Benchmarking simple SQL query parsing

benchmark-query-x.rb

# frozen_string_literal: true

require 'benchmark/ips'

QUERY_NAMES = [
  "set names",
  "select",
  "insert",
  "update",
  "delete",
  "begin",
  "commit",
  "rollback",
  "savepoint",
  "release savepoint",
  "explain",
  "drop database",
  "drop table",
  "create database",
  "create table",
].freeze

MAX_QUERY_NAME_PREFIX_SIZE = QUERY_NAMES.map(&:size).max
QUERY_NAME_RE = Regexp.new("^(#{QUERY_NAMES.join('|')})")

def seq_find(q)
  QUERY_NAMES.find { |name| q.start_with?(name) }
end

def re_find(q)
  match = QUERY_NAME_RE.match(q)
  match[1] if match && match.size > 1
end

Benchmark.ips do |x|
  x.report('seq find select') { seq_find('select * from')}
  x.report('re find select') { re_find('select * from')}

  x.report('seq find explain') { seq_find('explain select * from')}
  x.report('re find explain') { re_find('explain select * from')}

  x.report('seq find <nil>') { seq_find('foo bar')}
  x.report('re find <nil>') { re_find('foo bar')}

  x.report('seq find <nil2>') { seq_find('create foo bar')}
  x.report('re find <nil2>') { re_find('create foo bar')}
end