Class: VoldemortJsonBinarySerializer

Inherits:
Object
  • Object
show all
Defined in:
lib/voldemort-serializer.rb

Constant Summary collapse

BYTE_MIN_VAL = 
-128
SHORT_MIN_VAL = 
-32768
SHORT_MAX_VAL = 
2 ** 15 - 1
INT_MIN_VAL = 
-2147483648
LONG_MIN_VAL = 
-9223372036854775808
FLOAT_MIN_VAL = 
2 ** -149
DOUBLE_MIN_VAL = 
2 ** -1074

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type_def_versions) ⇒ VoldemortJsonBinarySerializer

Returns a new instance of VoldemortJsonBinarySerializer.



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# File 'lib/voldemort-serializer.rb', line 16

def initialize(type_def_versions)
  @has_version = true
  @type_def_versions = {}
  
  # convert versioned json strings to ruby objects
  type_def_versions.each_pair do |version, json_type_def_version|
    @type_def_versions[version.to_i] = get_type_def(json_type_def_version)
  end
end

Instance Attribute Details

#has_version ⇒ Object

Returns the value of attribute has_version.



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# File 'lib/voldemort-serializer.rb', line 5

def has_version
  @has_version
end

#type_def_versions ⇒ Object

Returns the value of attribute type_def_versions.



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# File 'lib/voldemort-serializer.rb', line 6

def type_def_versions
  @type_def_versions
end

Instance Method Details

#get_type_def(json_type_def_version) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 33

def get_type_def(json_type_def_version)
  # replace all single quotes with " since the JSON parser wants it this way
  json_type_def_version = json_type_def_version.gsub(/\'/, '"')
  
  if((json_type_def_version =~ /[\{\[]/) == 0)
    # check if the json is a list or string, since these are 
    # the only ones that JSON.parse() will work with
    return JSON.parse(json_type_def_version)
  else
    # otherwise it's a primitive, so just strip the quotes
    return json_type_def_version.gsub(/\"/, '')
  end
end

#read(bytes, type) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 335

def read(bytes, type)
  if(type.kind_of? Hash)
    return read_map(bytes, type)
  elsif(type.kind_of? Array)
    return read_list(bytes, type)
  else
    case(type)
      when 'string'
        return read_bytes(bytes)
      when 'int8'
        return read_int8(bytes)
      when 'int16'
        return read_int16(bytes)
      when 'int32'
        return read_int32(bytes)
      when 'int64'
        return read_int64(bytes)
      when 'float32'
        return read_float32(bytes)
      when 'float64'
        return read_float64(bytes)
      when 'date'
        return read_date(bytes)
      when 'bytes'
        return read_bytes(bytes)
      when 'boolean'
        return read_boolean(bytes)
      # TODO default throw unknown type exception
    end
  end
end

#read_boolean(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 397

def read_boolean(bytes)
  b = read_slice(1, bytes).unpack('c').first
  
  if(b < 0)
    return nil
  elsif(b == 0)
    return false
  else
    return true
  end
end

#read_bytes(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 483

def read_bytes(bytes)
  size = read_int16(bytes)
  
  if(size < 0)
    return nil
  else
    return read_slice(size, bytes)
  end
end

#read_date(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 473

def read_date(bytes)
  d = read_int64(bytes)
  
  if(d != nil)
    d = Time.at((d / 1000).to_i, d % 1000)
  end
  
  return d
end

#read_float32(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 453

def read_float32(bytes)
  f = read_slice(4, bytes).unpack("g").first.to_f
  
  if(f == FLOAT_MIN_VAL)
    return nil
  end
  
  return f
end

#read_float64(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 463

def read_float64(bytes)
  d = read_slice(8, bytes).unpack("G").first.to_f
  
  if(d == DOUBLE_MIN_VAL)
    return nil
  end
  
  return d
end

#read_int16(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 419

def read_int16(bytes)
  s = to_signed(read_slice(2, bytes).unpack("n").first, 16)

  if(s == SHORT_MIN_VAL)
    return nil
  end
  
  return s
end

#read_int32(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 429

def read_int32(bytes)
  # reverse here to switch little endian to big endian
  # this is because pack('N') is choking on 'bigint', wtf?
  i = read_slice(4, bytes).reverse.unpack("i").first.to_i
  
  if(i == INT_MIN_VAL)
    return nil
  end
  
  return i
end

#read_int64(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 441

def read_int64(bytes)
  # reverse here to switch little endian to big endian
  # this is because pack('N') is choking on 'bigint', wtf?
  l = read_slice(8, bytes).reverse.unpack("q").first.to_i
  
  if(l == LONG_MIN_VAL)
    return nil
  end
  
  return l
end

#read_int8(bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 409

def read_int8(bytes)
  b = read_slice(1, bytes).unpack("c").first.to_i
  
  if(b == BYTE_MIN_VAL)
    return nil
  end
  
  return b
end

#read_list(bytes, type) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 384

def read_list(bytes, type)
  size = read_int16(bytes)
  if(size < 0)
    return nil
  else
    object = []
    
    size.times { object << read(bytes, type.first) }
    
    return object
  end
end

#read_map(bytes, type) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 367

def read_map(bytes, type)
  # convert to char to string, and string to int
  if(read_slice(1, bytes).unpack('c').to_s.to_i == -1)
    return nil
  else
    object = {}
    
    type.sort.each do |type_pair|
      name = type_pair.first
      sub_type = type_pair.last
      object[name] = read(bytes, sub_type)
    end
    
    return object
  end
end

#read_slice(length, bytes) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 47

def read_slice(length, bytes)
  substr = bytes[0, length]
  bytes.slice!(0..length - 1)
  return substr
end

#to_bytes(object) ⇒ Object

handle serialization



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# File 'lib/voldemort-serializer.rb', line 55

def to_bytes(object)
  bytes = ''
  newest_version = 0 # TODO get highest number from map
  type_def = @type_def_versions[newest_version]
  
  if(@has_version)
    bytes << newest_version.chr
  end
  
  bytes << write(object, type_def)
  
  return bytes
end

#to_object(bytes) ⇒ Object

handle deserialization



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# File 'lib/voldemort-serializer.rb', line 319

def to_object(bytes)
  version = 0
  
  if(@has_version)
    version = read_slice(1, bytes).to_i
  end
  
  type = @type_def_versions[version]
  
  if(type == nil)
    # TODO throw exception here
  end
  
  return read(bytes, type)
end

#to_signed(unsigned, bits) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 26

def to_signed(unsigned, bits)
  max_unsigned = 2 ** bits
  max_signed = 2 ** (bits - 1)
  to_signed = proc { |n| (n >= max_signed) ? n - max_unsigned : n }
  return to_signed[unsigned]
end

#write(object, type) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 69

def write(object, type)
  bytes = ''
  
  if(type.kind_of? Hash)
  	if(object != nil && !object.kind_of?(Hash))
  	  # TODO throw exception
  	else
  	  bytes << write_map(object, type)
  	end
  elsif(type.kind_of? Array)
  	if(object != nil && !object.kind_of?(Array))
  	  # TODO throw exception
  	else
  	  bytes << write_list(object, type)
  	end
  else
    case(type)
      when 'string'
        bytes << write_string(object)
      when 'int8'
        bytes << write_int8(object)
      when 'int16'
        bytes << write_int16(object)
      when 'int32'
        bytes << write_int32(object)
      when 'int64'
        bytes << write_int64(object)
      when 'float32'
        bytes << write_float32(object)
      when 'float64'
        bytes << write_float64(object)
      when 'date'
        bytes << write_date(object)
      when 'bytes'
        bytes << write_bytes(object)
      when 'boolean'
        bytes << write_boolean(object)
      else
        # TODO throw unsupported type exception
    end
  end
  
  if(bytes == '')
    return nil
  end
  
  return bytes
end

#write_boolean(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 118

def write_boolean(object)
  bytes = ''
  
  if(object == nil)
    bytes << [BYTE_MIN_VAL].pack('c')
  elsif(object)
    bytes << [0x1].pack('c')
  else
    bytes << [0x0].pack('c')
  end
  
  return bytes
end

#write_bytes(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 252

def write_bytes(object)
  bytes = ''
  
  if(object == nil)
    bytes << write_int16(-1)
  elsif(object.length < SHORT_MAX_VAL)
    bytes << write_int16(object.length)
    bytes << object
  else
    # TODO throw "length too long to serialize" exception
  end
  
  return bytes
end

#write_date(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 236

def write_date(object)
  bytes = ''
  
  if(object == LONG_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      bytes << write_int64(nil)
    else
      bytes << write_int64((object.to_f * 1000).to_i)
    end
  end
  
  return bytes
end

#write_float32(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 204

def write_float32(object)
  bytes = ''
  
  if(object == FLOAT_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      object = FLOAT_MIN_VAL
    end
    
    bytes << [object].pack('g')
  end
  
  return bytes
end

#write_float64(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 220

def write_float64(object)
  bytes = ''
  
  if(object == DOUBLE_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      object = DOUBLE_MIN_VAL
    end
    
    bytes << [object].pack('G')
  end
  
  return bytes
end

#write_int16(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 152

def write_int16(object)
  bytes = ''
  
  if(object == SHORT_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      object = SHORT_MIN_VAL
    end
    
    bytes << [object].pack('n')
  end
  
  return bytes
end

#write_int32(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 168

def write_int32(object)
  bytes = ''
  
  if(object == INT_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      object = INT_MIN_VAL
    end
    
    # reverse here to switch little endian to big endian
    # this is because pack('N') is choking on 'bigint', wtf?
    bytes << [object].pack('i').reverse
  end
  
  return bytes
end

#write_int64(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 186

def write_int64(object)
  bytes = ''
  
  if(object == LONG_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      object = LONG_MIN_VAL
    end
    
    # reverse here to switch little endian to big endian
    # this is because pack('N') is choking on 'bigint', wtf?
    bytes << [object].pack('q').reverse
  end
  
  return bytes
end

#write_int8(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 136

def write_int8(object)
  bytes = ''
  
  if(object == BYTE_MIN_VAL)
    # TODO throw underflow exception
  else
    if(object == nil)
      object = BYTE_MIN_VAL
    end
    
    bytes << [object].pack('c')
  end
  
  return bytes
end

#write_list(object, type) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 294

def write_list(object, type)
  bytes = ''
  
  if(type.length != 1)
    # TODO throw new exception (expected single type in list)
  else
    entry_type = type.first
    
    if(object == nil)
      bytes << write_int16(-1)
    elsif(object.length < SHORT_MAX_VAL)
      bytes << write_int16(object.length)
      object.each do |o|
        bytes << write(o, entry_type)
      end
    else
      # TODO throw serialization exception
    end
  end
  
  return bytes
end

#write_map(object, type) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 267

def write_map(object, type)
  bytes = ''
  
  if(object == nil)
    bytes << [-1].pack('c')
  else
    bytes << [1].pack('c')
    
    if(object.length != type.length)
      # TODO throw exception here.. invalid map serialization, expected: but got 
    else
      type.sort.each do |type_pair|
        key = type_pair.first
        subtype = type_pair.last
        
        if(!object.has_key? key)
          # TODO throw "missing property exception"
        else
          bytes << write(object[key], subtype)
        end
      end
    end
  end
  
  return bytes
end

#write_string(object) ⇒ Object 



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# File 'lib/voldemort-serializer.rb', line 132

def write_string(object)
  return write_bytes(object)
end