Mercurial > hg
view tests/test-push-checkheads-pruned-B2.t @ 37711:65a23cc8e75b
cborutil: implement support for streaming encoding, bytestring decoding
The vendored cbor2 package is... a bit disappointing.
On the encoding side, it insists that you pass it something with
a write() to send data to. That means if you want to emit data to
a generator, you have to construct an e.g. io.BytesIO(), write()
to it, then get the data back out. There can be non-trivial overhead
involved.
The encoder also doesn't support indefinite types - bytestrings, arrays,
and maps that don't have a known length. Again, this is really
unfortunate because it requires you to buffer the entire source and
destination in memory to encode large things.
On the decoding side, it supports reading indefinite length types.
But it buffers them completely before returning. More sadness.
This commit implements "streaming" encoders for various CBOR types.
Encoding emits a generator of hunks. So you can efficiently stream
encoded data elsewhere.
It also implements support for emitting indefinite length bytestrings,
arrays, and maps.
On the decoding side, we only implement support for decoding an
indefinite length bytestring from a file object. It will emit a
generator of raw chunks from the source.
I didn't want to reinvent so many wheels. But profiling the wire
protocol revealed that the overhead of constructing io.BytesIO()
instances to temporarily hold results has a non-trivial overhead.
We're talking >15% of execution time for operations like
"transfer the fulltexts of all files in a revision." So I can
justify this effort.
Fortunately, CBOR is a relatively straightforward format. And we have
a reference implementation in the repo we can test against.
Differential Revision: https://phab.mercurial-scm.org/D3303
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 14 Apr 2018 16:36:15 -0700 |
parents | 1a09dad8b85a |
children | 89630d0b3e23 |
line wrap: on
line source
==================================== Testing head checking code: Case B-2 ==================================== Mercurial checks for the introduction of new heads on push. Evolution comes into play to detect if existing branches on the server are being replaced by some of the new one we push. This case is part of a series of tests checking this behavior. Category B: simple case involving pruned changesets TestCase 2: multi-changeset branch, head is pruned, rest is superceeded .. old-state: .. .. * 2 changeset branch .. .. new-state: .. .. * old head is pruned .. * 1 new branch succeeding to the other changeset in the old branch .. .. expected-result: .. .. * push allowed .. .. graph-summary: .. .. B ⊗ .. | .. A ø⇠◔ A' .. |/ .. ● $ . $TESTDIR/testlib/push-checkheads-util.sh Test setup ---------- $ mkdir B2 $ cd B2 $ setuprepos creating basic server and client repo updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd server $ mkcommit B0 $ cd ../client $ hg pull pulling from $TESTTMP/B2/server searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files new changesets d73caddc5533 (run 'hg update' to get a working copy) $ hg up 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ mkcommit A1 created new head $ hg debugobsolete `getid "desc(A0)" ` `getid "desc(A1)"` obsoleted 1 changesets 1 new orphan changesets $ hg debugobsolete --record-parents `getid "desc(B0)"` obsoleted 1 changesets $ hg log -G --hidden @ f6082bc4ffef (draft): A1 | | x d73caddc5533 (draft): B0 | | | x 8aaa48160adc (draft): A0 |/ o 1e4be0697311 (public): root Actual testing -------------- $ hg push pushing to $TESTTMP/B2/server searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) 2 new obsolescence markers obsoleted 2 changesets $ cd ../..