Module: GoogleMapsPbDecoder

Defined in:
lib/google_maps_pb_decoder.rb,
lib/google_maps_pb_decoder/version.rb

Constant Summary collapse

VERSION = 
"1.0.0"

Class Method Summary collapse

Class Method Details

.decode(str) ⇒ Object

Original script: gist.github.com/jeteon/e71fa21c1feb48fe4b5eeec045229a0c



7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
 
# File 'lib/google_maps_pb_decoder.rb', line 7

def self.decode(str)
  parts = str.split('!').select { |s| s.size > 0 }
  root = []                      # Root elemet
  curr = root                    # Current array element being appended to
  m_stack = [root]               # Stack of "m" elements
  m_count = [parts.size]         # Number of elements to put under each level

  parts.each do |e|
    match = e.match(/\d+([a-z])(.*)/)
    if !match || match.size != 3
      raise ArgumentError, "The argument is not a valid protobuf-encoded string"
    end

    kind = match[1]
    value = match[2]

    # Decrement all the m_counts
    (0...m_count.size).each do |i|
      m_count[i] -= 1
    end

    if kind == 'm'
      new_arr = []
      m_count << value.to_i
      curr << new_arr
      m_stack << new_arr
      curr = new_arr
    else
      if kind == 'b'                                    # Assuming these are boolean
        curr << (value == '1')
      elsif kind == 'd' || kind == 'f'                  # Float or double
        curr << value.to_f
      elsif kind == 'i' || kind == 'u' || kind == 'e'   # Integer, unsigned or enum as int
        curr << value.to_i
      else                                              # Store anything else as a string
        curr << value
      end
    end

    # Pop off all the arrays that have their values already
    while m_count[m_count.size - 1] == 0
      m_stack.pop
      m_count.pop
      curr = m_stack[m_stack.size - 1]
    end
  end

  root
end