firebird-qa/tests/bugs/core_6542_test.py

#coding:utf-8

"""
ID:          issue-6769
ISSUE:       6769
TITLE:       More efficient implementation of SUBSTRING for UTF8 character set
DESCRIPTION:
  21.11.2021. Totally re-implemented, package 'psutil' must be installed.

  We make two calls of psutil.Process(fb_pid).cpu_times() (before and after SQL code) and obtain CPU User Time
  values from each result.
  Difference between them can be considered as much more accurate performance estimation.

  We make <N_MEASURES> calls of two stored procedures with names: 'sp_ufss_test' and 'sp_utf8_test'.
  Each procedure has input argument which is required number of iterations with evaluation result of SUBSTRING.
  Number of iterations it set in variable N_COUNT_PER_MEASURE.

  Each result (difference between cpu_times().user values when apropriate procedure finishes) is added to the list.
  Finally, we evaluate MEDIAN of ratios between cpu user time which was received for UTF8 and UNICODE_FSS charsets.
  If this median is less then threshold (see var. UTF8_TO_UFSS_MAX_RATIO) then result can be considered as ACCEPTABLE.

  See also: https://psutil.readthedocs.io/en/latest/#psutil.cpu_times

  Confirmed poor performance on 3.0.8.33446 (16.04.2021) and 4.0.0.2422 (15.04.2021):
  median ratios are: 15.57 for FB-3 and 13.57 for FB-4.

  Checked on Windows, builds: 3.0.8.33527, 4.0.1.2660, 5.0.0.310.
  Result: median ratios are 1.0 in all cases.
  When heavy workload (created by another apps) exist, threshold must be increased up to ~1.3.

  21.11.2021. Checked on Linux (after installing pakage psutil):
    5.0.0.313 SS:   4.159s
    4.0.1.2668 SS:  3.786s
    3.0.8.33540 SS: 3.274s

  Old comment about other string functions (data obtained using datediff() values): // DO NOT DELETE!
  =================
    SUBSTRING remains most problematic from performance POV.
    Ratio TIME_UTF8 / TIME_UFSS  for other string functions (checked on 4.0.0.2448):
        right(..., 10):      0.4;  right(..., 8000):  0.4
        left(...,10):        1.14;  left(..., 8000):   0.3
        reverse():           0.7
        upper() / lower():   0.576 ... 0.635
        position():          0.5
        trim():              0.35
        octet_length():      1.00
        char_length():       0.632
        bit_length():        1.00
        ascii_val():         1.00
        hash():              1.00
        overlay():           0.31
        replace():           0.5
        lpad()/rpad():       0.73
  =================
JIRA:        CORE-6542
FBTEST:      bugs.core_6542
"""

import pytest
from firebird.qa import *

db = db_factory()

act = python_act('db')

expected_stdout = """
    Duration ratio: acceptable
"""

@pytest.mark.skip('FIXME: Not IMPLEMENTED')
@pytest.mark.version('>=3.0.8')
def test_1(act: Action):
    pytest.fail("Not IMPLEMENTED")

# test_script_1
#---
#
#
#  import os
#  import psutil
#  import time
#
#  os.environ["ISC_USER"] = user_name
#  os.environ["ISC_PASSWORD"] = user_password
#
#  #------------------
#  def median(lst):
#      n = len(lst)
#      s = sorted(lst)
#      return (sum(s[n//2-1:n//2+1])/2.0, s[n//2])[n % 2] if n else None
#  #------------------
#
#  ###########################
#  ###   S E T T I N G S   ###
#  ###########################
#  # How many times we call PSQL code (two stored procedures:
#  # one for performing comparisons based on LIKE, second based on SIMILAR TO statements):
#  N_MEASURES = 15
#
#  # How many iterations must be done in each of stored procedures when they work:
#  N_COUNT_PER_MEASURE = 100000
#
#  # Maximal value for MEDIAN of ratios between CPU user time when comparison was made.
#  #
#  UTF8_TO_UFSS_MAX_RATIO = 1.30
#  #############################
#
#
#  sp_cset_ddl = '''    create or alter procedure %(cset_brief)s_test (
#          n_count int = 100000
#      ) as
#          declare str1 varchar(8000) character set %(cset_name)s; -- unicode_fss /  utf8
#          declare str2 varchar(10) character set %(cset_name)s; -- unicode_fss /  utf8
#      begin
#          str1 = lpad('abcd', 8000, '--');
#          while (n_count > 0) do
#          begin
#              str2 = substring(str1 from 1 for 10);
#              n_count = n_count - 1;
#          end
#      end
#  '''
#
#  cset_map = {'sp_ufss': 'unicode_fss', 'sp_utf8': 'utf8'}
#  for k,v in cset_map.items():
#      cset_brief = k
#      cset_name = v
#      db_conn.execute_immediate( sp_cset_ddl % locals() )
#
#  db_conn.commit()
#
#  cur=db_conn.cursor()
#  cur.execute('select mon$server_pid as p from mon$attachments where mon$attachment_id = current_connection')
#
#  fb_pid = int(cur.fetchone()[0])
#  sp_time = {}
#  for i in range(0, N_MEASURES):
#      for x_charset in cset_map.keys():
#
#          fb_info_init = psutil.Process(fb_pid).cpu_times()
#          cur.callproc( x_charset + '_test', (N_COUNT_PER_MEASURE,) )
#          fb_info_curr = psutil.Process(fb_pid).cpu_times()
#
#          sp_time[ x_charset, i ]  = max(fb_info_curr.user - fb_info_init.user, 0.000001)
#
#  cur.close()
#
#
#  ratio_lst = []
#  for i in range(0, N_MEASURES):
#      ratio_lst.append( sp_time['sp_utf8',i]  / sp_time['sp_ufss',i]  )
#
#  median_ratio = median(ratio_lst)
#
#  #for p in ratio_lst:
#  #    print(p)
#  #print('median:',median_ratio)
#
#  print( 'Duration ratio: ' + ('acceptable' if median_ratio < UTF8_TO_UFSS_MAX_RATIO else 'POOR: %s, more than threshold: %s' % ( '{:9g}'.format(median_ratio), '{:9g}'.format(UTF8_TO_UFSS_MAX_RATIO) ) ) )
#  if median_ratio >= UTF8_TO_UFSS_MAX_RATIO:
#      print('Ratio statistics for %d measurements' % N_MEASURES)
#      for p in ratio_lst:
#          print( '%12.2f' % p )
#
#---