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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 |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
c5ed5ebdf660501fde7cc8aefaaaeae2 |
User & Date: | drh 2017-07-06 16:33:14.765 |
Context
2017-07-06
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22:43 | Small adjustment to main.mk that facilitates giving non-standard compile-time options to the shell. (check-in: 7c7d53a9bb 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: 04ef6783a5 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: c5ed5ebdf6 user: drh tags: trunk) | |
13:51 | More compact implementation of the typeof() SQL function. (check-in: efb4aab0ca user: drh tags: trunk) | |
Changes
Changes to tool/mkkeywordhash.c.
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332 333 334 335 336 337 338 | */ int main(int argc, char **argv){ int i, j, k, h; int bestSize, bestCount; int count; int nChar; int totalLen = 0; | | | | 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 | */ int main(int argc, char **argv){ int i, j, k, h; int bestSize, bestCount; int count; int nChar; int totalLen = 0; int aKWHash[1000]; /* 1000 is much bigger than nKeyword */ char zKWText[2000]; /* Remove entries from the list of keywords that have mask==0 */ for(i=j=0; i<nKeyword; i++){ if( aKeywordTable[i].mask==0 ) continue; if( j<i ){ aKeywordTable[j] = aKeywordTable[i]; } |
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437 438 439 440 441 442 443 | qsort(aKeywordTable, nKeyword, sizeof(aKeywordTable[0]), keywordCompare3); /* Figure out how big to make the hash table in order to minimize the ** number of collisions */ bestSize = nKeyword; bestCount = nKeyword*nKeyword; for(i=nKeyword/2; i<=2*nKeyword; i++){ | | | | | | | | < | | | | | | | | | > | | | | > > > | | | > | | | > > | | | > | | | | > > > | | | | | 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 | qsort(aKeywordTable, nKeyword, sizeof(aKeywordTable[0]), keywordCompare3); /* Figure out how big to make the hash table in order to minimize the ** number of collisions */ bestSize = nKeyword; bestCount = nKeyword*nKeyword; for(i=nKeyword/2; i<=2*nKeyword; i++){ for(j=0; j<i; j++) aKWHash[j] = 0; for(j=0; j<nKeyword; j++){ h = aKeywordTable[j].hash % i; aKWHash[h] *= 2; aKWHash[h]++; } for(j=count=0; j<i; j++) count += aKWHash[j]; if( count<bestCount ){ bestCount = count; bestSize = i; } } /* Compute the hash */ for(i=0; i<bestSize; i++) aKWHash[i] = 0; for(i=0; i<nKeyword; i++){ h = aKeywordTable[i].hash % bestSize; aKeywordTable[i].iNext = aKWHash[h]; aKWHash[h] = i+1; } /* Begin generating code */ printf("%s", zHdr); printf("/* Hash score: %d */\n", bestCount); printf("/* zKWText[] encodes %d bytes of keyword text in %d bytes */\n", totalLen + nKeyword, nChar+1 ); for(i=j=k=0; i<nKeyword; i++){ Keyword *p = &aKeywordTable[i]; if( p->substrId ) continue; memcpy(&zKWText[k], p->zName, p->len); k += p->len; if( j+p->len>70 ){ printf("%*s */\n", 74-j, ""); j = 0; } if( j==0 ){ printf("/* "); j = 8; } printf("%s", p->zName); j += p->len; } if( j>0 ){ printf("%*s */\n", 74-j, ""); } printf("static const char zKWText[%d] = {\n", nChar); zKWText[nChar] = 0; for(i=j=0; i<k; i++){ if( j==0 ){ printf(" "); } if( zKWText[i]==0 ){ printf("0"); }else{ printf("'%c',", zKWText[i]); } j += 4; if( j>68 ){ printf("\n"); j = 0; } } if( j>0 ) printf("\n"); printf("};\n"); printf("/* aKWHash[i] is the hash value for the i-th keyword */\n"); printf("static const unsigned char aKWHash[%d] = {\n", bestSize); for(i=j=0; i<bestSize; i++){ if( j==0 ) printf(" "); printf(" %3d,", aKWHash[i]); j++; if( j>12 ){ printf("\n"); j = 0; } } printf("%s};\n", j==0 ? "" : "\n"); printf("/* aKWNext[] forms the hash collision chain. If aKWHash[i]==0\n"); printf("** then the i-th keyword has no more hash collisions. Otherwise,\n"); printf("** the next keyword with the same hash is aKWHash[i]-1. */\n"); printf("static const unsigned char aKWNext[%d] = {\n", nKeyword); for(i=j=0; i<nKeyword; i++){ if( j==0 ) printf(" "); printf(" %3d,", aKeywordTable[i].iNext); j++; if( j>12 ){ printf("\n"); j = 0; } } printf("%s};\n", j==0 ? "" : "\n"); printf("/* aKWLen[i] is the length (in bytes) of the i-th keyword */\n"); printf("static const unsigned char aKWLen[%d] = {\n", nKeyword); for(i=j=0; i<nKeyword; i++){ if( j==0 ) printf(" "); printf(" %3d,", aKeywordTable[i].len+aKeywordTable[i].prefix); j++; if( j>12 ){ printf("\n"); j = 0; } } printf("%s};\n", j==0 ? "" : "\n"); printf("/* aKWOffset[i] is the index into zKWText[] of the start of\n"); printf("** the text for the i-th keyword. */\n"); printf("static const unsigned short int aKWOffset[%d] = {\n", nKeyword); for(i=j=0; i<nKeyword; i++){ if( j==0 ) printf(" "); printf(" %3d,", aKeywordTable[i].offset); j++; if( j>12 ){ printf("\n"); j = 0; } } printf("%s};\n", j==0 ? "" : "\n"); printf("/* aKWCode[i] is the parser symbol code for the i-th keyword */\n"); printf("static const unsigned char aKWCode[%d] = {\n", nKeyword); for(i=j=0; i<nKeyword; i++){ char *zToken = aKeywordTable[i].zTokenType; if( j==0 ) printf(" "); printf("%s,%*s", zToken, (int)(14-strlen(zToken)), ""); j++; if( j>=5 ){ printf("\n"); j = 0; } } printf("%s};\n", j==0 ? "" : "\n"); printf("/* Check to see if z[0..n-1] is a keyword. If it is, write the\n"); printf("** parser symbol code for that keyword into *pType. Always\n"); printf("** return the integer n (the length of the token). */\n"); printf("static int keywordCode(const char *z, int n, int *pType){\n"); printf(" int i, j;\n"); printf(" const char *zKW;\n"); printf(" if( n>=2 ){\n"); printf(" i = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) %% %d;\n", bestSize); printf(" for(i=((int)aKWHash[i])-1; i>=0; i=((int)aKWNext[i])-1){\n"); printf(" if( aKWLen[i]!=n ) continue;\n"); printf(" j = 0;\n"); printf(" zKW = &zKWText[aKWOffset[i]];\n"); printf("#ifdef SQLITE_ASCII\n"); printf(" while( j<n && (z[j]&~0x20)==zKW[j] ){ j++; }\n"); printf("#endif\n"); printf("#ifdef SQLITE_EBCDIC\n"); printf(" while( j<n && toupper(z[j])==zKW[j] ){ j++; }\n"); printf("#endif\n"); printf(" if( j<n ) continue;\n"); for(i=0; i<nKeyword; i++){ printf(" testcase( i==%d ); /* %s */\n", i, aKeywordTable[i].zOrigName); } printf(" *pType = aKWCode[i];\n"); printf(" break;\n"); printf(" }\n"); printf(" }\n"); printf(" return n;\n"); printf("}\n"); printf("int sqlite3KeywordCode(const unsigned char *z, int n){\n"); printf(" int id = TK_ID;\n"); |
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