1 /* 2 ** 2001 September 15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** Utility functions used throughout sqlite. 13 ** 14 ** This file contains functions for allocating memory, comparing 15 ** strings, and stuff like that. 16 ** 17 */ 18 #include "sqliteInt.h" 19 #include <stdarg.h> 20 #if HAVE_ISNAN || SQLITE_HAVE_ISNAN 21 # include <math.h> 22 #endif 23 24 /* 25 ** Routine needed to support the testcase() macro. 26 */ 27 #ifdef SQLITE_COVERAGE_TEST 28 void sqlite3Coverage(int x){ 29 static unsigned dummy = 0; 30 dummy += (unsigned)x; 31 } 32 #endif 33 34 /* 35 ** Give a callback to the test harness that can be used to simulate faults 36 ** in places where it is difficult or expensive to do so purely by means 37 ** of inputs. 38 ** 39 ** The intent of the integer argument is to let the fault simulator know 40 ** which of multiple sqlite3FaultSim() calls has been hit. 41 ** 42 ** Return whatever integer value the test callback returns, or return 43 ** SQLITE_OK if no test callback is installed. 44 */ 45 #ifndef SQLITE_OMIT_BUILTIN_TEST 46 int sqlite3FaultSim(int iTest){ 47 int (*xCallback)(int) = sqlite3GlobalConfig.xTestCallback; 48 return xCallback ? xCallback(iTest) : SQLITE_OK; 49 } 50 #endif 51 52 #ifndef SQLITE_OMIT_FLOATING_POINT 53 /* 54 ** Return true if the floating point value is Not a Number (NaN). 55 ** 56 ** Use the math library isnan() function if compiled with SQLITE_HAVE_ISNAN. 57 ** Otherwise, we have our own implementation that works on most systems. 58 */ 59 int sqlite3IsNaN(double x){ 60 int rc; /* The value return */ 61 #if !SQLITE_HAVE_ISNAN && !HAVE_ISNAN 62 /* 63 ** Systems that support the isnan() library function should probably 64 ** make use of it by compiling with -DSQLITE_HAVE_ISNAN. But we have 65 ** found that many systems do not have a working isnan() function so 66 ** this implementation is provided as an alternative. 67 ** 68 ** This NaN test sometimes fails if compiled on GCC with -ffast-math. 69 ** On the other hand, the use of -ffast-math comes with the following 70 ** warning: 71 ** 72 ** This option [-ffast-math] should never be turned on by any 73 ** -O option since it can result in incorrect output for programs 74 ** which depend on an exact implementation of IEEE or ISO 75 ** rules/specifications for math functions. 76 ** 77 ** Under MSVC, this NaN test may fail if compiled with a floating- 78 ** point precision mode other than /fp:precise. From the MSDN 79 ** documentation: 80 ** 81 ** The compiler [with /fp:precise] will properly handle comparisons 82 ** involving NaN. For example, x != x evaluates to true if x is NaN 83 ** ... 84 */ 85 #ifdef __FAST_MATH__ 86 # error SQLite will not work correctly with the -ffast-math option of GCC. 87 #endif 88 volatile double y = x; 89 volatile double z = y; 90 rc = (y!=z); 91 #else /* if HAVE_ISNAN */ 92 rc = isnan(x); 93 #endif /* HAVE_ISNAN */ 94 testcase( rc ); 95 return rc; 96 } 97 #endif /* SQLITE_OMIT_FLOATING_POINT */ 98 99 /* 100 ** Compute a string length that is limited to what can be stored in 101 ** lower 30 bits of a 32-bit signed integer. 102 ** 103 ** The value returned will never be negative. Nor will it ever be greater 104 ** than the actual length of the string. For very long strings (greater 105 ** than 1GiB) the value returned might be less than the true string length. 106 */ 107 int sqlite3Strlen30(const char *z){ 108 if( z==0 ) return 0; 109 return 0x3fffffff & (int)strlen(z); 110 } 111 112 /* 113 ** Return the declared type of a column. Or return zDflt if the column 114 ** has no declared type. 115 ** 116 ** The column type is an extra string stored after the zero-terminator on 117 ** the column name if and only if the COLFLAG_HASTYPE flag is set. 118 */ 119 char *sqlite3ColumnType(Column *pCol, char *zDflt){ 120 if( (pCol->colFlags & COLFLAG_HASTYPE)==0 ) return zDflt; 121 return pCol->zName + strlen(pCol->zName) + 1; 122 } 123 124 /* 125 ** Helper function for sqlite3Error() - called rarely. Broken out into 126 ** a separate routine to avoid unnecessary register saves on entry to 127 ** sqlite3Error(). 128 */ 129 static SQLITE_NOINLINE void sqlite3ErrorFinish(sqlite3 *db, int err_code){ 130 if( db->pErr ) sqlite3ValueSetNull(db->pErr); 131 sqlite3SystemError(db, err_code); 132 } 133 134 /* 135 ** Set the current error code to err_code and clear any prior error message. 136 ** Also set iSysErrno (by calling sqlite3System) if the err_code indicates 137 ** that would be appropriate. 138 */ 139 void sqlite3Error(sqlite3 *db, int err_code){ 140 assert( db!=0 ); 141 db->errCode = err_code; 142 if( err_code || db->pErr ) sqlite3ErrorFinish(db, err_code); 143 } 144 145 /* 146 ** Load the sqlite3.iSysErrno field if that is an appropriate thing 147 ** to do based on the SQLite error code in rc. 148 */ 149 void sqlite3SystemError(sqlite3 *db, int rc){ 150 if( rc==SQLITE_IOERR_NOMEM ) return; 151 rc &= 0xff; 152 if( rc==SQLITE_CANTOPEN || rc==SQLITE_IOERR ){ 153 db->iSysErrno = sqlite3OsGetLastError(db->pVfs); 154 } 155 } 156 157 /* 158 ** Set the most recent error code and error string for the sqlite 159 ** handle "db". The error code is set to "err_code". 160 ** 161 ** If it is not NULL, string zFormat specifies the format of the 162 ** error string in the style of the printf functions: The following 163 ** format characters are allowed: 164 ** 165 ** %s Insert a string 166 ** %z A string that should be freed after use 167 ** %d Insert an integer 168 ** %T Insert a token 169 ** %S Insert the first element of a SrcList 170 ** 171 ** zFormat and any string tokens that follow it are assumed to be 172 ** encoded in UTF-8. 173 ** 174 ** To clear the most recent error for sqlite handle "db", sqlite3Error 175 ** should be called with err_code set to SQLITE_OK and zFormat set 176 ** to NULL. 177 */ 178 void sqlite3ErrorWithMsg(sqlite3 *db, int err_code, const char *zFormat, ...){ 179 assert( db!=0 ); 180 db->errCode = err_code; 181 sqlite3SystemError(db, err_code); 182 if( zFormat==0 ){ 183 sqlite3Error(db, err_code); 184 }else if( db->pErr || (db->pErr = sqlite3ValueNew(db))!=0 ){ 185 char *z; 186 va_list ap; 187 va_start(ap, zFormat); 188 z = sqlite3VMPrintf(db, zFormat, ap); 189 va_end(ap); 190 sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC); 191 } 192 } 193 194 /* 195 ** Add an error message to pParse->zErrMsg and increment pParse->nErr. 196 ** The following formatting characters are allowed: 197 ** 198 ** %s Insert a string 199 ** %z A string that should be freed after use 200 ** %d Insert an integer 201 ** %T Insert a token 202 ** %S Insert the first element of a SrcList 203 ** 204 ** This function should be used to report any error that occurs while 205 ** compiling an SQL statement (i.e. within sqlite3_prepare()). The 206 ** last thing the sqlite3_prepare() function does is copy the error 207 ** stored by this function into the database handle using sqlite3Error(). 208 ** Functions sqlite3Error() or sqlite3ErrorWithMsg() should be used 209 ** during statement execution (sqlite3_step() etc.). 210 */ 211 void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){ 212 char *zMsg; 213 va_list ap; 214 sqlite3 *db = pParse->db; 215 va_start(ap, zFormat); 216 zMsg = sqlite3VMPrintf(db, zFormat, ap); 217 va_end(ap); 218 if( db->suppressErr ){ 219 sqlite3DbFree(db, zMsg); 220 }else{ 221 pParse->nErr++; 222 sqlite3DbFree(db, pParse->zErrMsg); 223 pParse->zErrMsg = zMsg; 224 pParse->rc = SQLITE_ERROR; 225 } 226 } 227 228 /* 229 ** Convert an SQL-style quoted string into a normal string by removing 230 ** the quote characters. The conversion is done in-place. If the 231 ** input does not begin with a quote character, then this routine 232 ** is a no-op. 233 ** 234 ** The input string must be zero-terminated. A new zero-terminator 235 ** is added to the dequoted string. 236 ** 237 ** The return value is -1 if no dequoting occurs or the length of the 238 ** dequoted string, exclusive of the zero terminator, if dequoting does 239 ** occur. 240 ** 241 ** 2002-Feb-14: This routine is extended to remove MS-Access style 242 ** brackets from around identifiers. For example: "[a-b-c]" becomes 243 ** "a-b-c". 244 */ 245 void sqlite3Dequote(char *z){ 246 char quote; 247 int i, j; 248 if( z==0 ) return; 249 quote = z[0]; 250 if( !sqlite3Isquote(quote) ) return; 251 if( quote=='[' ) quote = ']'; 252 for(i=1, j=0;; i++){ 253 assert( z[i] ); 254 if( z[i]==quote ){ 255 if( z[i+1]==quote ){ 256 z[j++] = quote; 257 i++; 258 }else{ 259 break; 260 } 261 }else{ 262 z[j++] = z[i]; 263 } 264 } 265 z[j] = 0; 266 } 267 268 /* 269 ** Generate a Token object from a string 270 */ 271 void sqlite3TokenInit(Token *p, char *z){ 272 p->z = z; 273 p->n = sqlite3Strlen30(z); 274 } 275 276 /* Convenient short-hand */ 277 #define UpperToLower sqlite3UpperToLower 278 279 /* 280 ** Some systems have stricmp(). Others have strcasecmp(). Because 281 ** there is no consistency, we will define our own. 282 ** 283 ** IMPLEMENTATION-OF: R-30243-02494 The sqlite3_stricmp() and 284 ** sqlite3_strnicmp() APIs allow applications and extensions to compare 285 ** the contents of two buffers containing UTF-8 strings in a 286 ** case-independent fashion, using the same definition of "case 287 ** independence" that SQLite uses internally when comparing identifiers. 288 */ 289 int sqlite3_stricmp(const char *zLeft, const char *zRight){ 290 if( zLeft==0 ){ 291 return zRight ? -1 : 0; 292 }else if( zRight==0 ){ 293 return 1; 294 } 295 return sqlite3StrICmp(zLeft, zRight); 296 } 297 int sqlite3StrICmp(const char *zLeft, const char *zRight){ 298 unsigned char *a, *b; 299 int c; 300 a = (unsigned char *)zLeft; 301 b = (unsigned char *)zRight; 302 for(;;){ 303 c = (int)UpperToLower[*a] - (int)UpperToLower[*b]; 304 if( c || *a==0 ) break; 305 a++; 306 b++; 307 } 308 return c; 309 } 310 int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){ 311 register unsigned char *a, *b; 312 if( zLeft==0 ){ 313 return zRight ? -1 : 0; 314 }else if( zRight==0 ){ 315 return 1; 316 } 317 a = (unsigned char *)zLeft; 318 b = (unsigned char *)zRight; 319 while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; } 320 return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b]; 321 } 322 323 /* 324 ** The string z[] is an text representation of a real number. 325 ** Convert this string to a double and write it into *pResult. 326 ** 327 ** The string z[] is length bytes in length (bytes, not characters) and 328 ** uses the encoding enc. The string is not necessarily zero-terminated. 329 ** 330 ** Return TRUE if the result is a valid real number (or integer) and FALSE 331 ** if the string is empty or contains extraneous text. Valid numbers 332 ** are in one of these formats: 333 ** 334 ** [+-]digits[E[+-]digits] 335 ** [+-]digits.[digits][E[+-]digits] 336 ** [+-].digits[E[+-]digits] 337 ** 338 ** Leading and trailing whitespace is ignored for the purpose of determining 339 ** validity. 340 ** 341 ** If some prefix of the input string is a valid number, this routine 342 ** returns FALSE but it still converts the prefix and writes the result 343 ** into *pResult. 344 */ 345 int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){ 346 #ifndef SQLITE_OMIT_FLOATING_POINT 347 int incr; 348 const char *zEnd = z + length; 349 /* sign * significand * (10 ^ (esign * exponent)) */ 350 int sign = 1; /* sign of significand */ 351 i64 s = 0; /* significand */ 352 int d = 0; /* adjust exponent for shifting decimal point */ 353 int esign = 1; /* sign of exponent */ 354 int e = 0; /* exponent */ 355 int eValid = 1; /* True exponent is either not used or is well-formed */ 356 double result; 357 int nDigits = 0; 358 int nonNum = 0; /* True if input contains UTF16 with high byte non-zero */ 359 360 assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE ); 361 *pResult = 0.0; /* Default return value, in case of an error */ 362 363 if( enc==SQLITE_UTF8 ){ 364 incr = 1; 365 }else{ 366 int i; 367 incr = 2; 368 assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 ); 369 for(i=3-enc; i<length && z[i]==0; i+=2){} 370 nonNum = i<length; 371 zEnd = &z[i^1]; 372 z += (enc&1); 373 } 374 375 /* skip leading spaces */ 376 while( z<zEnd && sqlite3Isspace(*z) ) z+=incr; 377 if( z>=zEnd ) return 0; 378 379 /* get sign of significand */ 380 if( *z=='-' ){ 381 sign = -1; 382 z+=incr; 383 }else if( *z=='+' ){ 384 z+=incr; 385 } 386 387 /* copy max significant digits to significand */ 388 while( z<zEnd && sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){ 389 s = s*10 + (*z - '0'); 390 z+=incr, nDigits++; 391 } 392 393 /* skip non-significant significand digits 394 ** (increase exponent by d to shift decimal left) */ 395 while( z<zEnd && sqlite3Isdigit(*z) ) z+=incr, nDigits++, d++; 396 if( z>=zEnd ) goto do_atof_calc; 397 398 /* if decimal point is present */ 399 if( *z=='.' ){ 400 z+=incr; 401 /* copy digits from after decimal to significand 402 ** (decrease exponent by d to shift decimal right) */ 403 while( z<zEnd && sqlite3Isdigit(*z) ){ 404 if( s<((LARGEST_INT64-9)/10) ){ 405 s = s*10 + (*z - '0'); 406 d--; 407 } 408 z+=incr, nDigits++; 409 } 410 } 411 if( z>=zEnd ) goto do_atof_calc; 412 413 /* if exponent is present */ 414 if( *z=='e' || *z=='E' ){ 415 z+=incr; 416 eValid = 0; 417 418 /* This branch is needed to avoid a (harmless) buffer overread. The 419 ** special comment alerts the mutation tester that the correct answer 420 ** is obtained even if the branch is omitted */ 421 if( z>=zEnd ) goto do_atof_calc; /*PREVENTS-HARMLESS-OVERREAD*/ 422 423 /* get sign of exponent */ 424 if( *z=='-' ){ 425 esign = -1; 426 z+=incr; 427 }else if( *z=='+' ){ 428 z+=incr; 429 } 430 /* copy digits to exponent */ 431 while( z<zEnd && sqlite3Isdigit(*z) ){ 432 e = e<10000 ? (e*10 + (*z - '0')) : 10000; 433 z+=incr; 434 eValid = 1; 435 } 436 } 437 438 /* skip trailing spaces */ 439 while( z<zEnd && sqlite3Isspace(*z) ) z+=incr; 440 441 do_atof_calc: 442 /* adjust exponent by d, and update sign */ 443 e = (e*esign) + d; 444 if( e<0 ) { 445 esign = -1; 446 e *= -1; 447 } else { 448 esign = 1; 449 } 450 451 if( s==0 ) { 452 /* In the IEEE 754 standard, zero is signed. */ 453 result = sign<0 ? -(double)0 : (double)0; 454 } else { 455 /* Attempt to reduce exponent. 456 ** 457 ** Branches that are not required for the correct answer but which only 458 ** help to obtain the correct answer faster are marked with special 459 ** comments, as a hint to the mutation tester. 460 */ 461 while( e>0 ){ /*OPTIMIZATION-IF-TRUE*/ 462 if( esign>0 ){ 463 if( s>=(LARGEST_INT64/10) ) break; /*OPTIMIZATION-IF-FALSE*/ 464 s *= 10; 465 }else{ 466 if( s%10!=0 ) break; /*OPTIMIZATION-IF-FALSE*/ 467 s /= 10; 468 } 469 e--; 470 } 471 472 /* adjust the sign of significand */ 473 s = sign<0 ? -s : s; 474 475 if( e==0 ){ /*OPTIMIZATION-IF-TRUE*/ 476 result = (double)s; 477 }else{ 478 LONGDOUBLE_TYPE scale = 1.0; 479 /* attempt to handle extremely small/large numbers better */ 480 if( e>307 ){ /*OPTIMIZATION-IF-TRUE*/ 481 if( e<342 ){ /*OPTIMIZATION-IF-TRUE*/ 482 while( e%308 ) { scale *= 1.0e+1; e -= 1; } 483 if( esign<0 ){ 484 result = s / scale; 485 result /= 1.0e+308; 486 }else{ 487 result = s * scale; 488 result *= 1.0e+308; 489 } 490 }else{ assert( e>=342 ); 491 if( esign<0 ){ 492 result = 0.0*s; 493 }else{ 494 result = 1e308*1e308*s; /* Infinity */ 495 } 496 } 497 }else{ 498 /* 1.0e+22 is the largest power of 10 than can be 499 ** represented exactly. */ 500 while( e%22 ) { scale *= 1.0e+1; e -= 1; } 501 while( e>0 ) { scale *= 1.0e+22; e -= 22; } 502 if( esign<0 ){ 503 result = s / scale; 504 }else{ 505 result = s * scale; 506 } 507 } 508 } 509 } 510 511 /* store the result */ 512 *pResult = result; 513 514 /* return true if number and no extra non-whitespace chracters after */ 515 return z==zEnd && nDigits>0 && eValid && nonNum==0; 516 #else 517 return !sqlite3Atoi64(z, pResult, length, enc); 518 #endif /* SQLITE_OMIT_FLOATING_POINT */ 519 } 520 521 /* 522 ** Compare the 19-character string zNum against the text representation 523 ** value 2^63: 9223372036854775808. Return negative, zero, or positive 524 ** if zNum is less than, equal to, or greater than the string. 525 ** Note that zNum must contain exactly 19 characters. 526 ** 527 ** Unlike memcmp() this routine is guaranteed to return the difference 528 ** in the values of the last digit if the only difference is in the 529 ** last digit. So, for example, 530 ** 531 ** compare2pow63("9223372036854775800", 1) 532 ** 533 ** will return -8. 534 */ 535 static int compare2pow63(const char *zNum, int incr){ 536 int c = 0; 537 int i; 538 /* 012345678901234567 */ 539 const char *pow63 = "922337203685477580"; 540 for(i=0; c==0 && i<18; i++){ 541 c = (zNum[i*incr]-pow63[i])*10; 542 } 543 if( c==0 ){ 544 c = zNum[18*incr] - '8'; 545 testcase( c==(-1) ); 546 testcase( c==0 ); 547 testcase( c==(+1) ); 548 } 549 return c; 550 } 551 552 /* 553 ** Convert zNum to a 64-bit signed integer. zNum must be decimal. This 554 ** routine does *not* accept hexadecimal notation. 555 ** 556 ** If the zNum value is representable as a 64-bit twos-complement 557 ** integer, then write that value into *pNum and return 0. 558 ** 559 ** If zNum is exactly 9223372036854775808, return 2. This special 560 ** case is broken out because while 9223372036854775808 cannot be a 561 ** signed 64-bit integer, its negative -9223372036854775808 can be. 562 ** 563 ** If zNum is too big for a 64-bit integer and is not 564 ** 9223372036854775808 or if zNum contains any non-numeric text, 565 ** then return 1. 566 ** 567 ** length is the number of bytes in the string (bytes, not characters). 568 ** The string is not necessarily zero-terminated. The encoding is 569 ** given by enc. 570 */ 571 int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){ 572 int incr; 573 u64 u = 0; 574 int neg = 0; /* assume positive */ 575 int i; 576 int c = 0; 577 int nonNum = 0; /* True if input contains UTF16 with high byte non-zero */ 578 const char *zStart; 579 const char *zEnd = zNum + length; 580 assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE ); 581 if( enc==SQLITE_UTF8 ){ 582 incr = 1; 583 }else{ 584 incr = 2; 585 assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 ); 586 for(i=3-enc; i<length && zNum[i]==0; i+=2){} 587 nonNum = i<length; 588 zEnd = &zNum[i^1]; 589 zNum += (enc&1); 590 } 591 while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr; 592 if( zNum<zEnd ){ 593 if( *zNum=='-' ){ 594 neg = 1; 595 zNum+=incr; 596 }else if( *zNum=='+' ){ 597 zNum+=incr; 598 } 599 } 600 zStart = zNum; 601 while( zNum<zEnd && zNum[0]=='0' ){ zNum+=incr; } /* Skip leading zeros. */ 602 for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i+=incr){ 603 u = u*10 + c - '0'; 604 } 605 if( u>LARGEST_INT64 ){ 606 *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64; 607 }else if( neg ){ 608 *pNum = -(i64)u; 609 }else{ 610 *pNum = (i64)u; 611 } 612 testcase( i==18 ); 613 testcase( i==19 ); 614 testcase( i==20 ); 615 if( &zNum[i]<zEnd /* Extra bytes at the end */ 616 || (i==0 && zStart==zNum) /* No digits */ 617 || i>19*incr /* Too many digits */ 618 || nonNum /* UTF16 with high-order bytes non-zero */ 619 ){ 620 /* zNum is empty or contains non-numeric text or is longer 621 ** than 19 digits (thus guaranteeing that it is too large) */ 622 return 1; 623 }else if( i<19*incr ){ 624 /* Less than 19 digits, so we know that it fits in 64 bits */ 625 assert( u<=LARGEST_INT64 ); 626 return 0; 627 }else{ 628 /* zNum is a 19-digit numbers. Compare it against 9223372036854775808. */ 629 c = compare2pow63(zNum, incr); 630 if( c<0 ){ 631 /* zNum is less than 9223372036854775808 so it fits */ 632 assert( u<=LARGEST_INT64 ); 633 return 0; 634 }else if( c>0 ){ 635 /* zNum is greater than 9223372036854775808 so it overflows */ 636 return 1; 637 }else{ 638 /* zNum is exactly 9223372036854775808. Fits if negative. The 639 ** special case 2 overflow if positive */ 640 assert( u-1==LARGEST_INT64 ); 641 return neg ? 0 : 2; 642 } 643 } 644 } 645 646 /* 647 ** Transform a UTF-8 integer literal, in either decimal or hexadecimal, 648 ** into a 64-bit signed integer. This routine accepts hexadecimal literals, 649 ** whereas sqlite3Atoi64() does not. 650 ** 651 ** Returns: 652 ** 653 ** 0 Successful transformation. Fits in a 64-bit signed integer. 654 ** 1 Integer too large for a 64-bit signed integer or is malformed 655 ** 2 Special case of 9223372036854775808 656 */ 657 int sqlite3DecOrHexToI64(const char *z, i64 *pOut){ 658 #ifndef SQLITE_OMIT_HEX_INTEGER 659 if( z[0]=='0' 660 && (z[1]=='x' || z[1]=='X') 661 ){ 662 u64 u = 0; 663 int i, k; 664 for(i=2; z[i]=='0'; i++){} 665 for(k=i; sqlite3Isxdigit(z[k]); k++){ 666 u = u*16 + sqlite3HexToInt(z[k]); 667 } 668 memcpy(pOut, &u, 8); 669 return (z[k]==0 && k-i<=16) ? 0 : 1; 670 }else 671 #endif /* SQLITE_OMIT_HEX_INTEGER */ 672 { 673 return sqlite3Atoi64(z, pOut, sqlite3Strlen30(z), SQLITE_UTF8); 674 } 675 } 676 677 /* 678 ** If zNum represents an integer that will fit in 32-bits, then set 679 ** *pValue to that integer and return true. Otherwise return false. 680 ** 681 ** This routine accepts both decimal and hexadecimal notation for integers. 682 ** 683 ** Any non-numeric characters that following zNum are ignored. 684 ** This is different from sqlite3Atoi64() which requires the 685 ** input number to be zero-terminated. 686 */ 687 int sqlite3GetInt32(const char *zNum, int *pValue){ 688 sqlite_int64 v = 0; 689 int i, c; 690 int neg = 0; 691 if( zNum[0]=='-' ){ 692 neg = 1; 693 zNum++; 694 }else if( zNum[0]=='+' ){ 695 zNum++; 696 } 697 #ifndef SQLITE_OMIT_HEX_INTEGER 698 else if( zNum[0]=='0' 699 && (zNum[1]=='x' || zNum[1]=='X') 700 && sqlite3Isxdigit(zNum[2]) 701 ){ 702 u32 u = 0; 703 zNum += 2; 704 while( zNum[0]=='0' ) zNum++; 705 for(i=0; sqlite3Isxdigit(zNum[i]) && i<8; i++){ 706 u = u*16 + sqlite3HexToInt(zNum[i]); 707 } 708 if( (u&0x80000000)==0 && sqlite3Isxdigit(zNum[i])==0 ){ 709 memcpy(pValue, &u, 4); 710 return 1; 711 }else{ 712 return 0; 713 } 714 } 715 #endif 716 while( zNum[0]=='0' ) zNum++; 717 for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){ 718 v = v*10 + c; 719 } 720 721 /* The longest decimal representation of a 32 bit integer is 10 digits: 722 ** 723 ** 1234567890 724 ** 2^31 -> 2147483648 725 */ 726 testcase( i==10 ); 727 if( i>10 ){ 728 return 0; 729 } 730 testcase( v-neg==2147483647 ); 731 if( v-neg>2147483647 ){ 732 return 0; 733 } 734 if( neg ){ 735 v = -v; 736 } 737 *pValue = (int)v; 738 return 1; 739 } 740 741 /* 742 ** Return a 32-bit integer value extracted from a string. If the 743 ** string is not an integer, just return 0. 744 */ 745 int sqlite3Atoi(const char *z){ 746 int x = 0; 747 if( z ) sqlite3GetInt32(z, &x); 748 return x; 749 } 750 751 /* 752 ** The variable-length integer encoding is as follows: 753 ** 754 ** KEY: 755 ** A = 0xxxxxxx 7 bits of data and one flag bit 756 ** B = 1xxxxxxx 7 bits of data and one flag bit 757 ** C = xxxxxxxx 8 bits of data 758 ** 759 ** 7 bits - A 760 ** 14 bits - BA 761 ** 21 bits - BBA 762 ** 28 bits - BBBA 763 ** 35 bits - BBBBA 764 ** 42 bits - BBBBBA 765 ** 49 bits - BBBBBBA 766 ** 56 bits - BBBBBBBA 767 ** 64 bits - BBBBBBBBC 768 */ 769 770 /* 771 ** Write a 64-bit variable-length integer to memory starting at p[0]. 772 ** The length of data write will be between 1 and 9 bytes. The number 773 ** of bytes written is returned. 774 ** 775 ** A variable-length integer consists of the lower 7 bits of each byte 776 ** for all bytes that have the 8th bit set and one byte with the 8th 777 ** bit clear. Except, if we get to the 9th byte, it stores the full 778 ** 8 bits and is the last byte. 779 */ 780 static int SQLITE_NOINLINE putVarint64(unsigned char *p, u64 v){ 781 int i, j, n; 782 u8 buf[10]; 783 if( v & (((u64)0xff000000)<<32) ){ 784 p[8] = (u8)v; 785 v >>= 8; 786 for(i=7; i>=0; i--){ 787 p[i] = (u8)((v & 0x7f) | 0x80); 788 v >>= 7; 789 } 790 return 9; 791 } 792 n = 0; 793 do{ 794 buf[n++] = (u8)((v & 0x7f) | 0x80); 795 v >>= 7; 796 }while( v!=0 ); 797 buf[0] &= 0x7f; 798 assert( n<=9 ); 799 for(i=0, j=n-1; j>=0; j--, i++){ 800 p[i] = buf[j]; 801 } 802 return n; 803 } 804 int sqlite3PutVarint(unsigned char *p, u64 v){ 805 if( v<=0x7f ){ 806 p[0] = v&0x7f; 807 return 1; 808 } 809 if( v<=0x3fff ){ 810 p[0] = ((v>>7)&0x7f)|0x80; 811 p[1] = v&0x7f; 812 return 2; 813 } 814 return putVarint64(p,v); 815 } 816 817 /* 818 ** Bitmasks used by sqlite3GetVarint(). These precomputed constants 819 ** are defined here rather than simply putting the constant expressions 820 ** inline in order to work around bugs in the RVT compiler. 821 ** 822 ** SLOT_2_0 A mask for (0x7f<<14) | 0x7f 823 ** 824 ** SLOT_4_2_0 A mask for (0x7f<<28) | SLOT_2_0 825 */ 826 #define SLOT_2_0 0x001fc07f 827 #define SLOT_4_2_0 0xf01fc07f 828 829 830 /* 831 ** Read a 64-bit variable-length integer from memory starting at p[0]. 832 ** Return the number of bytes read. The value is stored in *v. 833 */ 834 u8 sqlite3GetVarint(const unsigned char *p, u64 *v){ 835 u32 a,b,s; 836 837 a = *p; 838 /* a: p0 (unmasked) */ 839 if (!(a&0x80)) 840 { 841 *v = a; 842 return 1; 843 } 844 845 p++; 846 b = *p; 847 /* b: p1 (unmasked) */ 848 if (!(b&0x80)) 849 { 850 a &= 0x7f; 851 a = a<<7; 852 a |= b; 853 *v = a; 854 return 2; 855 } 856 857 /* Verify that constants are precomputed correctly */ 858 assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) ); 859 assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) ); 860 861 p++; 862 a = a<<14; 863 a |= *p; 864 /* a: p0<<14 | p2 (unmasked) */ 865 if (!(a&0x80)) 866 { 867 a &= SLOT_2_0; 868 b &= 0x7f; 869 b = b<<7; 870 a |= b; 871 *v = a; 872 return 3; 873 } 874 875 /* CSE1 from below */ 876 a &= SLOT_2_0; 877 p++; 878 b = b<<14; 879 b |= *p; 880 /* b: p1<<14 | p3 (unmasked) */ 881 if (!(b&0x80)) 882 { 883 b &= SLOT_2_0; 884 /* moved CSE1 up */ 885 /* a &= (0x7f<<14)|(0x7f); */ 886 a = a<<7; 887 a |= b; 888 *v = a; 889 return 4; 890 } 891 892 /* a: p0<<14 | p2 (masked) */ 893 /* b: p1<<14 | p3 (unmasked) */ 894 /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ 895 /* moved CSE1 up */ 896 /* a &= (0x7f<<14)|(0x7f); */ 897 b &= SLOT_2_0; 898 s = a; 899 /* s: p0<<14 | p2 (masked) */ 900 901 p++; 902 a = a<<14; 903 a |= *p; 904 /* a: p0<<28 | p2<<14 | p4 (unmasked) */ 905 if (!(a&0x80)) 906 { 907 /* we can skip these cause they were (effectively) done above 908 ** while calculating s */ 909 /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */ 910 /* b &= (0x7f<<14)|(0x7f); */ 911 b = b<<7; 912 a |= b; 913 s = s>>18; 914 *v = ((u64)s)<<32 | a; 915 return 5; 916 } 917 918 /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ 919 s = s<<7; 920 s |= b; 921 /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ 922 923 p++; 924 b = b<<14; 925 b |= *p; 926 /* b: p1<<28 | p3<<14 | p5 (unmasked) */ 927 if (!(b&0x80)) 928 { 929 /* we can skip this cause it was (effectively) done above in calc'ing s */ 930 /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */ 931 a &= SLOT_2_0; 932 a = a<<7; 933 a |= b; 934 s = s>>18; 935 *v = ((u64)s)<<32 | a; 936 return 6; 937 } 938 939 p++; 940 a = a<<14; 941 a |= *p; 942 /* a: p2<<28 | p4<<14 | p6 (unmasked) */ 943 if (!(a&0x80)) 944 { 945 a &= SLOT_4_2_0; 946 b &= SLOT_2_0; 947 b = b<<7; 948 a |= b; 949 s = s>>11; 950 *v = ((u64)s)<<32 | a; 951 return 7; 952 } 953 954 /* CSE2 from below */ 955 a &= SLOT_2_0; 956 p++; 957 b = b<<14; 958 b |= *p; 959 /* b: p3<<28 | p5<<14 | p7 (unmasked) */ 960 if (!(b&0x80)) 961 { 962 b &= SLOT_4_2_0; 963 /* moved CSE2 up */ 964 /* a &= (0x7f<<14)|(0x7f); */ 965 a = a<<7; 966 a |= b; 967 s = s>>4; 968 *v = ((u64)s)<<32 | a; 969 return 8; 970 } 971 972 p++; 973 a = a<<15; 974 a |= *p; 975 /* a: p4<<29 | p6<<15 | p8 (unmasked) */ 976 977 /* moved CSE2 up */ 978 /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */ 979 b &= SLOT_2_0; 980 b = b<<8; 981 a |= b; 982 983 s = s<<4; 984 b = p[-4]; 985 b &= 0x7f; 986 b = b>>3; 987 s |= b; 988 989 *v = ((u64)s)<<32 | a; 990 991 return 9; 992 } 993 994 /* 995 ** Read a 32-bit variable-length integer from memory starting at p[0]. 996 ** Return the number of bytes read. The value is stored in *v. 997 ** 998 ** If the varint stored in p[0] is larger than can fit in a 32-bit unsigned 999 ** integer, then set *v to 0xffffffff. 1000 ** 1001 ** A MACRO version, getVarint32, is provided which inlines the 1002 ** single-byte case. All code should use the MACRO version as 1003 ** this function assumes the single-byte case has already been handled. 1004 */ 1005 u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){ 1006 u32 a,b; 1007 1008 /* The 1-byte case. Overwhelmingly the most common. Handled inline 1009 ** by the getVarin32() macro */ 1010 a = *p; 1011 /* a: p0 (unmasked) */ 1012 #ifndef getVarint32 1013 if (!(a&0x80)) 1014 { 1015 /* Values between 0 and 127 */ 1016 *v = a; 1017 return 1; 1018 } 1019 #endif 1020 1021 /* The 2-byte case */ 1022 p++; 1023 b = *p; 1024 /* b: p1 (unmasked) */ 1025 if (!(b&0x80)) 1026 { 1027 /* Values between 128 and 16383 */ 1028 a &= 0x7f; 1029 a = a<<7; 1030 *v = a | b; 1031 return 2; 1032 } 1033 1034 /* The 3-byte case */ 1035 p++; 1036 a = a<<14; 1037 a |= *p; 1038 /* a: p0<<14 | p2 (unmasked) */ 1039 if (!(a&0x80)) 1040 { 1041 /* Values between 16384 and 2097151 */ 1042 a &= (0x7f<<14)|(0x7f); 1043 b &= 0x7f; 1044 b = b<<7; 1045 *v = a | b; 1046 return 3; 1047 } 1048 1049 /* A 32-bit varint is used to store size information in btrees. 1050 ** Objects are rarely larger than 2MiB limit of a 3-byte varint. 1051 ** A 3-byte varint is sufficient, for example, to record the size 1052 ** of a 1048569-byte BLOB or string. 1053 ** 1054 ** We only unroll the first 1-, 2-, and 3- byte cases. The very 1055 ** rare larger cases can be handled by the slower 64-bit varint 1056 ** routine. 1057 */ 1058 #if 1 1059 { 1060 u64 v64; 1061 u8 n; 1062 1063 p -= 2; 1064 n = sqlite3GetVarint(p, &v64); 1065 assert( n>3 && n<=9 ); 1066 if( (v64 & SQLITE_MAX_U32)!=v64 ){ 1067 *v = 0xffffffff; 1068 }else{ 1069 *v = (u32)v64; 1070 } 1071 return n; 1072 } 1073 1074 #else 1075 /* For following code (kept for historical record only) shows an 1076 ** unrolling for the 3- and 4-byte varint cases. This code is 1077 ** slightly faster, but it is also larger and much harder to test. 1078 */ 1079 p++; 1080 b = b<<14; 1081 b |= *p; 1082 /* b: p1<<14 | p3 (unmasked) */ 1083 if (!(b&0x80)) 1084 { 1085 /* Values between 2097152 and 268435455 */ 1086 b &= (0x7f<<14)|(0x7f); 1087 a &= (0x7f<<14)|(0x7f); 1088 a = a<<7; 1089 *v = a | b; 1090 return 4; 1091 } 1092 1093 p++; 1094 a = a<<14; 1095 a |= *p; 1096 /* a: p0<<28 | p2<<14 | p4 (unmasked) */ 1097 if (!(a&0x80)) 1098 { 1099 /* Values between 268435456 and 34359738367 */ 1100 a &= SLOT_4_2_0; 1101 b &= SLOT_4_2_0; 1102 b = b<<7; 1103 *v = a | b; 1104 return 5; 1105 } 1106 1107 /* We can only reach this point when reading a corrupt database 1108 ** file. In that case we are not in any hurry. Use the (relatively 1109 ** slow) general-purpose sqlite3GetVarint() routine to extract the 1110 ** value. */ 1111 { 1112 u64 v64; 1113 u8 n; 1114 1115 p -= 4; 1116 n = sqlite3GetVarint(p, &v64); 1117 assert( n>5 && n<=9 ); 1118 *v = (u32)v64; 1119 return n; 1120 } 1121 #endif 1122 } 1123 1124 /* 1125 ** Return the number of bytes that will be needed to store the given 1126 ** 64-bit integer. 1127 */ 1128 int sqlite3VarintLen(u64 v){ 1129 int i; 1130 for(i=1; (v >>= 7)!=0; i++){ assert( i<10 ); } 1131 return i; 1132 } 1133 1134 1135 /* 1136 ** Read or write a four-byte big-endian integer value. 1137 */ 1138 u32 sqlite3Get4byte(const u8 *p){ 1139 #if SQLITE_BYTEORDER==4321 1140 u32 x; 1141 memcpy(&x,p,4); 1142 return x; 1143 #elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \ 1144 && defined(__GNUC__) && GCC_VERSION>=4003000 1145 u32 x; 1146 memcpy(&x,p,4); 1147 return __builtin_bswap32(x); 1148 #elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \ 1149 && defined(_MSC_VER) && _MSC_VER>=1300 1150 u32 x; 1151 memcpy(&x,p,4); 1152 return _byteswap_ulong(x); 1153 #else 1154 testcase( p[0]&0x80 ); 1155 return ((unsigned)p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3]; 1156 #endif 1157 } 1158 void sqlite3Put4byte(unsigned char *p, u32 v){ 1159 #if SQLITE_BYTEORDER==4321 1160 memcpy(p,&v,4); 1161 #elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \ 1162 && defined(__GNUC__) && GCC_VERSION>=4003000 1163 u32 x = __builtin_bswap32(v); 1164 memcpy(p,&x,4); 1165 #elif SQLITE_BYTEORDER==1234 && !defined(SQLITE_DISABLE_INTRINSIC) \ 1166 && defined(_MSC_VER) && _MSC_VER>=1300 1167 u32 x = _byteswap_ulong(v); 1168 memcpy(p,&x,4); 1169 #else 1170 p[0] = (u8)(v>>24); 1171 p[1] = (u8)(v>>16); 1172 p[2] = (u8)(v>>8); 1173 p[3] = (u8)v; 1174 #endif 1175 } 1176 1177 1178 1179 /* 1180 ** Translate a single byte of Hex into an integer. 1181 ** This routine only works if h really is a valid hexadecimal 1182 ** character: 0..9a..fA..F 1183 */ 1184 u8 sqlite3HexToInt(int h){ 1185 assert( (h>='0' && h<='9') || (h>='a' && h<='f') || (h>='A' && h<='F') ); 1186 #ifdef SQLITE_ASCII 1187 h += 9*(1&(h>>6)); 1188 #endif 1189 #ifdef SQLITE_EBCDIC 1190 h += 9*(1&~(h>>4)); 1191 #endif 1192 return (u8)(h & 0xf); 1193 } 1194 1195 #if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC) 1196 /* 1197 ** Convert a BLOB literal of the form "x'hhhhhh'" into its binary 1198 ** value. Return a pointer to its binary value. Space to hold the 1199 ** binary value has been obtained from malloc and must be freed by 1200 ** the calling routine. 1201 */ 1202 void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){ 1203 char *zBlob; 1204 int i; 1205 1206 zBlob = (char *)sqlite3DbMallocRawNN(db, n/2 + 1); 1207 n--; 1208 if( zBlob ){ 1209 for(i=0; i<n; i+=2){ 1210 zBlob[i/2] = (sqlite3HexToInt(z[i])<<4) | sqlite3HexToInt(z[i+1]); 1211 } 1212 zBlob[i/2] = 0; 1213 } 1214 return zBlob; 1215 } 1216 #endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */ 1217 1218 /* 1219 ** Log an error that is an API call on a connection pointer that should 1220 ** not have been used. The "type" of connection pointer is given as the 1221 ** argument. The zType is a word like "NULL" or "closed" or "invalid". 1222 */ 1223 static void logBadConnection(const char *zType){ 1224 sqlite3_log(SQLITE_MISUSE, 1225 "API call with %s database connection pointer", 1226 zType 1227 ); 1228 } 1229 1230 /* 1231 ** Check to make sure we have a valid db pointer. This test is not 1232 ** foolproof but it does provide some measure of protection against 1233 ** misuse of the interface such as passing in db pointers that are 1234 ** NULL or which have been previously closed. If this routine returns 1235 ** 1 it means that the db pointer is valid and 0 if it should not be 1236 ** dereferenced for any reason. The calling function should invoke 1237 ** SQLITE_MISUSE immediately. 1238 ** 1239 ** sqlite3SafetyCheckOk() requires that the db pointer be valid for 1240 ** use. sqlite3SafetyCheckSickOrOk() allows a db pointer that failed to 1241 ** open properly and is not fit for general use but which can be 1242 ** used as an argument to sqlite3_errmsg() or sqlite3_close(). 1243 */ 1244 int sqlite3SafetyCheckOk(sqlite3 *db){ 1245 u32 magic; 1246 if( db==0 ){ 1247 logBadConnection("NULL"); 1248 return 0; 1249 } 1250 magic = db->magic; 1251 if( magic!=SQLITE_MAGIC_OPEN ){ 1252 if( sqlite3SafetyCheckSickOrOk(db) ){ 1253 testcase( sqlite3GlobalConfig.xLog!=0 ); 1254 logBadConnection("unopened"); 1255 } 1256 return 0; 1257 }else{ 1258 return 1; 1259 } 1260 } 1261 int sqlite3SafetyCheckSickOrOk(sqlite3 *db){ 1262 u32 magic; 1263 magic = db->magic; 1264 if( magic!=SQLITE_MAGIC_SICK && 1265 magic!=SQLITE_MAGIC_OPEN && 1266 magic!=SQLITE_MAGIC_BUSY ){ 1267 testcase( sqlite3GlobalConfig.xLog!=0 ); 1268 logBadConnection("invalid"); 1269 return 0; 1270 }else{ 1271 return 1; 1272 } 1273 } 1274 1275 /* 1276 ** Attempt to add, substract, or multiply the 64-bit signed value iB against 1277 ** the other 64-bit signed integer at *pA and store the result in *pA. 1278 ** Return 0 on success. Or if the operation would have resulted in an 1279 ** overflow, leave *pA unchanged and return 1. 1280 */ 1281 int sqlite3AddInt64(i64 *pA, i64 iB){ 1282 i64 iA = *pA; 1283 testcase( iA==0 ); testcase( iA==1 ); 1284 testcase( iB==-1 ); testcase( iB==0 ); 1285 if( iB>=0 ){ 1286 testcase( iA>0 && LARGEST_INT64 - iA == iB ); 1287 testcase( iA>0 && LARGEST_INT64 - iA == iB - 1 ); 1288 if( iA>0 && LARGEST_INT64 - iA < iB ) return 1; 1289 }else{ 1290 testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 1 ); 1291 testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 2 ); 1292 if( iA<0 && -(iA + LARGEST_INT64) > iB + 1 ) return 1; 1293 } 1294 *pA += iB; 1295 return 0; 1296 } 1297 int sqlite3SubInt64(i64 *pA, i64 iB){ 1298 testcase( iB==SMALLEST_INT64+1 ); 1299 if( iB==SMALLEST_INT64 ){ 1300 testcase( (*pA)==(-1) ); testcase( (*pA)==0 ); 1301 if( (*pA)>=0 ) return 1; 1302 *pA -= iB; 1303 return 0; 1304 }else{ 1305 return sqlite3AddInt64(pA, -iB); 1306 } 1307 } 1308 int sqlite3MulInt64(i64 *pA, i64 iB){ 1309 i64 iA = *pA; 1310 if( iB>0 ){ 1311 if( iA>LARGEST_INT64/iB ) return 1; 1312 if( iA<SMALLEST_INT64/iB ) return 1; 1313 }else if( iB<0 ){ 1314 if( iA>0 ){ 1315 if( iB<SMALLEST_INT64/iA ) return 1; 1316 }else if( iA<0 ){ 1317 if( iB==SMALLEST_INT64 ) return 1; 1318 if( iA==SMALLEST_INT64 ) return 1; 1319 if( -iA>LARGEST_INT64/-iB ) return 1; 1320 } 1321 } 1322 *pA = iA*iB; 1323 return 0; 1324 } 1325 1326 /* 1327 ** Compute the absolute value of a 32-bit signed integer, of possible. Or 1328 ** if the integer has a value of -2147483648, return +2147483647 1329 */ 1330 int sqlite3AbsInt32(int x){ 1331 if( x>=0 ) return x; 1332 if( x==(int)0x80000000 ) return 0x7fffffff; 1333 return -x; 1334 } 1335 1336 #ifdef SQLITE_ENABLE_8_3_NAMES 1337 /* 1338 ** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database 1339 ** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and 1340 ** if filename in z[] has a suffix (a.k.a. "extension") that is longer than 1341 ** three characters, then shorten the suffix on z[] to be the last three 1342 ** characters of the original suffix. 1343 ** 1344 ** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always 1345 ** do the suffix shortening regardless of URI parameter. 1346 ** 1347 ** Examples: 1348 ** 1349 ** test.db-journal => test.nal 1350 ** test.db-wal => test.wal 1351 ** test.db-shm => test.shm 1352 ** test.db-mj7f3319fa => test.9fa 1353 */ 1354 void sqlite3FileSuffix3(const char *zBaseFilename, char *z){ 1355 #if SQLITE_ENABLE_8_3_NAMES<2 1356 if( sqlite3_uri_boolean(zBaseFilename, "8_3_names", 0) ) 1357 #endif 1358 { 1359 int i, sz; 1360 sz = sqlite3Strlen30(z); 1361 for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){} 1362 if( z[i]=='.' && ALWAYS(sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4); 1363 } 1364 } 1365 #endif 1366 1367 /* 1368 ** Find (an approximate) sum of two LogEst values. This computation is 1369 ** not a simple "+" operator because LogEst is stored as a logarithmic 1370 ** value. 1371 ** 1372 */ 1373 LogEst sqlite3LogEstAdd(LogEst a, LogEst b){ 1374 static const unsigned char x[] = { 1375 10, 10, /* 0,1 */ 1376 9, 9, /* 2,3 */ 1377 8, 8, /* 4,5 */ 1378 7, 7, 7, /* 6,7,8 */ 1379 6, 6, 6, /* 9,10,11 */ 1380 5, 5, 5, /* 12-14 */ 1381 4, 4, 4, 4, /* 15-18 */ 1382 3, 3, 3, 3, 3, 3, /* 19-24 */ 1383 2, 2, 2, 2, 2, 2, 2, /* 25-31 */ 1384 }; 1385 if( a>=b ){ 1386 if( a>b+49 ) return a; 1387 if( a>b+31 ) return a+1; 1388 return a+x[a-b]; 1389 }else{ 1390 if( b>a+49 ) return b; 1391 if( b>a+31 ) return b+1; 1392 return b+x[b-a]; 1393 } 1394 } 1395 1396 /* 1397 ** Convert an integer into a LogEst. In other words, compute an 1398 ** approximation for 10*log2(x). 1399 */ 1400 LogEst sqlite3LogEst(u64 x){ 1401 static LogEst a[] = { 0, 2, 3, 5, 6, 7, 8, 9 }; 1402 LogEst y = 40; 1403 if( x<8 ){ 1404 if( x<2 ) return 0; 1405 while( x<8 ){ y -= 10; x <<= 1; } 1406 }else{ 1407 while( x>255 ){ y += 40; x >>= 4; } /*OPTIMIZATION-IF-TRUE*/ 1408 while( x>15 ){ y += 10; x >>= 1; } 1409 } 1410 return a[x&7] + y - 10; 1411 } 1412 1413 #ifndef SQLITE_OMIT_VIRTUALTABLE 1414 /* 1415 ** Convert a double into a LogEst 1416 ** In other words, compute an approximation for 10*log2(x). 1417 */ 1418 LogEst sqlite3LogEstFromDouble(double x){ 1419 u64 a; 1420 LogEst e; 1421 assert( sizeof(x)==8 && sizeof(a)==8 ); 1422 if( x<=1 ) return 0; 1423 if( x<=2000000000 ) return sqlite3LogEst((u64)x); 1424 memcpy(&a, &x, 8); 1425 e = (a>>52) - 1022; 1426 return e*10; 1427 } 1428 #endif /* SQLITE_OMIT_VIRTUALTABLE */ 1429 1430 #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \ 1431 defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \ 1432 defined(SQLITE_EXPLAIN_ESTIMATED_ROWS) 1433 /* 1434 ** Convert a LogEst into an integer. 1435 ** 1436 ** Note that this routine is only used when one or more of various 1437 ** non-standard compile-time options is enabled. 1438 */ 1439 u64 sqlite3LogEstToInt(LogEst x){ 1440 u64 n; 1441 n = x%10; 1442 x /= 10; 1443 if( n>=5 ) n -= 2; 1444 else if( n>=1 ) n -= 1; 1445 #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \ 1446 defined(SQLITE_EXPLAIN_ESTIMATED_ROWS) 1447 if( x>60 ) return (u64)LARGEST_INT64; 1448 #else 1449 /* If only SQLITE_ENABLE_STAT3_OR_STAT4 is on, then the largest input 1450 ** possible to this routine is 310, resulting in a maximum x of 31 */ 1451 assert( x<=60 ); 1452 #endif 1453 return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x); 1454 } 1455 #endif /* defined SCANSTAT or STAT4 or ESTIMATED_ROWS */ 1456