Mercurial > hg
view tests/test-show-work.t @ 36426:23d12524a202
http: drop custom http client logic
Eight and a half years ago, as my starter bug on code.google.com, I
investigated a mysterious "broken pipe" error from seemingly random
clients[0]. That investigation revealed a tragic story: the Python
standard library's httplib was (and remains) barely functional. During
large POSTs, if a server responds early with an error (even a
permission denied error!) the client only notices that the server
closed the connection and everything breaks. Such server behavior is
implicitly legal under RFC 2616 (the latest HTTP RFC as of when I was
last working on this), and my understanding is that later RFCs have
made it explicitly legal to respond early with any status code outside
the 2xx range.
I embarked, probably foolishly, on a journey to write a new http
library with better overall behavior. The http library appears to work
well in most cases, but it can get confused in the presence of
proxies, and it depends on select(2) which limits its utility if a lot
of file descriptors are open. I haven't touched the http library in
almost two years, and in the interim the Python community has
discovered a better way[1] of writing network code. In theory some day
urllib3 will have its own home-grown http library built on h11[2], or
we could do that. Either way, it's time to declare our current
confusingly-named "http2" client logic and move on. I do hope to
revisit this some day: it's still garbage that we can't even respond
with a 401 or 403 without reading the entire POST body from the
client, but the goalposts on writing a new http client library have
moved substantially. We're almost certainly better off just switching
to requests and eventually picking up their http fixes than trying to
live with something that realistically only we'll ever use. Another
approach would be to write an adapter so that Mercurial can use pycurl
if it's installed. Neither of those approaches seem like they should
be investigated prior to a release of Mercurial that works on Python
3: that's where the mindshare is going to be for any improvements to
the state of the http client art.
0: http://web.archive.org/web/20130501031801/http://code.google.com/p/support/issues/detail?id=2716
1: http://sans-io.readthedocs.io/
2: https://github.com/njsmith/h11
Differential Revision: https://phab.mercurial-scm.org/D2444
author | Augie Fackler <augie@google.com> |
---|---|
date | Sun, 25 Feb 2018 23:51:32 -0500 |
parents | 1a09dad8b85a |
children | 3c4b2e880273 |
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$ cat >> $HGRCPATH << EOF > [extensions] > show = > EOF $ hg init repo0 $ cd repo0 Command works on an empty repo $ hg show work Single draft changeset shown $ echo 0 > foo $ hg -q commit -A -m 'commit 0' $ hg show work @ 9f17 commit 0 Even when it isn't the wdir $ hg -q up null $ hg show work o 9f17 commit 0 Single changeset is still there when public because it is a head $ hg phase --public -r 0 $ hg show work o 9f17 commit 0 A draft child will show both it and public parent $ hg -q up 0 $ echo 1 > foo $ hg commit -m 'commit 1' $ hg show work @ 181c commit 1 o 9f17 commit 0 Multiple draft children will be shown $ echo 2 > foo $ hg commit -m 'commit 2' $ hg show work @ 128c commit 2 o 181c commit 1 o 9f17 commit 0 Bumping first draft changeset to public will hide its parent $ hg phase --public -r 1 $ hg show work @ 128c commit 2 o 181c commit 1 | ~ Multiple DAG heads will be shown $ hg -q up -r 1 $ echo 3 > foo $ hg commit -m 'commit 3' created new head $ hg show work @ f0ab commit 3 | o 128c commit 2 |/ o 181c commit 1 | ~ Even when wdir is something else $ hg -q up null $ hg show work o f0ab commit 3 | o 128c commit 2 |/ o 181c commit 1 | ~ Draft child shows public head (multiple heads) $ hg -q up 0 $ echo 4 > foo $ hg commit -m 'commit 4' created new head $ hg show work @ 668c commit 4 | o f0ab commit 3 | | o 128c commit 2 | |/ | o 181c commit 1 |/ o 9f17 commit 0 $ cd .. Branch name appears in output $ hg init branches $ cd branches $ echo 0 > foo $ hg -q commit -A -m 'commit 0' $ echo 1 > foo $ hg commit -m 'commit 1' $ echo 2 > foo $ hg commit -m 'commit 2' $ hg phase --public -r . $ hg -q up -r 1 $ hg branch mybranch marked working directory as branch mybranch (branches are permanent and global, did you want a bookmark?) $ echo 3 > foo $ hg commit -m 'commit 3' $ echo 4 > foo $ hg commit -m 'commit 4' $ hg show work @ f8dd (mybranch) commit 4 o 90cf (mybranch) commit 3 | o 128c commit 2 |/ o 181c commit 1 | ~ $ cd .. Bookmark name appears in output $ hg init bookmarks $ cd bookmarks $ echo 0 > foo $ hg -q commit -A -m 'commit 0' $ echo 1 > foo $ hg commit -m 'commit 1' $ echo 2 > foo $ hg commit -m 'commit 2' $ hg phase --public -r . $ hg bookmark @ $ hg -q up -r 1 $ echo 3 > foo $ hg commit -m 'commit 3' created new head $ echo 4 > foo $ hg commit -m 'commit 4' $ hg bookmark mybook $ hg show work @ cac8 (mybook) commit 4 o f0ab commit 3 | o 128c (@) commit 2 |/ o 181c commit 1 | ~ $ cd .. Tags are rendered $ hg init tags $ cd tags $ echo 0 > foo $ hg -q commit -A -m 'commit 1' $ echo 1 > foo $ hg commit -m 'commit 2' $ hg tag 0.1 $ hg phase --public -r . $ echo 2 > foo $ hg commit -m 'commit 3' $ hg tag 0.2 $ hg show work @ 3758 Added tag 0.2 for changeset 6379c25b76f1 o 6379 (0.2) commit 3 o a2ad Added tag 0.1 for changeset 6a75536ea0b1 | ~ $ cd .. Multiple names on same changeset render properly $ hg init multiplenames $ cd multiplenames $ echo 0 > foo $ hg -q commit -A -m 'commit 1' $ hg phase --public -r . $ hg branch mybranch marked working directory as branch mybranch (branches are permanent and global, did you want a bookmark?) $ hg bookmark mybook $ echo 1 > foo $ hg commit -m 'commit 2' $ hg show work @ 3483 (mybook) (mybranch) commit 2 o 97fc commit 1 Multiple bookmarks on same changeset render properly $ hg book mybook2 $ hg show work @ 3483 (mybook mybook2) (mybranch) commit 2 o 97fc commit 1 $ cd .. Extra namespaces are rendered $ hg init extranamespaces $ cd extranamespaces $ echo 0 > foo $ hg -q commit -A -m 'commit 1' $ hg phase --public -r . $ echo 1 > foo $ hg commit -m 'commit 2' $ echo 2 > foo $ hg commit -m 'commit 3' $ hg --config extensions.revnames=$TESTDIR/revnamesext.py show work @ 32f3 (r2) commit 3 o 6a75 (r1) commit 2 o 97fc (r0) commit 1 Obsolescence information appears in labels. $ cat >> .hg/hgrc << EOF > [experimental] > evolution=createmarkers > EOF $ hg debugobsolete `hg log -r 'desc("commit 2")' -T "{node}"` obsoleted 1 changesets 1 new orphan changesets $ hg show work --color=debug @ [log.changeset changeset.draft changeset.unstable instability.orphan|32f3] [log.description|commit 3] x [log.changeset changeset.draft changeset.obsolete|6a75] [log.description|commit 2] | ~ $ cd .. Prefix collision on hashes increases shortest node length $ hg init hashcollision $ cd hashcollision $ echo 0 > a $ hg -q commit -Am 0 $ for i in 17 1057 2857 4025; do > hg -q up 0 > echo $i > a > hg -q commit -m $i > echo 0 > a > hg commit -m "$i commit 2" > done $ hg show work @ cfd04 4025 commit 2 o c562d 4025 | o 08048 2857 commit 2 | o c5623 2857 |/ | o 6a6b6 1057 commit 2 | o c5625 1057 |/ | o 96b4e 17 commit 2 | o 11424 17 |/ o b4e73 0 $ cd ..