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/packet_view.h"
18
19 #include <algorithm>
20
21 #include "os/log.h"
22
23 namespace bluetooth {
24 namespace packet {
25
26 template <bool little_endian>
PacketView(const std::forward_list<class View> fragments)27 PacketView<little_endian>::PacketView(const std::forward_list<class View> fragments)
28 : fragments_(fragments), length_(0) {
29 for (auto fragment : fragments_) {
30 length_ += fragment.size();
31 }
32 }
33
34 template <bool little_endian>
PacketView(std::shared_ptr<std::vector<uint8_t>> packet)35 PacketView<little_endian>::PacketView(std::shared_ptr<std::vector<uint8_t>> packet)
36 : fragments_({View(packet, 0, packet->size())}), length_(packet->size()) {}
37
38 template <bool little_endian>
begin() const39 Iterator<little_endian> PacketView<little_endian>::begin() const {
40 return Iterator<little_endian>(this->fragments_, 0);
41 }
42
43 template <bool little_endian>
end() const44 Iterator<little_endian> PacketView<little_endian>::end() const {
45 return Iterator<little_endian>(this->fragments_, size());
46 }
47
48 template <bool little_endian>
operator [](size_t index) const49 uint8_t PacketView<little_endian>::operator[](size_t index) const {
50 return at(index);
51 }
52
53 template <bool little_endian>
at(size_t index) const54 uint8_t PacketView<little_endian>::at(size_t index) const {
55 ASSERT_LOG(index < length_, "Index %zu out of bounds", index);
56 for (const auto& fragment : fragments_) {
57 if (index < fragment.size()) {
58 return fragment[index];
59 }
60 index -= fragment.size();
61 }
62 ASSERT_LOG(false, "Out of fragments searching for index %zu", index);
63 return 0;
64 }
65
66 template <bool little_endian>
size() const67 size_t PacketView<little_endian>::size() const {
68 return length_;
69 }
70
71 template <bool little_endian>
GetSubviewList(size_t begin,size_t end) const72 std::forward_list<View> PacketView<little_endian>::GetSubviewList(size_t begin, size_t end) const {
73 ASSERT(begin <= end);
74 ASSERT(end <= length_);
75
76 std::forward_list<View> view_list;
77 std::forward_list<View>::iterator it = view_list.before_begin();
78 size_t length = end - begin;
79 for (const auto& fragment : fragments_) {
80 if (begin >= fragment.size()) {
81 begin -= fragment.size();
82 } else {
83 View view(fragment, begin, begin + std::min(length, fragment.size() - begin));
84 length -= view.size();
85 it = view_list.insert_after(it, view);
86 begin = 0;
87 }
88 }
89 return view_list;
90 }
91
92 template <bool little_endian>
GetLittleEndianSubview(size_t begin,size_t end) const93 PacketView<true> PacketView<little_endian>::GetLittleEndianSubview(size_t begin, size_t end) const {
94 return PacketView<true>(GetSubviewList(begin, end));
95 }
96
97 template <bool little_endian>
GetBigEndianSubview(size_t begin,size_t end) const98 PacketView<false> PacketView<little_endian>::GetBigEndianSubview(size_t begin, size_t end) const {
99 return PacketView<false>(GetSubviewList(begin, end));
100 }
101
102 template <bool little_endian>
Append(PacketView to_add)103 void PacketView<little_endian>::Append(PacketView to_add) {
104 auto insertion_point = fragments_.begin();
105 size_t remaining_length = length_;
106 while (remaining_length > 0) {
107 remaining_length -= insertion_point->size();
108 if (remaining_length > 0) {
109 insertion_point++;
110 }
111 }
112 ASSERT(insertion_point != fragments_.end());
113 for (const auto& fragment : to_add.fragments_) {
114 fragments_.insert_after(insertion_point, fragment);
115 insertion_point++;
116 }
117 length_ += to_add.length_;
118 }
119
120 // Explicit instantiations for both types of PacketViews.
121 template class PacketView<true>;
122 template class PacketView<false>;
123 } // namespace packet
124 } // namespace bluetooth
125