1 /*
2 * Copyright 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "packet/fragmenting_inserter.h"
18
19 #undef NDEBUG
20 #include <cassert>
21
22 namespace bluetooth {
23 namespace packet {
24
FragmentingInserter(size_t mtu,std::back_insert_iterator<std::vector<std::unique_ptr<RawBuilder>>> iterator)25 FragmentingInserter::FragmentingInserter(
26 size_t mtu, std::back_insert_iterator<std::vector<std::unique_ptr<RawBuilder>>> iterator)
27 : BitInserter(to_construct_bit_inserter_),
28 mtu_(mtu),
29 curr_packet_(std::make_unique<RawBuilder>(mtu)),
30 iterator_(iterator) {}
31
insert_bits(uint8_t byte,size_t num_bits)32 void FragmentingInserter::insert_bits(uint8_t byte, size_t num_bits) {
33 assert(curr_packet_ != nullptr);
34 size_t total_bits = num_bits + num_saved_bits_;
35 uint16_t new_value =
36 static_cast<uint8_t>(saved_bits_) | (static_cast<uint16_t>(byte) << num_saved_bits_);
37 if (total_bits >= 8) {
38 uint8_t new_byte = static_cast<uint8_t>(new_value);
39 on_byte(new_byte);
40 curr_packet_->AddOctets1(new_byte);
41 if (curr_packet_->size() >= mtu_) {
42 iterator_ = std::move(curr_packet_);
43 curr_packet_ = std::make_unique<RawBuilder>(mtu_);
44 }
45 total_bits -= 8;
46 new_value = new_value >> 8;
47 }
48 num_saved_bits_ = total_bits;
49 uint8_t mask = static_cast<uint8_t>(0xff) >> (8 - num_saved_bits_);
50 saved_bits_ = static_cast<uint8_t>(new_value) & mask;
51 }
52
finalize()53 void FragmentingInserter::finalize() {
54 if (curr_packet_->size() != 0) {
55 iterator_ = std::move(curr_packet_);
56 }
57 curr_packet_.reset();
58 }
59
60 } // namespace packet
61 } // namespace bluetooth
62