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view tests/test-branch-option.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 | eb586ed5d8ce |
children | 95c4cca641f6 |
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test branch selection options $ hg init branch $ cd branch $ hg branch a marked working directory as branch a (branches are permanent and global, did you want a bookmark?) $ echo a > foo $ hg ci -d '0 0' -Ama adding foo $ echo a2 > foo $ hg ci -d '0 0' -ma2 $ hg up 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg branch c marked working directory as branch c $ echo c > foo $ hg ci -d '0 0' -mc $ hg tag -l z $ cd .. $ hg clone -r 0 branch branch2 adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files new changesets 5b65ba7c951d updating to branch a 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd branch2 $ hg up 0 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg branch b marked working directory as branch b $ echo b > foo $ hg ci -d '0 0' -mb $ hg up 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg --encoding utf-8 branch æ marked working directory as branch \xc3\xa6 (esc) $ echo ae1 > foo $ hg ci -d '0 0' -mae1 $ hg up 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg --encoding utf-8 branch -f æ marked working directory as branch \xc3\xa6 (esc) $ echo ae2 > foo $ hg ci -d '0 0' -mae2 created new head $ hg up 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg branch -f b marked working directory as branch b $ echo b2 > foo $ hg ci -d '0 0' -mb2 created new head unknown branch and fallback $ hg in -qbz abort: unknown branch 'z'! [255] $ hg in -q ../branch#z 2:f25d57ab0566 $ hg out -qbz abort: unknown branch 'z'! [255] in rev c branch a $ hg in -qr c ../branch#a 1:dd6e60a716c6 2:f25d57ab0566 $ hg in -qr c -b a 1:dd6e60a716c6 2:f25d57ab0566 out branch . $ hg out -q ../branch#. 1:b84708d77ab7 4:65511d0e2b55 $ hg out -q -b . 1:b84708d77ab7 4:65511d0e2b55 out branch . non-ascii $ hg --encoding utf-8 up æ 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg --encoding latin1 out -q ../branch#. 2:df5a44224d4e 3:4f4a5125ca10 $ hg --encoding latin1 out -q -b . 2:df5a44224d4e 3:4f4a5125ca10 clone branch b $ cd .. $ hg clone branch2#b branch3 adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files (+1 heads) new changesets 5b65ba7c951d:65511d0e2b55 updating to branch b 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg -q -R branch3 heads b 2:65511d0e2b55 1:b84708d77ab7 $ hg -q -R branch3 parents 2:65511d0e2b55 $ rm -rf branch3 clone rev a branch b $ hg clone -r a branch2#b branch3 adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files (+1 heads) new changesets 5b65ba7c951d:65511d0e2b55 updating to branch a 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg -q -R branch3 heads b 2:65511d0e2b55 1:b84708d77ab7 $ hg -q -R branch3 parents 0:5b65ba7c951d $ rm -rf branch3