tests/test-ssh-clone-r.t

bundle2: implement consume() API on unbundlepart

We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.

A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.

In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.

The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:

! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)

Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.

Differential Revision: https://phab.mercurial-scm.org/D1388

This test tries to exercise the ssh functionality with a dummy script

creating 'remote' repo

  $ hg init remote
  $ cd remote
  $ hg unbundle "$TESTDIR/bundles/remote.hg"
  adding changesets
  adding manifests
  adding file changes
  added 9 changesets with 7 changes to 4 files (+1 heads)
  new changesets bfaf4b5cbf01:916f1afdef90
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd ..

clone remote via stream

  $ for i in 0 1 2 3 4 5 6 7 8; do
  >    hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" --stream -r "$i" ssh://user@dummy/remote test-"$i"
  >    if cd test-"$i"; then
  >       hg verify
  >       cd ..
  >    fi
  > done
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets bfaf4b5cbf01
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 1 changesets, 1 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets bfaf4b5cbf01:21f32785131f
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 2 changesets, 2 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 1 files
  new changesets bfaf4b5cbf01:4ce51a113780
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 3 changesets, 3 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 1 files
  new changesets bfaf4b5cbf01:93ee6ab32777
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 4 changesets, 4 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  new changesets bfaf4b5cbf01:c70afb1ee985
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 2 changesets, 2 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 1 files
  new changesets bfaf4b5cbf01:f03ae5a9b979
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 3 changesets, 3 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 5 changes to 2 files
  new changesets bfaf4b5cbf01:095cb14b1b4d
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 4 changesets, 5 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 5 changesets with 6 changes to 3 files
  new changesets bfaf4b5cbf01:faa2e4234c7a
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  3 files, 5 changesets, 6 total revisions
  adding changesets
  adding manifests
  adding file changes
  added 5 changesets with 5 changes to 2 files
  new changesets bfaf4b5cbf01:916f1afdef90
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  2 files, 5 changesets, 5 total revisions
  $ cd test-8
  $ hg pull ../test-7
  pulling from ../test-7
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 2 changes to 3 files (+1 heads)
  new changesets c70afb1ee985:faa2e4234c7a
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  4 files, 9 changesets, 7 total revisions
  $ cd ..
  $ cd test-1
  $ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" -r 4 ssh://user@dummy/remote
  pulling from ssh://user@dummy/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets c70afb1ee985
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 3 changesets, 2 total revisions
  $ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
  pulling from ssh://user@dummy/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 5 changes to 4 files
  new changesets 4ce51a113780:916f1afdef90
  (run 'hg update' to get a working copy)
  $ cd ..
  $ cd test-2
  $ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" -r 5 ssh://user@dummy/remote
  pulling from ssh://user@dummy/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 0 changes to 0 files (+1 heads)
  new changesets c70afb1ee985:f03ae5a9b979
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 5 changesets, 3 total revisions
  $ hg pull -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote
  pulling from ssh://user@dummy/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 4 files
  new changesets 93ee6ab32777:916f1afdef90
  (run 'hg update' to get a working copy)
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  4 files, 9 changesets, 7 total revisions

  $ cd ..