compression: introduce a `storage.revlog.zstd.level` configuration This option control the zstd compression level used when compressing revlog chunk. The usage of zstd for revlog compression has not graduated from experimental yet, but we intend to fix that soon. The option name for the compression level is more straight forward to pick, so this changesets comes first. Having a dedicated option for each compression engine is useful because they don't support the same range of values. I ran the same measurement as for the zlib compression level (in the parent changesets). The variation in repository size is stay mostly in the same (small) range. The "read/write" performance see smallish variation, but are overall much better than zlib. Write performance show the same tend of having better write performance for when reaching high-end compression. Again, we don't intend to change the default zstd compression level (currently: 3) in this series. However this is worth investigating in the future. The Performance comparison of zlib vs zstd is quite impressive. The repository size stay in the same range, but the performance are much better in all situations. Comparison summary ================== We are looking at: - performance range for zlib - performance range for zstd - comparison of default zstd (level-3) to default zlib (level 6) - comparison of the slowest zstd time to the fastest zlib time Read performance: ----------------- | zlib | zstd | cmp | f2s mercurial | 0.170159 - 0.189219 | 0.144127 - 0.149624 | 80% | 88% pypy | 2.679217 - 2.768691 | 1.532317 - 1.705044 | 60% | 63% netbeans | 122.477027 - 141.620281 | 72.996346 - 89.731560 | 58% | 73% mozilla | 147.867662 - 170.572118 | 91.700995 - 105.853099 | 56% | 71% Write performance: ------------------ | zlib | zstd | cmp | f2s mercurial | 53.250304 - 56.2936129 | 40.877025 - 45.677286 | 75% | 86% pypy | 460.721984 - 476.589918 | 270.545409 - 301.002219 | 63% | 65% netbeans | 520.560316 - 715.930400 | 370.356311 - 428.329652 | 55% | 82% mozilla | 739.803002 - 987.056093 | 505.152906 - 591.930683 | 57% | 80% Raw data -------- repo alg lvl .hg/store size 00manifest.d read write mercurial zlib 1 49,402,813 5,963,475 0.170159 53.250304 mercurial zlib 6 47,197,397 5,875,730 0.182820 56.264320 mercurial zlib 9 47,121,596 5,849,781 0.189219 56.293612 mercurial zstd 1 49,737,084 5,966,355 0.144127 40.877025 mercurial zstd 3 48,961,867 5,895,208 0.146376 42.268142 mercurial zstd 5 48,200,592 5,938,676 0.149624 43.162875 mercurial zstd 10 47,833,520 5,913,353 0.145185 44.012489 mercurial zstd 15 47,314,604 5,728,679 0.147686 45.677286 mercurial zstd 20 47,330,502 5,830,539 0.145789 45.025407 mercurial zstd 22 47,330,076 5,830,539 0.143996 44.690460 pypy zlib 1 370,830,572 28,462,425 2.679217 460.721984 pypy zlib 6 340,112,317 27,648,747 2.768691 467.537158 pypy zlib 9 338,360,736 27,639,003 2.763495 476.589918 pypy zstd 1 362,377,479 27,916,214 1.532317 270.545409 pypy zstd 3 354,137,693 27,905,988 1.686718 294.951509 pypy zstd 5 342,640,043 27,655,774 1.705044 301.002219 pypy zstd 10 334,224,327 27,164,493 1.567287 285.186239 pypy zstd 15 329,000,363 26,645,965 1.637729 299.561332 pypy zstd 20 324,534,039 26,199,547 1.526813 302.149827 pypy zstd 22 324,530,595 26,198,932 1.525718 307.821218 netbeans zlib 1 1,281,847,810 165,495,457 122.477027 520.560316 netbeans zlib 6 1,205,284,353 159,161,207 139.876147 715.930400 netbeans zlib 9 1,197,135,671 155,034,586 141.620281 678.297064 netbeans zstd 1 1,259,581,737 160,840,613 72.996346 370.356311 netbeans zstd 3 1,232,978,122 157,691,551 81.622317 396.733087 netbeans zstd 5 1,208,034,075 160,246,880 83.080549 364.342626 netbeans zstd 10 1,188,624,176 156,083,417 79.323935 403.594602 netbeans zstd 15 1,176,973,589 153,859,477 89.731560 428.329652 netbeans zstd 20 1,162,958,258 151,147,535 82.842667 392.335349 netbeans zstd 22 1,162,707,029 151,150,220 82.565695 402.840655 mozilla zlib 1 2,775,497,186 298,527,987 147.867662 751.263721 mozilla zlib 6 2,596,856,420 286,597,671 170.572118 987.056093 mozilla zlib 9 2,587,542,494 287,018,264 163.622338 739.803002 mozilla zstd 1 2,723,159,348 286,617,532 91.700995 570.042751 mozilla zstd 3 2,665,055,001 286,152,013 95.240155 561.412805 mozilla zstd 5 2,607,819,817 288,060,030 101.978048 505.152906 mozilla zstd 10 2,558,761,085 283,967,648 104.113481 497.771202 mozilla zstd 15 2,526,216,060 275,581,300 105.853099 591.930683 mozilla zstd 20 2,485,114,806 266,478,859 95.268795 576.515389 mozilla zstd 22 2,484,869,080 266,456,505 94.429282 572.785537

     1

A new repository uses zlib storage, which doesn't need a requirement

     2

     3

  $ hg init default

     4

  $ cd default

     5

  $ cat .hg/requires

     6

  dotencode

     7

  fncache

     8

  generaldelta

     9

  revlogv1

    10

  sparserevlog

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  store

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  testonly-simplestore (reposimplestore !)

    13

    14

  $ touch foo

    15

  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text to trigger compression'

    16

  $ hg debugrevlog -c | grep 0x78

    17

      0x78 (x)  :   1 (100.00%)

    18

      0x78 (x)  : 110 (100.00%)

    19

    20

  $ cd ..

    21

    22

Unknown compression engine to format.compression aborts

    23

    24

  $ hg --config experimental.format.compression=unknown init unknown

    25

  abort: compression engine unknown defined by experimental.format.compression not available

    26

  (run "hg debuginstall" to list available compression engines)

    27

  [255]

    28

    29

A requirement specifying an unknown compression engine results in bail

    30

    31

  $ hg init unknownrequirement

    32

  $ cd unknownrequirement

    33

  $ echo exp-compression-unknown >> .hg/requires

    34

  $ hg log

    35

  abort: repository requires features unknown to this Mercurial: exp-compression-unknown!

    36

  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)

    37

  [255]

    38

    39

  $ cd ..

    40

    41

#if zstd

    42

    43

  $ hg --config experimental.format.compression=zstd init zstd

    44

  $ cd zstd

    45

  $ cat .hg/requires

    46

  dotencode

    47

  exp-compression-zstd

    48

  fncache

    49

  generaldelta

    50

  revlogv1

    51

  sparserevlog

    52

  store

    53

  testonly-simplestore (reposimplestore !)

    54

    55

  $ touch foo

    56

  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text'

    57

    58

  $ hg debugrevlog -c | grep 0x28

    59

      0x28      :  1 (100.00%)

    60

      0x28      : 98 (100.00%)

    61

    62

  $ cd ..

    63

    64

Specifying a new format.compression on an existing repo won't introduce data

    65

with that engine or a requirement

    66

    67

  $ cd default

    68

  $ touch bar

    69

  $ hg --config experimental.format.compression=zstd -q commit -A -m 'add bar with a lot of repeated repeated repeated text'

    70

    71

  $ cat .hg/requires

    72

  dotencode

    73

  fncache

    74

  generaldelta

    75

  revlogv1

    76

  sparserevlog

    77

  store

    78

  testonly-simplestore (reposimplestore !)

    79

    80

  $ hg debugrevlog -c | grep 0x78

    81

      0x78 (x)  :   2 (100.00%)

    82

      0x78 (x)  : 199 (100.00%)

    83

    84

#endif

    85

    86

checking zlib options

    87

=====================

    88

    89

  $ hg init zlib-level-default

    90

  $ hg init zlib-level-1

    91

  $ cat << EOF >> zlib-level-1/.hg/hgrc

    92

  > [storage]

    93

  > revlog.zlib.level=1

    94

  > EOF

    95

  $ hg init zlib-level-9

    96

  $ cat << EOF >> zlib-level-9/.hg/hgrc

    97

  > [storage]

    98

  > revlog.zlib.level=9

    99

  > EOF

   100

   101

   102

  $ commitone() {

   103

  >    repo=$1

   104

  >    cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a

   105

  >    hg -R $repo add $repo/a

   106

  >    hg -R $repo commit -m some-commit

   107

  > }

   108

   109

  $ for repo in zlib-level-default zlib-level-1 zlib-level-9; do

   110

  >     commitone $repo

   111

  > done

   112

   113

  $ $RUNTESTDIR/f -s */.hg/store/data/*

   114

  zlib-level-1/.hg/store/data/a.i: size=4146

   115

  zlib-level-9/.hg/store/data/a.i: size=4138

   116

  zlib-level-default/.hg/store/data/a.i: size=4138

   117

   118

Test error cases

   119

   120

  $ hg init zlib-level-invalid

   121

  $ cat << EOF >> zlib-level-invalid/.hg/hgrc

   122

  > [storage]

   123

  > revlog.zlib.level=foobar

   124

  > EOF

   125

  $ commitone zlib-level-invalid

   126

  abort: storage.revlog.zlib.level is not a valid integer ('foobar')

   127

  abort: storage.revlog.zlib.level is not a valid integer ('foobar')

   128

  [255]

   129

   130

  $ hg init zlib-level-out-of-range

   131

  $ cat << EOF >> zlib-level-out-of-range/.hg/hgrc

   132

  > [storage]

   133

  > revlog.zlib.level=42

   134

  > EOF

   135

   136

  $ commitone zlib-level-out-of-range

   137

  abort: invalid value for `storage.revlog.zlib.level` config: 42

   138

  abort: invalid value for `storage.revlog.zlib.level` config: 42

   139

  [255]

   140

   141

checking zstd options

   142

=====================

   143

   144

  $ hg init zstd-level-default --config experimental.format.compression=zstd

   145

  $ hg init zstd-level-1 --config experimental.format.compression=zstd

   146

  $ cat << EOF >> zstd-level-1/.hg/hgrc

   147

  > [storage]

   148

  > revlog.zstd.level=1

   149

  > EOF

   150

  $ hg init zstd-level-22 --config experimental.format.compression=zstd

   151

  $ cat << EOF >> zstd-level-22/.hg/hgrc

   152

  > [storage]

   153

  > revlog.zstd.level=22

   154

  > EOF

   155

   156

   157

  $ commitone() {

   158

  >    repo=$1

   159

  >    cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a

   160

  >    hg -R $repo add $repo/a

   161

  >    hg -R $repo commit -m some-commit

   162

  > }

   163

   164

  $ for repo in zstd-level-default zstd-level-1 zstd-level-22; do

   165

  >     commitone $repo

   166

  > done

   167

   168

  $ $RUNTESTDIR/f -s zstd-*/.hg/store/data/*

   169

  zstd-level-1/.hg/store/data/a.i: size=4097

   170

  zstd-level-22/.hg/store/data/a.i: size=4091

   171

  zstd-level-default/.hg/store/data/a.i: size=4094

   172

   173

Test error cases

   174

   175

  $ hg init zstd-level-invalid --config experimental.format.compression=zstd

   176

  $ cat << EOF >> zstd-level-invalid/.hg/hgrc

   177

  > [storage]

   178

  > revlog.zstd.level=foobar

   179

  > EOF

   180

  $ commitone zstd-level-invalid

   181

  abort: storage.revlog.zstd.level is not a valid integer ('foobar')

   182

  abort: storage.revlog.zstd.level is not a valid integer ('foobar')

   183

  [255]

   184

   185

  $ hg init zstd-level-out-of-range --config experimental.format.compression=zstd

   186

  $ cat << EOF >> zstd-level-out-of-range/.hg/hgrc

   187

  > [storage]

   188

  > revlog.zstd.level=42

   189

  > EOF

   190

   191

  $ commitone zstd-level-out-of-range

   192

  abort: invalid value for `storage.revlog.zstd.level` config: 42

   193

  abort: invalid value for `storage.revlog.zstd.level` config: 42

   194

  [255]

   195