tests/test-push-hook-lock.t

store: replace invocation of "getsize()" by "vfs.stat()"

This patch replaces invocation of "getsize()", which calls "os.stat()"
internally, by "vfs.stat()".

The object referred by "self.rawvfs" is used internally by
"_fncachevfs" and doesn't encode filename for each file API invocation.

This patch invokes "os.stat()" via "self.rawvfs" to avoid redundant
filename encoding: invocation of "os.stat()" via "self.vfs" hides
filename encoding and encoding result from caller, so it is not
appropriate, when both encoded and non-encoded filenames should be
yield.

Even though changeset b42b0729744d improved stream_out performance by
"self.pathsep + path", this patch replaces it by
"os.path.join(self.base, path)" of vfs. So, this may increase cost to
join path components.

But this shouldn't have large impact, because:

  - such cost is much less than cost of "os.stat()" which causes
    system call invocation

  - "datafiles()" of store object is invoked only for "hg manifest
    --all" or "hg verify" which are both heavy functions

  $ hg init 1

  $ echo '[ui]' >> 1/.hg/hgrc
  $ echo 'timeout = 10' >> 1/.hg/hgrc

  $ echo foo > 1/foo
  $ hg --cwd 1 ci -A -m foo
  adding foo

  $ hg clone 1 2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg clone 2 3
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo '[hooks]' >> 2/.hg/hgrc
  $ echo 'changegroup.push = hg push -qf ../1' >> 2/.hg/hgrc

  $ echo bar >> 3/foo
  $ hg --cwd 3 ci -m bar

  $ hg --cwd 3 push ../2
  pushing to ../2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files