view tests/test-convert-bzr-merges.t @ 23810:b681d3a2bf04

setdiscovery: randomly pick between heads and sample when taking full sample

Before this changeset, the discovery protocol was too heads-centric. Heads of the
undiscovered set were always sent for discovery and any room remaining in the
sample were filled with exponential samples (and random ones if any room
remained).

This behaved extremely poorly when the number of heads exceeded the sample size,
because we keep just asking about the existence of heads, then their direct parent
and so on. As a result, the 'O(log(len(repo)))' discovery turns into a
'O(len(repo))' one. As a solution we take a random sample of the heads plus
exponential samples. This way we ensure some exponential sampling is achieved,
bringing back some logarithmic convergence of the discovery again.

This patch only applies this principle in one place. More places will be updated
in future patches.

One test is impacted because the random sample happen to be different. By
chance, it helps a bit in this case.

N.B. bzr 1.13 has a bug that breaks this test.  If you see this
test fail, check your bzr version.  Upgrading to bzr 1.13.1
should fix it.

  $ . "$TESTDIR/bzr-definitions"

test multiple merges at once

  $ mkdir test-multimerge
  $ cd test-multimerge
  $ bzr init -q source
  $ cd source
  $ echo content > file
  $ bzr add -q file
  $ bzr commit -q -m 'Initial add'
  $ cd ..
  $ bzr branch -q source source-branch1
  $ cd source-branch1
  $ echo morecontent >> file
  $ echo evenmorecontent > file-branch1
  $ bzr add -q file-branch1
  $ bzr commit -q -m 'Added branch1 file'
  $ cd ../source
  $ sleep 1
  $ echo content > file-parent
  $ bzr add -q file-parent
  $ bzr commit -q -m 'Added parent file'
  $ cd ..
  $ bzr branch -q source source-branch2
  $ cd source-branch2
  $ echo somecontent > file-branch2
  $ bzr add -q file-branch2
  $ bzr commit -q -m 'Added brach2 file'
  $ sleep 1
  $ cd ../source
  $ bzr merge -q ../source-branch1
  $ bzr merge -q --force ../source-branch2
  $ bzr commit -q -m 'Merged branches'
  $ cd ..
  $ hg convert --datesort source source-hg
  initializing destination source-hg repository
  scanning source...
  sorting...
  converting...
  4 Initial add
  3 Added branch1 file
  2 Added parent file
  1 Added brach2 file
  0 Merged branches
  $ glog -R source-hg
  o    5@source "(octopus merge fixup)" files:
  |\
  | o    4@source "Merged branches" files: file-branch2
  | |\
  o---+  3@source-branch2 "Added brach2 file" files: file-branch2
   / /
  | o  2@source "Added parent file" files: file-parent
  | |
  o |  1@source-branch1 "Added branch1 file" files: file file-branch1
  |/
  o  0@source "Initial add" files: file
  
  $ manifest source-hg tip
  % manifest of tip
  644   file
  644   file-branch1
  644   file-branch2
  644   file-parent

  $ cd ..