src/util.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2015 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #if defined(HAVE_CONFIG_H)
   7 #include "config/bitcoin-config.h"
   8 #endif
   9
  10 #include "util.h"
  11
  12 #include "chainparamsbase.h"
  13 #include "random.h"
  14 #include "serialize.h"
  15 #include "sync.h"
  16 #include "utilstrencodings.h"
  17 #include "utiltime.h"
  18
  19 #include <stdarg.h>
  20
  21 #if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
  22 #include <pthread.h>
  23 #include <pthread_np.h>
  24 #endif
  25
  26 #ifndef WIN32
  27 // for posix_fallocate
  28 #ifdef __linux__
  29
  30 #ifdef _POSIX_C_SOURCE
  31 #undef _POSIX_C_SOURCE
  32 #endif
  33
  34 #define _POSIX_C_SOURCE 200112L
  35
  36 #endif // __linux__
  37
  38 #include <algorithm>
  39 #include <fcntl.h>
  40 #include <sys/resource.h>
  41 #include <sys/stat.h>
  42
  43 #else
  44
  45 #ifdef _MSC_VER
  46 #pragma warning(disable:4786)
  47 #pragma warning(disable:4804)
  48 #pragma warning(disable:4805)
  49 #pragma warning(disable:4717)
  50 #endif
  51
  52 #ifdef _WIN32_WINNT
  53 #undef _WIN32_WINNT
  54 #endif
  55 #define _WIN32_WINNT 0x0501
  56
  57 #ifdef _WIN32_IE
  58 #undef _WIN32_IE
  59 #endif
  60 #define _WIN32_IE 0x0501
  61
  62 #define WIN32_LEAN_AND_MEAN 1
  63 #ifndef NOMINMAX
  64 #define NOMINMAX
  65 #endif
  66
  67 #include <io.h> /* for _commit */
  68 #include <shlobj.h>
  69 #endif
  70
  71 #ifdef HAVE_SYS_PRCTL_H
  72 #include <sys/prctl.h>
  73 #endif
  74
  75 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
  76 #include <boost/algorithm/string/join.hpp>
  77 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
  78 #include <boost/filesystem.hpp>
  79 #include <boost/filesystem/fstream.hpp>
  80 #include <boost/foreach.hpp>
  81 #include <boost/program_options/detail/config_file.hpp>
  82 #include <boost/program_options/parsers.hpp>
  83 #include <boost/thread.hpp>
  84 #include <openssl/crypto.h>
  85 #include <openssl/rand.h>
  86 #include <openssl/conf.h>
  87
  88 // Work around clang compilation problem in Boost 1.46:
  89 // /usr/include/boost/program_options/detail/config_file.hpp:163:17: error: call to function 'to_internal' that is neither visible in the template definition nor found by argument-dependent lookup
  90 // See also: http://stackoverflow.com/questions/10020179/compilation-fail-in-boost-librairies-program-options
  91 //           http://clang.debian.net/status.php?version=3.0&key=CANNOT_FIND_FUNCTION
  92 namespace boost {
  93
  94     namespace program_options {
  95         std::string to_internal(const std::string&);
  96     }
  97
  98 } // namespace boost
  99
 100 using namespace std;
 101
 102 const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf";
 103 const char * const BITCOIN_PID_FILENAME = "bitcoind.pid";
 104
 105 map<string, string> mapArgs;
 106 map<string, vector<string> > mapMultiArgs;
 107 bool fDebug = false;
 108 bool fPrintToConsole = false;
 109 bool fPrintToDebugLog = true;
 110 bool fDaemon = false;
 111 bool fServer = false;
 112 string strMiscWarning;
 113 bool fLogTimestamps = DEFAULT_LOGTIMESTAMPS;
 114 bool fLogTimeMicros = DEFAULT_LOGTIMEMICROS;
 115 bool fLogIPs = DEFAULT_LOGIPS;
 116 std::atomic<bool> fReopenDebugLog(false);
 117 CTranslationInterface translationInterface;
 118
 119 /** Init OpenSSL library multithreading support */
 120 static CCriticalSection** ppmutexOpenSSL;
 121 void locking_callback(int mode, int i, const char* file, int line) NO_THREAD_SAFETY_ANALYSIS
 122 {
 123     if (mode & CRYPTO_LOCK) {
 124         ENTER_CRITICAL_SECTION(*ppmutexOpenSSL[i]);
 125     } else {
 126         LEAVE_CRITICAL_SECTION(*ppmutexOpenSSL[i]);
 127     }
 128 }
 129
 130 // Init
 131 class CInit
 132 {
 133 public:
 134     CInit()
 135     {
 136         // Init OpenSSL library multithreading support
 137         ppmutexOpenSSL = (CCriticalSection**)OPENSSL_malloc(CRYPTO_num_locks() * sizeof(CCriticalSection*));
 138         for (int i = 0; i < CRYPTO_num_locks(); i++)
 139             ppmutexOpenSSL[i] = new CCriticalSection();
 140         CRYPTO_set_locking_callback(locking_callback);
 141
 142         // OpenSSL can optionally load a config file which lists optional loadable modules and engines.
 143         // We don't use them so we don't require the config. However some of our libs may call functions
 144         // which attempt to load the config file, possibly resulting in an exit() or crash if it is missing
 145         // or corrupt. Explicitly tell OpenSSL not to try to load the file. The result for our libs will be
 146         // that the config appears to have been loaded and there are no modules/engines available.
 147         OPENSSL_no_config();
 148
 149 #ifdef WIN32
 150         // Seed OpenSSL PRNG with current contents of the screen
 151         RAND_screen();
 152 #endif
 153
 154         // Seed OpenSSL PRNG with performance counter
 155         RandAddSeed();
 156     }
 157     ~CInit()
 158     {
 159         // Securely erase the memory used by the PRNG
 160         RAND_cleanup();
 161         // Shutdown OpenSSL library multithreading support
 162         CRYPTO_set_locking_callback(NULL);
 163         for (int i = 0; i < CRYPTO_num_locks(); i++)
 164             delete ppmutexOpenSSL[i];
 165         OPENSSL_free(ppmutexOpenSSL);
 166     }
 167 }
 168 instance_of_cinit;
 169
 170 /**
 171  * LogPrintf() has been broken a couple of times now
 172  * by well-meaning people adding mutexes in the most straightforward way.
 173  * It breaks because it may be called by global destructors during shutdown.
 174  * Since the order of destruction of static/global objects is undefined,
 175  * defining a mutex as a global object doesn't work (the mutex gets
 176  * destroyed, and then some later destructor calls OutputDebugStringF,
 177  * maybe indirectly, and you get a core dump at shutdown trying to lock
 178  * the mutex).
 179  */
 180
 181 static boost::once_flag debugPrintInitFlag = BOOST_ONCE_INIT;
 182
 183 /**
 184  * We use boost::call_once() to make sure mutexDebugLog and
 185  * vMsgsBeforeOpenLog are initialized in a thread-safe manner.
 186  *
 187  * NOTE: fileout, mutexDebugLog and sometimes vMsgsBeforeOpenLog
 188  * are leaked on exit. This is ugly, but will be cleaned up by
 189  * the OS/libc. When the shutdown sequence is fully audited and
 190  * tested, explicit destruction of these objects can be implemented.
 191  */
 192 static FILE* fileout = NULL;
 193 static boost::mutex* mutexDebugLog = NULL;
 194 static list<string> *vMsgsBeforeOpenLog;
 195
 196 static int FileWriteStr(const std::string &str, FILE *fp)
 197 {
 198     return fwrite(str.data(), 1, str.size(), fp);
 199 }
 200
 201 static void DebugPrintInit()
 202 {
 203     assert(mutexDebugLog == NULL);
 204     mutexDebugLog = new boost::mutex();
 205     vMsgsBeforeOpenLog = new list<string>;
 206 }
 207
 208 void OpenDebugLog()
 209 {
 210     boost::call_once(&DebugPrintInit, debugPrintInitFlag);
 211     boost::mutex::scoped_lock scoped_lock(*mutexDebugLog);
 212
 213     assert(fileout == NULL);
 214     assert(vMsgsBeforeOpenLog);
 215     boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
 216     fileout = fopen(pathDebug.string().c_str(), "a");
 217     if (fileout) setbuf(fileout, NULL); // unbuffered
 218
 219     // dump buffered messages from before we opened the log
 220     while (!vMsgsBeforeOpenLog->empty()) {
 221         FileWriteStr(vMsgsBeforeOpenLog->front(), fileout);
 222         vMsgsBeforeOpenLog->pop_front();
 223     }
 224
 225     delete vMsgsBeforeOpenLog;
 226     vMsgsBeforeOpenLog = NULL;
 227 }
 228
 229 bool LogAcceptCategory(const char* category)
 230 {
 231     if (category != NULL)
 232     {
 233         if (!fDebug)
 234             return false;
 235
 236         // Give each thread quick access to -debug settings.
 237         // This helps prevent issues debugging global destructors,
 238         // where mapMultiArgs might be deleted before another
 239         // global destructor calls LogPrint()
 240         static boost::thread_specific_ptr<set<string> > ptrCategory;
 241         if (ptrCategory.get() == NULL)
 242         {
 243             const vector<string>& categories = mapMultiArgs["-debug"];
 244             ptrCategory.reset(new set<string>(categories.begin(), categories.end()));
 245             // thread_specific_ptr automatically deletes the set when the thread ends.
 246         }
 247         const set<string>& setCategories = *ptrCategory.get();
 248
 249         // if not debugging everything and not debugging specific category, LogPrint does nothing.
 250         if (setCategories.count(string("")) == 0 &&
 251             setCategories.count(string("1")) == 0 &&
 252             setCategories.count(string(category)) == 0)
 253             return false;
 254     }
 255     return true;
 256 }
 257
 258 /**
 259  * fStartedNewLine is a state variable held by the calling context that will
 260  * suppress printing of the timestamp when multiple calls are made that don't
 261  * end in a newline. Initialize it to true, and hold it, in the calling context.
 262  */
 263 static std::string LogTimestampStr(const std::string &str, bool *fStartedNewLine)
 264 {
 265     string strStamped;
 266
 267     if (!fLogTimestamps)
 268         return str;
 269
 270     if (*fStartedNewLine) {
 271         int64_t nTimeMicros = GetLogTimeMicros();
 272         strStamped = DateTimeStrFormat("%Y-%m-%d %H:%M:%S", nTimeMicros/1000000);
 273         if (fLogTimeMicros)
 274             strStamped += strprintf(".%06d", nTimeMicros%1000000);
 275         strStamped += ' ' + str;
 276     } else
 277         strStamped = str;
 278
 279     if (!str.empty() && str[str.size()-1] == '\n')
 280         *fStartedNewLine = true;
 281     else
 282         *fStartedNewLine = false;
 283
 284     return strStamped;
 285 }
 286
 287 int LogPrintStr(const std::string &str)
 288 {
 289     int ret = 0; // Returns total number of characters written
 290     static bool fStartedNewLine = true;
 291
 292     string strTimestamped = LogTimestampStr(str, &fStartedNewLine);
 293
 294     if (fPrintToConsole)
 295     {
 296         // print to console
 297         ret = fwrite(strTimestamped.data(), 1, strTimestamped.size(), stdout);
 298         fflush(stdout);
 299     }
 300     else if (fPrintToDebugLog)
 301     {
 302         boost::call_once(&DebugPrintInit, debugPrintInitFlag);
 303         boost::mutex::scoped_lock scoped_lock(*mutexDebugLog);
 304
 305         // buffer if we haven't opened the log yet
 306         if (fileout == NULL) {
 307             assert(vMsgsBeforeOpenLog);
 308             ret = strTimestamped.length();
 309             vMsgsBeforeOpenLog->push_back(strTimestamped);
 310         }
 311         else
 312         {
 313             // reopen the log file, if requested
 314             if (fReopenDebugLog) {
 315                 fReopenDebugLog = false;
 316                 boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
 317                 if (freopen(pathDebug.string().c_str(),"a",fileout) != NULL)
 318                     setbuf(fileout, NULL); // unbuffered
 319             }
 320
 321             ret = FileWriteStr(strTimestamped, fileout);
 322         }
 323     }
 324     return ret;
 325 }
 326
 327 /** Interpret string as boolean, for argument parsing */
 328 static bool InterpretBool(const std::string& strValue)
 329 {
 330     if (strValue.empty())
 331         return true;
 332     return (atoi(strValue) != 0);
 333 }
 334
 335 /** Turn -noX into -X=0 */
 336 static void InterpretNegativeSetting(std::string& strKey, std::string& strValue)
 337 {
 338     if (strKey.length()>3 && strKey[0]=='-' && strKey[1]=='n' && strKey[2]=='o')
 339     {
 340         strKey = "-" + strKey.substr(3);
 341         strValue = InterpretBool(strValue) ? "0" : "1";
 342     }
 343 }
 344
 345 void ParseParameters(int argc, const char* const argv[])
 346 {
 347     mapArgs.clear();
 348     mapMultiArgs.clear();
 349
 350     for (int i = 1; i < argc; i++)
 351     {
 352         std::string str(argv[i]);
 353         std::string strValue;
 354         size_t is_index = str.find('=');
 355         if (is_index != std::string::npos)
 356         {
 357             strValue = str.substr(is_index+1);
 358             str = str.substr(0, is_index);
 359         }
 360 #ifdef WIN32
 361         boost::to_lower(str);
 362         if (boost::algorithm::starts_with(str, "/"))
 363             str = "-" + str.substr(1);
 364 #endif
 365
 366         if (str[0] != '-')
 367             break;
 368
 369         // Interpret --foo as -foo.
 370         // If both --foo and -foo are set, the last takes effect.
 371         if (str.length() > 1 && str[1] == '-')
 372             str = str.substr(1);
 373         InterpretNegativeSetting(str, strValue);
 374
 375         mapArgs[str] = strValue;
 376         mapMultiArgs[str].push_back(strValue);
 377     }
 378 }
 379
 380 std::string GetArg(const std::string& strArg, const std::string& strDefault)
 381 {
 382     if (mapArgs.count(strArg))
 383         return mapArgs[strArg];
 384     return strDefault;
 385 }
 386
 387 int64_t GetArg(const std::string& strArg, int64_t nDefault)
 388 {
 389     if (mapArgs.count(strArg))
 390         return atoi64(mapArgs[strArg]);
 391     return nDefault;
 392 }
 393
 394 bool GetBoolArg(const std::string& strArg, bool fDefault)
 395 {
 396     if (mapArgs.count(strArg))
 397         return InterpretBool(mapArgs[strArg]);
 398     return fDefault;
 399 }
 400
 401 bool SoftSetArg(const std::string& strArg, const std::string& strValue)
 402 {
 403     if (mapArgs.count(strArg))
 404         return false;
 405     mapArgs[strArg] = strValue;
 406     return true;
 407 }
 408
 409 bool SoftSetBoolArg(const std::string& strArg, bool fValue)
 410 {
 411     if (fValue)
 412         return SoftSetArg(strArg, std::string("1"));
 413     else
 414         return SoftSetArg(strArg, std::string("0"));
 415 }
 416
 417 static const int screenWidth = 79;
 418 static const int optIndent = 2;
 419 static const int msgIndent = 7;
 420
 421 std::string HelpMessageGroup(const std::string &message) {
 422     return std::string(message) + std::string("\n\n");
 423 }
 424
 425 std::string HelpMessageOpt(const std::string &option, const std::string &message) {
 426     return std::string(optIndent,' ') + std::string(option) +
 427            std::string("\n") + std::string(msgIndent,' ') +
 428            FormatParagraph(message, screenWidth - msgIndent, msgIndent) +
 429            std::string("\n\n");
 430 }
 431
 432 static std::string FormatException(const std::exception* pex, const char* pszThread)
 433 {
 434 #ifdef WIN32
 435     char pszModule[MAX_PATH] = "";
 436     GetModuleFileNameA(NULL, pszModule, sizeof(pszModule));
 437 #else
 438     const char* pszModule = "bitcoin";
 439 #endif
 440     if (pex)
 441         return strprintf(
 442             "EXCEPTION: %s       \n%s       \n%s in %s       \n", typeid(*pex).name(), pex->what(), pszModule, pszThread);
 443     else
 444         return strprintf(
 445             "UNKNOWN EXCEPTION       \n%s in %s       \n", pszModule, pszThread);
 446 }
 447
 448 void PrintExceptionContinue(const std::exception* pex, const char* pszThread)
 449 {
 450     std::string message = FormatException(pex, pszThread);
 451     LogPrintf("\n\n************************\n%s\n", message);
 452     fprintf(stderr, "\n\n************************\n%s\n", message.c_str());
 453 }
 454
 455 boost::filesystem::path GetDefaultDataDir()
 456 {
 457     namespace fs = boost::filesystem;
 458     // Windows < Vista: C:\Documents and Settings\Username\Application Data\Bitcoin
 459     // Windows >= Vista: C:\Users\Username\AppData\Roaming\Bitcoin
 460     // Mac: ~/Library/Application Support/Bitcoin
 461     // Unix: ~/.bitcoin
 462 #ifdef WIN32
 463     // Windows
 464     return GetSpecialFolderPath(CSIDL_APPDATA) / "Bitcoin";
 465 #else
 466     fs::path pathRet;
 467     char* pszHome = getenv("HOME");
 468     if (pszHome == NULL || strlen(pszHome) == 0)
 469         pathRet = fs::path("/");
 470     else
 471         pathRet = fs::path(pszHome);
 472 #ifdef MAC_OSX
 473     // Mac
 474     return pathRet / "Library/Application Support/Bitcoin";
 475 #else
 476     // Unix
 477     return pathRet / ".bitcoin";
 478 #endif
 479 #endif
 480 }
 481
 482 static boost::filesystem::path pathCached;
 483 static boost::filesystem::path pathCachedNetSpecific;
 484 static CCriticalSection csPathCached;
 485
 486 const boost::filesystem::path &GetDataDir(bool fNetSpecific)
 487 {
 488     namespace fs = boost::filesystem;
 489
 490     LOCK(csPathCached);
 491
 492     fs::path &path = fNetSpecific ? pathCachedNetSpecific : pathCached;
 493
 494     // This can be called during exceptions by LogPrintf(), so we cache the
 495     // value so we don't have to do memory allocations after that.
 496     if (!path.empty())
 497         return path;
 498
 499     if (mapArgs.count("-datadir")) {
 500         path = fs::system_complete(mapArgs["-datadir"]);
 501         if (!fs::is_directory(path)) {
 502             path = "";
 503             return path;
 504         }
 505     } else {
 506         path = GetDefaultDataDir();
 507     }
 508     if (fNetSpecific)
 509         path /= BaseParams().DataDir();
 510
 511     fs::create_directories(path);
 512
 513     return path;
 514 }
 515
 516 void ClearDatadirCache()
 517 {
 518     pathCached = boost::filesystem::path();
 519     pathCachedNetSpecific = boost::filesystem::path();
 520 }
 521
 522 boost::filesystem::path GetConfigFile()
 523 {
 524     boost::filesystem::path pathConfigFile(GetArg("-conf", BITCOIN_CONF_FILENAME));
 525     if (!pathConfigFile.is_complete())
 526         pathConfigFile = GetDataDir(false) / pathConfigFile;
 527
 528     return pathConfigFile;
 529 }
 530
 531 void ReadConfigFile(map<string, string>& mapSettingsRet,
 532                     map<string, vector<string> >& mapMultiSettingsRet)
 533 {
 534     boost::filesystem::ifstream streamConfig(GetConfigFile());
 535     if (!streamConfig.good())
 536         return; // No bitcoin.conf file is OK
 537
 538     set<string> setOptions;
 539     setOptions.insert("*");
 540
 541     for (boost::program_options::detail::config_file_iterator it(streamConfig, setOptions), end; it != end; ++it)
 542     {
 543         // Don't overwrite existing settings so command line settings override bitcoin.conf
 544         string strKey = string("-") + it->string_key;
 545         string strValue = it->value[0];
 546         InterpretNegativeSetting(strKey, strValue);
 547         if (mapSettingsRet.count(strKey) == 0)
 548             mapSettingsRet[strKey] = strValue;
 549         mapMultiSettingsRet[strKey].push_back(strValue);
 550     }
 551     // If datadir is changed in .conf file:
 552     ClearDatadirCache();
 553 }
 554
 555 #ifndef WIN32
 556 boost::filesystem::path GetPidFile()
 557 {
 558     boost::filesystem::path pathPidFile(GetArg("-pid", BITCOIN_PID_FILENAME));
 559     if (!pathPidFile.is_complete()) pathPidFile = GetDataDir() / pathPidFile;
 560     return pathPidFile;
 561 }
 562
 563 void CreatePidFile(const boost::filesystem::path &path, pid_t pid)
 564 {
 565     FILE* file = fopen(path.string().c_str(), "w");
 566     if (file)
 567     {
 568         fprintf(file, "%d\n", pid);
 569         fclose(file);
 570     }
 571 }
 572 #endif
 573
 574 bool RenameOver(boost::filesystem::path src, boost::filesystem::path dest)
 575 {
 576 #ifdef WIN32
 577     return MoveFileExA(src.string().c_str(), dest.string().c_str(),
 578                        MOVEFILE_REPLACE_EXISTING) != 0;
 579 #else
 580     int rc = std::rename(src.string().c_str(), dest.string().c_str());
 581     return (rc == 0);
 582 #endif /* WIN32 */
 583 }
 584
 585 /**
 586  * Ignores exceptions thrown by Boost's create_directory if the requested directory exists.
 587  * Specifically handles case where path p exists, but it wasn't possible for the user to
 588  * write to the parent directory.
 589  */
 590 bool TryCreateDirectory(const boost::filesystem::path& p)
 591 {
 592     try
 593     {
 594         return boost::filesystem::create_directory(p);
 595     } catch (const boost::filesystem::filesystem_error&) {
 596         if (!boost::filesystem::exists(p) || !boost::filesystem::is_directory(p))
 597             throw;
 598     }
 599
 600     // create_directory didn't create the directory, it had to have existed already
 601     return false;
 602 }
 603
 604 void FileCommit(FILE *fileout)
 605 {
 606     fflush(fileout); // harmless if redundantly called
 607 #ifdef WIN32
 608     HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(fileout));
 609     FlushFileBuffers(hFile);
 610 #else
 611     #if defined(__linux__) || defined(__NetBSD__)
 612     fdatasync(fileno(fileout));
 613     #elif defined(__APPLE__) && defined(F_FULLFSYNC)
 614     fcntl(fileno(fileout), F_FULLFSYNC, 0);
 615     #else
 616     fsync(fileno(fileout));
 617     #endif
 618 #endif
 619 }
 620
 621 bool TruncateFile(FILE *file, unsigned int length) {
 622 #if defined(WIN32)
 623     return _chsize(_fileno(file), length) == 0;
 624 #else
 625     return ftruncate(fileno(file), length) == 0;
 626 #endif
 627 }
 628
 629 /**
 630  * this function tries to raise the file descriptor limit to the requested number.
 631  * It returns the actual file descriptor limit (which may be more or less than nMinFD)
 632  */
 633 int RaiseFileDescriptorLimit(int nMinFD) {
 634 #if defined(WIN32)
 635     return 2048;
 636 #else
 637     struct rlimit limitFD;
 638     if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
 639         if (limitFD.rlim_cur < (rlim_t)nMinFD) {
 640             limitFD.rlim_cur = nMinFD;
 641             if (limitFD.rlim_cur > limitFD.rlim_max)
 642                 limitFD.rlim_cur = limitFD.rlim_max;
 643             setrlimit(RLIMIT_NOFILE, &limitFD);
 644             getrlimit(RLIMIT_NOFILE, &limitFD);
 645         }
 646         return limitFD.rlim_cur;
 647     }
 648     return nMinFD; // getrlimit failed, assume it's fine
 649 #endif
 650 }
 651
 652 /**
 653  * this function tries to make a particular range of a file allocated (corresponding to disk space)
 654  * it is advisory, and the range specified in the arguments will never contain live data
 655  */
 656 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {
 657 #if defined(WIN32)
 658     // Windows-specific version
 659     HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
 660     LARGE_INTEGER nFileSize;
 661     int64_t nEndPos = (int64_t)offset + length;
 662     nFileSize.u.LowPart = nEndPos & 0xFFFFFFFF;
 663     nFileSize.u.HighPart = nEndPos >> 32;
 664     SetFilePointerEx(hFile, nFileSize, 0, FILE_BEGIN);
 665     SetEndOfFile(hFile);
 666 #elif defined(MAC_OSX)
 667     // OSX specific version
 668     fstore_t fst;
 669     fst.fst_flags = F_ALLOCATECONTIG;
 670     fst.fst_posmode = F_PEOFPOSMODE;
 671     fst.fst_offset = 0;
 672     fst.fst_length = (off_t)offset + length;
 673     fst.fst_bytesalloc = 0;
 674     if (fcntl(fileno(file), F_PREALLOCATE, &fst) == -1) {
 675         fst.fst_flags = F_ALLOCATEALL;
 676         fcntl(fileno(file), F_PREALLOCATE, &fst);
 677     }
 678     ftruncate(fileno(file), fst.fst_length);
 679 #elif defined(__linux__)
 680     // Version using posix_fallocate
 681     off_t nEndPos = (off_t)offset + length;
 682     posix_fallocate(fileno(file), 0, nEndPos);
 683 #else
 684     // Fallback version
 685     // TODO: just write one byte per block
 686     static const char buf[65536] = {};
 687     fseek(file, offset, SEEK_SET);
 688     while (length > 0) {
 689         unsigned int now = 65536;
 690         if (length < now)
 691             now = length;
 692         fwrite(buf, 1, now, file); // allowed to fail; this function is advisory anyway
 693         length -= now;
 694     }
 695 #endif
 696 }
 697
 698 void ShrinkDebugFile()
 699 {
 700     // Scroll debug.log if it's getting too big
 701     boost::filesystem::path pathLog = GetDataDir() / "debug.log";
 702     FILE* file = fopen(pathLog.string().c_str(), "r");
 703     if (file && boost::filesystem::file_size(pathLog) > 10 * 1000000)
 704     {
 705         // Restart the file with some of the end
 706         std::vector <char> vch(200000,0);
 707         fseek(file, -((long)vch.size()), SEEK_END);
 708         int nBytes = fread(begin_ptr(vch), 1, vch.size(), file);
 709         fclose(file);
 710
 711         file = fopen(pathLog.string().c_str(), "w");
 712         if (file)
 713         {
 714             fwrite(begin_ptr(vch), 1, nBytes, file);
 715             fclose(file);
 716         }
 717     }
 718     else if (file != NULL)
 719         fclose(file);
 720 }
 721
 722 #ifdef WIN32
 723 boost::filesystem::path GetSpecialFolderPath(int nFolder, bool fCreate)
 724 {
 725     namespace fs = boost::filesystem;
 726
 727     char pszPath[MAX_PATH] = "";
 728
 729     if(SHGetSpecialFolderPathA(NULL, pszPath, nFolder, fCreate))
 730     {
 731         return fs::path(pszPath);
 732     }
 733
 734     LogPrintf("SHGetSpecialFolderPathA() failed, could not obtain requested path.\n");
 735     return fs::path("");
 736 }
 737 #endif
 738
 739 void runCommand(const std::string& strCommand)
 740 {
 741     int nErr = ::system(strCommand.c_str());
 742     if (nErr)
 743         LogPrintf("runCommand error: system(%s) returned %d\n", strCommand, nErr);
 744 }
 745
 746 void RenameThread(const char* name)
 747 {
 748 #if defined(PR_SET_NAME)
 749     // Only the first 15 characters are used (16 - NUL terminator)
 750     ::prctl(PR_SET_NAME, name, 0, 0, 0);
 751 #elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
 752     pthread_set_name_np(pthread_self(), name);
 753
 754 #elif defined(MAC_OSX)
 755     pthread_setname_np(name);
 756 #else
 757     // Prevent warnings for unused parameters...
 758     (void)name;
 759 #endif
 760 }
 761
 762 void SetupEnvironment()
 763 {
 764     // On most POSIX systems (e.g. Linux, but not BSD) the environment's locale
 765     // may be invalid, in which case the "C" locale is used as fallback.
 766 #if !defined(WIN32) && !defined(MAC_OSX) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
 767     try {
 768         std::locale(""); // Raises a runtime error if current locale is invalid
 769     } catch (const std::runtime_error&) {
 770         setenv("LC_ALL", "C", 1);
 771     }
 772 #endif
 773     // The path locale is lazy initialized and to avoid deinitialization errors
 774     // in multithreading environments, it is set explicitly by the main thread.
 775     // A dummy locale is used to extract the internal default locale, used by
 776     // boost::filesystem::path, which is then used to explicitly imbue the path.
 777     std::locale loc = boost::filesystem::path::imbue(std::locale::classic());
 778     boost::filesystem::path::imbue(loc);
 779 }
 780
 781 bool SetupNetworking()
 782 {
 783 #ifdef WIN32
 784     // Initialize Windows Sockets
 785     WSADATA wsadata;
 786     int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
 787     if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
 788         return false;
 789 #endif
 790     return true;
 791 }
 792
 793 int GetNumCores()
 794 {
 795 #if BOOST_VERSION >= 105600
 796     return boost::thread::physical_concurrency();
 797 #else // Must fall back to hardware_concurrency, which unfortunately counts virtual cores
 798     return boost::thread::hardware_concurrency();
 799 #endif
 800 }
 801
 802 std::string CopyrightHolders(const std::string& strPrefix)
 803 {
 804     std::string strCopyrightHolders = strPrefix + _(COPYRIGHT_HOLDERS);
 805     if (strCopyrightHolders.find("%s") != strCopyrightHolders.npos) {
 806         strCopyrightHolders = strprintf(strCopyrightHolders, _(COPYRIGHT_HOLDERS_SUBSTITUTION));
 807     }
 808     if (strCopyrightHolders.find("Bitcoin Core developers") == strCopyrightHolders.npos) {
 809         strCopyrightHolders += "\n" + strPrefix + "The Bitcoin Core developers";
 810     }
 811     return strCopyrightHolders;
 812 }