xref: /aosp_15_r20/external/ot-br-posix/third_party/Simple-web-server/repo/http_examples.cpp (revision 4a64e381480ef79f0532b2421e44e6ee336b8e0d)
1 #include "client_http.hpp"
2 #include "server_http.hpp"
3 #include <future>
4 
5 // Added for the json-example
6 #define BOOST_SPIRIT_THREADSAFE
7 #include <boost/property_tree/json_parser.hpp>
8 #include <boost/property_tree/ptree.hpp>
9 
10 // Added for the default_resource example
11 #include <algorithm>
12 #include <boost/filesystem.hpp>
13 #include <fstream>
14 #include <vector>
15 #ifdef HAVE_OPENSSL
16 #include "crypto.hpp"
17 #endif
18 
19 using namespace std;
20 // Added for the json-example:
21 using namespace boost::property_tree;
22 
23 using HttpServer = SimpleWeb::Server<SimpleWeb::HTTP>;
24 using HttpClient = SimpleWeb::Client<SimpleWeb::HTTP>;
25 
main()26 int main() {
27   // HTTP-server at port 8080 using 1 thread
28   // Unless you do more heavy non-threaded processing in the resources,
29   // 1 thread is usually faster than several threads
30   HttpServer server;
31   server.config.port = 8080;
32 
33   // Add resources using path-regex and method-string, and an anonymous function
34   // POST-example for the path /string, responds the posted string
35   server.resource["^/string$"]["POST"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
36     // Retrieve string:
37     auto content = request->content.string();
38     // request->content.string() is a convenience function for:
39     // stringstream ss;
40     // ss << request->content.rdbuf();
41     // auto content=ss.str();
42 
43     *response << "HTTP/1.1 200 OK\r\nContent-Length: " << content.length() << "\r\n\r\n"
44               << content;
45 
46 
47     // Alternatively, use one of the convenience functions, for instance:
48     // response->write(content);
49   };
50 
51   // POST-example for the path /json, responds firstName+" "+lastName from the posted json
52   // Responds with an appropriate error message if the posted json is not valid, or if firstName or lastName is missing
53   // Example posted json:
54   // {
55   //   "firstName": "John",
56   //   "lastName": "Smith",
57   //   "age": 25
58   // }
59   server.resource["^/json$"]["POST"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
60     try {
61       ptree pt;
62       read_json(request->content, pt);
63 
64       auto name = pt.get<string>("firstName") + " " + pt.get<string>("lastName");
65 
66       *response << "HTTP/1.1 200 OK\r\n"
67                 << "Content-Length: " << name.length() << "\r\n\r\n"
68                 << name;
69     }
70     catch(const exception &e) {
71       *response << "HTTP/1.1 400 Bad Request\r\nContent-Length: " << strlen(e.what()) << "\r\n\r\n"
72                 << e.what();
73     }
74 
75 
76     // Alternatively, using a convenience function:
77     // try {
78     //     ptree pt;
79     //     read_json(request->content, pt);
80 
81     //     auto name=pt.get<string>("firstName")+" "+pt.get<string>("lastName");
82     //     response->write(name);
83     // }
84     // catch(const exception &e) {
85     //     response->write(SimpleWeb::StatusCode::client_error_bad_request, e.what());
86     // }
87   };
88 
89   // GET-example for the path /info
90   // Responds with request-information
91   server.resource["^/info$"]["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
92     stringstream stream;
93     stream << "<h1>Request from " << request->remote_endpoint().address().to_string() << ":" << request->remote_endpoint().port() << "</h1>";
94 
95     stream << request->method << " " << request->path << " HTTP/" << request->http_version;
96 
97     stream << "<h2>Query Fields</h2>";
98     auto query_fields = request->parse_query_string();
99     for(auto &field : query_fields)
100       stream << field.first << ": " << field.second << "<br>";
101 
102     stream << "<h2>Header Fields</h2>";
103     for(auto &field : request->header)
104       stream << field.first << ": " << field.second << "<br>";
105 
106     response->write(stream);
107   };
108 
109   // GET-example for the path /match/[number], responds with the matched string in path (number)
110   // For instance a request GET /match/123 will receive: 123
111   server.resource["^/match/([0-9]+)$"]["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
112     response->write(request->path_match[1].str());
113   };
114 
115   // GET-example simulating heavy work in a separate thread
116   server.resource["^/work$"]["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> /*request*/) {
117     thread work_thread([response] {
118       this_thread::sleep_for(chrono::seconds(5));
119       response->write("Work done");
120     });
121     work_thread.detach();
122   };
123 
124   // Default GET-example. If no other matches, this anonymous function will be called.
125   // Will respond with content in the web/-directory, and its subdirectories.
126   // Default file: index.html
127   // Can for instance be used to retrieve an HTML 5 client that uses REST-resources on this server
128   server.default_resource["GET"] = [](shared_ptr<HttpServer::Response> response, shared_ptr<HttpServer::Request> request) {
129     try {
130       auto web_root_path = boost::filesystem::canonical("web");
131       auto path = boost::filesystem::canonical(web_root_path / request->path);
132       // Check if path is within web_root_path
133       if(distance(web_root_path.begin(), web_root_path.end()) > distance(path.begin(), path.end()) ||
134          !equal(web_root_path.begin(), web_root_path.end(), path.begin()))
135         throw invalid_argument("path must be within root path");
136       if(boost::filesystem::is_directory(path))
137         path /= "index.html";
138 
139       SimpleWeb::CaseInsensitiveMultimap header;
140 
141       // Uncomment the following line to enable Cache-Control
142       // header.emplace("Cache-Control", "max-age=86400");
143 
144 #ifdef HAVE_OPENSSL
145 //    Uncomment the following lines to enable ETag
146 //    {
147 //      ifstream ifs(path.string(), ifstream::in | ios::binary);
148 //      if(ifs) {
149 //        auto hash = SimpleWeb::Crypto::to_hex_string(SimpleWeb::Crypto::md5(ifs));
150 //        header.emplace("ETag", "\"" + hash + "\"");
151 //        auto it = request->header.find("If-None-Match");
152 //        if(it != request->header.end()) {
153 //          if(!it->second.empty() && it->second.compare(1, hash.size(), hash) == 0) {
154 //            response->write(SimpleWeb::StatusCode::redirection_not_modified, header);
155 //            return;
156 //          }
157 //        }
158 //      }
159 //      else
160 //        throw invalid_argument("could not read file");
161 //    }
162 #endif
163 
164       auto ifs = make_shared<ifstream>();
165       ifs->open(path.string(), ifstream::in | ios::binary | ios::ate);
166 
167       if(*ifs) {
168         auto length = ifs->tellg();
169         ifs->seekg(0, ios::beg);
170 
171         header.emplace("Content-Length", to_string(length));
172         response->write(header);
173 
174         // Trick to define a recursive function within this scope (for example purposes)
175         class FileServer {
176         public:
177           static void read_and_send(const shared_ptr<HttpServer::Response> &response, const shared_ptr<ifstream> &ifs) {
178             // Read and send 128 KB at a time
179             static vector<char> buffer(131072); // Safe when server is running on one thread
180             streamsize read_length;
181             if((read_length = ifs->read(&buffer[0], static_cast<streamsize>(buffer.size())).gcount()) > 0) {
182               response->write(&buffer[0], read_length);
183               if(read_length == static_cast<streamsize>(buffer.size())) {
184                 response->send([response, ifs](const SimpleWeb::error_code &ec) {
185                   if(!ec)
186                     read_and_send(response, ifs);
187                   else
188                     cerr << "Connection interrupted" << endl;
189                 });
190               }
191             }
192           }
193         };
194         FileServer::read_and_send(response, ifs);
195       }
196       else
197         throw invalid_argument("could not read file");
198     }
199     catch(const exception &e) {
200       response->write(SimpleWeb::StatusCode::client_error_bad_request, "Could not open path " + request->path + ": " + e.what());
201     }
202   };
203 
204   server.on_error = [](shared_ptr<HttpServer::Request> /*request*/, const SimpleWeb::error_code & /*ec*/) {
205     // Handle errors here
206     // Note that connection timeouts will also call this handle with ec set to SimpleWeb::errc::operation_canceled
207   };
208 
209   // Start server and receive assigned port when server is listening for requests
210   promise<unsigned short> server_port;
211   thread server_thread([&server, &server_port]() {
212     // Start server
213     server.start([&server_port](unsigned short port) {
214       server_port.set_value(port);
215     });
216   });
217   cout << "Server listening on port " << server_port.get_future().get() << endl
218        << endl;
219 
220   // Client examples
221   string json_string = "{\"firstName\": \"John\",\"lastName\": \"Smith\",\"age\": 25}";
222 
223   // Synchronous request examples
224   {
225     HttpClient client("localhost:8080");
226     try {
227       cout << "Example GET request to http://localhost:8080/match/123" << endl;
228       auto r1 = client.request("GET", "/match/123");
229       cout << "Response content: " << r1->content.rdbuf() << endl // Alternatively, use the convenience function r1->content.string()
230            << endl;
231 
232       cout << "Example POST request to http://localhost:8080/string" << endl;
233       auto r2 = client.request("POST", "/string", json_string);
234       cout << "Response content: " << r2->content.rdbuf() << endl
235            << endl;
236     }
237     catch(const SimpleWeb::system_error &e) {
238       cerr << "Client request error: " << e.what() << endl;
239     }
240   }
241 
242   // Asynchronous request example
243   {
244     HttpClient client("localhost:8080");
245     cout << "Example POST request to http://localhost:8080/json" << endl;
246     client.request("POST", "/json", json_string, [](shared_ptr<HttpClient::Response> response, const SimpleWeb::error_code &ec) {
247       if(!ec)
248         cout << "Response content: " << response->content.rdbuf() << endl;
249     });
250     client.io_service->run();
251   }
252 
253   server_thread.join();
254 }
255