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

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     echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'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=58616973

  $ 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   :             18 ( 0.36%)

        lvl-2   :             62 ( 1.24%)

        lvl-3   :            108 ( 2.16%)

        lvl-4   :            191 ( 3.82%)

        lvl-5   :              1 ( 0.02%)

      deltas    :     4618 (92.34%)

  revision size : 58616973

      snapshot  :  9247844 (15.78%)

        lvl-0   :         539532 ( 0.92%)

        lvl-1   :        1467743 ( 2.50%)

        lvl-2   :        1873820 ( 3.20%)

        lvl-3   :        2326874 ( 3.97%)

        lvl-4   :        3029118 ( 5.17%)

        lvl-5   :          10757 ( 0.02%)

      deltas    : 49369129 (84.22%)

  chunks        :     5001

      0x28      :     5001 (100.00%)

  chunks size   : 58616973

      0x28      : 58616973 (100.00%)

  avg chain length  :        9

  max chain length  :       15

  max chain reach   : 27366701

  compression ratio :       29

  uncompressed data size (min/max/avg) : 346468 / 346472 / 346471

  full revision size (min/max/avg)     : 179288 / 180786 / 179844

  inter-snapshot size (min/max/avg)    : 10757 / 169507 / 22916

      level-1   (min/max/avg)          : 13905 / 169507 / 81541

      level-2   (min/max/avg)          : 10887 / 83873 / 30222

      level-3   (min/max/avg)          : 10911 / 43047 / 21545

      level-4   (min/max/avg)          : 10838 / 21390 / 15859

      level-5   (min/max/avg)          : 10757 / 10757 / 10757

  delta size (min/max/avg)             : 9672 / 108072 / 10690

  deltas against prev  : 3906 (84.58%)

      where prev = p1  : 3906     (100.00%)

      where prev = p2  :    0     ( 0.00%)

      other            :    0     ( 0.00%)

  deltas against p1    :  649 (14.05%)

  deltas against p2    :   63 ( 1.36%)

  deltas against other :    0 ( 0.00%)

Test `debug-delta-find`

-----------------------

  $ ls -1

  SPARSE-REVLOG-TEST-FILE

  $ hg debugdeltachain SPARSE-REVLOG-TEST-FILE | grep snap | tail -1

     4971    4970      -1       3        5     4930    snap      19179     346472     427596   1.23414  15994877  15567281   36.40652     427596     179288   1.00000        5

  $ hg debug-delta-find SPARSE-REVLOG-TEST-FILE 4971

  DBG-DELTAS-SEARCH: SEARCH rev=4971

  DBG-DELTAS-SEARCH: ROUND #1 - 2 candidates - search-down

  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4962

  DBG-DELTAS-SEARCH:     type=snapshot-4

  DBG-DELTAS-SEARCH:     size=18296

  DBG-DELTAS-SEARCH:     base=4930

  DBG-DELTAS-SEARCH:     uncompressed-delta-size=30377

  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)

  DBG-DELTAS-SEARCH:     DELTA: length=16872 (BAD)

  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4971

  DBG-DELTAS-SEARCH:     type=snapshot-4

  DBG-DELTAS-SEARCH:     size=19179

  DBG-DELTAS-SEARCH:     base=4930

  DBG-DELTAS-SEARCH:     TOO-HIGH

  DBG-DELTAS-SEARCH: ROUND #2 - 1 candidates - search-down

  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4930

  DBG-DELTAS-SEARCH:     type=snapshot-3

  DBG-DELTAS-SEARCH:     size=39228

  DBG-DELTAS-SEARCH:     base=4799

  DBG-DELTAS-SEARCH:     uncompressed-delta-size=33050

  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)

  DBG-DELTAS-SEARCH:     DELTA: length=19179 (GOOD)

  DBG-DELTAS-SEARCH: ROUND #3 - 1 candidates - refine-down

  DBG-DELTAS-SEARCH:   CONTENDER: rev=4930 - length=19179

  DBG-DELTAS-SEARCH:   CANDIDATE: rev=4799

  DBG-DELTAS-SEARCH:     type=snapshot-2

  DBG-DELTAS-SEARCH:     size=50213

  DBG-DELTAS-SEARCH:     base=4623

  DBG-DELTAS-SEARCH:     uncompressed-delta-size=82661

  DBG-DELTAS-SEARCH:     delta-search-time=* (glob)

  DBG-DELTAS-SEARCH:     DELTA: length=49132 (BAD)

  DBG-DELTAS: FILELOG:SPARSE-REVLOG-TEST-FILE: rev=4971: search-rounds=3 try-count=3 - delta-type=snapshot snap-depth=4 - p1-chain-length=15 p2-chain-length=-1 - duration=* (glob)

  $ cd ..