#!/bin/sh
# grep-2.21 would incur a 100x penalty for 10x increase in regexp length

# Copyright 2015-2016 Free Software Foundation, Inc.

# 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 3 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/>.

. "${srcdir=.}/init.sh"; path_prepend_ ../src

fail=0

# This test is susceptible to failure due to differences in
# system load during the two test runs, so we'll mark it as
# "expensive", making it less likely to be run by regular users.
expensive_

echo x > in || framework_failure_
# We could use seq -s '' (avoiding the tr filter), but I
# suspect some version of seq does not honor that option.
# Note that we want 10x the byte count (not line count) in the larger file.
seq 10000  20000 | tr -d '\012' > re     || framework_failure_
seq 10000 100000 | tr -d '\012' > re-10x || framework_failure_

base_ms=$(user_time_ 1 grep -f re in    ) || fail=1
b10x_ms=$(user_time_ 1 grep -f re-10x in) || fail=1

# Increasing the length of the regular expression by a factor
# of 10 should cause no more than a 10x increase in duration.
# However, we'll draw the line at 20x to avoid false-positives.
returns_ 1 expr $base_ms '<' $b10x_ms / 20 || fail=1

Exit $fail