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

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <netdb.h>
   4 #include <netinet/in.h>
   5 #include <poll.h>
   6 #include <stdint.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <sys/ioctl.h>
  10 #include <sys/socket.h>
  11 #include <sys/time.h>
  12 #include <time.h>
  13 #include <unistd.h>
  14 #include <math.h>
  15 #include <map>
  16 #include <string>
  17 #include <utility>
  18 #include <vector>
  19
  20 #include "httpinput.h"
  21 #include "log.h"
  22 #include "metacube2.h"
  23 #include "parse.h"
  24 #include "serverpool.h"
  25 #include "state.pb.h"
  26 #include "stream.h"
  27 #include "timespec.h"
  28 #include "util.h"
  29 #include "version.h"
  30
  31 using namespace std;
  32
  33 namespace {
  34
  35 string host_header(const string &host, const string &port)
  36 {
  37         if (port == "http" || atoi(port.c_str()) == 80) {
  38                 return host;
  39         } else {
  40                 return host + ":" + port;
  41         }
  42 }
  43
  44 }  // namespace
  45
  46 extern ServerPool *servers;
  47
  48 HTTPInput::HTTPInput(const string &url, Input::Encoding encoding)
  49         : state(NOT_CONNECTED),
  50           url(url),
  51           encoding(encoding)
  52 {
  53         stats.url = url;
  54         stats.bytes_received = 0;
  55         stats.data_bytes_received = 0;
  56         stats.metadata_bytes_received = 0;
  57         stats.connect_time = -1;
  58         stats.latency_sec = HUGE_VAL;
  59 }
  60
  61 HTTPInput::HTTPInput(const InputProto &serialized)
  62         : state(State(serialized.state())),
  63           url(serialized.url()),
  64           encoding(serialized.is_metacube_encoded() ?
  65                    Input::INPUT_ENCODING_METACUBE :
  66                    Input::INPUT_ENCODING_RAW),
  67           request(serialized.request()),
  68           request_bytes_sent(serialized.request_bytes_sent()),
  69           response(serialized.response()),
  70           http_header(serialized.http_header()),
  71           stream_header(serialized.stream_header()),
  72           has_metacube_header(serialized.has_metacube_header()),
  73           sock(serialized.sock())
  74 {
  75         pending_data.resize(serialized.pending_data().size());
  76         memcpy(&pending_data[0], serialized.pending_data().data(), serialized.pending_data().size());
  77
  78         string protocol, user;
  79         parse_url(url, &protocol, &user, &host, &port, &path);  // Don't care if it fails.
  80
  81         stats.url = url;
  82         stats.bytes_received = serialized.bytes_received();
  83         stats.data_bytes_received = serialized.data_bytes_received();
  84         stats.metadata_bytes_received = serialized.metadata_bytes_received();
  85         if (serialized.has_connect_time()) {
  86                 stats.connect_time = serialized.connect_time();
  87         } else {
  88                 stats.connect_time = time(nullptr);
  89         }
  90         if (serialized.has_latency_sec()) {
  91                 stats.latency_sec = serialized.latency_sec();
  92         } else {
  93                 stats.latency_sec = HUGE_VAL;
  94         }
  95
  96         last_verbose_connection.tv_sec = -3600;
  97         last_verbose_connection.tv_nsec = 0;
  98 }
  99
 100 void HTTPInput::close_socket()
 101 {
 102         if (sock != -1) {
 103                 safe_close(sock);
 104                 sock = -1;
 105         }
 106
 107         lock_guard<mutex> lock(stats_mutex);
 108         stats.connect_time = -1;
 109 }
 110
 111 InputProto HTTPInput::serialize() const
 112 {
 113         InputProto serialized;
 114         serialized.set_state(state);
 115         serialized.set_url(url);
 116         serialized.set_request(request);
 117         serialized.set_request_bytes_sent(request_bytes_sent);
 118         serialized.set_response(response);
 119         serialized.set_http_header(http_header);
 120         serialized.set_stream_header(stream_header);
 121         serialized.set_pending_data(string(pending_data.begin(), pending_data.end()));
 122         serialized.set_has_metacube_header(has_metacube_header);
 123         serialized.set_sock(sock);
 124         serialized.set_bytes_received(stats.bytes_received);
 125         serialized.set_data_bytes_received(stats.data_bytes_received);
 126         if (isfinite(stats.latency_sec)) {
 127                 serialized.set_latency_sec(stats.latency_sec);
 128         }
 129         serialized.set_connect_time(stats.connect_time);
 130         if (encoding == Input::INPUT_ENCODING_METACUBE) {
 131                 serialized.set_is_metacube_encoded(true);
 132         } else {
 133                 assert(encoding == Input::INPUT_ENCODING_RAW);
 134                 serialized.set_is_metacube_encoded(false);
 135         }
 136         return serialized;
 137 }
 138
 139 int HTTPInput::lookup_and_connect(const string &host, const string &port)
 140 {
 141         addrinfo *ai;
 142         int err = getaddrinfo(host.c_str(), port.c_str(), nullptr, &ai);
 143         if (err != 0) {
 144                 if (!suppress_logging) {
 145                         log(WARNING, "[%s] Lookup of '%s' failed (%s).",
 146                                 url.c_str(), host.c_str(), gai_strerror(err));
 147                 }
 148                 return -1;
 149         }
 150
 151         addrinfo *base_ai = ai;
 152
 153         // Connect to everything in turn until we have a socket.
 154         for ( ; ai && !should_stop(); ai = ai->ai_next) {
 155                 int sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
 156                 if (sock == -1) {
 157                         // Could be e.g. EPROTONOSUPPORT. The show must go on.
 158                         continue;
 159                 }
 160
 161                 // Now do a non-blocking connect. This is important because we want to be able to be
 162                 // woken up, even though it's rather cumbersome.
 163
 164                 // Set the socket as nonblocking.
 165                 int one = 1;
 166                 if (ioctl(sock, FIONBIO, &one) == -1) {
 167                         log_perror("ioctl(FIONBIO)");
 168                         safe_close(sock);
 169                         return -1;
 170                 }
 171
 172                 // Do a non-blocking connect.
 173                 do {
 174                         err = connect(sock, ai->ai_addr, ai->ai_addrlen);
 175                 } while (err == -1 && errno == EINTR);
 176
 177                 if (err == -1 && errno != EINPROGRESS) {
 178                         log_perror("connect");
 179                         safe_close(sock);
 180                         continue;
 181                 }
 182
 183                 // Wait for the connect to complete, or an error to happen.
 184                 for ( ;; ) {
 185                         bool complete = wait_for_activity(sock, POLLIN | POLLOUT, nullptr);
 186                         if (should_stop()) {
 187                                 safe_close(sock);
 188                                 return -1;
 189                         }
 190                         if (complete) {
 191                                 break;
 192                         }
 193                 }
 194
 195                 // Check whether it ended in an error or not.
 196                 socklen_t err_size = sizeof(err);
 197                 if (getsockopt(sock, SOL_SOCKET, SO_ERROR, &err, &err_size) == -1) {
 198                         log_perror("getsockopt");
 199                         safe_close(sock);
 200                         continue;
 201                 }
 202
 203                 errno = err;
 204
 205                 if (err == 0) {
 206                         // Successful connect.
 207                         freeaddrinfo(base_ai);
 208                         return sock;
 209                 }
 210
 211                 safe_close(sock);
 212         }
 213
 214         // Give the last one as error.
 215         if (!suppress_logging) {
 216                 log(WARNING, "[%s] Connect to '%s' failed (%s)",
 217                         url.c_str(), host.c_str(), strerror(errno));
 218         }
 219         freeaddrinfo(base_ai);
 220         return -1;
 221 }
 222
 223 bool HTTPInput::parse_response(const string &request)
 224 {
 225         vector<string> lines = split_lines(response);
 226         if (lines.empty()) {
 227                 if (!suppress_logging) {
 228                         log(WARNING, "[%s] Empty HTTP response from input.", url.c_str());
 229                 }
 230                 return false;
 231         }
 232
 233         vector<string> first_line_tokens = split_tokens(lines[0]);
 234         if (first_line_tokens.size() < 2) {
 235                 if (!suppress_logging) {
 236                         log(WARNING, "[%s] Malformed response line '%s' from input.",
 237                                 url.c_str(), lines[0].c_str());
 238                 }
 239                 return false;
 240         }
 241
 242         int response = atoi(first_line_tokens[1].c_str());
 243         if (response != 200) {
 244                 if (!suppress_logging) {
 245                         log(WARNING, "[%s] Non-200 response '%s' from input.",
 246                                 url.c_str(), lines[0].c_str());
 247                 }
 248                 return false;
 249         }
 250
 251         multimap<string, string> parameters = extract_headers(lines, url);
 252
 253         // Remove “Content-encoding: metacube”.
 254         // TODO: Make case-insensitive.
 255         const auto encoding_it = parameters.find("Content-encoding");
 256         if (encoding_it != parameters.end() && encoding_it->second == "metacube") {
 257                 parameters.erase(encoding_it);
 258         }
 259
 260         // Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
 261         // TODO: Make case-insensitive.
 262         // XXX: Use a Via: instead?
 263         if (parameters.count("Server") == 0) {
 264                 parameters.insert(make_pair("Server", SERVER_IDENTIFICATION));
 265         } else {
 266                 for (auto &key_and_value : parameters) {
 267                         if (key_and_value.first != "Server") {
 268                                 continue;
 269                         }
 270                         key_and_value.second = SERVER_IDENTIFICATION " (reflecting: " + key_and_value.second + ")";
 271                 }
 272         }
 273
 274         // Erase “Connection: close”; we'll set it on the sending side if needed.
 275         // TODO: Make case-insensitive.
 276         parameters.erase("Connection");
 277
 278         // Construct the new HTTP header.
 279         http_header = "HTTP/1.0 200 OK\r\n";
 280         for (const auto &key_and_value : parameters) {
 281                 http_header.append(key_and_value.first + ": " + key_and_value.second + "\r\n");
 282         }
 283
 284         for (int stream_index : stream_indices) {
 285                 servers->set_header(stream_index, http_header, stream_header);
 286         }
 287
 288         return true;
 289 }
 290
 291 void HTTPInput::do_work()
 292 {
 293         timespec last_activity;
 294
 295         // TODO: Make the timeout persist across restarts.
 296         if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 297                 int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 298                 assert(err != -1);
 299         }
 300
 301         while (!should_stop()) {
 302                 if (state == SENDING_REQUEST || state == RECEIVING_HEADER || state == RECEIVING_DATA) {
 303                         // Give the socket 30 seconds since last activity before we time out.
 304                         static const int timeout_secs = 30;
 305
 306                         timespec now;
 307                         int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
 308                         assert(err != -1);
 309
 310                         timespec elapsed = clock_diff(last_activity, now);
 311                         if (elapsed.tv_sec >= timeout_secs) {
 312                                 // Timeout!
 313                                 if (!suppress_logging) {
 314                                         log(ERROR, "[%s] Timeout after %d seconds, closing.", url.c_str(), elapsed.tv_sec);
 315                                 }
 316                                 state = CLOSING_SOCKET;
 317                                 continue;
 318                         }
 319
 320                         // Basically calculate (30 - (now - last_activity)) = (30 + (last_activity - now)).
 321                         // Add a second of slack to account for differences between clocks.
 322                         timespec timeout = clock_diff(now, last_activity);
 323                         timeout.tv_sec += timeout_secs + 1;
 324                         assert(timeout.tv_sec > 0 || (timeout.tv_sec >= 0 && timeout.tv_nsec > 0));
 325
 326                         bool activity = wait_for_activity(sock, (state == SENDING_REQUEST) ? POLLOUT : POLLIN, &timeout);
 327                         if (activity) {
 328                                 err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 329                                 assert(err != -1);
 330                         } else {
 331                                 // OK. Most likely, should_stop was set, or we have timed out.
 332                                 continue;
 333                         }
 334                 }
 335
 336                 switch (state) {
 337                 case NOT_CONNECTED:
 338                         request.clear();
 339                         request_bytes_sent = 0;
 340                         response.clear();
 341                         pending_data.clear();
 342                         has_metacube_header = false;
 343                         for (int stream_index : stream_indices) {
 344                                 servers->set_header(stream_index, "", "");
 345                         }
 346
 347                         {
 348                                 string protocol, user;  // Thrown away.
 349                                 if (!parse_url(url, &protocol, &user, &host, &port, &path)) {
 350                                         if (!suppress_logging) {
 351                                                 log(WARNING, "[%s] Failed to parse URL '%s'", url.c_str(), url.c_str());
 352                                         }
 353                                         break;
 354                                 }
 355
 356                                 // Remove the brackets around IPv6 address literals.
 357                                 // TODO: See if we can join this with the code in parse_ip_address(),
 358                                 // or maybe even more it into parse_url().
 359                                 if (!host.empty() && host[0] == '[' && host[host.size() - 1] == ']') {
 360                                         host = host.substr(1, host.size() - 2);
 361                                 }
 362                         }
 363
 364                         if (suppress_logging) {
 365                                 // See if there's more than one minute since last time we made a connection
 366                                 // with logging enabled. If so, turn it on again.
 367                                 timespec now;
 368                                 int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &now);
 369                                 assert(err != -1);
 370
 371                                 double elapsed = now.tv_sec - last_verbose_connection.tv_sec +
 372                                         1e-9 * (now.tv_nsec - last_verbose_connection.tv_nsec);
 373                                 if (elapsed > 60.0) {
 374                                         suppress_logging = false;
 375                                 }
 376                         }
 377                         if (!suppress_logging) {
 378                                 int err = clock_gettime(CLOCK_MONOTONIC_COARSE, &last_verbose_connection);
 379                                 assert(err != -1);
 380                         }
 381                         ++num_connection_attempts;
 382                         sock = lookup_and_connect(host, port);
 383                         if (sock != -1) {
 384                                 // Yay, successful connect. Try to set it as nonblocking.
 385                                 int one = 1;
 386                                 if (ioctl(sock, FIONBIO, &one) == -1) {
 387                                         log_perror("ioctl(FIONBIO)");
 388                                         state = CLOSING_SOCKET;
 389                                 } else {
 390                                         state = SENDING_REQUEST;
 391                                         request = "GET " + path + " HTTP/1.0\r\nHost: " + host_header(host, port) + "\r\nUser-Agent: cubemap\r\n\r\n";
 392                                         request_bytes_sent = 0;
 393                                 }
 394
 395                                 lock_guard<mutex> lock(stats_mutex);
 396                                 stats.connect_time = time(nullptr);
 397                                 clock_gettime(CLOCK_MONOTONIC_COARSE, &last_activity);
 398                         }
 399                         break;
 400                 case SENDING_REQUEST: {
 401                         size_t to_send = request.size() - request_bytes_sent;
 402                         int ret;
 403
 404                         do {
 405                                 ret = write(sock, request.data() + request_bytes_sent, to_send);
 406                         } while (ret == -1 && errno == EINTR);
 407
 408                         if (ret == -1) {
 409                                 log_perror("write");
 410                                 state = CLOSING_SOCKET;
 411                                 continue;
 412                         }
 413
 414                         assert(ret >= 0);
 415                         request_bytes_sent += ret;
 416
 417                         if (request_bytes_sent == request.size()) {
 418                                 state = RECEIVING_HEADER;
 419                         }
 420                         break;
 421                 }
 422                 case RECEIVING_HEADER: {
 423                         char buf[4096];
 424                         int ret;
 425
 426                         do {
 427                                 ret = read(sock, buf, sizeof(buf));
 428                         } while (ret == -1 && errno == EINTR);
 429
 430                         if (ret == -1) {
 431                                 log_perror("read");
 432                                 state = CLOSING_SOCKET;
 433                                 continue;
 434                         }
 435
 436                         if (ret == 0) {
 437                                 // This really shouldn't happen...
 438                                 if (!suppress_logging) {
 439                                         log(ERROR, "[%s] Socket unexpectedly closed while reading header",
 440                                                    url.c_str());
 441                                 }
 442                                 state = CLOSING_SOCKET;
 443                                 continue;
 444                         }
 445
 446                         RequestParseStatus status = wait_for_double_newline(&response, buf, ret);
 447
 448                         if (status == RP_OUT_OF_SPACE) {
 449                                 if (!suppress_logging) {
 450                                         log(WARNING, "[%s] Server sent overlong HTTP response!", url.c_str());
 451                                 }
 452                                 state = CLOSING_SOCKET;
 453                                 continue;
 454                         } else if (status == RP_NOT_FINISHED_YET) {
 455                                 continue;
 456                         }
 457
 458                         // OK, so we're fine, but there might be some of the actual data after the response.
 459                         // We'll need to deal with that separately.
 460                         string extra_data;
 461                         if (status == RP_EXTRA_DATA) {
 462                                 char *ptr = static_cast<char *>(
 463                                         memmem(response.data(), response.size(), "\r\n\r\n", 4));
 464                                 assert(ptr != nullptr);
 465                                 extra_data = string(ptr + 4, &response[0] + response.size());
 466                                 response.resize(ptr - response.data());
 467                         }
 468
 469                         if (!parse_response(response)) {
 470                                 state = CLOSING_SOCKET;
 471                                 continue;
 472                         }
 473
 474                         if (!extra_data.empty()) {
 475                                 process_data(&extra_data[0], extra_data.size());
 476                         }
 477
 478                         if (!suppress_logging) {
 479                                 if (encoding == Input::INPUT_ENCODING_RAW) {
 480                                         log(INFO, "[%s] Connected to '%s', receiving raw data.",
 481                                                    url.c_str(), url.c_str());
 482                                 } else {
 483                                         assert(encoding == Input::INPUT_ENCODING_METACUBE);
 484                                         log(INFO, "[%s] Connected to '%s', receiving data.",
 485                                                    url.c_str(), url.c_str());
 486                                 }
 487                         }
 488                         state = RECEIVING_DATA;
 489                         break;
 490                 }
 491                 case RECEIVING_DATA: {
 492                         char buf[4096];
 493                         int ret;
 494
 495                         do {
 496                                 ret = read(sock, buf, sizeof(buf));
 497                         } while (ret == -1 && errno == EINTR);
 498
 499                         if (ret == -1) {
 500                                 log_perror("read");
 501                                 state = CLOSING_SOCKET;
 502                                 continue;
 503                         }
 504
 505                         if (ret == 0) {
 506                                 // This really shouldn't happen...
 507                                 if (!suppress_logging) {
 508                                         log(ERROR, "[%s] Socket unexpectedly closed while reading data",
 509                                                    url.c_str());
 510                                 }
 511                                 state = CLOSING_SOCKET;
 512                                 continue;
 513                         }
 514
 515                         num_connection_attempts = 0;  // Reset, since we have a successful read.
 516                         if (suppress_logging) {
 517                                 // This was suppressed earlier, so print it out now.
 518                                 if (encoding == Input::INPUT_ENCODING_RAW) {
 519                                         log(INFO, "[%s] Connected to '%s', receiving raw data.",
 520                                                    url.c_str(), url.c_str());
 521                                 } else {
 522                                         assert(encoding == Input::INPUT_ENCODING_METACUBE);
 523                                         log(INFO, "[%s] Connected to '%s', receiving data.",
 524                                                    url.c_str(), url.c_str());
 525                                 }
 526                                 suppress_logging = false;
 527                         }
 528
 529                         process_data(buf, ret);
 530                         break;
 531                 }
 532                 case CLOSING_SOCKET: {
 533                         close_socket();
 534                         state = NOT_CONNECTED;
 535                         break;
 536                 }
 537                 default:
 538                         assert(false);
 539                 }
 540
 541                 // If we are still in NOT_CONNECTED, either something went wrong,
 542                 // or the connection just got closed.
 543                 // The earlier steps have already given the error message, if any.
 544                 if (state == NOT_CONNECTED && !should_stop()) {
 545                         if (!suppress_logging) {
 546                                 log(INFO, "[%s] Waiting 0.2 seconds and restarting...", url.c_str());
 547                         }
 548
 549                         if (num_connection_attempts >= 3 && !suppress_logging) {
 550                                 log(INFO, "[%s] %d failed connection attempts, suppressing logging for one minute.",
 551                                         url.c_str(), num_connection_attempts);
 552                                 suppress_logging = true;
 553                         }
 554                         timespec timeout_ts;
 555                         timeout_ts.tv_sec = 0;
 556                         timeout_ts.tv_nsec = 200000000;
 557                         wait_for_wakeup(&timeout_ts);
 558                 }
 559         }
 560 }
 561
 562 void HTTPInput::process_data(char *ptr, size_t bytes)
 563 {
 564         {
 565                 lock_guard<mutex> lock(stats_mutex);
 566                 stats.bytes_received += bytes;
 567         }
 568
 569         if (encoding == Input::INPUT_ENCODING_RAW) {
 570                 for (int stream_index : stream_indices) {
 571                         servers->add_data(stream_index, ptr, bytes, /*metacube_flags=*/0);
 572                 }
 573                 return;
 574         }
 575
 576         assert(encoding == Input::INPUT_ENCODING_METACUBE);
 577         pending_data.insert(pending_data.end(), ptr, ptr + bytes);
 578
 579         for ( ;; ) {
 580                 // If we don't have enough data (yet) for even the Metacube header, just return.
 581                 if (pending_data.size() < sizeof(metacube2_block_header)) {
 582                         return;
 583                 }
 584
 585                 // Make sure we have the Metacube sync header at the start.
 586                 // We may need to skip over junk data (it _should_ not happen, though).
 587                 if (!has_metacube_header) {
 588                         char *ptr = static_cast<char *>(
 589                                 memmem(pending_data.data(), pending_data.size(),
 590                                        METACUBE2_SYNC, strlen(METACUBE2_SYNC)));
 591                         if (ptr == nullptr) {
 592                                 // OK, so we didn't find the sync marker. We know then that
 593                                 // we do not have the _full_ marker in the buffer, but we
 594                                 // could have N-1 bytes. Drop everything before that,
 595                                 // and then give up.
 596                                 drop_pending_data(pending_data.size() - (strlen(METACUBE2_SYNC) - 1));
 597                                 return;
 598                         } else {
 599                                 // Yay, we found the header. Drop everything (if anything) before it.
 600                                 drop_pending_data(ptr - pending_data.data());
 601                                 has_metacube_header = true;
 602
 603                                 // Re-check that we have the entire header; we could have dropped data.
 604                                 if (pending_data.size() < sizeof(metacube2_block_header)) {
 605                                         return;
 606                                 }
 607                         }
 608                 }
 609
 610                 // Now it's safe to read the header.
 611                 metacube2_block_header hdr;
 612                 memcpy(&hdr, pending_data.data(), sizeof(hdr));
 613                 assert(memcmp(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync)) == 0);
 614                 uint32_t size = ntohl(hdr.size);
 615                 uint16_t flags = ntohs(hdr.flags);
 616                 uint16_t expected_csum = metacube2_compute_crc(&hdr);
 617
 618                 if (expected_csum != ntohs(hdr.csum)) {
 619                         log(WARNING, "[%s] Metacube checksum failed (expected 0x%x, got 0x%x), "
 620                                 "not reading block claiming to be %d bytes (flags=%x).",
 621                                 url.c_str(), expected_csum, ntohs(hdr.csum),
 622                                 size, flags);
 623
 624                         // Drop only the first byte, and let the rest of the code handle resync.
 625                         pending_data.erase(pending_data.begin(), pending_data.begin() + 1);
 626                         has_metacube_header = false;
 627                         continue;
 628                 }
 629                 if (size > 10485760) {
 630                         log(WARNING, "[%s] Metacube block of %d bytes (flags=%x); corrupted header??",
 631                                 url.c_str(), size, flags);
 632                 }
 633
 634                 // See if we have the entire block. If not, wait for more data.
 635                 if (pending_data.size() < sizeof(metacube2_block_header) + size) {
 636                         return;
 637                 }
 638
 639                 // See if this is a metadata block. If so, we don't want to send it on,
 640                 // but rather process it ourselves.
 641                 // TODO: Keep metadata when sending on to other Metacube users.
 642                 if (flags & METACUBE_FLAGS_METADATA) {
 643                         {
 644                                 lock_guard<mutex> lock(stats_mutex);
 645                                 stats.metadata_bytes_received += size;
 646                         }
 647                         process_metacube_metadata_block(hdr, pending_data.data() + sizeof(hdr), size);
 648                 } else {
 649                         // Send this block on to the servers.
 650                         {
 651                                 lock_guard<mutex> lock(stats_mutex);
 652                                 stats.data_bytes_received += size;
 653                         }
 654                         char *inner_data = pending_data.data() + sizeof(metacube2_block_header);
 655                         if (flags & METACUBE_FLAGS_HEADER) {
 656                                 stream_header = string(inner_data, inner_data + size);
 657                                 for (int stream_index : stream_indices) {
 658                                         servers->set_header(stream_index, http_header, stream_header);
 659                                 }
 660                         }
 661                         for (int stream_index : stream_indices) {
 662                                 servers->add_data(stream_index, inner_data, size, flags);
 663                         }
 664                 }
 665
 666                 // Consume the block. This isn't the most efficient way of dealing with things
 667                 // should we have many blocks, but these routines don't need to be too efficient
 668                 // anyway.
 669                 pending_data.erase(pending_data.begin(), pending_data.begin() + sizeof(metacube2_block_header) + size);
 670                 has_metacube_header = false;
 671         }
 672 }
 673
 674 void HTTPInput::drop_pending_data(size_t num_bytes)
 675 {
 676         if (num_bytes == 0) {
 677                 return;
 678         }
 679         log(WARNING, "[%s] Dropping %lld junk bytes; not a Metacube2 stream, or data was dropped from the middle of the stream.",
 680                 url.c_str(), (long long)num_bytes);
 681         assert(pending_data.size() >= num_bytes);
 682         pending_data.erase(pending_data.begin(), pending_data.begin() + num_bytes);
 683 }
 684
 685 void HTTPInput::add_destination(int stream_index)
 686 {
 687         stream_indices.push_back(stream_index);
 688         servers->set_header(stream_index, http_header, stream_header);
 689 }
 690
 691 InputStats HTTPInput::get_stats() const
 692 {
 693         lock_guard<mutex> lock(stats_mutex);
 694         return stats;
 695 }
 696
 697 void HTTPInput::process_metacube_metadata_block(const metacube2_block_header &hdr, const char *payload, uint32_t payload_size)
 698 {
 699         if (payload_size < sizeof(uint64_t)) {
 700                 log(WARNING, "[%s] Undersized Metacube metadata block (%d bytes); corrupted header?",
 701                         url.c_str(), payload_size);
 702                 return;
 703         }
 704
 705         uint64_t type = be64toh(*(const uint64_t *)payload);
 706         if (type != METACUBE_METADATA_TYPE_ENCODER_TIMESTAMP) {
 707                 // Unknown metadata block, ignore.
 708                 return;
 709         }
 710
 711         timespec now;
 712         clock_gettime(CLOCK_REALTIME, &now);
 713
 714         const metacube2_timestamp_packet *pkt = (const metacube2_timestamp_packet *)payload;
 715         if (payload_size != sizeof(*pkt)) {
 716                 log(WARNING, "[%s] Metacube timestamp block of wrong size (%d bytes); ignoring.",
 717                         url.c_str(), payload_size);
 718                 return;
 719         }
 720
 721         double elapsed = now.tv_sec - be64toh(pkt->tv_sec) +
 722                 1e-9 * (now.tv_nsec - long(be64toh(pkt->tv_nsec)));
 723         {
 724                 lock_guard<mutex> lock(stats_mutex);
 725                 stats.latency_sec = elapsed;
 726         }
 727 }