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GeezerVison is showing github.com — sqlcipher/src/func.c at master · wolfcon/sqlcipher Expand file tree/ Copy pathfunc.cMore file actions 2032 lines (1951 loc) · 62.6 KB / Copy pathfunc.cFile metadata and controls2032 lines (1951 loc) · 62.6 KB 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 /* ** 2002 February 23 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C-language implementations for many of the SQL ** functions of SQLite. (Some function, and in particular the date and ** time functions, are implemented separately.) */ #include "sqliteInt.h" #include <stdlib.h> #include <assert.h> #include "vdbeInt.h" /* ** Return the collating function associated with a function. */ static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){ VdbeOp *pOp; assert( context->pVdbe!=0 ); pOp = &context->pVdbe->aOp[context->iOp-1]; assert( pOp->opcode==OP_CollSeq ); assert( pOp->p4type==P4_COLLSEQ ); return pOp->p4.pColl; } /* ** Indicate that the accumulator load should be skipped on this ** iteration of the aggregate loop. */ static void sqlite3SkipAccumulatorLoad(sqlite3_context *context){ assert( context->isError<=0 ); context->isError = -1; context->skipFlag = 1; } /* ** Implementation of the non-aggregate min() and max() functions */ static void minmaxFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ int i; int mask; /* 0 for min() or 0xffffffff for max() */ int iBest; CollSeq *pColl; assert( argc>1 ); mask = sqlite3_user_data(context)==0 ? 0 : -1; pColl = sqlite3GetFuncCollSeq(context); assert( pColl ); assert( mask==-1 || mask==0 ); iBest = 0; if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return; for(i=1; i<argc; i++){ if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return; if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){ testcase( mask==0 ); iBest = i; } } sqlite3_result_value(context, argv[iBest]); } /* ** Return the type of the argument. */ static void typeofFunc( sqlite3_context *context, int NotUsed, sqlite3_value **argv ){ static const char *azType[] = { "integer", "real", "text", "blob", "null" }; int i = sqlite3_value_type(argv[0]) - 1; UNUSED_PARAMETER(NotUsed); assert( i>=0 && i<ArraySize(azType) ); assert( SQLITE_INTEGER==1 ); assert( SQLITE_FLOAT==2 ); assert( SQLITE_TEXT==3 ); assert( SQLITE_BLOB==4 ); assert( SQLITE_NULL==5 ); /* EVIDENCE-OF: R-01470-60482 The sqlite3_value_type(V) interface returns ** the datatype code for the initial datatype of the sqlite3_value object ** V. The returned value is one of SQLITE_INTEGER, SQLITE_FLOAT, ** SQLITE_TEXT, SQLITE_BLOB, or SQLITE_NULL. */ sqlite3_result_text(context, azType[i], -1, SQLITE_STATIC); } /* ** Implementation of the length() function */ static void lengthFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ assert( argc==1 ); UNUSED_PARAMETER(argc); switch( sqlite3_value_type(argv[0]) ){ case SQLITE_BLOB: case SQLITE_INTEGER: case SQLITE_FLOAT: { sqlite3_result_int(context, sqlite3_value_bytes(argv[0])); break; } case SQLITE_TEXT: { const unsigned char *z = sqlite3_value_text(argv[0]); const unsigned char *z0; unsigned char c; if( z==0 ) return; z0 = z; while( (c = *z)!=0 ){ z++; if( c>=0xc0 ){ while( (*z & 0xc0)==0x80 ){ z++; z0++; } } } sqlite3_result_int(context, (int)(z-z0)); break; } default: { sqlite3_result_null(context); break; } } } /* ** Implementation of the abs() function. ** ** IMP: R-23979-26855 The abs(X) function returns the absolute value of ** the numeric argument X. */ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ assert( argc==1 ); UNUSED_PARAMETER(argc); switch( sqlite3_value_type(argv[0]) ){ case SQLITE_INTEGER: { i64 iVal = sqlite3_value_int64(argv[0]); if( iVal<0 ){ if( iVal==SMALLEST_INT64 ){ /* IMP: R-31676-45509 If X is the integer -9223372036854775808 ** then abs(X) throws an integer overflow error since there is no ** equivalent positive 64-bit two complement value. */ sqlite3_result_error(context, "integer overflow", -1); return; } iVal = -iVal; } sqlite3_result_int64(context, iVal); break; } case SQLITE_NULL: { /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */ sqlite3_result_null(context); break; } default: { /* Because sqlite3_value_double() returns 0.0 if the argument is not ** something that can be converted into a number, we have: ** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob ** that cannot be converted to a numeric value. */ double rVal = sqlite3_value_double(argv[0]); if( rVal<0 ) rVal = -rVal; sqlite3_result_double(context, rVal); break; } } } /* ** Implementation of the instr() function. ** ** instr(haystack,needle) finds the first occurrence of needle ** in haystack and returns the number of previous characters plus 1, ** or 0 if needle does not occur within haystack. ** ** If both haystack and needle are BLOBs, then the result is one more than ** the number of bytes in haystack prior to the first occurrence of needle, ** or 0 if needle never occurs in haystack. */ static void instrFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const unsigned char *zHaystack; const unsigned char *zNeedle; int nHaystack; int nNeedle; int typeHaystack, typeNeedle; int N = 1; int isText; UNUSED_PARAMETER(argc); typeHaystack = sqlite3_value_type(argv[0]); typeNeedle = sqlite3_value_type(argv[1]); if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return; nHaystack = sqlite3_value_bytes(argv[0]); nNeedle = sqlite3_value_bytes(argv[1]); if( nNeedle>0 ){ if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){ zHaystack = sqlite3_value_blob(argv[0]); zNeedle = sqlite3_value_blob(argv[1]); isText = 0; }else{ zHaystack = sqlite3_value_text(argv[0]); zNeedle = sqlite3_value_text(argv[1]); isText = 1; } if( zNeedle==0 || (nHaystack && zHaystack==0) ) return; while( nNeedle<=nHaystack && memcmp(zHaystack, zNeedle, nNeedle)!=0 ){ N++; do{ nHaystack--; zHaystack++; }while( isText && (zHaystack[0]&0xc0)==0x80 ); } if( nNeedle>nHaystack ) N = 0; } sqlite3_result_int(context, N); } /* ** Implementation of the printf() function. */ static void printfFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ PrintfArguments x; StrAccum str; const char *zFormat; int n; sqlite3 *db = sqlite3_context_db_handle(context); if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){ x.nArg = argc-1; x.nUsed = 0; x.apArg = argv+1; sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]); str.printfFlags = SQLITE_PRINTF_SQLFUNC; sqlite3_str_appendf(&str, zFormat, &x); n = str.nChar; sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n, SQLITE_DYNAMIC); } } /* ** Implementation of the substr() function. ** ** substr(x,p1,p2) returns p2 characters of x[] beginning with p1. ** p1 is 1-indexed. So substr(x,1,1) returns the first character ** of x. If x is text, then we actually count UTF-8 characters. ** If x is a blob, then we count bytes. ** ** If p1 is negative, then we begin abs(p1) from the end of x[]. ** ** If p2 is negative, return the p2 characters preceding p1. */ static void substrFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const unsigned char *z; const unsigned char *z2; int len; int p0type; i64 p1, p2; int negP2 = 0; assert( argc==3 || argc==2 ); if( sqlite3_value_type(argv[1])==SQLITE_NULL || (argc==3 && sqlite3_value_type(argv[2])==SQLITE_NULL) ){ return; } p0type = sqlite3_value_type(argv[0]); p1 = sqlite3_value_int(argv[1]); if( p0type==SQLITE_BLOB ){ len = sqlite3_value_bytes(argv[0]); z = sqlite3_value_blob(argv[0]); if( z==0 ) return; assert( len==sqlite3_value_bytes(argv[0]) ); }else{ z = sqlite3_value_text(argv[0]); if( z==0 ) return; len = 0; if( p1<0 ){ for(z2=z; *z2; len++){ SQLITE_SKIP_UTF8(z2); } } } #ifdef SQLITE_SUBSTR_COMPATIBILITY /* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as ** as substr(X,1,N) - it returns the first N characters of X. This ** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8] ** from 2009-02-02 for compatibility of applications that exploited the ** old buggy behavior. */ if( p1==0 ) p1 = 1; /* <rdar://problem/6778339> */ #endif if( argc==3 ){ p2 = sqlite3_value_int(argv[2]); if( p2<0 ){ p2 = -p2; negP2 = 1; } }else{ p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH]; } if( p1<0 ){ p1 += len; if( p1<0 ){ p2 += p1; if( p2<0 ) p2 = 0; p1 = 0; } }else if( p1>0 ){ p1--; }else if( p2>0 ){ p2--; } if( negP2 ){ p1 -= p2; if( p1<0 ){ p2 += p1; p1 = 0; } } assert( p1>=0 && p2>=0 ); if( p0type!=SQLITE_BLOB ){ while( *z && p1 ){ SQLITE_SKIP_UTF8(z); p1--; } for(z2=z; *z2 && p2; p2--){ SQLITE_SKIP_UTF8(z2); } sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT, SQLITE_UTF8); }else{ if( p1+p2>len ){ p2 = len-p1; if( p2<0 ) p2 = 0; } sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT); } } /* ** Implementation of the round() function */ #ifndef SQLITE_OMIT_FLOATING_POINT static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ int n = 0; double r; char *zBuf; assert( argc==1 || argc==2 ); if( argc==2 ){ if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return; n = sqlite3_value_int(argv[1]); if( n>30 ) n = 30; if( n<0 ) n = 0; } if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return; r = sqlite3_value_double(argv[0]); /* If Y==0 and X will fit in a 64-bit int, ** handle the rounding directly, ** otherwise use printf. */ if( n==0 && r>=0 && r<LARGEST_INT64-1 ){ r = (double)((sqlite_int64)(r+0.5)); }else if( n==0 && r<0 && (-r)<LARGEST_INT64-1 ){ r = -(double)((sqlite_int64)((-r)+0.5)); }else{ zBuf = sqlite3_mprintf("%.*f",n,r); if( zBuf==0 ){ sqlite3_result_error_nomem(context); return; } sqlite3AtoF(zBuf, &r, sqlite3Strlen30(zBuf), SQLITE_UTF8); sqlite3_free(zBuf); } sqlite3_result_double(context, r); } #endif /* ** Allocate nByte bytes of space using sqlite3Malloc(). If the ** allocation fails, call sqlite3_result_error_nomem() to notify ** the database handle that malloc() has failed and return NULL. ** If nByte is larger than the maximum string or blob length, then ** raise an SQLITE_TOOBIG exception and return NULL. */ static void *contextMalloc(sqlite3_context *context, i64 nByte){ char *z; sqlite3 *db = sqlite3_context_db_handle(context); assert( nByte>0 ); testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH] ); testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH]+1 ); if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){ sqlite3_result_error_toobig(context); z = 0; }else{ z = sqlite3Malloc(nByte); if( !z ){ sqlite3_result_error_nomem(context); } } return z; } /* ** Implementation of the upper() and lower() SQL functions. */ static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ char *z1; const char *z2; int i, n; UNUSED_PARAMETER(argc); z2 = (char*)sqlite3_value_text(argv[0]); n = sqlite3_value_bytes(argv[0]); /* Verify that the call to _bytes() does not invalidate the _text() pointer */ assert( z2==(char*)sqlite3_value_text(argv[0]) ); if( z2 ){ z1 = contextMalloc(context, ((i64)n)+1); if( z1 ){ for(i=0; i<n; i++){ z1[i] = (char)sqlite3Toupper(z2[i]); } sqlite3_result_text(context, z1, n, sqlite3_free); } } } static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ char *z1; const char *z2; int i, n; UNUSED_PARAMETER(argc); z2 = (char*)sqlite3_value_text(argv[0]); n = sqlite3_value_bytes(argv[0]); /* Verify that the call to _bytes() does not invalidate the _text() pointer */ assert( z2==(char*)sqlite3_value_text(argv[0]) ); if( z2 ){ z1 = contextMalloc(context, ((i64)n)+1); if( z1 ){ for(i=0; i<n; i++){ z1[i] = sqlite3Tolower(z2[i]); } sqlite3_result_text(context, z1, n, sqlite3_free); } } } /* ** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented ** as VDBE code so that unused argument values do not have to be computed. ** However, we still need some kind of function implementation for this ** routines in the function table. The noopFunc macro provides this. ** noopFunc will never be called so it doesn't matter what the implementation ** is. We might as well use the "version()" function as a substitute. */ #define noopFunc versionFunc /* Substitute function - never called */ /* ** Implementation of random(). Return a random integer. */ static void randomFunc( sqlite3_context *context, int NotUsed, sqlite3_value **NotUsed2 ){ sqlite_int64 r; UNUSED_PARAMETER2(NotUsed, NotUsed2); sqlite3_randomness(sizeof(r), &r); if( r<0 ){ /* We need to prevent a random number of 0x8000000000000000 ** (or -9223372036854775808) since when you do abs() of that ** number of you get the same value back again. To do this ** in a way that is testable, mask the sign bit off of negative ** values, resulting in a positive value. Then take the ** 2s complement of that positive value. The end result can ** therefore be no less than -9223372036854775807. */ r = -(r & LARGEST_INT64); } sqlite3_result_int64(context, r); } /* ** Implementation of randomblob(N). Return a random blob ** that is N bytes long. */ static void randomBlob( sqlite3_context *context, int argc, sqlite3_value **argv ){ int n; unsigned char *p; assert( argc==1 ); UNUSED_PARAMETER(argc); n = sqlite3_value_int(argv[0]); if( n<1 ){ n = 1; } p = contextMalloc(context, n); if( p ){ sqlite3_randomness(n, p); sqlite3_result_blob(context, (char*)p, n, sqlite3_free); } } /* ** Implementation of the last_insert_rowid() SQL function. The return ** value is the same as the sqlite3_last_insert_rowid() API function. */ static void last_insert_rowid( sqlite3_context *context, int NotUsed, sqlite3_value **NotUsed2 ){ sqlite3 *db = sqlite3_context_db_handle(context); UNUSED_PARAMETER2(NotUsed, NotUsed2); /* IMP: R-51513-12026 The last_insert_rowid() SQL function is a ** wrapper around the sqlite3_last_insert_rowid() C/C++ interface ** function. */ sqlite3_result_int64(context, sqlite3_last_insert_rowid(db)); } /* ** Implementation of the changes() SQL function. ** ** IMP: R-62073-11209 The changes() SQL function is a wrapper ** around the sqlite3_changes() C/C++ function and hence follows the same ** rules for counting changes. */ static void changes( sqlite3_context *context, int NotUsed, sqlite3_value **NotUsed2 ){ sqlite3 *db = sqlite3_context_db_handle(context); UNUSED_PARAMETER2(NotUsed, NotUsed2); sqlite3_result_int(context, sqlite3_changes(db)); } /* ** Implementation of the total_changes() SQL function. The return value is ** the same as the sqlite3_total_changes() API function. */ static void total_changes( sqlite3_context *context, int NotUsed, sqlite3_value **NotUsed2 ){ sqlite3 *db = sqlite3_context_db_handle(context); UNUSED_PARAMETER2(NotUsed, NotUsed2); /* IMP: R-52756-41993 This function is a wrapper around the ** sqlite3_total_changes() C/C++ interface. */ sqlite3_result_int(context, sqlite3_total_changes(db)); } /* ** A structure defining how to do GLOB-style comparisons. */ struct compareInfo { u8 matchAll; /* "*" or "%" */ u8 matchOne; /* "?" or "_" */ u8 matchSet; /* "[" or 0 */ u8 noCase; /* true to ignore case differences */ }; /* ** For LIKE and GLOB matching on EBCDIC machines, assume that every ** character is exactly one byte in size. Also, provde the Utf8Read() ** macro for fast reading of the next character in the common case where ** the next character is ASCII. */ #if defined(SQLITE_EBCDIC) # define sqlite3Utf8Read(A) (*((*A)++)) # define Utf8Read(A) (*(A++)) #else # define Utf8Read(A) (A[0]<0x80?*(A++):sqlite3Utf8Read(&A)) #endif static const struct compareInfo globInfo = { '*', '?', '[', 0 }; /* The correct SQL-92 behavior is for the LIKE operator to ignore ** case. Thus 'a' LIKE 'A' would be true. */ static const struct compareInfo likeInfoNorm = { '%', '_', 0, 1 }; /* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator ** is case sensitive causing 'a' LIKE 'A' to be false */ static const struct compareInfo likeInfoAlt = { '%', '_', 0, 0 }; /* ** Possible error returns from patternMatch() */ #define SQLITE_MATCH 0 #define SQLITE_NOMATCH 1 #define SQLITE_NOWILDCARDMATCH 2 /* ** Compare two UTF-8 strings for equality where the first string is ** a GLOB or LIKE expression. Return values: ** ** SQLITE_MATCH: Match ** SQLITE_NOMATCH: No match ** SQLITE_NOWILDCARDMATCH: No match in spite of having * or % wildcards. ** ** Globbing rules: ** ** '*' Matches any sequence of zero or more characters. ** ** '?' Matches exactly one character. ** ** [...] Matches one character from the enclosed list of ** characters. ** ** [^...] Matches one character not in the enclosed list. ** ** With the [...] and [^...] matching, a ']' character can be included ** in the list by making it the first character after '[' or '^'. A ** range of characters can be specified using '-'. Example: ** "[a-z]" matches any single lower-case letter. To match a '-', make ** it the last character in the list. ** ** Like matching rules: ** ** '%' Matches any sequence of zero or more characters ** *** '_' Matches any one character ** ** Ec Where E is the "esc" character and c is any other ** character, including '%', '_', and esc, match exactly c. ** ** The comments within this routine usually assume glob matching. ** ** This routine is usually quick, but can be N**2 in the worst case. */ static int patternCompare( const u8 *zPattern, /* The glob pattern */ const u8 *zString, /* The string to compare against the glob */ const struct compareInfo *pInfo, /* Information about how to do the compare */ u32 matchOther /* The escape char (LIKE) or '[' (GLOB) */ ){ u32 c, c2; /* Next pattern and input string chars */ u32 matchOne = pInfo->matchOne; /* "?" or "_" */ u32 matchAll = pInfo->matchAll; /* "*" or "%" */ u8 noCase = pInfo->noCase; /* True if uppercase==lowercase */ const u8 *zEscaped = 0; /* One past the last escaped input char */ while( (c = Utf8Read(zPattern))!=0 ){ if( c==matchAll ){ /* Match "*" */ /* Skip over multiple "*" characters in the pattern. If there ** are also "?" characters, skip those as well, but consume a ** single character of the input string for each "?" skipped */ while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){ if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){ return SQLITE_NOWILDCARDMATCH; } } if( c==0 ){ return SQLITE_MATCH; /* "*" at the end of the pattern matches */ }else if( c==matchOther ){ if( pInfo->matchSet==0 ){ c = sqlite3Utf8Read(&zPattern); if( c==0 ) return SQLITE_NOWILDCARDMATCH; }else{ /* "[...]" immediately follows the "*". We have to do a slow ** recursive search in this case, but it is an unusual case. */ assert( matchOther<0x80 ); /* '[' is a single-byte character */ while( *zString ){ int bMatch = patternCompare(&zPattern[-1],zString,pInfo,matchOther); if( bMatch!=SQLITE_NOMATCH ) return bMatch; SQLITE_SKIP_UTF8(zString); } return SQLITE_NOWILDCARDMATCH; } } /* At this point variable c contains the first character of the ** pattern string past the "*". Search in the input string for the ** first matching character and recursively continue the match from ** that point. ** ** For a case-insensitive search, set variable cx to be the same as ** c but in the other case and search the input string for either ** c or cx. */ if( c<=0x80 ){ char zStop[3]; int bMatch; if( noCase ){ zStop[0] = sqlite3Toupper(c); zStop[1] = sqlite3Tolower(c); zStop[2] = 0; }else{ zStop[0] = c; zStop[1] = 0; } while(1){ zString += strcspn((const char*)zString, zStop); if( zString[0]==0 ) break; zString++; bMatch = patternCompare(zPattern,zString,pInfo,matchOther); if( bMatch!=SQLITE_NOMATCH ) return bMatch; } }else{ int bMatch; while( (c2 = Utf8Read(zString))!=0 ){ if( c2!=c ) continue; bMatch = patternCompare(zPattern,zString,pInfo,matchOther); if( bMatch!=SQLITE_NOMATCH ) return bMatch; } } return SQLITE_NOWILDCARDMATCH; } if( c==matchOther ){ if( pInfo->matchSet==0 ){ c = sqlite3Utf8Read(&zPattern); if( c==0 ) return SQLITE_NOMATCH; zEscaped = zPattern; }else{ u32 prior_c = 0; int seen = 0; int invert = 0; c = sqlite3Utf8Read(&zString); if( c==0 ) return SQLITE_NOMATCH; c2 = sqlite3Utf8Read(&zPattern); if( c2=='^' ){ invert = 1; c2 = sqlite3Utf8Read(&zPattern); } if( c2==']' ){ if( c==']' ) seen = 1; c2 = sqlite3Utf8Read(&zPattern); } while( c2 && c2!=']' ){ if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){ c2 = sqlite3Utf8Read(&zPattern); if( c>=prior_c && c<=c2 ) seen = 1; prior_c = 0; }else{ if( c==c2 ){ seen = 1; } prior_c = c2; } c2 = sqlite3Utf8Read(&zPattern); } if( c2==0 || (seen ^ invert)==0 ){ return SQLITE_NOMATCH; } continue; } } c2 = Utf8Read(zString); if( c==c2 ) continue; if( noCase && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){ continue; } if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue; return SQLITE_NOMATCH; } return *zString==0 ? SQLITE_MATCH : SQLITE_NOMATCH; } /* ** The sqlite3_strglob() interface. Return 0 on a match (like strcmp()) and ** non-zero if there is no match. */ int sqlite3_strglob(const char *zGlobPattern, const char *zString){ return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '['); } /* ** The sqlite3_strlike() interface. Return 0 on a match and non-zero for ** a miss - like strcmp(). */ int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){ return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc); } /* ** Count the number of times that the LIKE operator (or GLOB which is ** just a variation of LIKE) gets called. This is used for testing ** only. */ #ifdef SQLITE_TEST int sqlite3_like_count = 0; #endif /* ** Implementation of the like() SQL function. This function implements ** the build-in LIKE operator. The first argument to the function is the ** pattern and the second argument is the string. So, the SQL statements: ** ** A LIKE B ** ** is implemented as like(B,A). ** ** This same function (with a different compareInfo structure) computes ** the GLOB operator. */ static void likeFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const unsigned char *zA, *zB; u32 escape; int nPat; sqlite3 *db = sqlite3_context_db_handle(context); struct compareInfo *pInfo = sqlite3_user_data(context); #ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS if( sqlite3_value_type(argv[0])==SQLITE_BLOB || sqlite3_value_type(argv[1])==SQLITE_BLOB ){ #ifdef SQLITE_TEST sqlite3_like_count++; #endif sqlite3_result_int(context, 0); return; } #endif zB = sqlite3_value_text(argv[0]); zA = sqlite3_value_text(argv[1]); /* Limit the length of the LIKE or GLOB pattern to avoid problems ** of deep recursion and N*N behavior in patternCompare(). */ nPat = sqlite3_value_bytes(argv[0]); testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ); testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]+1 ); if( nPat > db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){ sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1); return; } assert( zB==sqlite3_value_text(argv[0]) ); /* Encoding did not change */ if( argc==3 ){ /* The escape character string must consist of a single UTF-8 character. ** Otherwise, return an error. */ const unsigned char *zEsc = sqlite3_value_text(argv[2]); if( zEsc==0 ) return; if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){ sqlite3_result_error(context, "ESCAPE expression must be a single character", -1); return; } escape = sqlite3Utf8Read(&zEsc); }else{ escape = pInfo->matchSet; } if( zA && zB ){ #ifdef SQLITE_TEST sqlite3_like_count++; #endif sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH); } } /* ** Implementation of the NULLIF(x,y) function. The result is the first ** argument if the arguments are different. The result is NULL if the ** arguments are equal to each other. */ static void nullifFunc( sqlite3_context *context, int NotUsed, sqlite3_value **argv ){ CollSeq *pColl = sqlite3GetFuncCollSeq(context); UNUSED_PARAMETER(NotUsed); if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){ sqlite3_result_value(context, argv[0]); } } /* ** Implementation of the sqlite_version() function. The result is the version ** of the SQLite library that is running. */ static void versionFunc( sqlite3_context *context, int NotUsed, sqlite3_value **NotUsed2 ){ UNUSED_PARAMETER2(NotUsed, NotUsed2); /* IMP: R-48699-48617 This function is an SQL wrapper around the ** sqlite3_libversion() C-interface. */ sqlite3_result_text(context, sqlite3_libversion(), -1, SQLITE_STATIC); } /* ** Implementation of the sqlite_source_id() function. The result is a string ** that identifies the particular version of the source code used to build ** SQLite. */ static void sourceidFunc( sqlite3_context *context, int NotUsed, sqlite3_value **NotUsed2 ){ UNUSED_PARAMETER2(NotUsed, NotUsed2); /* IMP: R-24470-31136 This function is an SQL wrapper around the ** sqlite3_sourceid() C interface. */ sqlite3_result_text(context, sqlite3_sourceid(), -1, SQLITE_STATIC); } /* ** Implementation of the sqlite_log() function. This is a wrapper around ** sqlite3_log(). The return value is NULL. The function exists purely for ** its side-effects. */ static void errlogFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ UNUSED_PARAMETER(argc); UNUSED_PARAMETER(context); sqlite3_log(sqlite3_value_int(argv[0]), "%s", sqlite3_value_text(argv[1])); } /* ** Implementation of the sqlite_compileoption_used() function. ** The result is an integer that identifies if the compiler option ** was used to build SQLite. */ #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS static void compileoptionusedFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const char *zOptName; assert( argc==1 ); UNUSED_PARAMETER(argc); /* IMP: R-39564-36305 The sqlite_compileoption_used() SQL ** function is a wrapper around the sqlite3_compileoption_used() C/C++ ** function. */ if( (zOptName = (const char*)sqlite3_value_text(argv[0]))!=0 ){ sqlite3_result_int(context, sqlite3_compileoption_used(zOptName)); } } #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */ /* ** Implementation of the sqlite_compileoption_get() function. ** The result is a string that identifies the compiler options ** used to build SQLite. */ #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS static void compileoptiongetFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ int n; assert( argc==1 ); UNUSED_PARAMETER(argc); /* IMP: R-04922-24076 The sqlite_compileoption_get() SQL function ** is a wrapper around the sqlite3_compileoption_get() C/C++ function. */ n = sqlite3_value_int(argv[0]); sqlite3_result_text(context, sqlite3_compileoption_get(n), -1, SQLITE_STATIC); } #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */ /* Array for converting from half-bytes (nybbles) into ASCII hex ** digits. */ static const char hexdigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; /* ** Implementation of the QUOTE() function. This function takes a single ** argument. If the argument is numeric, the return value is the same as ** the argument. If the argument is NULL, the return value is the string |
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