src/httpfetch.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "socket.h" // for select()
  21 #include "porting.h" // for sleep_ms(), get_sysinfo()
  22 #include "httpfetch.h"
  23 #include <iostream>
  24 #include <sstream>
  25 #include <list>
  26 #include <map>
  27 #include <errno.h>
  28 #include "jthread/jevent.h"
  29 #include "config.h"
  30 #include "exceptions.h"
  31 #include "debug.h"
  32 #include "log.h"
  33 #include "util/container.h"
  34 #include "util/thread.h"
  35 #include "version.h"
  36 #include "main.h"
  37 #include "settings.h"
  38
  39 JMutex g_httpfetch_mutex;
  40 std::map<unsigned long, std::list<HTTPFetchResult> > g_httpfetch_results;
  41
  42 HTTPFetchRequest::HTTPFetchRequest()
  43 {
  44         url = "";
  45         caller = HTTPFETCH_DISCARD;
  46         request_id = 0;
  47         timeout = g_settings->getS32("curl_timeout");
  48         connect_timeout = timeout;
  49
  50         useragent = std::string("Minetest/") + minetest_version_hash + " (" + porting::get_sysinfo() + ")";
  51 }
  52
  53
  54 static void httpfetch_deliver_result(const HTTPFetchResult &fetchresult)
  55 {
  56         unsigned long caller = fetchresult.caller;
  57         if (caller != HTTPFETCH_DISCARD) {
  58                 JMutexAutoLock lock(g_httpfetch_mutex);
  59                 g_httpfetch_results[caller].push_back(fetchresult);
  60         }
  61 }
  62
  63 static void httpfetch_request_clear(unsigned long caller);
  64
  65 unsigned long httpfetch_caller_alloc()
  66 {
  67         JMutexAutoLock lock(g_httpfetch_mutex);
  68
  69         // Check each caller ID except HTTPFETCH_DISCARD
  70         const unsigned long discard = HTTPFETCH_DISCARD;
  71         for (unsigned long caller = discard + 1; caller != discard; ++caller) {
  72                 std::map<unsigned long, std::list<HTTPFetchResult> >::iterator
  73                         it = g_httpfetch_results.find(caller);
  74                 if (it == g_httpfetch_results.end()) {
  75                         verbosestream<<"httpfetch_caller_alloc: allocating "
  76                                         <<caller<<std::endl;
  77                         // Access element to create it
  78                         g_httpfetch_results[caller];
  79                         return caller;
  80                 }
  81         }
  82
  83         assert("httpfetch_caller_alloc: ran out of caller IDs" == 0);
  84         return discard;
  85 }
  86
  87 void httpfetch_caller_free(unsigned long caller)
  88 {
  89         verbosestream<<"httpfetch_caller_free: freeing "
  90                         <<caller<<std::endl;
  91
  92         httpfetch_request_clear(caller);
  93         if (caller != HTTPFETCH_DISCARD) {
  94                 JMutexAutoLock lock(g_httpfetch_mutex);
  95                 g_httpfetch_results.erase(caller);
  96         }
  97 }
  98
  99 bool httpfetch_async_get(unsigned long caller, HTTPFetchResult &fetchresult)
 100 {
 101         JMutexAutoLock lock(g_httpfetch_mutex);
 102
 103         // Check that caller exists
 104         std::map<unsigned long, std::list<HTTPFetchResult> >::iterator
 105                 it = g_httpfetch_results.find(caller);
 106         if (it == g_httpfetch_results.end())
 107                 return false;
 108
 109         // Check that result queue is nonempty
 110         std::list<HTTPFetchResult> &callerresults = it->second;
 111         if (callerresults.empty())
 112                 return false;
 113
 114         // Pop first result
 115         fetchresult = callerresults.front();
 116         callerresults.pop_front();
 117         return true;
 118 }
 119
 120 #if USE_CURL
 121 #include <curl/curl.h>
 122
 123 /*
 124         USE_CURL is on: use cURL based httpfetch implementation
 125 */
 126
 127 static size_t httpfetch_writefunction(
 128                 char *ptr, size_t size, size_t nmemb, void *userdata)
 129 {
 130         std::ostringstream *stream = (std::ostringstream*)userdata;
 131         size_t count = size * nmemb;
 132         stream->write(ptr, count);
 133         return count;
 134 }
 135
 136 static size_t httpfetch_discardfunction(
 137                 char *ptr, size_t size, size_t nmemb, void *userdata)
 138 {
 139         return size * nmemb;
 140 }
 141
 142 class CurlHandlePool
 143 {
 144         std::list<CURL*> handles;
 145
 146 public:
 147         CurlHandlePool() {}
 148         ~CurlHandlePool()
 149         {
 150                 for (std::list<CURL*>::iterator it = handles.begin();
 151                                 it != handles.end(); ++it) {
 152                         curl_easy_cleanup(*it);
 153                 }
 154         }
 155         CURL * alloc()
 156         {
 157                 CURL *curl;
 158                 if (handles.empty()) {
 159                         curl = curl_easy_init();
 160                         if (curl == NULL) {
 161                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 162                         }
 163                 }
 164                 else {
 165                         curl = handles.front();
 166                         handles.pop_front();
 167                 }
 168                 return curl;
 169         }
 170         void free(CURL *handle)
 171         {
 172                 if (handle)
 173                         handles.push_back(handle);
 174         }
 175 };
 176
 177 struct HTTPFetchOngoing
 178 {
 179         CurlHandlePool *pool;
 180         CURL *curl;
 181         CURLM *multi;
 182         HTTPFetchRequest request;
 183         HTTPFetchResult result;
 184         std::ostringstream oss;
 185         char *post_fields;
 186         struct curl_slist *httpheader;
 187
 188         HTTPFetchOngoing(HTTPFetchRequest request_, CurlHandlePool *pool_):
 189                 pool(pool_),
 190                 curl(NULL),
 191                 multi(NULL),
 192                 request(request_),
 193                 result(request_),
 194                 oss(std::ios::binary),
 195                 httpheader(NULL)
 196         {
 197                 curl = pool->alloc();
 198                 if (curl != NULL) {
 199                         // Set static cURL options
 200                         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 201                         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 202                         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 203                         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 1);
 204
 205 #if LIBCURL_VERSION_NUM >= 0x071304
 206                         // Restrict protocols so that curl vulnerabilities in
 207                         // other protocols don't affect us.
 208                         // These settings were introduced in curl 7.19.4.
 209                         long protocols =
 210                                 CURLPROTO_HTTP |
 211                                 CURLPROTO_HTTPS |
 212                                 CURLPROTO_FTP |
 213                                 CURLPROTO_FTPS;
 214                         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 215                         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 216 #endif
 217
 218                         // Set cURL options based on HTTPFetchRequest
 219                         curl_easy_setopt(curl, CURLOPT_URL,
 220                                         request.url.c_str());
 221                         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 222                                         request.timeout);
 223                         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 224                                         request.connect_timeout);
 225
 226                         if (request.useragent != "")
 227                                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 228
 229                         // Set up a write callback that writes to the
 230                         // ostringstream ongoing->oss, unless the data
 231                         // is to be discarded
 232                         if (request.caller == HTTPFETCH_DISCARD) {
 233                                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 234                                                 httpfetch_discardfunction);
 235                                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 236                         }
 237                         else {
 238                                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 239                                                 httpfetch_writefunction);
 240                                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 241                         }
 242                         // Set POST (or GET) data
 243                         if (request.post_fields.empty()) {
 244                                 curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 245                         }
 246                         else {
 247                                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 248                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 249                                                 request.post_fields.size());
 250                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 251                                                 request.post_fields.c_str());
 252                                 // request.post_fields must now *never* be
 253                                 // modified until CURLOPT_POSTFIELDS is cleared
 254                         }
 255                         // Set additional HTTP headers
 256                         for (size_t i = 0; i < request.extra_headers.size(); ++i) {
 257                                 httpheader = curl_slist_append(
 258                                         httpheader,
 259                                         request.extra_headers[i].c_str());
 260                         }
 261                         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, httpheader);
 262                 }
 263         }
 264
 265         CURLcode start(CURLM *multi_)
 266         {
 267                 if (curl == NULL)
 268                         return CURLE_FAILED_INIT;
 269
 270                 if (multi_) {
 271                         // Multi interface (async)
 272                         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 273                         if (mres != CURLM_OK) {
 274                                 errorstream<<"curl_multi_add_handle"
 275                                         <<" returned error code "<<mres
 276                                         <<std::endl;
 277                                 return CURLE_FAILED_INIT;
 278                         }
 279                         multi = multi_; // store for curl_multi_remove_handle
 280                         return CURLE_OK;
 281                 }
 282                 else {
 283                         // Easy interface (sync)
 284                         return curl_easy_perform(curl);
 285                 }
 286         }
 287
 288         void complete(CURLcode res)
 289         {
 290                 result.succeeded = (res == CURLE_OK);
 291                 result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 292                 result.data = oss.str();
 293
 294                 // Get HTTP/FTP response code
 295                 result.response_code = 0;
 296                 if (curl != NULL) {
 297                         if (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 298                                         &result.response_code) != CURLE_OK) {
 299                                 //we failed to get a return code make sure it is still 0
 300                                 result.response_code = 0;
 301                         }
 302                 }
 303
 304                 if (res != CURLE_OK) {
 305                         infostream<<request.url<<" not found ("
 306                                 <<curl_easy_strerror(res)<<")"
 307                                 <<" (response code "<<result.response_code<<")"
 308                                 <<std::endl;
 309                 }
 310         }
 311
 312         ~HTTPFetchOngoing()
 313         {
 314                 if (multi != NULL) {
 315                         CURLMcode mres = curl_multi_remove_handle(multi, curl);
 316                         if (mres != CURLM_OK) {
 317                                 errorstream<<"curl_multi_remove_handle"
 318                                         <<" returned error code "<<mres
 319                                         <<std::endl;
 320                         }
 321                 }
 322
 323                 // Set safe options for the reusable cURL handle
 324                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 325                                 httpfetch_discardfunction);
 326                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 327                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 328                 if (httpheader != NULL) {
 329                         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 330                         curl_slist_free_all(httpheader);
 331                 }
 332
 333                 // Store the cURL handle for reuse
 334                 pool->free(curl);
 335         }
 336 };
 337
 338 class CurlFetchThread : public JThread
 339 {
 340 protected:
 341         enum RequestType {
 342                 RT_FETCH,
 343                 RT_CLEAR,
 344                 RT_WAKEUP,
 345         };
 346
 347         struct Request {
 348                 RequestType type;
 349                 HTTPFetchRequest fetchrequest;
 350                 Event *event;
 351         };
 352
 353         CURLM *m_multi;
 354         MutexedQueue<Request> m_requests;
 355         size_t m_parallel_limit;
 356
 357         // Variables exclusively used within thread
 358         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 359         std::list<HTTPFetchRequest> m_queued_fetches;
 360
 361 public:
 362         CurlFetchThread(int parallel_limit)
 363         {
 364                 if (parallel_limit >= 1)
 365                         m_parallel_limit = parallel_limit;
 366                 else
 367                         m_parallel_limit = 1;
 368         }
 369
 370         void requestFetch(const HTTPFetchRequest &fetchrequest)
 371         {
 372                 Request req;
 373                 req.type = RT_FETCH;
 374                 req.fetchrequest = fetchrequest;
 375                 req.event = NULL;
 376                 m_requests.push_back(req);
 377         }
 378
 379         void requestClear(unsigned long caller, Event *event)
 380         {
 381                 Request req;
 382                 req.type = RT_CLEAR;
 383                 req.fetchrequest.caller = caller;
 384                 req.event = event;
 385                 m_requests.push_back(req);
 386         }
 387
 388         void requestWakeUp()
 389         {
 390                 Request req;
 391                 req.type = RT_WAKEUP;
 392                 req.event = NULL;
 393                 m_requests.push_back(req);
 394         }
 395
 396 protected:
 397         // Handle a request from some other thread
 398         // E.g. new fetch; clear fetches for one caller; wake up
 399         void processRequest(const Request &req)
 400         {
 401                 if (req.type == RT_FETCH) {
 402                         // New fetch, queue until there are less
 403                         // than m_parallel_limit ongoing fetches
 404                         m_queued_fetches.push_back(req.fetchrequest);
 405
 406                         // see processQueued() for what happens next
 407
 408                 }
 409                 else if (req.type == RT_CLEAR) {
 410                         unsigned long caller = req.fetchrequest.caller;
 411
 412                         // Abort all ongoing fetches for the caller
 413                         for (std::vector<HTTPFetchOngoing*>::iterator
 414                                         it = m_all_ongoing.begin();
 415                                         it != m_all_ongoing.end();) {
 416                                 if ((*it)->request.caller == caller) {
 417                                         delete (*it);
 418                                         it = m_all_ongoing.erase(it);
 419                                 }
 420                                 else
 421                                         ++it;
 422                         }
 423
 424                         // Also abort all queued fetches for the caller
 425                         for (std::list<HTTPFetchRequest>::iterator
 426                                         it = m_queued_fetches.begin();
 427                                         it != m_queued_fetches.end();) {
 428                                 if ((*it).caller == caller)
 429                                         it = m_queued_fetches.erase(it);
 430                                 else
 431                                         ++it;
 432                         }
 433                 }
 434                 else if (req.type == RT_WAKEUP) {
 435                         // Wakeup: Nothing to do, thread is awake at this point
 436                 }
 437
 438                 if (req.event != NULL)
 439                         req.event->signal();
 440         }
 441
 442         // Start new ongoing fetches if m_parallel_limit allows
 443         void processQueued(CurlHandlePool *pool)
 444         {
 445                 while (m_all_ongoing.size() < m_parallel_limit &&
 446                                 !m_queued_fetches.empty()) {
 447                         HTTPFetchRequest request = m_queued_fetches.front();
 448                         m_queued_fetches.pop_front();
 449
 450                         // Create ongoing fetch data and make a cURL handle
 451                         // Set cURL options based on HTTPFetchRequest
 452                         HTTPFetchOngoing *ongoing =
 453                                 new HTTPFetchOngoing(request, pool);
 454
 455                         // Initiate the connection (curl_multi_add_handle)
 456                         CURLcode res = ongoing->start(m_multi);
 457                         if (res == CURLE_OK) {
 458                                 m_all_ongoing.push_back(ongoing);
 459                         }
 460                         else {
 461                                 ongoing->complete(res);
 462                                 httpfetch_deliver_result(ongoing->result);
 463                                 delete ongoing;
 464                         }
 465                 }
 466         }
 467
 468         // Process CURLMsg (indicates completion of a fetch)
 469         void processCurlMessage(CURLMsg *msg)
 470         {
 471                 // Determine which ongoing fetch the message pertains to
 472                 size_t i = 0;
 473                 bool found = false;
 474                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 475                         if (m_all_ongoing[i]->curl == msg->easy_handle) {
 476                                 found = true;
 477                                 break;
 478                         }
 479                 }
 480                 if (msg->msg == CURLMSG_DONE && found) {
 481                         // m_all_ongoing[i] succeeded or failed.
 482                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 483                         ongoing->complete(msg->data.result);
 484                         httpfetch_deliver_result(ongoing->result);
 485                         delete ongoing;
 486                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 487                 }
 488         }
 489
 490         // Wait for a request from another thread, or timeout elapses
 491         void waitForRequest(long timeout)
 492         {
 493                 if (m_queued_fetches.empty()) {
 494                         try {
 495                                 Request req = m_requests.pop_front(timeout);
 496                                 processRequest(req);
 497                         }
 498                         catch (ItemNotFoundException &e) {}
 499                 }
 500         }
 501
 502         // Wait until some IO happens, or timeout elapses
 503         void waitForIO(long timeout)
 504         {
 505                 fd_set read_fd_set;
 506                 fd_set write_fd_set;
 507                 fd_set exc_fd_set;
 508                 int max_fd;
 509                 long select_timeout = -1;
 510                 struct timeval select_tv;
 511                 CURLMcode mres;
 512
 513                 FD_ZERO(&read_fd_set);
 514                 FD_ZERO(&write_fd_set);
 515                 FD_ZERO(&exc_fd_set);
 516
 517                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 518                                 &write_fd_set, &exc_fd_set, &max_fd);
 519                 if (mres != CURLM_OK) {
 520                         errorstream<<"curl_multi_fdset"
 521                                 <<" returned error code "<<mres
 522                                 <<std::endl;
 523                         select_timeout = 0;
 524                 }
 525
 526                 mres = curl_multi_timeout(m_multi, &select_timeout);
 527                 if (mres != CURLM_OK) {
 528                         errorstream<<"curl_multi_timeout"
 529                                 <<" returned error code "<<mres
 530                                 <<std::endl;
 531                         select_timeout = 0;
 532                 }
 533
 534                 // Limit timeout so new requests get through
 535                 if (select_timeout < 0 || select_timeout > timeout)
 536                         select_timeout = timeout;
 537
 538                 if (select_timeout > 0) {
 539                         // in Winsock it is forbidden to pass three empty
 540                         // fd_sets to select(), so in that case use sleep_ms
 541                         if (max_fd != -1) {
 542                                 select_tv.tv_sec = select_timeout / 1000;
 543                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 544                                 int retval = select(max_fd + 1, &read_fd_set,
 545                                                 &write_fd_set, &exc_fd_set,
 546                                                 &select_tv);
 547                                 if (retval == -1) {
 548                                         #ifdef _WIN32
 549                                         errorstream<<"select returned error code "
 550                                                 <<WSAGetLastError()<<std::endl;
 551                                         #else
 552                                         errorstream<<"select returned error code "
 553                                                 <<errno<<std::endl;
 554                                         #endif
 555                                 }
 556                         }
 557                         else {
 558                                 sleep_ms(select_timeout);
 559                         }
 560                 }
 561         }
 562
 563         void * Thread()
 564         {
 565                 ThreadStarted();
 566                 log_register_thread("CurlFetchThread");
 567                 DSTACK(__FUNCTION_NAME);
 568
 569                 porting::setThreadName("CurlFetchThread");
 570
 571                 CurlHandlePool pool;
 572
 573                 m_multi = curl_multi_init();
 574                 if (m_multi == NULL) {
 575                         errorstream<<"curl_multi_init returned NULL\n";
 576                         return NULL;
 577                 }
 578
 579                 assert(m_all_ongoing.empty());
 580
 581                 while (!StopRequested()) {
 582                         BEGIN_DEBUG_EXCEPTION_HANDLER
 583
 584                         /*
 585                                 Handle new async requests
 586                         */
 587
 588                         while (!m_requests.empty()) {
 589                                 Request req = m_requests.pop_frontNoEx();
 590                                 processRequest(req);
 591                         }
 592                         processQueued(&pool);
 593
 594                         /*
 595                                 Handle ongoing async requests
 596                         */
 597
 598                         int still_ongoing = 0;
 599                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 600                                         CURLM_CALL_MULTI_PERFORM)
 601                                 /* noop */;
 602
 603                         /*
 604                                 Handle completed async requests
 605                         */
 606                         if (still_ongoing < (int) m_all_ongoing.size()) {
 607                                 CURLMsg *msg;
 608                                 int msgs_in_queue;
 609                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 610                                 while (msg != NULL) {
 611                                         processCurlMessage(msg);
 612                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 613                                 }
 614                         }
 615
 616                         /*
 617                                 If there are ongoing requests, wait for data
 618                                 (with a timeout of 100ms so that new requests
 619                                 can be processed).
 620
 621                                 If no ongoing requests, wait for a new request.
 622                                 (Possibly an empty request that signals
 623                                 that the thread should be stopped.)
 624                         */
 625                         if (m_all_ongoing.empty())
 626                                 waitForRequest(100000000);
 627                         else
 628                                 waitForIO(100);
 629
 630                         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 631                 }
 632
 633                 // Call curl_multi_remove_handle and cleanup easy handles
 634                 for (size_t i = 0; i < m_all_ongoing.size(); ++i) {
 635                         delete m_all_ongoing[i];
 636                 }
 637                 m_all_ongoing.clear();
 638
 639                 m_queued_fetches.clear();
 640
 641                 CURLMcode mres = curl_multi_cleanup(m_multi);
 642                 if (mres != CURLM_OK) {
 643                         errorstream<<"curl_multi_cleanup"
 644                                 <<" returned error code "<<mres
 645                                 <<std::endl;
 646                 }
 647
 648                 return NULL;
 649         }
 650 };
 651
 652 CurlFetchThread *g_httpfetch_thread = NULL;
 653
 654 void httpfetch_init(int parallel_limit)
 655 {
 656         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 657                         <<std::endl;
 658
 659         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 660         assert(res == CURLE_OK);
 661
 662         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 663 }
 664
 665 void httpfetch_cleanup()
 666 {
 667         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 668
 669         g_httpfetch_thread->Stop();
 670         g_httpfetch_thread->requestWakeUp();
 671         g_httpfetch_thread->Wait();
 672         delete g_httpfetch_thread;
 673
 674         curl_global_cleanup();
 675 }
 676
 677 void httpfetch_async(const HTTPFetchRequest &fetchrequest)
 678 {
 679         g_httpfetch_thread->requestFetch(fetchrequest);
 680         if (!g_httpfetch_thread->IsRunning())
 681                 g_httpfetch_thread->Start();
 682 }
 683
 684 static void httpfetch_request_clear(unsigned long caller)
 685 {
 686         if (g_httpfetch_thread->IsRunning()) {
 687                 Event event;
 688                 g_httpfetch_thread->requestClear(caller, &event);
 689                 event.wait();
 690         }
 691         else {
 692                 g_httpfetch_thread->requestClear(caller, NULL);
 693         }
 694 }
 695
 696 void httpfetch_sync(const HTTPFetchRequest &fetchrequest,
 697                 HTTPFetchResult &fetchresult)
 698 {
 699         // Create ongoing fetch data and make a cURL handle
 700         // Set cURL options based on HTTPFetchRequest
 701         CurlHandlePool pool;
 702         HTTPFetchOngoing ongoing(fetchrequest, &pool);
 703         // Do the fetch (curl_easy_perform)
 704         CURLcode res = ongoing.start(NULL);
 705         // Update fetchresult
 706         ongoing.complete(res);
 707         fetchresult = ongoing.result;
 708 }
 709
 710 #else  // USE_CURL
 711
 712 /*
 713         USE_CURL is off:
 714
 715         Dummy httpfetch implementation that always returns an error.
 716 */
 717
 718 void httpfetch_init(int parallel_limit)
 719 {
 720 }
 721
 722 void httpfetch_cleanup()
 723 {
 724 }
 725
 726 void httpfetch_async(const HTTPFetchRequest &fetchrequest)
 727 {
 728         errorstream<<"httpfetch_async: unable to fetch "<<fetchrequest.url
 729                         <<" because USE_CURL=0"<<std::endl;
 730
 731         HTTPFetchResult fetchresult(fetchrequest); // sets succeeded = false etc.
 732         httpfetch_deliver_result(fetchresult);
 733 }
 734
 735 static void httpfetch_request_clear(unsigned long caller)
 736 {
 737 }
 738
 739 void httpfetch_sync(const HTTPFetchRequest &fetchrequest,
 740                 HTTPFetchResult &fetchresult)
 741 {
 742         errorstream<<"httpfetch_sync: unable to fetch "<<fetchrequest.url
 743                         <<" because USE_CURL=0"<<std::endl;
 744
 745         fetchresult = HTTPFetchResult(fetchrequest); // sets succeeded = false etc.
 746 }
 747
 748 #endif  // USE_CURL