view tests/test-narrow-clone-no-ellipsis.t @ 39561:d06834e0f48e

wireprotov2peer: stream decoded responses

Previously, wire protocol version 2 would buffer all response data.
Only once all data was received did we CBOR decode it and resolve
the future associated with the command. This was obviously not
desirable. In future commits that introduce large response payloads,
this caused significant memory bloat and slowed down client
operations due to waiting on the server.

This commit refactors the response handling code so that response
data can be streamed.

Command response objects now contain a buffered CBOR decoder. As
new data arrives, it is fed into the decoder. Decoded objects are
made available to the generator as they are decoded.

Because there is a separate thread processing incoming frames and
feeding data into the response object, there is the potential for
race conditions when mutating response objects. So a lock has been
added to guard access to critical state variables.

Because the generator emitting decoded objects needs to wait on
those objects to become available, we've added an Event for the
generator to wait on so it doesn't busy loop. This does mean
there is the potential for deadlocks. And I'm pretty sure they can
occur in some scenarios. We already have a handful of TODOs around
this. But I've added some more. Fixing this will likely require
moving the background thread receiving frames into clienthandler.
We likely would have done this anyway when implementing the client
bits for the SSH transport.

Test output changes because the initial CBOR map holding the overall
response state is now always handled internally by the response
object.

Differential Revision: https://phab.mercurial-scm.org/D4474

  $ . "$TESTDIR/narrow-library.sh"

  $ hg init master
  $ cd master
  $ mkdir dir
  $ mkdir dir/src
  $ cd dir/src
  $ for x in `$TESTDIR/seq.py 20`; do echo $x > "f$x"; hg add "f$x"; hg commit -m "Commit src $x"; done
  $ cd ..
  $ mkdir tests
  $ cd tests
  $ for x in `$TESTDIR/seq.py 20`; do echo $x > "t$x"; hg add "t$x"; hg commit -m "Commit test $x"; done
  $ cd ../../..

narrow clone a file, f10

  $ hg clone --narrow ssh://user@dummy/master narrow --noupdate --include "dir/src/f10"
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 40 changesets with 1 changes to 1 files
  new changesets *:* (glob)
  $ cd narrow
  $ cat .hg/requires | grep -v generaldelta
  dotencode
  fncache
  narrowhg-experimental
  revlogv1
  store
  testonly-simplestore (reposimplestore !)

  $ hg tracked
  I path:dir/src/f10
  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ find * | sort
  dir
  dir/src
  dir/src/f10
  $ cat dir/src/f10
  10

  $ cd ..

narrow clone a directory, tests/, except tests/t19

  $ hg clone --narrow ssh://user@dummy/master narrowdir --noupdate --include "dir/tests/" --exclude "dir/tests/t19"
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 40 changesets with 19 changes to 19 files
  new changesets *:* (glob)
  $ cd narrowdir
  $ hg tracked
  I path:dir/tests
  X path:dir/tests/t19
  $ hg update
  19 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ find * | sort
  dir
  dir/tests
  dir/tests/t1
  dir/tests/t10
  dir/tests/t11
  dir/tests/t12
  dir/tests/t13
  dir/tests/t14
  dir/tests/t15
  dir/tests/t16
  dir/tests/t17
  dir/tests/t18
  dir/tests/t2
  dir/tests/t20
  dir/tests/t3
  dir/tests/t4
  dir/tests/t5
  dir/tests/t6
  dir/tests/t7
  dir/tests/t8
  dir/tests/t9

  $ cd ..

narrow clone everything but a directory (tests/)

  $ hg clone --narrow ssh://user@dummy/master narrowroot --noupdate --exclude "dir/tests"
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 40 changesets with 20 changes to 20 files
  new changesets *:* (glob)
  $ cd narrowroot
  $ hg tracked
  I path:.
  X path:dir/tests
  $ hg update
  20 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ find * | sort
  dir
  dir/src
  dir/src/f1
  dir/src/f10
  dir/src/f11
  dir/src/f12
  dir/src/f13
  dir/src/f14
  dir/src/f15
  dir/src/f16
  dir/src/f17
  dir/src/f18
  dir/src/f19
  dir/src/f2
  dir/src/f20
  dir/src/f3
  dir/src/f4
  dir/src/f5
  dir/src/f6
  dir/src/f7
  dir/src/f8
  dir/src/f9

  $ cd ..

Testing the --narrowspec flag to clone

  $ cat >> narrowspecs <<EOF
  > %include foo
  > [include]
  > path:dir/tests/
  > path:dir/src/f12
  > EOF

  $ hg clone ssh://user@dummy/master specfile --narrowspec narrowspecs
  reading narrowspec from '$TESTTMP/narrowspecs'
  abort: cannot specify other files using '%include' in narrowspec
  [255]

  $ cat > narrowspecs <<EOF
  > [include]
  > path:dir/tests/
  > path:dir/src/f12
  > EOF

  $ hg clone ssh://user@dummy/master specfile --narrowspec narrowspecs
  reading narrowspec from '$TESTTMP/narrowspecs'
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 40 changesets with 21 changes to 21 files
  new changesets 681085829a73:26ce255d5b5d
  updating to branch default
  21 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd specfile
  $ hg tracked
  I path:dir/src/f12
  I path:dir/tests
  $ cd ..