diff tests/test-rebase-conflicts.t @ 36965:b89a7ef29013

bundle: include advisory rev branch cache part in bundle2 bundle

`hg bundle` command producing bundle2 will now include an optional part
containing the revision-branch cache data.

The data sent are mostly nodes so it is quite compact.  The goal of the
rev-branch-cache is to speed up branch map computation, especially when the
branchmap gets invalidated so we send data for all exchanged changesets. In
addition, computing the relevant heads to send in case of partial pulling would
be challenging.

As a reminder, the rev branch cache data significantly speed up branch
computation. Having it around provides a small speedup to pull/clone and much
higher tolerance to branch map cache invalidation that might happens from later
commands.

On the Mercurial repository, computing the visible branchmap from scratch move
from 2.00 seconds to 0.34s (a -83% speedup).

Using this new part, Unbundling the full Mercurial repository moves from 25.736
seconds to 24.030 seconds (around -7% speedup). The bundle size increase is
around 3% (from 22.43 MB to 23.13MB)


On an half a million revision repository with twenty thousand
branches, computing the branchmap moves from 75 seconds to 45 second (-40%) if
the caches is used.

A bundle containing 50 000 changesets in such repository get a 0.5% size
increase from such part for a -3% unbundling time speedup.

--- a/tests/test-rebase-conflicts.t	Wed Feb 21 17:26:22 2018 +0100
+++ b/tests/test-rebase-conflicts.t	Wed Feb 21 17:33:00 2018 +0100
@@ -297,8 +297,9 @@
   list of changesets:
   e31216eec445e44352c5f01588856059466a24c9
   2f2496ddf49d69b5ef23ad8cf9fb2e0e4faf0ac2
-  bundle2-output-bundle: "HG20", (1 params) 2 parts total
+  bundle2-output-bundle: "HG20", (1 params) 3 parts total
   bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
+  bundle2-output-part: "cache:rev-branch-cache" streamed payload
   bundle2-output-part: "phase-heads" 24 bytes payload
   saved backup bundle to $TESTTMP/issue4041/.hg/strip-backup/e31216eec445-15f7a814-rebase.hg
   3 changesets found
@@ -306,8 +307,9 @@
   4c9fbe56a16f30c0d5dcc40ec1a97bbe3325209c
   19c888675e133ab5dff84516926a65672eaf04d9
   2a7f09cac94c7f4b73ebd5cd1a62d3b2e8e336bf
-  bundle2-output-bundle: "HG20", 2 parts total
+  bundle2-output-bundle: "HG20", 3 parts total
   bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
+  bundle2-output-part: "cache:rev-branch-cache" streamed payload
   bundle2-output-part: "phase-heads" 24 bytes payload
   adding branch
   bundle2-input-bundle: with-transaction
@@ -321,12 +323,15 @@
   adding f1.txt revisions
   added 2 changesets with 2 changes to 1 files
   bundle2-input-part: total payload size 1686
+  bundle2-input-part: "cache:rev-branch-cache" supported
+  bundle2-input-part: total payload size 74
   bundle2-input-part: "phase-heads" supported
   bundle2-input-part: total payload size 24
-  bundle2-input-bundle: 1 parts total
+  bundle2-input-bundle: 2 parts total
   updating the branch cache
   invalid branchheads cache (served): tip differs
   rebase completed
+  truncating cache/rbc-revs-v1 to 0
 
 Test minimization of merge conflicts
   $ hg up -q null