fun nextTag()

in crumb-compiler/src/main/kotlin/com/uber/crumb/internal/wire/ProtoReader.kt [132:188]
48 lines of code
9 McCabe index (conditional complexity)

  fun nextTag(): Int {
    if (state == STATE_PACKED_TAG) {
      state = STATE_LENGTH_DELIMITED
      return tag
    } else if (state != STATE_TAG) {
      throw IllegalStateException("Unexpected call to nextTag()")
    }

    loop@ while (pos < limit && !source.exhausted()) {
      val tagAndFieldEncoding = internalReadVarint32()
      if (tagAndFieldEncoding == 0) throw ProtocolException("Unexpected tag 0")

      tag = tagAndFieldEncoding shr TAG_FIELD_ENCODING_BITS
      when (val groupOrFieldEncoding = tagAndFieldEncoding and FIELD_ENCODING_MASK) {
        STATE_START_GROUP -> {
          skipGroup(tag)
          continue@loop
        }

        STATE_END_GROUP -> throw ProtocolException("Unexpected end group")

        STATE_LENGTH_DELIMITED -> {
          nextFieldEncoding = FieldEncoding.LENGTH_DELIMITED
          state = STATE_LENGTH_DELIMITED
          val length = internalReadVarint32()
          if (length < 0) throw ProtocolException("Negative length: $length")
          if (pushedLimit != -1L) throw IllegalStateException()
          // Push the current limit, and set a new limit to the length of this value.
          pushedLimit = limit
          limit = pos + length
          if (limit > pushedLimit) throw EOFException()
          return tag
        }

        STATE_VARINT -> {
          nextFieldEncoding = FieldEncoding.VARINT
          state = STATE_VARINT
          return tag
        }

        STATE_FIXED64 -> {
          nextFieldEncoding = FieldEncoding.FIXED64
          state = STATE_FIXED64
          return tag
        }

        STATE_FIXED32 -> {
          nextFieldEncoding = FieldEncoding.FIXED32
          state = STATE_FIXED32
          return tag
        }

        else -> throw ProtocolException("Unexpected field encoding: $groupOrFieldEncoding")
      }
    }
    return -1
  }