class SparseGen

Public Class Methods

sparse_dir(dirname, num_files = 1000, percent = 50, num_blocks = 1024, block_size = 1024) click to toggle source

# File lib/sparse-gen.rb, line 28
def self.sparse_dir(dirname, num_files = 1000,
                    percent = 50, num_blocks = 1024, block_size = 1024)
  FileUtils.mkdir_p dirname
  num_files.times do |file|
    sparse_gen_percent(File.join(dirname, "file_#{file}"),
                       percent, num_blocks, block_size)
  end
end

sparse_gen_percent(filename, percent = 50, num_blocks = 1024 * 1024, block_size = 1024) click to toggle source

# File lib/sparse-gen.rb, line 4
def self.sparse_gen_percent(filename, percent = 50,
                            num_blocks = 1024 * 1024, block_size = 1024)
  file = File.open(filename, 'wb')
  sparse_block = "\0" * block_size
  rand_string = rand(36**(block_size * 2)).to_s(36)
  puts rand_string
  (num_blocks * percent / 100).times do
    if percent <= 50 
      file.write(sparse_block)
      ((100 - percent) / percent).times do
        start = rand(0..block_size)
        file.write(rand_string[start..start+block_size-1])
      end
    else
      start = rand(0..block_size)
      file.write(rand_string[start..start+block_size-1])
      ((100 - percent) / percent).times do
        file.write(sparse_block)
      end
    end
  end
  file.close
end