git.sesse.net Git - cubemap/blob - server.cpp

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <assert.h>
   5 #include <arpa/inet.h>
   6 #include <curl/curl.h>
   7 #include <sys/socket.h>
   8 #include <pthread.h>
   9 #include <sys/types.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/epoll.h>
  12 #include <errno.h>
  13 #include <vector>
  14 #include <string>
  15 #include <map>
  16
  17 #include "metacube.h"
  18 #include "server.h"
  19 #include "mutexlock.h"
  20
  21 using namespace std;
  22
  23 Server::Server()
  24 {
  25         pthread_mutex_init(&mutex, NULL);
  26
  27         epoll_fd = epoll_create(1024);  // Size argument is ignored.
  28         if (epoll_fd == -1) {
  29                 perror("epoll_fd");
  30                 exit(1);
  31         }
  32 }
  33
  34 void Server::run()
  35 {
  36         pthread_t thread;
  37         pthread_create(&thread, NULL, Server::do_work_thunk, this);
  38 }
  39
  40 void *Server::do_work_thunk(void *arg)
  41 {
  42         Server *server = static_cast<Server *>(arg);
  43         server->do_work();
  44         return NULL;
  45 }
  46
  47 void Server::do_work()
  48 {
  49         for ( ;; ) {
  50                 int nfds = epoll_wait(epoll_fd, events, EPOLL_MAX_EVENTS, EPOLL_TIMEOUT_MS);
  51
  52                 MutexLock lock(&mutex);  // We release the mutex between iterations.
  53                 if (nfds == -1) {
  54                         perror("epoll_wait");
  55                         exit(1);
  56                 }
  57
  58                 for (int i = 0; i < nfds; ++i) {
  59                         int fd = events[i].data.fd;
  60                         assert(clients.count(fd) != 0);
  61                         Client *client = &clients[fd];
  62
  63                         if (events[i].events & (EPOLLERR | EPOLLRDHUP | EPOLLHUP)) {
  64                                 close_client(client);
  65                                 continue;
  66                         }
  67
  68                         process_client(client);
  69                 }
  70         }
  71 }
  72
  73 void Server::add_client(int sock)
  74 {
  75         MutexLock lock(&mutex);
  76         Client new_client;
  77         new_client.sock = sock;
  78         new_client.client_request.reserve(1024);
  79         new_client.state = Client::READING_REQUEST;
  80         new_client.header_bytes_sent = 0;
  81         new_client.bytes_sent = 0;
  82
  83         clients.insert(make_pair(sock, new_client));
  84
  85         // Start listening on data from this socket.
  86         epoll_event ev;
  87         ev.events = EPOLLIN | EPOLLRDHUP;
  88         ev.data.fd = sock;
  89         if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) == -1) {
  90                 perror("epoll_ctl(EPOLL_CTL_ADD)");
  91                 exit(1);
  92         }
  93 }
  94
  95 void Server::add_stream(const string &stream_id)
  96 {
  97         MutexLock lock(&mutex);
  98         streams.insert(make_pair(stream_id, Stream()));
  99 }
 100
 101 void Server::set_header(const string &stream_id, const string &header)
 102 {
 103         MutexLock lock(&mutex);
 104         assert(streams.count(stream_id) != 0);
 105         streams[stream_id].header = header;
 106 }
 107
 108 void Server::add_data(const string &stream_id, const char *data, size_t bytes)
 109 {
 110         if (bytes == 0) {
 111                 return;
 112         }
 113
 114         MutexLock lock(&mutex);
 115         assert(streams.count(stream_id) != 0);
 116         Stream *stream = &streams[stream_id];
 117         size_t pos = stream->data_size % BACKLOG_SIZE;
 118         stream->data_size += bytes;
 119
 120         if (pos + bytes > BACKLOG_SIZE) {
 121                 size_t to_copy = BACKLOG_SIZE - pos;
 122                 memcpy(stream->data + pos, data, to_copy);
 123                 data += to_copy;
 124                 bytes -= to_copy;
 125                 pos = 0;
 126         }
 127
 128         memcpy(stream->data + pos, data, bytes);
 129         wake_up_all_clients();
 130 }
 131
 132 void Server::process_client(Client *client)
 133 {
 134         switch (client->state) {
 135         case Client::READING_REQUEST: {
 136                 // Try to read more of the request.
 137                 char buf[1024];
 138                 int ret = read(client->sock, buf, sizeof(buf));
 139                 if (ret == -1) {
 140                         perror("read");
 141                         close_client(client);
 142                         return;
 143                 }
 144                 if (ret == 0) {
 145                         // No data? This really means that we were triggered for something else than
 146                         // POLLIN (which suggests a logic error in epoll).
 147                         fprintf(stderr, "WARNING: fd %d returned unexpectedly 0 bytes!\n", client->sock);
 148                         close_client(client);
 149                         return;
 150                 }
 151
 152                 // Guard against overlong requests gobbling up all of our space.
 153                 if (client->client_request.size() + ret > MAX_CLIENT_REQUEST) {
 154                         fprintf(stderr, "WARNING: fd %d sent overlong request!\n", client->sock);
 155                         close_client(client);
 156                         return;
 157                 }
 158
 159                 // See if we have \r\n\r\n anywhere in the request. We start three bytes
 160                 // before what we just appended, in case we just got the final character.
 161                 size_t existing_req_bytes = client->client_request.size();
 162                 client->client_request.append(string(buf, buf + ret));
 163
 164                 size_t start_at = (existing_req_bytes >= 3 ? existing_req_bytes - 3 : 0);
 165                 const char *ptr = reinterpret_cast<char *>(
 166                         memmem(client->client_request.data() + start_at, client->client_request.size() - start_at,
 167                                "\r\n\r\n", 4));
 168                 if (ptr == NULL) {
 169                         // OK, we don't have the entire header yet. Fine; we'll get it later.
 170                         return;
 171                 }
 172
 173                 if (ptr != client->client_request.data() + client->client_request.size() - 4) {
 174                         fprintf(stderr, "WARNING: fd %d had junk data after request!\n", client->sock);
 175                         close_client(client);
 176                         return;
 177                 }
 178
 179                 parse_request(client);
 180                 break;
 181         }
 182         case Client::SENDING_HEADER: {
 183                 int ret = write(client->sock,
 184                                 client->header.data() + client->header_bytes_sent,
 185                                 client->header.size() - client->header_bytes_sent);
 186                 if (ret == -1) {
 187                         perror("write");
 188                         close_client(client);
 189                         return;
 190                 }
 191
 192                 client->header_bytes_sent += ret;
 193                 assert(client->header_bytes_sent <= client->header.size());
 194
 195                 if (client->header_bytes_sent < client->header.size()) {
 196                         // We haven't sent all yet. Fine; we'll do that later.
 197                         return;
 198                 }
 199
 200                 // We're done sending the header! Clear the entire header to release some memory.
 201                 client->header.clear();
 202
 203                 // Start sending from the end. In other words, we won't send any of the backlog,
 204                 // but we'll start sending immediately as we get data.
 205                 client->state = Client::SENDING_DATA;
 206                 client->bytes_sent = streams[client->stream_id].data_size;
 207                 break;
 208         }
 209         case Client::SENDING_DATA: {
 210                 // See if there's some data we've lost. Ideally, we should drop to a block boundary,
 211                 // but resync will be the mux's problem.
 212                 const Stream &stream = streams[client->stream_id];
 213                 size_t bytes_to_send = stream.data_size - client->bytes_sent;
 214                 if (bytes_to_send > BACKLOG_SIZE) {
 215                         fprintf(stderr, "WARNING: fd %d lost %lld bytes, maybe too slow connection\n",
 216                                 client->sock,
 217                                 (long long int)(bytes_to_send - BACKLOG_SIZE));
 218                         client->bytes_sent = streams[client->stream_id].data_size - BACKLOG_SIZE;
 219                         bytes_to_send = BACKLOG_SIZE;
 220                 }
 221
 222                 // See if we need to split across the circular buffer.
 223                 int ret;
 224                 if ((client->bytes_sent % BACKLOG_SIZE) + bytes_to_send > BACKLOG_SIZE) {
 225                         // TODO: writev
 226                         assert(false);
 227                 } else {
 228                         ret = write(client->sock,
 229                                     stream.data + (client->bytes_sent % BACKLOG_SIZE),
 230                                     bytes_to_send);
 231                 }
 232                 if (ret == -1) {
 233                         perror("write/writev");
 234                         close_client(client);
 235                         return;
 236                 }
 237                 client->bytes_sent += ret;
 238
 239                 if (client->bytes_sent == stream.data_size) {
 240                         // We don't have any more data for this client, so put it to sleep.
 241                         put_client_to_sleep(client);
 242                 }
 243                 break;
 244         }
 245         default:
 246                 // TODO
 247                 assert(false);
 248         }
 249 }
 250
 251 void Server::parse_request(Client *client)
 252 {
 253         // TODO: Actually parse the request. :-)
 254         client->stream_id = "stream";
 255
 256         // Construct the header.
 257         client->header = "HTTP/1.0 200 OK\r\nContent-type: todo/fixme\r\n\r\n" +
 258                 streams[client->stream_id].header;
 259
 260         // Switch states.
 261         client->state = Client::SENDING_HEADER;
 262
 263         epoll_event ev;
 264         ev.events = EPOLLOUT | EPOLLRDHUP;
 265         ev.data.fd = client->sock;
 266
 267         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 268                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 269                 exit(1);
 270         }
 271 }
 272
 273 void Server::close_client(Client *client)
 274 {
 275         if (epoll_ctl(epoll_fd, EPOLL_CTL_DEL, client->sock, NULL) == -1) {
 276                 perror("epoll_ctl(EPOLL_CTL_DEL)");
 277                 exit(1);
 278         }
 279
 280         // Bye-bye!
 281         close(client->sock);
 282         clients.erase(client->sock);
 283 }
 284
 285 void Server::put_client_to_sleep(Client *client)
 286 {
 287         epoll_event ev;
 288         ev.events = EPOLLRDHUP;
 289         ev.data.fd = client->sock;
 290
 291         if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, client->sock, &ev) == -1) {
 292                 perror("epoll_ctl(EPOLL_CTL_MOD)");
 293                 exit(1);
 294         }
 295
 296         sleeping_clients.push_back(client->sock);
 297 }
 298
 299 void Server::wake_up_all_clients()
 300 {
 301         for (unsigned i = 0; i < sleeping_clients.size(); ++i) {
 302                 epoll_event ev;
 303                 ev.events = EPOLLOUT | EPOLLRDHUP;
 304                 ev.data.fd = sleeping_clients[i];
 305                 if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, sleeping_clients[i], &ev) == -1) {
 306                         perror("epoll_ctl(EPOLL_CTL_MOD)");
 307                         exit(1);
 308                 }
 309         }
 310         sleeping_clients.clear();
 311 }