print_tps_counter.sh

#!/bin/bash
export SCRIPT_DIR=$( cd "$( dirname "$0" )" && pwd )
source ${SCRIPT_DIR}/config/log_config

source ${SCRIPT_DIR}/lib/minecraft_server_control.sh
source ${SCRIPT_DIR}/lib/log_utils.sh

# Path to file storing the last TPS value
TPS_LAST_VALUE_FILE_PATH=${SCRIPT_DIR}/data/last_tps

# Should the script run the /tps command?
# This may be set to false if the server wrapper (i.e. AMP) periodically runs the /tps command already.
TPS_RUN_COMMAND=true

# Number of seconds to wait between sending the /tps command and searching its output
# Set this to 0 if TPS_RUN_COMMAND is false
TPS_DELAY_IN_SECONDS=2

# How many lines back should we search for the /tps output in the Minecraft server log?
TPS_SEARCH_NUMBER_OF_LINES=100

# Regex to search for the /tps output
TPS_OUTPUT_LINE_REGEX="\[⚡\] TPS from last 5s, 10s, 1m, 5m, 15m:"

# Regex to get the latest TPS value
TPS_VALUE_REGEX="[0-9]+\.[0-9]+"

# Minimum threshold for good TPS
TPS_GOOD_THRESHOLD=18

# Minimum threshold for ok TPS
TPS_OK_THRESHOLD=15

get_tps_line()
{
  get_line_after_last_matching_line "${TPS_OUTPUT_LINE_REGEX}" "${LATEST_LOG_PATH}" ${TPS_SEARCH_NUMBER_OF_LINES}
}

get_tps_value()
{
  # tps_index can be 1 to 5, indicating which TPS value to use:
  # 1: Last 5 seconds
  # 2: Last 10 seconds
  # 3: Last 1 minute
  # 4: Last 5 minutes
  # 5: Last 15 minutes
  local tps_index=$1

  get_tps_line | grep -E -o "${TPS_VALUE_REGEX}" | head -${tps_index} | tail -1
}

print_tps_counter()
{
  if ${TPS_RUN_COMMAND}; then
    run_minecraft_command "tps"
  fi

  sleep ${TPS_DELAY_IN_SECONDS}
  local current_tps_value="$(get_tps_value 5)"
  local last_tps_value="$(cat $TPS_LAST_VALUE_FILE_PATH)"

  local color="white"
  local change="(?)"

  if [[ -z "${current_tps_value}" ]]; then
    current_tps_value="N/A"
    color="gray"
  else
    if [[ $(echo "${current_tps_value} >= ${TPS_GOOD_THRESHOLD}" | bc -l) -eq 1 ]]; then
      color="green"
    elif [[ $(echo "${current_tps_value} >= ${TPS_OK_THRESHOLD}" | bc -l) -eq 1 ]]; then
      color="yellow"
    else
      color="red"
    fi

    if [[ $(echo "${current_tps_value} > ${last_tps_value}" | bc -l) -eq 1 ]]; then
      change="(+)"
    elif [[ $(echo "${current_tps_value} < ${last_tps_value}" | bc -l) -eq 1 ]]; then
      change="(-)"
    else
      change="(=)"
    fi
  fi

  echo ${current_tps_value} > ${TPS_LAST_VALUE_FILE_PATH}

  tellraw_in_minecraft "[Server] Average TPS in last 15 min: ${current_tps_value} ${change}" "${color}" "bold,italic"
}

# Only run this script if it is run directly
running_script=$( basename ${0#~} )
this_script=$( basename ${BASH_SOURCE} )

if [[ ${running_script} = ${this_script} ]]; then
  print_tps_counter $1
fi