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 #include "utilstrencodings.h"
7
8 #include "tinyformat.h"
9
10 #include <cstdlib>
11 #include <cstring>
12 #include <errno.h>
13 #include <limits>
14
15 using namespace std;
16
17 static const string CHARS_ALPHA_NUM = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
18
19 static const string SAFE_CHARS[] =
20 {
21 CHARS_ALPHA_NUM + " .,;-_/:?@()", // SAFE_CHARS_DEFAULT
22 CHARS_ALPHA_NUM + " .,;-_?@" // SAFE_CHARS_UA_COMMENT
23 };
24
SanitizeString(const string & str,int rule)25 string SanitizeString(const string& str, int rule)
26 {
27 string strResult;
28 for (std::string::size_type i = 0; i < str.size(); i++)
29 {
30 if (SAFE_CHARS[rule].find(str[i]) != std::string::npos)
31 strResult.push_back(str[i]);
32 }
33 return strResult;
34 }
35
36 const signed char p_util_hexdigit[256] =
37 { -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
38 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
39 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
40 0,1,2,3,4,5,6,7,8,9,-1,-1,-1,-1,-1,-1,
41 -1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
42 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
43 -1,0xa,0xb,0xc,0xd,0xe,0xf,-1,-1,-1,-1,-1,-1,-1,-1,-1,
44 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
45 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
46 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
47 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
48 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
49 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
50 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
51 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
52 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, };
53
HexDigit(char c)54 signed char HexDigit(char c)
55 {
56 return p_util_hexdigit[(unsigned char)c];
57 }
58
IsHex(const string & str)59 bool IsHex(const string& str)
60 {
61 for(std::string::const_iterator it(str.begin()); it != str.end(); ++it)
62 {
63 if (HexDigit(*it) < 0)
64 return false;
65 }
66 return (str.size() > 0) && (str.size()%2 == 0);
67 }
68
ParseHex(const char * psz)69 vector<unsigned char> ParseHex(const char* psz)
70 {
71 // convert hex dump to vector
72 vector<unsigned char> vch;
73 while (true)
74 {
75 while (isspace(*psz))
76 psz++;
77 signed char c = HexDigit(*psz++);
78 if (c == (signed char)-1)
79 break;
80 unsigned char n = (c << 4);
81 c = HexDigit(*psz++);
82 if (c == (signed char)-1)
83 break;
84 n |= c;
85 vch.push_back(n);
86 }
87 return vch;
88 }
89
ParseHex(const string & str)90 vector<unsigned char> ParseHex(const string& str)
91 {
92 return ParseHex(str.c_str());
93 }
94
EncodeBase64(const unsigned char * pch,size_t len)95 string EncodeBase64(const unsigned char* pch, size_t len)
96 {
97 static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
98
99 string strRet="";
100 strRet.reserve((len+2)/3*4);
101
102 int mode=0, left=0;
103 const unsigned char *pchEnd = pch+len;
104
105 while (pch<pchEnd)
106 {
107 int enc = *(pch++);
108 switch (mode)
109 {
110 case 0: // we have no bits
111 strRet += pbase64[enc >> 2];
112 left = (enc & 3) << 4;
113 mode = 1;
114 break;
115
116 case 1: // we have two bits
117 strRet += pbase64[left | (enc >> 4)];
118 left = (enc & 15) << 2;
119 mode = 2;
120 break;
121
122 case 2: // we have four bits
123 strRet += pbase64[left | (enc >> 6)];
124 strRet += pbase64[enc & 63];
125 mode = 0;
126 break;
127 }
128 }
129
130 if (mode)
131 {
132 strRet += pbase64[left];
133 strRet += '=';
134 if (mode == 1)
135 strRet += '=';
136 }
137
138 return strRet;
139 }
140
EncodeBase64(const string & str)141 string EncodeBase64(const string& str)
142 {
143 return EncodeBase64((const unsigned char*)str.c_str(), str.size());
144 }
145
DecodeBase64(const char * p,bool * pfInvalid)146 vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
147 {
148 static const int decode64_table[256] =
149 {
150 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
151 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
152 -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1,
153 -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
154 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28,
155 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
156 49, 50, 51, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
157 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
158 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
159 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
160 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
161 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
162 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
163 };
164
165 if (pfInvalid)
166 *pfInvalid = false;
167
168 vector<unsigned char> vchRet;
169 vchRet.reserve(strlen(p)*3/4);
170
171 int mode = 0;
172 int left = 0;
173
174 while (1)
175 {
176 int dec = decode64_table[(unsigned char)*p];
177 if (dec == -1) break;
178 p++;
179 switch (mode)
180 {
181 case 0: // we have no bits and get 6
182 left = dec;
183 mode = 1;
184 break;
185
186 case 1: // we have 6 bits and keep 4
187 vchRet.push_back((left<<2) | (dec>>4));
188 left = dec & 15;
189 mode = 2;
190 break;
191
192 case 2: // we have 4 bits and get 6, we keep 2
193 vchRet.push_back((left<<4) | (dec>>2));
194 left = dec & 3;
195 mode = 3;
196 break;
197
198 case 3: // we have 2 bits and get 6
199 vchRet.push_back((left<<6) | dec);
200 mode = 0;
201 break;
202 }
203 }
204
205 if (pfInvalid)
206 switch (mode)
207 {
208 case 0: // 4n base64 characters processed: ok
209 break;
210
211 case 1: // 4n+1 base64 character processed: impossible
212 *pfInvalid = true;
213 break;
214
215 case 2: // 4n+2 base64 characters processed: require '=='
216 if (left || p[0] != '=' || p[1] != '=' || decode64_table[(unsigned char)p[2]] != -1)
217 *pfInvalid = true;
218 break;
219
220 case 3: // 4n+3 base64 characters processed: require '='
221 if (left || p[0] != '=' || decode64_table[(unsigned char)p[1]] != -1)
222 *pfInvalid = true;
223 break;
224 }
225
226 return vchRet;
227 }
228
DecodeBase64(const string & str)229 string DecodeBase64(const string& str)
230 {
231 vector<unsigned char> vchRet = DecodeBase64(str.c_str());
232 return (vchRet.size() == 0) ? string() : string((const char*)&vchRet[0], vchRet.size());
233 }
234
EncodeBase32(const unsigned char * pch,size_t len)235 string EncodeBase32(const unsigned char* pch, size_t len)
236 {
237 static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
238
239 string strRet="";
240 strRet.reserve((len+4)/5*8);
241
242 int mode=0, left=0;
243 const unsigned char *pchEnd = pch+len;
244
245 while (pch<pchEnd)
246 {
247 int enc = *(pch++);
248 switch (mode)
249 {
250 case 0: // we have no bits
251 strRet += pbase32[enc >> 3];
252 left = (enc & 7) << 2;
253 mode = 1;
254 break;
255
256 case 1: // we have three bits
257 strRet += pbase32[left | (enc >> 6)];
258 strRet += pbase32[(enc >> 1) & 31];
259 left = (enc & 1) << 4;
260 mode = 2;
261 break;
262
263 case 2: // we have one bit
264 strRet += pbase32[left | (enc >> 4)];
265 left = (enc & 15) << 1;
266 mode = 3;
267 break;
268
269 case 3: // we have four bits
270 strRet += pbase32[left | (enc >> 7)];
271 strRet += pbase32[(enc >> 2) & 31];
272 left = (enc & 3) << 3;
273 mode = 4;
274 break;
275
276 case 4: // we have two bits
277 strRet += pbase32[left | (enc >> 5)];
278 strRet += pbase32[enc & 31];
279 mode = 0;
280 }
281 }
282
283 static const int nPadding[5] = {0, 6, 4, 3, 1};
284 if (mode)
285 {
286 strRet += pbase32[left];
287 for (int n=0; n<nPadding[mode]; n++)
288 strRet += '=';
289 }
290
291 return strRet;
292 }
293
EncodeBase32(const string & str)294 string EncodeBase32(const string& str)
295 {
296 return EncodeBase32((const unsigned char*)str.c_str(), str.size());
297 }
298
DecodeBase32(const char * p,bool * pfInvalid)299 vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
300 {
301 static const int decode32_table[256] =
302 {
303 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
304 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
305 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1,
306 -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
307 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 0, 1, 2,
308 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
309 23, 24, 25, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
310 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
311 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
312 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
313 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
314 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
315 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
316 };
317
318 if (pfInvalid)
319 *pfInvalid = false;
320
321 vector<unsigned char> vchRet;
322 vchRet.reserve((strlen(p))*5/8);
323
324 int mode = 0;
325 int left = 0;
326
327 while (1)
328 {
329 int dec = decode32_table[(unsigned char)*p];
330 if (dec == -1) break;
331 p++;
332 switch (mode)
333 {
334 case 0: // we have no bits and get 5
335 left = dec;
336 mode = 1;
337 break;
338
339 case 1: // we have 5 bits and keep 2
340 vchRet.push_back((left<<3) | (dec>>2));
341 left = dec & 3;
342 mode = 2;
343 break;
344
345 case 2: // we have 2 bits and keep 7
346 left = left << 5 | dec;
347 mode = 3;
348 break;
349
350 case 3: // we have 7 bits and keep 4
351 vchRet.push_back((left<<1) | (dec>>4));
352 left = dec & 15;
353 mode = 4;
354 break;
355
356 case 4: // we have 4 bits, and keep 1
357 vchRet.push_back((left<<4) | (dec>>1));
358 left = dec & 1;
359 mode = 5;
360 break;
361
362 case 5: // we have 1 bit, and keep 6
363 left = left << 5 | dec;
364 mode = 6;
365 break;
366
367 case 6: // we have 6 bits, and keep 3
368 vchRet.push_back((left<<2) | (dec>>3));
369 left = dec & 7;
370 mode = 7;
371 break;
372
373 case 7: // we have 3 bits, and keep 0
374 vchRet.push_back((left<<5) | dec);
375 mode = 0;
376 break;
377 }
378 }
379
380 if (pfInvalid)
381 switch (mode)
382 {
383 case 0: // 8n base32 characters processed: ok
384 break;
385
386 case 1: // 8n+1 base32 characters processed: impossible
387 case 3: // +3
388 case 6: // +6
389 *pfInvalid = true;
390 break;
391
392 case 2: // 8n+2 base32 characters processed: require '======'
393 if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || p[4] != '=' || p[5] != '=' || decode32_table[(unsigned char)p[6]] != -1)
394 *pfInvalid = true;
395 break;
396
397 case 4: // 8n+4 base32 characters processed: require '===='
398 if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || decode32_table[(unsigned char)p[4]] != -1)
399 *pfInvalid = true;
400 break;
401
402 case 5: // 8n+5 base32 characters processed: require '==='
403 if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || decode32_table[(unsigned char)p[3]] != -1)
404 *pfInvalid = true;
405 break;
406
407 case 7: // 8n+7 base32 characters processed: require '='
408 if (left || p[0] != '=' || decode32_table[(unsigned char)p[1]] != -1)
409 *pfInvalid = true;
410 break;
411 }
412
413 return vchRet;
414 }
415
DecodeBase32(const string & str)416 string DecodeBase32(const string& str)
417 {
418 vector<unsigned char> vchRet = DecodeBase32(str.c_str());
419 return (vchRet.size() == 0) ? string() : string((const char*)&vchRet[0], vchRet.size());
420 }
421
ParsePrechecks(const std::string & str)422 static bool ParsePrechecks(const std::string& str)
423 {
424 if (str.empty()) // No empty string allowed
425 return false;
426 if (str.size() >= 1 && (isspace(str[0]) || isspace(str[str.size()-1]))) // No padding allowed
427 return false;
428 if (str.size() != strlen(str.c_str())) // No embedded NUL characters allowed
429 return false;
430 return true;
431 }
432
ParseInt32(const std::string & str,int32_t * out)433 bool ParseInt32(const std::string& str, int32_t *out)
434 {
435 if (!ParsePrechecks(str))
436 return false;
437 char *endp = NULL;
438 errno = 0; // strtol will not set errno if valid
439 long int n = strtol(str.c_str(), &endp, 10);
440 if(out) *out = (int32_t)n;
441 // Note that strtol returns a *long int*, so even if strtol doesn't report a over/underflow
442 // we still have to check that the returned value is within the range of an *int32_t*. On 64-bit
443 // platforms the size of these types may be different.
444 return endp && *endp == 0 && !errno &&
445 n >= std::numeric_limits<int32_t>::min() &&
446 n <= std::numeric_limits<int32_t>::max();
447 }
448
ParseInt64(const std::string & str,int64_t * out)449 bool ParseInt64(const std::string& str, int64_t *out)
450 {
451 if (!ParsePrechecks(str))
452 return false;
453 char *endp = NULL;
454 errno = 0; // strtoll will not set errno if valid
455 long long int n = strtoll(str.c_str(), &endp, 10);
456 if(out) *out = (int64_t)n;
457 // Note that strtoll returns a *long long int*, so even if strtol doesn't report a over/underflow
458 // we still have to check that the returned value is within the range of an *int64_t*.
459 return endp && *endp == 0 && !errno &&
460 n >= std::numeric_limits<int64_t>::min() &&
461 n <= std::numeric_limits<int64_t>::max();
462 }
463
ParseUInt32(const std::string & str,uint32_t * out)464 bool ParseUInt32(const std::string& str, uint32_t *out)
465 {
466 if (!ParsePrechecks(str))
467 return false;
468 if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoul accepts these by default if they fit in the range
469 return false;
470 char *endp = NULL;
471 errno = 0; // strtoul will not set errno if valid
472 unsigned long int n = strtoul(str.c_str(), &endp, 10);
473 if(out) *out = (uint32_t)n;
474 // Note that strtoul returns a *unsigned long int*, so even if it doesn't report a over/underflow
475 // we still have to check that the returned value is within the range of an *uint32_t*. On 64-bit
476 // platforms the size of these types may be different.
477 return endp && *endp == 0 && !errno &&
478 n <= std::numeric_limits<uint32_t>::max();
479 }
480
ParseUInt64(const std::string & str,uint64_t * out)481 bool ParseUInt64(const std::string& str, uint64_t *out)
482 {
483 if (!ParsePrechecks(str))
484 return false;
485 if (str.size() >= 1 && str[0] == '-') // Reject negative values, unfortunately strtoull accepts these by default if they fit in the range
486 return false;
487 char *endp = NULL;
488 errno = 0; // strtoull will not set errno if valid
489 unsigned long long int n = strtoull(str.c_str(), &endp, 10);
490 if(out) *out = (uint64_t)n;
491 // Note that strtoull returns a *unsigned long long int*, so even if it doesn't report a over/underflow
492 // we still have to check that the returned value is within the range of an *uint64_t*.
493 return endp && *endp == 0 && !errno &&
494 n <= std::numeric_limits<uint64_t>::max();
495 }
496
497
ParseDouble(const std::string & str,double * out)498 bool ParseDouble(const std::string& str, double *out)
499 {
500 if (!ParsePrechecks(str))
501 return false;
502 if (str.size() >= 2 && str[0] == '0' && str[1] == 'x') // No hexadecimal floats allowed
503 return false;
504 std::istringstream text(str);
505 text.imbue(std::locale::classic());
506 double result;
507 text >> result;
508 if(out) *out = result;
509 return text.eof() && !text.fail();
510 }
511
FormatParagraph(const std::string & in,size_t width,size_t indent)512 std::string FormatParagraph(const std::string& in, size_t width, size_t indent)
513 {
514 std::stringstream out;
515 size_t ptr = 0;
516 size_t indented = 0;
517 while (ptr < in.size())
518 {
519 size_t lineend = in.find_first_of('\n', ptr);
520 if (lineend == std::string::npos) {
521 lineend = in.size();
522 }
523 const size_t linelen = lineend - ptr;
524 const size_t rem_width = width - indented;
525 if (linelen <= rem_width) {
526 out << in.substr(ptr, linelen + 1);
527 ptr = lineend + 1;
528 indented = 0;
529 } else {
530 size_t finalspace = in.find_last_of(" \n", ptr + rem_width);
531 if (finalspace == std::string::npos || finalspace < ptr) {
532 // No place to break; just include the entire word and move on
533 finalspace = in.find_first_of("\n ", ptr);
534 if (finalspace == std::string::npos) {
535 // End of the string, just add it and break
536 out << in.substr(ptr);
537 break;
538 }
539 }
540 out << in.substr(ptr, finalspace - ptr) << "\n";
541 if (in[finalspace] == '\n') {
542 indented = 0;
543 } else if (indent) {
544 out << std::string(indent, ' ');
545 indented = indent;
546 }
547 ptr = finalspace + 1;
548 }
549 }
550 return out.str();
551 }
552
i64tostr(int64_t n)553 std::string i64tostr(int64_t n)
554 {
555 return strprintf("%d", n);
556 }
557
itostr(int n)558 std::string itostr(int n)
559 {
560 return strprintf("%d", n);
561 }
562
atoi64(const char * psz)563 int64_t atoi64(const char* psz)
564 {
565 #ifdef _MSC_VER
566 return _atoi64(psz);
567 #else
568 return strtoll(psz, NULL, 10);
569 #endif
570 }
571
atoi64(const std::string & str)572 int64_t atoi64(const std::string& str)
573 {
574 #ifdef _MSC_VER
575 return _atoi64(str.c_str());
576 #else
577 return strtoll(str.c_str(), NULL, 10);
578 #endif
579 }
580
atoi(const std::string & str)581 int atoi(const std::string& str)
582 {
583 return atoi(str.c_str());
584 }
585
586 /** Upper bound for mantissa.
587 * 10^18-1 is the largest arbitrary decimal that will fit in a signed 64-bit integer.
588 * Larger integers cannot consist of arbitrary combinations of 0-9:
589 *
590 * 999999999999999999 1^18-1
591 * 9223372036854775807 (1<<63)-1 (max int64_t)
592 * 9999999999999999999 1^19-1 (would overflow)
593 */
594 static const int64_t UPPER_BOUND = 1000000000000000000LL - 1LL;
595
596 /** Helper function for ParseFixedPoint */
ProcessMantissaDigit(char ch,int64_t & mantissa,int & mantissa_tzeros)597 static inline bool ProcessMantissaDigit(char ch, int64_t &mantissa, int &mantissa_tzeros)
598 {
599 if(ch == '0')
600 ++mantissa_tzeros;
601 else {
602 for (int i=0; i<=mantissa_tzeros; ++i) {
603 if (mantissa > (UPPER_BOUND / 10LL))
604 return false; /* overflow */
605 mantissa *= 10;
606 }
607 mantissa += ch - '0';
608 mantissa_tzeros = 0;
609 }
610 return true;
611 }
612
ParseFixedPoint(const std::string & val,int decimals,int64_t * amount_out)613 bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out)
614 {
615 int64_t mantissa = 0;
616 int64_t exponent = 0;
617 int mantissa_tzeros = 0;
618 bool mantissa_sign = false;
619 bool exponent_sign = false;
620 int ptr = 0;
621 int end = val.size();
622 int point_ofs = 0;
623
624 if (ptr < end && val[ptr] == '-') {
625 mantissa_sign = true;
626 ++ptr;
627 }
628 if (ptr < end)
629 {
630 if (val[ptr] == '0') {
631 /* pass single 0 */
632 ++ptr;
633 } else if (val[ptr] >= '1' && val[ptr] <= '9') {
634 while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
635 if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
636 return false; /* overflow */
637 ++ptr;
638 }
639 } else return false; /* missing expected digit */
640 } else return false; /* empty string or loose '-' */
641 if (ptr < end && val[ptr] == '.')
642 {
643 ++ptr;
644 if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9')
645 {
646 while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
647 if (!ProcessMantissaDigit(val[ptr], mantissa, mantissa_tzeros))
648 return false; /* overflow */
649 ++ptr;
650 ++point_ofs;
651 }
652 } else return false; /* missing expected digit */
653 }
654 if (ptr < end && (val[ptr] == 'e' || val[ptr] == 'E'))
655 {
656 ++ptr;
657 if (ptr < end && val[ptr] == '+')
658 ++ptr;
659 else if (ptr < end && val[ptr] == '-') {
660 exponent_sign = true;
661 ++ptr;
662 }
663 if (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
664 while (ptr < end && val[ptr] >= '0' && val[ptr] <= '9') {
665 if (exponent > (UPPER_BOUND / 10LL))
666 return false; /* overflow */
667 exponent = exponent * 10 + val[ptr] - '0';
668 ++ptr;
669 }
670 } else return false; /* missing expected digit */
671 }
672 if (ptr != end)
673 return false; /* trailing garbage */
674
675 /* finalize exponent */
676 if (exponent_sign)
677 exponent = -exponent;
678 exponent = exponent - point_ofs + mantissa_tzeros;
679
680 /* finalize mantissa */
681 if (mantissa_sign)
682 mantissa = -mantissa;
683
684 /* convert to one 64-bit fixed-point value */
685 exponent += decimals;
686 if (exponent < 0)
687 return false; /* cannot represent values smaller than 10^-decimals */
688 if (exponent >= 18)
689 return false; /* cannot represent values larger than or equal to 10^(18-decimals) */
690
691 for (int i=0; i < exponent; ++i) {
692 if (mantissa > (UPPER_BOUND / 10LL) || mantissa < -(UPPER_BOUND / 10LL))
693 return false; /* overflow */
694 mantissa *= 10;
695 }
696 if (mantissa > UPPER_BOUND || mantissa < -UPPER_BOUND)
697 return false; /* overflow */
698
699 if (amount_out)
700 *amount_out = mantissa;
701
702 return true;
703 }
704
705