bundle2: make server.bundle2.stream default to True
Support for bundle2 streaming clones has been shipped in Mercurial 4.5
(7eedbd5d4880), but was never activated by default. It's time to have more
people use it. The new format allows streaming clones to transport cache
(hooray for speed) and phaseroots (fixes phase-related issues).
Changes in tests:
bundle2 capabilities now have "stream=v2" (plus a '\n' as a separator) and
therefore take 14 bytes more: "%0Astream%3Dv2". Tip for tests that have data
encoded with CBOR: 0xd3 - 0xc5 = 14.
$USUAL_BUNDLE2_CAPS$ replaces $USUAL_BUNDLE2_CAPS_SERVER$, which is the same
thing, but without "stream=v2".
Since streaming clones now also transfer caches, the reported byte and file
counts are higher (e.g. 816 bytes in 9 files instead of 613 bytes in 4 files,
a bit of --debug and manual math confirms that the caches take these extra 203
bytes in 5 files).
Differential Revision: https://phab.mercurial-scm.org/D4680
====================================
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 echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"'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
> maxchainlen = 15
> [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=63002924
$ 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 : 374 ( 7.48%)
lvl-0 : 4 ( 0.08%)
lvl-1 : 23 ( 0.46%)
lvl-2 : 63 ( 1.26%)
lvl-3 : 118 ( 2.36%)
lvl-4 : 166 ( 3.32%)
deltas : 4627 (92.52%)
revision size : 63002924
snapshot : 9888099 (15.69%)
lvl-0 : 804262 ( 1.28%)
lvl-1 : 1561380 ( 2.48%)
lvl-2 : 2096696 ( 3.33%)
lvl-3 : 2749539 ( 4.36%)
lvl-4 : 2676222 ( 4.25%)
deltas : 53114825 (84.31%)
chunks : 5001
0x78 (x) : 5001 (100.00%)
chunks size : 63002924
0x78 (x) : 63002924 (100.00%)
avg chain length : 9
max chain length : 15
max chain reach : 28907121
compression ratio : 27
uncompressed data size (min/max/avg) : 346468 / 346472 / 346471
full revision size (min/max/avg) : 201008 / 201141 / 201065
inter-snapshot size (min/max/avg) : 11601 / 157413 / 24550
level-1 (min/max/avg) : 13061 / 157413 / 67886
level-2 (min/max/avg) : 11674 / 85631 / 33280
level-3 (min/max/avg) : 11602 / 42957 / 23301
level-4 (min/max/avg) : 11601 / 21475 / 16121
delta size (min/max/avg) : 10649 / 105465 / 11479
deltas against prev : 3966 (85.71%)
where prev = p1 : 3922 (98.89%)
where prev = p2 : 0 ( 0.00%)
other : 44 ( 1.11%)
deltas against p1 : 611 (13.21%)
deltas against p2 : 50 ( 1.08%)
deltas against other : 0 ( 0.00%)