view tests/test-merge6.t @ 33269:ead6749354e1

phabricator: try to fetch differential revisions in batch

Previously, we read Differential Revisions one by one by calling
`differential.query`.

Fetching them one by one is suboptimal. Unfortunately, there is no Conduit
API that allows us to get a stack of diffids using a single API call.

This patch tries to be smarter using a simple heuristic: when fetching D59
as a stack, previous IDs like D51, D52, D53, ..., D58 are likely belonging
to a same stack so just fetch them as well. Since `differential.query` only
returns cheap metadata without expensive diff content, it shouldn't be a big
problem for the server.

Using a test Phabricator instance, this patch reduces `phabread` reading a
10 patch stack from about 13 to 30 seconds to 8 seconds.

  $ cat <<EOF > merge
  > import sys, os
  > print "merging for", os.path.basename(sys.argv[1])
  > EOF
  $ HGMERGE="python ../merge"; export HGMERGE

  $ hg init A1
  $ cd A1
  $ echo This is file foo1 > foo
  $ echo This is file bar1 > bar
  $ hg add foo bar
  $ hg commit -m "commit text"

  $ cd ..
  $ hg clone A1 B1
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd A1
  $ rm bar
  $ hg remove bar
  $ hg commit -m "commit test"

  $ cd ../B1
  $ echo This is file foo22 > foo
  $ hg commit -m "commit test"

  $ cd ..
  $ hg clone A1 A2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone B1 B2
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd A1
  $ hg pull ../B1
  pulling from ../B1
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg commit -m "commit test"
bar should remain deleted.
  $ hg manifest --debug
  f9b0e817f6a48de3564c6b2957687c5e7297c5a0 644   foo

  $ cd ../B2
  $ hg pull ../A2
  pulling from ../A2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg merge
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg commit -m "commit test"
bar should remain deleted.
  $ hg manifest --debug
  f9b0e817f6a48de3564c6b2957687c5e7297c5a0 644   foo

  $ cd ..