The test runs get, select, pairs space methods with various arguments in
a loop and prints the average method run time in nanoseconds (lower is
better).

Usage:

  tarantool box_select.lua

Output format:

  <test-case> <run-time>

Example:

  $ tarantool box_select.lua --pattern 'get|select_%d$'
  get_0 155
  get_1 240
  select_0 223
  select_1 335
  select_5 2321

Options:

  --pattern <string>  run only tests matching the pattern; use '|'
                      to specify more than one pattern, for example,
                      'get|select'
  --read_view         use a read view (EE only)

Apart from the test, this patch also adds a script that compares test
results:

  $ tarantool box_select.lua --pattern get > base
  $ tarantool box_select.lua --pattern get > patched1
  $ tarantool box_select.lua --pattern get > patched2
  $ tarantool compare.lua base patched1 patched2
         base          patched1          patched2
  get_0   149       303 (+103%)       147 (-  1%)
  get_1   239       418 (+ 74%)       238 (-  0%)

NO_DOC=perf test
NO_TEST=perf test
NO_CHANGELOG=perf test