Class: AMQ::Protocol::TableValueDecoder

Inherits:
Object
  • Object
show all
Includes:
TypeConstants
Defined in:
lib/amq/protocol/table_value_decoder.rb

Constant Summary collapse

PACK_UINT32_BE =

Pack format strings use explicit endianness (available as of Ruby 1.9.3)

'N'.freeze
PACK_INT64_BE = 
'q>'.freeze
PACK_INT16_BE = 
's>'.freeze
PACK_UINT64_BE = 
'Q>'.freeze
PACK_FLOAT32 =

single precision float (native endian, matches encoder)

'f'.freeze
PACK_FLOAT64 =

big-endian double precision float

'G'.freeze
PACK_UCHAR_UINT32 = 
'CN'.freeze

Constants included from TypeConstants

AMQ::Protocol::TypeConstants::BOOLEAN_FALSE, AMQ::Protocol::TypeConstants::BOOLEAN_TRUE, AMQ::Protocol::TypeConstants::TEN, AMQ::Protocol::TypeConstants::TYPE_32BIT_FLOAT, AMQ::Protocol::TypeConstants::TYPE_64BIT_FLOAT, AMQ::Protocol::TypeConstants::TYPE_ARRAY, AMQ::Protocol::TypeConstants::TYPE_BOOLEAN, AMQ::Protocol::TypeConstants::TYPE_BYTE, AMQ::Protocol::TypeConstants::TYPE_BYTE_ARRAY, AMQ::Protocol::TypeConstants::TYPE_DECIMAL, AMQ::Protocol::TypeConstants::TYPE_HASH, AMQ::Protocol::TypeConstants::TYPE_INTEGER, AMQ::Protocol::TypeConstants::TYPE_SIGNED_16BIT, AMQ::Protocol::TypeConstants::TYPE_SIGNED_64BIT, AMQ::Protocol::TypeConstants::TYPE_STRING, AMQ::Protocol::TypeConstants::TYPE_TIME, AMQ::Protocol::TypeConstants::TYPE_VOID

Class Method Summary collapse

Class Method Details

.decode_32bit_float(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 147

def self.decode_32bit_float(data, offset)
  v = data.byteslice(offset, 4).unpack1(PACK_FLOAT32)
  offset += 4

  [v, offset]
end

.decode_64bit_float(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 155

def self.decode_64bit_float(data, offset)
  v = data.byteslice(offset, 8).unpack1(PACK_FLOAT64)
  offset += 8

  [v, offset]
end

.decode_array(data, initial_offset) ⇒ Object

API



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# File 'lib/amq/protocol/table_value_decoder.rb', line 31

def self.decode_array(data, initial_offset)
  array_length = data.byteslice(initial_offset, 4).unpack1(PACK_UINT32_BE)

  ary    = []
  offset = initial_offset + 4

  while offset <= (initial_offset + array_length)
    type, offset = decode_value_type(data, offset)

    i = case type
        when TYPE_STRING
          v, offset = decode_string(data, offset)
          v
        when TYPE_BYTE_ARRAY
          # Ruby doesn't have a direct counterpart to
          # ByteBuffer or byte[], so using a string feels
          # more appropriate than an array of fixnums
          v, offset = decode_string(data, offset)
          v
        when TYPE_INTEGER
          v, offset = decode_integer(data, offset)
          v
        when TYPE_DECIMAL
          v, offset = decode_big_decimal(data, offset)
          v
        when TYPE_TIME
          v, offset = decode_time(data, offset)
          v
        when TYPE_HASH
          v, offset = decode_hash(data, offset)
          v
        when TYPE_BOOLEAN
          v, offset = decode_boolean(data, offset)
          v
        when TYPE_BYTE
          v, offset = decode_byte(data, offset)
          v
        when TYPE_SIGNED_16BIT
          v, offset = decode_short(data, offset)
          v
        when TYPE_SIGNED_64BIT
          v, offset = decode_long(data, offset)
          v
        when TYPE_32BIT_FLOAT
          v, offset = decode_32bit_float(data, offset)
          v
        when TYPE_64BIT_FLOAT
          v, offset = decode_64bit_float(data, offset)
          v
        when TYPE_VOID
          nil
        when TYPE_ARRAY
          v, offset = decode_array(data, offset)
          v
        else
          raise ArgumentError.new("unsupported type in a table value: #{type.inspect}, do not know how to decode!")
        end

    ary << i
  end


  [ary, initial_offset + array_length + 4]
end

.decode_big_decimal(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 122

def self.decode_big_decimal(data, offset)
  decimals, raw = data.byteslice(offset, 5).unpack(PACK_UCHAR_UINT32)
  offset += 5
  v = BigDecimal(raw.to_s) * (BigDecimal(TEN) ** -decimals)

  [v, offset]
end

.decode_boolean(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 140

def self.decode_boolean(data, offset)
  byte = data.getbyte(offset)
  offset += 1
  [(byte == 1), offset]
end

.decode_byte(data, offset) ⇒ Array

Decodes/Converts a byte value from the data at the provided offset.

Parameters:

    • Binary data string

    • The offset from which to read the byte

Returns:

    • The Integer value and new offset pair



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# File 'lib/amq/protocol/table_value_decoder.rb', line 182

def self.decode_byte(data, offset)
  [data.getbyte(offset), offset + 1]
end

.decode_hash(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 168

def self.decode_hash(data, offset)
  length = data.byteslice(offset, 4).unpack1(PACK_UINT32_BE)
  v = Table.decode(data.byteslice(offset, length + 4))
  offset += 4 + length

  [v, offset]
end

.decode_integer(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 107

def self.decode_integer(data, offset)
  v = data.byteslice(offset, 4).unpack1(PACK_UINT32_BE)
  offset += 4

  [v, offset]
end

.decode_long(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 115

def self.decode_long(data, offset)
  v = data.byteslice(offset, 8).unpack1(PACK_INT64_BE)
  offset += 8
  [v, offset]
end

.decode_short(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 187

def self.decode_short(data, offset)
  v = data.byteslice(offset, 2).unpack1(PACK_INT16_BE)
  offset += 2
  [v, offset]
end

.decode_string(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 97

def self.decode_string(data, offset)
  length = data.byteslice(offset, 4).unpack1(PACK_UINT32_BE)
  offset += 4
  v = data.byteslice(offset, length)
  offset += length

  [v, offset]
end

.decode_time(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 131

def self.decode_time(data, offset)
  timestamp = data.byteslice(offset, 8).unpack1(PACK_UINT64_BE)
  v = Time.at(timestamp)
  offset += 8

  [v, offset]
end

.decode_value_type(data, offset) ⇒ Object 



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# File 'lib/amq/protocol/table_value_decoder.rb', line 163

def self.decode_value_type(data, offset)
  [data.byteslice(offset, 1), offset + 1]
end