ca26078726b8870f1edb29fae8f7618f5 b 1
  | |
  o |  2:990982b7384266e691f1bc08ca36177adcd1c8a9 a 3
  | |
  o |  1:24d38e3cf160c7b6f5ffe82179332229886a6d34 a 2
  |/
  o  0:ea4e33293d4d274a2ba73150733c2612231f398c a 1