view tests/test-setdiscovery.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

Function to test discovery between two repos in both directions, using both the local shortcut
(which is currently not activated by default) and the full remotable protocol:

  $ testdesc() { # revs_a, revs_b, dagdesc
  >     if [ -d foo ]; then rm -rf foo; fi
  >     hg init foo
  >     cd foo
  >     hg debugbuilddag "$3"
  >     hg clone . a $1 --quiet
  >     hg clone . b $2 --quiet
  >     echo
  >     echo "% -- a -> b tree"
  >     hg -R a debugdiscovery b --verbose --old
  >     echo
  >     echo "% -- a -> b set"
  >     hg -R a debugdiscovery b --verbose --debug --config progress.debug=true
  >     echo
  >     echo "% -- a -> b set (tip only)"
  >     hg -R a debugdiscovery b --verbose --debug --config progress.debug=true --rev tip
  >     echo
  >     echo "% -- b -> a tree"
  >     hg -R b debugdiscovery a --verbose --old
  >     echo
  >     echo "% -- b -> a set"
  >     hg -R b debugdiscovery a --verbose --debug --config progress.debug=true
  >     echo
  >     echo "% -- b -> a set (tip only)"
  >     hg -R b debugdiscovery a --verbose --debug --config progress.debug=true --rev tip
  >     cd ..
  > }


Small superset:

  $ testdesc '-ra1 -ra2' '-rb1 -rb2 -rb3' '
  > +2:f +1:a1:b1
  > <f +4 :a2
  > +5 :b2
  > <f +3 :b3'
  
  % -- a -> b tree
  comparing with b
  searching for changes
  unpruned common: 01241442b3c2 66f7d451a68b b5714e113bc0
  common heads: 01241442b3c2 b5714e113bc0
  local is subset
  
  % -- a -> b set
  comparing with b
  query 1; heads
  searching for changes
  all local heads known remotely
  common heads: 01241442b3c2 b5714e113bc0
  local is subset
  
  % -- a -> b set (tip only)
  comparing with b
  query 1; heads
  searching for changes
  all local heads known remotely
  common heads: b5714e113bc0
  
  % -- b -> a tree
  comparing with a
  searching for changes
  unpruned common: 01241442b3c2 b5714e113bc0
  common heads: 01241442b3c2 b5714e113bc0
  remote is subset
  
  % -- b -> a set
  comparing with a
  query 1; heads
  searching for changes
  all remote heads known locally
  common heads: 01241442b3c2 b5714e113bc0
  remote is subset
  
  % -- b -> a set (tip only)
  comparing with a
  query 1; heads
  searching for changes
  all remote heads known locally
  common heads: 01241442b3c2 b5714e113bc0
  remote is subset


Many new:

  $ testdesc '-ra1 -ra2' '-rb' '
  > +2:f +3:a1 +3:b
  > <f +30 :a2'
  
  % -- a -> b tree
  comparing with b
  searching for changes
  unpruned common: bebd167eb94d
  common heads: bebd167eb94d
  
  % -- a -> b set
  comparing with b
  query 1; heads
  searching for changes
  taking initial sample
  searching: 2 queries
  query 2; still undecided: 29, sample size is: 29
  2 total queries in *.????s (glob)
  common heads: bebd167eb94d
  
  % -- a -> b set (tip only)
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- b -> a tree
  comparing with a
  searching for changes
  unpruned common: 66f7d451a68b bebd167eb94d
  common heads: bebd167eb94d
  
  % -- b -> a set
  comparing with a
  query 1; heads
  searching for changes
  taking initial sample
  searching: 2 queries
  query 2; still undecided: 2, sample size is: 2
  2 total queries in *.????s (glob)
  common heads: bebd167eb94d
  
  % -- b -> a set (tip only)
  comparing with a
  query 1; heads
  searching for changes
  taking initial sample
  searching: 2 queries
  query 2; still undecided: 2, sample size is: 2
  2 total queries in *.????s (glob)
  common heads: bebd167eb94d

Both sides many new with stub:

  $ testdesc '-ra1 -ra2' '-rb' '
  > +2:f +2:a1 +30 :b
  > <f +30 :a2'
  
  % -- a -> b tree
  comparing with b
  searching for changes
  unpruned common: 2dc09a01254d
  common heads: 2dc09a01254d
  
  % -- a -> b set
  comparing with b
  query 1; heads
  searching for changes
  taking initial sample
  searching: 2 queries
  query 2; still undecided: 29, sample size is: 29
  2 total queries in *.????s (glob)
  common heads: 2dc09a01254d
  
  % -- a -> b set (tip only)
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- b -> a tree
  comparing with a
  searching for changes
  unpruned common: 2dc09a01254d 66f7d451a68b
  common heads: 2dc09a01254d
  
  % -- b -> a set
  comparing with a
  query 1; heads
  searching for changes
  taking initial sample
  searching: 2 queries
  query 2; still undecided: 29, sample size is: 29
  2 total queries in *.????s (glob)
  common heads: 2dc09a01254d
  
  % -- b -> a set (tip only)
  comparing with a
  query 1; heads
  searching for changes
  taking initial sample
  searching: 2 queries
  query 2; still undecided: 29, sample size is: 29
  2 total queries in *.????s (glob)
  common heads: 2dc09a01254d


Both many new:

  $ testdesc '-ra' '-rb' '
  > +2:f +30 :b
  > <f +30 :a'
  
  % -- a -> b tree
  comparing with b
  searching for changes
  unpruned common: 66f7d451a68b
  common heads: 66f7d451a68b
  
  % -- a -> b set
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- a -> b set (tip only)
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- b -> a tree
  comparing with a
  searching for changes
  unpruned common: 66f7d451a68b
  common heads: 66f7d451a68b
  
  % -- b -> a set
  comparing with a
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- b -> a set (tip only)
  comparing with a
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b


Both many new skewed:

  $ testdesc '-ra' '-rb' '
  > +2:f +30 :b
  > <f +50 :a'
  
  % -- a -> b tree
  comparing with b
  searching for changes
  unpruned common: 66f7d451a68b
  common heads: 66f7d451a68b
  
  % -- a -> b set
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 51, sample size is: 51
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- a -> b set (tip only)
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 51, sample size is: 51
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- b -> a tree
  comparing with a
  searching for changes
  unpruned common: 66f7d451a68b
  common heads: 66f7d451a68b
  
  % -- b -> a set
  comparing with a
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b
  
  % -- b -> a set (tip only)
  comparing with a
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 31, sample size is: 31
  2 total queries in *.????s (glob)
  common heads: 66f7d451a68b


Both many new on top of long history:

  $ testdesc '-ra' '-rb' '
  > +1000:f +30 :b
  > <f +50 :a'
  
  % -- a -> b tree
  comparing with b
  searching for changes
  unpruned common: 7ead0cba2838
  common heads: 7ead0cba2838
  
  % -- a -> b set
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 1049, sample size is: 11
  sampling from both directions
  searching: 3 queries
  query 3; still undecided: 31, sample size is: 31
  3 total queries in *.????s (glob)
  common heads: 7ead0cba2838
  
  % -- a -> b set (tip only)
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 1049, sample size is: 11
  sampling from both directions
  searching: 3 queries
  query 3; still undecided: 31, sample size is: 31
  3 total queries in *.????s (glob)
  common heads: 7ead0cba2838
  
  % -- b -> a tree
  comparing with a
  searching for changes
  unpruned common: 7ead0cba2838
  common heads: 7ead0cba2838
  
  % -- b -> a set
  comparing with a
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 1029, sample size is: 11
  sampling from both directions
  searching: 3 queries
  query 3; still undecided: 15, sample size is: 15
  3 total queries in *.????s (glob)
  common heads: 7ead0cba2838
  
  % -- b -> a set (tip only)
  comparing with a
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 1029, sample size is: 11
  sampling from both directions
  searching: 3 queries
  query 3; still undecided: 15, sample size is: 15
  3 total queries in *.????s (glob)
  common heads: 7ead0cba2838


One with >200 heads, which used to use up all of the sample:

  $ hg init manyheads
  $ cd manyheads
  $ echo "+300:r @a" >dagdesc
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3 *r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3*r+3" >>dagdesc # 20 heads
  $ echo "@b *r+3" >>dagdesc # one more head
  $ hg debugbuilddag <dagdesc
  reading DAG from stdin

  $ hg heads -t --template . | wc -c
  \s*261 (re)

  $ hg clone -b a . a
  adding changesets
  adding manifests
  adding file changes
  added 1340 changesets with 0 changes to 0 files (+259 heads)
  new changesets 1ea73414a91b:1c51e2c80832
  updating to branch a
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg clone -b b . b
  adding changesets
  adding manifests
  adding file changes
  added 304 changesets with 0 changes to 0 files
  new changesets 1ea73414a91b:513314ca8b3a
  updating to branch b
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R a debugdiscovery b --debug --verbose --config progress.debug=true
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 1240, sample size is: 100
  sampling from both directions
  searching: 3 queries
  query 3; still undecided: 1140, sample size is: 200
  sampling from both directions
  searching: 4 queries
  query 4; still undecided: \d+, sample size is: 200 (re)
  sampling from both directions
  searching: 5 queries
  query 5; still undecided: \d+, sample size is: 200 (re)
  sampling from both directions
  searching: 6 queries
  query 6; still undecided: \d+, sample size is: \d+ (re)
  6 total queries in *.????s (glob)
  common heads: 3ee37d65064a
  $ hg -R a debugdiscovery b --debug --verbose --config progress.debug=true --rev tip
  comparing with b
  query 1; heads
  searching for changes
  taking quick initial sample
  searching: 2 queries
  query 2; still undecided: 303, sample size is: 9
  sampling from both directions
  searching: 3 queries
  query 3; still undecided: 3, sample size is: 3
  3 total queries in *.????s (glob)
  common heads: 3ee37d65064a

Test actual protocol when pulling one new head in addition to common heads

  $ hg clone -U b c
  $ hg -R c id -ir tip
  513314ca8b3a
  $ hg -R c up -qr default
  $ touch c/f
  $ hg -R c ci -Aqm "extra head"
  $ hg -R c id -i
  e64a39e7da8b

  $ hg serve -R c -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
  $ cat hg.pid >> $DAEMON_PIDS

  $ hg -R b incoming http://localhost:$HGPORT/ -T '{node|short}\n'
  comparing with http://localhost:$HGPORT/
  searching for changes
  e64a39e7da8b

  $ killdaemons.py
  $ cut -d' ' -f6- access.log | grep -v cmd=known # cmd=known uses random sampling
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=batch HTTP/1.1" 200 - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D513314ca8b3ae4dac8eec56966265b00fcf866db x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$
  "GET /?cmd=getbundle HTTP/1.1" 200 - x-hgarg-1:$USUAL_BUNDLE_CAPS$&cg=1&common=513314ca8b3ae4dac8eec56966265b00fcf866db&heads=e64a39e7da8b0d54bc63e81169aff001c13b3477 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$
  $ cat errors.log

  $ cd ..


Issue 4438 - test coverage for 3ef893520a85 issues.

  $ mkdir issue4438
  $ cd issue4438
#if false
generate new bundles:
  $ hg init r1
  $ for i in `$PYTHON $TESTDIR/seq.py 101`; do hg -R r1 up -qr null && hg -R r1 branch -q b$i && hg -R r1 ci -qmb$i; done
  $ hg clone -q r1 r2
  $ for i in `$PYTHON $TESTDIR/seq.py 10`; do hg -R r1 up -qr null && hg -R r1 branch -q c$i && hg -R r1 ci -qmc$i; done
  $ hg -R r2 branch -q r2change && hg -R r2 ci -qmr2change
  $ hg -R r1 bundle -qa $TESTDIR/bundles/issue4438-r1.hg
  $ hg -R r2 bundle -qa $TESTDIR/bundles/issue4438-r2.hg
#else
use existing bundles:
  $ hg clone -q $TESTDIR/bundles/issue4438-r1.hg r1
  $ hg clone -q $TESTDIR/bundles/issue4438-r2.hg r2
#endif

Set iteration order could cause wrong and unstable results - fixed in 73cfaa348650:

  $ hg -R r1 outgoing r2 -T'{rev} '
  comparing with r2
  searching for changes
  101 102 103 104 105 106 107 108 109 110  (no-eol)

The case where all the 'initialsamplesize' samples already were common would
give 'all remote heads known locally' without checking the remaining heads -
fixed in 86c35b7ae300:

  $ cat >> $TESTTMP/unrandomsample.py << EOF
  > import random
  > def sample(population, k):
  >     return sorted(population)[:k]
  > random.sample = sample
  > EOF

  $ cat >> r1/.hg/hgrc << EOF
  > [extensions]
  > unrandomsample = $TESTTMP/unrandomsample.py
  > EOF

  $ hg -R r1 outgoing r2 -T'{rev} ' --config extensions.blackbox=
  comparing with r2
  searching for changes
  101 102 103 104 105 106 107 108 109 110  (no-eol)
  $ hg -R r1 --config extensions.blackbox= blackbox
  * @5d0b986a083e0d91f116de4691e2aaa54d5bbec0 (*)> serve --cmdserver chgunix * (glob) (chg !)
  * @5d0b986a083e0d91f116de4691e2aaa54d5bbec0 (*)> -R r1 outgoing r2 *-T{rev} * --config *extensions.blackbox=* (glob)
  * @5d0b986a083e0d91f116de4691e2aaa54d5bbec0 (*)> found 101 common and 1 unknown server heads, 2 roundtrips in *.????s (glob)
  * @5d0b986a083e0d91f116de4691e2aaa54d5bbec0 (*)> -R r1 outgoing r2 *-T{rev} * --config *extensions.blackbox=* exited 0 after *.?? seconds (glob)
  * @5d0b986a083e0d91f116de4691e2aaa54d5bbec0 (*)> -R r1 --config *extensions.blackbox=* blackbox (glob)
  $ cd ..