FileSystem vs Database

fs_vs_db.rb

require 'benchmark/ips'
require 'daybreak'
require 'dbm'
require 'fileutils'
require 'sqlite3_hash'
require 'xxhash'

class DaybreakDb
  def initialize(db_file)
    @db_file = db_file
    @store = Daybreak::DB.new(@db_file)
  end

  def []=(key, val)
    hash = XXhash.xxh32(key, 123_45)
    @store[hash] = val
  end

  def [](key)
    hash = XXhash.xxh32(key, 123_45)
    @store[hash]
  end

  def values
    @store.keys.map { |k| @store[k] }
  end

  def keys
    @store.keys
  end

  def delete(key)
    hash = XXhash.xxh32(key, 123_45)
    @store.delete(hash)
  end

  def stop
    @store.close unless @store.closed?
  end
end

class DbmDb
  @store = nil

  def initialize(db_file)
    @store = DBM.new(db_file)
  end

  def []=(key, val)
    @store[key] = val
  end

  def [](key)
    @store[key]
  end

  def values
    @store.values
  end

  def keys
    @store.keys
  end

  def delete(key)
    @store.delete(key)
  end

  def stop
    @store.close unless @store.closed?
  end
end

class Sqlite3HashDb
  def initialize(db_file)
    @store = SQLite3Hash.new(db_file)
  end

  def []=(key, val)
    hash = XXhash.xxh32(key, 123_45)
    @store[hash] = val
  end

  def [](key)
    hash = XXhash.xxh32(key, 123_45)
    @store[hash]
  end

  def key?(key)
    hash = XXhash.xxh32(key, 123_45)
    @store.key?(hash)
  end

  def delete(key)
    hash = XXhash.xxh32(key, 123_45)
    @store.delete(hash)
  end

  def stop
end

def file_hashes
  5000.times.map do
    random_string = (0...16).map { (65 + rand(26)).chr }.join
    random_filename = File.join('obj', random_string + '.depends')
    content = (0..512).map { (65 + rand(26)).chr }.join
    {name: random_filename, content: content}
  end
end

def create_files(files)
  files.each do |file|
    File.write(file[:name], file[:content], mode: 'w')
  end
end

def fill_db(db_class, db_file, files)
  FileUtils.rm_rf(db_file)
  db = db_class.new(db_file)
  files.each do |file|
    db[file[:name]] = file[:content]
  end
  db.stop
end

def fill_dbs(files)
  fill_db(DaybreakDb, 'daybreak.db', files)
  fill_db(DbmDb, 'dbm.db', files)
  fill_db(Sqlite3HashDb, 'sqlite3hash.db', files)
end

def access_files_raw(files)
  files.each do |file|
    content = File.read(file)
    puts 'blah' if content == 'blah'
  end
end

def access_files_db(files, db_class, db_file)
  db = db_class.new(db_file)
  files.each do |file|
    content = db[file]
    puts 'blah' if content == 'blah'
  end
  db.stop
end

# FileUtils.rm_rf('obj')
# Dir.mkdir('obj')
# files = file_hashes
# create_files(files)
# fill_dbs(files)

files = Dir.glob('obj/**/*')
Benchmark.ips do |x|
  x.report('raw:') { access_files_raw(files) }
  x.report('daybreakdb:') { access_files_db(files, DaybreakDb, 'daybreak.db') }
  x.report('dbmdb:') { access_files_db(files, DbmDb, 'dbm.db') }
  x.report('sqlite3hash:') { access_files_db(files, Sqlite3HashDb, 'sqlite3hash.db') }
  x.compare!
end