Class: Parser::BinaryProtocol

Inherits:
Object
  • Object
show all
Defined in:
lib/proto/MPS7/parser.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(argv) ⇒ BinaryProtocol

Returns a new instance of BinaryProtocol.



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# File 'lib/proto/MPS7/parser.rb', line 7

def initialize(argv)
  @binary_file = argv[0]
end

Instance Attribute Details

#binary_file ⇒ Object

Returns the value of attribute binary_file.



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# File 'lib/proto/MPS7/parser.rb', line 5

def binary_file
  @binary_file
end

Class Method Details

.answers(calculations) ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 126

def self.answers(calculations)
  puts <<~CALCS.strip
    $#{self.monetize(calculations[:debit])} is the total amount in dollars of debits,
    $#{self.monetize(calculations[:credit])} is the total amount of dollars of credits,
    #{calculations[:started_count]} autopays were started,
    #{calculations[:ended_count]} autopays were ended,
    user ID 2456938384156277127 has a balance of $#{self.monetize(calculations['2456938384156277127'])}.
    CALCS
end

.ascii ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 11

def self.ascii
  # the artii gem creates ascii text
  `artii proto-MPS7 Parser`
end

.monetize(money) ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 122

def self.monetize(money)
  '%.2f' % money
end

Instance Method Details

#binary_data_present?(data, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/proto/MPS7/parser.rb', line 78

def binary_data_present?(data, index)
  data[index].present?
end

#credit?(data, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/proto/MPS7/parser.rb', line 86

def credit?(data, index)
  data[index].unpack("C")[0] == 1
end

#debit?(data, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/proto/MPS7/parser.rb', line 82

def debit?(data, index)
  data[index].unpack("C")[0] == 0
end

#end_autopay?(data, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/proto/MPS7/parser.rb', line 94

def end_autopay?(data, index)
  data[index].unpack("C")[0] == 3
end

#for_user_id?(record, id) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/proto/MPS7/parser.rb', line 98

def for_user_id?(record, id)
  record[2] == id
end

#parse ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 16

def parse
  begin
    contents = File.open("#{binary_file}", 'rb') { |f| f.read }
  rescue Errno::ENOENT => e
    STDERR.puts "No binary file given as an argument. Please include binary file to continue."
    exit
  end
  header = contents.unpack("a4CL>")
  # header = ["MPS7", 1, 1191182336]

  index = 0
  calculations = { :debit => BigDecimal.new(0),
                   :credit => BigDecimal.new(0),
                   :started_count => 0,
                   :ended_count => 0,
                   '2456938384156277127' => BigDecimal.new(0) }

  data = contents.bytes.slice!(9..-1).pack("C*")

  while binary_data_present?(data, index)
    # debit
    if debit?(data, index)
      record = unpack_four_fields(data, index)
      # total amount in dollars of debits
      total_dollars(calculations, :debit, record)
      # for user ID 2456938384156277127,
      if for_user_id?(record, 2456938384156277127)
        # sum the dollars of debits from the user's total balance
        user_balance(calculations, 'sum', record)
      end
      index += 21
    # credit
    elsif credit?(data, index)
      record = unpack_four_fields(data, index)
      # total amount in dollars of credits
      total_dollars(calculations, :credit, record)
      # for user ID 2456938384156277127,
      if for_user_id?(record, 2456938384156277127)
        # subtract the dollars of credits from the user's total balance
        user_balance(calculations, 'difference', record)
      end
      index += 21
    # StartAutopay
    elsif start_autopay?(data, index)
      unpack_three_fields(data, index)
      # increase the total count of how many times Autopay has been started
      calculations[:started_count] += 1
      index += 13
    # EndAutopay
    elsif end_autopay?(data, index)
      unpack_three_fields(data, index)
      # increase the total count of how many times Autopay has been ended
      calculations[:ended_count] += 1
      index += 13
    else
      STDERR.puts "Binary does not follow custom protocol."
      exit
    end
  end
  calculations
end

#start_autopay?(data, index) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/proto/MPS7/parser.rb', line 90

def start_autopay?(data, index)
  data[index].unpack("C")[0] == 2
end

#total_dollars(calculations, account, record) ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 110

def total_dollars(calculations, , record)
  calculations[] += record[3].to_d
end

#unpack_four_fields(data, index) ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 102

def unpack_four_fields(data, index)
  data[index..index + 21].unpack("CL>Q>G")
end

#unpack_three_fields(data, index) ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 106

def unpack_three_fields(data, index)
  data[index..index + 13].unpack("CL>Q>")
end

#user_balance(calculations, operator, record) ⇒ Object 



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# File 'lib/proto/MPS7/parser.rb', line 114

def user_balance(calculations, operator, record)
  if operator == 'sum'
    calculations['2456938384156277127'] += record[3].to_d
  elsif operator == 'difference'
    calculations['2456938384156277127'] -= record[3].to_d
  end
end