#!/bin/bash
# REQUIRE: db_bench binary exists in the current directory

function main {
  commit=${1:-"origin/master"}
  test_root_dir=${2:-"/tmp/rocksdb/regression_test"}

  init_arguments

  checkout_rocksdb $commit
  build_db_bench
  setup_test_directory

  # an additional dot indicates we share same env variables
  run_db_bench "fillseq" 0
  run_db_bench "overwrite"
  run_db_bench "readrandom"
  run_db_bench "readwhilewriting"
  run_db_bench "deleterandom"
  run_db_bench "seekrandom"
  run_db_bench "seekrandomwhilewriting"

  echo ""
  echo "Benchmark completed!  Results are available in $RESULT_PATH"
}

############################################################################
function init_arguments {
  K=1024
  M=$((1024 * K))
  G=$((1024 * M))

  current_time=$(date +"%F-%H:%M:%S")
  RESULT_PATH=${4:-"/tmp/rocksdb/regression/results/$current_time"}
  COMMIT_ID=`git log | head -n1 | cut -c 8-`
  SUMMARY_FILE="$RESULT_PATH/SUMMARY.csv"

  DB_PATH=${2:-"/tmp/rocksdb/regression/db/"}
  WAL_PATH=${3:-"/tmp/rocksdb/regression/wal/"}
  NUM_THREADS=${NUM_THREADS:-16}
  NUM_KEYS=${NUM_KEYS:-$((1 * G))}
  KEY_SIZE=${KEY_SIZE:-100}
  VALUE_SIZE=${VALUE_SIZE:-900}
  CACHE_SIZE=${CACHE_SIZE:-$((1 * G))}
  STATISTICS=${STATISTICS:-0}
  COMPRESSION_RATIO=${COMPRESSION_RATIO:-0.5}
  HISTOGRAM=${HISTOGRAM:-1}
  STATS_PER_INTERVAL=${STATS_PER_INTERVAL:-1}
  STATS_INTERVAL_SECONDS=${STATS_INTERVAL_SECONDS:-60}
  MAX_BACKGROUND_FLUSHES=${MAX_BACKGROUND_FLUSHES:-4}
  MAX_BACKGROUND_COMPACTIONS=${MAX_BACKGROUND_COMPACTIONS:-16} 
  SEEK_NEXTS=${SEEK_NEXTS:-10}
  SEED=${SEED:-$( date +%s )}
}

# $1 --- benchmark name
# $2 --- use_existing_db (optional)
function run_db_bench {
  USE_EXISTING_DB=${2:-1}
  echo ""
  echo "======================================================================="
  echo "Benchmark $1"
  echo "======================================================================="
  echo ""
  db_bench_error=0
  cmd="(./db_bench --benchmarks=$1 --db=$DB_PATH --wal_dir=$WAL_PATH \
      --use_existing_db=$USE_EXISTING_DB \
      --threads=$NUM_THREADS \
      --num=$NUM_KEYS \
      --key_size=$KEY_SIZE \
      --value_size=$VALUE_SIZE \
      --cache_size=$CACHE_SIZE \
      --statistics=$STATISTICS \
      --compression_ratio=$COMPRESSION_RATIO \
      --histogram=$HISTOGRAM \
      --seek_nexts=$SEEK_NEXTS \
      --stats_per_interval=$STATS_PER_INTERVAL \
      --stats_interval_seconds=$STATS_INTERVAL_SECONDS \
      --max_background_flushes=$MAX_BACKGROUND_FLUSHES \
      --max_background_compactions=$MAX_BACKGROUND_COMPACTIONS \
      --seed=$SEED \
      2>&1 || db_bench_error=1) | tee -a $RESULT_PATH/$1"
  echo $cmd
  eval $cmd
  exit_on_error $db_bench_error

  update_report "$1" "$RESULT_PATH/$1"
}

# $1 --- name of the benchmark
# $2 --- the filename of the output log of db_bench
function update_report {
  main_result=`cat $2 | grep $1`
  perc_statement=`cat $2 | grep Percentile`

  # Obtain micros / op
  main_pattern="$1"'[[:blank:]]+:[[:blank:]]+([0-9\.]+)[[:blank:]]+micros/op'
  [[ $main_result =~ $main_pattern ]]
  micros_op=${BASH_REMATCH[1]}
  
  # Obtain percentile information
  perc_pattern='Percentiles: P50: ([0-9\.]+) P75: ([0-9\.]+) P99: ([0-9\.]+) P99.9: ([0-9\.]+) P99.99: ([0-9\.]+)'
  [[ $perc_statement =~ $perc_pattern ]]

  perc[0]=${BASH_REMATCH[1]}  # p50
  perc[1]=${BASH_REMATCH[2]}  # p75
  perc[2]=${BASH_REMATCH[3]}  # p99
  perc[3]=${BASH_REMATCH[4]}  # p99.9
  perc[4]=${BASH_REMATCH[5]}  # p99.99

  printf "$COMMIT_ID, %30s, %10.2f, %10.2f, %10.2f, %10.2f, %10.2f, %10.2f\n" \
      $1 $micros_op ${perc[0]} ${perc[1]} ${perc[2]} ${perc[3]} ${perc[4]} \
      >> $SUMMARY_FILE 
  exit_on_error $?
}

function exit_on_error {
  if [ $1 -ne 0 ]; then
    echo ""
    echo "ERROR: Benchmark did not complete successfully. " \
         "Partial results are output to $RESULT_PATH"
    echo "ERROR" >> $SUMMARY_FILE
    exit $1
  fi
}

function checkout_rocksdb {
  echo "Checking out commit $1 ..."

  git fetch --all
  exit_on_error $?

  git checkout $1
  exit_on_error $?
}

function build_db_bench {
  echo "Building db_bench ..."

  make clean
  exit_on_error $?

  DEBUG_LEVEL=0 make db_bench -j32
  exit_on_error $?
}

function setup_test_directory {
  echo "Deleting old regression test directories and creating new ones"

  rm -rf "$DB_PATH"
  exit_on_error $?

  rm -rf "$WAL_PATH"
  exit_on_error $?

  rm -rf "$RESULT_PATH"
  exit_on_error $?

  mkdir -p "$DB_PATH"
  exit_on_error $?

  mkdir -p "$WAL_PATH"
  exit_on_error $?

  mkdir -p "$RESULT_PATH"
  exit_on_error $?

  printf "%40s, %30s, %10s, %10s, %10s, %10s, %10s, %10s\n" \
      "commit id" "benchmark" "ms-per-op" "p50" "p75" "p99" "p99.9" "p99.99" \
       $micros_op ${perc[0]} ${perc[1]} ${perc[2]} ${perc[3]} ${perc[4]} \
      >> $SUMMARY_FILE 
}

############################################################################

main $@