Module: ThriftClient::Simple

Defined in:
lib/vendor/thrift_client/simple.rb

Overview

This is a simplified form of thrift, useful for clients only, and not making any attempt to have good performance. It’s intended to be used by small command-line tools that don’t want to install a dozen ruby files.

Defined Under Namespace

Modules: ComplexType, ThriftStruct Classes: Field, ThriftException, ThriftService

Constant Summary collapse

VERSION_1 = 
0x8001
FORMATS = 
{
  BYTE => "c",
  DOUBLE => "G",
  I16 => "n",
  I32 => "N",
}
SIZES = 
{
  BYTE => 1,
  DOUBLE => 8,
  I16 => 2,
  I32 => 4,
}
ListType = 
make_type(LIST, "ListType", :element_type)
MapType = 
make_type(MAP, "MapType", :key_type, :value_type)
SetType = 
make_type(SET, "SetType", :element_type)
StructType = 
make_type(STRUCT, "StructType", :struct_class)
ExceptionStruct = 
make_struct(:ProtocolException, Field.new(:message, STRING, 1), Field.new(:type, I32, 2))
UnknownStruct = 
make_struct(:Unknown)

Class Method Summary collapse

Class Method Details

.make_exception(name, *fields) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 257

def self.make_exception(name, *fields)
  struct_class = self.make_struct(name, *fields)
  ex_class = Class.new(StandardError)

  (class << struct_class; self end).send(:define_method, :exception_class) { ex_class }
  (class << ex_class; self end).send(:define_method, :struct_class) { struct_class }

  ex_class.class_eval do
    attr_reader :struct

    def initialize
      @struct = self.class.struct_class.new
    end

    def self._fields
      struct_class._fields
    end

    def to_s
      method = [:message, :description].find {|m| struct.respond_to? m }
      struct.send method || :to_s
    end

    alias message to_s

    def method_missing(method, *args)
      struct.send(method, *args)
    end
  end

  ex_class
end

.make_struct(name, *fields) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 242

def self.make_struct(name, *fields)
  st_name = "ST_#{name.to_s.tr(':', '_')}"
  if Struct.constants.include?(st_name)
    warn "#{caller[0]}: Struct::#{st_name} is already defined; returning original class."
    Struct.const_get(st_name)
  else
    names = fields.map { |f| f.name.to_sym }
    klass = Struct.new(st_name, *names)
    klass.send(:include, ThriftStruct::Include)
    klass.send(:extend, ThriftStruct::Extend)
    klass._fields = fields
    klass
  end
end

.make_type(type_id, name, *args) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 55

def self.make_type(type_id, name, *args)
  klass = Struct.new("STT_#{name}", *args)
  klass.send(:extend, ComplexType::Extends)
  klass.send(:include, ComplexType::Includes)
  klass.type_id = type_id
  klass
end

.pack_request(method_name, arg_struct, framed, request_id = 0) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 90

def pack_request(method_name, arg_struct, framed, request_id=0)
  msg = [ VERSION_1, CALL, method_name.to_s.size, method_name.to_s, request_id, arg_struct._pack ].pack("nnNa*Na*")
  if framed
    frame = [ msg.length ].pack("N")
    frame + msg
  else
    msg
  end
end

.pack_value(type, value) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 69

def pack_value(type, value)
  case type
  when BOOL
    [ value ? 1 : 0 ].pack("c")
  when STRING
    [ value.size, value ].pack("Na*")
  when I64
    [ value >> 32, value & 0xffffffff ].pack("NN")
  when ListType
    [ type.element_type.to_i, value.size ].pack("cN") + value.map { |item| pack_value(type.element_type, item) }.join("")
  when MapType
    [ type.key_type.to_i, type.value_type.to_i, value.size ].pack("ccN") + value.map { |k, v| pack_value(type.key_type, k) + pack_value(type.value_type, v) }.join("")
  when SetType
    [ type.element_type.to_i, value.size ].pack("cN") + value.map { |item| pack_value(type.element_type, item) }.join("")
  when StructType
    value._pack
  else
    [ value ].pack(FORMATS[type])
  end
end

.read_list(s, element_type = nil) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 136

def read_list(s, element_type=nil)
  etype, len = s.read(5).unpack("cN")
  expected_type = (element_type and element_type.to_i == etype.to_i) ? element_type : etype
  rv = []
  len.times do
    rv << read_value(s, expected_type)
  end
  rv
end

.read_map(s, key_type = nil, value_type = nil) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 146

def read_map(s, key_type=nil, value_type=nil)
  ktype, vtype, len = s.read(6).unpack("ccN")
  rv = {}
  expected_key_type, expected_value_type = if key_type and value_type and key_type.to_i == ktype and value_type.to_i == vtype
    [ key_type, value_type ]
  else
    [ ktype, vtype ]
  end
  len.times do
    key = read_value(s, expected_key_type)
    value = read_value(s, expected_value_type)
    rv[key] = value
  end
  rv
end

.read_response(s, rv_class, framed) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 179

def read_response(s, rv_class, framed)
  if framed
    # unwrap frame size. dont use for now
    framesize = s.read(4).unpack("N")
  end

  version, message_type, method_name_len = s.read(8).unpack("nnN")
  method_name = s.read(method_name_len)
  seq_id = s.read(4).unpack("N").first
  if message_type == EXCEPTION
    exception = read_struct(s, ExceptionStruct)
    raise ThriftException, exception.message
  end
  response = read_struct(s, rv_class)
  raise response.ex if response.respond_to?(:ex) and response.ex
  [ method_name, seq_id, response.rv ]
end

.read_struct(s, struct_class) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 162

def read_struct(s, struct_class)
  struct = struct_class.new
  while true
    ftype = s.read(1).unpack("c").first
    return struct if ftype == STOP
    fid = s.read(2).unpack("n").first

    if field = struct_class._fields.find { |f| (f.fid == fid) and (f.type.to_i == ftype) }
      struct[field.name] = read_value(s, field.type)
    else
      $stderr.puts "Warning: Unknown struct field encountered. (recieved id: #{fid})"
      raise "Warning: Unknown struct field encountered. (recieved id: #{fid})"
      read_value(s, ftype)
    end
  end
end

.read_value(s, type) ⇒ Object 



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# File 'lib/vendor/thrift_client/simple.rb', line 100

def read_value(s, type)
  case type
  when BOOL
    s.read(1).unpack("c").first != 0
  when STRING
    len = s.read(4).unpack("N").first
    s.read(len)
  when I64
    hi, lo = s.read(8).unpack("NN")
    rv = (hi << 32) | lo
    (rv >= (1 << 63)) ? (rv - (1 << 64)) : rv
  when LIST
    read_list(s)
  when MAP
    read_map(s)
  when STRUCT
    read_struct(s, UnknownStruct)
  when ListType
    read_list(s, type.element_type)
  when MapType
    read_map(s, type.key_type, type.value_type)
  when StructType
    read_struct(s, type.struct_class)
  else
    rv = s.read(SIZES[type]).unpack(FORMATS[type]).first
    case type
    when I16
      (rv >= (1 << 15)) ? (rv - (1 << 16)) : rv
    when I32
      (rv >= (1 << 31)) ? (rv - (1 << 32)) : rv
    else
      rv
    end
  end
end