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 &fetch_result)
  56 {
  57         unsigned long caller = fetch_result.caller;
  58         if (caller != HTTPFETCH_DISCARD) {
  59                 JMutexAutoLock lock(g_httpfetch_mutex);
  60                 g_httpfetch_results[caller].push_back(fetch_result);
  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 &fetch_result)
 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> &caller_results = it->second;
 112         if (caller_results.empty())
 113                 return false;
 114
 115         // Pop first result
 116         fetch_result = caller_results.front();
 117         caller_results.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 class HTTPFetchOngoing
 179 {
 180 public:
 181         HTTPFetchOngoing(HTTPFetchRequest request, CurlHandlePool *pool);
 182         ~HTTPFetchOngoing();
 183
 184         CURLcode start(CURLM *multi);
 185         const HTTPFetchResult * complete(CURLcode res);
 186
 187         const HTTPFetchRequest &getRequest()    const { return request; };
 188         const CURL             *getEasyHandle() const { return curl; };
 189
 190 private:
 191         CurlHandlePool *pool;
 192         CURL *curl;
 193         CURLM *multi;
 194         HTTPFetchRequest request;
 195         HTTPFetchResult result;
 196         std::ostringstream oss;
 197         char *post_fields;
 198         struct curl_slist *http_header;
 199         curl_httppost *post;
 200 };
 201
 202
 203 HTTPFetchOngoing::HTTPFetchOngoing(HTTPFetchRequest request_, CurlHandlePool *pool_):
 204         pool(pool_),
 205         curl(NULL),
 206         multi(NULL),
 207         request(request_),
 208         result(request_),
 209         oss(std::ios::binary),
 210         http_header(NULL),
 211         post(NULL)
 212 {
 213         curl = pool->alloc();
 214         if (curl == NULL) {
 215                 return;
 216         }
 217
 218         // Set static cURL options
 219         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 220         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 221         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 222         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 1);
 223
 224 #if LIBCURL_VERSION_NUM >= 0x071304
 225         // Restrict protocols so that curl vulnerabilities in
 226         // other protocols don't affect us.
 227         // These settings were introduced in curl 7.19.4.
 228         long protocols =
 229                 CURLPROTO_HTTP |
 230                 CURLPROTO_HTTPS |
 231                 CURLPROTO_FTP |
 232                 CURLPROTO_FTPS;
 233         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 234         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 235 #endif
 236
 237         // Set cURL options based on HTTPFetchRequest
 238         curl_easy_setopt(curl, CURLOPT_URL,
 239                         request.url.c_str());
 240         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 241                         request.timeout);
 242         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 243                         request.connect_timeout);
 244
 245         if (request.useragent != "")
 246                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 247
 248         // Set up a write callback that writes to the
 249         // ostringstream ongoing->oss, unless the data
 250         // is to be discarded
 251         if (request.caller == HTTPFETCH_DISCARD) {
 252                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 253                                 httpfetch_discardfunction);
 254                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 255         } else {
 256                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 257                                 httpfetch_writefunction);
 258                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 259         }
 260
 261         // Set POST (or GET) data
 262         if (request.post_fields.empty()) {
 263                 curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 264         } else if (request.multipart) {
 265                 curl_httppost *last = NULL;
 266                 for (std::map<std::string, std::string>::iterator it =
 267                                         request.post_fields.begin();
 268                                 it != request.post_fields.end(); ++it) {
 269                         curl_formadd(&post, &last,
 270                                         CURLFORM_NAMELENGTH, it->first.size(),
 271                                         CURLFORM_PTRNAME, it->first.c_str(),
 272                                         CURLFORM_CONTENTSLENGTH, it->second.size(),
 273                                         CURLFORM_PTRCONTENTS, it->second.c_str(),
 274                                         CURLFORM_END);
 275                 }
 276                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
 277                 // request.post_fields must now *never* be
 278                 // modified until CURLOPT_HTTPPOST is cleared
 279         } else if (request.post_data.empty()) {
 280                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 281                 std::string str;
 282                 for (std::map<std::string, std::string>::iterator it =
 283                                         request.post_fields.begin();
 284                                 it != request.post_fields.end();
 285                                 ++it) {
 286                         if (str != "")
 287                                 str += "&";
 288                         str += urlencode(it->first);
 289                         str += "=";
 290                         str += urlencode(it->second);
 291                 }
 292                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 293                                 str.size());
 294                 curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
 295                                 str.c_str());
 296         } else {
 297                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 298                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 299                                 request.post_data.size());
 300                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 301                                 request.post_data.c_str());
 302                 // request.post_data must now *never* be
 303                 // modified until CURLOPT_POSTFIELDS is cleared
 304         }
 305         // Set additional HTTP headers
 306         for (std::vector<std::string>::iterator it = request.extra_headers.begin();
 307                         it != request.extra_headers.end(); ++it) {
 308                 http_header = curl_slist_append(http_header, it->c_str());
 309         }
 310         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, http_header);
 311
 312         if (!g_settings->getBool("curl_verify_cert")) {
 313                 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
 314         }
 315 }
 316
 317 CURLcode HTTPFetchOngoing::start(CURLM *multi_)
 318 {
 319         if (!curl)
 320                 return CURLE_FAILED_INIT;
 321
 322         if (!multi_) {
 323                 // Easy interface (sync)
 324                 return curl_easy_perform(curl);
 325         }
 326
 327         // Multi interface (async)
 328         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 329         if (mres != CURLM_OK) {
 330                 errorstream << "curl_multi_add_handle"
 331                         << " returned error code " << mres
 332                         << std::endl;
 333                 return CURLE_FAILED_INIT;
 334         }
 335         multi = multi_; // store for curl_multi_remove_handle
 336         return CURLE_OK;
 337 }
 338
 339 const HTTPFetchResult * HTTPFetchOngoing::complete(CURLcode res)
 340 {
 341         result.succeeded = (res == CURLE_OK);
 342         result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 343         result.data = oss.str();
 344
 345         // Get HTTP/FTP response code
 346         result.response_code = 0;
 347         if (curl && (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 348                                 &result.response_code) != CURLE_OK)) {
 349                 // We failed to get a return code, make sure it is still 0
 350                 result.response_code = 0;
 351         }
 352
 353         if (res != CURLE_OK) {
 354                 errorstream << request.url << " not found ("
 355                         << curl_easy_strerror(res) << ")"
 356                         << " (response code " << result.response_code << ")"
 357                         << std::endl;
 358         }
 359
 360         return &result;
 361 }
 362
 363 HTTPFetchOngoing::~HTTPFetchOngoing()
 364 {
 365         if (multi) {
 366                 CURLMcode mres = curl_multi_remove_handle(multi, curl);
 367                 if (mres != CURLM_OK) {
 368                         errorstream << "curl_multi_remove_handle"
 369                                 << " returned error code " << mres
 370                                 << std::endl;
 371                 }
 372         }
 373
 374         // Set safe options for the reusable cURL handle
 375         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 376                         httpfetch_discardfunction);
 377         curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 378         curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 379         if (http_header) {
 380                 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 381                 curl_slist_free_all(http_header);
 382         }
 383         if (post) {
 384                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
 385                 curl_formfree(post);
 386         }
 387
 388         // Store the cURL handle for reuse
 389         pool->free(curl);
 390 }
 391
 392
 393 class CurlFetchThread : public JThread
 394 {
 395 protected:
 396         enum RequestType {
 397                 RT_FETCH,
 398                 RT_CLEAR,
 399                 RT_WAKEUP,
 400         };
 401
 402         struct Request {
 403                 RequestType type;
 404                 HTTPFetchRequest fetch_request;
 405                 Event *event;
 406         };
 407
 408         CURLM *m_multi;
 409         MutexedQueue<Request> m_requests;
 410         size_t m_parallel_limit;
 411
 412         // Variables exclusively used within thread
 413         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 414         std::list<HTTPFetchRequest> m_queued_fetches;
 415
 416 public:
 417         CurlFetchThread(int parallel_limit)
 418         {
 419                 if (parallel_limit >= 1)
 420                         m_parallel_limit = parallel_limit;
 421                 else
 422                         m_parallel_limit = 1;
 423         }
 424
 425         void requestFetch(const HTTPFetchRequest &fetch_request)
 426         {
 427                 Request req;
 428                 req.type = RT_FETCH;
 429                 req.fetch_request = fetch_request;
 430                 req.event = NULL;
 431                 m_requests.push_back(req);
 432         }
 433
 434         void requestClear(unsigned long caller, Event *event)
 435         {
 436                 Request req;
 437                 req.type = RT_CLEAR;
 438                 req.fetch_request.caller = caller;
 439                 req.event = event;
 440                 m_requests.push_back(req);
 441         }
 442
 443         void requestWakeUp()
 444         {
 445                 Request req;
 446                 req.type = RT_WAKEUP;
 447                 req.event = NULL;
 448                 m_requests.push_back(req);
 449         }
 450
 451 protected:
 452         // Handle a request from some other thread
 453         // E.g. new fetch; clear fetches for one caller; wake up
 454         void processRequest(const Request &req)
 455         {
 456                 if (req.type == RT_FETCH) {
 457                         // New fetch, queue until there are less
 458                         // than m_parallel_limit ongoing fetches
 459                         m_queued_fetches.push_back(req.fetch_request);
 460
 461                         // see processQueued() for what happens next
 462
 463                 }
 464                 else if (req.type == RT_CLEAR) {
 465                         unsigned long caller = req.fetch_request.caller;
 466
 467                         // Abort all ongoing fetches for the caller
 468                         for (std::vector<HTTPFetchOngoing*>::iterator
 469                                         it = m_all_ongoing.begin();
 470                                         it != m_all_ongoing.end();) {
 471                                 if ((*it)->getRequest().caller == caller) {
 472                                         delete (*it);
 473                                         it = m_all_ongoing.erase(it);
 474                                 } else {
 475                                         ++it;
 476                                 }
 477                         }
 478
 479                         // Also abort all queued fetches for the caller
 480                         for (std::list<HTTPFetchRequest>::iterator
 481                                         it = m_queued_fetches.begin();
 482                                         it != m_queued_fetches.end();) {
 483                                 if ((*it).caller == caller)
 484                                         it = m_queued_fetches.erase(it);
 485                                 else
 486                                         ++it;
 487                         }
 488                 }
 489                 else if (req.type == RT_WAKEUP) {
 490                         // Wakeup: Nothing to do, thread is awake at this point
 491                 }
 492
 493                 if (req.event != NULL)
 494                         req.event->signal();
 495         }
 496
 497         // Start new ongoing fetches if m_parallel_limit allows
 498         void processQueued(CurlHandlePool *pool)
 499         {
 500                 while (m_all_ongoing.size() < m_parallel_limit &&
 501                                 !m_queued_fetches.empty()) {
 502                         HTTPFetchRequest request = m_queued_fetches.front();
 503                         m_queued_fetches.pop_front();
 504
 505                         // Create ongoing fetch data and make a cURL handle
 506                         // Set cURL options based on HTTPFetchRequest
 507                         HTTPFetchOngoing *ongoing =
 508                                 new HTTPFetchOngoing(request, pool);
 509
 510                         // Initiate the connection (curl_multi_add_handle)
 511                         CURLcode res = ongoing->start(m_multi);
 512                         if (res == CURLE_OK) {
 513                                 m_all_ongoing.push_back(ongoing);
 514                         }
 515                         else {
 516                                 httpfetch_deliver_result(*ongoing->complete(res));
 517                                 delete ongoing;
 518                         }
 519                 }
 520         }
 521
 522         // Process CURLMsg (indicates completion of a fetch)
 523         void processCurlMessage(CURLMsg *msg)
 524         {
 525                 // Determine which ongoing fetch the message pertains to
 526                 size_t i = 0;
 527                 bool found = false;
 528                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 529                         if (m_all_ongoing[i]->getEasyHandle() == msg->easy_handle) {
 530                                 found = true;
 531                                 break;
 532                         }
 533                 }
 534                 if (msg->msg == CURLMSG_DONE && found) {
 535                         // m_all_ongoing[i] succeeded or failed.
 536                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 537                         httpfetch_deliver_result(*ongoing->complete(msg->data.result));
 538                         delete ongoing;
 539                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 540                 }
 541         }
 542
 543         // Wait for a request from another thread, or timeout elapses
 544         void waitForRequest(long timeout)
 545         {
 546                 if (m_queued_fetches.empty()) {
 547                         try {
 548                                 Request req = m_requests.pop_front(timeout);
 549                                 processRequest(req);
 550                         }
 551                         catch (ItemNotFoundException &e) {}
 552                 }
 553         }
 554
 555         // Wait until some IO happens, or timeout elapses
 556         void waitForIO(long timeout)
 557         {
 558                 fd_set read_fd_set;
 559                 fd_set write_fd_set;
 560                 fd_set exc_fd_set;
 561                 int max_fd;
 562                 long select_timeout = -1;
 563                 struct timeval select_tv;
 564                 CURLMcode mres;
 565
 566                 FD_ZERO(&read_fd_set);
 567                 FD_ZERO(&write_fd_set);
 568                 FD_ZERO(&exc_fd_set);
 569
 570                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 571                                 &write_fd_set, &exc_fd_set, &max_fd);
 572                 if (mres != CURLM_OK) {
 573                         errorstream<<"curl_multi_fdset"
 574                                 <<" returned error code "<<mres
 575                                 <<std::endl;
 576                         select_timeout = 0;
 577                 }
 578
 579                 mres = curl_multi_timeout(m_multi, &select_timeout);
 580                 if (mres != CURLM_OK) {
 581                         errorstream<<"curl_multi_timeout"
 582                                 <<" returned error code "<<mres
 583                                 <<std::endl;
 584                         select_timeout = 0;
 585                 }
 586
 587                 // Limit timeout so new requests get through
 588                 if (select_timeout < 0 || select_timeout > timeout)
 589                         select_timeout = timeout;
 590
 591                 if (select_timeout > 0) {
 592                         // in Winsock it is forbidden to pass three empty
 593                         // fd_sets to select(), so in that case use sleep_ms
 594                         if (max_fd != -1) {
 595                                 select_tv.tv_sec = select_timeout / 1000;
 596                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 597                                 int retval = select(max_fd + 1, &read_fd_set,
 598                                                 &write_fd_set, &exc_fd_set,
 599                                                 &select_tv);
 600                                 if (retval == -1) {
 601                                         #ifdef _WIN32
 602                                         errorstream<<"select returned error code "
 603                                                 <<WSAGetLastError()<<std::endl;
 604                                         #else
 605                                         errorstream<<"select returned error code "
 606                                                 <<errno<<std::endl;
 607                                         #endif
 608                                 }
 609                         }
 610                         else {
 611                                 sleep_ms(select_timeout);
 612                         }
 613                 }
 614         }
 615
 616         void * Thread()
 617         {
 618                 ThreadStarted();
 619                 log_register_thread("CurlFetchThread");
 620                 DSTACK(__FUNCTION_NAME);
 621
 622                 porting::setThreadName("CurlFetchThread");
 623
 624                 CurlHandlePool pool;
 625
 626                 m_multi = curl_multi_init();
 627                 if (m_multi == NULL) {
 628                         errorstream<<"curl_multi_init returned NULL\n";
 629                         return NULL;
 630                 }
 631
 632                 assert(m_all_ongoing.empty());
 633
 634                 while (!StopRequested()) {
 635                         BEGIN_DEBUG_EXCEPTION_HANDLER
 636
 637                         /*
 638                                 Handle new async requests
 639                         */
 640
 641                         while (!m_requests.empty()) {
 642                                 Request req = m_requests.pop_frontNoEx();
 643                                 processRequest(req);
 644                         }
 645                         processQueued(&pool);
 646
 647                         /*
 648                                 Handle ongoing async requests
 649                         */
 650
 651                         int still_ongoing = 0;
 652                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 653                                         CURLM_CALL_MULTI_PERFORM)
 654                                 /* noop */;
 655
 656                         /*
 657                                 Handle completed async requests
 658                         */
 659                         if (still_ongoing < (int) m_all_ongoing.size()) {
 660                                 CURLMsg *msg;
 661                                 int msgs_in_queue;
 662                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 663                                 while (msg != NULL) {
 664                                         processCurlMessage(msg);
 665                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 666                                 }
 667                         }
 668
 669                         /*
 670                                 If there are ongoing requests, wait for data
 671                                 (with a timeout of 100ms so that new requests
 672                                 can be processed).
 673
 674                                 If no ongoing requests, wait for a new request.
 675                                 (Possibly an empty request that signals
 676                                 that the thread should be stopped.)
 677                         */
 678                         if (m_all_ongoing.empty())
 679                                 waitForRequest(100000000);
 680                         else
 681                                 waitForIO(100);
 682
 683                         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 684                 }
 685
 686                 // Call curl_multi_remove_handle and cleanup easy handles
 687                 for (size_t i = 0; i < m_all_ongoing.size(); ++i) {
 688                         delete m_all_ongoing[i];
 689                 }
 690                 m_all_ongoing.clear();
 691
 692                 m_queued_fetches.clear();
 693
 694                 CURLMcode mres = curl_multi_cleanup(m_multi);
 695                 if (mres != CURLM_OK) {
 696                         errorstream<<"curl_multi_cleanup"
 697                                 <<" returned error code "<<mres
 698                                 <<std::endl;
 699                 }
 700
 701                 return NULL;
 702         }
 703 };
 704
 705 CurlFetchThread *g_httpfetch_thread = NULL;
 706
 707 void httpfetch_init(int parallel_limit)
 708 {
 709         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 710                         <<std::endl;
 711
 712         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 713         assert(res == CURLE_OK);
 714
 715         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 716 }
 717
 718 void httpfetch_cleanup()
 719 {
 720         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 721
 722         g_httpfetch_thread->Stop();
 723         g_httpfetch_thread->requestWakeUp();
 724         g_httpfetch_thread->Wait();
 725         delete g_httpfetch_thread;
 726
 727         curl_global_cleanup();
 728 }
 729
 730 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 731 {
 732         g_httpfetch_thread->requestFetch(fetch_request);
 733         if (!g_httpfetch_thread->IsRunning())
 734                 g_httpfetch_thread->Start();
 735 }
 736
 737 static void httpfetch_request_clear(unsigned long caller)
 738 {
 739         if (g_httpfetch_thread->IsRunning()) {
 740                 Event event;
 741                 g_httpfetch_thread->requestClear(caller, &event);
 742                 event.wait();
 743         }
 744         else {
 745                 g_httpfetch_thread->requestClear(caller, NULL);
 746         }
 747 }
 748
 749 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 750                 HTTPFetchResult &fetch_result)
 751 {
 752         // Create ongoing fetch data and make a cURL handle
 753         // Set cURL options based on HTTPFetchRequest
 754         CurlHandlePool pool;
 755         HTTPFetchOngoing ongoing(fetch_request, &pool);
 756         // Do the fetch (curl_easy_perform)
 757         CURLcode res = ongoing.start(NULL);
 758         // Update fetch result
 759         fetch_result = *ongoing.complete(res);
 760 }
 761
 762 #else  // USE_CURL
 763
 764 /*
 765         USE_CURL is off:
 766
 767         Dummy httpfetch implementation that always returns an error.
 768 */
 769
 770 void httpfetch_init(int parallel_limit)
 771 {
 772 }
 773
 774 void httpfetch_cleanup()
 775 {
 776 }
 777
 778 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 779 {
 780         errorstream << "httpfetch_async: unable to fetch " << fetch_request.url
 781                         << " because USE_CURL=0" << std::endl;
 782
 783         HTTPFetchResult fetch_result(fetch_request); // sets succeeded = false etc.
 784         httpfetch_deliver_result(fetch_result);
 785 }
 786
 787 static void httpfetch_request_clear(unsigned long caller)
 788 {
 789 }
 790
 791 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 792                 HTTPFetchResult &fetch_result)
 793 {
 794         errorstream << "httpfetch_sync: unable to fetch " << fetch_request.url
 795                         << " because USE_CURL=0" << std::endl;
 796
 797         fetch_result = HTTPFetchResult(fetch_request); // sets succeeded = false etc.
 798 }
 799
 800 #endif  // USE_CURL