/src/scripts/simple_thrift.rb
Ruby | 257 lines | 207 code | 40 blank | 10 comment | 12 complexity | d6f130e1fd7ab4df82b6e911e3b21a0f MD5 | raw file
Possible License(s): Apache-2.0
- #!/usr/bin/env ruby
- #
- # 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.
- #
- require 'socket'
- require 'getoptlong'
- module SimpleThrift
- VERSION_1 = 0x8001
- # message types
- CALL, REPLY, EXCEPTION = (1..3).to_a
- # value types
- STOP, VOID, BOOL, BYTE, DOUBLE, _, I16, _, I32, _, I64, STRING, STRUCT, MAP, SET, LIST = (0..15).to_a
- FORMATS = {
- BYTE => "c",
- DOUBLE => "G",
- I16 => "n",
- I32 => "N",
- }
- SIZES = {
- BYTE => 1,
- DOUBLE => 8,
- I16 => 2,
- I32 => 4,
- }
- module ComplexType
- module Extends
- def type_id=(n)
- @type_id = n
- end
- def type_id
- @type_id
- end
- end
- module Includes
- def to_i
- self.class.type_id
- end
- def to_s
- args = self.values.map { |v| self.class.type_id == STRUCT ? v.name : v.to_s }.join(", ")
- "#{self.class.name}.new(#{args})"
- end
- end
- end
- 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
- ListType = make_type(LIST, "ListType", :element_type)
- MapType = make_type(MAP, "MapType", :key_type, :value_type)
- StructType = make_type(STRUCT, "StructType", :struct_class)
- class << self
- 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, map.size ].pack("ccN") + map.map { |k, v| pack_value(type.key_type, k) + pack_value(type.value_type, v) }.join("")
- when StructType
- value._pack
- else
- [ value ].pack(FORMATS[type])
- end
- end
- 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")
- (hi << 32) | lo
- when LIST
- read_list(s)
- when MAP
- read_map(s)
- when STRUCT
- read_struct(s)
- 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
- s.read(SIZES[type]).unpack(FORMATS[type]).first
- end
- end
- 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
- 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
- def read_struct(s, struct_class=nil)
- rv = struct_class ? struct_class.new() : nil
- while true
- type = s.read(1).unpack("c").first
- return rv if type == STOP
- fid = s.read(2).unpack("n").first
- field = struct_class ? struct_class._fields.find { |f| (f.fid == fid) and (f.type.to_i == type) } : nil
- value = read_value(s, field ? field.type : type)
- rv[field.name] = value if field
- end
- end
- def read_response(s, rv_class)
- 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
- [ method_name, seq_id, read_struct(s, rv_class).rv ]
- end
- end
- ## ----------------------------------------
- class Field
- attr_accessor :name, :type, :fid
- def initialize(name, type, fid)
- @name = name
- @type = type
- @fid = fid
- end
- def pack(value)
- value.nil? ? "" : [ type.to_i, fid, SimpleThrift.pack_value(type, value) ].pack("cna*")
- end
- end
- class ThriftException < RuntimeError
- def initialize(reason)
- @reason = reason
- end
- def to_s
- "ThriftException(#{@reason.inspect})"
- end
- end
- module ThriftStruct
- module Include
- def _pack
- self.class._fields.map { |f| f.pack(self[f.name]) }.join + [ STOP ].pack("c")
- end
- end
- module Extend
- def _fields
- @fields
- end
- def _fields=(f)
- @fields = f
- end
- end
- end
- def self.make_struct(name, *fields)
- 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
- class ThriftService
- def initialize(sock)
- @sock = sock
- end
- def self._arg_structs
- @_arg_structs = {} if @_arg_structs.nil?
- @_arg_structs
- end
- def self.thrift_method(name, rtype, *args)
- arg_struct = SimpleThrift.make_struct("Args__#{self.name}__#{name}", *args)
- rv_struct = SimpleThrift.make_struct("Retval__#{self.name}__#{name}", SimpleThrift::Field.new(:rv, rtype, 0))
- _arg_structs[name.to_sym] = [ arg_struct, rv_struct ]
- arg_names = args.map { |a| a.name.to_s }.join(", ")
- class_eval "def #{name}(#{arg_names}); _proxy(:#{name}#{args.size > 0 ? ', ' : ''}#{arg_names}); end"
- end
- def _proxy(method_name, *args)
- cls = self.class.ancestors.find { |cls| cls.respond_to?(:_arg_structs) and cls._arg_structs[method_name.to_sym] }
- arg_class, rv_class = cls._arg_structs[method_name.to_sym]
- arg_struct = arg_class.new(*args)
- data = [ VERSION_1, CALL, method_name.to_s.size, method_name.to_s, 0, arg_struct._pack ].pack("nnNa*Na*")
- @sock.write(data)
- rv = SimpleThrift.read_response(@sock, rv_class)
- rv[2]
- end
- # convenience. robey is lazy.
- [[ :field, "Field.new" ], [ :struct, "StructType.new" ],
- [ :list, "ListType.new" ], [ :map, "MapType.new" ]].each do |new_name, old_name|
- class_eval "def self.#{new_name}(*args); SimpleThrift::#{old_name}(*args); end"
- end
- [ :void, :bool, :byte, :double, :i16, :i32, :i64, :string ].each { |sym| class_eval "def self.#{sym}; SimpleThrift::#{sym.to_s.upcase}; end" }
- end
- end