tests/test-relink.t

wireproto: introduce a reactor for client-side state

We have a nice state machine of sorts for reacting to server-side
events. Now it is time to implement the client equivalent.

We introduce a "clientreactor." It allows callers to request
that commands be issued. It has multiple modes of operation to
reflect what the underlying transport supports. e.g. for SSH,
we can perform wire sends immediately but for HTTP we need to
buffer sends until all command requests are received. In addition,
SSH allows sending multiple requests as long as the connection is
open. But HTTP/1.1 only allows sending request data once.

For SSH, we'll have one reactor per connection. For HTTP, we'll
have one reactor per HTTP request. But because code that calls
wire protocol commands should not be aware of how the underlying
transport works, this will all be abstracted away by the peer
interface.

Our crude HTTP peer has been updated to use the reactor instead
of formulating frames directly. No behavior should have changed
here and tests seem to confirm that.

Basic unit tests for the reactor behavior have been added.

Differential Revision: https://phab.mercurial-scm.org/D3223

#require hardlink

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "relink=" >> $HGRCPATH

  $ fix_path() {
  >     tr '\\' /
  > }

  $ cat > arelinked.py <<EOF
  > from __future__ import absolute_import, print_function
  > import os
  > import sys
  > from mercurial import util
  > path1, path2 = sys.argv[1:3]
  > if util.samefile(path1, path2):
  >     print('%s == %s' % (path1, path2))
  > else:
  >     print('%s != %s' % (path1, path2))
  > EOF


create source repository

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ echo b > b
  $ hg ci -Am addfile
  adding a
  adding b
  $ cat "$TESTDIR/binfile.bin" >> a
  $ cat "$TESTDIR/binfile.bin" >> b
  $ hg ci -Am changefiles

make another commit to create files larger than 1 KB to test
formatting of final byte count

  $ cat "$TESTDIR/binfile.bin" >> a
  $ cat "$TESTDIR/binfile.bin" >> b
  $ hg ci -m anotherchange

don't sit forever trying to double-lock the source repo

  $ hg relink .
  relinking $TESTTMP/repo/.hg/store to $TESTTMP/repo/.hg/store
  there is nothing to relink


Test files are read in binary mode

  $ $PYTHON -c "open('.hg/store/data/dummy.i', 'wb').write(b'a\r\nb\n')"
  $ cd ..


clone and pull to break links

  $ hg clone --pull -r0 repo clone
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 2 changes to 2 files
  new changesets 008c0c271c47
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd clone
  $ hg pull -q
  $ echo b >> b
  $ hg ci -m changeb
  created new head
  $ $PYTHON -c "open('.hg/store/data/dummy.i', 'wb').write(b'a\nb\r\n')"


relink

#if no-reposimplestore

  $ hg relink --debug --config progress.debug=true | fix_path
  relinking $TESTTMP/repo/.hg/store to $TESTTMP/clone/.hg/store
  tip has 2 files, estimated total number of files: 3
  collecting: 00changelog.i 1/3 files (33.33%)
  collecting: 00manifest.i 2/3 files (66.67%)
  collecting: a.i 3/3 files (100.00%)
  collecting: b.i 4/3 files (133.33%)
  collecting: dummy.i 5/3 files (166.67%)
  collected 5 candidate storage files
  not linkable: 00changelog.i
  not linkable: 00manifest.i
  pruning: data/a.i 3/5 files (60.00%)
  not linkable: data/b.i
  pruning: data/dummy.i 5/5 files (100.00%)
  pruned down to 2 probably relinkable files
  relinking: data/a.i 1/2 files (50.00%)
  not linkable: data/dummy.i
  relinked 1 files (1.36 KB reclaimed)
  $ cd ..


check hardlinks

  $ $PYTHON arelinked.py repo/.hg/store/data/a.i clone/.hg/store/data/a.i
  repo/.hg/store/data/a.i == clone/.hg/store/data/a.i
  $ $PYTHON arelinked.py repo/.hg/store/data/b.i clone/.hg/store/data/b.i
  repo/.hg/store/data/b.i != clone/.hg/store/data/b.i

#endif