tests/testlib/exchange-obsmarker-util.sh

wireproto: implement basic frame reading and processing

We just implemented support for writing frames. Now let's implement
support for reading them.

The bulk of the new code is for a class that maintains the state of
a server. Essentially, you construct an instance, feed frames to it,
and it tells you what you should do next. The design is inspired by
the "sans I/O" movement and the reactor pattern. We don't want to
perform I/O or any major blocking event during frame ingestion because
this arbitrarily limits ways that server pieces can be implemented.
For example, it makes it much harder to swap in an alternate
implementation based on asyncio or do crazy things like have requests
dispatch to other processes.

We do still implement readframe() which does I/O. But it is decoupled
from the server reactor. And important parsing of frame headers is
a standalone function. So I/O is only needed to obtain frame data.

Because testing server-side ingest is useful and difficult on running
servers, we create a new "debugreflect" endpoint that will echo back
to the client what was received and how it was interpreted. This could
be useful for a server admin, someone implementing a client. But
immediately, it is useful for testing: we're able to demonstrate that
frames are parsed correctly and turned into requests to run commands
without having to implement command dispatch on the server!

In addition, we implement Python level unit tests for the reactor.
This is vastly more efficient than sending requests to the
"debugreflect" endpoint and vastly more powerful for advanced
testing.

Differential Revision: https://phab.mercurial-scm.org/D2852

#!/bin/sh
# setup config and various utility to test obsolescence marker exchanges tests

cat >> $TESTTMP/prune.sh << EOF
rev=\`hg log --hidden --template '{node}\n' --rev "\$3"\`

hg debugobsolete --record-parents \$1 "\$2" \$rev \
   && hg up --quiet 'max((::.) - obsolete())'
EOF

cat >> $HGRCPATH <<EOF
[web]
# We test http pull and push, drop authentication requirement
push_ssl = false
allow_push = *

[ui]
# simpler log output
logtemplate ="{node|short} ({phase}): {desc}\n"

[phases]
# non publishing server
publish=False

[experimental]
# reduce output changes
bundle2-output-capture=True
# enable evolution
evolution=true

[extensions]
# we need to strip some changeset for some test cases
hgext.strip=

[devel]
strip-obsmarkers = no

[alias]
# fix date used to create obsolete markers.
debugobsolete=debugobsolete -d '0 0'
# poor man substiture to the evolve 'hg prune'. using prune makes the test clearer and 
prune = !sh $TESTTMP/prune.sh \$1 "\$2" "\$3"
EOF

mkcommit() {
   echo "$1" > "$1"
   hg add "$1"
   hg ci -m "$1"
}
getid() {
   hg log --hidden --template '{node}\n' --rev "$1"
}

setuprepos() {
    echo creating test repo for test case $1
    mkdir $1
    cd $1
    echo - pulldest
    hg init pushdest
    cd pushdest
    mkcommit O
    hg phase --public .
    cd ..
    echo - main
    hg clone -q pushdest main
    echo - pushdest
    hg clone -q main pulldest
    echo 'cd into `main` and proceed with env setup'
}

inspect_obsmarkers (){
    # This exist as its own function to help the evolve extension reuse the tests as is.
    # The evolve extensions version will includes more advances query (eg:
    # related to obsmarkers discovery) to this.
    echo 'obsstore content'
    echo '================'
    hg debugobsolete
}

dotest() {
    # dotest TESTNAME [TARGETNODE] [PUSHFLAGS+]
    #
    # test exchange for the given test case.
    #
    # This function performs push and pull in all directions through all
    # protocols and display the resulting obsolescence markers on all sides.

    testcase=$1
    shift
    target="$1"
    if [ $# -gt 0 ]; then
        shift
    fi
    targetnode=""
    desccall=""
    cd $testcase
    echo "## Running testcase $testcase"
    if [ -n "$target" ]; then
        desccall="desc("\'"$target"\'")"
        targetnode="`hg -R main id -qr \"$desccall\"`"
        echo "# testing echange of \"$target\" ($targetnode)"
    fi
    echo "## initial state"
    echo "# obstore: main"
    hg -R main     debugobsolete | sort
    echo "# obstore: pushdest"
    hg -R pushdest debugobsolete | sort
    echo "# obstore: pulldest"
    hg -R pulldest debugobsolete | sort

    if [ -n "$target" ]; then
        echo "## pushing \"$target\"" from main to pushdest
        hg -R main push -r "$desccall" $@ pushdest
    else
        echo "## pushing from main to pushdest"
        hg -R main push pushdest $@
    fi
    echo "## post push state"
    echo "# obstore: main"
    hg -R main     debugobsolete | sort
    echo "# obstore: pushdest"
    hg -R pushdest debugobsolete | sort
    echo "# obstore: pulldest"
    hg -R pulldest debugobsolete | sort
    if [ -n "$target" ]; then
        echo "## pulling \"$targetnode\"" from main into pulldest
        hg -R pulldest pull -r $targetnode $@ main
    else
        echo "## pulling from main into pulldest"
        hg -R pulldest pull main $@
    fi
    echo "## post pull state"
    echo "# obstore: main"
    hg -R main     debugobsolete | sort
    echo "# obstore: pushdest"
    hg -R pushdest debugobsolete | sort
    echo "# obstore: pulldest"
    hg -R pulldest debugobsolete | sort

    cd ..

}