annotate tests/testlib/exchange-obsmarker-util.sh @ 32697:19b9fc40cc51

revlog: skeleton support for version 2 revlogs

There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.

It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.

This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.

An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.

To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.

Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.

There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.

#!/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=all

[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 ..

}