Mercurial > hg
view tests/test-excessive-merge.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
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 29 Aug 2018 15:17:11 -0700 |
parents | f1186c292d03 |
children | ccd76e292be5 |
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$ hg init $ echo foo > a $ echo foo > b $ hg add a b $ hg ci -m "test" $ echo blah > a $ hg ci -m "branch a" $ hg co 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo blah > b $ hg ci -m "branch b" created new head $ HGMERGE=true hg merge 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m "merge b/a -> blah" $ hg co 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ HGMERGE=true hg merge 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m "merge a/b -> blah" created new head $ hg log changeset: 4:2ee31f665a86 tag: tip parent: 1:96155394af80 parent: 2:92cc4c306b19 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: merge a/b -> blah changeset: 3:e16a66a37edd parent: 2:92cc4c306b19 parent: 1:96155394af80 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: merge b/a -> blah changeset: 2:92cc4c306b19 parent: 0:5e0375449e74 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: branch b changeset: 1:96155394af80 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: branch a changeset: 0:5e0375449e74 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: test $ hg debugindex --changelog rev linkrev nodeid p1 p2 0 0 5e0375449e74 000000000000 000000000000 1 1 96155394af80 5e0375449e74 000000000000 2 2 92cc4c306b19 5e0375449e74 000000000000 3 3 e16a66a37edd 92cc4c306b19 96155394af80 4 4 2ee31f665a86 96155394af80 92cc4c306b19 revision 1 $ hg manifest --debug 1 79d7492df40aa0fa093ec4209be78043c181f094 644 a 2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 b revision 2 $ hg manifest --debug 2 2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 a 79d7492df40aa0fa093ec4209be78043c181f094 644 b revision 3 $ hg manifest --debug 3 79d7492df40aa0fa093ec4209be78043c181f094 644 a 79d7492df40aa0fa093ec4209be78043c181f094 644 b revision 4 $ hg manifest --debug 4 79d7492df40aa0fa093ec4209be78043c181f094 644 a 79d7492df40aa0fa093ec4209be78043c181f094 644 b $ hg debugindex a rev linkrev nodeid p1 p2 0 0 2ed2a3912a0b 000000000000 000000000000 1 1 79d7492df40a 2ed2a3912a0b 000000000000 $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 5 changesets with 4 changes to 2 files