1 /*
2  * Copyright 2018 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 "phy_layer.h"
18 
19 #include <sstream>
20 
21 namespace rootcanal {
22 
PhyLayer(Identifier id,Phy::Type type)23 PhyLayer::PhyLayer(Identifier id, Phy::Type type) : id(id), type(type) {}
24 
Register(std::shared_ptr<PhyDevice> device)25 void PhyLayer::Register(std::shared_ptr<PhyDevice> device) {
26   device->Register(this);
27   phy_devices_.push_back(device);
28 }
29 
Unregister(PhyDevice::Identifier id)30 void PhyLayer::Unregister(PhyDevice::Identifier id) {
31   for (auto& device : phy_devices_) {
32     if (device->id == id) {
33       device->Unregister(this);
34       phy_devices_.remove(device);
35       return;
36     }
37   }
38 }
39 
UnregisterAll()40 void PhyLayer::UnregisterAll() {
41   for (auto& device : phy_devices_) {
42     device->Unregister(this);
43   }
44   phy_devices_.clear();
45 }
46 
ComputeRssi(PhyDevice::Identifier,PhyDevice::Identifier,int8_t)47 int8_t PhyLayer::ComputeRssi(PhyDevice::Identifier /*sender_id*/,
48                              PhyDevice::Identifier /*receiver_id*/, int8_t /*tx_power*/) {
49   // Perform no RSSI computation by default.
50   // Clients overriding this function should use the TX power and
51   // positional information to derive correct device-to-device RSSI.
52   static uint8_t rssi = 0;
53   rssi = (rssi + 5) % 128;
54   return static_cast<int8_t>(-rssi);
55 }
56 
Send(std::vector<uint8_t> const & packet,int8_t tx_power,PhyDevice::Identifier sender_id)57 void PhyLayer::Send(std::vector<uint8_t> const& packet, int8_t tx_power,
58                     PhyDevice::Identifier sender_id) {
59   for (const auto& device : phy_devices_) {
60     // Do not send the packet back to the sender.
61     if (sender_id != device->id) {
62       device->Receive(packet, type, ComputeRssi(sender_id, device->id, tx_power));
63     }
64   }
65 }
66 
Tick()67 void PhyLayer::Tick() {
68   for (auto& device : phy_devices_) {
69     device->Tick();
70   }
71 }
72 
ToString() const73 std::string PhyLayer::ToString() const {
74   std::stringstream factory;
75   switch (type) {
76     case Phy::Type::LOW_ENERGY:
77       factory << "LOW_ENERGY: ";
78       break;
79     case Phy::Type::BR_EDR:
80       factory << "BR_EDR: ";
81       break;
82     default:
83       factory << "Unknown: ";
84   }
85   for (auto& device : phy_devices_) {
86     factory << device->id;
87     factory << ",";
88   }
89 
90   return factory.str();
91 }
92 
93 }  // namespace rootcanal
94