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()
  22 #include "httpfetch.h"
  23 #include <iostream>
  24 #include <sstream>
  25 #include <list>
  26 #include <map>
  27 #include <errno.h>
  28 #ifndef _MSC_VER
  29 #include <sys/utsname.h>
  30 #endif
  31 #include "jthread/jevent.h"
  32 #include "config.h"
  33 #include "exceptions.h"
  34 #include "debug.h"
  35 #include "log.h"
  36 #include "util/container.h"
  37 #include "util/thread.h"
  38 #include "version.h"
  39 #include "main.h"
  40 #include "settings.h"
  41
  42 JMutex g_httpfetch_mutex;
  43 std::map<unsigned long, std::list<HTTPFetchResult> > g_httpfetch_results;
  44
  45         HTTPFetchRequest::HTTPFetchRequest()
  46         {
  47                 url = "";
  48                 caller = HTTPFETCH_DISCARD;
  49                 request_id = 0;
  50                 timeout = g_settings->getS32("curl_timeout");
  51                 connect_timeout = timeout * 5;
  52
  53                 useragent = std::string("Minetest ") + minetest_version_hash;
  54 #ifdef _MSC_VER
  55                 useragent += "Windows";
  56 #else
  57                 struct utsname osinfo;
  58                 uname(&osinfo);
  59                 useragent += std::string(" (") + osinfo.sysname + "; " + osinfo.release + "; " + osinfo.machine + ")";
  60 #endif
  61         }
  62
  63
  64 static void httpfetch_deliver_result(const HTTPFetchResult &fetchresult)
  65 {
  66         unsigned long caller = fetchresult.caller;
  67         if (caller != HTTPFETCH_DISCARD) {
  68                 JMutexAutoLock lock(g_httpfetch_mutex);
  69                 g_httpfetch_results[caller].push_back(fetchresult);
  70         }
  71 }
  72
  73 static void httpfetch_request_clear(unsigned long caller);
  74
  75 unsigned long httpfetch_caller_alloc()
  76 {
  77         JMutexAutoLock lock(g_httpfetch_mutex);
  78
  79         // Check each caller ID except HTTPFETCH_DISCARD
  80         const unsigned long discard = HTTPFETCH_DISCARD;
  81         for (unsigned long caller = discard + 1; caller != discard; ++caller) {
  82                 std::map<unsigned long, std::list<HTTPFetchResult> >::iterator
  83                         it = g_httpfetch_results.find(caller);
  84                 if (it == g_httpfetch_results.end()) {
  85                         verbosestream<<"httpfetch_caller_alloc: allocating "
  86                                         <<caller<<std::endl;
  87                         // Access element to create it
  88                         g_httpfetch_results[caller];
  89                         return caller;
  90                 }
  91         }
  92
  93         assert("httpfetch_caller_alloc: ran out of caller IDs" == 0);
  94         return discard;
  95 }
  96
  97 void httpfetch_caller_free(unsigned long caller)
  98 {
  99         verbosestream<<"httpfetch_caller_free: freeing "
 100                         <<caller<<std::endl;
 101
 102         httpfetch_request_clear(caller);
 103         if (caller != HTTPFETCH_DISCARD) {
 104                 JMutexAutoLock lock(g_httpfetch_mutex);
 105                 g_httpfetch_results.erase(caller);
 106         }
 107 }
 108
 109 bool httpfetch_async_get(unsigned long caller, HTTPFetchResult &fetchresult)
 110 {
 111         JMutexAutoLock lock(g_httpfetch_mutex);
 112
 113         // Check that caller exists
 114         std::map<unsigned long, std::list<HTTPFetchResult> >::iterator
 115                 it = g_httpfetch_results.find(caller);
 116         if (it == g_httpfetch_results.end())
 117                 return false;
 118
 119         // Check that result queue is nonempty
 120         std::list<HTTPFetchResult> &callerresults = it->second;
 121         if (callerresults.empty())
 122                 return false;
 123
 124         // Pop first result
 125         fetchresult = callerresults.front();
 126         callerresults.pop_front();
 127         return true;
 128 }
 129
 130 #if USE_CURL
 131 #include <curl/curl.h>
 132
 133 /*
 134         USE_CURL is on: use cURL based httpfetch implementation
 135 */
 136
 137 static size_t httpfetch_writefunction(
 138                 char *ptr, size_t size, size_t nmemb, void *userdata)
 139 {
 140         std::ostringstream *stream = (std::ostringstream*)userdata;
 141         size_t count = size * nmemb;
 142         stream->write(ptr, count);
 143         return count;
 144 }
 145
 146 static size_t httpfetch_discardfunction(
 147                 char *ptr, size_t size, size_t nmemb, void *userdata)
 148 {
 149         return size * nmemb;
 150 }
 151
 152 class CurlHandlePool
 153 {
 154         std::list<CURL*> handles;
 155
 156 public:
 157         CurlHandlePool() {}
 158         ~CurlHandlePool()
 159         {
 160                 for (std::list<CURL*>::iterator it = handles.begin();
 161                                 it != handles.end(); ++it) {
 162                         curl_easy_cleanup(*it);
 163                 }
 164         }
 165         CURL * alloc()
 166         {
 167                 CURL *curl;
 168                 if (handles.empty()) {
 169                         curl = curl_easy_init();
 170                         if (curl == NULL) {
 171                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 172                         }
 173                 }
 174                 else {
 175                         curl = handles.front();
 176                         handles.pop_front();
 177                 }
 178                 return curl;
 179         }
 180         void free(CURL *handle)
 181         {
 182                 if (handle)
 183                         handles.push_back(handle);
 184         }
 185 };
 186
 187 struct HTTPFetchOngoing
 188 {
 189         CurlHandlePool *pool;
 190         CURL *curl;
 191         CURLM *multi;
 192         HTTPFetchRequest request;
 193         HTTPFetchResult result;
 194         std::ostringstream oss;
 195         char *post_fields;
 196         struct curl_slist *httpheader;
 197
 198         HTTPFetchOngoing(HTTPFetchRequest request_, CurlHandlePool *pool_):
 199                 pool(pool_),
 200                 curl(NULL),
 201                 multi(NULL),
 202                 request(request_),
 203                 result(request_),
 204                 oss(std::ios::binary),
 205                 httpheader(NULL)
 206         {
 207                 curl = pool->alloc();
 208                 if (curl != NULL) {
 209                         // Set static cURL options
 210                         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 211                         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 212                         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 213                         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 1);
 214
 215 #if LIBCURL_VERSION_NUM >= 0x071304
 216                         // Restrict protocols so that curl vulnerabilities in
 217                         // other protocols don't affect us.
 218                         // These settings were introduced in curl 7.19.4.
 219                         long protocols =
 220                                 CURLPROTO_HTTP |
 221                                 CURLPROTO_HTTPS |
 222                                 CURLPROTO_FTP |
 223                                 CURLPROTO_FTPS;
 224                         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 225                         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 226 #endif
 227
 228                         // Set cURL options based on HTTPFetchRequest
 229                         curl_easy_setopt(curl, CURLOPT_URL,
 230                                         request.url.c_str());
 231                         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 232                                         request.timeout);
 233                         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 234                                         request.connect_timeout);
 235
 236                         if (request.useragent != "")
 237                                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 238
 239                         // Set up a write callback that writes to the
 240                         // ostringstream ongoing->oss, unless the data
 241                         // is to be discarded
 242                         if (request.caller == HTTPFETCH_DISCARD) {
 243                                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 244                                                 httpfetch_discardfunction);
 245                                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 246                         }
 247                         else {
 248                                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 249                                                 httpfetch_writefunction);
 250                                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 251                         }
 252                         // Set POST (or GET) data
 253                         if (request.post_fields.empty()) {
 254                                 curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 255                         }
 256                         else {
 257                                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 258                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 259                                                 request.post_fields.size());
 260                                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 261                                                 request.post_fields.c_str());
 262                                 // request.post_fields must now *never* be
 263                                 // modified until CURLOPT_POSTFIELDS is cleared
 264                         }
 265                         // Set additional HTTP headers
 266                         for (size_t i = 0; i < request.extra_headers.size(); ++i) {
 267                                 httpheader = curl_slist_append(
 268                                         httpheader,
 269                                         request.extra_headers[i].c_str());
 270                         }
 271                         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, httpheader);
 272                 }
 273         }
 274
 275         CURLcode start(CURLM *multi_)
 276         {
 277                 if (curl == NULL)
 278                         return CURLE_FAILED_INIT;
 279
 280                 if (multi_) {
 281                         // Multi interface (async)
 282                         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 283                         if (mres != CURLM_OK) {
 284                                 errorstream<<"curl_multi_add_handle"
 285                                         <<" returned error code "<<mres
 286                                         <<std::endl;
 287                                 return CURLE_FAILED_INIT;
 288                         }
 289                         multi = multi_; // store for curl_multi_remove_handle
 290                         return CURLE_OK;
 291                 }
 292                 else {
 293                         // Easy interface (sync)
 294                         return curl_easy_perform(curl);
 295                 }
 296         }
 297
 298         void complete(CURLcode res)
 299         {
 300                 result.succeeded = (res == CURLE_OK);
 301                 result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 302                 result.data = oss.str();
 303
 304                 // Get HTTP/FTP response code
 305                 result.response_code = 0;
 306                 if (curl != NULL) {
 307                         if (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 308                                         &result.response_code) != CURLE_OK) {
 309                                 //we failed to get a return code make sure it is still 0
 310                                 result.response_code = 0;
 311                         }
 312                 }
 313
 314                 if (res != CURLE_OK) {
 315                         infostream<<request.url<<" not found ("
 316                                 <<curl_easy_strerror(res)<<")"
 317                                 <<" (response code "<<result.response_code<<")"
 318                                 <<std::endl;
 319                 }
 320         }
 321
 322         ~HTTPFetchOngoing()
 323         {
 324                 if (multi != NULL) {
 325                         CURLMcode mres = curl_multi_remove_handle(multi, curl);
 326                         if (mres != CURLM_OK) {
 327                                 errorstream<<"curl_multi_remove_handle"
 328                                         <<" returned error code "<<mres
 329                                         <<std::endl;
 330                         }
 331                 }
 332
 333                 // Set safe options for the reusable cURL handle
 334                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 335                                 httpfetch_discardfunction);
 336                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 337                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 338                 if (httpheader != NULL) {
 339                         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 340                         curl_slist_free_all(httpheader);
 341                 }
 342
 343                 // Store the cURL handle for reuse
 344                 pool->free(curl);
 345         }
 346 };
 347
 348 class CurlFetchThread : public JThread
 349 {
 350 protected:
 351         enum RequestType {
 352                 RT_FETCH,
 353                 RT_CLEAR,
 354                 RT_WAKEUP,
 355         };
 356
 357         struct Request {
 358                 RequestType type;
 359                 HTTPFetchRequest fetchrequest;
 360                 Event *event;
 361         };
 362
 363         CURLM *m_multi;
 364         MutexedQueue<Request> m_requests;
 365         size_t m_parallel_limit;
 366
 367         // Variables exclusively used within thread
 368         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 369         std::list<HTTPFetchRequest> m_queued_fetches;
 370
 371 public:
 372         CurlFetchThread(int parallel_limit)
 373         {
 374                 if (parallel_limit >= 1)
 375                         m_parallel_limit = parallel_limit;
 376                 else
 377                         m_parallel_limit = 1;
 378         }
 379
 380         void requestFetch(const HTTPFetchRequest &fetchrequest)
 381         {
 382                 Request req;
 383                 req.type = RT_FETCH;
 384                 req.fetchrequest = fetchrequest;
 385                 req.event = NULL;
 386                 m_requests.push_back(req);
 387         }
 388
 389         void requestClear(unsigned long caller, Event *event)
 390         {
 391                 Request req;
 392                 req.type = RT_CLEAR;
 393                 req.fetchrequest.caller = caller;
 394                 req.event = event;
 395                 m_requests.push_back(req);
 396         }
 397
 398         void requestWakeUp()
 399         {
 400                 Request req;
 401                 req.type = RT_WAKEUP;
 402                 req.event = NULL;
 403                 m_requests.push_back(req);
 404         }
 405
 406 protected:
 407         // Handle a request from some other thread
 408         // E.g. new fetch; clear fetches for one caller; wake up
 409         void processRequest(const Request &req)
 410         {
 411                 if (req.type == RT_FETCH) {
 412                         // New fetch, queue until there are less
 413                         // than m_parallel_limit ongoing fetches
 414                         m_queued_fetches.push_back(req.fetchrequest);
 415
 416                         // see processQueued() for what happens next
 417
 418                 }
 419                 else if (req.type == RT_CLEAR) {
 420                         unsigned long caller = req.fetchrequest.caller;
 421
 422                         // Abort all ongoing fetches for the caller
 423                         for (std::vector<HTTPFetchOngoing*>::iterator
 424                                         it = m_all_ongoing.begin();
 425                                         it != m_all_ongoing.end();) {
 426                                 if ((*it)->request.caller == caller) {
 427                                         delete (*it);
 428                                         it = m_all_ongoing.erase(it);
 429                                 }
 430                                 else
 431                                         ++it;
 432                         }
 433
 434                         // Also abort all queued fetches for the caller
 435                         for (std::list<HTTPFetchRequest>::iterator
 436                                         it = m_queued_fetches.begin();
 437                                         it != m_queued_fetches.end();) {
 438                                 if ((*it).caller == caller)
 439                                         it = m_queued_fetches.erase(it);
 440                                 else
 441                                         ++it;
 442                         }
 443                 }
 444                 else if (req.type == RT_WAKEUP) {
 445                         // Wakeup: Nothing to do, thread is awake at this point
 446                 }
 447
 448                 if (req.event != NULL)
 449                         req.event->signal();
 450         }
 451
 452         // Start new ongoing fetches if m_parallel_limit allows
 453         void processQueued(CurlHandlePool *pool)
 454         {
 455                 while (m_all_ongoing.size() < m_parallel_limit &&
 456                                 !m_queued_fetches.empty()) {
 457                         HTTPFetchRequest request = m_queued_fetches.front();
 458                         m_queued_fetches.pop_front();
 459
 460                         // Create ongoing fetch data and make a cURL handle
 461                         // Set cURL options based on HTTPFetchRequest
 462                         HTTPFetchOngoing *ongoing =
 463                                 new HTTPFetchOngoing(request, pool);
 464
 465                         // Initiate the connection (curl_multi_add_handle)
 466                         CURLcode res = ongoing->start(m_multi);
 467                         if (res == CURLE_OK) {
 468                                 m_all_ongoing.push_back(ongoing);
 469                         }
 470                         else {
 471                                 ongoing->complete(res);
 472                                 httpfetch_deliver_result(ongoing->result);
 473                                 delete ongoing;
 474                         }
 475                 }
 476         }
 477
 478         // Process CURLMsg (indicates completion of a fetch)
 479         void processCurlMessage(CURLMsg *msg)
 480         {
 481                 // Determine which ongoing fetch the message pertains to
 482                 size_t i = 0;
 483                 bool found = false;
 484                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 485                         if (m_all_ongoing[i]->curl == msg->easy_handle) {
 486                                 found = true;
 487                                 break;
 488                         }
 489                 }
 490                 if (msg->msg == CURLMSG_DONE && found) {
 491                         // m_all_ongoing[i] succeeded or failed.
 492                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 493                         ongoing->complete(msg->data.result);
 494                         httpfetch_deliver_result(ongoing->result);
 495                         delete ongoing;
 496                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 497                 }
 498         }
 499
 500         // Wait for a request from another thread, or timeout elapses
 501         void waitForRequest(long timeout)
 502         {
 503                 if (m_queued_fetches.empty()) {
 504                         try {
 505                                 Request req = m_requests.pop_front(timeout);
 506                                 processRequest(req);
 507                         }
 508                         catch (ItemNotFoundException &e) {}
 509                 }
 510         }
 511
 512         // Wait until some IO happens, or timeout elapses
 513         void waitForIO(long timeout)
 514         {
 515                 fd_set read_fd_set;
 516                 fd_set write_fd_set;
 517                 fd_set exc_fd_set;
 518                 int max_fd;
 519                 long select_timeout = -1;
 520                 struct timeval select_tv;
 521                 CURLMcode mres;
 522
 523                 FD_ZERO(&read_fd_set);
 524                 FD_ZERO(&write_fd_set);
 525                 FD_ZERO(&exc_fd_set);
 526
 527                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 528                                 &write_fd_set, &exc_fd_set, &max_fd);
 529                 if (mres != CURLM_OK) {
 530                         errorstream<<"curl_multi_fdset"
 531                                 <<" returned error code "<<mres
 532                                 <<std::endl;
 533                         select_timeout = 0;
 534                 }
 535
 536                 mres = curl_multi_timeout(m_multi, &select_timeout);
 537                 if (mres != CURLM_OK) {
 538                         errorstream<<"curl_multi_timeout"
 539                                 <<" returned error code "<<mres
 540                                 <<std::endl;
 541                         select_timeout = 0;
 542                 }
 543
 544                 // Limit timeout so new requests get through
 545                 if (select_timeout < 0 || select_timeout > timeout)
 546                         select_timeout = timeout;
 547
 548                 if (select_timeout > 0) {
 549                         // in Winsock it is forbidden to pass three empty
 550                         // fd_sets to select(), so in that case use sleep_ms
 551                         if (max_fd != -1) {
 552                                 select_tv.tv_sec = select_timeout / 1000;
 553                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 554                                 int retval = select(max_fd + 1, &read_fd_set,
 555                                                 &write_fd_set, &exc_fd_set,
 556                                                 &select_tv);
 557                                 if (retval == -1) {
 558                                         #ifdef _WIN32
 559                                         errorstream<<"select returned error code "
 560                                                 <<WSAGetLastError()<<std::endl;
 561                                         #else
 562                                         errorstream<<"select returned error code "
 563                                                 <<errno<<std::endl;
 564                                         #endif
 565                                 }
 566                         }
 567                         else {
 568                                 sleep_ms(select_timeout);
 569                         }
 570                 }
 571         }
 572
 573         void * Thread()
 574         {
 575                 ThreadStarted();
 576                 log_register_thread("CurlFetchThread");
 577                 DSTACK(__FUNCTION_NAME);
 578
 579                 CurlHandlePool pool;
 580
 581                 m_multi = curl_multi_init();
 582                 if (m_multi == NULL) {
 583                         errorstream<<"curl_multi_init returned NULL\n";
 584                         return NULL;
 585                 }
 586
 587                 assert(m_all_ongoing.empty());
 588
 589                 while (!StopRequested()) {
 590                         BEGIN_DEBUG_EXCEPTION_HANDLER
 591
 592                         /*
 593                                 Handle new async requests
 594                         */
 595
 596                         while (!m_requests.empty()) {
 597                                 Request req = m_requests.pop_frontNoEx();
 598                                 processRequest(req);
 599                         }
 600                         processQueued(&pool);
 601
 602                         /*
 603                                 Handle ongoing async requests
 604                         */
 605
 606                         int still_ongoing = 0;
 607                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 608                                         CURLM_CALL_MULTI_PERFORM)
 609                                 /* noop */;
 610
 611                         /*
 612                                 Handle completed async requests
 613                         */
 614                         if (still_ongoing < (int) m_all_ongoing.size()) {
 615                                 CURLMsg *msg;
 616                                 int msgs_in_queue;
 617                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 618                                 while (msg != NULL) {
 619                                         processCurlMessage(msg);
 620                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 621                                 }
 622                         }
 623
 624                         /*
 625                                 If there are ongoing requests, wait for data
 626                                 (with a timeout of 100ms so that new requests
 627                                 can be processed).
 628
 629                                 If no ongoing requests, wait for a new request.
 630                                 (Possibly an empty request that signals
 631                                 that the thread should be stopped.)
 632                         */
 633                         if (m_all_ongoing.empty())
 634                                 waitForRequest(100000000);
 635                         else
 636                                 waitForIO(100);
 637
 638                         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 639                 }
 640
 641                 // Call curl_multi_remove_handle and cleanup easy handles
 642                 for (size_t i = 0; i < m_all_ongoing.size(); ++i) {
 643                         delete m_all_ongoing[i];
 644                 }
 645                 m_all_ongoing.clear();
 646
 647                 m_queued_fetches.clear();
 648
 649                 CURLMcode mres = curl_multi_cleanup(m_multi);
 650                 if (mres != CURLM_OK) {
 651                         errorstream<<"curl_multi_cleanup"
 652                                 <<" returned error code "<<mres
 653                                 <<std::endl;
 654                 }
 655
 656                 return NULL;
 657         }
 658 };
 659
 660 CurlFetchThread *g_httpfetch_thread = NULL;
 661
 662 void httpfetch_init(int parallel_limit)
 663 {
 664         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 665                         <<std::endl;
 666
 667         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 668         assert(res == CURLE_OK);
 669
 670         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 671 }
 672
 673 void httpfetch_cleanup()
 674 {
 675         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 676
 677         g_httpfetch_thread->Stop();
 678         g_httpfetch_thread->requestWakeUp();
 679         g_httpfetch_thread->Wait();
 680         delete g_httpfetch_thread;
 681
 682         curl_global_cleanup();
 683 }
 684
 685 void httpfetch_async(const HTTPFetchRequest &fetchrequest)
 686 {
 687         g_httpfetch_thread->requestFetch(fetchrequest);
 688         if (!g_httpfetch_thread->IsRunning())
 689                 g_httpfetch_thread->Start();
 690 }
 691
 692 static void httpfetch_request_clear(unsigned long caller)
 693 {
 694         if (g_httpfetch_thread->IsRunning()) {
 695                 Event event;
 696                 g_httpfetch_thread->requestClear(caller, &event);
 697                 event.wait();
 698         }
 699         else {
 700                 g_httpfetch_thread->requestClear(caller, NULL);
 701         }
 702 }
 703
 704 void httpfetch_sync(const HTTPFetchRequest &fetchrequest,
 705                 HTTPFetchResult &fetchresult)
 706 {
 707         // Create ongoing fetch data and make a cURL handle
 708         // Set cURL options based on HTTPFetchRequest
 709         CurlHandlePool pool;
 710         HTTPFetchOngoing ongoing(fetchrequest, &pool);
 711         // Do the fetch (curl_easy_perform)
 712         CURLcode res = ongoing.start(NULL);
 713         // Update fetchresult
 714         ongoing.complete(res);
 715         fetchresult = ongoing.result;
 716 }
 717
 718 #else  // USE_CURL
 719
 720 /*
 721         USE_CURL is off:
 722
 723         Dummy httpfetch implementation that always returns an error.
 724 */
 725
 726 void httpfetch_init(int parallel_limit)
 727 {
 728 }
 729
 730 void httpfetch_cleanup()
 731 {
 732 }
 733
 734 void httpfetch_async(const HTTPFetchRequest &fetchrequest)
 735 {
 736         errorstream<<"httpfetch_async: unable to fetch "<<fetchrequest.url
 737                         <<" because USE_CURL=0"<<std::endl;
 738
 739         HTTPFetchResult fetchresult(fetchrequest); // sets succeeded = false etc.
 740         httpfetch_deliver_result(fetchresult);
 741 }
 742
 743 static void httpfetch_request_clear(unsigned long caller)
 744 {
 745 }
 746
 747 void httpfetch_sync(const HTTPFetchRequest &fetchrequest,
 748                 HTTPFetchResult &fetchresult)
 749 {
 750         errorstream<<"httpfetch_sync: unable to fetch "<<fetchrequest.url
 751                         <<" because USE_CURL=0"<<std::endl;
 752
 753         fetchresult = HTTPFetchResult(fetchrequest); // sets succeeded = false etc.
 754 }
 755
 756 #endif  // USE_CURL