view tests/test-sparse-revlog.t @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

====================================
Test delta choice with sparse revlog
====================================

Sparse-revlog usually shows the most gain on Manifest. However, it is simpler
to general an appropriate file, so we test with a single file instead. The
goal is to observe intermediate snapshot being created.

We need a large enough file. Part of the content needs to be replaced
repeatedly while some of it changes rarely.

  $ bundlepath="$TESTDIR/artifacts/cache/big-file-churn.hg"

  $ expectedhash=`cat "$bundlepath".md5`

#if slow

  $ if [ ! -f "$bundlepath" ]; then
  >     "$TESTDIR"/artifacts/scripts/generate-churning-bundle.py > /dev/null
  > fi

#else

  $ if [ ! -f "$bundlepath" ]; then
  >     echo 'skipped: missing artifact, run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'
  >     exit 80
  > fi

#endif

  $ currenthash=`f -M "$bundlepath" | cut -d = -f 2`
  $ if [ "$currenthash" != "$expectedhash" ]; then
  >     echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'
  >     exit 80
  > fi

  $ cat >> $HGRCPATH << EOF
  > [format]
  > sparse-revlog = yes
  > maxchainlen = 15
  > [storage]
  > revlog.optimize-delta-parent-choice = yes
  > revlog.reuse-external-delta = no
  > EOF
  $ hg init sparse-repo
  $ cd sparse-repo
  $ hg unbundle $bundlepath
  adding changesets
  adding manifests
  adding file changes
  added 5001 changesets with 5001 changes to 1 files (+89 heads)
  new changesets 9706f5af64f4:d9032adc8114 (5001 drafts)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  updated to "d9032adc8114: commit #5000"
  89 other heads for branch "default"

  $ hg log --stat -r 0:3
  changeset:   0:9706f5af64f4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     initial commit
  
   SPARSE-REVLOG-TEST-FILE |  10500 ++++++++++++++++++++++++++++++++++++++++++++++
   1 files changed, 10500 insertions(+), 0 deletions(-)
  
  changeset:   1:724907deaa5e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit #1
  
   SPARSE-REVLOG-TEST-FILE |  1068 +++++++++++++++++++++++-----------------------
   1 files changed, 534 insertions(+), 534 deletions(-)
  
  changeset:   2:62c41bce3e5d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit #2
  
   SPARSE-REVLOG-TEST-FILE |  1068 +++++++++++++++++++++++-----------------------
   1 files changed, 534 insertions(+), 534 deletions(-)
  
  changeset:   3:348a9cbd6959
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit #3
  
   SPARSE-REVLOG-TEST-FILE |  1068 +++++++++++++++++++++++-----------------------
   1 files changed, 534 insertions(+), 534 deletions(-)
  

  $ f -s .hg/store/data/*.d
  .hg/store/data/_s_p_a_r_s_e-_r_e_v_l_o_g-_t_e_s_t-_f_i_l_e.d: size=63327412
  $ hg debugrevlog *
  format : 1
  flags  : generaldelta
  
  revisions     :     5001
      merges    :      625 (12.50%)
      normal    :     4376 (87.50%)
  revisions     :     5001
      empty     :        0 ( 0.00%)
                     text  :        0 (100.00%)
                     delta :        0 (100.00%)
      snapshot  :      383 ( 7.66%)
        lvl-0   :              3 ( 0.06%)
        lvl-1   :             20 ( 0.40%)
        lvl-2   :             68 ( 1.36%)
        lvl-3   :            112 ( 2.24%)
        lvl-4   :            180 ( 3.60%)
      deltas    :     4618 (92.34%)
  revision size : 63327412
      snapshot  :  9886710 (15.61%)
        lvl-0   :         603104 ( 0.95%)
        lvl-1   :        1559991 ( 2.46%)
        lvl-2   :        2295592 ( 3.62%)
        lvl-3   :        2531199 ( 4.00%)
        lvl-4   :        2896824 ( 4.57%)
      deltas    : 53440702 (84.39%)
  
  chunks        :     5001
      0x78 (x)  :     5001 (100.00%)
  chunks size   : 63327412
      0x78 (x)  : 63327412 (100.00%)
  
  avg chain length  :        9
  max chain length  :       15
  max chain reach   : 28248745
  compression ratio :       27
  
  uncompressed data size (min/max/avg) : 346468 / 346472 / 346471
  full revision size (min/max/avg)     : 201008 / 201050 / 201034
  inter-snapshot size (min/max/avg)    : 11596 / 168150 / 24430
      level-1   (min/max/avg)          : 16653 / 168150 / 77999
      level-2   (min/max/avg)          : 12951 / 85595 / 33758
      level-3   (min/max/avg)          : 11608 / 43029 / 22599
      level-4   (min/max/avg)          : 11596 / 21632 / 16093
  delta size (min/max/avg)             : 10649 / 107163 / 11572
  
  deltas against prev  : 3910 (84.67%)
      where prev = p1  : 3910     (100.00%)
      where prev = p2  :    0     ( 0.00%)
      other            :    0     ( 0.00%)
  deltas against p1    :  648 (14.03%)
  deltas against p2    :   60 ( 1.30%)
  deltas against other :    0 ( 0.00%)