view tests/test-copy.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

  $ mkdir part1
  $ cd part1

  $ hg init
  $ echo a > a
  $ hg add a
  $ hg commit -m "1"
  $ hg status
  $ hg copy a b
  $ hg --config ui.portablefilenames=abort copy a con.xml
  abort: filename contains 'con', which is reserved on Windows: con.xml
  [255]
  $ hg status
  A b
  $ hg sum
  parent: 0:c19d34741b0a tip
   1
  branch: default
  commit: 1 copied
  update: (current)
  phases: 1 draft
  $ hg --debug commit -m "2"
  committing files:
  b
   b: copy a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
  committing manifest
  committing changelog
  updating the branch cache
  committed changeset 1:93580a2c28a50a56f63526fb305067e6fbf739c4

we should see two history entries

  $ hg history -v
  changeset:   1:93580a2c28a5
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       b
  description:
  2
  
  
  changeset:   0:c19d34741b0a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       a
  description:
  1
  
  

we should see one log entry for a

  $ hg log a
  changeset:   0:c19d34741b0a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  

this should show a revision linked to changeset 0

  $ hg debugindex a
     rev linkrev nodeid       p1           p2
       0       0 b789fdd96dc2 000000000000 000000000000

we should see one log entry for b

  $ hg log b
  changeset:   1:93580a2c28a5
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  

this should show a revision linked to changeset 1

  $ hg debugindex b
     rev linkrev nodeid       p1           p2
       0       1 37d9b5d994ea 000000000000 000000000000

this should show the rename information in the metadata

  $ hg debugdata b 0 | head -3 | tail -2
  copy: a
  copyrev: b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3

#if reporevlogstore
  $ md5sum.py .hg/store/data/b.i
  44913824c8f5890ae218f9829535922e  .hg/store/data/b.i
#endif
  $ hg cat b > bsum
  $ md5sum.py bsum
  60b725f10c9c85c70d97880dfe8191b3  bsum
  $ hg cat a > asum
  $ md5sum.py asum
  60b725f10c9c85c70d97880dfe8191b3  asum
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 2 changes to 2 files

  $ cd ..


  $ mkdir part2
  $ cd part2

  $ hg init
  $ echo foo > foo
should fail - foo is not managed
  $ hg mv foo bar
  foo: not copying - file is not managed
  abort: no files to copy
  [255]
  $ hg st -A
  ? foo
  $ hg add foo
dry-run; print a warning that this is not a real copy; foo is added
  $ hg mv --dry-run foo bar
  foo has not been committed yet, so no copy data will be stored for bar.
  $ hg st -A
  A foo
should print a warning that this is not a real copy; bar is added
  $ hg mv foo bar
  foo has not been committed yet, so no copy data will be stored for bar.
  $ hg st -A
  A bar
should print a warning that this is not a real copy; foo is added
  $ hg cp bar foo
  bar has not been committed yet, so no copy data will be stored for foo.
  $ hg rm -f bar
  $ rm bar
  $ hg st -A
  A foo
  $ hg commit -m1

moving a missing file
  $ rm foo
  $ hg mv foo foo3
  foo: deleted in working directory
  foo3 does not exist!
  $ hg up -qC .

copy --after to a nonexistent target filename
  $ hg cp -A foo dummy
  foo: not recording copy - dummy does not exist
  [1]

dry-run; should show that foo is clean
  $ hg copy --dry-run foo bar
  $ hg st -A
  C foo
should show copy
  $ hg copy foo bar
  $ hg st -C
  A bar
    foo

shouldn't show copy
  $ hg commit -m2
  $ hg st -C

should match
  $ hg debugindex foo
     rev linkrev nodeid       p1           p2
       0       0 2ed2a3912a0b 000000000000 000000000000
  $ hg debugrename bar
  bar renamed from foo:2ed2a3912a0b24502043eae84ee4b279c18b90dd

  $ echo bleah > foo
  $ echo quux > bar
  $ hg commit -m3

should not be renamed
  $ hg debugrename bar
  bar not renamed

  $ hg copy -f foo bar
should show copy
  $ hg st -C
  M bar
    foo

XXX: filtering lfilesrepo.status() in 3.3-rc causes the copy source to not be
displayed.
  $ hg st -C --config extensions.largefiles=
  The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
  M bar
    foo

  $ hg commit -m3

should show no parents for tip
  $ hg debugindex bar
     rev linkrev nodeid       p1           p2
       0       1 7711d36246cc 000000000000 000000000000
       1       2 bdf70a2b8d03 7711d36246cc 000000000000
       2       3 b2558327ea8d 000000000000 000000000000
should match
  $ hg debugindex foo
     rev linkrev nodeid       p1           p2
       0       0 2ed2a3912a0b 000000000000 000000000000
       1       2 dd12c926cf16 2ed2a3912a0b 000000000000
  $ hg debugrename bar
  bar renamed from foo:dd12c926cf165e3eb4cf87b084955cb617221c17

should show no copies
  $ hg st -C

copy --after on an added file
  $ cp bar baz
  $ hg add baz
  $ hg cp -A bar baz
  $ hg st -C
  A baz
    bar

foo was clean:
  $ hg st -AC foo
  C foo
Trying to copy on top of an existing file fails,
  $ hg copy -A bar foo
  foo: not overwriting - file already committed
  ('hg copy --after --force' to replace the file by recording a copy)
  [1]
same error without the --after, so the user doesn't have to go through
two hints:
  $ hg copy bar foo
  foo: not overwriting - file already committed
  ('hg copy --force' to replace the file by recording a copy)
  [1]
but it's considered modified after a copy --after --force
  $ hg copy -Af bar foo
  $ hg st -AC foo
  M foo
    bar
The hint for a file that exists but is not in file history doesn't
mention --force:
  $ touch xyzzy
  $ hg cp bar xyzzy
  xyzzy: not overwriting - file exists
  ('hg copy --after' to record the copy)
  [1]

  $ cd ..