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Overview
| Comment: | Change the (machine-generated) keywordhash.h file to increase the scope of the tables used for keyword matching, so that the tables are accessible to functions other then keywordCode(). |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
c5ed5ebdf660501fde7cc8aefaaaeae2 |
| User & Date: | drh 2017-07-06 16:33:14 |
Context
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2017-07-06
| ||
| 22:43 | Small adjustment to main.mk that facilitates giving non-standard compile-time options to the shell. check-in: 7c7d53a9 user: drh tags: trunk | |
| 17:36 | Initial implementation of a highly experimental interface for listing all keywords and symbolic names for an SQLite database connection. check-in: 04ef6783 user: drh tags: experimental-namelist | |
| 16:33 | Change the (machine-generated) keywordhash.h file to increase the scope of the tables used for keyword matching, so that the tables are accessible to functions other then keywordCode(). check-in: c5ed5ebd user: drh tags: trunk | |
| 13:51 | More compact implementation of the typeof() SQL function. check-in: efb4aab0 user: drh tags: trunk | |
Changes
Changes to tool/mkkeywordhash.c.
332 332 */ 333 333 int main(int argc, char **argv){ 334 334 int i, j, k, h; 335 335 int bestSize, bestCount; 336 336 int count; 337 337 int nChar; 338 338 int totalLen = 0; 339 - int aHash[1000]; /* 1000 is much bigger than nKeyword */ 340 - char zText[2000]; 339 + int aKWHash[1000]; /* 1000 is much bigger than nKeyword */ 340 + char zKWText[2000]; 341 341 342 342 /* Remove entries from the list of keywords that have mask==0 */ 343 343 for(i=j=0; i<nKeyword; i++){ 344 344 if( aKeywordTable[i].mask==0 ) continue; 345 345 if( j<i ){ 346 346 aKeywordTable[j] = aKeywordTable[i]; 347 347 } ................................................................................ 437 437 qsort(aKeywordTable, nKeyword, sizeof(aKeywordTable[0]), keywordCompare3); 438 438 439 439 /* Figure out how big to make the hash table in order to minimize the 440 440 ** number of collisions */ 441 441 bestSize = nKeyword; 442 442 bestCount = nKeyword*nKeyword; 443 443 for(i=nKeyword/2; i<=2*nKeyword; i++){ 444 - for(j=0; j<i; j++) aHash[j] = 0; 444 + for(j=0; j<i; j++) aKWHash[j] = 0; 445 445 for(j=0; j<nKeyword; j++){ 446 446 h = aKeywordTable[j].hash % i; 447 - aHash[h] *= 2; 448 - aHash[h]++; 447 + aKWHash[h] *= 2; 448 + aKWHash[h]++; 449 449 } 450 - for(j=count=0; j<i; j++) count += aHash[j]; 450 + for(j=count=0; j<i; j++) count += aKWHash[j]; 451 451 if( count<bestCount ){ 452 452 bestCount = count; 453 453 bestSize = i; 454 454 } 455 455 } 456 456 457 457 /* Compute the hash */ 458 - for(i=0; i<bestSize; i++) aHash[i] = 0; 458 + for(i=0; i<bestSize; i++) aKWHash[i] = 0; 459 459 for(i=0; i<nKeyword; i++){ 460 460 h = aKeywordTable[i].hash % bestSize; 461 - aKeywordTable[i].iNext = aHash[h]; 462 - aHash[h] = i+1; 461 + aKeywordTable[i].iNext = aKWHash[h]; 462 + aKWHash[h] = i+1; 463 463 } 464 464 465 465 /* Begin generating code */ 466 466 printf("%s", zHdr); 467 467 printf("/* Hash score: %d */\n", bestCount); 468 - printf("static int keywordCode(const char *z, int n, int *pType){\n"); 469 - printf(" /* zText[] encodes %d bytes of keywords in %d bytes */\n", 468 + printf("/* zKWText[] encodes %d bytes of keyword text in %d bytes */\n", 470 469 totalLen + nKeyword, nChar+1 ); 471 470 for(i=j=k=0; i<nKeyword; i++){ 472 471 Keyword *p = &aKeywordTable[i]; 473 472 if( p->substrId ) continue; 474 - memcpy(&zText[k], p->zName, p->len); 473 + memcpy(&zKWText[k], p->zName, p->len); 475 474 k += p->len; 476 475 if( j+p->len>70 ){ 477 476 printf("%*s */\n", 74-j, ""); 478 477 j = 0; 479 478 } 480 479 if( j==0 ){ 481 - printf(" /* "); 480 + printf("/* "); 482 481 j = 8; 483 482 } 484 483 printf("%s", p->zName); 485 484 j += p->len; 486 485 } 487 486 if( j>0 ){ 488 487 printf("%*s */\n", 74-j, ""); 489 488 } 490 - printf(" static const char zText[%d] = {\n", nChar); 491 - zText[nChar] = 0; 489 + printf("static const char zKWText[%d] = {\n", nChar); 490 + zKWText[nChar] = 0; 492 491 for(i=j=0; i<k; i++){ 493 492 if( j==0 ){ 494 - printf(" "); 493 + printf(" "); 495 494 } 496 - if( zText[i]==0 ){ 495 + if( zKWText[i]==0 ){ 497 496 printf("0"); 498 497 }else{ 499 - printf("'%c',", zText[i]); 498 + printf("'%c',", zKWText[i]); 500 499 } 501 500 j += 4; 502 501 if( j>68 ){ 503 502 printf("\n"); 504 503 j = 0; 505 504 } 506 505 } 507 506 if( j>0 ) printf("\n"); 508 - printf(" };\n"); 507 + printf("};\n"); 509 508 510 - printf(" static const unsigned char aHash[%d] = {\n", bestSize); 509 + printf("/* aKWHash[i] is the hash value for the i-th keyword */\n"); 510 + printf("static const unsigned char aKWHash[%d] = {\n", bestSize); 511 511 for(i=j=0; i<bestSize; i++){ 512 - if( j==0 ) printf(" "); 513 - printf(" %3d,", aHash[i]); 512 + if( j==0 ) printf(" "); 513 + printf(" %3d,", aKWHash[i]); 514 514 j++; 515 515 if( j>12 ){ 516 516 printf("\n"); 517 517 j = 0; 518 518 } 519 519 } 520 - printf("%s };\n", j==0 ? "" : "\n"); 520 + printf("%s};\n", j==0 ? "" : "\n"); 521 521 522 - printf(" static const unsigned char aNext[%d] = {\n", nKeyword); 522 + printf("/* aKWNext[] forms the hash collision chain. If aKWHash[i]==0\n"); 523 + printf("** then the i-th keyword has no more hash collisions. Otherwise,\n"); 524 + printf("** the next keyword with the same hash is aKWHash[i]-1. */\n"); 525 + printf("static const unsigned char aKWNext[%d] = {\n", nKeyword); 523 526 for(i=j=0; i<nKeyword; i++){ 524 - if( j==0 ) printf(" "); 527 + if( j==0 ) printf(" "); 525 528 printf(" %3d,", aKeywordTable[i].iNext); 526 529 j++; 527 530 if( j>12 ){ 528 531 printf("\n"); 529 532 j = 0; 530 533 } 531 534 } 532 - printf("%s };\n", j==0 ? "" : "\n"); 535 + printf("%s};\n", j==0 ? "" : "\n"); 533 536 534 - printf(" static const unsigned char aLen[%d] = {\n", nKeyword); 537 + printf("/* aKWLen[i] is the length (in bytes) of the i-th keyword */\n"); 538 + printf("static const unsigned char aKWLen[%d] = {\n", nKeyword); 535 539 for(i=j=0; i<nKeyword; i++){ 536 - if( j==0 ) printf(" "); 540 + if( j==0 ) printf(" "); 537 541 printf(" %3d,", aKeywordTable[i].len+aKeywordTable[i].prefix); 538 542 j++; 539 543 if( j>12 ){ 540 544 printf("\n"); 541 545 j = 0; 542 546 } 543 547 } 544 - printf("%s };\n", j==0 ? "" : "\n"); 548 + printf("%s};\n", j==0 ? "" : "\n"); 545 549 546 - printf(" static const unsigned short int aOffset[%d] = {\n", nKeyword); 550 + printf("/* aKWOffset[i] is the index into zKWText[] of the start of\n"); 551 + printf("** the text for the i-th keyword. */\n"); 552 + printf("static const unsigned short int aKWOffset[%d] = {\n", nKeyword); 547 553 for(i=j=0; i<nKeyword; i++){ 548 - if( j==0 ) printf(" "); 554 + if( j==0 ) printf(" "); 549 555 printf(" %3d,", aKeywordTable[i].offset); 550 556 j++; 551 557 if( j>12 ){ 552 558 printf("\n"); 553 559 j = 0; 554 560 } 555 561 } 556 - printf("%s };\n", j==0 ? "" : "\n"); 562 + printf("%s};\n", j==0 ? "" : "\n"); 557 563 558 - printf(" static const unsigned char aCode[%d] = {\n", nKeyword); 564 + printf("/* aKWCode[i] is the parser symbol code for the i-th keyword */\n"); 565 + printf("static const unsigned char aKWCode[%d] = {\n", nKeyword); 559 566 for(i=j=0; i<nKeyword; i++){ 560 567 char *zToken = aKeywordTable[i].zTokenType; 561 - if( j==0 ) printf(" "); 568 + if( j==0 ) printf(" "); 562 569 printf("%s,%*s", zToken, (int)(14-strlen(zToken)), ""); 563 570 j++; 564 571 if( j>=5 ){ 565 572 printf("\n"); 566 573 j = 0; 567 574 } 568 575 } 569 - printf("%s };\n", j==0 ? "" : "\n"); 570 - 576 + printf("%s};\n", j==0 ? "" : "\n"); 577 + printf("/* Check to see if z[0..n-1] is a keyword. If it is, write the\n"); 578 + printf("** parser symbol code for that keyword into *pType. Always\n"); 579 + printf("** return the integer n (the length of the token). */\n"); 580 + printf("static int keywordCode(const char *z, int n, int *pType){\n"); 571 581 printf(" int i, j;\n"); 572 582 printf(" const char *zKW;\n"); 573 583 printf(" if( n>=2 ){\n"); 574 584 printf(" i = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) %% %d;\n", 575 585 bestSize); 576 - printf(" for(i=((int)aHash[i])-1; i>=0; i=((int)aNext[i])-1){\n"); 577 - printf(" if( aLen[i]!=n ) continue;\n"); 586 + printf(" for(i=((int)aKWHash[i])-1; i>=0; i=((int)aKWNext[i])-1){\n"); 587 + printf(" if( aKWLen[i]!=n ) continue;\n"); 578 588 printf(" j = 0;\n"); 579 - printf(" zKW = &zText[aOffset[i]];\n"); 589 + printf(" zKW = &zKWText[aKWOffset[i]];\n"); 580 590 printf("#ifdef SQLITE_ASCII\n"); 581 591 printf(" while( j<n && (z[j]&~0x20)==zKW[j] ){ j++; }\n"); 582 592 printf("#endif\n"); 583 593 printf("#ifdef SQLITE_EBCDIC\n"); 584 594 printf(" while( j<n && toupper(z[j])==zKW[j] ){ j++; }\n"); 585 595 printf("#endif\n"); 586 596 printf(" if( j<n ) continue;\n"); 587 597 for(i=0; i<nKeyword; i++){ 588 598 printf(" testcase( i==%d ); /* %s */\n", 589 599 i, aKeywordTable[i].zOrigName); 590 600 } 591 - printf(" *pType = aCode[i];\n"); 601 + printf(" *pType = aKWCode[i];\n"); 592 602 printf(" break;\n"); 593 603 printf(" }\n"); 594 604 printf(" }\n"); 595 605 printf(" return n;\n"); 596 606 printf("}\n"); 597 607 printf("int sqlite3KeywordCode(const unsigned char *z, int n){\n"); 598 608 printf(" int id = TK_ID;\n");