Mercurial > hg
view tests/test-pull-pull-corruption.t @ 37048:fc5e261915b9
wireproto: require POST for all HTTPv2 requests
Wire protocol version 1 transfers argument data via request
headers by default. This has historically caused problems because
servers institute limits on the length of individual HTTP headers
as well as the total size of all request headers. Mercurial servers
can advertise the maximum length of an individual header. But
there's no guarantee any intermediate HTTP agents will accept
headers up to that length.
In the existing wire protocol, server operators typically also
key off the HTTP request method to implement authentication.
For example, GET requests translate to read-only requests and
can be allowed. But read-write commands must use POST and require
authentication. This has typically worked because the only wire
protocol commands that use POST modify the repo (e.g. the
"unbundle" command).
There is an experimental feature to enable clients to transmit
argument data via POST request bodies. This is technically a
better and more robust solution. But we can't enable it by default
because of servers assuming POST means write access.
In version 2 of the wire protocol, the permissions of a request
are encoded in the URL. And with it being a new protocol in a new
URL space, we're not constrained by backwards compatibility
requirements.
This commit adopts the technically superior mechanism of using
HTTP request bodies to send argument data by requiring POST for
all commands. Strictly speaking, it may be possible to send
request bodies on GET requests. But my experience is that not all
HTTP stacks support this. POST pretty much always works. Using POST
for read-only operations does sacrifice some RESTful design
purity. But this API cares about practicality, not about being
in Roy T. Fielding's REST ivory tower.
There's a chance we may relax this restriction in the future. But
for now, I want to see how far we can get with a POST only API.
Differential Revision: https://phab.mercurial-scm.org/D2837
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Tue, 13 Mar 2018 11:57:43 -0700 |
parents | eb586ed5d8ce |
children | f1186c292d03 |
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Corrupt an hg repo with two pulls. create one repo with a long history $ hg init source1 $ cd source1 $ touch foo $ hg add foo $ for i in 1 2 3 4 5 6 7 8 9 10; do > echo $i >> foo > hg ci -m $i > done $ cd .. create one repo with a shorter history $ hg clone -r 0 source1 source2 adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files new changesets 495a0ec48aaf updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd source2 $ echo a >> foo $ hg ci -m a $ cd .. create a third repo to pull both other repos into it $ hg init corrupted $ cd corrupted use a hook to make the second pull start while the first one is still running $ echo '[hooks]' >> .hg/hgrc $ echo 'prechangegroup = sleep 5' >> .hg/hgrc start a pull... $ hg pull ../source1 > pull.out 2>&1 & ... and start another pull before the first one has finished $ sleep 1 $ hg pull ../source2 2>/dev/null pulling from ../source2 searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) new changesets ca3c05af513e (run 'hg heads' to see heads, 'hg merge' to merge) $ cat pull.out pulling from ../source1 requesting all changes adding changesets adding manifests adding file changes added 10 changesets with 10 changes to 1 files new changesets 495a0ec48aaf:1e7b6c812ca8 (run 'hg update' to get a working copy) see the result $ wait $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 11 changesets, 11 total revisions $ cd ..