view tests/test-pathconflicts-update.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

Path conflict checking is currently disabled by default because of issue5716.
Turn it on for this test.

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > merge.checkpathconflicts=True
  > EOF

  $ hg init repo
  $ cd repo
  $ echo base > base
  $ hg add base
  $ hg commit -m "base"
  $ hg bookmark -i base
  $ mkdir a
  $ echo 1 > a/b
  $ hg add a/b
  $ hg commit -m "file"
  $ hg bookmark -i file
  $ echo 2 > a/b
  $ hg commit -m "file2"
  $ hg bookmark -i file2
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkdir a
#if symlink
  $ ln -s c a/b
#else
  $ touch a/b
#endif
  $ hg add a/b
  $ hg commit -m "link"
  created new head
  $ hg bookmark -i link
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkdir -p a/b/c
  $ echo 2 > a/b/c/d
  $ hg add a/b/c/d
  $ hg commit -m "dir"
  created new head
  $ hg bookmark -i dir

Update - local file conflicts with remote directory:

  $ hg up -q 0
  $ mkdir a
  $ echo 9 > a/b
  $ hg up dir
  a/b: untracked file conflicts with directory
  abort: untracked files in working directory differ from files in requested revision
  [255]
  $ hg up dir --config merge.checkunknown=warn
  a/b: replacing untracked file
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark dir)
  $ cat a/b.orig
  9
  $ rm a/b.orig

Update - local symlink conflicts with remote directory:

  $ hg up -q 0
  $ mkdir a
#if symlink
  $ ln -s x a/b
#else
  $ touch a/b
#endif
  $ hg up dir
  a/b: untracked file conflicts with directory
  abort: untracked files in working directory differ from files in requested revision
  [255]
  $ hg up dir --config merge.checkunknown=warn
  a/b: replacing untracked file
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark dir)
#if symlink
  $ readlink.py a/b.orig
  a/b.orig -> x
#endif
  $ rm a/b.orig

Update - local directory conflicts with remote file

  $ hg up -q 0
  $ mkdir -p a/b/c
  $ echo 9 > a/b/c/d
  $ hg up file
  a/b: untracked directory conflicts with file
  abort: untracked files in working directory differ from files in requested revision
  [255]
  $ hg up file --config merge.checkunknown=warn
  a/b: replacing untracked files in directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark file)
  $ cat a/b
  1
  $ test -d a/b.orig
  $ rm -rf a/b.orig

Update - local directory conflicts with remote symlink

  $ hg up -q 0
  $ mkdir -p a/b/c
  $ echo 9 > a/b/c/d
  $ hg up link
  a/b: untracked directory conflicts with file
  abort: untracked files in working directory differ from files in requested revision
  [255]
  $ hg up link --config merge.checkunknown=warn
  a/b: replacing untracked files in directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark link)
#if symlink
  $ readlink.py a/b
  a/b -> c
#endif
  $ test -d a/b.orig
  $ rm -rf a/b.orig

Update - local renamed file conflicts with remote directory

  $ hg up -q 0
  $ hg mv base a
  $ hg status -C
  A a
    base
  R base
  $ hg up --check dir
  abort: uncommitted changes
  [255]
  $ hg up dir
  a: path conflict - a file or link has the same name as a directory
  the local file has been renamed to a~d20a80d4def3
  resolve manually then use 'hg resolve --mark a'
  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  (activating bookmark dir)
  [1]
  $ hg status -C
  A a~d20a80d4def3
    base
  R base
  $ hg resolve --list
  P a
  $ hg up --clean -q 0

Update clean - local directory conflicts with changed remote file

  $ hg up -q file
  $ rm a/b
  $ mkdir a/b
  $ echo 9 > a/b/c
  $ hg up file2 --check --config merge.checkunknown=warn
  abort: uncommitted changes
  [255]
  $ hg up file2 --clean
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark file2)