view tests/test-issue1306.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.

https://bz.mercurial-scm.org/1306

Initialize remote repo with branches:

  $ hg init remote
  $ cd remote

  $ echo a > a
  $ hg ci -Ama
  adding a

  $ hg branch br
  marked working directory as branch br
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -Amb

  $ echo c > c
  $ hg ci -Amc
  adding c

  $ hg log
  changeset:   2:ae3d9c30ec50
  branch:      br
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:3f7f930ca414
  branch:      br
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  

  $ cd ..

Try cloning -r branch:

  $ hg clone -rbr remote local1
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  updating to branch br
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R local1 parents
  changeset:   2:ae3d9c30ec50
  branch:      br
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  

Try cloning -rother clone#branch:

  $ hg clone -r0 remote#br local2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R local2 parents
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  

Try cloning -r1 clone#branch:

  $ hg clone -r1 remote#br local3
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  updating to branch br
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R local3 parents
  changeset:   1:3f7f930ca414
  branch:      br
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b