Module: ProtocolBuffers::Encoder

Defined in:
lib/protocol_buffers/runtime/encoder.rb

Overview

:nodoc: all

Class Method Summary collapse

Class Method Details

.encode(io, message) ⇒ Object 



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# File 'lib/protocol_buffers/runtime/encoder.rb', line 12

def self.encode(io, message)
  message.validate!

  message.fields.each do |tag, field|
    next unless message.value_for_tag?(tag)

    value = message.value_for_tag(tag)
    wire_type = field.wire_type
    tag = (field.tag << 3) | wire_type

    if field.repeated?
      next if value.size == 0

      if field.packed?
        # encode packed field in a LENGTH_DELIMITED wire
        wire_type = 2
        tag = (field.tag << 3) | wire_type
        buf = ProtocolBuffers.bin_sio
        value.each { |i| serialize_field_value(buf, field.wire_type, field.serialize(i)) }
        Varint.encode(io, tag)
        Varint.encode(io, buf.size)
        io.write(buf.string)
      else
        value.each { |i| serialize_field(io, tag, wire_type, field.serialize(i)) }
      end
    else
      serialize_field(io, tag, wire_type, field.serialize(value))
    end
  end

  message.each_unknown_field do |tag_int, value|
    wire_type = tag_int & 0b111
    serialize_field(io, tag_int, wire_type, value)
  end
end

.serialize_field(io, tag, wire_type, serialized) ⇒ Object 



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# File 'lib/protocol_buffers/runtime/encoder.rb', line 48

def self.serialize_field(io, tag, wire_type, serialized)
  # write the tag
  Varint.encode(io, tag)
  self.serialize_field_value(io, wire_type, serialized)
  Varint.encode(io, tag & ~3 | 4) if wire_type == 3
end

.serialize_field_value(io, wire_type, serialized) ⇒ Object 



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# File 'lib/protocol_buffers/runtime/encoder.rb', line 55

def self.serialize_field_value(io, wire_type, serialized)
  # see comment in decoder.rb about magic numbers
  case wire_type
  when 0 # VARINT
    Varint.encode(io, serialized)
  when 1, 5 # FIXED64, FIXED32
    io.write(serialized)
  when 2 # LENGTH_DELIMITED
    Varint.encode(io, serialized.bytesize)
    io.write(serialized)
  when 3 # START_GROUP
    io.write(serialized)
  when 4 # END_GROUP: never appear
    raise(EncodeError, "Unexpected wire type END_GROUP")
  else
    raise(EncodeError, "unknown wire type: #{wire_type}")
  end
end