class Thrift::CompactProtocol

Constants

EVERYTHING_ELSE_MASK
PROTOCOL_ID
SEVEN_BIT_MASK
TSTOP
TYPE_MASK
TYPE_SHIFT_AMOUNT
VERSION
VERSION_MASK

Public Class Methods

new(transport) click to toggle source
Calls superclass method Thrift::BaseProtocol::new
    # File lib/thrift/protocol/compact_protocol.rb
 96 def initialize(transport)
 97   super(transport)
 98 
 99   @last_field = [0]
100   @boolean_value = nil
101 
102   # Pre-allocated read buffer for read_double().
103   @rbuf = "\0" * 8
104   @rbuf.force_encoding("BINARY") if @rbuf.respond_to?(:force_encoding)
105 end

Public Instance Methods

read_bool() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
298 def read_bool
299   unless @bool_value.nil?
300     bv = @bool_value
301     @bool_value = nil
302     bv
303   else
304     read_byte() == CompactTypes::BOOLEAN_TRUE
305   end
306 end
read_byte() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
308 def read_byte
309   val = trans.read_byte
310   if (val > 0x7f)
311     val = 0 - ((val - 1) ^ 0xff)
312   end
313   val
314 end
read_double() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
328 def read_double
329   trans.read_into_buffer(@rbuf, 8)
330   val = @rbuf.reverse.unpack('G').first
331   val
332 end
read_field_begin() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
246 def read_field_begin
247   type = read_byte()
248 
249   # if it's a stop, then we can return immediately, as the struct is over.
250   if (type & 0x0f) == Types::STOP
251     TSTOP
252   else
253     field_id = nil
254 
255     # mask off the 4 MSB of the type header. it could contain a field id delta.
256     modifier = (type & 0xf0) >> 4
257     if modifier == 0
258       # not a delta. look ahead for the zigzag varint field id.
259       @last_field.pop
260       field_id = read_i16()
261     else
262       # has a delta. add the delta to the last read field id.
263       field_id = @last_field.pop + modifier
264     end
265 
266     # if this happens to be a boolean field, the value is encoded in the type
267     if CompactTypes.is_bool_type?(type)
268       # save the boolean value in a special instance variable.
269       @bool_value = (type & 0x0f) == CompactTypes::BOOLEAN_TRUE
270     end
271 
272     # push the new field onto the field stack so we can keep the deltas going.
273     @last_field.push(field_id)
274     ["", CompactTypes.get_ttype(type & 0x0f), field_id]
275   end
276 end
read_i16() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
316 def read_i16
317   zig_zag_to_int(read_varint32())
318 end
read_i32() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
320 def read_i32
321   zig_zag_to_int(read_varint32())
322 end
read_i64() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
324 def read_i64
325   zig_zag_to_long(read_varint64())
326 end
read_list_begin() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
284 def read_list_begin
285   size_and_type = read_byte()
286   size = (size_and_type >> 4) & 0x0f
287   if size == 15
288     size = read_varint32()
289   end
290   type = CompactTypes.get_ttype(size_and_type)
291   [type, size]
292 end
read_map_begin() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
278 def read_map_begin
279   size = read_varint32()
280   key_and_value_type = size == 0 ? 0 : read_byte()
281   [CompactTypes.get_ttype(key_and_value_type >> 4), CompactTypes.get_ttype(key_and_value_type & 0xf), size]
282 end
read_message_begin() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
218 def read_message_begin
219   protocol_id = read_byte()
220   if protocol_id != PROTOCOL_ID
221     raise ProtocolException.new("Expected protocol id #{PROTOCOL_ID} but got #{protocol_id}")
222   end
223   
224   version_and_type = read_byte()
225   version = version_and_type & VERSION_MASK
226   if (version != VERSION)
227     raise ProtocolException.new("Expected version #{VERSION} but got #{version}");
228   end
229   
230   type = (version_and_type >> TYPE_SHIFT_AMOUNT) & 0x03
231   seqid = read_varint32()
232   messageName = read_string()
233   [messageName, type, seqid]
234 end
read_set_begin() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
294 def read_set_begin
295   read_list_begin
296 end
read_string() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
334 def read_string
335   size = read_varint32()
336   trans.read_all(size)
337 end
read_struct_begin() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
236 def read_struct_begin
237   @last_field.push(0)
238   ""
239 end
read_struct_end() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
241 def read_struct_end
242   @last_field.pop()
243   nil
244 end
write_bool(bool) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
181 def write_bool(bool)
182   type = bool ? CompactTypes::BOOLEAN_TRUE : CompactTypes::BOOLEAN_FALSE
183   unless @boolean_field.nil?
184     # we haven't written the field header yet
185     write_field_begin_internal(@boolean_field.first, @boolean_field.last, type)
186     @boolean_field = nil
187   else
188     # we're not part of a field, so just write the value.
189     write_byte(type)
190   end
191 end
write_byte(byte) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
193 def write_byte(byte)
194   @trans.write([byte].pack('c'))
195 end
write_double(dub) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
209 def write_double(dub)
210   @trans.write([dub].pack("G").reverse)
211 end
write_field_begin(name, type, id) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
125 def write_field_begin(name, type, id)
126   if type == Types::BOOL
127     # we want to possibly include the value, so we'll wait.
128     @boolean_field = [type, id]
129   else
130     write_field_begin_internal(type, id)
131   end
132   nil
133 end
write_field_begin_internal(type, id, type_override=nil) click to toggle source

The workhorse of writeFieldBegin. It has the option of doing a 'type override' of the type header. This is used specifically in the boolean field case.

    # File lib/thrift/protocol/compact_protocol.rb
140 def write_field_begin_internal(type, id, type_override=nil)
141   last_id = @last_field.pop
142   
143   # if there's a type override, use that.
144   typeToWrite = type_override || CompactTypes.get_compact_type(type)
145 
146   # check if we can use delta encoding for the field id
147   if id > last_id && id - last_id <= 15
148     # write them together
149     write_byte((id - last_id) << 4 | typeToWrite)
150   else
151     # write them separate
152     write_byte(typeToWrite)
153     write_i16(id)
154   end
155 
156   @last_field.push(id)
157   nil
158 end
write_field_stop() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
160 def write_field_stop
161   write_byte(Types::STOP)
162 end
write_i16(i16) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
197 def write_i16(i16)
198   write_varint32(int_to_zig_zag(i16))
199 end
write_i32(i32) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
201 def write_i32(i32)
202   write_varint32(int_to_zig_zag(i32))
203 end
write_i64(i64) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
205 def write_i64(i64)
206   write_varint64(long_to_zig_zag(i64))
207 end
write_list_begin(etype, size) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
173 def write_list_begin(etype, size)
174   write_collection_begin(etype, size)
175 end
write_map_begin(ktype, vtype, size) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
164 def write_map_begin(ktype, vtype, size)
165   if (size == 0)
166     write_byte(0)
167   else
168     write_varint32(size)
169     write_byte(CompactTypes.get_compact_type(ktype) << 4 | CompactTypes.get_compact_type(vtype))
170   end
171 end
write_message_begin(name, type, seqid) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
107 def write_message_begin(name, type, seqid)
108   write_byte(PROTOCOL_ID)
109   write_byte((VERSION & VERSION_MASK) | ((type << TYPE_SHIFT_AMOUNT) & TYPE_MASK))
110   write_varint32(seqid)
111   write_string(name)
112   nil
113 end
write_set_begin(etype, size) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
177 def write_set_begin(etype, size)
178   write_collection_begin(etype, size);
179 end
write_string(str) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
213 def write_string(str)
214   write_varint32(str.length)
215   @trans.write(str)
216 end
write_struct_begin(name) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
115 def write_struct_begin(name)
116   @last_field.push(0)
117   nil
118 end
write_struct_end() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
120 def write_struct_end
121   @last_field.pop
122   nil
123 end

Private Instance Methods

int_to_zig_zag(n) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
403 def int_to_zig_zag(n)
404   (n << 1) ^ (n >> 31)
405 end
long_to_zig_zag(l) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
407 def long_to_zig_zag(l)
408   # puts "zz encoded #{l} to #{(l << 1) ^ (l >> 63)}"
409   (l << 1) ^ (l >> 63)
410 end
read_varint32() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
387 def read_varint32()
388   read_varint64()
389 end
read_varint64() click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
391 def read_varint64()
392   shift = 0
393   result = 0
394   while true
395     b = read_byte()
396     result |= (b & 0x7f) << shift
397     break if (b & 0x80) != 0x80
398     shift += 7
399   end
400   result
401 end
write_collection_begin(elem_type, size) click to toggle source

Abstract method for writing the start of lists and sets. List and sets on the wire differ only by the type indicator.

    # File lib/thrift/protocol/compact_protocol.rb
346 def write_collection_begin(elem_type, size)
347   if size <= 14
348     write_byte(size << 4 | CompactTypes.get_compact_type(elem_type))
349   else
350     write_byte(0xf0 | CompactTypes.get_compact_type(elem_type))
351     write_varint32(size)
352   end
353 end
write_varint32(n) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
355 def write_varint32(n)
356   # int idx = 0;
357   while true
358     if (n & ~0x7F) == 0
359       # i32buf[idx++] = (byte)n;
360       write_byte(n)
361       break
362       # return;
363     else
364       # i32buf[idx++] = (byte)((n & 0x7F) | 0x80);
365       write_byte((n & 0x7F) | 0x80)
366       n = n >> 7
367     end
368   end
369   # trans_.write(i32buf, 0, idx);
370 end
write_varint64(n) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
375 def write_varint64(n)
376   while true
377     if (n & EVERYTHING_ELSE_MASK) == 0 #TODO need to find a way to make this into a long...
378       write_byte(n)
379       break
380     else
381       write_byte((n & SEVEN_BIT_MASK) | 0x80)
382       n >>= 7
383     end
384   end
385 end
zig_zag_to_int(n) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
412 def zig_zag_to_int(n)
413   (n >> 1) ^ -(n & 1)
414 end
zig_zag_to_long(n) click to toggle source
    # File lib/thrift/protocol/compact_protocol.rb
416 def zig_zag_to_long(n)
417   (n >> 1) ^ -(n & 1)
418 end