xref: /openbmc/phosphor-led-manager/manager/json-parser.hpp (revision 158b2c14f54c78d334a21ca3656dc9364f598321)
1 #include "config.h"
2 
3 #include "json-config.hpp"
4 #include "ledlayout.hpp"
5 
6 #include <nlohmann/json.hpp>
7 #include <phosphor-logging/lg2.hpp>
8 #include <sdbusplus/bus.hpp>
9 #include <sdeventplus/event.hpp>
10 
11 #include <filesystem>
12 #include <fstream>
13 #include <iostream>
14 
15 namespace fs = std::filesystem;
16 
17 using Json = nlohmann::json;
18 
19 // Priority for a particular LED needs to stay SAME across all groups
20 // phosphor::led::Layout::Action can only be one of `Blink` and `On`
21 using PriorityMap =
22     std::unordered_map<std::string, phosphor::led::Layout::Action>;
23 
24 /** @brief Parse LED JSON file and output Json object
25  *
26  *  @param[in] path - path of LED JSON file
27  *
28  *  @return const Json - Json object
29  */
30 Json readJson(const fs::path& path)
31 {
32 
33     if (!fs::exists(path) || fs::is_empty(path))
34     {
35         lg2::error("Incorrect File Path or empty file, FILE_PATH = {PATH}",
36                    "PATH", path);
37         throw std::runtime_error("Incorrect File Path or empty file");
38     }
39 
40     try
41     {
42         std::ifstream jsonFile(path);
43         return Json::parse(jsonFile);
44     }
45     catch (const std::exception& e)
46     {
47         lg2::error(
48             "Failed to parse config file, ERROR = {ERROR}, FILE_PATH = {PATH}",
49             "ERROR", e, "PATH", path);
50         throw std::runtime_error("Failed to parse config file");
51     }
52 }
53 
54 /** @brief Returns action enum based on string
55  *
56  *  @param[in] action - action string
57  *
58  *  @return Action - action enum (On/Blink)
59  */
60 phosphor::led::Layout::Action getAction(const std::string& action)
61 {
62     assert(action == "On" || action == "Blink");
63 
64     return action == "Blink" ? phosphor::led::Layout::Action::Blink
65                              : phosphor::led::Layout::Action::On;
66 }
67 
68 /** @brief Validate the Priority of an LED is same across ALL groups
69  *
70  *  @param[in] name - led name member of each group
71  *  @param[in] priority - member priority of each group
72  *  @param[out] priorityMap - std::unordered_map, key:name, value:priority
73  *
74  *  @return
75  */
76 void validatePriority(const std::string& name,
77                       const phosphor::led::Layout::Action& priority,
78                       PriorityMap& priorityMap)
79 {
80 
81     auto iter = priorityMap.find(name);
82     if (iter == priorityMap.end())
83     {
84         priorityMap.emplace(name, priority);
85         return;
86     }
87 
88     if (iter->second != priority)
89     {
90         lg2::error(
91             "Priority of LED is not same across all, Name = {NAME}, Old Priority = {OLD_PRIO}, New Priority = {NEW_PRIO}",
92             "NAME", name, "OLD_PRIO", int(iter->second), "NEW_PRIO",
93             int(priority));
94 
95         throw std::runtime_error(
96             "Priority of at least one LED is not same across groups");
97     }
98 }
99 
100 /** @brief Load JSON config and return led map (JSON version 1)
101  *
102  *  @return phosphor::led::GroupMap
103  */
104 const phosphor::led::GroupMap loadJsonConfigV1(const Json& json)
105 {
106     phosphor::led::GroupMap ledMap{};
107     PriorityMap priorityMap{};
108 
109     // define the default JSON as empty
110     const Json empty{};
111     auto leds = json.value("leds", empty);
112 
113     for (const auto& entry : leds)
114     {
115         fs::path tmpPath(std::string{OBJPATH});
116         tmpPath /= entry.value("group", "");
117         auto objpath = tmpPath.string();
118         auto members = entry.value("members", empty);
119 
120         phosphor::led::ActionSet ledActions{};
121         for (const auto& member : members)
122         {
123             auto name = member.value("Name", "");
124             auto action = getAction(member.value("Action", ""));
125             uint8_t dutyOn = member.value("DutyOn", 50);
126             uint16_t period = member.value("Period", 0);
127 
128             // Since only have Blink/On and default priority is Blink
129             auto priority = getAction(member.value("Priority", "Blink"));
130 
131             // Same LEDs can be part of multiple groups. However, their
132             // priorities across groups need to match.
133             validatePriority(name, priority, priorityMap);
134 
135             phosphor::led::Layout::LedAction ledAction{name, action, dutyOn,
136                                                        period, priority};
137             ledActions.emplace(ledAction);
138         }
139 
140         // Generated an std::unordered_map of LedGroupNames to std::set of LEDs
141         // containing the name and properties.
142         ledMap.emplace(objpath, ledActions);
143     }
144 
145     return ledMap;
146 }
147 
148 /** @brief Load JSON config and return led map
149  *
150  *  @return phosphor::led::GroupMap
151  */
152 const phosphor::led::GroupMap loadJsonConfig(const fs::path& path)
153 {
154     auto json = readJson(path);
155 
156     auto version = json.value("version", 1);
157     switch (version)
158     {
159         case 1:
160             return loadJsonConfigV1(json);
161 
162         default:
163             lg2::error("Unsupported JSON Version: {VERSION}", "VERSION",
164                        version);
165             throw std::runtime_error("Unsupported version");
166     }
167 
168     return phosphor::led::GroupMap{};
169 }
170 
171 /** @brief Get led map from LED groups JSON config
172  *
173  *  @param[in] config - Path to the JSON config.
174  *  @return phosphor::led::GroupMap
175  *
176  *  @note if config is an empty string, daemon will interrogate dbus for
177  *        compatible strings.
178  */
179 const phosphor::led::GroupMap getSystemLedMap(fs::path config)
180 {
181     if (config.empty())
182     {
183         config = phosphor::led::getJsonConfig();
184     }
185 
186     return loadJsonConfig(config);
187 }
188