view tests/test-upgrade-repo.t @ 46149:294d5aca4ff5

copies: iterate over children directly (instead of parents)

Before this change we would gather all parent → child edges and iterate on
all parent, gathering copy information for children and aggregating them from
there.

They are not strict requirement for edges to be processed in that specific
order. We could also simply iterate over all "children" revision and aggregate
data from both parents at the same time. This patch does that.

It make various things simpler:

 * since both parents are processed at the same time, we no longer need to
   cache data for merge (see next changeset for details),

 * we no longer need nested loop to process data,

 * we no longer need to store partial merge data for a rev from distinct loop
   interaction to another when processing merges,

 * we no longer need to build a full parent -> children mapping (we only rely on
   a simpler "parent -> number of children" map (for memory efficiency),

 * the data access pattern is now simpler (from lower revisions to higher
   revisions) and entirely predicable. That predictability open the way to
   prefetching and parallel processing.

So that new iterations order requires simpler code and open the way to
interesting optimisation.

The effect on performance is quite good. In the worse case, we don't see any
significant negative impact. And in the best case, the reduction of roundtrip
to Python provide us with a significant speed. Some example below:

Repo            Case                                  Source-Rev   Dest-Rev      # of revisions  old time    new time      Difference    Factor    time per rev
---------------------------------------------------------------------------------------------------------------------------------------------------------------
mozilla-try     x00000_revs_x00000_added_0_copies     dc8a3ca7010e d16fde900c9c :  34414 revs,   0.962867 s,   0.502584 s,  -0.460283 s, × 0.5220,    14 µs/rev
mozilla-try     x0000_revs_xx000_added_x_copies       156f6e2674f2 4d0f2c178e66 :   8598 revs,   0.110717 s,   0.076323 s,  -0.034394 s, × 0.6894,     8 µs/rev



# full comparison between the previous changeset and this one

Repo            Case                                  Source-Rev   Dest-Rev      # of revisions  old time    new time      Difference    Factor    time per rev
---------------------------------------------------------------------------------------------------------------------------------------------------------------
mercurial       x_revs_x_added_0_copies               ad6b123de1c7 39cfcef4f463 :      1 revs,   0.000048 s,   0.000041 s,  -0.000007 s, × 0.8542,    41 µs/rev
mercurial       x_revs_x_added_x_copies               2b1c78674230 0c1d10351869 :      6 revs,   0.000153 s,   0.000102 s,  -0.000051 s, × 0.6667,    17 µs/rev
mercurial       x000_revs_x000_added_x_copies         81f8ff2a9bf2 dd3267698d84 :   1032 revs,   0.004209 s,   0.004254 s,  +0.000045 s, × 1.0107,     4 µs/rev
pypy            x_revs_x_added_0_copies               aed021ee8ae8 099ed31b181b :      9 revs,   0.000203 s,   0.000282 s,  +0.000079 s, × 1.3892,    31 µs/rev
pypy            x_revs_x000_added_0_copies            4aa4e1f8e19a 359343b9ac0e :      1 revs,   0.000059 s,   0.000048 s,  -0.000011 s, × 0.8136,    48 µs/rev
pypy            x_revs_x_added_x_copies               ac52eb7bbbb0 72e022663155 :      7 revs,   0.000194 s,   0.000211 s,  +0.000017 s, × 1.0876,    30 µs/rev
pypy            x_revs_x00_added_x_copies             c3b14617fbd7 ace7255d9a26 :      1 revs,   0.000380 s,   0.000375 s,  -0.000005 s, × 0.9868,   375 µs/rev
pypy            x_revs_x000_added_x000_copies         df6f7a526b60 a83dc6a2d56f :      6 revs,   0.010588 s,   0.010574 s,  -0.000014 s, × 0.9987,  1762 µs/rev
pypy            x000_revs_xx00_added_0_copies         89a76aede314 2f22446ff07e :   4785 revs,   0.048961 s,   0.049974 s,  +0.001013 s, × 1.0207,    10 µs/rev
pypy            x000_revs_x000_added_x_copies         8a3b5bfd266e 2c68e87c3efe :   6780 revs,   0.083612 s,   0.084300 s,  +0.000688 s, × 1.0082,    12 µs/rev
pypy            x000_revs_x000_added_x000_copies      89a76aede314 7b3dda341c84 :   5441 revs,   0.058579 s,   0.060128 s,  +0.001549 s, × 1.0264,    11 µs/rev
pypy            x0000_revs_x_added_0_copies           d1defd0dc478 c9cb1334cc78 :  43645 revs,   0.736783 s,   0.686542 s,  -0.050241 s, × 0.9318,    15 µs/rev
pypy            x0000_revs_xx000_added_0_copies       bf2c629d0071 4ffed77c095c :      2 revs,   0.022050 s,   0.009277 s,  -0.012773 s, × 0.4207,  4638 µs/rev
pypy            x0000_revs_xx000_added_x000_copies    08ea3258278e d9fa043f30c0 :  11316 revs,   0.120800 s,   0.114733 s,  -0.006067 s, × 0.9498,    10 µs/rev
netbeans        x_revs_x_added_0_copies               fb0955ffcbcd a01e9239f9e7 :      2 revs,   0.000140 s,   0.000081 s,  -0.000059 s, × 0.5786,    40 µs/rev
netbeans        x_revs_x000_added_0_copies            6f360122949f 20eb231cc7d0 :      2 revs,   0.000114 s,   0.000107 s,  -0.000007 s, × 0.9386,    53 µs/rev
netbeans        x_revs_x_added_x_copies               1ada3faf6fb6 5a39d12eecf4 :      3 revs,   0.000224 s,   0.000173 s,  -0.000051 s, × 0.7723,    57 µs/rev
netbeans        x_revs_x00_added_x_copies             35be93ba1e2c 9eec5e90c05f :      9 revs,   0.000723 s,   0.000698 s,  -0.000025 s, × 0.9654,    77 µs/rev
netbeans        x000_revs_xx00_added_0_copies         eac3045b4fdd 51d4ae7f1290 :   1421 revs,   0.009665 s,   0.009248 s,  -0.000417 s, × 0.9569,     6 µs/rev
netbeans        x000_revs_x000_added_x_copies         e2063d266acd 6081d72689dc :   1533 revs,   0.014820 s,   0.015446 s,  +0.000626 s, × 1.0422,    10 µs/rev
netbeans        x000_revs_x000_added_x000_copies      ff453e9fee32 411350406ec2 :   5750 revs,   0.076049 s,   0.074373 s,  -0.001676 s, × 0.9780,    12 µs/rev
netbeans        x0000_revs_xx000_added_x000_copies    588c2d1ced70 1aad62e59ddd :  66949 revs,   0.683603 s,   0.639870 s,  -0.043733 s, × 0.9360,     9 µs/rev
mozilla-central x_revs_x_added_0_copies               3697f962bb7b 7015fcdd43a2 :      2 revs,   0.000161 s,   0.000088 s,  -0.000073 s, × 0.5466,    44 µs/rev
mozilla-central x_revs_x000_added_0_copies            dd390860c6c9 40d0c5bed75d :      8 revs,   0.000234 s,   0.000199 s,  -0.000035 s, × 0.8504,    24 µs/rev
mozilla-central x_revs_x_added_x_copies               8d198483ae3b 14207ffc2b2f :      9 revs,   0.000247 s,   0.000171 s,  -0.000076 s, × 0.6923,    19 µs/rev
mozilla-central x_revs_x00_added_x_copies             98cbc58cc6bc 446a150332c3 :      7 revs,   0.000630 s,   0.000592 s,  -0.000038 s, × 0.9397,    84 µs/rev
mozilla-central x_revs_x000_added_x000_copies         3c684b4b8f68 0a5e72d1b479 :      3 revs,   0.003286 s,   0.003151 s,  -0.000135 s, × 0.9589,  1050 µs/rev
mozilla-central x_revs_x0000_added_x0000_copies       effb563bb7e5 c07a39dc4e80 :      6 revs,   0.062441 s,   0.061612 s,  -0.000829 s, × 0.9867, 10268 µs/rev
mozilla-central x000_revs_xx00_added_0_copies         6100d773079a 04a55431795e :   1593 revs,   0.005423 s,   0.005381 s,  -0.000042 s, × 0.9923,     3 µs/rev
mozilla-central x000_revs_x000_added_x_copies         9f17a6fc04f9 2d37b966abed :     41 revs,   0.005919 s,   0.003742 s,  -0.002177 s, × 0.6322,    91 µs/rev
mozilla-central x000_revs_x000_added_x000_copies      7c97034feb78 4407bd0c6330 :   7839 revs,   0.062597 s,   0.061983 s,  -0.000614 s, × 0.9902,     7 µs/rev
mozilla-central x0000_revs_xx000_added_0_copies       9eec5917337d 67118cc6dcad :    615 revs,   0.043551 s,   0.019861 s,  -0.023690 s, × 0.4560,    32 µs/rev
mozilla-central x0000_revs_xx000_added_x000_copies    f78c615a656c 96a38b690156 :  30263 revs,   0.192475 s,   0.188101 s,  -0.004374 s, × 0.9773,     6 µs/rev
mozilla-central x00000_revs_x0000_added_x0000_copies  6832ae71433c 4c222a1d9a00 : 153721 revs,   1.955575 s,   1.806696 s,  -0.148879 s, × 0.9239,    11 µs/rev
mozilla-central x00000_revs_x00000_added_x000_copies  76caed42cf7c 1daa622bbe42 : 204976 revs,   2.886501 s,   2.682987 s,  -0.203514 s, × 0.9295,    13 µs/rev
mozilla-try     x_revs_x_added_0_copies               aaf6dde0deb8 9790f499805a :      2 revs,   0.001181 s,   0.000852 s,  -0.000329 s, × 0.7214,   426 µs/rev
mozilla-try     x_revs_x000_added_0_copies            d8d0222927b4 5bb8ce8c7450 :      2 revs,   0.001189 s,   0.000859 s,  -0.000330 s, × 0.7225,   429 µs/rev
mozilla-try     x_revs_x_added_x_copies               092fcca11bdb 936255a0384a :      4 revs,   0.000563 s,   0.000150 s,  -0.000413 s, × 0.2664,    37 µs/rev
mozilla-try     x_revs_x00_added_x_copies             b53d2fadbdb5 017afae788ec :      2 revs,   0.001548 s,   0.001158 s,  -0.000390 s, × 0.7481,   579 µs/rev
mozilla-try     x_revs_x000_added_x000_copies         20408ad61ce5 6f0ee96e21ad :      1 revs,   0.027782 s,   0.027240 s,  -0.000542 s, × 0.9805, 27240 µs/rev
mozilla-try     x_revs_x0000_added_x0000_copies       effb563bb7e5 c07a39dc4e80 :      6 revs,   0.062781 s,   0.062824 s,  +0.000043 s, × 1.0007, 10470 µs/rev
mozilla-try     x000_revs_xx00_added_0_copies         6100d773079a 04a55431795e :   1593 revs,   0.005778 s,   0.005463 s,  -0.000315 s, × 0.9455,     3 µs/rev
mozilla-try     x000_revs_x000_added_x_copies         9f17a6fc04f9 2d37b966abed :     41 revs,   0.006192 s,   0.004238 s,  -0.001954 s, × 0.6844,   103 µs/rev
mozilla-try     x000_revs_x000_added_x000_copies      1346fd0130e4 4c65cbdabc1f :   6657 revs,   0.065391 s,   0.064113 s,  -0.001278 s, × 0.9805,     9 µs/rev
mozilla-try     x0000_revs_x_added_0_copies           63519bfd42ee a36a2a865d92 :  40314 revs,   0.317216 s,   0.294063 s,  -0.023153 s, × 0.9270,     7 µs/rev
mozilla-try     x0000_revs_x_added_x_copies           9fe69ff0762d bcabf2a78927 :  38690 revs,   0.303119 s,   0.281493 s,  -0.021626 s, × 0.9287,     7 µs/rev
mozilla-try     x0000_revs_xx000_added_x_copies       156f6e2674f2 4d0f2c178e66 :   8598 revs,   0.110717 s,   0.076323 s,  -0.034394 s, × 0.6894,     8 µs/rev
mozilla-try     x0000_revs_xx000_added_0_copies       9eec5917337d 67118cc6dcad :    615 revs,   0.045739 s,   0.020390 s,  -0.025349 s, × 0.4458,    33 µs/rev
mozilla-try     x0000_revs_xx000_added_x000_copies    89294cd501d9 7ccb2fc7ccb5 :  97052 revs,   3.098021 s,   3.023879 s,  -0.074142 s, × 0.9761,    31 µs/rev
mozilla-try     x0000_revs_x0000_added_x0000_copies   e928c65095ed e951f4ad123a :  52031 revs,   0.771480 s,   0.735549 s,  -0.035931 s, × 0.9534,    14 µs/rev
mozilla-try     x00000_revs_x_added_0_copies          6a320851d377 1ebb79acd503 : 363753 revs,  18.813422 s,  18.568900 s,  -0.244522 s, × 0.9870,    51 µs/rev
mozilla-try     x00000_revs_x00000_added_0_copies     dc8a3ca7010e d16fde900c9c :  34414 revs,   0.962867 s,   0.502584 s,  -0.460283 s, × 0.5220,    14 µs/rev
mozilla-try     x00000_revs_x_added_x_copies          5173c4b6f97c 95d83ee7242d : 362229 revs,  18.684923 s,  18.356645 s,  -0.328278 s, × 0.9824,    50 µs/rev
mozilla-try     x00000_revs_x000_added_x_copies       9126823d0e9c ca82787bb23c : 359344 revs,  18.296305 s,  18.250393 s,  -0.045912 s, × 0.9975,    50 µs/rev
mozilla-try     x00000_revs_x0000_added_x0000_copies  8d3fafa80d4b eb884023b810 : 192665 revs,   3.061887 s,   2.792459 s,  -0.269428 s, × 0.9120,    14 µs/rev
mozilla-try     x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 103.869641 s, 107.697264 s,  +3.827623 s, × 1.0369,   470 µs/rev
mozilla-try     x00000_revs_x00000_added_x000_copies  9b2a99adc05e 8e29777b48e6 : 382065 revs,  64.262957 s,  63.961040 s,  -0.301917 s, × 0.9953,   167 µs/rev

Differential Revision: https://phab.mercurial-scm.org/D9422

#require no-reposimplestore

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > share =
  > EOF

store and revlogv1 are required in source

  $ hg --config format.usestore=false init no-store
  $ hg -R no-store debugupgraderepo
  abort: cannot upgrade repository; requirement missing: store
  [255]

  $ hg init no-revlogv1
  $ cat > no-revlogv1/.hg/requires << EOF
  > dotencode
  > fncache
  > generaldelta
  > store
  > EOF

  $ hg -R no-revlogv1 debugupgraderepo
  abort: cannot upgrade repository; requirement missing: revlogv1
  [255]

Cannot upgrade shared repositories

  $ hg init share-parent
  $ hg -q share share-parent share-child

  $ hg -R share-child debugupgraderepo
  abort: cannot upgrade repository; unsupported source requirement: shared
  [255]

Do not yet support upgrading treemanifest repos

  $ hg --config experimental.treemanifest=true init treemanifest
  $ hg -R treemanifest debugupgraderepo
  abort: cannot upgrade repository; unsupported source requirement: treemanifest
  [255]

Cannot add treemanifest requirement during upgrade

  $ hg init disallowaddedreq
  $ hg -R disallowaddedreq --config experimental.treemanifest=true debugupgraderepo
  abort: cannot upgrade repository; do not support adding requirement: treemanifest
  [255]

An upgrade of a repository created with recommended settings only suggests optimizations

  $ hg init empty
  $ cd empty
  $ hg debugformat
  format-variant     repo
  fncache:            yes
  dotencode:          yes
  generaldelta:       yes
  exp-sharesafe:       no
  sparserevlog:       yes
  sidedata:            no
  persistent-nodemap:  no
  copies-sdc:          no
  plain-cl-delta:     yes
  compression:        zlib
  compression-level:  default
  $ hg debugformat --verbose
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib
  compression-level:  default default default
  $ hg debugformat --verbose --config format.usefncache=no
  format-variant     repo config default
  fncache:            yes     no     yes
  dotencode:          yes     no     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib
  compression-level:  default default default
  $ hg debugformat --verbose --config format.usefncache=no --color=debug
  format-variant     repo config default
  [formatvariant.name.mismatchconfig|fncache:           ][formatvariant.repo.mismatchconfig| yes][formatvariant.config.special|     no][formatvariant.default|     yes]
  [formatvariant.name.mismatchconfig|dotencode:         ][formatvariant.repo.mismatchconfig| yes][formatvariant.config.special|     no][formatvariant.default|     yes]
  [formatvariant.name.uptodate|generaldelta:      ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
  [formatvariant.name.uptodate|exp-sharesafe:     ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|sparserevlog:      ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
  [formatvariant.name.uptodate|sidedata:          ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|persistent-nodemap:][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|copies-sdc:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|plain-cl-delta:    ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
  [formatvariant.name.uptodate|compression:       ][formatvariant.repo.uptodate| zlib][formatvariant.config.default|   zlib][formatvariant.default|    zlib]
  [formatvariant.name.uptodate|compression-level: ][formatvariant.repo.uptodate| default][formatvariant.config.default| default][formatvariant.default| default]
  $ hg debugformat -Tjson
  [
   {
    "config": true,
    "default": true,
    "name": "fncache",
    "repo": true
   },
   {
    "config": true,
    "default": true,
    "name": "dotencode",
    "repo": true
   },
   {
    "config": true,
    "default": true,
    "name": "generaldelta",
    "repo": true
   },
   {
    "config": false,
    "default": false,
    "name": "exp-sharesafe",
    "repo": false
   },
   {
    "config": true,
    "default": true,
    "name": "sparserevlog",
    "repo": true
   },
   {
    "config": false,
    "default": false,
    "name": "sidedata",
    "repo": false
   },
   {
    "config": false,
    "default": false,
    "name": "persistent-nodemap",
    "repo": false
   },
   {
    "config": false,
    "default": false,
    "name": "copies-sdc",
    "repo": false
   },
   {
    "config": true,
    "default": true,
    "name": "plain-cl-delta",
    "repo": true
   },
   {
    "config": "zlib",
    "default": "zlib",
    "name": "compression",
    "repo": "zlib"
   },
   {
    "config": "default",
    "default": "default",
    "name": "compression-level",
    "repo": "default"
   }
  ]
  $ hg debugupgraderepo
  (no feature deficiencies found in existing repository)
  performing an upgrade with "--run" will make the following changes:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  additional optimizations are available by specifying "--optimize <name>":
  
  re-delta-parent
     deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
  
  re-delta-multibase
     deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
  
  re-delta-all
     deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
  
  re-delta-fulladd
     every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
  

  $ hg debugupgraderepo --quiet
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  

--optimize can be used to add optimizations

  $ hg debugupgrade --optimize redeltaparent
  (no feature deficiencies found in existing repository)
  performing an upgrade with "--run" will make the following changes:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  additional optimizations are available by specifying "--optimize <name>":
  
  re-delta-multibase
     deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
  
  re-delta-all
     deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
  
  re-delta-fulladd
     every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
  

modern form of the option

  $ hg debugupgrade --optimize re-delta-parent
  (no feature deficiencies found in existing repository)
  performing an upgrade with "--run" will make the following changes:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  additional optimizations are available by specifying "--optimize <name>":
  
  re-delta-multibase
     deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
  
  re-delta-all
     deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
  
  re-delta-fulladd
     every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
  
  $ hg debugupgrade --optimize re-delta-parent --quiet
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  

unknown optimization:

  $ hg debugupgrade --optimize foobar
  abort: unknown optimization action requested: foobar
  (run without arguments to see valid optimizations)
  [255]

Various sub-optimal detections work

  $ cat > .hg/requires << EOF
  > revlogv1
  > store
  > EOF

  $ hg debugformat
  format-variant     repo
  fncache:             no
  dotencode:           no
  generaldelta:        no
  exp-sharesafe:       no
  sparserevlog:        no
  sidedata:            no
  persistent-nodemap:  no
  copies-sdc:          no
  plain-cl-delta:     yes
  compression:        zlib
  compression-level:  default
  $ hg debugformat --verbose
  format-variant     repo config default
  fncache:             no    yes     yes
  dotencode:           no    yes     yes
  generaldelta:        no    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:        no    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib
  compression-level:  default default default
  $ hg debugformat --verbose --config format.usegeneraldelta=no
  format-variant     repo config default
  fncache:             no    yes     yes
  dotencode:           no    yes     yes
  generaldelta:        no     no     yes
  exp-sharesafe:       no     no      no
  sparserevlog:        no     no     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib
  compression-level:  default default default
  $ hg debugformat --verbose --config format.usegeneraldelta=no --color=debug
  format-variant     repo config default
  [formatvariant.name.mismatchconfig|fncache:           ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
  [formatvariant.name.mismatchconfig|dotencode:         ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
  [formatvariant.name.mismatchdefault|generaldelta:      ][formatvariant.repo.mismatchdefault|  no][formatvariant.config.special|     no][formatvariant.default|     yes]
  [formatvariant.name.uptodate|exp-sharesafe:     ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.mismatchdefault|sparserevlog:      ][formatvariant.repo.mismatchdefault|  no][formatvariant.config.special|     no][formatvariant.default|     yes]
  [formatvariant.name.uptodate|sidedata:          ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|persistent-nodemap:][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|copies-sdc:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
  [formatvariant.name.uptodate|plain-cl-delta:    ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
  [formatvariant.name.uptodate|compression:       ][formatvariant.repo.uptodate| zlib][formatvariant.config.default|   zlib][formatvariant.default|    zlib]
  [formatvariant.name.uptodate|compression-level: ][formatvariant.repo.uptodate| default][formatvariant.config.default| default][formatvariant.default| default]
  $ hg debugupgraderepo
  repository lacks features recommended by current config options:
  
  fncache
     long and reserved filenames may not work correctly; repository performance is sub-optimal
  
  dotencode
     storage of filenames beginning with a period or space may not work correctly
  
  generaldelta
     deltas within internal storage are unable to choose optimal revisions; repository is larger and slower than it could be; interaction with other repositories may require extra network and CPU resources, making "hg push" and "hg pull" slower
  
  sparserevlog
     in order to limit disk reading and memory usage on older version, the span of a delta chain from its root to its end is limited, whatever the relevant data in this span. This can severly limit Mercurial ability to build good chain of delta resulting is much more storage space being taken and limit reusability of on disk delta during exchange.
  
  
  performing an upgrade with "--run" will make the following changes:
  
  requirements
     preserved: revlogv1, store
     added: dotencode, fncache, generaldelta, sparserevlog
  
  fncache
     repository will be more resilient to storing certain paths and performance of certain operations should be improved
  
  dotencode
     repository will be better able to store files beginning with a space or period
  
  generaldelta
     repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
  
  sparserevlog
     Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  additional optimizations are available by specifying "--optimize <name>":
  
  re-delta-parent
     deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
  
  re-delta-multibase
     deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
  
  re-delta-all
     deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
  
  re-delta-fulladd
     every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
  
  $ hg debugupgraderepo --quiet
  requirements
     preserved: revlogv1, store
     added: dotencode, fncache, generaldelta, sparserevlog
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  

  $ hg --config format.dotencode=false debugupgraderepo
  repository lacks features recommended by current config options:
  
  fncache
     long and reserved filenames may not work correctly; repository performance is sub-optimal
  
  generaldelta
     deltas within internal storage are unable to choose optimal revisions; repository is larger and slower than it could be; interaction with other repositories may require extra network and CPU resources, making "hg push" and "hg pull" slower
  
  sparserevlog
     in order to limit disk reading and memory usage on older version, the span of a delta chain from its root to its end is limited, whatever the relevant data in this span. This can severly limit Mercurial ability to build good chain of delta resulting is much more storage space being taken and limit reusability of on disk delta during exchange.
  
  repository lacks features used by the default config options:
  
  dotencode
     storage of filenames beginning with a period or space may not work correctly
  
  
  performing an upgrade with "--run" will make the following changes:
  
  requirements
     preserved: revlogv1, store
     added: fncache, generaldelta, sparserevlog
  
  fncache
     repository will be more resilient to storing certain paths and performance of certain operations should be improved
  
  generaldelta
     repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
  
  sparserevlog
     Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  additional optimizations are available by specifying "--optimize <name>":
  
  re-delta-parent
     deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
  
  re-delta-multibase
     deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
  
  re-delta-all
     deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
  
  re-delta-fulladd
     every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
  

  $ cd ..

Upgrading a repository that is already modern essentially no-ops

  $ hg init modern
  $ hg -R modern debugupgraderepo --run
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/modern/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/modern/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/modern/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/modern/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified

Upgrading a repository to generaldelta works

  $ hg --config format.usegeneraldelta=false init upgradegd
  $ cd upgradegd
  $ touch f0
  $ hg -q commit -A -m initial
  $ mkdir FooBarDirectory.d
  $ touch FooBarDirectory.d/f1
  $ hg -q commit -A -m 'add f1'
  $ hg -q up -r 0
  >>> from __future__ import absolute_import, print_function
  >>> import random
  >>> random.seed(0) # have a reproducible content
  >>> with open("f2", "wb") as f:
  ...     for i in range(100000):
  ...         f.write(b"%d\n" % random.randint(1000000000, 9999999999)) and None
  $ hg -q commit -A -m 'add f2'

make sure we have a .d file

  $ ls -d .hg/store/data/*
  .hg/store/data/_foo_bar_directory.d.hg
  .hg/store/data/f0.i
  .hg/store/data/f2.d
  .hg/store/data/f2.i

  $ hg debugupgraderepo --run --config format.sparse-revlog=false
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, revlogv1, store
     added: generaldelta
  
  generaldelta
     repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (384 bytes in store; 238 bytes tracked data)
  finished migrating 3 manifest revisions across 1 manifests; change in size: -17 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: -17 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified

Original requirements backed up

  $ cat .hg/upgradebackup.*/requires
  dotencode
  fncache
  revlogv1
  store

generaldelta added to original requirements files

  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  store

store directory has files we expect

  $ ls .hg/store
  00changelog.i
  00manifest.i
  data
  fncache
  phaseroots
  undo
  undo.backupfiles
  undo.phaseroots

manifest should be generaldelta

  $ hg debugrevlog -m | grep flags
  flags  : inline, generaldelta

verify should be happy

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files

old store should be backed up

  $ ls -d .hg/upgradebackup.*/
  .hg/upgradebackup.*/ (glob)
  $ ls .hg/upgradebackup.*/store
  00changelog.i
  00manifest.i
  data
  fncache
  phaseroots
  undo
  undo.backup.fncache
  undo.backupfiles
  undo.phaseroots

unless --no-backup is passed

  $ rm -rf .hg/upgradebackup.*/
  $ hg debugupgraderepo --run --no-backup
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store
     added: sparserevlog
  
  sparserevlog
     Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for * (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  $ ls -1 .hg/ | grep upgradebackup
  [1]

We can restrict optimization to some revlog:

  $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  blindly copying data/FooBarDirectory.d/f1.i containing 1 revisions
  blindly copying data/f0.i containing 1 revisions
  blindly copying data/f2.i containing 1 revisions
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  cloning 3 revisions from 00manifest.i
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  blindly copying 00changelog.i containing 3 revisions
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)

Check that the repo still works fine

  $ hg log -G --stat
  @  changeset:   2:76d4395f5413 (no-py3 !)
  @  changeset:   2:fca376863211 (py3 !)
  |  tag:         tip
  |  parent:      0:ba592bf28da2
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     add f2
  |
  |   f2 |  100000 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  |   1 files changed, 100000 insertions(+), 0 deletions(-)
  |
  | o  changeset:   1:2029ce2354e2
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     add f1
  |
  |
  o  changeset:   0:ba592bf28da2
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     initial
  
  

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files

Check we can select negatively

  $ hg debugupgrade --optimize re-delta-parent --run --no-manifest --no-backup --debug --traceback
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - all-filelogs
    - changelog
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  cloning 1 revisions from data/FooBarDirectory.d/f1.i
  cloning 1 revisions from data/f0.i
  cloning 1 revisions from data/f2.i
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  blindly copying 00manifest.i containing 3 revisions
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  cloning 3 revisions from 00changelog.i
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files

Check that we can select changelog only

  $ hg debugupgrade --optimize re-delta-parent --run --changelog --no-backup --debug --traceback
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - changelog
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  blindly copying data/FooBarDirectory.d/f1.i containing 1 revisions
  blindly copying data/f0.i containing 1 revisions
  blindly copying data/f2.i containing 1 revisions
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  blindly copying 00manifest.i containing 3 revisions
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  cloning 3 revisions from 00changelog.i
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files

Check that we can select filelog only

  $ hg debugupgrade --optimize re-delta-parent --run --no-changelog --no-manifest --no-backup --debug --traceback
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - all-filelogs
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  cloning 1 revisions from data/FooBarDirectory.d/f1.i
  cloning 1 revisions from data/f0.i
  cloning 1 revisions from data/f2.i
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  blindly copying 00manifest.i containing 3 revisions
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  blindly copying 00changelog.i containing 3 revisions
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files


Check you can't skip revlog clone during important format downgrade

  $ echo "[format]" > .hg/hgrc
  $ echo "sparse-revlog=no" >> .hg/hgrc
  $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
  ignoring revlogs selection flags, format requirements change: sparserevlog
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store
     removed: sparserevlog
  
  optimisations: re-delta-parent
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  cloning 1 revisions from data/FooBarDirectory.d/f1.i
  cloning 1 revisions from data/f0.i
  cloning 1 revisions from data/f2.i
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  cloning 3 revisions from 00manifest.i
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  cloning 3 revisions from 00changelog.i
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files

Check you can't skip revlog clone during important format upgrade

  $ echo "sparse-revlog=yes" >> .hg/hgrc
  $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
  ignoring revlogs selection flags, format requirements change: sparserevlog
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store
     added: sparserevlog
  
  optimisations: re-delta-parent
  
  sparserevlog
     Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
  
  re-delta-parent
     deltas within internal storage will choose a new base revision if needed
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 519 KB in store; 1.05 MB tracked data
  migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
  cloning 1 revisions from data/FooBarDirectory.d/f1.i
  cloning 1 revisions from data/f0.i
  cloning 1 revisions from data/f2.i
  finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
  cloning 3 revisions from 00manifest.i
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
  cloning 3 revisions from 00changelog.i
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing old repository content$TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
  removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 3 files

  $ cd ..

store files with special filenames aren't encoded during copy

  $ hg init store-filenames
  $ cd store-filenames
  $ touch foo
  $ hg -q commit -A -m initial
  $ touch .hg/store/.XX_special_filename

  $ hg debugupgraderepo --run
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/store-filenames/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 3 total revisions (1 in filelogs, 1 in manifests, 1 in changelog)
  migrating 301 bytes in store; 107 bytes tracked data
  migrating 1 filelogs containing 1 revisions (64 bytes in store; 0 bytes tracked data)
  finished migrating 1 filelog revisions across 1 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 1 revisions (110 bytes in store; 45 bytes tracked data)
  finished migrating 1 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 1 revisions (127 bytes in store; 62 bytes tracked data)
  finished migrating 1 changelog revisions; change in size: 0 bytes
  finished migrating 3 total revisions; total change in store size: 0 bytes
  copying .XX_special_filename
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/store-filenames/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
  $ hg debugupgraderepo --run --optimize redeltafulladd
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-fulladd
  
  re-delta-fulladd
     each revision will be added as new content to the internal storage; this will likely drastically slow down execution time, but some extensions might need it
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/store-filenames/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 3 total revisions (1 in filelogs, 1 in manifests, 1 in changelog)
  migrating 301 bytes in store; 107 bytes tracked data
  migrating 1 filelogs containing 1 revisions (64 bytes in store; 0 bytes tracked data)
  finished migrating 1 filelog revisions across 1 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 1 revisions (110 bytes in store; 45 bytes tracked data)
  finished migrating 1 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 1 revisions (127 bytes in store; 62 bytes tracked data)
  finished migrating 1 changelog revisions; change in size: 0 bytes
  finished migrating 3 total revisions; total change in store size: 0 bytes
  copying .XX_special_filename
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/store-filenames/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified

fncache is valid after upgrade

  $ hg debugrebuildfncache
  fncache already up to date

  $ cd ..

Check upgrading a large file repository
---------------------------------------

  $ hg init largefilesrepo
  $ cat << EOF >> largefilesrepo/.hg/hgrc
  > [extensions]
  > largefiles =
  > EOF

  $ cd largefilesrepo
  $ touch foo
  $ hg add --large foo
  $ hg -q commit -m initial
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  largefiles
  revlogv1
  sparserevlog
  store

  $ hg debugupgraderepo --run
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, largefiles, revlogv1, sparserevlog, store
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/largefilesrepo/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 3 total revisions (1 in filelogs, 1 in manifests, 1 in changelog)
  migrating 355 bytes in store; 160 bytes tracked data
  migrating 1 filelogs containing 1 revisions (106 bytes in store; 41 bytes tracked data)
  finished migrating 1 filelog revisions across 1 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 1 revisions (116 bytes in store; 51 bytes tracked data)
  finished migrating 1 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 1 revisions (133 bytes in store; 68 bytes tracked data)
  finished migrating 1 changelog revisions; change in size: 0 bytes
  finished migrating 3 total revisions; total change in store size: 0 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/largefilesrepo/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/largefilesrepo/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/largefilesrepo/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  largefiles
  revlogv1
  sparserevlog
  store

  $ cat << EOF >> .hg/hgrc
  > [extensions]
  > lfs =
  > [lfs]
  > threshold = 10
  > EOF
  $ echo '123456789012345' > lfs.bin
  $ hg ci -Am 'lfs.bin'
  adding lfs.bin
  $ grep lfs .hg/requires
  lfs
  $ find .hg/store/lfs -type f
  .hg/store/lfs/objects/d0/beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f

  $ hg debugupgraderepo --run
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, largefiles, lfs, revlogv1, sparserevlog, store
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/largefilesrepo/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 6 total revisions (2 in filelogs, 2 in manifests, 2 in changelog)
  migrating 801 bytes in store; 467 bytes tracked data
  migrating 2 filelogs containing 2 revisions (296 bytes in store; 182 bytes tracked data)
  finished migrating 2 filelog revisions across 2 filelogs; change in size: 0 bytes
  migrating 1 manifests containing 2 revisions (241 bytes in store; 151 bytes tracked data)
  finished migrating 2 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 2 revisions (264 bytes in store; 134 bytes tracked data)
  finished migrating 2 changelog revisions; change in size: 0 bytes
  finished migrating 6 total revisions; total change in store size: 0 bytes
  copying phaseroots
  copying lfs blob d0beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/largefilesrepo/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/largefilesrepo/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/largefilesrepo/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified

  $ grep lfs .hg/requires
  lfs
  $ find .hg/store/lfs -type f
  .hg/store/lfs/objects/d0/beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 2 changes to 2 files
  $ hg debugdata lfs.bin 0
  version https://git-lfs.github.com/spec/v1
  oid sha256:d0beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
  size 16
  x-is-binary 0

  $ cd ..

repository config is taken in account
-------------------------------------

  $ cat << EOF >> $HGRCPATH
  > [format]
  > maxchainlen = 1
  > EOF

  $ hg init localconfig
  $ cd localconfig
  $ cat << EOF > file
  > some content
  > with some length
  > to make sure we get a delta
  > after changes
  > very long
  > very long
  > very long
  > very long
  > very long
  > very long
  > very long
  > very long
  > very long
  > very long
  > very long
  > EOF
  $ hg -q commit -A -m A
  $ echo "new line" >> file
  $ hg -q commit -m B
  $ echo "new line" >> file
  $ hg -q commit -m C

  $ cat << EOF >> .hg/hgrc
  > [format]
  > maxchainlen = 9001
  > EOF
  $ hg config format
  format.maxchainlen=9001
  $ hg debugdeltachain file
      rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio   readsize largestblk rddensity srchunks
        0       1        1       -1    base         77        182         77   0.42308        77         0    0.00000         77         77   1.00000        1
        1       1        2        0      p1         21        191         98   0.51309        98         0    0.00000         98         98   1.00000        1
        2       1        2        0   other         30        200        107   0.53500       128        21    0.19626        128        128   0.83594        1

  $ hg debugupgraderepo --run --optimize redeltaall
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
  
  optimisations: re-delta-all
  
  re-delta-all
     deltas within internal storage will be fully recomputed; this will likely drastically slow down execution time
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  beginning upgrade...
  repository locked and read-only
  creating temporary repository to stage migrated data: $TESTTMP/localconfig/.hg/upgrade.* (glob)
  (it is safe to interrupt this process any time before data migration completes)
  migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
  migrating 1019 bytes in store; 882 bytes tracked data
  migrating 1 filelogs containing 3 revisions (320 bytes in store; 573 bytes tracked data)
  finished migrating 3 filelog revisions across 1 filelogs; change in size: -9 bytes
  migrating 1 manifests containing 3 revisions (333 bytes in store; 138 bytes tracked data)
  finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
  migrating changelog containing 3 revisions (366 bytes in store; 171 bytes tracked data)
  finished migrating 3 changelog revisions; change in size: 0 bytes
  finished migrating 9 total revisions; total change in store size: -9 bytes
  copying phaseroots
  data fully migrated to temporary repository
  marking source repository as being upgraded; clients will be unable to read from repository
  starting in-place swap of repository data
  replaced files will be backed up at $TESTTMP/localconfig/.hg/upgradebackup.* (glob)
  replacing store...
  store replacement complete; repository was inconsistent for *s (glob)
  finalizing requirements file and making repository readable again
  removing temporary repository $TESTTMP/localconfig/.hg/upgrade.* (glob)
  copy of old repository backed up at $TESTTMP/localconfig/.hg/upgradebackup.* (glob)
  the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
  $ hg debugdeltachain file
      rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio   readsize largestblk rddensity srchunks
        0       1        1       -1    base         77        182         77   0.42308        77         0    0.00000         77         77   1.00000        1
        1       1        2        0      p1         21        191         98   0.51309        98         0    0.00000         98         98   1.00000        1
        2       1        3        1      p1         21        200        119   0.59500       119         0    0.00000        119        119   1.00000        1
  $ cd ..

  $ cat << EOF >> $HGRCPATH
  > [format]
  > maxchainlen = 9001
  > EOF

Check upgrading a sparse-revlog repository
---------------------------------------

  $ hg init sparserevlogrepo --config format.sparse-revlog=no
  $ cd sparserevlogrepo
  $ touch foo
  $ hg add foo
  $ hg -q commit -m "foo"
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  store

Check that we can add the sparse-revlog format requirement
  $ hg --config format.sparse-revlog=yes debugupgraderepo --run --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store
     added: sparserevlog
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store

Check that we can remove the sparse-revlog format requirement
  $ hg --config format.sparse-revlog=no debugupgraderepo --run --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store
     removed: sparserevlog
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  store

#if zstd

Check upgrading to a zstd revlog
--------------------------------

upgrade

  $ hg --config format.revlog-compression=zstd debugupgraderepo --run  --no-backup --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store
     added: revlog-compression-zstd, sparserevlog
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ hg debugformat -v
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zstd   zlib    zlib
  compression-level:  default default default
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlog-compression-zstd
  revlogv1
  sparserevlog
  store

downgrade

  $ hg debugupgraderepo --run --no-backup --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
     removed: revlog-compression-zstd
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ hg debugformat -v
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib
  compression-level:  default default default
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  sparserevlog
  store

upgrade from hgrc

  $ cat >> .hg/hgrc << EOF
  > [format]
  > revlog-compression=zstd
  > EOF
  $ hg debugupgraderepo --run --no-backup --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store
     added: revlog-compression-zstd
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ hg debugformat -v
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zstd   zstd    zlib
  compression-level:  default default default
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlog-compression-zstd
  revlogv1
  sparserevlog
  store

#endif

Check upgrading to a side-data revlog
-------------------------------------

upgrade

  $ hg --config format.exp-use-side-data=yes debugupgraderepo --run  --no-backup --config "extensions.sidedata=$TESTDIR/testlib/ext-sidedata.py" --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, store (no-zstd !)
     preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, revlogv1, sparserevlog, store (zstd !)
     added: exp-sidedata-flag (zstd !)
     added: exp-sidedata-flag, sparserevlog (no-zstd !)
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ hg debugformat -v
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:           yes     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib (no-zstd !)
  compression:        zstd   zstd    zlib (zstd !)
  compression-level:  default default default
  $ cat .hg/requires
  dotencode
  exp-sidedata-flag
  fncache
  generaldelta
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store
  $ hg debugsidedata -c 0
  2 sidedata entries
   entry-0001 size 4
   entry-0002 size 32

downgrade

  $ hg debugupgraderepo --config format.exp-use-side-data=no --run --no-backup --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-zstd !)
     preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, revlogv1, sparserevlog, store (zstd !)
     removed: exp-sidedata-flag
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ hg debugformat -v
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:            no     no      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib (no-zstd !)
  compression:        zstd   zstd    zlib (zstd !)
  compression-level:  default default default
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store
  $ hg debugsidedata -c 0

upgrade from hgrc

  $ cat >> .hg/hgrc << EOF
  > [format]
  > exp-use-side-data=yes
  > EOF
  $ hg debugupgraderepo --run --no-backup --quiet
  upgrade will perform the following actions:
  
  requirements
     preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-zstd !)
     preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, revlogv1, sparserevlog, store (zstd !)
     added: exp-sidedata-flag
  
  processed revlogs:
    - all-filelogs
    - changelog
    - manifest
  
  $ hg debugformat -v
  format-variant     repo config default
  fncache:            yes    yes     yes
  dotencode:          yes    yes     yes
  generaldelta:       yes    yes     yes
  exp-sharesafe:       no     no      no
  sparserevlog:       yes    yes     yes
  sidedata:           yes    yes      no
  persistent-nodemap:  no     no      no
  copies-sdc:          no     no      no
  plain-cl-delta:     yes    yes     yes
  compression:        zlib   zlib    zlib (no-zstd !)
  compression:        zstd   zstd    zlib (zstd !)
  compression-level:  default default default
  $ cat .hg/requires
  dotencode
  exp-sidedata-flag
  fncache
  generaldelta
  revlog-compression-zstd (zstd !)
  revlogv1
  sparserevlog
  store
  $ hg debugsidedata -c 0