aboutsummaryrefslogtreecommitdiff
path: root/src/util.cpp
blob: 9a9209c62140b6ae73a8a4d6d780936bd45ed557 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#if defined(HAVE_CONFIG_H)
#include "config/bitcoin-config.h"
#endif

#include "util.h"

#include "chainparamsbase.h"
#include "random.h"
#include "serialize.h"
#include "sync.h"
#include "utilstrencodings.h"
#include "utiltime.h"

#include <stdarg.h>

#if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
#include <pthread.h>
#include <pthread_np.h>
#endif

#ifndef WIN32
// for posix_fallocate
#ifdef __linux__

#ifdef _POSIX_C_SOURCE
#undef _POSIX_C_SOURCE
#endif

#define _POSIX_C_SOURCE 200112L

#endif // __linux__

#include <algorithm>
#include <fcntl.h>
#include <sys/resource.h>
#include <sys/stat.h>

#else

#ifdef _MSC_VER
#pragma warning(disable:4786)
#pragma warning(disable:4804)
#pragma warning(disable:4805)
#pragma warning(disable:4717)
#endif

#ifdef _WIN32_WINNT
#undef _WIN32_WINNT
#endif
#define _WIN32_WINNT 0x0501

#ifdef _WIN32_IE
#undef _WIN32_IE
#endif
#define _WIN32_IE 0x0501

#define WIN32_LEAN_AND_MEAN 1
#ifndef NOMINMAX
#define NOMINMAX
#endif

#include <io.h> /* for _commit */
#include <shlobj.h>
#endif

#ifdef HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif

#include <boost/algorithm/string/case_conv.hpp> // for to_lower()
#include <boost/algorithm/string/join.hpp>
#include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/foreach.hpp>
#include <boost/program_options/detail/config_file.hpp>
#include <boost/program_options/parsers.hpp>
#include <boost/thread.hpp>
#include <openssl/crypto.h>
#include <openssl/rand.h>
#include <openssl/conf.h>

// Work around clang compilation problem in Boost 1.46:
// /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
// See also: http://stackoverflow.com/questions/10020179/compilation-fail-in-boost-librairies-program-options
//           http://clang.debian.net/status.php?version=3.0&key=CANNOT_FIND_FUNCTION
namespace boost {

    namespace program_options {
        std::string to_internal(const std::string&);
    }

} // namespace boost

using namespace std;

const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf";
const char * const BITCOIN_PID_FILENAME = "bitcoind.pid";

map<string, string> mapArgs;
map<string, vector<string> > mapMultiArgs;
bool fDebug = false;
bool fPrintToConsole = false;
bool fPrintToDebugLog = true;
bool fDaemon = false;
bool fServer = false;
string strMiscWarning;
bool fLogTimestamps = DEFAULT_LOGTIMESTAMPS;
bool fLogTimeMicros = DEFAULT_LOGTIMEMICROS;
bool fLogIPs = DEFAULT_LOGIPS;
std::atomic<bool> fReopenDebugLog(false);
CTranslationInterface translationInterface;

/** Init OpenSSL library multithreading support */
static CCriticalSection** ppmutexOpenSSL;
void locking_callback(int mode, int i, const char* file, int line) NO_THREAD_SAFETY_ANALYSIS
{
    if (mode & CRYPTO_LOCK) {
        ENTER_CRITICAL_SECTION(*ppmutexOpenSSL[i]);
    } else {
        LEAVE_CRITICAL_SECTION(*ppmutexOpenSSL[i]);
    }
}

// Init
class CInit
{
public:
    CInit()
    {
        // Init OpenSSL library multithreading support
        ppmutexOpenSSL = (CCriticalSection**)OPENSSL_malloc(CRYPTO_num_locks() * sizeof(CCriticalSection*));
        for (int i = 0; i < CRYPTO_num_locks(); i++)
            ppmutexOpenSSL[i] = new CCriticalSection();
        CRYPTO_set_locking_callback(locking_callback);

        // OpenSSL can optionally load a config file which lists optional loadable modules and engines.
        // We don't use them so we don't require the config. However some of our libs may call functions
        // which attempt to load the config file, possibly resulting in an exit() or crash if it is missing
        // or corrupt. Explicitly tell OpenSSL not to try to load the file. The result for our libs will be
        // that the config appears to have been loaded and there are no modules/engines available.
        OPENSSL_no_config();

#ifdef WIN32
        // Seed OpenSSL PRNG with current contents of the screen
        RAND_screen();
#endif

        // Seed OpenSSL PRNG with performance counter
        RandAddSeed();
    }
    ~CInit()
    {
        // Securely erase the memory used by the PRNG
        RAND_cleanup();
        // Shutdown OpenSSL library multithreading support
        CRYPTO_set_locking_callback(NULL);
        for (int i = 0; i < CRYPTO_num_locks(); i++)
            delete ppmutexOpenSSL[i];
        OPENSSL_free(ppmutexOpenSSL);
    }
}
instance_of_cinit;

/**
 * LogPrintf() has been broken a couple of times now
 * by well-meaning people adding mutexes in the most straightforward way.
 * It breaks because it may be called by global destructors during shutdown.
 * Since the order of destruction of static/global objects is undefined,
 * defining a mutex as a global object doesn't work (the mutex gets
 * destroyed, and then some later destructor calls OutputDebugStringF,
 * maybe indirectly, and you get a core dump at shutdown trying to lock
 * the mutex).
 */

static boost::once_flag debugPrintInitFlag = BOOST_ONCE_INIT;

/**
 * We use boost::call_once() to make sure mutexDebugLog and
 * vMsgsBeforeOpenLog are initialized in a thread-safe manner.
 *
 * NOTE: fileout, mutexDebugLog and sometimes vMsgsBeforeOpenLog
 * are leaked on exit. This is ugly, but will be cleaned up by
 * the OS/libc. When the shutdown sequence is fully audited and
 * tested, explicit destruction of these objects can be implemented.
 */
static FILE* fileout = NULL;
static boost::mutex* mutexDebugLog = NULL;
static list<string> *vMsgsBeforeOpenLog;

static int FileWriteStr(const std::string &str, FILE *fp)
{
    return fwrite(str.data(), 1, str.size(), fp);
}

static void DebugPrintInit()
{
    assert(mutexDebugLog == NULL);
    mutexDebugLog = new boost::mutex();
    vMsgsBeforeOpenLog = new list<string>;
}

void OpenDebugLog()
{
    boost::call_once(&DebugPrintInit, debugPrintInitFlag);
    boost::mutex::scoped_lock scoped_lock(*mutexDebugLog);

    assert(fileout == NULL);
    assert(vMsgsBeforeOpenLog);
    boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
    fileout = fopen(pathDebug.string().c_str(), "a");
    if (fileout) setbuf(fileout, NULL); // unbuffered

    // dump buffered messages from before we opened the log
    while (!vMsgsBeforeOpenLog->empty()) {
        FileWriteStr(vMsgsBeforeOpenLog->front(), fileout);
        vMsgsBeforeOpenLog->pop_front();
    }

    delete vMsgsBeforeOpenLog;
    vMsgsBeforeOpenLog = NULL;
}

bool LogAcceptCategory(const char* category)
{
    if (category != NULL)
    {
        if (!fDebug)
            return false;

        // Give each thread quick access to -debug settings.
        // This helps prevent issues debugging global destructors,
        // where mapMultiArgs might be deleted before another
        // global destructor calls LogPrint()
        static boost::thread_specific_ptr<set<string> > ptrCategory;
        if (ptrCategory.get() == NULL)
        {
            const vector<string>& categories = mapMultiArgs["-debug"];
            ptrCategory.reset(new set<string>(categories.begin(), categories.end()));
            // thread_specific_ptr automatically deletes the set when the thread ends.
        }
        const set<string>& setCategories = *ptrCategory.get();

        // if not debugging everything and not debugging specific category, LogPrint does nothing.
        if (setCategories.count(string("")) == 0 &&
            setCategories.count(string("1")) == 0 &&
            setCategories.count(string(category)) == 0)
            return false;
    }
    return true;
}

/**
 * fStartedNewLine is a state variable held by the calling context that will
 * suppress printing of the timestamp when multiple calls are made that don't
 * end in a newline. Initialize it to true, and hold it, in the calling context.
 */
static std::string LogTimestampStr(const std::string &str, bool *fStartedNewLine)
{
    string strStamped;

    if (!fLogTimestamps)
        return str;

    if (*fStartedNewLine) {
        int64_t nTimeMicros = GetLogTimeMicros();
        strStamped = DateTimeStrFormat("%Y-%m-%d %H:%M:%S", nTimeMicros/1000000);
        if (fLogTimeMicros)
            strStamped += strprintf(".%06d", nTimeMicros%1000000);
        strStamped += ' ' + str;
    } else
        strStamped = str;

    if (!str.empty() && str[str.size()-1] == '\n')
        *fStartedNewLine = true;
    else
        *fStartedNewLine = false;

    return strStamped;
}

int LogPrintStr(const std::string &str)
{
    int ret = 0; // Returns total number of characters written
    static bool fStartedNewLine = true;

    string strTimestamped = LogTimestampStr(str, &fStartedNewLine);

    if (fPrintToConsole)
    {
        // print to console
        ret = fwrite(strTimestamped.data(), 1, strTimestamped.size(), stdout);
        fflush(stdout);
    }
    else if (fPrintToDebugLog)
    {
        boost::call_once(&DebugPrintInit, debugPrintInitFlag);
        boost::mutex::scoped_lock scoped_lock(*mutexDebugLog);

        // buffer if we haven't opened the log yet
        if (fileout == NULL) {
            assert(vMsgsBeforeOpenLog);
            ret = strTimestamped.length();
            vMsgsBeforeOpenLog->push_back(strTimestamped);
        }
        else
        {
            // reopen the log file, if requested
            if (fReopenDebugLog) {
                fReopenDebugLog = false;
                boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
                if (freopen(pathDebug.string().c_str(),"a",fileout) != NULL)
                    setbuf(fileout, NULL); // unbuffered
            }

            ret = FileWriteStr(strTimestamped, fileout);
        }
    }
    return ret;
}

/** Interpret string as boolean, for argument parsing */
static bool InterpretBool(const std::string& strValue)
{
    if (strValue.empty())
        return true;
    return (atoi(strValue) != 0);
}

/** Turn -noX into -X=0 */
static void InterpretNegativeSetting(std::string& strKey, std::string& strValue)
{
    if (strKey.length()>3 && strKey[0]=='-' && strKey[1]=='n' && strKey[2]=='o')
    {
        strKey = "-" + strKey.substr(3);
        strValue = InterpretBool(strValue) ? "0" : "1";
    }
}

void ParseParameters(int argc, const char* const argv[])
{
    mapArgs.clear();
    mapMultiArgs.clear();

    for (int i = 1; i < argc; i++)
    {
        std::string str(argv[i]);
        std::string strValue;
        size_t is_index = str.find('=');
        if (is_index != std::string::npos)
        {
            strValue = str.substr(is_index+1);
            str = str.substr(0, is_index);
        }
#ifdef WIN32
        boost::to_lower(str);
        if (boost::algorithm::starts_with(str, "/"))
            str = "-" + str.substr(1);
#endif

        if (str[0] != '-')
            break;

        // Interpret --foo as -foo.
        // If both --foo and -foo are set, the last takes effect.
        if (str.length() > 1 && str[1] == '-')
            str = str.substr(1);
        InterpretNegativeSetting(str, strValue);

        mapArgs[str] = strValue;
        mapMultiArgs[str].push_back(strValue);
    }
}

std::string GetArg(const std::string& strArg, const std::string& strDefault)
{
    if (mapArgs.count(strArg))
        return mapArgs[strArg];
    return strDefault;
}

int64_t GetArg(const std::string& strArg, int64_t nDefault)
{
    if (mapArgs.count(strArg))
        return atoi64(mapArgs[strArg]);
    return nDefault;
}

bool GetBoolArg(const std::string& strArg, bool fDefault)
{
    if (mapArgs.count(strArg))
        return InterpretBool(mapArgs[strArg]);
    return fDefault;
}

bool SoftSetArg(const std::string& strArg, const std::string& strValue)
{
    if (mapArgs.count(strArg))
        return false;
    mapArgs[strArg] = strValue;
    return true;
}

bool SoftSetBoolArg(const std::string& strArg, bool fValue)
{
    if (fValue)
        return SoftSetArg(strArg, std::string("1"));
    else
        return SoftSetArg(strArg, std::string("0"));
}

static const int screenWidth = 79;
static const int optIndent = 2;
static const int msgIndent = 7;

std::string HelpMessageGroup(const std::string &message) {
    return std::string(message) + std::string("\n\n");
}

std::string HelpMessageOpt(const std::string &option, const std::string &message) {
    return std::string(optIndent,' ') + std::string(option) +
           std::string("\n") + std::string(msgIndent,' ') +
           FormatParagraph(message, screenWidth - msgIndent, msgIndent) +
           std::string("\n\n");
}

static std::string FormatException(const std::exception* pex, const char* pszThread)
{
#ifdef WIN32
    char pszModule[MAX_PATH] = "";
    GetModuleFileNameA(NULL, pszModule, sizeof(pszModule));
#else
    const char* pszModule = "bitcoin";
#endif
    if (pex)
        return strprintf(
            "EXCEPTION: %s       \n%s       \n%s in %s       \n", typeid(*pex).name(), pex->what(), pszModule, pszThread);
    else
        return strprintf(
            "UNKNOWN EXCEPTION       \n%s in %s       \n", pszModule, pszThread);
}

void PrintExceptionContinue(const std::exception* pex, const char* pszThread)
{
    std::string message = FormatException(pex, pszThread);
    LogPrintf("\n\n************************\n%s\n", message);
    fprintf(stderr, "\n\n************************\n%s\n", message.c_str());
}

boost::filesystem::path GetDefaultDataDir()
{
    namespace fs = boost::filesystem;
    // Windows < Vista: C:\Documents and Settings\Username\Application Data\Bitcoin
    // Windows >= Vista: C:\Users\Username\AppData\Roaming\Bitcoin
    // Mac: ~/Library/Application Support/Bitcoin
    // Unix: ~/.bitcoin
#ifdef WIN32
    // Windows
    return GetSpecialFolderPath(CSIDL_APPDATA) / "Bitcoin";
#else
    fs::path pathRet;
    char* pszHome = getenv("HOME");
    if (pszHome == NULL || strlen(pszHome) == 0)
        pathRet = fs::path("/");
    else
        pathRet = fs::path(pszHome);
#ifdef MAC_OSX
    // Mac
    return pathRet / "Library/Application Support/Bitcoin";
#else
    // Unix
    return pathRet / ".bitcoin";
#endif
#endif
}

static boost::filesystem::path pathCached;
static boost::filesystem::path pathCachedNetSpecific;
static CCriticalSection csPathCached;

const boost::filesystem::path &GetDataDir(bool fNetSpecific)
{
    namespace fs = boost::filesystem;

    LOCK(csPathCached);

    fs::path &path = fNetSpecific ? pathCachedNetSpecific : pathCached;

    // This can be called during exceptions by LogPrintf(), so we cache the
    // value so we don't have to do memory allocations after that.
    if (!path.empty())
        return path;

    if (mapArgs.count("-datadir")) {
        path = fs::system_complete(mapArgs["-datadir"]);
        if (!fs::is_directory(path)) {
            path = "";
            return path;
        }
    } else {
        path = GetDefaultDataDir();
    }
    if (fNetSpecific)
        path /= BaseParams().DataDir();

    fs::create_directories(path);

    return path;
}

void ClearDatadirCache()
{
    pathCached = boost::filesystem::path();
    pathCachedNetSpecific = boost::filesystem::path();
}

boost::filesystem::path GetConfigFile()
{
    boost::filesystem::path pathConfigFile(GetArg("-conf", BITCOIN_CONF_FILENAME));
    if (!pathConfigFile.is_complete())
        pathConfigFile = GetDataDir(false) / pathConfigFile;

    return pathConfigFile;
}

void ReadConfigFile(map<string, string>& mapSettingsRet,
                    map<string, vector<string> >& mapMultiSettingsRet)
{
    boost::filesystem::ifstream streamConfig(GetConfigFile());
    if (!streamConfig.good())
        return; // No bitcoin.conf file is OK

    set<string> setOptions;
    setOptions.insert("*");

    for (boost::program_options::detail::config_file_iterator it(streamConfig, setOptions), end; it != end; ++it)
    {
        // Don't overwrite existing settings so command line settings override bitcoin.conf
        string strKey = string("-") + it->string_key;
        string strValue = it->value[0];
        InterpretNegativeSetting(strKey, strValue);
        if (mapSettingsRet.count(strKey) == 0)
            mapSettingsRet[strKey] = strValue;
        mapMultiSettingsRet[strKey].push_back(strValue);
    }
    // If datadir is changed in .conf file:
    ClearDatadirCache();
}

#ifndef WIN32
boost::filesystem::path GetPidFile()
{
    boost::filesystem::path pathPidFile(GetArg("-pid", BITCOIN_PID_FILENAME));
    if (!pathPidFile.is_complete()) pathPidFile = GetDataDir() / pathPidFile;
    return pathPidFile;
}

void CreatePidFile(const boost::filesystem::path &path, pid_t pid)
{
    FILE* file = fopen(path.string().c_str(), "w");
    if (file)
    {
        fprintf(file, "%d\n", pid);
        fclose(file);
    }
}
#endif

bool RenameOver(boost::filesystem::path src, boost::filesystem::path dest)
{
#ifdef WIN32
    return MoveFileExA(src.string().c_str(), dest.string().c_str(),
                       MOVEFILE_REPLACE_EXISTING) != 0;
#else
    int rc = std::rename(src.string().c_str(), dest.string().c_str());
    return (rc == 0);
#endif /* WIN32 */
}

/**
 * Ignores exceptions thrown by Boost's create_directory if the requested directory exists.
 * Specifically handles case where path p exists, but it wasn't possible for the user to
 * write to the parent directory.
 */
bool TryCreateDirectory(const boost::filesystem::path& p)
{
    try
    {
        return boost::filesystem::create_directory(p);
    } catch (const boost::filesystem::filesystem_error&) {
        if (!boost::filesystem::exists(p) || !boost::filesystem::is_directory(p))
            throw;
    }

    // create_directory didn't create the directory, it had to have existed already
    return false;
}

void FileCommit(FILE *fileout)
{
    fflush(fileout); // harmless if redundantly called
#ifdef WIN32
    HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(fileout));
    FlushFileBuffers(hFile);
#else
    #if defined(__linux__) || defined(__NetBSD__)
    fdatasync(fileno(fileout));
    #elif defined(__APPLE__) && defined(F_FULLFSYNC)
    fcntl(fileno(fileout), F_FULLFSYNC, 0);
    #else
    fsync(fileno(fileout));
    #endif
#endif
}

bool TruncateFile(FILE *file, unsigned int length) {
#if defined(WIN32)
    return _chsize(_fileno(file), length) == 0;
#else
    return ftruncate(fileno(file), length) == 0;
#endif
}

/**
 * this function tries to raise the file descriptor limit to the requested number.
 * It returns the actual file descriptor limit (which may be more or less than nMinFD)
 */
int RaiseFileDescriptorLimit(int nMinFD) {
#if defined(WIN32)
    return 2048;
#else
    struct rlimit limitFD;
    if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
        if (limitFD.rlim_cur < (rlim_t)nMinFD) {
            limitFD.rlim_cur = nMinFD;
            if (limitFD.rlim_cur > limitFD.rlim_max)
                limitFD.rlim_cur = limitFD.rlim_max;
            setrlimit(RLIMIT_NOFILE, &limitFD);
            getrlimit(RLIMIT_NOFILE, &limitFD);
        }
        return limitFD.rlim_cur;
    }
    return nMinFD; // getrlimit failed, assume it's fine
#endif
}

/**
 * this function tries to make a particular range of a file allocated (corresponding to disk space)
 * it is advisory, and the range specified in the arguments will never contain live data
 */
void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {
#if defined(WIN32)
    // Windows-specific version
    HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
    LARGE_INTEGER nFileSize;
    int64_t nEndPos = (int64_t)offset + length;
    nFileSize.u.LowPart = nEndPos & 0xFFFFFFFF;
    nFileSize.u.HighPart = nEndPos >> 32;
    SetFilePointerEx(hFile, nFileSize, 0, FILE_BEGIN);
    SetEndOfFile(hFile);
#elif defined(MAC_OSX)
    // OSX specific version
    fstore_t fst;
    fst.fst_flags = F_ALLOCATECONTIG;
    fst.fst_posmode = F_PEOFPOSMODE;
    fst.fst_offset = 0;
    fst.fst_length = (off_t)offset + length;
    fst.fst_bytesalloc = 0;
    if (fcntl(fileno(file), F_PREALLOCATE, &fst) == -1) {
        fst.fst_flags = F_ALLOCATEALL;
        fcntl(fileno(file), F_PREALLOCATE, &fst);
    }
    ftruncate(fileno(file), fst.fst_length);
#elif defined(__linux__)
    // Version using posix_fallocate
    off_t nEndPos = (off_t)offset + length;
    posix_fallocate(fileno(file), 0, nEndPos);
#else
    // Fallback version
    // TODO: just write one byte per block
    static const char buf[65536] = {};
    fseek(file, offset, SEEK_SET);
    while (length > 0) {
        unsigned int now = 65536;
        if (length < now)
            now = length;
        fwrite(buf, 1, now, file); // allowed to fail; this function is advisory anyway
        length -= now;
    }
#endif
}

void ShrinkDebugFile()
{
    // Scroll debug.log if it's getting too big
    boost::filesystem::path pathLog = GetDataDir() / "debug.log";
    FILE* file = fopen(pathLog.string().c_str(), "r");
    if (file && boost::filesystem::file_size(pathLog) > 10 * 1000000)
    {
        // Restart the file with some of the end
        std::vector <char> vch(200000,0);
        fseek(file, -((long)vch.size()), SEEK_END);
        int nBytes = fread(begin_ptr(vch), 1, vch.size(), file);
        fclose(file);

        file = fopen(pathLog.string().c_str(), "w");
        if (file)
        {
            fwrite(begin_ptr(vch), 1, nBytes, file);
            fclose(file);
        }
    }
    else if (file != NULL)
        fclose(file);
}

#ifdef WIN32
boost::filesystem::path GetSpecialFolderPath(int nFolder, bool fCreate)
{
    namespace fs = boost::filesystem;

    char pszPath[MAX_PATH] = "";

    if(SHGetSpecialFolderPathA(NULL, pszPath, nFolder, fCreate))
    {
        return fs::path(pszPath);
    }

    LogPrintf("SHGetSpecialFolderPathA() failed, could not obtain requested path.\n");
    return fs::path("");
}
#endif

void runCommand(const std::string& strCommand)
{
    int nErr = ::system(strCommand.c_str());
    if (nErr)
        LogPrintf("runCommand error: system(%s) returned %d\n", strCommand, nErr);
}

void RenameThread(const char* name)
{
#if defined(PR_SET_NAME)
    // Only the first 15 characters are used (16 - NUL terminator)
    ::prctl(PR_SET_NAME, name, 0, 0, 0);
#elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
    pthread_set_name_np(pthread_self(), name);

#elif defined(MAC_OSX)
    pthread_setname_np(name);
#else
    // Prevent warnings for unused parameters...
    (void)name;
#endif
}

void SetupEnvironment()
{
    // On most POSIX systems (e.g. Linux, but not BSD) the environment's locale
    // may be invalid, in which case the "C" locale is used as fallback.
#if !defined(WIN32) && !defined(MAC_OSX) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
    try {
        std::locale(""); // Raises a runtime error if current locale is invalid
    } catch (const std::runtime_error&) {
        setenv("LC_ALL", "C", 1);
    }
#endif
    // The path locale is lazy initialized and to avoid deinitialization errors
    // in multithreading environments, it is set explicitly by the main thread.
    // A dummy locale is used to extract the internal default locale, used by
    // boost::filesystem::path, which is then used to explicitly imbue the path.
    std::locale loc = boost::filesystem::path::imbue(std::locale::classic());
    boost::filesystem::path::imbue(loc);
}

bool SetupNetworking()
{
#ifdef WIN32
    // Initialize Windows Sockets
    WSADATA wsadata;
    int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
    if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
        return false;
#endif
    return true;
}

int GetNumCores()
{
#if BOOST_VERSION >= 105600
    return boost::thread::physical_concurrency();
#else // Must fall back to hardware_concurrency, which unfortunately counts virtual cores
    return boost::thread::hardware_concurrency();
#endif
}

std::string CopyrightHolders(const std::string& strPrefix)
{
    std::string strCopyrightHolders = strPrefix + _(COPYRIGHT_HOLDERS);
    if (strCopyrightHolders.find("%s") != strCopyrightHolders.npos) {
        strCopyrightHolders = strprintf(strCopyrightHolders, _(COPYRIGHT_HOLDERS_SUBSTITUTION));
    }
    if (strCopyrightHolders.find("Bitcoin Core developers") == strCopyrightHolders.npos) {
        strCopyrightHolders += "\n" + strPrefix + "The Bitcoin Core developers";
    }
    return strCopyrightHolders;
}