##// END OF EJS Templates
snapshot: consider all snapshots in the parents' chains...
snapshot: consider all snapshots in the parents' chains There are no reasons to only consider full snapshot as a possible base for an intermediate snapshot. Now that the basic principles have been set, we can start adding more levels of snapshots. We now consider all snapshots in the parent's chains (full or intermediate). This creates a chain of intermediate snapshots, each smaller than the previous one. # Effect On The Test Repository In the test repository, we can see a decrease in the revlog size and slightly shorter delta chain. However, that approach creates snapshots more frequently, increasing the risk of ending into problematic cases in very branchy repositories (not triggered by the test repository). The next changesets will remove that risk by adding logic that increases deltas reuse.

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test-sparse-revlog.t
133 lines | 4.7 KiB | text/troff | Tads3Lexer
/ tests / test-sparse-revlog.t
====================================
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 [ ! -f "$bundlepath" ]; then
> echo 'skipped: missing artifact, run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'
> exit 80
> fi
$ 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 echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'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
> [storage]
> revlog.optimize-delta-parent-choice = yes
> 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=63812493
$ 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 : 179 ( 3.58%)
lvl-0 : 4 ( 0.08%)
lvl-1 : 49 ( 0.98%)
lvl-2 : 56 ( 1.12%)
lvl-3 : 63 ( 1.26%)
lvl-4 : 7 ( 0.14%)
deltas : 4822 (96.42%)
revision size : 63812493
snapshot : 10745878 (16.84%)
lvl-0 : 804204 ( 1.26%)
lvl-1 : 4986508 ( 7.81%)
lvl-2 : 2858810 ( 4.48%)
lvl-3 : 1958906 ( 3.07%)
lvl-4 : 137450 ( 0.22%)
deltas : 53066615 (83.16%)
chunks : 5001
0x78 (x) : 5001 (100.00%)
chunks size : 63812493
0x78 (x) : 63812493 (100.00%)
avg chain length : 17
max chain length : 45
max chain reach : 27506743
compression ratio : 27
uncompressed data size (min/max/avg) : 346468 / 346472 / 346471
full revision size (min/max/avg) : 201007 / 201077 / 201051
inter-snapshot size (min/max/avg) : 13223 / 172097 / 56809
level-1 (min/max/avg) : 13223 / 172097 / 101765
level-2 (min/max/avg) : 28558 / 85237 / 51050
level-3 (min/max/avg) : 14647 / 41752 / 31093
level-4 (min/max/avg) : 18596 / 20760 / 19635
delta size (min/max/avg) : 10649 / 104791 / 11005
deltas against prev : 4171 (86.50%)
where prev = p1 : 4127 (98.95%)
where prev = p2 : 0 ( 0.00%)
other : 44 ( 1.05%)
deltas against p1 : 633 (13.13%)
deltas against p2 : 18 ( 0.37%)
deltas against other : 0 ( 0.00%)