view tests/test-convert-splicemap.t @ 49777:e1953a34c110

bundle: emit full snapshot as is, without doing a redelta

With the new `forced` delta-reused policy, it become important to be able to
send full snapshot where full snapshot are needed. Otherwise, the fallback delta
will simply be used on the client side… creating monstrous delta chain, since
revision that are meant as a reset of delta-chain chain becoming too complex are
simply adding a new full delta-tree on the leaf of another one.

In the `non-forced` cases, client process full snapshot from the bundle
differently from deltas, so client will still try to convert the full snapshot
into a delta if possible. So this will no lead to pathological storage
explosion.

I have considered making this configurable, but the impact seems limited enough
that it does not seems to be worth it. Especially with the current
sparse-revlog format that use "delta-tree" with multiple level snapshots, full
snapshot are much less frequent and not that different from other intermediate
snapshot that we are already sending over the wire anyway.

CPU wise, this will help the bundling side a little as it will not need to
reconstruct revisions and compute deltas. The unbundling side might save a tiny
amount of CPU as it won't need to reconstruct the delta-base to reconstruct the
revision full text. This only slightly visible in some of the benchmarks. And
have no real impact on most of them.

### data-env-vars.name      = pypy-2018-08-01-zstd-sparse-revlog
  # benchmark.name          = perf-bundle
  # benchmark.variants.revs = last-40000
before:          11.467186 seconds
just-emit-full:  11.190576 seconds   (-2.41%)
with-pull-force: 11.041091 seconds   (-3.72%)
  # benchmark.name          = perf-unbundle
  # benchmark.variants.revs = last-40000
before:     16.744862
just-emit-full:: 16.561036 seconds   (-1.10%)
with-pull-force: 16.389344 seconds   (-2.12%)
  # benchmark.name          = pull
  # benchmark.variants.revs = last-40000
before:     26.870569
just-emit-full:  26.391188 seconds   (-1.78%)
with-pull-force: 25.633184 seconds   (-4.60%)


Space wise (so network-wise) the impact is fairly small. When taking compression into
account.

Below are tests the size of `hg bundle --all` for a handful of benchmark repositories
(with bzip, zstd compression and without it)

This show a small increase in the bundle size, but nothing really significant
except maybe for mozilla-try (+12%) that nobody really pulls large chunk of anyway.
Mozilla-try is also the repository that benefit the most for not having to
recompute deltas client size.

### mercurial:
bzip-before:     26 406 342 bytes
bzip-after:      26 691 543 bytes  +1.08%

zstd-before:     27 918 645 bytes
zstd-after:      28 075 896 bytes  +0.56%

none-before:     98 675 601 bytes
none-after:     100 411 237 bytes  +1.76%


### pypy
bzip-before:    201 295 752 bytes
bzip-after:     209 780 282 bytes  +4.21%

zstd-before:    202 974 795 bytes
zstd-after:     205 165 780 bytes  +1.08%

none-before:    871 070 261 bytes
none-after:     993 595 057 bytes +14.07%


### netbeans
bzip-before:    601 314 330 bytes
bzip-after:     614 246 241 bytes  +2.15%

zstd-before:    604 745 136 bytes
zstd-after:     615 497 705 bytes  +1.78%

none-before:  3 338 238 571 bytes
none-after:   3 439 422 535 bytes  +3.03%


### mozilla-central
bzip-before:  1 493 006 921 bytes
bzip-after:   1 549 650 570 bytes  +3.79%

zstd-before:  1 481 910 102 bytes
zstd-after:   1 513 052 415 bytes  +2.10%

none-before:  6 535 929 910 bytes
none-after:   7 010 191 342 bytes  +7.26%


### mozilla-try
bzip-before:  6 583 425 999 bytes
bzip-after:   7 423 536 928 bytes +12.76%

zstd-before:  6 021 009 212 bytes
zstd-after:   6 674 922 420 bytes +10.86%

none-before: 22 954 739 558 bytes
none-after:  26 013 854 771 bytes +13.32%

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert=" >> $HGRCPATH
  $ glog()
  > {
  >     hg log -G --template '{rev}:{node|short} "{desc|firstline}"\
  >  files: {files}\n' "$@"
  > }
  $ hg init repo1
  $ cd repo1
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ echo b > b
  $ echo a >> a
  $ hg ci -Am addb
  adding b
  $ PARENTID1=`hg id --debug -i`
  $ echo c > c
  $ hg ci -Am addc
  adding c
  $ PARENTID2=`hg id --debug -i`
  $ cd ..
  $ glog -R repo1
  @  2:e55c719b85b6 "addc" files: c
  |
  o  1:6d4c2037ddc2 "addb" files: a b
  |
  o  0:07f494440405 "adda" files: a
  

  $ hg init repo2
  $ cd repo2
  $ echo b > a
  $ echo d > d
  $ hg ci -Am addaandd
  adding a
  adding d
  $ INVALIDID1=afd12345af
  $ INVALIDID2=28173x36ddd1e67bf7098d541130558ef5534a86
  $ CHILDID1=`hg id --debug -i`
  $ echo d >> d
  $ hg ci -Am changed
  $ CHILDID2=`hg id --debug -i`
  $ echo e > e
  $ hg ci -Am adde
  adding e
  $ cd ..
  $ glog -R repo2
  @  2:a39b65753b0a "adde" files: e
  |
  o  1:e4ea00df9189 "changed" files: d
  |
  o  0:527cdedf31fb "addaandd" files: a d
  

test invalid splicemap1

  $ cat > splicemap <<EOF
  > $CHILDID2
  > EOF
  $ hg convert --splicemap splicemap repo2 repo1
  abort: syntax error in splicemap(1): child parent1[,parent2] expected
  [255]

test invalid splicemap2

  $ cat > splicemap <<EOF
  > $CHILDID2 $PARENTID1, $PARENTID2, $PARENTID2
  > EOF
  $ hg convert --splicemap splicemap repo2 repo1
  abort: syntax error in splicemap(1): child parent1[,parent2] expected
  [255]

test invalid splicemap3

  $ cat > splicemap <<EOF
  > $INVALIDID1 $INVALIDID2
  > EOF
  $ hg convert --splicemap splicemap repo2 repo1
  abort: splicemap entry afd12345af is not a valid revision identifier
  [255]

splice repo2 on repo1

  $ cat > splicemap <<EOF
  > $CHILDID1 $PARENTID1
  > $CHILDID2 $PARENTID2,$CHILDID1
  > 
  > EOF
  $ cat splicemap
  527cdedf31fbd5ea708aa14eeecf53d4676f38db 6d4c2037ddc2cb2627ac3a244ecce35283268f8e
  e4ea00df91897da3079a10fab658c1eddba6617b e55c719b85b60e5102fac26110ba626e7cb6b7dc,527cdedf31fbd5ea708aa14eeecf53d4676f38db
  
  $ hg clone repo1 target1
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg convert --splicemap splicemap repo2 target1
  scanning source...
  sorting...
  converting...
  2 addaandd
  spliced in 6d4c2037ddc2cb2627ac3a244ecce35283268f8e as parents of 527cdedf31fbd5ea708aa14eeecf53d4676f38db
  1 changed
  spliced in e55c719b85b60e5102fac26110ba626e7cb6b7dc and 527cdedf31fbd5ea708aa14eeecf53d4676f38db as parents of e4ea00df91897da3079a10fab658c1eddba6617b
  0 adde
  $ glog -R target1
  o  5:16bc847b02aa "adde" files: e
  |
  o    4:e30e4fee3418 "changed" files: d
  |\
  | o  3:e673348c3a3c "addaandd" files: a d
  | |
  @ |  2:e55c719b85b6 "addc" files: c
  |/
  o  1:6d4c2037ddc2 "addb" files: a b
  |
  o  0:07f494440405 "adda" files: a
  



Test splicemap and conversion order

  $ hg init ordered
  $ cd ordered
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ hg branch branch
  marked working directory as branch branch
  (branches are permanent and global, did you want a bookmark?)
  $ echo a >> a
  $ hg ci -Am changea
  $ echo a >> a
  $ hg ci -Am changeaagain
  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b > b
  $ hg ci -Am addb
  adding b

We want 2 to depend on 1 and 3. Since 3 is always converted after 2,
the bug should be exhibited with all conversion orders.

  $ cat > ../splicemap <<EOF
  > `(hg id -r 2 -i --debug)` `(hg id -r 1 -i --debug)`, `(hg id -r 3 -i --debug)`
  > EOF
  $ cd ..
  $ cat splicemap
  7c364e7fa7d70ae525610c016317ed717b519d97 717d54d67e6c31fd75ffef2ff3042bdd98418437, 102a90ea7b4a3361e4082ed620918c261189a36a

Test regular conversion

  $ hg convert --splicemap splicemap ordered ordered-hg1
  initializing destination ordered-hg1 repository
  scanning source...
  sorting...
  converting...
  3 adda
  2 changea
  1 addb
  0 changeaagain
  spliced in 717d54d67e6c31fd75ffef2ff3042bdd98418437 and 102a90ea7b4a3361e4082ed620918c261189a36a as parents of 7c364e7fa7d70ae525610c016317ed717b519d97
  $ glog -R ordered-hg1
  o    3:4cb04b9afbf2 "changeaagain" files: a
  |\
  | o  2:102a90ea7b4a "addb" files: b
  | |
  o |  1:717d54d67e6c "changea" files: a
  |/
  o  0:07f494440405 "adda" files: a
  

Test conversion with parent revisions already in dest, using source
and destination identifiers. Test unknown splicemap target.

  $ hg convert -r1 ordered ordered-hg2
  initializing destination ordered-hg2 repository
  scanning source...
  sorting...
  converting...
  1 adda
  0 changea
  $ hg convert -r3 ordered ordered-hg2
  scanning source...
  sorting...
  converting...
  0 addb
  $ cat > splicemap <<EOF
  > `(hg -R ordered id -r 2 -i --debug)` \
  > `(hg -R ordered-hg2 id -r 1 -i --debug)`,\
  > `(hg -R ordered-hg2 id -r 2 -i --debug)`
  > deadbeef102a90ea7b4a3361e4082ed620918c26 deadbeef102a90ea7b4a3361e4082ed620918c27
  > EOF
  $ hg convert --splicemap splicemap ordered ordered-hg2
  scanning source...
  splice map revision deadbeef102a90ea7b4a3361e4082ed620918c26 is not being converted, ignoring
  sorting...
  converting...
  0 changeaagain
  spliced in 717d54d67e6c31fd75ffef2ff3042bdd98418437 and 102a90ea7b4a3361e4082ed620918c261189a36a as parents of 7c364e7fa7d70ae525610c016317ed717b519d97
  $ glog -R ordered-hg2
  o    3:4cb04b9afbf2 "changeaagain" files: a
  |\
  | o  2:102a90ea7b4a "addb" files: b
  | |
  o |  1:717d54d67e6c "changea" files: a
  |/
  o  0:07f494440405 "adda" files: a
  

Test empty conversion

  $ hg convert --splicemap splicemap ordered ordered-hg2
  scanning source...
  splice map revision deadbeef102a90ea7b4a3361e4082ed620918c26 is not being converted, ignoring
  sorting...
  converting...

Test clonebranches

  $ hg --config convert.hg.clonebranches=true convert \
  >   --splicemap splicemap ordered ordered-hg3
  initializing destination ordered-hg3 repository
  scanning source...
  abort: revision 717d54d67e6c31fd75ffef2ff3042bdd98418437 not found in destination repository (lookups with clonebranches=true are not implemented)
  [255]

Test invalid dependency

  $ cat > splicemap <<EOF
  > `(hg -R ordered id -r 2 -i --debug)` \
  > deadbeef102a90ea7b4a3361e4082ed620918c26,\
  > `(hg -R ordered-hg2 id -r 2 -i --debug)`
  > EOF
  $ hg convert --splicemap splicemap ordered ordered-hg4
  initializing destination ordered-hg4 repository
  scanning source...
  abort: unknown splice map parent: deadbeef102a90ea7b4a3361e4082ed620918c26
  [255]