--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-sparse-revlog.t Mon Sep 10 09:08:24 2018 -0700
@@ -0,0 +1,121 @@
+====================================
+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 echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'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=74365490
+ $ 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 : 101 ( 2.02%)
+ lvl-0 : 101 ( 2.02%)
+ deltas : 4900 (97.98%)
+ revision size : 74365490
+ snapshot : 20307865 (27.31%)
+ lvl-0 : 20307865 (27.31%)
+ deltas : 54057625 (72.69%)
+
+ chunks : 5001
+ 0x78 (x) : 5001 (100.00%)
+ chunks size : 74365490
+ 0x78 (x) : 74365490 (100.00%)
+
+ avg chain length : 23
+ max chain length : 45
+ max chain reach : 11039464
+ compression ratio : 23
+
+ uncompressed data size (min/max/avg) : 346468 / 346472 / 346471
+ full revision size (min/max/avg) : 200927 / 201202 / 201067
+ inter-snapshot size (min/max/avg) : 0 / 0 / 0
+ delta size (min/max/avg) : 10649 / 103898 / 11032
+
+ deltas against prev : 4231 (86.35%)
+ where prev = p1 : 4172 (98.61%)
+ where prev = p2 : 0 ( 0.00%)
+ other : 59 ( 1.39%)
+ deltas against p1 : 651 (13.29%)
+ deltas against p2 : 18 ( 0.37%)
+ deltas against other : 0 ( 0.00%)