Mercurial > hg
view tests/test-mq-qpush-exact.t @ 37631:2f626233859b
wireproto: implement batching on peer executor interface
This is a bit more complicated than non-batch requests because we
need to buffer sends until the last request arrives *and* we need
to support resolving futures as data arrives from the remote.
In a classical concurrent.futures executor model, the future
"starts" as soon as it is submitted. However, we have nothing to
start until the last command is submitted.
If we did nothing, calling result() would deadlock, since the future
hasn't "started." So in the case where we queue the command, we return
a special future type whose result() will trigger sendcommands().
This eliminates the deadlock potential. It also serves as a check
against callers who may be calling result() prematurely, as it will
prevent any subsequent callcommands() from working. This behavior
is slightly annoying and a bit restrictive. But it's the world
that half duplex connections forces on us.
In order to support streaming responses, we were previously using
a generator. But with a futures-based API, we're using futures
and not generators. So in order to get streaming, we need a
background thread to read data from the server.
The approach taken in this patch is to leverage the ThreadPoolExecutor
from concurrent.futures for managing a background thread. We create
an executor and future that resolves when all response data is
processed (or an error occurs). When exiting the context manager,
we wait on that background reading before returning.
I was hoping we could manually spin up a threading.Thread and this
would be simple. But I ran into a few deadlocks when implementing.
After looking at the source code to concurrent.futures, I figured
it would just be easier to use a ThreadPoolExecutor than implement
all the code needed to manually manage a thread.
To prove this works, a use of the batch API in discovery has been
updated.
Differential Revision: https://phab.mercurial-scm.org/D3269
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 13 Apr 2018 11:02:34 -0700 |
parents | bbf544b5f2e9 |
children |
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$ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH make a test repository that looks like this: o 2:28bc7b1afd6a | | @ 1:d7fe2034f71b |/ o 0/62ecad8b70e5 $ hg init r0 $ cd r0 $ touch f0 $ hg ci -m0 -Aq $ touch f1 $ hg ci -m1 -Aq $ hg update 0 -q $ touch f2 $ hg ci -m2 -Aq $ hg update 1 -q make some patches with a parent: 1:d7fe2034f71b -> p0 -> p1 $ echo cp0 >> fp0 $ hg add fp0 $ hg ci -m p0 -d "0 0" $ hg export -r. > p0 $ hg strip -qn . $ hg qimport p0 adding p0 to series file $ hg qpush applying p0 now at: p0 $ echo cp1 >> fp1 $ hg add fp1 $ hg qnew p1 -d "0 0" $ hg qpop -aq patch queue now empty qpush --exact when at the parent $ hg update 1 -q $ hg qpush -e applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg qpush -e p0 applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg qpush -e p1 applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty qpush --exact when at another rev $ hg update 0 -q $ hg qpush -e 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 0 -q $ hg qpush -e p0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 0 -q $ hg qpush -e p1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 0 -q $ hg qpush -ea 1 files updated, 0 files merged, 0 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty qpush --exact while crossing branches $ hg update 2 -q $ hg qpush -e 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 2 -q $ hg qpush -e p0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 now at: p0 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 2 -q $ hg qpush -e p1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty $ hg update 2 -q $ hg qpush -ea 1 files updated, 0 files merged, 1 files removed, 0 files unresolved applying p0 applying p1 now at: p1 $ hg parents -qr qbase 1:d7fe2034f71b $ hg qpop -aq patch queue now empty qpush --exact --force with changes to an unpatched file $ hg update 1 -q $ echo c0 >> f0 $ hg qpush -e abort: local changes found [255] $ hg qpush -ef applying p0 now at: p0 $ cat f0 c0 $ rm f0 $ touch f0 $ hg qpop -aq patch queue now empty $ hg update 1 -q $ echo c0 >> f0 $ hg qpush -e p1 abort: local changes found [255] $ hg qpush -e p1 -f applying p0 applying p1 now at: p1 $ cat f0 c0 $ rm f0 $ touch f0 $ hg qpop -aq patch queue now empty qpush --exact --force with changes to a patched file $ hg update 1 -q $ echo cp0-bad >> fp0 $ hg add fp0 $ hg qpush -e abort: local changes found [255] $ hg qpush -ef applying p0 file fp0 already exists 1 out of 1 hunks FAILED -- saving rejects to file fp0.rej patch failed, unable to continue (try -v) patch failed, rejects left in working directory errors during apply, please fix and qrefresh p0 [2] $ cat fp0 cp0-bad $ cat fp0.rej --- fp0 +++ fp0 @@ -0,0 +1,1 @@ +cp0 $ hg qpop -aqf patch queue now empty $ rm fp0 $ rm fp0.rej $ hg update 1 -q $ echo cp1-bad >> fp1 $ hg add fp1 $ hg qpush -e p1 abort: local changes found [255] $ hg qpush -e p1 -f applying p0 applying p1 file fp1 already exists 1 out of 1 hunks FAILED -- saving rejects to file fp1.rej patch failed, unable to continue (try -v) patch failed, rejects left in working directory errors during apply, please fix and qrefresh p1 [2] $ cat fp1 cp1-bad $ cat fp1.rej --- fp1 +++ fp1 @@ -0,0 +1,1 @@ +cp1 $ hg qpop -aqf patch queue now empty $ hg forget fp1 $ rm fp1 $ rm fp1.rej qpush --exact when already at a patch $ hg update 1 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg qpush -e p0 applying p0 now at: p0 $ hg qpush -e p1 abort: cannot push --exact with applied patches [255] $ hg qpop -aq patch queue now empty qpush --exact --move should fail $ hg qpush -e --move p1 abort: cannot use --exact and --move together [255] qpush --exact a patch without a parent recorded $ hg qpush -q now at: p0 $ grep -v '# Parent' .hg/patches/p0 > p0.new $ mv p0.new .hg/patches/p0 $ hg qpop -aq patch queue now empty $ hg qpush -e abort: p0 does not have a parent recorded [255] $ hg qpush -e p0 abort: p0 does not have a parent recorded [255] $ hg qpush -e p1 abort: p0 does not have a parent recorded [255] $ hg qpush -ea abort: p0 does not have a parent recorded [255] $ cd ..