view tests/test-pull-permission.t @ 14164:cb98fed52495

discovery: add new set-based discovery

Adds a new discovery method based on repeatedly sampling the still
undecided subset of the local node graph to determine the set of nodes
common to both the client and the server.

For small differences between client and server, it uses about the same
or slightly fewer roundtrips than the old tree-based discovery. For
larger differences, it typically reduces the number of roundtrips
drastically (from 150 to 4, for instance).

The old discovery code now lives in treediscovery.py, the new code is
in setdiscovery.py.

Still missing is a hook for extensions to contribute nodes to the
initial sample. For instance, Augie's remotebranches could contribute
the last known state of the server's heads.

Credits for the actual sampler and computing common heads instead of
bases go to Benoit Boissinot.

  $ hg init a
  $ cd a
  $ echo foo > b
  $ hg add b
  $ hg ci -m "b"

  $ chmod -w .hg/store

  $ cd ..

  $ hg clone a b
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ chmod +w a/.hg/store # let test clean up

  $ cd b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 1 changesets, 1 total revisions