hgweb: refactor the request draining code
The previous code for draining was only invoked in a few places in
the wire protocol. Behavior wasn't consist. Furthermore, it was
difficult to reason about.
With us converting the input stream to a capped reader, it is now
safe to always drain the input stream when its size is known because
we can never overrun the input and read into the next HTTP request.
The only question is "should we?"
This commit changes the draining code so every request is examined.
Draining now kicks in for a few requests where it wouldn't before.
But I think the code is sufficiently restricted so the behavior is
safe. Possibly the most dangerous part of this code is the issuing
of Connection: close for POST and PUT requests that don't have a
Content-Length. I don't think there are any such uses in our WSGI
application, so this should be safe.
In the near future, I plan to significantly refactor the WSGI
response handling. I anticipate this code evolving a bit. So any
minor regressions around draining or connection closing behavior
might be fixed as a result of that work.
All tests pass with this change. That scares me a bit because it
means we are lacking low-level tests for the HTTP protocol.
Differential Revision: https://phab.mercurial-scm.org/D2769
#require cvs112
This feature requires use of builtin cvsps!
$ echo "[extensions]" >> $HGRCPATH
$ echo "convert = " >> $HGRCPATH
create cvs repository with one project
$ mkdir cvsrepo
$ cd cvsrepo
$ CVSROOT=`pwd`
$ export CVSROOT
$ CVS_OPTIONS=-f
$ export CVS_OPTIONS
$ cd ..
$ rmdir cvsrepo
$ cvscall()
> {
> cvs -f "$@"
> }
output of 'cvs ci' varies unpredictably, so just discard it
$ cvsci()
> {
> sleep 1
> cvs -f ci "$@" >/dev/null
> }
$ cvscall -d "$CVSROOT" init
$ mkdir cvsrepo/proj
$ cvscall -q co proj
create file1 on the trunk
$ cd proj
$ touch file1
$ cvscall -Q add file1
$ cvsci -m"add file1 on trunk" file1
create two branches
$ cvscall -q tag -b v1_0
T file1
$ cvscall -q tag -b v1_1
T file1
create file2 on branch v1_0
$ cvscall -Q up -rv1_0
$ touch file2
$ cvscall -Q add file2
$ cvsci -m"add file2" file2
create file3, file4 on branch v1_1
$ cvscall -Q up -rv1_1
$ touch file3
$ touch file4
$ cvscall -Q add file3 file4
$ cvsci -m"add file3, file4 on branch v1_1" file3 file4
merge file2 from v1_0 to v1_1
$ cvscall -Q up -jv1_0
$ cvsci -m"MERGE from v1_0: add file2"
cvs commit: Examining .
Step things up a notch: now we make the history really hairy, with
changes bouncing back and forth between trunk and v1_2 and merges
going both ways. (I.e., try to model the real world.)
create branch v1_2
$ cvscall -Q up -A
$ cvscall -q tag -b v1_2
T file1
create file5 on branch v1_2
$ cvscall -Q up -rv1_2
$ touch file5
$ cvs -Q add file5
$ cvsci -m"add file5 on v1_2"
cvs commit: Examining .
create file6 on trunk post-v1_2
$ cvscall -Q up -A
$ touch file6
$ cvscall -Q add file6
$ cvsci -m"add file6 on trunk post-v1_2"
cvs commit: Examining .
merge file5 from v1_2 to trunk
$ cvscall -Q up -A
$ cvscall -Q up -jv1_2 file5
$ cvsci -m"MERGE from v1_2: add file5"
cvs commit: Examining .
merge file6 from trunk to v1_2
$ cvscall -Q up -rv1_2
$ cvscall up -jHEAD file6
U file6
$ cvsci -m"MERGE from HEAD: add file6"
cvs commit: Examining .
cvs rlog output
$ cvscall -q rlog proj | egrep '^(RCS file|revision)'
RCS file: $TESTTMP/cvsrepo/proj/file1,v
revision 1.1
RCS file: $TESTTMP/cvsrepo/proj/Attic/file2,v
revision 1.1
revision 1.1.4.2
revision 1.1.4.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/Attic/file3,v
revision 1.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/Attic/file4,v
revision 1.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/file5,v
revision 1.2
revision 1.1
revision 1.1.2.1
RCS file: $TESTTMP/cvsrepo/proj/file6,v
revision 1.1
revision 1.1.2.2
revision 1.1.2.1
convert to hg (#1)
$ cd ..
$ hg convert --datesort proj proj.hg
initializing destination proj.hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
15 log entries
creating changesets
9 changeset entries
sorting...
converting...
8 add file1 on trunk
7 add file2
6 MERGE from v1_0: add file2
5 file file3 was initially added on branch v1_1.
4 add file3, file4 on branch v1_1
3 add file5 on v1_2
2 add file6 on trunk post-v1_2
1 MERGE from HEAD: add file6
0 MERGE from v1_2: add file5
hg log -G output (#1)
$ hg -R proj.hg log -G --template "{rev} {desc}\n"
o 8 MERGE from v1_2: add file5
|
| o 7 MERGE from HEAD: add file6
| |
o | 6 add file6 on trunk post-v1_2
| |
| o 5 add file5 on v1_2
| |
| | o 4 add file3, file4 on branch v1_1
| | |
o | | 3 file file3 was initially added on branch v1_1.
|/ /
| o 2 MERGE from v1_0: add file2
|/
| o 1 add file2
|/
o 0 add file1 on trunk
convert to hg (#2: with merge detection)
$ hg convert \
> --config convert.cvsps.mergefrom='"^MERGE from (\S+):"' \
> --datesort \
> proj proj.hg2
initializing destination proj.hg2 repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
15 log entries
creating changesets
9 changeset entries
sorting...
converting...
8 add file1 on trunk
7 add file2
6 MERGE from v1_0: add file2
5 file file3 was initially added on branch v1_1.
4 add file3, file4 on branch v1_1
3 add file5 on v1_2
2 add file6 on trunk post-v1_2
1 MERGE from HEAD: add file6
0 MERGE from v1_2: add file5
hg log -G output (#2)
$ hg -R proj.hg2 log -G --template "{rev} {desc}\n"
o 8 MERGE from v1_2: add file5
|
| o 7 MERGE from HEAD: add file6
| |
o | 6 add file6 on trunk post-v1_2
| |
| o 5 add file5 on v1_2
| |
| | o 4 add file3, file4 on branch v1_1
| | |
o | | 3 file file3 was initially added on branch v1_1.
|/ /
| o 2 MERGE from v1_0: add file2
|/
| o 1 add file2
|/
o 0 add file1 on trunk