# Performance testing framework.  Each perf script starts much like
# a normal test script, except it sources this library instead of
# test-lib.sh.  See t/perf/README for documentation.
#
# Copyright (c) 2011 Thomas Rast
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see http://www.gnu.org/licenses/ .

# These variables must be set before the inclusion of test-lib.sh below,
# because it will change our working directory.
TEST_DIRECTORY=$(pwd)/..
TEST_OUTPUT_DIRECTORY=$(pwd)

TEST_NO_CREATE_REPO=t
TEST_NO_MALLOC_CHECK=t

. ../test-lib.sh

# Variables from test-lib that are normally internal to the tests; we
# need to export them for test_perf subshells
export TEST_DIRECTORY TRASH_DIRECTORY GIT_BUILD_DIR GIT_TEST_CMP

MODERN_GIT=$GIT_BUILD_DIR/bin-wrappers/git
export MODERN_GIT

perf_results_dir=$TEST_OUTPUT_DIRECTORY/test-results
test -n "$GIT_PERF_SUBSECTION" && perf_results_dir="$perf_results_dir/$GIT_PERF_SUBSECTION"
mkdir -p "$perf_results_dir"
rm -f "$perf_results_dir"/$(basename "$0" .sh).subtests

die_if_build_dir_not_repo () {
        if ! ( cd "$TEST_DIRECTORY/.." &&
                    git rev-parse --build-dir >/dev/null 2>&1 ); then
                error "No $1 defined, and your build directory is not a repo"
        fi
}

if test -z "$GIT_PERF_REPO"; then
        die_if_build_dir_not_repo '$GIT_PERF_REPO'
        GIT_PERF_REPO=$TEST_DIRECTORY/..
fi
if test -z "$GIT_PERF_LARGE_REPO"; then
        die_if_build_dir_not_repo '$GIT_PERF_LARGE_REPO'
        GIT_PERF_LARGE_REPO=$TEST_DIRECTORY/..
fi

test_perf_do_repo_symlink_config_ () {
        test_have_prereq SYMLINKS || git config core.symlinks false
}

test_perf_create_repo_from () {
        test "$#" = 2 ||
        BUG "not 2 parameters to test-create-repo"
        repo="$1"
        source="$2"
        source_git="$("$MODERN_GIT" -C "$source" rev-parse --git-dir)"
        objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
        mkdir -p "$repo/.git"
        (
                cd "$source" &&
                { cp -Rl "$objects_dir" "$repo/.git/" 2>/dev/null ||
                        cp -R "$objects_dir" "$repo/.git/"; } &&
                for stuff in "$source_git"/*; do
                        case "$stuff" in
                                */objects|*/hooks|*/config|*/commondir)
                                        ;;
                                *)
                                        cp -R "$stuff" "$repo/.git/" || exit 1
                                        ;;
                        esac
                done
        ) &&
        (
                cd "$repo" &&
                "$MODERN_GIT" init -q &&
                test_perf_do_repo_symlink_config_ &&
                mv .git/hooks .git/hooks-disabled 2>/dev/null &&
                if test -f .git/index.lock
                then
                        # We may be copying a repo that can't run "git
                        # status" due to a locked index. Since we have
                        # a copy it's fine to remove the lock.
                        rm .git/index.lock
                fi
        ) || error "failed to copy repository '$source' to '$repo'"
}

# call at least one of these to establish an appropriately-sized repository
test_perf_fresh_repo () {
        repo="${1:-$TRASH_DIRECTORY}"
        "$MODERN_GIT" init -q "$repo" &&
        (
                cd "$repo" &&
                test_perf_do_repo_symlink_config_
        )
}

test_perf_default_repo () {
        test_perf_create_repo_from "${1:-$TRASH_DIRECTORY}" "$GIT_PERF_REPO"
}
test_perf_large_repo () {
        if test "$GIT_PERF_LARGE_REPO" = "$GIT_BUILD_DIR"; then
                echo "warning: \$GIT_PERF_LARGE_REPO is \$GIT_BUILD_DIR." >&2
                echo "warning: This will work, but may not be a sufficiently large repo" >&2
                echo "warning: for representative measurements." >&2
        fi
        test_perf_create_repo_from "${1:-$TRASH_DIRECTORY}" "$GIT_PERF_LARGE_REPO"
}
test_checkout_worktree () {
        git checkout-index -u -a ||
        error "git checkout-index failed"
}

# Performance tests should never fail.  If they do, stop immediately
immediate=t

# Perf tests require GNU time
case "$(uname -s)" in Darwin) GTIME="${GTIME:-gtime}";; esac
GTIME="${GTIME:-/usr/bin/time}"

test_run_perf_ () {
        test_cleanup=:
        test_export_="test_cleanup"
        export test_cleanup test_export_
        "$GTIME" -f "%E %U %S" -o test_time.$i "$SHELL" -c '
. '"$TEST_DIRECTORY"/test-lib-functions.sh'
test_export () {
        [ $# != 0 ] || return 0
        test_export_="$test_export_\\|$1"
        shift
        test_export "$@"
}
'"$1"'
ret=$?
set | sed -n "s'"/'/'\\\\''/g"';s/^\\($test_export_\\)/export '"'&'"'/p" >test_vars
exit $ret' >&3 2>&4
        eval_ret=$?

        if test $eval_ret = 0 || test -n "$expecting_failure"
        then
                test_eval_ "$test_cleanup"
                . ./test_vars || error "failed to load updated environment"
        fi
        if test "$verbose" = "t" && test -n "$HARNESS_ACTIVE"; then
                echo ""
        fi
        return "$eval_ret"
}

test_wrapper_ () {
        test_wrapper_func_=$1; shift
        test_start_
        test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
        test "$#" = 2 ||
        BUG "not 2 or 3 parameters to test-expect-success"
        export test_prereq
        if ! test_skip "$@"
        then
                base=$(basename "$0" .sh)
                echo "$test_count" >>"$perf_results_dir"/$base.subtests
                echo "$1" >"$perf_results_dir"/$base.$test_count.descr
                base="$perf_results_dir"/"$PERF_RESULTS_PREFIX$(basename "$0" .sh)"."$test_count"
                "$test_wrapper_func_" "$@"
        fi

        test_finish_
}

test_perf_ () {
        if test -z "$verbose"; then
                printf "%s" "perf $test_count - $1:"
        else
                echo "perf $test_count - $1:"
        fi
        for i in $(test_seq 1 $GIT_PERF_REPEAT_COUNT); do
                say >&3 "running: $2"
                if test_run_perf_ "$2"
                then
                        if test -z "$verbose"; then
                                printf " %s" "$i"
                        else
                                echo "* timing run $i/$GIT_PERF_REPEAT_COUNT:"
                        fi
                else
                        test -z "$verbose" && echo
                        test_failure_ "$@"
                        break
                fi
        done
        if test -z "$verbose"; then
                echo " ok"
        else
                test_ok_ "$1"
        fi
        "$TEST_DIRECTORY"/perf/min_time.perl test_time.* >"$base".times
}

test_perf () {
        test_wrapper_ test_perf_ "$@"
}

test_size_ () {
        say >&3 "running: $2"
        if test_eval_ "$2" 3>"$base".size; then
                test_ok_ "$1"
        else
                test_failure_ "$@"
        fi
}

test_size () {
        test_wrapper_ test_size_ "$@"
}

# We extend test_done to print timings at the end (./run disables this
# and does it after running everything)
test_at_end_hook_ () {
        if test -z "$GIT_PERF_AGGREGATING_LATER"; then
                ( cd "$TEST_DIRECTORY"/perf && ./aggregate.perl $(basename "$0") )
        fi
}

test_export () {
        export "$@"
}