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         multipart = false;
  50
  51         useragent = std::string("Minetest/") + minetest_version_hash + " (" + porting::get_sysinfo() + ")";
  52 }
  53
  54
  55 static void httpfetch_deliver_result(const HTTPFetchResult &fetchresult)
  56 {
  57         unsigned long caller = fetchresult.caller;
  58         if (caller != HTTPFETCH_DISCARD) {
  59                 JMutexAutoLock lock(g_httpfetch_mutex);
  60                 g_httpfetch_results[caller].push_back(fetchresult);
  61         }
  62 }
  63
  64 static void httpfetch_request_clear(unsigned long caller);
  65
  66 unsigned long httpfetch_caller_alloc()
  67 {
  68         JMutexAutoLock lock(g_httpfetch_mutex);
  69
  70         // Check each caller ID except HTTPFETCH_DISCARD
  71         const unsigned long discard = HTTPFETCH_DISCARD;
  72         for (unsigned long caller = discard + 1; caller != discard; ++caller) {
  73                 std::map<unsigned long, std::list<HTTPFetchResult> >::iterator
  74                         it = g_httpfetch_results.find(caller);
  75                 if (it == g_httpfetch_results.end()) {
  76                         verbosestream<<"httpfetch_caller_alloc: allocating "
  77                                         <<caller<<std::endl;
  78                         // Access element to create it
  79                         g_httpfetch_results[caller];
  80                         return caller;
  81                 }
  82         }
  83
  84         assert("httpfetch_caller_alloc: ran out of caller IDs" == 0);
  85         return discard;
  86 }
  87
  88 void httpfetch_caller_free(unsigned long caller)
  89 {
  90         verbosestream<<"httpfetch_caller_free: freeing "
  91                         <<caller<<std::endl;
  92
  93         httpfetch_request_clear(caller);
  94         if (caller != HTTPFETCH_DISCARD) {
  95                 JMutexAutoLock lock(g_httpfetch_mutex);
  96                 g_httpfetch_results.erase(caller);
  97         }
  98 }
  99
 100 bool httpfetch_async_get(unsigned long caller, HTTPFetchResult &fetchresult)
 101 {
 102         JMutexAutoLock lock(g_httpfetch_mutex);
 103
 104         // Check that caller exists
 105         std::map<unsigned long, std::list<HTTPFetchResult> >::iterator
 106                 it = g_httpfetch_results.find(caller);
 107         if (it == g_httpfetch_results.end())
 108                 return false;
 109
 110         // Check that result queue is nonempty
 111         std::list<HTTPFetchResult> &callerresults = it->second;
 112         if (callerresults.empty())
 113                 return false;
 114
 115         // Pop first result
 116         fetchresult = callerresults.front();
 117         callerresults.pop_front();
 118         return true;
 119 }
 120
 121 #if USE_CURL
 122 #include <curl/curl.h>
 123
 124 /*
 125         USE_CURL is on: use cURL based httpfetch implementation
 126 */
 127
 128 static size_t httpfetch_writefunction(
 129                 char *ptr, size_t size, size_t nmemb, void *userdata)
 130 {
 131         std::ostringstream *stream = (std::ostringstream*)userdata;
 132         size_t count = size * nmemb;
 133         stream->write(ptr, count);
 134         return count;
 135 }
 136
 137 static size_t httpfetch_discardfunction(
 138                 char *ptr, size_t size, size_t nmemb, void *userdata)
 139 {
 140         return size * nmemb;
 141 }
 142
 143 class CurlHandlePool
 144 {
 145         std::list<CURL*> handles;
 146
 147 public:
 148         CurlHandlePool() {}
 149         ~CurlHandlePool()
 150         {
 151                 for (std::list<CURL*>::iterator it = handles.begin();
 152                                 it != handles.end(); ++it) {
 153                         curl_easy_cleanup(*it);
 154                 }
 155         }
 156         CURL * alloc()
 157         {
 158                 CURL *curl;
 159                 if (handles.empty()) {
 160                         curl = curl_easy_init();
 161                         if (curl == NULL) {
 162                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 163                         }
 164                 }
 165                 else {
 166                         curl = handles.front();
 167                         handles.pop_front();
 168                 }
 169                 return curl;
 170         }
 171         void free(CURL *handle)
 172         {
 173                 if (handle)
 174                         handles.push_back(handle);
 175         }
 176 };
 177
 178 struct HTTPFetchOngoing
 179 {
 180         CurlHandlePool *pool;
 181         CURL *curl;
 182         CURLM *multi;
 183         HTTPFetchRequest request;
 184         HTTPFetchResult result;
 185         std::ostringstream oss;
 186         char *post_fields;
 187         struct curl_slist *httpheader;
 188         curl_httppost *post;
 189
 190         HTTPFetchOngoing(HTTPFetchRequest request_, CurlHandlePool *pool_):
 191                 pool(pool_),
 192                 curl(NULL),
 193                 multi(NULL),
 194                 request(request_),
 195                 result(request_),
 196                 oss(std::ios::binary),
 197                 httpheader(NULL),
 198                 post(NULL)
 199         {
 200                 curl = pool->alloc();
 201                 if (curl != NULL) {
 202                         // Set static cURL options
 203                         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 204                         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 205                         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 206                         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 1);
 207
 208 #if LIBCURL_VERSION_NUM >= 0x071304
 209                         // Restrict protocols so that curl vulnerabilities in
 210                         // other protocols don't affect us.
 211                         // These settings were introduced in curl 7.19.4.
 212                         long protocols =
 213                                 CURLPROTO_HTTP |
 214                                 CURLPROTO_HTTPS |
 215                                 CURLPROTO_FTP |
 216                                 CURLPROTO_FTPS;
 217                         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 218                         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 219 #endif
 220
 221                         // Set cURL options based on HTTPFetchRequest
 222                         curl_easy_setopt(curl, CURLOPT_URL,
 223                                         request.url.c_str());
 224                         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 225                                         request.timeout);
 226                         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 227                                         request.connect_timeout);
 228
 229                         if (request.useragent != "")
 230                                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 231
 232                         // Set up a write callback that writes to the
 233                         // ostringstream ongoing->oss, unless the data
 234                         // is to be discarded
 235                         if (request.caller == HTTPFETCH_DISCARD) {
 236                                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 237                                                 httpfetch_discardfunction);
 238                                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 239                         }
 240                         else {
 241                                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 242                                                 httpfetch_writefunction);
 243                                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 244                         }
 245
 246                         // Set POST (or GET) data
 247                         if (request.post_fields.empty()) {
 248                                 curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 249                         } else if (request.multipart) {
 250                                 curl_httppost *last = NULL;
 251                                 for (std::map<std::string, std::string>::iterator it =
 252                                                         request.post_fields.begin();
 253                                                 it != request.post_fields.end();
 254                                                 ++it) {
 255                                         curl_formadd(&post, &last,
 256                                                         CURLFORM_NAMELENGTH, it->first.size(),
 257                                                         CURLFORM_PTRNAME, it->first.c_str(),
 258                                                         CURLFORM_CONTENTSLENGTH, it->second.size(),
 259                                                         CURLFORM_PTRCONTENTS, it->second.c_str(),
 260                                                         CURLFORM_END);
 261                                 }
 262                                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
 263                                 // request.post_fields must now *never* be
 264                                 // modified until CURLOPT_HTTPPOST is cleared
 265                         } else {
 266                                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 267                                 if (request.post_data.empty()) {
 268                                         std::string str;
 269                                         for (std::map<std::string, std::string>::iterator it =
 270                                                                 request.post_fields.begin();
 271                                                         it != request.post_fields.end();
 272                                                         ++it) {
 273                                                 if (str != "")
 274                                                         str += "&";
 275                                                 str += urlencode(it->first);
 276                                                 str += "=";
 277                                                 str += urlencode(it->second);
 278                                         }
 279                                         curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 280                                                         str.size());
 281                                         curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
 282                                                         str.c_str());
 283                                 } else {
 284                                         curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 285                                                         request.post_data.size());
 286                                         curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 287                                                         request.post_data.c_str());
 288                                         // request.post_data must now *never* be
 289                                         // modified until CURLOPT_POSTFIELDS is cleared
 290                                 }
 291                         }
 292                         // Set additional HTTP headers
 293                         for (size_t i = 0; i < request.extra_headers.size(); ++i) {
 294                                 httpheader = curl_slist_append(
 295                                         httpheader,
 296                                         request.extra_headers[i].c_str());
 297                         }
 298                         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, httpheader);
 299
 300                         if (!g_settings->getBool("curl_verify_cert")) {
 301                                 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
 302                         }
 303                 }
 304         }
 305
 306         CURLcode start(CURLM *multi_)
 307         {
 308                 if (curl == NULL)
 309                         return CURLE_FAILED_INIT;
 310
 311                 if (multi_) {
 312                         // Multi interface (async)
 313                         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 314                         if (mres != CURLM_OK) {
 315                                 errorstream<<"curl_multi_add_handle"
 316                                         <<" returned error code "<<mres
 317                                         <<std::endl;
 318                                 return CURLE_FAILED_INIT;
 319                         }
 320                         multi = multi_; // store for curl_multi_remove_handle
 321                         return CURLE_OK;
 322                 }
 323                 else {
 324                         // Easy interface (sync)
 325                         return curl_easy_perform(curl);
 326                 }
 327         }
 328
 329         void complete(CURLcode res)
 330         {
 331                 result.succeeded = (res == CURLE_OK);
 332                 result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 333                 result.data = oss.str();
 334
 335                 // Get HTTP/FTP response code
 336                 result.response_code = 0;
 337                 if (curl != NULL) {
 338                         if (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 339                                         &result.response_code) != CURLE_OK) {
 340                                 //we failed to get a return code make sure it is still 0
 341                                 result.response_code = 0;
 342                         }
 343                 }
 344
 345                 if (res != CURLE_OK) {
 346                         errorstream<<request.url<<" not found ("
 347                                 <<curl_easy_strerror(res)<<")"
 348                                 <<" (response code "<<result.response_code<<")"
 349                                 <<std::endl;
 350                 }
 351         }
 352
 353         ~HTTPFetchOngoing()
 354         {
 355                 if (multi != NULL) {
 356                         CURLMcode mres = curl_multi_remove_handle(multi, curl);
 357                         if (mres != CURLM_OK) {
 358                                 errorstream<<"curl_multi_remove_handle"
 359                                         <<" returned error code "<<mres
 360                                         <<std::endl;
 361                         }
 362                 }
 363
 364                 // Set safe options for the reusable cURL handle
 365                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 366                                 httpfetch_discardfunction);
 367                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 368                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 369                 if (httpheader != NULL) {
 370                         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 371                         curl_slist_free_all(httpheader);
 372                 }
 373                 if (post != NULL) {
 374                         curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
 375                         curl_formfree(post);
 376                 }
 377
 378                 // Store the cURL handle for reuse
 379                 pool->free(curl);
 380         }
 381 };
 382
 383 class CurlFetchThread : public JThread
 384 {
 385 protected:
 386         enum RequestType {
 387                 RT_FETCH,
 388                 RT_CLEAR,
 389                 RT_WAKEUP,
 390         };
 391
 392         struct Request {
 393                 RequestType type;
 394                 HTTPFetchRequest fetchrequest;
 395                 Event *event;
 396         };
 397
 398         CURLM *m_multi;
 399         MutexedQueue<Request> m_requests;
 400         size_t m_parallel_limit;
 401
 402         // Variables exclusively used within thread
 403         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 404         std::list<HTTPFetchRequest> m_queued_fetches;
 405
 406 public:
 407         CurlFetchThread(int parallel_limit)
 408         {
 409                 if (parallel_limit >= 1)
 410                         m_parallel_limit = parallel_limit;
 411                 else
 412                         m_parallel_limit = 1;
 413         }
 414
 415         void requestFetch(const HTTPFetchRequest &fetchrequest)
 416         {
 417                 Request req;
 418                 req.type = RT_FETCH;
 419                 req.fetchrequest = fetchrequest;
 420                 req.event = NULL;
 421                 m_requests.push_back(req);
 422         }
 423
 424         void requestClear(unsigned long caller, Event *event)
 425         {
 426                 Request req;
 427                 req.type = RT_CLEAR;
 428                 req.fetchrequest.caller = caller;
 429                 req.event = event;
 430                 m_requests.push_back(req);
 431         }
 432
 433         void requestWakeUp()
 434         {
 435                 Request req;
 436                 req.type = RT_WAKEUP;
 437                 req.event = NULL;
 438                 m_requests.push_back(req);
 439         }
 440
 441 protected:
 442         // Handle a request from some other thread
 443         // E.g. new fetch; clear fetches for one caller; wake up
 444         void processRequest(const Request &req)
 445         {
 446                 if (req.type == RT_FETCH) {
 447                         // New fetch, queue until there are less
 448                         // than m_parallel_limit ongoing fetches
 449                         m_queued_fetches.push_back(req.fetchrequest);
 450
 451                         // see processQueued() for what happens next
 452
 453                 }
 454                 else if (req.type == RT_CLEAR) {
 455                         unsigned long caller = req.fetchrequest.caller;
 456
 457                         // Abort all ongoing fetches for the caller
 458                         for (std::vector<HTTPFetchOngoing*>::iterator
 459                                         it = m_all_ongoing.begin();
 460                                         it != m_all_ongoing.end();) {
 461                                 if ((*it)->request.caller == caller) {
 462                                         delete (*it);
 463                                         it = m_all_ongoing.erase(it);
 464                                 }
 465                                 else
 466                                         ++it;
 467                         }
 468
 469                         // Also abort all queued fetches for the caller
 470                         for (std::list<HTTPFetchRequest>::iterator
 471                                         it = m_queued_fetches.begin();
 472                                         it != m_queued_fetches.end();) {
 473                                 if ((*it).caller == caller)
 474                                         it = m_queued_fetches.erase(it);
 475                                 else
 476                                         ++it;
 477                         }
 478                 }
 479                 else if (req.type == RT_WAKEUP) {
 480                         // Wakeup: Nothing to do, thread is awake at this point
 481                 }
 482
 483                 if (req.event != NULL)
 484                         req.event->signal();
 485         }
 486
 487         // Start new ongoing fetches if m_parallel_limit allows
 488         void processQueued(CurlHandlePool *pool)
 489         {
 490                 while (m_all_ongoing.size() < m_parallel_limit &&
 491                                 !m_queued_fetches.empty()) {
 492                         HTTPFetchRequest request = m_queued_fetches.front();
 493                         m_queued_fetches.pop_front();
 494
 495                         // Create ongoing fetch data and make a cURL handle
 496                         // Set cURL options based on HTTPFetchRequest
 497                         HTTPFetchOngoing *ongoing =
 498                                 new HTTPFetchOngoing(request, pool);
 499
 500                         // Initiate the connection (curl_multi_add_handle)
 501                         CURLcode res = ongoing->start(m_multi);
 502                         if (res == CURLE_OK) {
 503                                 m_all_ongoing.push_back(ongoing);
 504                         }
 505                         else {
 506                                 ongoing->complete(res);
 507                                 httpfetch_deliver_result(ongoing->result);
 508                                 delete ongoing;
 509                         }
 510                 }
 511         }
 512
 513         // Process CURLMsg (indicates completion of a fetch)
 514         void processCurlMessage(CURLMsg *msg)
 515         {
 516                 // Determine which ongoing fetch the message pertains to
 517                 size_t i = 0;
 518                 bool found = false;
 519                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 520                         if (m_all_ongoing[i]->curl == msg->easy_handle) {
 521                                 found = true;
 522                                 break;
 523                         }
 524                 }
 525                 if (msg->msg == CURLMSG_DONE && found) {
 526                         // m_all_ongoing[i] succeeded or failed.
 527                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 528                         ongoing->complete(msg->data.result);
 529                         httpfetch_deliver_result(ongoing->result);
 530                         delete ongoing;
 531                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 532                 }
 533         }
 534
 535         // Wait for a request from another thread, or timeout elapses
 536         void waitForRequest(long timeout)
 537         {
 538                 if (m_queued_fetches.empty()) {
 539                         try {
 540                                 Request req = m_requests.pop_front(timeout);
 541                                 processRequest(req);
 542                         }
 543                         catch (ItemNotFoundException &e) {}
 544                 }
 545         }
 546
 547         // Wait until some IO happens, or timeout elapses
 548         void waitForIO(long timeout)
 549         {
 550                 fd_set read_fd_set;
 551                 fd_set write_fd_set;
 552                 fd_set exc_fd_set;
 553                 int max_fd;
 554                 long select_timeout = -1;
 555                 struct timeval select_tv;
 556                 CURLMcode mres;
 557
 558                 FD_ZERO(&read_fd_set);
 559                 FD_ZERO(&write_fd_set);
 560                 FD_ZERO(&exc_fd_set);
 561
 562                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 563                                 &write_fd_set, &exc_fd_set, &max_fd);
 564                 if (mres != CURLM_OK) {
 565                         errorstream<<"curl_multi_fdset"
 566                                 <<" returned error code "<<mres
 567                                 <<std::endl;
 568                         select_timeout = 0;
 569                 }
 570
 571                 mres = curl_multi_timeout(m_multi, &select_timeout);
 572                 if (mres != CURLM_OK) {
 573                         errorstream<<"curl_multi_timeout"
 574                                 <<" returned error code "<<mres
 575                                 <<std::endl;
 576                         select_timeout = 0;
 577                 }
 578
 579                 // Limit timeout so new requests get through
 580                 if (select_timeout < 0 || select_timeout > timeout)
 581                         select_timeout = timeout;
 582
 583                 if (select_timeout > 0) {
 584                         // in Winsock it is forbidden to pass three empty
 585                         // fd_sets to select(), so in that case use sleep_ms
 586                         if (max_fd != -1) {
 587                                 select_tv.tv_sec = select_timeout / 1000;
 588                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 589                                 int retval = select(max_fd + 1, &read_fd_set,
 590                                                 &write_fd_set, &exc_fd_set,
 591                                                 &select_tv);
 592                                 if (retval == -1) {
 593                                         #ifdef _WIN32
 594                                         errorstream<<"select returned error code "
 595                                                 <<WSAGetLastError()<<std::endl;
 596                                         #else
 597                                         errorstream<<"select returned error code "
 598                                                 <<errno<<std::endl;
 599                                         #endif
 600                                 }
 601                         }
 602                         else {
 603                                 sleep_ms(select_timeout);
 604                         }
 605                 }
 606         }
 607
 608         void * Thread()
 609         {
 610                 ThreadStarted();
 611                 log_register_thread("CurlFetchThread");
 612                 DSTACK(__FUNCTION_NAME);
 613
 614                 porting::setThreadName("CurlFetchThread");
 615
 616                 CurlHandlePool pool;
 617
 618                 m_multi = curl_multi_init();
 619                 if (m_multi == NULL) {
 620                         errorstream<<"curl_multi_init returned NULL\n";
 621                         return NULL;
 622                 }
 623
 624                 assert(m_all_ongoing.empty());
 625
 626                 while (!StopRequested()) {
 627                         BEGIN_DEBUG_EXCEPTION_HANDLER
 628
 629                         /*
 630                                 Handle new async requests
 631                         */
 632
 633                         while (!m_requests.empty()) {
 634                                 Request req = m_requests.pop_frontNoEx();
 635                                 processRequest(req);
 636                         }
 637                         processQueued(&pool);
 638
 639                         /*
 640                                 Handle ongoing async requests
 641                         */
 642
 643                         int still_ongoing = 0;
 644                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 645                                         CURLM_CALL_MULTI_PERFORM)
 646                                 /* noop */;
 647
 648                         /*
 649                                 Handle completed async requests
 650                         */
 651                         if (still_ongoing < (int) m_all_ongoing.size()) {
 652                                 CURLMsg *msg;
 653                                 int msgs_in_queue;
 654                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 655                                 while (msg != NULL) {
 656                                         processCurlMessage(msg);
 657                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 658                                 }
 659                         }
 660
 661                         /*
 662                                 If there are ongoing requests, wait for data
 663                                 (with a timeout of 100ms so that new requests
 664                                 can be processed).
 665
 666                                 If no ongoing requests, wait for a new request.
 667                                 (Possibly an empty request that signals
 668                                 that the thread should be stopped.)
 669                         */
 670                         if (m_all_ongoing.empty())
 671                                 waitForRequest(100000000);
 672                         else
 673                                 waitForIO(100);
 674
 675                         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 676                 }
 677
 678                 // Call curl_multi_remove_handle and cleanup easy handles
 679                 for (size_t i = 0; i < m_all_ongoing.size(); ++i) {
 680                         delete m_all_ongoing[i];
 681                 }
 682                 m_all_ongoing.clear();
 683
 684                 m_queued_fetches.clear();
 685
 686                 CURLMcode mres = curl_multi_cleanup(m_multi);
 687                 if (mres != CURLM_OK) {
 688                         errorstream<<"curl_multi_cleanup"
 689                                 <<" returned error code "<<mres
 690                                 <<std::endl;
 691                 }
 692
 693                 return NULL;
 694         }
 695 };
 696
 697 CurlFetchThread *g_httpfetch_thread = NULL;
 698
 699 void httpfetch_init(int parallel_limit)
 700 {
 701         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 702                         <<std::endl;
 703
 704         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 705         assert(res == CURLE_OK);
 706
 707         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 708 }
 709
 710 void httpfetch_cleanup()
 711 {
 712         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 713
 714         g_httpfetch_thread->Stop();
 715         g_httpfetch_thread->requestWakeUp();
 716         g_httpfetch_thread->Wait();
 717         delete g_httpfetch_thread;
 718
 719         curl_global_cleanup();
 720 }
 721
 722 void httpfetch_async(const HTTPFetchRequest &fetchrequest)
 723 {
 724         g_httpfetch_thread->requestFetch(fetchrequest);
 725         if (!g_httpfetch_thread->IsRunning())
 726                 g_httpfetch_thread->Start();
 727 }
 728
 729 static void httpfetch_request_clear(unsigned long caller)
 730 {
 731         if (g_httpfetch_thread->IsRunning()) {
 732                 Event event;
 733                 g_httpfetch_thread->requestClear(caller, &event);
 734                 event.wait();
 735         }
 736         else {
 737                 g_httpfetch_thread->requestClear(caller, NULL);
 738         }
 739 }
 740
 741 void httpfetch_sync(const HTTPFetchRequest &fetchrequest,
 742                 HTTPFetchResult &fetchresult)
 743 {
 744         // Create ongoing fetch data and make a cURL handle
 745         // Set cURL options based on HTTPFetchRequest
 746         CurlHandlePool pool;
 747         HTTPFetchOngoing ongoing(fetchrequest, &pool);
 748         // Do the fetch (curl_easy_perform)
 749         CURLcode res = ongoing.start(NULL);
 750         // Update fetchresult
 751         ongoing.complete(res);
 752         fetchresult = ongoing.result;
 753 }
 754
 755 #else  // USE_CURL
 756
 757 /*
 758         USE_CURL is off:
 759
 760         Dummy httpfetch implementation that always returns an error.
 761 */
 762
 763 void httpfetch_init(int parallel_limit)
 764 {
 765 }
 766
 767 void httpfetch_cleanup()
 768 {
 769 }
 770
 771 void httpfetch_async(const HTTPFetchRequest &fetchrequest)
 772 {
 773         errorstream<<"httpfetch_async: unable to fetch "<<fetchrequest.url
 774                         <<" because USE_CURL=0"<<std::endl;
 775
 776         HTTPFetchResult fetchresult(fetchrequest); // sets succeeded = false etc.
 777         httpfetch_deliver_result(fetchresult);
 778 }
 779
 780 static void httpfetch_request_clear(unsigned long caller)
 781 {
 782 }
 783
 784 void httpfetch_sync(const HTTPFetchRequest &fetchrequest,
 785                 HTTPFetchResult &fetchresult)
 786 {
 787         errorstream<<"httpfetch_sync: unable to fetch "<<fetchrequest.url
 788                         <<" because USE_CURL=0"<<std::endl;
 789
 790         fetchresult = HTTPFetchResult(fetchrequest); // sets succeeded = false etc.
 791 }
 792
 793 #endif  // USE_CURL