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(size_t mtu,
26 std::back_insert_iterator<std::vector<std::unique_ptr<RawBuilder>>> iterator)
27 : BitInserter(to_construct_bit_inserter_), mtu_(mtu), curr_packet_(std::make_unique<RawBuilder>(mtu)),
28 iterator_(iterator) {}
29
insert_bits(uint8_t byte,size_t num_bits)30 void FragmentingInserter::insert_bits(uint8_t byte, size_t num_bits) {
31 assert(curr_packet_ != nullptr);
32 size_t total_bits = num_bits + num_saved_bits_;
33 uint16_t new_value = static_cast<uint8_t>(saved_bits_) | (static_cast<uint16_t>(byte) << num_saved_bits_);
34 if (total_bits >= 8) {
35 uint8_t new_byte = static_cast<uint8_t>(new_value);
36 on_byte(new_byte);
37 curr_packet_->AddOctets1(new_byte);
38 if (curr_packet_->size() >= mtu_) {
39 iterator_ = std::move(curr_packet_);
40 curr_packet_ = std::make_unique<RawBuilder>(mtu_);
41 }
42 total_bits -= 8;
43 new_value = new_value >> 8;
44 }
45 num_saved_bits_ = total_bits;
46 uint8_t mask = static_cast<uint8_t>(0xff) >> (8 - num_saved_bits_);
47 saved_bits_ = static_cast<uint8_t>(new_value) & mask;
48 }
49
finalize()50 void FragmentingInserter::finalize() {
51 if (curr_packet_->size() != 0) {
52 iterator_ = std::move(curr_packet_);
53 }
54 curr_packet_.reset();
55 }
56
57 } // namespace packet
58 } // namespace bluetooth
59