view tests/test-convert-hg-source.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

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert=
  > [convert]
  > hg.saverev=False
  > EOF
  $ hg init orig
  $ cd orig
  $ echo foo > foo
  $ echo bar > bar
  $ hg ci -qAm 'add foo bar' -d '0 0'
  $ echo >> foo
  $ hg ci -m 'change foo' -d '1 0'
  $ hg up -qC 0
  $ hg copy --after --force foo bar
  $ hg copy foo baz
  $ hg ci -m 'make bar and baz copies of foo' -d '2 0'
  created new head

Test that template can print all file copies (issue4362)
  $ hg log -r . --template "{file_copies % ' File: {file_copy}\n'}"
   File: bar (foo)
   File: baz (foo)

  $ hg bookmark premerge1
  $ hg merge -r 1
  merging baz and foo to baz
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merge local copy' -d '3 0'
  $ hg up -C 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (leaving bookmark premerge1)
  $ hg bookmark premerge2
  $ hg merge 2
  merging foo and baz to baz
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merge remote copy' -d '4 0'
  created new head

Make and delete some tags

  $ hg tag that
  $ hg tag --remove that
  $ hg tag this

#if execbit
  $ chmod +x baz
#else
  $ echo some other change to make sure we get a rev 5 > baz
#endif
  $ hg ci -m 'mark baz executable' -d '5 0'
  $ cd ..
  $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  initializing destination new repository
  scanning source...
  sorting...
  converting...
  8 add foo bar
  7 change foo
  6 make bar and baz copies of foo
  5 merge local copy
  4 merge remote copy
  3 Added tag that for changeset 88586c4e9f02
  2 Removed tag that
  1 Added tag this for changeset c56a7f387039
  0 mark baz executable
  updating bookmarks
  $ cd new
  $ hg out ../orig
  comparing with ../orig
  searching for changes
  no changes found
  [1]
#if execbit
  $ hg bookmarks
     premerge1                 3:973ef48a98a4
     premerge2                 8:91d107c423ba
#else
Different hash because no x bit
  $ hg bookmarks
     premerge1                 3:973ef48a98a4
     premerge2                 8:3537b15eaaca
#endif

Test that redoing a convert results in an identical graph
  $ cd ../
  $ rm new/.hg/shamap
  $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  scanning source...
  sorting...
  converting...
  8 add foo bar
  7 change foo
  6 make bar and baz copies of foo
  5 merge local copy
  4 merge remote copy
  3 Added tag that for changeset 88586c4e9f02
  2 Removed tag that
  1 Added tag this for changeset c56a7f387039
  0 mark baz executable
  updating bookmarks
  $ hg -R new log -G -T '{rev} {desc}'
  o  8 mark baz executable
  |
  o  7 Added tag this for changeset c56a7f387039
  |
  o  6 Removed tag that
  |
  o  5 Added tag that for changeset 88586c4e9f02
  |
  o    4 merge remote copy
  |\
  +---o  3 merge local copy
  | |/
  | o  2 make bar and baz copies of foo
  | |
  o |  1 change foo
  |/
  o  0 add foo bar
  

check shamap LF and CRLF handling

  $ cat > rewrite.py <<EOF
  > import sys
  > # Interlace LF and CRLF
  > lines = [(l.rstrip() + ((i % 2) and b'\n' or b'\r\n'))
  >          for i, l in enumerate(open(sys.argv[1], 'rb'))]
  > open(sys.argv[1], 'wb').write(b''.join(lines))
  > EOF
  $ $PYTHON rewrite.py new/.hg/shamap
  $ cd orig
  $ hg up -qC 1
  $ echo foo >> foo
  $ hg ci -qm 'change foo again'
  $ hg up -qC 2
  $ echo foo >> foo
  $ hg ci -qm 'change foo again again'
  $ cd ..
  $ hg convert --datesort orig new 2>&1 | grep -v 'subversion python bindings could not be loaded'
  scanning source...
  sorting...
  converting...
  1 change foo again again
  0 change foo again
  updating bookmarks

init broken repository

  $ hg init broken
  $ cd broken
  $ echo a >> a
  $ echo b >> b
  $ hg ci -qAm init
  $ echo a >> a
  $ echo b >> b
  $ hg copy b c
  $ hg ci -qAm changeall
  $ hg up -qC 0
  $ echo bc >> b
  $ hg ci -m changebagain
  created new head
  $ HGMERGE=internal:local hg -q merge
  $ hg ci -m merge
  $ hg mv b d
  $ hg ci -m moveb

break it

#if reporevlogstore
  $ rm .hg/store/data/b.*
#endif
#if reposimplestore
  $ rm .hg/store/data/b/*
#endif
  $ cd ..
  $ hg --config convert.hg.ignoreerrors=True convert broken fixed
  initializing destination fixed repository
  scanning source...
  sorting...
  converting...
  4 init
  ignoring: data/b.i@1e88685f5dde: no match found (reporevlogstore !)
  ignoring: data/b/index@1e88685f5dde: no node (reposimplestore !)
  3 changeall
  2 changebagain
  1 merge
  0 moveb
  $ hg -R fixed verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 5 changes to 3 files

manifest -r 0

  $ hg -R fixed manifest -r 0
  a

manifest -r tip

  $ hg -R fixed manifest -r tip
  a
  c
  d