view tests/test-sparse-revlog.t @ 49788:31b4675ca998 stable

emitrevision: if we need to compute a delta on the fly, try p1 or p2 first Falling back to `prev` does not yield any real value on modern storage and result in pathological changes to be created on the other side. Doing a delta against a parent will likely be smaller (helping the network) and will be safer to apply on the client (helping future pulls by Triggering intermediate snapshop where they will be needed by later deltas).
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Thu, 24 Nov 2022 04:04:19 +0100
parents fa8d974284f8
children 266bb5c86f4b
line wrap: on
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====================================
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     echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'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 ..