manifest: persist the manifestfulltext cache Reconstructing the manifest from the revlog takes time, so much so that there already is a LRU cache to avoid having to load a manifest multiple times. This patch persists that LRU cache in the .hg/cache directory, so we can re-use this cache across hg commands. Commit benchmark (run on Macos 10.13 on a 2017-model Macbook Pro with Core i7 2.9GHz and flash drive), testing without and with patch run 5 times, baseline is r2a227782e754: * committing to an existing file, against the mozilla-central repository. Baseline real time average 1.9692, with patch 1.3786. A new debugcommand "hg debugmanifestfulltextcache" lets you inspect the cache, clear it, or add specific manifest nodeids to it. When calling repo.updatecaches(), the manifest(s) for the working copy parents are added to the cache. The hg perfmanifest command has an additional --clear-disk switch to clear this cache when testing manifest loading performance. Using this command to test performance on the firefox repository for revision f947d902ed91, whose manifest has a delta chain length of 60540, we see: $ hg perfmanifest f947d902ed91 --clear-disk ! wall 0.972253 comb 0.970000 user 0.850000 sys 0.120000 (best of 10) $ hg debugmanifestfulltextcache -a `hg log --debug -r f947d902ed91 | grep manifest | cut -d: -f3` Cache contains 1 manifest entries, in order of most to least recent: id: 0294517df4aad07c70701db43bc7ff24c3ce7dbc, size 25.6 MB Total cache data size 25.6 MB, on-disk 0 bytes $ hg perfmanifest f947d902ed91 ! wall 0.036748 comb 0.040000 user 0.020000 sys 0.020000 (best of 100) Worst-case scenario: a manifest text loaded from a single delta; in the firefox repository manifest node 9a1246ff762e is the chain base for the manifest attached to revision f947d902ed91. Loading this from a full cache file is just as fast as without the cache; the extra node ids ensure a big full cache: $ for node in 9a1246ff762e 1a1922c14a3e 54a31d11a36a 0294517df4aa; do > hgd debugmanifestfulltextcache -a $node > /dev/null > done $ hgd perfmanifest -m 9a1246ff762e ! wall 0.077513 comb 0.080000 user 0.030000 sys 0.050000 (best of 100) $ hgd perfmanifest -m 9a1246ff762e --clear-disk ! wall 0.078547 comb 0.080000 user 0.070000 sys 0.010000 (best of 100)

     1

https://bz.mercurial-scm.org/1306

     2

     3

Initialize remote repo with branches:

     4

     5

  $ hg init remote

     6

  $ cd remote

     7

     8

  $ echo a > a

     9

  $ hg ci -Ama

    10

  adding a

    11

    12

  $ hg branch br

    13

  marked working directory as branch br

    14

  (branches are permanent and global, did you want a bookmark?)

    15

  $ hg ci -Amb

    16

    17

  $ echo c > c

    18

  $ hg ci -Amc

    19

  adding c

    20

    21

  $ hg log

    22

  changeset:   2:ae3d9c30ec50

    23

  branch:      br

    24

  tag:         tip

    25

  user:        test

    26

  date:        Thu Jan 01 00:00:00 1970 +0000

    27

  summary:     c

    28

    29

  changeset:   1:3f7f930ca414

    30

  branch:      br

    31

  user:        test

    32

  date:        Thu Jan 01 00:00:00 1970 +0000

    33

  summary:     b

    34

    35

  changeset:   0:cb9a9f314b8b

    36

  user:        test

    37

  date:        Thu Jan 01 00:00:00 1970 +0000

    38

  summary:     a

    39

    40

    41

  $ cd ..

    42

    43

Try cloning -r branch:

    44

    45

  $ hg clone -rbr remote local1

    46

  adding changesets

    47

  adding manifests

    48

  adding file changes

    49

  added 3 changesets with 2 changes to 2 files

    50

  new changesets cb9a9f314b8b:ae3d9c30ec50

    51

  updating to branch br

    52

  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

    53

    54

  $ hg -R local1 parents

    55

  changeset:   2:ae3d9c30ec50

    56

  branch:      br

    57

  tag:         tip

    58

  user:        test

    59

  date:        Thu Jan 01 00:00:00 1970 +0000

    60

  summary:     c

    61

    62

    63

Try cloning -rother clone#branch:

    64

    65

  $ hg clone -r0 remote#br local2

    66

  adding changesets

    67

  adding manifests

    68

  adding file changes

    69

  added 3 changesets with 2 changes to 2 files

    70

  new changesets cb9a9f314b8b:ae3d9c30ec50

    71

  updating to branch default

    72

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

    73

    74

  $ hg -R local2 parents

    75

  changeset:   0:cb9a9f314b8b

    76

  user:        test

    77

  date:        Thu Jan 01 00:00:00 1970 +0000

    78

  summary:     a

    79

    80

    81

Try cloning -r1 clone#branch:

    82

    83

  $ hg clone -r1 remote#br local3

    84

  adding changesets

    85

  adding manifests

    86

  adding file changes

    87

  added 3 changesets with 2 changes to 2 files

    88

  new changesets cb9a9f314b8b:ae3d9c30ec50

    89

  updating to branch br

    90

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

    91

    92

  $ hg -R local3 parents

    93

  changeset:   1:3f7f930ca414

    94

  branch:      br

    95

  user:        test

    96

  date:        Thu Jan 01 00:00:00 1970 +0000

    97

  summary:     b

    98

    99