phases: rework the logic of _pushdiscoveryphase to bound complexity This rework the various graph traversal in _pushdiscoveryphase to keep the complexity in check. This is done though a couple of things: - first, limiting the space we have to explore, for example, if we are not in publishing push, we don't need to consider remote draft roots that are also draft locally, as there is nothing to be moved there. - avoid unbounded descendant computation, and use the faster "rev between" computation. This provide a massive boost to performance when exchanging with repository with a massive amount of draft, like mozilla-try: ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.command.push # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = default ## benchmark.variants.revs = any-1-extra-rev before: 20.346590 seconds after: 11.232059 seconds (-38.15%, -7.48 seconds) ## benchmark.variants.revs = any-100-extra-rev before: 24.752051 seconds after: 15.367412 seconds (-37.91%, -9.38 seconds) After this changes, the push operation is still quite too slow. Some of this can be attributed to general phases slowness (reading all the roots from disk for example) and other know slowness (not using persistent-nodemap, branchmap, tags, etc. We are also working on them, but with this series, phase discovery during push no longer showing up in profile and this is a pretty nice and bit low-hanging fruit out of the way. ### (same case as the above) # benchmark.variants.revs = any-1-extra-rev pre-%ln-change: 44.235070 this-changeset: 11.232059 seconds (-74.61%, -33.00 seconds) # benchmark.variants.revs = any-100-extra-rev pre-%ln-change: 49.234697 this-changeset: 15.367412 seconds (-68.79%, -33.87 seconds) Note that with this change, the `hg push` performance is now much closer to the `hg pull` performance, even it still lagging behind a bit. (and the overall performance are still too slow). ### data-env-vars.name = mozilla-try-2023-03-22-ds2-pnm # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.pulled-delta-reuse-policy = default # bin-env-vars.hg.flavor = rust ## benchmark.variants.revs = any-1-extra-rev hg.command.pull: 6.517450 hg.command.push: 11.219888 ## benchmark.variants.revs = any-100-extra-rev hg.command.pull: 10.160991 hg.command.push: 14.251107 ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.pulled-delta-reuse-policy = default ## bin-env-vars.hg.flavor = default ## benchmark.variants.revs = any-1-extra-rev hg.command.pull: 8.577772 hg.command.push: 11.232059 ## bin-env-vars.hg.flavor = default ## benchmark.variants.revs = any-100-extra-rev hg.command.pull: 13.152976 hg.command.push: 15.367412 ## bin-env-vars.hg.flavor = rust ## benchmark.variants.revs = any-1-extra-rev hg.command.pull: 8.731982 hg.command.push: 11.178751 ## bin-env-vars.hg.flavor = rust ## benchmark.variants.revs = any-100-extra-rev hg.command.pull: 13.184236 hg.command.push: 15.620843

     1

  $ cat >> $HGRCPATH <<EOF

     2

  > [extensions]

     3

  > rebase=

     4

  > 

     5

  > [phases]

     6

  > publish=False

     7

  > 

     8

  > [alias]

     9

  > tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"

    10

  > EOF

    11

    12

    13

  $ hg init a

    14

  $ cd a

    15

    16

  $ echo c1 > c1

    17

  $ hg ci -Am c1

    18

  adding c1

    19

    20

  $ echo c2 > c2

    21

  $ hg ci -Am c2

    22

  adding c2

    23

    24

  $ echo l1 > l1

    25

  $ hg ci -Am l1

    26

  adding l1

    27

    28

  $ hg up -q -C 1

    29

    30

  $ echo r1 > r1

    31

  $ hg ci -Am r1

    32

  adding r1

    33

  created new head

    34

    35

  $ echo r2 > r2

    36

  $ hg ci -Am r2

    37

  adding r2

    38

    39

  $ hg tglog

    40

  @  4: 225af64d03e6 'r2'

    41

  |

    42

  o  3: 8d0a8c99b309 'r1'

    43

  |

    44

  | o  2: 87c180a611f2 'l1'

    45

  |/

    46

  o  1: 56daeba07f4b 'c2'

    47

  |

    48

  o  0: e8faad3d03ff 'c1'

    49

    50

Rebase with no arguments - single revision in source branch:

    51

    52

  $ hg up -q -C 2

    53

    54

  $ hg rebase

    55

  rebasing 2:87c180a611f2 "l1"

    56

  saved backup bundle to $TESTTMP/a/.hg/strip-backup/87c180a611f2-a5be192d-rebase.hg

    57

    58

  $ hg tglog

    59

  @  4: b1152cc99655 'l1'

    60

  |

    61

  o  3: 225af64d03e6 'r2'

    62

  |

    63

  o  2: 8d0a8c99b309 'r1'

    64

  |

    65

  o  1: 56daeba07f4b 'c2'

    66

  |

    67

  o  0: e8faad3d03ff 'c1'

    68

    69

  $ cd ..

    70

    71

    72

  $ hg init b

    73

  $ cd b

    74

    75

  $ echo c1 > c1

    76

  $ hg ci -Am c1

    77

  adding c1

    78

    79

  $ echo c2 > c2

    80

  $ hg ci -Am c2

    81

  adding c2

    82

    83

  $ echo l1 > l1

    84

  $ hg ci -Am l1

    85

  adding l1

    86

    87

  $ echo l2 > l2

    88

  $ hg ci -Am l2

    89

  adding l2

    90

    91

  $ hg up -q -C 1

    92

    93

  $ echo r1 > r1

    94

  $ hg ci -Am r1

    95

  adding r1

    96

  created new head

    97

    98

  $ hg tglog

    99

  @  4: 8d0a8c99b309 'r1'

   100

  |

   101

  | o  3: 1ac923b736ef 'l2'

   102

  | |

   103

  | o  2: 87c180a611f2 'l1'

   104

  |/

   105

  o  1: 56daeba07f4b 'c2'

   106

  |

   107

  o  0: e8faad3d03ff 'c1'

   108

   109

Rebase with no arguments - single revision in target branch:

   110

   111

  $ hg up -q -C 3

   112

   113

  $ hg rebase

   114

  rebasing 2:87c180a611f2 "l1"

   115

  rebasing 3:1ac923b736ef "l2"

   116

  saved backup bundle to $TESTTMP/b/.hg/strip-backup/87c180a611f2-b980535c-rebase.hg

   117

   118

  $ hg tglog

   119

  @  4: 023181307ed0 'l2'

   120

  |

   121

  o  3: 913ab52b43b4 'l1'

   122

  |

   123

  o  2: 8d0a8c99b309 'r1'

   124

  |

   125

  o  1: 56daeba07f4b 'c2'

   126

  |

   127

  o  0: e8faad3d03ff 'c1'

   128

   129

   130

  $ cd ..