#!/bin/bash

tail_n_grep_with_timeout() {
    timeout=$1 match=$2 tail=$3 perl -e '
    $SIG{ALRM} = sub { exit; };
    alarm $ENV{timeout};
    my $m = $ENV{match};
    my $re = qr{$m};
    my $pid = open my $fh, q{-|}, $ENV{tail} or die "Cannot run tail: $!\n";
    while ( <$fh> ) {
        next unless $_ =~ $re;
        print;
        kill 15, $pid;
        close $fh;
        exit;
    }'
}

identify_current_pg_version() {
    pg_version="$( postgres -V | grep -E 'PostgreSQL.* [0-9]+\.[0-9]+\.[0-9]+[[:space:]]*$' | awk '{print $NF}' | cut -d. -f 1,2 )"
    if [[ -z "$pg_version" ]]
    then
        echo "Unknown PG version!" >&2
        exit 1
    fi
    pg_major_version=${pg_version%%.*}
}

prepare_test_environment() {
    killall postgres postmaster omnipitr-restore &>/dev/null
    killall -9 postgres postmaster omnipitr-restore &>/dev/null
    rm -rf data-* omnipitr
}

setup_output_formatting() {
    exec > >( perl -MPOSIX=strftime -pe 'print strftime("%Y-%m-%d %H:%M:%S %Z : ", localtime time)' )
}

generate_load() {
    count="$1"
    sql="$( seq 1 100 | sed 's/.*/select fill_me_in(0.05);/'; echo "select remove_some_rows();"; echo "vacuum;" )"
    load_generator_pids=''
    ps_ppids=''
    for i in $( seq 1 $count )
    do
        while true
        do
            psql -p 54001 -qAtX <<< "$sql"
        done &> /dev/null &
        load_generator_pids="$load_generator_pids $!"
        ps_ppids="$ps_ppids --ppid $!"
    done &> /dev/null
    disown $load_generator_pids
}

stop_load_generators() {
    psql_pids="$( ps $ps_ppids o pid= )"
    kill $load_generator_pids $psql_pids &> /dev/null
    kill -9 $load_generator_pids $psql_pids &> /dev/null
}