dash/src/utilstrencodings.cpp
Wladimir J. van der Laan 9938dd83d4 Merge #10357: Allow setting nMinimumChainWork on command line
eac64bb7a [qa] Test nMinimumChainWork (Suhas Daftuar)
0311836f6 Allow setting nMinimumChainWork on command line (Suhas Daftuar)

Pull request description:

  As discussed briefly here: https://botbot.me/freenode/bitcoin-core-dev/2017-02-28/?msg=81712308&page=4

  This adds a hidden command line option for setting `nMinimumChainWork`, which allows us to test this parameter in our functional tests, as well as allowing for niche use cases like syncing nodes that are otherwise disconnected from the network.

  See also #10345, which proposes a new use of `nMinimumChainWork`.

Tree-SHA512: fe4d8f4f289697615c98d8760f1cc74c076110310ea0b5b875fcab78c127da9195b4eb84148aebacc7606c246e5773d3f13bd5d9559d0a8bffac20a3a28c62df
2019-09-29 12:42:14 +02:00

735 lines
23 KiB
C++

// 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.
#include "utilstrencodings.h"
#include "tinyformat.h"
#include <cstdlib>
#include <cstring>
#include <errno.h>
#include <limits>
static const std::string CHARS_ALPHA_NUM = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
static const std::string SAFE_CHARS[] =
{
CHARS_ALPHA_NUM + " .,;-_/:?@()", // SAFE_CHARS_DEFAULT
CHARS_ALPHA_NUM + " .,;-_?@", // SAFE_CHARS_UA_COMMENT
CHARS_ALPHA_NUM + ".-_", // SAFE_CHARS_FILENAME
};
std::string SanitizeString(const std::string& str, int rule)
{
std::string strResult;
for (std::string::size_type i = 0; i < str.size(); i++)
{
if (SAFE_CHARS[rule].find(str[i]) != std::string::npos)
strResult.push_back(str[i]);
}
return strResult;
}
const signed char p_util_hexdigit[256] =
{ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
0,1,2,3,4,5,6,7,8,9,-1,-1,-1,-1,-1,-1,
-1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, };
signed char HexDigit(char c)
{
return p_util_hexdigit[(unsigned char)c];
}
bool IsHex(const std::string& str)
{
for(std::string::const_iterator it(str.begin()); it != str.end(); ++it)
{
if (HexDigit(*it) < 0)
return false;
}
return (str.size() > 0) && (str.size()%2 == 0);
}
bool IsHexNumber(const std::string& str)
{
size_t starting_location = 0;
if (str.size() > 2 && *str.begin() == '0' && *(str.begin()+1) == 'x') {
starting_location = 2;
}
for (auto c : str.substr(starting_location)) {
if (HexDigit(c) < 0) return false;
}
// Return false for empty string or "0x".
return (str.size() > starting_location);
}
std::vector<unsigned char> ParseHex(const char* psz)
{
// convert hex dump to vector
std::vector<unsigned char> vch;
while (true)
{
while (isspace(*psz))
psz++;
signed char c = HexDigit(*psz++);
if (c == (signed char)-1)
break;
unsigned char n = (c << 4);
c = HexDigit(*psz++);
if (c == (signed char)-1)
break;
n |= c;
vch.push_back(n);
}
return vch;
}
std::vector<unsigned char> ParseHex(const std::string& str)
{
return ParseHex(str.c_str());
}
void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
size_t colon = in.find_last_of(':');
// if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
bool fHaveColon = colon != in.npos;
bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
int32_t n;
if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
in = in.substr(0, colon);
portOut = n;
}
}
if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
hostOut = in.substr(1, in.size()-2);
else
hostOut = in;
}
std::string EncodeBase64(const unsigned char* pch, size_t len)
{
static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
std::string strRet = "";
strRet.reserve((len+2)/3*4);
int mode=0, left=0;
const unsigned char *pchEnd = pch+len;
while (pch<pchEnd)
{
int enc = *(pch++);
switch (mode)
{
case 0: // we have no bits
strRet += pbase64[enc >> 2];
left = (enc & 3) << 4;
mode = 1;
break;
case 1: // we have two bits
strRet += pbase64[left | (enc >> 4)];
left = (enc & 15) << 2;
mode = 2;
break;
case 2: // we have four bits
strRet += pbase64[left | (enc >> 6)];
strRet += pbase64[enc & 63];
mode = 0;
break;
}
}
if (mode)
{
strRet += pbase64[left];
strRet += '=';
if (mode == 1)
strRet += '=';
}
return strRet;
}
std::string EncodeBase64(const std::string& str)
{
return EncodeBase64((const unsigned char*)str.c_str(), str.size());
}
std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
{
static const int decode64_table[256] =
{
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1,
-1, -1, -1, -1, -1, 0, 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, -1, -1, -1, -1, -1, -1, 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, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
if (pfInvalid)
*pfInvalid = false;
std::vector<unsigned char> vchRet;
vchRet.reserve(strlen(p)*3/4);
int mode = 0;
int left = 0;
while (1)
{
int dec = decode64_table[(unsigned char)*p];
if (dec == -1) break;
p++;
switch (mode)
{
case 0: // we have no bits and get 6
left = dec;
mode = 1;
break;
case 1: // we have 6 bits and keep 4
vchRet.push_back((left<<2) | (dec>>4));
left = dec & 15;
mode = 2;
break;
case 2: // we have 4 bits and get 6, we keep 2
vchRet.push_back((left<<4) | (dec>>2));
left = dec & 3;
mode = 3;
break;
case 3: // we have 2 bits and get 6
vchRet.push_back((left<<6) | dec);
mode = 0;
break;
}
}
if (pfInvalid)
switch (mode)
{
case 0: // 4n base64 characters processed: ok
break;
case 1: // 4n+1 base64 character processed: impossible
*pfInvalid = true;
break;
case 2: // 4n+2 base64 characters processed: require '=='
if (left || p[0] != '=' || p[1] != '=' || decode64_table[(unsigned char)p[2]] != -1)
*pfInvalid = true;
break;
case 3: // 4n+3 base64 characters processed: require '='
if (left || p[0] != '=' || decode64_table[(unsigned char)p[1]] != -1)
*pfInvalid = true;
break;
}
return vchRet;
}
std::string DecodeBase64(const std::string& str)
{
std::vector<unsigned char> vchRet = DecodeBase64(str.c_str());
return std::string((const char*)vchRet.data(), vchRet.size());
}
std::string EncodeBase32(const unsigned char* pch, size_t len)
{
static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
std::string strRet="";
strRet.reserve((len+4)/5*8);
int mode=0, left=0;
const unsigned char *pchEnd = pch+len;
while (pch<pchEnd)
{
int enc = *(pch++);
switch (mode)
{
case 0: // we have no bits
strRet += pbase32[enc >> 3];
left = (enc & 7) << 2;
mode = 1;
break;
case 1: // we have three bits
strRet += pbase32[left | (enc >> 6)];
strRet += pbase32[(enc >> 1) & 31];
left = (enc & 1) << 4;
mode = 2;
break;
case 2: // we have one bit
strRet += pbase32[left | (enc >> 4)];
left = (enc & 15) << 1;
mode = 3;
break;
case 3: // we have four bits
strRet += pbase32[left | (enc >> 7)];
strRet += pbase32[(enc >> 2) & 31];
left = (enc & 3) << 3;
mode = 4;
break;
case 4: // we have two bits
strRet += pbase32[left | (enc >> 5)];
strRet += pbase32[enc & 31];
mode = 0;
}
}
static const int nPadding[5] = {0, 6, 4, 3, 1};
if (mode)
{
strRet += pbase32[left];
for (int n=0; n<nPadding[mode]; n++)
strRet += '=';
}
return strRet;
}
std::string EncodeBase32(const std::string& str)
{
return EncodeBase32((const unsigned char*)str.c_str(), str.size());
}
std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
{
static const int decode32_table[256] =
{
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1,
-1, -1, -1, -1, -1, 0, 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, -1, -1, -1, -1, -1, -1, 0, 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, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
if (pfInvalid)
*pfInvalid = false;
std::vector<unsigned char> vchRet;
vchRet.reserve((strlen(p))*5/8);
int mode = 0;
int left = 0;
while (1)
{
int dec = decode32_table[(unsigned char)*p];
if (dec == -1) break;
p++;
switch (mode)
{
case 0: // we have no bits and get 5
left = dec;
mode = 1;
break;
case 1: // we have 5 bits and keep 2
vchRet.push_back((left<<3) | (dec>>2));
left = dec & 3;
mode = 2;
break;
case 2: // we have 2 bits and keep 7
left = left << 5 | dec;
mode = 3;
break;
case 3: // we have 7 bits and keep 4
vchRet.push_back((left<<1) | (dec>>4));
left = dec & 15;
mode = 4;
break;
case 4: // we have 4 bits, and keep 1
vchRet.push_back((left<<4) | (dec>>1));
left = dec & 1;
mode = 5;
break;
case 5: // we have 1 bit, and keep 6
left = left << 5 | dec;
mode = 6;
break;
case 6: // we have 6 bits, and keep 3
vchRet.push_back((left<<2) | (dec>>3));
left = dec & 7;
mode = 7;
break;
case 7: // we have 3 bits, and keep 0
vchRet.push_back((left<<5) | dec);
mode = 0;
break;
}
}
if (pfInvalid)
switch (mode)
{
case 0: // 8n base32 characters processed: ok
break;
case 1: // 8n+1 base32 characters processed: impossible
case 3: // +3
case 6: // +6
*pfInvalid = true;
break;
case 2: // 8n+2 base32 characters processed: require '======'
if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || p[4] != '=' || p[5] != '=' || decode32_table[(unsigned char)p[6]] != -1)
*pfInvalid = true;
break;
case 4: // 8n+4 base32 characters processed: require '===='
if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || decode32_table[(unsigned char)p[4]] != -1)
*pfInvalid = true;
break;
case 5: // 8n+5 base32 characters processed: require '==='
if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || decode32_table[(unsigned char)p[3]] != -1)
*pfInvalid = true;
break;
case 7: // 8n+7 base32 characters processed: require '='
if (left || p[0] != '=' || decode32_table[(unsigned char)p[1]] != -1)
*pfInvalid = true;
break;
}
return vchRet;
}
std::string DecodeBase32(const std::string& str)
{
std::vector<unsigned char> vchRet = DecodeBase32(str.c_str());
return std::string((const char*)vchRet.data(), vchRet.size());
}
static bool ParsePrechecks(const std::string& str)
{
if (str.empty()) // No empty string allowed
return false;
if (str.size() >= 1 && (isspace(str[0]) || isspace(str[str.size()-1]))) // No padding allowed
return false;
if (str.size() != strlen(str.c_str())) // No embedded NUL characters allowed
return false;
return true;
}
bool ParseInt32(const std::string& str, int32_t *out)
{
if (!ParsePrechecks(str))
return false;
char *endp = nullptr;
errno = 0; // strtol will not set errno if valid
long int n = strtol(str.c_str(), &endp, 10);
if(out) *out = (int32_t)n;
// Note that strtol returns a *long int*, so even if strtol doesn't report an over/underflow
// we still have to check that the returned value is within the range of an *int32_t*. On 64-bit
// platforms the size of these types may be different.
return endp && *endp == 0 && !errno &&
n >= std::numeric_limits<int32_t>::min() &&
n <= std::numeric_limits<int32_t>::max();
}
bool ParseInt64(const std::string& str, int64_t *out)
{
if (!ParsePrechecks(str))
return false;
char *endp = nullptr;
errno = 0; // strtoll will not set errno if valid
long long int n = strtoll(str.c_str(), &endp, 10);
if(out) *out = (int64_t)n;
// Note that strtoll returns a *long long int*, so even if strtol doesn't report an over/underflow
// we still have to check that the returned value is within the range of an *int64_t*.
return endp && *endp == 0 && !errno &&
n >= std::numeric_limits<int64_t>::min() &&
n <= std::numeric_limits<int64_t>::max();
}
bool ParseUInt32(const std::string& str, uint32_t *out)
{
if (!ParsePrechecks(str))
return false;
if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoul accepts these by default if they fit in the range
return false;
char *endp = nullptr;
errno = 0; // strtoul will not set errno if valid
unsigned long int n = strtoul(str.c_str(), &endp, 10);
if(out) *out = (uint32_t)n;
// Note that strtoul returns a *unsigned long int*, so even if it doesn't report an over/underflow
// we still have to check that the returned value is within the range of an *uint32_t*. On 64-bit
// platforms the size of these types may be different.
return endp && *endp == 0 && !errno &&
n <= std::numeric_limits<uint32_t>::max();
}
bool ParseUInt64(const std::string& str, uint64_t *out)
{
if (!ParsePrechecks(str))
return false;
if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoull accepts these by default if they fit in the range
return false;
char *endp = nullptr;
errno = 0; // strtoull will not set errno if valid
unsigned long long int n = strtoull(str.c_str(), &endp, 10);
if(out) *out = (uint64_t)n;
// Note that strtoull returns a *unsigned long long int*, so even if it doesn't report an over/underflow
// we still have to check that the returned value is within the range of an *uint64_t*.
return endp && *endp == 0 && !errno &&
n <= std::numeric_limits<uint64_t>::max();
}
bool ParseDouble(const std::string& str, double *out)
{
if (!ParsePrechecks(str))
return false;
if (str.size() >= 2 && str[0] == '0' && str[1] == 'x') // No hexadecimal floats allowed
return false;
std::istringstream text(str);
text.imbue(std::locale::classic());
double result;
text >> result;
if(out) *out = result;
return text.eof() && !text.fail();
}
std::string FormatParagraph(const std::string& in, size_t width, size_t indent)
{
std::stringstream out;
size_t ptr = 0;
size_t indented = 0;
while (ptr < in.size())
{
size_t lineend = in.find_first_of('\n', ptr);
if (lineend == std::string::npos) {
lineend = in.size();
}
const size_t linelen = lineend - ptr;
const size_t rem_width = width - indented;
if (linelen <= rem_width) {
out << in.substr(ptr, linelen + 1);
ptr = lineend + 1;
indented = 0;
} else {
size_t finalspace = in.find_last_of(" \n", ptr + rem_width);
if (finalspace == std::string::npos || finalspace < ptr) {
// No place to break; just include the entire word and move on
finalspace = in.find_first_of("\n ", ptr);
if (finalspace == std::string::npos) {
// End of the string, just add it and break
out << in.substr(ptr);
break;
}
}
out << in.substr(ptr, finalspace - ptr) << "\n";
if (in[finalspace] == '\n') {
indented = 0;
} else if (indent) {
out << std::string(indent, ' ');
indented = indent;
}
ptr = finalspace + 1;
}
}
return out.str();
}
std::string i64tostr(int64_t n)
{
return strprintf("%d", n);
}
std::string itostr(int n)
{
return strprintf("%d", n);
}
int64_t atoi64(const char* psz)
{
#ifdef _MSC_VER
return _atoi64(psz);
#else
return strtoll(psz, nullptr, 10);
#endif
}
int64_t atoi64(const std::string& str)
{
#ifdef _MSC_VER
return _atoi64(str.c_str());
#else
return strtoll(str.c_str(), nullptr, 10);
#endif
}
int atoi(const std::string& str)
{
return atoi(str.c_str());
}
/** Upper bound for mantissa.
* 10^18-1 is the largest arbitrary decimal that will fit in a signed 64-bit integer.
* Larger integers cannot consist of arbitrary combinations of 0-9:
*
* 999999999999999999 1^18-1
* 9223372036854775807 (1<<63)-1 (max int64_t)
* 9999999999999999999 1^19-1 (would overflow)
*/
static const int64_t UPPER_BOUND = 1000000000000000000LL - 1LL;
/** Helper function for ParseFixedPoint */
static inline bool ProcessMantissaDigit(char ch, int64_t &mantissa, int &mantissa_tzeros)
{
if(ch == '0')
++mantissa_tzeros;
else {
for (int i=0; i<=mantissa_tzeros; ++i) {
if (mantissa > (UPPER_BOUND / 10LL))
return false; /* overflow */
mantissa *= 10;
}
mantissa += ch - '0';
mantissa_tzeros = 0;
}
return true;
}
bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out)
{
int64_t mantissa = 0;
int64_t exponent = 0;
int mantissa_tzeros = 0;
bool mantissa_sign = false;
bool exponent_sign = false;
int ptr = 0;
int end = val.size();
int point_ofs = 0;
if (ptr < end && val[ptr] == '-') {
mantissa_sign = true;
++ptr;
}
if (ptr < end)
{
if (val[ptr] == '0') {
/* pass single 0 */
++ptr;
} else if (val[ptr] >= '1' && val[ptr] <= '9') {
while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
return false; /* overflow */
++ptr;
}
} else return false; /* missing expected digit */
} else return false; /* empty string or loose '-' */
if (ptr < end && val[ptr] == '.')
{
++ptr;
if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9')
{
while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
return false; /* overflow */
++ptr;
++point_ofs;
}
} else return false; /* missing expected digit */
}
if (ptr < end && (val[ptr] == 'e' || val[ptr] == 'E'))
{
++ptr;
if (ptr < end && val[ptr] == '+')
++ptr;
else if (ptr < end && val[ptr] == '-') {
exponent_sign = true;
++ptr;
}
if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
if (exponent > (UPPER_BOUND / 10LL))
return false; /* overflow */
exponent = exponent * 10 + val[ptr] - '0';
++ptr;
}
} else return false; /* missing expected digit */
}
if (ptr != end)
return false; /* trailing garbage */
/* finalize exponent */
if (exponent_sign)
exponent = -exponent;
exponent = exponent - point_ofs + mantissa_tzeros;
/* finalize mantissa */
if (mantissa_sign)
mantissa = -mantissa;
/* convert to one 64-bit fixed-point value */
exponent += decimals;
if (exponent < 0)
return false; /* cannot represent values smaller than 10^-decimals */
if (exponent >= 18)
return false; /* cannot represent values larger than or equal to 10^(18-decimals) */
for (int i=0; i < exponent; ++i) {
if (mantissa > (UPPER_BOUND / 10LL) || mantissa < -(UPPER_BOUND / 10LL))
return false; /* overflow */
mantissa *= 10;
}
if (mantissa > UPPER_BOUND || mantissa < -UPPER_BOUND)
return false; /* overflow */
if (amount_out)
*amount_out = mantissa;
return true;
}