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 "settings.h"
  37
  38 JMutex g_httpfetch_mutex;
  39 std::map<unsigned long, std::queue<HTTPFetchResult> > g_httpfetch_results;
  40
  41 HTTPFetchRequest::HTTPFetchRequest()
  42 {
  43         url = "";
  44         caller = HTTPFETCH_DISCARD;
  45         request_id = 0;
  46         timeout = g_settings->getS32("curl_timeout");
  47         connect_timeout = timeout;
  48         multipart = false;
  49
  50         useragent = std::string(PROJECT_NAME "/") + g_version_hash + " (" + porting::get_sysinfo() + ")";
  51 }
  52
  53
  54 static void httpfetch_deliver_result(const HTTPFetchResult &fetch_result)
  55 {
  56         unsigned long caller = fetch_result.caller;
  57         if (caller != HTTPFETCH_DISCARD) {
  58                 JMutexAutoLock lock(g_httpfetch_mutex);
  59                 g_httpfetch_results[caller].push(fetch_result);
  60         }
  61 }
  62
  63 static void httpfetch_request_clear(unsigned long caller);
  64
  65 unsigned long httpfetch_caller_alloc()
  66 {
  67         JMutexAutoLock lock(g_httpfetch_mutex);
  68
  69         // Check each caller ID except HTTPFETCH_DISCARD
  70         const unsigned long discard = HTTPFETCH_DISCARD;
  71         for (unsigned long caller = discard + 1; caller != discard; ++caller) {
  72                 std::map<unsigned long, std::queue<HTTPFetchResult> >::iterator
  73                         it = g_httpfetch_results.find(caller);
  74                 if (it == g_httpfetch_results.end()) {
  75                         verbosestream << "httpfetch_caller_alloc: allocating "
  76                                         << caller << std::endl;
  77                         // Access element to create it
  78                         g_httpfetch_results[caller];
  79                         return caller;
  80                 }
  81         }
  82
  83         FATAL_ERROR("httpfetch_caller_alloc: ran out of caller IDs");
  84         return discard;
  85 }
  86
  87 void httpfetch_caller_free(unsigned long caller)
  88 {
  89         verbosestream<<"httpfetch_caller_free: freeing "
  90                         <<caller<<std::endl;
  91
  92         httpfetch_request_clear(caller);
  93         if (caller != HTTPFETCH_DISCARD) {
  94                 JMutexAutoLock lock(g_httpfetch_mutex);
  95                 g_httpfetch_results.erase(caller);
  96         }
  97 }
  98
  99 bool httpfetch_async_get(unsigned long caller, HTTPFetchResult &fetch_result)
 100 {
 101         JMutexAutoLock lock(g_httpfetch_mutex);
 102
 103         // Check that caller exists
 104         std::map<unsigned long, std::queue<HTTPFetchResult> >::iterator
 105                 it = g_httpfetch_results.find(caller);
 106         if (it == g_httpfetch_results.end())
 107                 return false;
 108
 109         // Check that result queue is nonempty
 110         std::queue<HTTPFetchResult> &caller_results = it->second;
 111         if (caller_results.empty())
 112                 return false;
 113
 114         // Pop first result
 115         fetch_result = caller_results.front();
 116         caller_results.pop();
 117         return true;
 118 }
 119
 120 #if USE_CURL
 121 #include <curl/curl.h>
 122
 123 /*
 124         USE_CURL is on: use cURL based httpfetch implementation
 125 */
 126
 127 static size_t httpfetch_writefunction(
 128                 char *ptr, size_t size, size_t nmemb, void *userdata)
 129 {
 130         std::ostringstream *stream = (std::ostringstream*)userdata;
 131         size_t count = size * nmemb;
 132         stream->write(ptr, count);
 133         return count;
 134 }
 135
 136 static size_t httpfetch_discardfunction(
 137                 char *ptr, size_t size, size_t nmemb, void *userdata)
 138 {
 139         return size * nmemb;
 140 }
 141
 142 class CurlHandlePool
 143 {
 144         std::list<CURL*> handles;
 145
 146 public:
 147         CurlHandlePool() {}
 148         ~CurlHandlePool()
 149         {
 150                 for (std::list<CURL*>::iterator it = handles.begin();
 151                                 it != handles.end(); ++it) {
 152                         curl_easy_cleanup(*it);
 153                 }
 154         }
 155         CURL * alloc()
 156         {
 157                 CURL *curl;
 158                 if (handles.empty()) {
 159                         curl = curl_easy_init();
 160                         if (curl == NULL) {
 161                                 errorstream<<"curl_easy_init returned NULL"<<std::endl;
 162                         }
 163                 }
 164                 else {
 165                         curl = handles.front();
 166                         handles.pop_front();
 167                 }
 168                 return curl;
 169         }
 170         void free(CURL *handle)
 171         {
 172                 if (handle)
 173                         handles.push_back(handle);
 174         }
 175 };
 176
 177 class HTTPFetchOngoing
 178 {
 179 public:
 180         HTTPFetchOngoing(HTTPFetchRequest request, CurlHandlePool *pool);
 181         ~HTTPFetchOngoing();
 182
 183         CURLcode start(CURLM *multi);
 184         const HTTPFetchResult * complete(CURLcode res);
 185
 186         const HTTPFetchRequest &getRequest()    const { return request; };
 187         const CURL             *getEasyHandle() const { return curl; };
 188
 189 private:
 190         CurlHandlePool *pool;
 191         CURL *curl;
 192         CURLM *multi;
 193         HTTPFetchRequest request;
 194         HTTPFetchResult result;
 195         std::ostringstream oss;
 196         struct curl_slist *http_header;
 197         curl_httppost *post;
 198 };
 199
 200
 201 HTTPFetchOngoing::HTTPFetchOngoing(HTTPFetchRequest request_, CurlHandlePool *pool_):
 202         pool(pool_),
 203         curl(NULL),
 204         multi(NULL),
 205         request(request_),
 206         result(request_),
 207         oss(std::ios::binary),
 208         http_header(NULL),
 209         post(NULL)
 210 {
 211         curl = pool->alloc();
 212         if (curl == NULL) {
 213                 return;
 214         }
 215
 216         // Set static cURL options
 217         curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
 218         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 219         curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
 220         curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 1);
 221
 222         std::string bind_address = g_settings->get("bind_address");
 223         if (!bind_address.empty()) {
 224                 curl_easy_setopt(curl, CURLOPT_INTERFACE, bind_address.c_str());
 225         }
 226
 227 #if LIBCURL_VERSION_NUM >= 0x071304
 228         // Restrict protocols so that curl vulnerabilities in
 229         // other protocols don't affect us.
 230         // These settings were introduced in curl 7.19.4.
 231         long protocols =
 232                 CURLPROTO_HTTP |
 233                 CURLPROTO_HTTPS |
 234                 CURLPROTO_FTP |
 235                 CURLPROTO_FTPS;
 236         curl_easy_setopt(curl, CURLOPT_PROTOCOLS, protocols);
 237         curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS, protocols);
 238 #endif
 239
 240         // Set cURL options based on HTTPFetchRequest
 241         curl_easy_setopt(curl, CURLOPT_URL,
 242                         request.url.c_str());
 243         curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS,
 244                         request.timeout);
 245         curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,
 246                         request.connect_timeout);
 247
 248         if (request.useragent != "")
 249                 curl_easy_setopt(curl, CURLOPT_USERAGENT, request.useragent.c_str());
 250
 251         // Set up a write callback that writes to the
 252         // ostringstream ongoing->oss, unless the data
 253         // is to be discarded
 254         if (request.caller == HTTPFETCH_DISCARD) {
 255                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 256                                 httpfetch_discardfunction);
 257                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 258         } else {
 259                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 260                                 httpfetch_writefunction);
 261                 curl_easy_setopt(curl, CURLOPT_WRITEDATA, &oss);
 262         }
 263
 264         // Set POST (or GET) data
 265         if (request.post_fields.empty()) {
 266                 curl_easy_setopt(curl, CURLOPT_HTTPGET, 1);
 267         } else if (request.multipart) {
 268                 curl_httppost *last = NULL;
 269                 for (std::map<std::string, std::string>::iterator it =
 270                                         request.post_fields.begin();
 271                                 it != request.post_fields.end(); ++it) {
 272                         curl_formadd(&post, &last,
 273                                         CURLFORM_NAMELENGTH, it->first.size(),
 274                                         CURLFORM_PTRNAME, it->first.c_str(),
 275                                         CURLFORM_CONTENTSLENGTH, it->second.size(),
 276                                         CURLFORM_PTRCONTENTS, it->second.c_str(),
 277                                         CURLFORM_END);
 278                 }
 279                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, post);
 280                 // request.post_fields must now *never* be
 281                 // modified until CURLOPT_HTTPPOST is cleared
 282         } else if (request.post_data.empty()) {
 283                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 284                 std::string str;
 285                 for (std::map<std::string, std::string>::iterator it =
 286                                         request.post_fields.begin();
 287                                 it != request.post_fields.end();
 288                                 ++it) {
 289                         if (str != "")
 290                                 str += "&";
 291                         str += urlencode(it->first);
 292                         str += "=";
 293                         str += urlencode(it->second);
 294                 }
 295                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 296                                 str.size());
 297                 curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS,
 298                                 str.c_str());
 299         } else {
 300                 curl_easy_setopt(curl, CURLOPT_POST, 1);
 301                 curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE,
 302                                 request.post_data.size());
 303                 curl_easy_setopt(curl, CURLOPT_POSTFIELDS,
 304                                 request.post_data.c_str());
 305                 // request.post_data must now *never* be
 306                 // modified until CURLOPT_POSTFIELDS is cleared
 307         }
 308         // Set additional HTTP headers
 309         for (std::vector<std::string>::iterator it = request.extra_headers.begin();
 310                         it != request.extra_headers.end(); ++it) {
 311                 http_header = curl_slist_append(http_header, it->c_str());
 312         }
 313         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, http_header);
 314
 315         if (!g_settings->getBool("curl_verify_cert")) {
 316                 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false);
 317         }
 318 }
 319
 320 CURLcode HTTPFetchOngoing::start(CURLM *multi_)
 321 {
 322         if (!curl)
 323                 return CURLE_FAILED_INIT;
 324
 325         if (!multi_) {
 326                 // Easy interface (sync)
 327                 return curl_easy_perform(curl);
 328         }
 329
 330         // Multi interface (async)
 331         CURLMcode mres = curl_multi_add_handle(multi_, curl);
 332         if (mres != CURLM_OK) {
 333                 errorstream << "curl_multi_add_handle"
 334                         << " returned error code " << mres
 335                         << std::endl;
 336                 return CURLE_FAILED_INIT;
 337         }
 338         multi = multi_; // store for curl_multi_remove_handle
 339         return CURLE_OK;
 340 }
 341
 342 const HTTPFetchResult * HTTPFetchOngoing::complete(CURLcode res)
 343 {
 344         result.succeeded = (res == CURLE_OK);
 345         result.timeout = (res == CURLE_OPERATION_TIMEDOUT);
 346         result.data = oss.str();
 347
 348         // Get HTTP/FTP response code
 349         result.response_code = 0;
 350         if (curl && (curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE,
 351                                 &result.response_code) != CURLE_OK)) {
 352                 // We failed to get a return code, make sure it is still 0
 353                 result.response_code = 0;
 354         }
 355
 356         if (res != CURLE_OK) {
 357                 errorstream << request.url << " not found ("
 358                         << curl_easy_strerror(res) << ")"
 359                         << " (response code " << result.response_code << ")"
 360                         << std::endl;
 361         }
 362
 363         return &result;
 364 }
 365
 366 HTTPFetchOngoing::~HTTPFetchOngoing()
 367 {
 368         if (multi) {
 369                 CURLMcode mres = curl_multi_remove_handle(multi, curl);
 370                 if (mres != CURLM_OK) {
 371                         errorstream << "curl_multi_remove_handle"
 372                                 << " returned error code " << mres
 373                                 << std::endl;
 374                 }
 375         }
 376
 377         // Set safe options for the reusable cURL handle
 378         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
 379                         httpfetch_discardfunction);
 380         curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
 381         curl_easy_setopt(curl, CURLOPT_POSTFIELDS, NULL);
 382         if (http_header) {
 383                 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
 384                 curl_slist_free_all(http_header);
 385         }
 386         if (post) {
 387                 curl_easy_setopt(curl, CURLOPT_HTTPPOST, NULL);
 388                 curl_formfree(post);
 389         }
 390
 391         // Store the cURL handle for reuse
 392         pool->free(curl);
 393 }
 394
 395
 396 class CurlFetchThread : public JThread
 397 {
 398 protected:
 399         enum RequestType {
 400                 RT_FETCH,
 401                 RT_CLEAR,
 402                 RT_WAKEUP,
 403         };
 404
 405         struct Request {
 406                 RequestType type;
 407                 HTTPFetchRequest fetch_request;
 408                 Event *event;
 409         };
 410
 411         CURLM *m_multi;
 412         MutexedQueue<Request> m_requests;
 413         size_t m_parallel_limit;
 414
 415         // Variables exclusively used within thread
 416         std::vector<HTTPFetchOngoing*> m_all_ongoing;
 417         std::list<HTTPFetchRequest> m_queued_fetches;
 418
 419 public:
 420         CurlFetchThread(int parallel_limit)
 421         {
 422                 if (parallel_limit >= 1)
 423                         m_parallel_limit = parallel_limit;
 424                 else
 425                         m_parallel_limit = 1;
 426         }
 427
 428         void requestFetch(const HTTPFetchRequest &fetch_request)
 429         {
 430                 Request req;
 431                 req.type = RT_FETCH;
 432                 req.fetch_request = fetch_request;
 433                 req.event = NULL;
 434                 m_requests.push_back(req);
 435         }
 436
 437         void requestClear(unsigned long caller, Event *event)
 438         {
 439                 Request req;
 440                 req.type = RT_CLEAR;
 441                 req.fetch_request.caller = caller;
 442                 req.event = event;
 443                 m_requests.push_back(req);
 444         }
 445
 446         void requestWakeUp()
 447         {
 448                 Request req;
 449                 req.type = RT_WAKEUP;
 450                 req.event = NULL;
 451                 m_requests.push_back(req);
 452         }
 453
 454 protected:
 455         // Handle a request from some other thread
 456         // E.g. new fetch; clear fetches for one caller; wake up
 457         void processRequest(const Request &req)
 458         {
 459                 if (req.type == RT_FETCH) {
 460                         // New fetch, queue until there are less
 461                         // than m_parallel_limit ongoing fetches
 462                         m_queued_fetches.push_back(req.fetch_request);
 463
 464                         // see processQueued() for what happens next
 465
 466                 }
 467                 else if (req.type == RT_CLEAR) {
 468                         unsigned long caller = req.fetch_request.caller;
 469
 470                         // Abort all ongoing fetches for the caller
 471                         for (std::vector<HTTPFetchOngoing*>::iterator
 472                                         it = m_all_ongoing.begin();
 473                                         it != m_all_ongoing.end();) {
 474                                 if ((*it)->getRequest().caller == caller) {
 475                                         delete (*it);
 476                                         it = m_all_ongoing.erase(it);
 477                                 } else {
 478                                         ++it;
 479                                 }
 480                         }
 481
 482                         // Also abort all queued fetches for the caller
 483                         for (std::list<HTTPFetchRequest>::iterator
 484                                         it = m_queued_fetches.begin();
 485                                         it != m_queued_fetches.end();) {
 486                                 if ((*it).caller == caller)
 487                                         it = m_queued_fetches.erase(it);
 488                                 else
 489                                         ++it;
 490                         }
 491                 }
 492                 else if (req.type == RT_WAKEUP) {
 493                         // Wakeup: Nothing to do, thread is awake at this point
 494                 }
 495
 496                 if (req.event != NULL)
 497                         req.event->signal();
 498         }
 499
 500         // Start new ongoing fetches if m_parallel_limit allows
 501         void processQueued(CurlHandlePool *pool)
 502         {
 503                 while (m_all_ongoing.size() < m_parallel_limit &&
 504                                 !m_queued_fetches.empty()) {
 505                         HTTPFetchRequest request = m_queued_fetches.front();
 506                         m_queued_fetches.pop_front();
 507
 508                         // Create ongoing fetch data and make a cURL handle
 509                         // Set cURL options based on HTTPFetchRequest
 510                         HTTPFetchOngoing *ongoing =
 511                                 new HTTPFetchOngoing(request, pool);
 512
 513                         // Initiate the connection (curl_multi_add_handle)
 514                         CURLcode res = ongoing->start(m_multi);
 515                         if (res == CURLE_OK) {
 516                                 m_all_ongoing.push_back(ongoing);
 517                         }
 518                         else {
 519                                 httpfetch_deliver_result(*ongoing->complete(res));
 520                                 delete ongoing;
 521                         }
 522                 }
 523         }
 524
 525         // Process CURLMsg (indicates completion of a fetch)
 526         void processCurlMessage(CURLMsg *msg)
 527         {
 528                 // Determine which ongoing fetch the message pertains to
 529                 size_t i = 0;
 530                 bool found = false;
 531                 for (i = 0; i < m_all_ongoing.size(); ++i) {
 532                         if (m_all_ongoing[i]->getEasyHandle() == msg->easy_handle) {
 533                                 found = true;
 534                                 break;
 535                         }
 536                 }
 537                 if (msg->msg == CURLMSG_DONE && found) {
 538                         // m_all_ongoing[i] succeeded or failed.
 539                         HTTPFetchOngoing *ongoing = m_all_ongoing[i];
 540                         httpfetch_deliver_result(*ongoing->complete(msg->data.result));
 541                         delete ongoing;
 542                         m_all_ongoing.erase(m_all_ongoing.begin() + i);
 543                 }
 544         }
 545
 546         // Wait for a request from another thread, or timeout elapses
 547         void waitForRequest(long timeout)
 548         {
 549                 if (m_queued_fetches.empty()) {
 550                         try {
 551                                 Request req = m_requests.pop_front(timeout);
 552                                 processRequest(req);
 553                         }
 554                         catch (ItemNotFoundException &e) {}
 555                 }
 556         }
 557
 558         // Wait until some IO happens, or timeout elapses
 559         void waitForIO(long timeout)
 560         {
 561                 fd_set read_fd_set;
 562                 fd_set write_fd_set;
 563                 fd_set exc_fd_set;
 564                 int max_fd;
 565                 long select_timeout = -1;
 566                 struct timeval select_tv;
 567                 CURLMcode mres;
 568
 569                 FD_ZERO(&read_fd_set);
 570                 FD_ZERO(&write_fd_set);
 571                 FD_ZERO(&exc_fd_set);
 572
 573                 mres = curl_multi_fdset(m_multi, &read_fd_set,
 574                                 &write_fd_set, &exc_fd_set, &max_fd);
 575                 if (mres != CURLM_OK) {
 576                         errorstream<<"curl_multi_fdset"
 577                                 <<" returned error code "<<mres
 578                                 <<std::endl;
 579                         select_timeout = 0;
 580                 }
 581
 582                 mres = curl_multi_timeout(m_multi, &select_timeout);
 583                 if (mres != CURLM_OK) {
 584                         errorstream<<"curl_multi_timeout"
 585                                 <<" returned error code "<<mres
 586                                 <<std::endl;
 587                         select_timeout = 0;
 588                 }
 589
 590                 // Limit timeout so new requests get through
 591                 if (select_timeout < 0 || select_timeout > timeout)
 592                         select_timeout = timeout;
 593
 594                 if (select_timeout > 0) {
 595                         // in Winsock it is forbidden to pass three empty
 596                         // fd_sets to select(), so in that case use sleep_ms
 597                         if (max_fd != -1) {
 598                                 select_tv.tv_sec = select_timeout / 1000;
 599                                 select_tv.tv_usec = (select_timeout % 1000) * 1000;
 600                                 int retval = select(max_fd + 1, &read_fd_set,
 601                                                 &write_fd_set, &exc_fd_set,
 602                                                 &select_tv);
 603                                 if (retval == -1) {
 604                                         #ifdef _WIN32
 605                                         errorstream<<"select returned error code "
 606                                                 <<WSAGetLastError()<<std::endl;
 607                                         #else
 608                                         errorstream<<"select returned error code "
 609                                                 <<errno<<std::endl;
 610                                         #endif
 611                                 }
 612                         }
 613                         else {
 614                                 sleep_ms(select_timeout);
 615                         }
 616                 }
 617         }
 618
 619         void * Thread()
 620         {
 621                 ThreadStarted();
 622                 log_register_thread("CurlFetchThread");
 623                 DSTACK(__FUNCTION_NAME);
 624
 625                 porting::setThreadName("CurlFetchThread");
 626
 627                 CurlHandlePool pool;
 628
 629                 m_multi = curl_multi_init();
 630                 if (m_multi == NULL) {
 631                         errorstream<<"curl_multi_init returned NULL\n";
 632                         return NULL;
 633                 }
 634
 635                 FATAL_ERROR_IF(!m_all_ongoing.empty(), "Expected empty");
 636
 637                 while (!StopRequested()) {
 638                         BEGIN_DEBUG_EXCEPTION_HANDLER
 639
 640                         /*
 641                                 Handle new async requests
 642                         */
 643
 644                         while (!m_requests.empty()) {
 645                                 Request req = m_requests.pop_frontNoEx();
 646                                 processRequest(req);
 647                         }
 648                         processQueued(&pool);
 649
 650                         /*
 651                                 Handle ongoing async requests
 652                         */
 653
 654                         int still_ongoing = 0;
 655                         while (curl_multi_perform(m_multi, &still_ongoing) ==
 656                                         CURLM_CALL_MULTI_PERFORM)
 657                                 /* noop */;
 658
 659                         /*
 660                                 Handle completed async requests
 661                         */
 662                         if (still_ongoing < (int) m_all_ongoing.size()) {
 663                                 CURLMsg *msg;
 664                                 int msgs_in_queue;
 665                                 msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 666                                 while (msg != NULL) {
 667                                         processCurlMessage(msg);
 668                                         msg = curl_multi_info_read(m_multi, &msgs_in_queue);
 669                                 }
 670                         }
 671
 672                         /*
 673                                 If there are ongoing requests, wait for data
 674                                 (with a timeout of 100ms so that new requests
 675                                 can be processed).
 676
 677                                 If no ongoing requests, wait for a new request.
 678                                 (Possibly an empty request that signals
 679                                 that the thread should be stopped.)
 680                         */
 681                         if (m_all_ongoing.empty())
 682                                 waitForRequest(100000000);
 683                         else
 684                                 waitForIO(100);
 685
 686                         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 687                 }
 688
 689                 // Call curl_multi_remove_handle and cleanup easy handles
 690                 for (size_t i = 0; i < m_all_ongoing.size(); ++i) {
 691                         delete m_all_ongoing[i];
 692                 }
 693                 m_all_ongoing.clear();
 694
 695                 m_queued_fetches.clear();
 696
 697                 CURLMcode mres = curl_multi_cleanup(m_multi);
 698                 if (mres != CURLM_OK) {
 699                         errorstream<<"curl_multi_cleanup"
 700                                 <<" returned error code "<<mres
 701                                 <<std::endl;
 702                 }
 703
 704                 return NULL;
 705         }
 706 };
 707
 708 CurlFetchThread *g_httpfetch_thread = NULL;
 709
 710 void httpfetch_init(int parallel_limit)
 711 {
 712         verbosestream<<"httpfetch_init: parallel_limit="<<parallel_limit
 713                         <<std::endl;
 714
 715         CURLcode res = curl_global_init(CURL_GLOBAL_DEFAULT);
 716         FATAL_ERROR_IF(res != CURLE_OK, "CURL init failed");
 717
 718         g_httpfetch_thread = new CurlFetchThread(parallel_limit);
 719 }
 720
 721 void httpfetch_cleanup()
 722 {
 723         verbosestream<<"httpfetch_cleanup: cleaning up"<<std::endl;
 724
 725         g_httpfetch_thread->Stop();
 726         g_httpfetch_thread->requestWakeUp();
 727         g_httpfetch_thread->Wait();
 728         delete g_httpfetch_thread;
 729
 730         curl_global_cleanup();
 731 }
 732
 733 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 734 {
 735         g_httpfetch_thread->requestFetch(fetch_request);
 736         if (!g_httpfetch_thread->IsRunning())
 737                 g_httpfetch_thread->Start();
 738 }
 739
 740 static void httpfetch_request_clear(unsigned long caller)
 741 {
 742         if (g_httpfetch_thread->IsRunning()) {
 743                 Event event;
 744                 g_httpfetch_thread->requestClear(caller, &event);
 745                 event.wait();
 746         }
 747         else {
 748                 g_httpfetch_thread->requestClear(caller, NULL);
 749         }
 750 }
 751
 752 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 753                 HTTPFetchResult &fetch_result)
 754 {
 755         // Create ongoing fetch data and make a cURL handle
 756         // Set cURL options based on HTTPFetchRequest
 757         CurlHandlePool pool;
 758         HTTPFetchOngoing ongoing(fetch_request, &pool);
 759         // Do the fetch (curl_easy_perform)
 760         CURLcode res = ongoing.start(NULL);
 761         // Update fetch result
 762         fetch_result = *ongoing.complete(res);
 763 }
 764
 765 #else  // USE_CURL
 766
 767 /*
 768         USE_CURL is off:
 769
 770         Dummy httpfetch implementation that always returns an error.
 771 */
 772
 773 void httpfetch_init(int parallel_limit)
 774 {
 775 }
 776
 777 void httpfetch_cleanup()
 778 {
 779 }
 780
 781 void httpfetch_async(const HTTPFetchRequest &fetch_request)
 782 {
 783         errorstream << "httpfetch_async: unable to fetch " << fetch_request.url
 784                         << " because USE_CURL=0" << std::endl;
 785
 786         HTTPFetchResult fetch_result(fetch_request); // sets succeeded = false etc.
 787         httpfetch_deliver_result(fetch_result);
 788 }
 789
 790 static void httpfetch_request_clear(unsigned long caller)
 791 {
 792 }
 793
 794 void httpfetch_sync(const HTTPFetchRequest &fetch_request,
 795                 HTTPFetchResult &fetch_result)
 796 {
 797         errorstream << "httpfetch_sync: unable to fetch " << fetch_request.url
 798                         << " because USE_CURL=0" << std::endl;
 799
 800         fetch_result = HTTPFetchResult(fetch_request); // sets succeeded = false etc.
 801 }
 802
 803 #endif  // USE_CURL