view tests/test-convert-svn-sink.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

#require svn13

  $ svnupanddisplay()
  > {
  >     (
  >        cd $1;
  >        svn up -q;
  >        svn st -v | sed 's/  */ /g' | sort
  >        limit=''
  >        if [ $2 -gt 0 ]; then
  >            limit="--limit=$2"
  >        fi
  >        svn log --xml -v $limit | $PYTHON "$TESTDIR/svnxml.py"
  >     )
  > }

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert =
  > EOF

  $ hg init a

Add

  $ echo a > a/a
  $ mkdir -p a/d1/d2
  $ echo b > a/d1/d2/b
  $ hg --cwd a ci -d '0 0' -A -m 'add a file'
  adding a
  adding d1/d2/b

Modify

  $ svn-safe-append.py a a/a
  $ hg --cwd a ci -d '1 0' -m 'modify a file'
  $ hg --cwd a tip -q
  1:e0e2b8a9156b

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn repository 'a-hg'
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  1 add a file
  0 modify a file
  $ svnupanddisplay a-hg-wc 2
   2 1 test d1
   2 1 test d1/d2
   2 1 test d1/d2/b
   2 2 test .
   2 2 test a
  revision: 2
  author: test
  msg: modify a file
   M /a
  revision: 1
  author: test
  msg: add a file
   A /a
   A /d1
   A /d1/d2
   A /d1/d2/b
  $ ls a a-hg-wc
  a:
  a
  d1
  
  a-hg-wc:
  a
  d1
  $ cmp a/a a-hg-wc/a

Rename

  $ hg --cwd a mv a b
  $ hg --cwd a ci -d '2 0' -m 'rename a file'
  $ hg --cwd a tip -q
  2:eb5169441d43

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 rename a file
  $ svnupanddisplay a-hg-wc 1
   3 1 test d1
   3 1 test d1/d2
   3 1 test d1/d2/b
   3 3 test .
   3 3 test b
  revision: 3
  author: test
  msg: rename a file
   D /a
   A /b (from /a@2)
  $ ls a a-hg-wc
  a:
  b
  d1
  
  a-hg-wc:
  b
  d1

Copy

  $ hg --cwd a cp b c

  $ hg --cwd a ci -d '3 0' -m 'copy a file'
  $ hg --cwd a tip -q
  3:60effef6ab48

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 copy a file
  $ svnupanddisplay a-hg-wc 1
   4 1 test d1
   4 1 test d1/d2
   4 1 test d1/d2/b
   4 3 test b
   4 4 test .
   4 4 test c
  revision: 4
  author: test
  msg: copy a file
   A /c (from /b@3)
  $ ls a a-hg-wc
  a:
  b
  c
  d1
  
  a-hg-wc:
  b
  c
  d1

  $ hg --cwd a rm b

Remove

  $ hg --cwd a ci -d '4 0' -m 'remove a file'
  $ hg --cwd a tip -q
  4:87bbe3013fb6

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 remove a file
  $ svnupanddisplay a-hg-wc 1
   5 1 test d1
   5 1 test d1/d2
   5 1 test d1/d2/b
   5 4 test c
   5 5 test .
  revision: 5
  author: test
  msg: remove a file
   D /b
  $ ls a a-hg-wc
  a:
  c
  d1
  
  a-hg-wc:
  c
  d1

Executable

#if execbit
  $ chmod +x a/c
#else
  $ echo fake >> a/c
#endif
  $ hg --cwd a ci -d '5 0' -m 'make a file executable'
#if execbit
  $ hg --cwd a tip -q
  5:ff42e473c340
#else
  $ hg --cwd a tip -q
  5:817a700c8cf1
#endif

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 make a file executable
  $ svnupanddisplay a-hg-wc 1
   6 1 test d1
   6 1 test d1/d2
   6 1 test d1/d2/b
   6 6 test .
   6 6 test c
  revision: 6
  author: test
  msg: make a file executable
   M /c
#if execbit
  $ test -x a-hg-wc/c
#endif

#if symlink

Symlinks

  $ ln -s a/missing a/link
  $ hg --cwd a commit -Am 'add symlink'
  adding link
  $ hg --cwd a mv link newlink
  $ hg --cwd a commit -m 'move symlink'
  $ hg convert -d svn a a-svnlink
  initializing svn repository 'a-svnlink'
  initializing svn working copy 'a-svnlink-wc'
  scanning source...
  sorting...
  converting...
  7 add a file
  6 modify a file
  5 rename a file
  4 copy a file
  3 remove a file
  2 make a file executable
  1 add symlink
  0 move symlink
  $ svnupanddisplay a-svnlink-wc 1
   8 1 test d1
   8 1 test d1/d2
   8 1 test d1/d2/b
   8 6 test c
   8 8 test .
   8 8 test newlink
  revision: 8
  author: test
  msg: move symlink
   D /link
   A /newlink (from /link@7)

Make sure our changes don't affect the rest of the test cases

  $ hg --cwd a up 5
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg --cwd a --config extensions.strip= strip -r 6
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/bd4f7b7a7067-ed505e42-backup.hg

#endif

Convert with --full adds and removes files that didn't change

  $ touch a/f
  $ hg -R a ci -Aqmf
  $ echo "rename c d" > filemap
  $ hg convert -d svn a --filemap filemap --full
  assuming destination a-hg
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 f
  $ svnupanddisplay a-hg-wc 1
   7 7 test .
   7 7 test d
   7 7 test f
  revision: 7
  author: test
  msg: f
   D /c
   A /d
   D /d1
   A /f

  $ rm -rf a a-hg a-hg-wc


Executable in new directory

  $ hg init a

  $ mkdir a/d1
  $ echo a > a/d1/a
#if execbit
  $ chmod +x a/d1/a
#else
  $ echo fake >> a/d1/a
#endif
  $ hg --cwd a ci -d '0 0' -A -m 'add executable file in new directory'
  adding d1/a

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn repository 'a-hg'
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 add executable file in new directory
  $ svnupanddisplay a-hg-wc 1
   1 1 test .
   1 1 test d1
   1 1 test d1/a
  revision: 1
  author: test
  msg: add executable file in new directory
   A /d1
   A /d1/a
#if execbit
  $ test -x a-hg-wc/d1/a
#endif

Copy to new directory

  $ mkdir a/d2
  $ hg --cwd a cp d1/a d2/a
  $ hg --cwd a ci -d '1 0' -A -m 'copy file to new directory'

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  0 copy file to new directory
  $ svnupanddisplay a-hg-wc 1
   2 1 test d1
   2 1 test d1/a
   2 2 test .
   2 2 test d2
   2 2 test d2/a
  revision: 2
  author: test
  msg: copy file to new directory
   A /d2
   A /d2/a (from /d1/a@1)

Branchy history

  $ hg init b
  $ echo base > b/b
  $ hg --cwd b ci -d '0 0' -Ambase
  adding b

  $ svn-safe-append.py left-1 b/b
  $ echo left-1 > b/left-1
  $ hg --cwd b ci -d '1 0' -Amleft-1
  adding left-1

  $ svn-safe-append.py left-2 b/b
  $ echo left-2 > b/left-2
  $ hg --cwd b ci -d '2 0' -Amleft-2
  adding left-2

  $ hg --cwd b up 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

  $ svn-safe-append.py right-1 b/b
  $ echo right-1 > b/right-1
  $ hg --cwd b ci -d '3 0' -Amright-1
  adding right-1
  created new head

  $ svn-safe-append.py right-2 b/b
  $ echo right-2 > b/right-2
  $ hg --cwd b ci -d '4 0' -Amright-2
  adding right-2

  $ hg --cwd b up -C 2
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg --cwd b merge
  merging b
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  2 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg --cwd b revert -r 2 b
  $ hg --cwd b resolve -m b
  (no more unresolved files)
  $ hg --cwd b ci -d '5 0' -m 'merge'

Expect 4 changes

  $ hg convert -d svn b
  assuming destination b-hg
  initializing svn repository 'b-hg'
  initializing svn working copy 'b-hg-wc'
  scanning source...
  sorting...
  converting...
  5 base
  4 left-1
  3 left-2
  2 right-1
  1 right-2
  0 merge

  $ svnupanddisplay b-hg-wc 0
   4 2 test left-1
   4 3 test b
   4 3 test left-2
   4 4 test .
   4 4 test right-1
   4 4 test right-2
  revision: 4
  author: test
  msg: merge
   A /right-1
   A /right-2
  revision: 3
  author: test
  msg: left-2
   M /b
   A /left-2
  revision: 2
  author: test
  msg: left-1
   M /b
   A /left-1
  revision: 1
  author: test
  msg: base
   A /b

Tags are not supported, but must not break conversion

  $ rm -rf a a-hg a-hg-wc
  $ hg init a
  $ echo a > a/a
  $ hg --cwd a ci -d '0 0' -A -m 'Add file a'
  adding a
  $ hg --cwd a tag -d '1 0' -m 'Tagged as v1.0' v1.0

  $ hg convert -d svn a
  assuming destination a-hg
  initializing svn repository 'a-hg'
  initializing svn working copy 'a-hg-wc'
  scanning source...
  sorting...
  converting...
  1 Add file a
  0 Tagged as v1.0
  writing Subversion tags is not yet implemented
  $ svnupanddisplay a-hg-wc 2
   2 1 test a
   2 2 test .
   2 2 test .hgtags
  revision: 2
  author: test
  msg: Tagged as v1.0
   A /.hgtags
  revision: 1
  author: test
  msg: Add file a
   A /a
  $ rm -rf a a-hg a-hg-wc