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[chromium-blink-merge.git] / third_party / sqlite / sqlite-src-3080704 / ext / misc / spellfix.c
blob2a26e08391dee26edfb09435943cae897a80f094
1 /*
2 ** 2012 April 10
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 **
13 ** This module implements the spellfix1 VIRTUAL TABLE that can be used
14 ** to search a large vocabulary for close matches. See separate
15 ** documentation (http://www.sqlite.org/spellfix1.html) for details.
16 */
17 #include "sqlite3ext.h"
18 SQLITE_EXTENSION_INIT1
19
20 #ifndef SQLITE_AMALGAMATION
21 # include <string.h>
22 # include <stdio.h>
23 # include <stdlib.h>
24 # include <assert.h>
25 # define ALWAYS(X) 1
26 # define NEVER(X) 0
27 typedef unsigned char u8;
28 typedef unsigned short u16;
29 #endif
30 #include <ctype.h>
31
32 #ifndef SQLITE_OMIT_VIRTUALTABLE
33
34 /*
35 ** Character classes for ASCII characters:
36 **
37 ** 0 '' Silent letters: H W
38 ** 1 'A' Any vowel: A E I O U (Y)
39 ** 2 'B' A bilabeal stop or fricative: B F P V W
40 ** 3 'C' Other fricatives or back stops: C G J K Q S X Z
41 ** 4 'D' Alveolar stops: D T
42 ** 5 'H' Letter H at the beginning of a word
43 ** 6 'L' Glide: L
44 ** 7 'R' Semivowel: R
45 ** 8 'M' Nasals: M N
46 ** 9 'Y' Letter Y at the beginning of a word.
47 ** 10 '9' Digits: 0 1 2 3 4 5 6 7 8 9
48 ** 11 ' ' White space
49 ** 12 '?' Other.
50 */
51 #define CCLASS_SILENT 0
52 #define CCLASS_VOWEL 1
53 #define CCLASS_B 2
54 #define CCLASS_C 3
55 #define CCLASS_D 4
56 #define CCLASS_H 5
57 #define CCLASS_L 6
58 #define CCLASS_R 7
59 #define CCLASS_M 8
60 #define CCLASS_Y 9
61 #define CCLASS_DIGIT 10
62 #define CCLASS_SPACE 11
63 #define CCLASS_OTHER 12
64
65 /*
66 ** The following table gives the character class for non-initial ASCII
67 ** characters.
68 */
69 static const unsigned char midClass[] = {
70 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
71 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
72 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
73 /* */ CCLASS_SPACE, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
74 /* */ CCLASS_SPACE, /* */ CCLASS_SPACE, /* */ CCLASS_OTHER,
75 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
76 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
77 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
78 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
79 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
80 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE,
81 /* ! */ CCLASS_OTHER, /* " */ CCLASS_OTHER, /* # */ CCLASS_OTHER,
82 /* $ */ CCLASS_OTHER, /* % */ CCLASS_OTHER, /* & */ CCLASS_OTHER,
83 /* ' */ CCLASS_SILENT, /* ( */ CCLASS_OTHER, /* ) */ CCLASS_OTHER,
84 /* * */ CCLASS_OTHER, /* + */ CCLASS_OTHER, /* , */ CCLASS_OTHER,
85 /* - */ CCLASS_OTHER, /* . */ CCLASS_OTHER, /* / */ CCLASS_OTHER,
86 /* 0 */ CCLASS_DIGIT, /* 1 */ CCLASS_DIGIT, /* 2 */ CCLASS_DIGIT,
87 /* 3 */ CCLASS_DIGIT, /* 4 */ CCLASS_DIGIT, /* 5 */ CCLASS_DIGIT,
88 /* 6 */ CCLASS_DIGIT, /* 7 */ CCLASS_DIGIT, /* 8 */ CCLASS_DIGIT,
89 /* 9 */ CCLASS_DIGIT, /* : */ CCLASS_OTHER, /* ; */ CCLASS_OTHER,
90 /* < */ CCLASS_OTHER, /* = */ CCLASS_OTHER, /* > */ CCLASS_OTHER,
91 /* ? */ CCLASS_OTHER, /* @ */ CCLASS_OTHER, /* A */ CCLASS_VOWEL,
92 /* B */ CCLASS_B, /* C */ CCLASS_C, /* D */ CCLASS_D,
93 /* E */ CCLASS_VOWEL, /* F */ CCLASS_B, /* G */ CCLASS_C,
94 /* H */ CCLASS_SILENT, /* I */ CCLASS_VOWEL, /* J */ CCLASS_C,
95 /* K */ CCLASS_C, /* L */ CCLASS_L, /* M */ CCLASS_M,
96 /* N */ CCLASS_M, /* O */ CCLASS_VOWEL, /* P */ CCLASS_B,
97 /* Q */ CCLASS_C, /* R */ CCLASS_R, /* S */ CCLASS_C,
98 /* T */ CCLASS_D, /* U */ CCLASS_VOWEL, /* V */ CCLASS_B,
99 /* W */ CCLASS_B, /* X */ CCLASS_C, /* Y */ CCLASS_VOWEL,
100 /* Z */ CCLASS_C, /* [ */ CCLASS_OTHER, /* \ */ CCLASS_OTHER,
101 /* ] */ CCLASS_OTHER, /* ^ */ CCLASS_OTHER, /* _ */ CCLASS_OTHER,
102 /* ` */ CCLASS_OTHER, /* a */ CCLASS_VOWEL, /* b */ CCLASS_B,
103 /* c */ CCLASS_C, /* d */ CCLASS_D, /* e */ CCLASS_VOWEL,
104 /* f */ CCLASS_B, /* g */ CCLASS_C, /* h */ CCLASS_SILENT,
105 /* i */ CCLASS_VOWEL, /* j */ CCLASS_C, /* k */ CCLASS_C,
106 /* l */ CCLASS_L, /* m */ CCLASS_M, /* n */ CCLASS_M,
107 /* o */ CCLASS_VOWEL, /* p */ CCLASS_B, /* q */ CCLASS_C,
108 /* r */ CCLASS_R, /* s */ CCLASS_C, /* t */ CCLASS_D,
109 /* u */ CCLASS_VOWEL, /* v */ CCLASS_B, /* w */ CCLASS_B,
110 /* x */ CCLASS_C, /* y */ CCLASS_VOWEL, /* z */ CCLASS_C,
111 /* { */ CCLASS_OTHER, /* | */ CCLASS_OTHER, /* } */ CCLASS_OTHER,
112 /* ~ */ CCLASS_OTHER, /* */ CCLASS_OTHER,
113 };
114 /*
115 ** This tables gives the character class for ASCII characters that form the
116 ** initial character of a word. The only difference from midClass is with
117 ** the letters H, W, and Y.
118 */
119 static const unsigned char initClass[] = {
120 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
121 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
122 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
123 /* */ CCLASS_SPACE, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
124 /* */ CCLASS_SPACE, /* */ CCLASS_SPACE, /* */ CCLASS_OTHER,
125 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
126 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
127 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
128 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
129 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER,
130 /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE,
131 /* ! */ CCLASS_OTHER, /* " */ CCLASS_OTHER, /* # */ CCLASS_OTHER,
132 /* $ */ CCLASS_OTHER, /* % */ CCLASS_OTHER, /* & */ CCLASS_OTHER,
133 /* ' */ CCLASS_OTHER, /* ( */ CCLASS_OTHER, /* ) */ CCLASS_OTHER,
134 /* * */ CCLASS_OTHER, /* + */ CCLASS_OTHER, /* , */ CCLASS_OTHER,
135 /* - */ CCLASS_OTHER, /* . */ CCLASS_OTHER, /* / */ CCLASS_OTHER,
136 /* 0 */ CCLASS_DIGIT, /* 1 */ CCLASS_DIGIT, /* 2 */ CCLASS_DIGIT,
137 /* 3 */ CCLASS_DIGIT, /* 4 */ CCLASS_DIGIT, /* 5 */ CCLASS_DIGIT,
138 /* 6 */ CCLASS_DIGIT, /* 7 */ CCLASS_DIGIT, /* 8 */ CCLASS_DIGIT,
139 /* 9 */ CCLASS_DIGIT, /* : */ CCLASS_OTHER, /* ; */ CCLASS_OTHER,
140 /* < */ CCLASS_OTHER, /* = */ CCLASS_OTHER, /* > */ CCLASS_OTHER,
141 /* ? */ CCLASS_OTHER, /* @ */ CCLASS_OTHER, /* A */ CCLASS_VOWEL,
142 /* B */ CCLASS_B, /* C */ CCLASS_C, /* D */ CCLASS_D,
143 /* E */ CCLASS_VOWEL, /* F */ CCLASS_B, /* G */ CCLASS_C,
144 /* H */ CCLASS_SILENT, /* I */ CCLASS_VOWEL, /* J */ CCLASS_C,
145 /* K */ CCLASS_C, /* L */ CCLASS_L, /* M */ CCLASS_M,
146 /* N */ CCLASS_M, /* O */ CCLASS_VOWEL, /* P */ CCLASS_B,
147 /* Q */ CCLASS_C, /* R */ CCLASS_R, /* S */ CCLASS_C,
148 /* T */ CCLASS_D, /* U */ CCLASS_VOWEL, /* V */ CCLASS_B,
149 /* W */ CCLASS_B, /* X */ CCLASS_C, /* Y */ CCLASS_Y,
150 /* Z */ CCLASS_C, /* [ */ CCLASS_OTHER, /* \ */ CCLASS_OTHER,
151 /* ] */ CCLASS_OTHER, /* ^ */ CCLASS_OTHER, /* _ */ CCLASS_OTHER,
152 /* ` */ CCLASS_OTHER, /* a */ CCLASS_VOWEL, /* b */ CCLASS_B,
153 /* c */ CCLASS_C, /* d */ CCLASS_D, /* e */ CCLASS_VOWEL,
154 /* f */ CCLASS_B, /* g */ CCLASS_C, /* h */ CCLASS_SILENT,
155 /* i */ CCLASS_VOWEL, /* j */ CCLASS_C, /* k */ CCLASS_C,
156 /* l */ CCLASS_L, /* m */ CCLASS_M, /* n */ CCLASS_M,
157 /* o */ CCLASS_VOWEL, /* p */ CCLASS_B, /* q */ CCLASS_C,
158 /* r */ CCLASS_R, /* s */ CCLASS_C, /* t */ CCLASS_D,
159 /* u */ CCLASS_VOWEL, /* v */ CCLASS_B, /* w */ CCLASS_B,
160 /* x */ CCLASS_C, /* y */ CCLASS_Y, /* z */ CCLASS_C,
161 /* { */ CCLASS_OTHER, /* | */ CCLASS_OTHER, /* } */ CCLASS_OTHER,
162 /* ~ */ CCLASS_OTHER, /* */ CCLASS_OTHER,
163 };
164
165 /*
166 ** Mapping from the character class number (0-13) to a symbol for each
167 ** character class. Note that initClass[] can be used to map the class
168 ** symbol back into the class number.
169 */
170 static const unsigned char className[] = ".ABCDHLRMY9 ?";
171
172 /*
173 ** Generate a "phonetic hash" from a string of ASCII characters
174 ** in zIn[0..nIn-1].
175 **
176 ** * Map characters by character class as defined above.
177 ** * Omit double-letters
178 ** * Omit vowels beside R and L
179 ** * Omit T when followed by CH
180 ** * Omit W when followed by R
181 ** * Omit D when followed by J or G
182 ** * Omit K in KN or G in GN at the beginning of a word
183 **
184 ** Space to hold the result is obtained from sqlite3_malloc()
185 **
186 ** Return NULL if memory allocation fails.
187 */
188 static unsigned char *phoneticHash(const unsigned char *zIn, int nIn){
189 unsigned char *zOut = sqlite3_malloc( nIn + 1 );
190 int i;
191 int nOut = 0;
192 char cPrev = 0x77;
193 char cPrevX = 0x77;
194 const unsigned char *aClass = initClass;
195
196 if( zOut==0 ) return 0;
197 if( nIn>2 ){
198 switch( zIn[0] ){
199 case 'g':
200 case 'k': {
201 if( zIn[1]=='n' ){ zIn++; nIn--; }
202 break;
203 }
204 }
205 }
206 for(i=0; i<nIn; i++){
207 unsigned char c = zIn[i];
208 if( i+1<nIn ){
209 if( c=='w' && zIn[i+1]=='r' ) continue;
210 if( c=='d' && (zIn[i+1]=='j' || zIn[i+1]=='g') ) continue;
211 if( i+2<nIn ){
212 if( c=='t' && zIn[i+1]=='c' && zIn[i+2]=='h' ) continue;
213 }
214 }
215 c = aClass[c&0x7f];
216 if( c==CCLASS_SPACE ) continue;
217 if( c==CCLASS_OTHER && cPrev!=CCLASS_DIGIT ) continue;
218 aClass = midClass;
219 if( c==CCLASS_VOWEL && (cPrevX==CCLASS_R || cPrevX==CCLASS_L) ){
220 continue; /* No vowels beside L or R */
221 }
222 if( (c==CCLASS_R || c==CCLASS_L) && cPrevX==CCLASS_VOWEL ){
223 nOut--; /* No vowels beside L or R */
224 }
225 cPrev = c;
226 if( c==CCLASS_SILENT ) continue;
227 cPrevX = c;
228 c = className[c];
229 assert( nOut>=0 );
230 if( nOut==0 || c!=zOut[nOut-1] ) zOut[nOut++] = c;
231 }
232 zOut[nOut] = 0;
233 return zOut;
234 }
235
236 /*
237 ** This is an SQL function wrapper around phoneticHash(). See
238 ** the description of phoneticHash() for additional information.
239 */
240 static void phoneticHashSqlFunc(
241 sqlite3_context *context,
242 int argc,
243 sqlite3_value **argv
244 ){
245 const unsigned char *zIn;
246 unsigned char *zOut;
247
248 zIn = sqlite3_value_text(argv[0]);
249 if( zIn==0 ) return;
250 zOut = phoneticHash(zIn, sqlite3_value_bytes(argv[0]));
251 if( zOut==0 ){
252 sqlite3_result_error_nomem(context);
253 }else{
254 sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free);
255 }
256 }
257
258 /*
259 ** Return the character class number for a character given its
260 ** context.
261 */
262 static char characterClass(char cPrev, char c){
263 return cPrev==0 ? initClass[c&0x7f] : midClass[c&0x7f];
264 }
265
266 /*
267 ** Return the cost of inserting or deleting character c immediately
268 ** following character cPrev. If cPrev==0, that means c is the first
269 ** character of the word.
270 */
271 static int insertOrDeleteCost(char cPrev, char c, char cNext){
272 char classC = characterClass(cPrev, c);
273 char classCprev;
274
275 if( classC==CCLASS_SILENT ){
276 /* Insert or delete "silent" characters such as H or W */
277 return 1;
278 }
279 if( cPrev==c ){
280 /* Repeated characters, or miss a repeat */
281 return 10;
282 }
283 if( classC==CCLASS_VOWEL && (cPrev=='r' || cNext=='r') ){
284 return 20; /* Insert a vowel before or after 'r' */
285 }
286 classCprev = characterClass(cPrev, cPrev);
287 if( classC==classCprev ){
288 if( classC==CCLASS_VOWEL ){
289 /* Remove or add a new vowel to a vowel cluster */
290 return 15;
291 }else{
292 /* Remove or add a consonant not in the same class */
293 return 50;
294 }
295 }
296
297 /* any other character insertion or deletion */
298 return 100;
299 }
300
301 /*
302 ** Divide the insertion cost by this factor when appending to the
303 ** end of the word.
304 */
305 #define FINAL_INS_COST_DIV 4
306
307 /*
308 ** Return the cost of substituting cTo in place of cFrom assuming
309 ** the previous character is cPrev. If cPrev==0 then cTo is the first
310 ** character of the word.
311 */
312 static int substituteCost(char cPrev, char cFrom, char cTo){
313 char classFrom, classTo;
314 if( cFrom==cTo ){
315 /* Exact match */
316 return 0;
317 }
318 if( cFrom==(cTo^0x20) && ((cTo>='A' && cTo<='Z') || (cTo>='a' && cTo<='z')) ){
319 /* differ only in case */
320 return 0;
321 }
322 classFrom = characterClass(cPrev, cFrom);
323 classTo = characterClass(cPrev, cTo);
324 if( classFrom==classTo ){
325 /* Same character class */
326 return 40;
327 }
328 if( classFrom>=CCLASS_B && classFrom<=CCLASS_Y
329 && classTo>=CCLASS_B && classTo<=CCLASS_Y ){
330 /* Convert from one consonant to another, but in a different class */
331 return 75;
332 }
333 /* Any other subsitution */
334 return 100;
335 }
336
337 /*
338 ** Given two strings zA and zB which are pure ASCII, return the cost
339 ** of transforming zA into zB. If zA ends with '*' assume that it is
340 ** a prefix of zB and give only minimal penalty for extra characters
341 ** on the end of zB.
342 **
343 ** Smaller numbers mean a closer match.
344 **
345 ** Negative values indicate an error:
346 ** -1 One of the inputs is NULL
347 ** -2 Non-ASCII characters on input
348 ** -3 Unable to allocate memory
349 **
350 ** If pnMatch is not NULL, then *pnMatch is set to the number of bytes
351 ** of zB that matched the pattern in zA. If zA does not end with a '*',
352 ** then this value is always the number of bytes in zB (i.e. strlen(zB)).
353 ** If zA does end in a '*', then it is the number of bytes in the prefix
354 ** of zB that was deemed to match zA.
355 */
356 static int editdist1(const char *zA, const char *zB, int *pnMatch){
357 int nA, nB; /* Number of characters in zA[] and zB[] */
358 int xA, xB; /* Loop counters for zA[] and zB[] */
359 char cA, cB; /* Current character of zA and zB */
360 char cAprev, cBprev; /* Previous character of zA and zB */
361 char cAnext, cBnext; /* Next character in zA and zB */
362 int d; /* North-west cost value */
363 int dc = 0; /* North-west character value */
364 int res; /* Final result */
365 int *m; /* The cost matrix */
366 char *cx; /* Corresponding character values */
367 int *toFree = 0; /* Malloced space */
368 int mStack[60+15]; /* Stack space to use if not too much is needed */
369 int nMatch = 0;
370
371 /* Early out if either input is NULL */
372 if( zA==0 || zB==0 ) return -1;
373
374 /* Skip any common prefix */
375 while( zA[0] && zA[0]==zB[0] ){ dc = zA[0]; zA++; zB++; nMatch++; }
376 if( pnMatch ) *pnMatch = nMatch;
377 if( zA[0]==0 && zB[0]==0 ) return 0;
378
379 #if 0
380 printf("A=\"%s\" B=\"%s\" dc=%c\n", zA, zB, dc?dc:' ');
381 #endif
382
383 /* Verify input strings and measure their lengths */
384 for(nA=0; zA[nA]; nA++){
385 if( zA[nA]&0x80 ) return -2;
386 }
387 for(nB=0; zB[nB]; nB++){
388 if( zB[nB]&0x80 ) return -2;
389 }
390
391 /* Special processing if either string is empty */
392 if( nA==0 ){
393 cBprev = dc;
394 for(xB=res=0; (cB = zB[xB])!=0; xB++){
395 res += insertOrDeleteCost(cBprev, cB, zB[xB+1])/FINAL_INS_COST_DIV;
396 cBprev = cB;
397 }
398 return res;
399 }
400 if( nB==0 ){
401 cAprev = dc;
402 for(xA=res=0; (cA = zA[xA])!=0; xA++){
403 res += insertOrDeleteCost(cAprev, cA, zA[xA+1]);
404 cAprev = cA;
405 }
406 return res;
407 }
408
409 /* A is a prefix of B */
410 if( zA[0]=='*' && zA[1]==0 ) return 0;
411
412 /* Allocate and initialize the Wagner matrix */
413 if( nB<(sizeof(mStack)*4)/(sizeof(mStack[0])*5) ){
414 m = mStack;
415 }else{
416 m = toFree = sqlite3_malloc( (nB+1)*5*sizeof(m[0])/4 );
417 if( m==0 ) return -3;
418 }
419 cx = (char*)&m[nB+1];
420
421 /* Compute the Wagner edit distance */
422 m[0] = 0;
423 cx[0] = dc;
424 cBprev = dc;
425 for(xB=1; xB<=nB; xB++){
426 cBnext = zB[xB];
427 cB = zB[xB-1];
428 cx[xB] = cB;
429 m[xB] = m[xB-1] + insertOrDeleteCost(cBprev, cB, cBnext);
430 cBprev = cB;
431 }
432 cAprev = dc;
433 for(xA=1; xA<=nA; xA++){
434 int lastA = (xA==nA);
435 cA = zA[xA-1];
436 cAnext = zA[xA];
437 if( cA=='*' && lastA ) break;
438 d = m[0];
439 dc = cx[0];
440 m[0] = d + insertOrDeleteCost(cAprev, cA, cAnext);
441 cBprev = 0;
442 for(xB=1; xB<=nB; xB++){
443 int totalCost, insCost, delCost, subCost, ncx;
444 cB = zB[xB-1];
445 cBnext = zB[xB];
446
447 /* Cost to insert cB */
448 insCost = insertOrDeleteCost(cx[xB-1], cB, cBnext);
449 if( lastA ) insCost /= FINAL_INS_COST_DIV;
450
451 /* Cost to delete cA */
452 delCost = insertOrDeleteCost(cx[xB], cA, cBnext);
453
454 /* Cost to substitute cA->cB */
455 subCost = substituteCost(cx[xB-1], cA, cB);
456
457 /* Best cost */
458 totalCost = insCost + m[xB-1];
459 ncx = cB;
460 if( (delCost + m[xB])<totalCost ){
461 totalCost = delCost + m[xB];
462 ncx = cA;
463 }
464 if( (subCost + d)<totalCost ){
465 totalCost = subCost + d;
466 }
467
468 #if 0
469 printf("%d,%d d=%4d u=%4d r=%4d dc=%c cA=%c cB=%c"
470 " ins=%4d del=%4d sub=%4d t=%4d ncx=%c\n",
471 xA, xB, d, m[xB], m[xB-1], dc?dc:' ', cA, cB,
472 insCost, delCost, subCost, totalCost, ncx?ncx:' ');
473 #endif
474
475 /* Update the matrix */
476 d = m[xB];
477 dc = cx[xB];
478 m[xB] = totalCost;
479 cx[xB] = ncx;
480 cBprev = cB;
481 }
482 cAprev = cA;
483 }
484
485 /* Free the wagner matrix and return the result */
486 if( cA=='*' ){
487 res = m[1];
488 for(xB=1; xB<=nB; xB++){
489 if( m[xB]<res ){
490 res = m[xB];
491 if( pnMatch ) *pnMatch = xB+nMatch;
492 }
493 }
494 }else{
495 res = m[nB];
496 /* In the current implementation, pnMatch is always NULL if zA does
497 ** not end in "*" */
498 assert( pnMatch==0 );
499 }
500 sqlite3_free(toFree);
501 return res;
502 }
503
504 /*
505 ** Function: editdist(A,B)
506 **
507 ** Return the cost of transforming string A into string B. Both strings
508 ** must be pure ASCII text. If A ends with '*' then it is assumed to be
509 ** a prefix of B and extra characters on the end of B have minimal additional
510 ** cost.
511 */
512 static void editdistSqlFunc(
513 sqlite3_context *context,
514 int argc,
515 sqlite3_value **argv
516 ){
517 int res = editdist1(
518 (const char*)sqlite3_value_text(argv[0]),
519 (const char*)sqlite3_value_text(argv[1]),
520 0);
521 if( res<0 ){
522 if( res==(-3) ){
523 sqlite3_result_error_nomem(context);
524 }else if( res==(-2) ){
525 sqlite3_result_error(context, "non-ASCII input to editdist()", -1);
526 }else{
527 sqlite3_result_error(context, "NULL input to editdist()", -1);
528 }
529 }else{
530 sqlite3_result_int(context, res);
531 }
532 }
533
534 /* End of the fixed-cost edit distance implementation
535 ******************************************************************************
536 *****************************************************************************
537 ** Begin: Configurable cost unicode edit distance routines
538 */
539 /* Forward declaration of structures */
540 typedef struct EditDist3Cost EditDist3Cost;
541 typedef struct EditDist3Config EditDist3Config;
542 typedef struct EditDist3Point EditDist3Point;
543 typedef struct EditDist3From EditDist3From;
544 typedef struct EditDist3FromString EditDist3FromString;
545 typedef struct EditDist3To EditDist3To;
546 typedef struct EditDist3ToString EditDist3ToString;
547 typedef struct EditDist3Lang EditDist3Lang;
548
549
550 /*
551 ** An entry in the edit cost table
552 */
553 struct EditDist3Cost {
554 EditDist3Cost *pNext; /* Next cost element */
555 u8 nFrom; /* Number of bytes in aFrom */
556 u8 nTo; /* Number of bytes in aTo */
557 u16 iCost; /* Cost of this transformation */
558 char a[4] ; /* FROM string followed by TO string */
559 /* Additional TO and FROM string bytes appended as necessary */
560 };
561
562 /*
563 ** Edit costs for a particular language ID
564 */
565 struct EditDist3Lang {
566 int iLang; /* Language ID */
567 int iInsCost; /* Default insertion cost */
568 int iDelCost; /* Default deletion cost */
569 int iSubCost; /* Default substitution cost */
570 EditDist3Cost *pCost; /* Costs */
571 };
572
573
574 /*
575 ** The default EditDist3Lang object, with default costs.
576 */
577 static const EditDist3Lang editDist3Lang = { 0, 100, 100, 150, 0 };
578
579 /*
580 ** Complete configuration
581 */
582 struct EditDist3Config {
583 int nLang; /* Number of language IDs. Size of a[] */
584 EditDist3Lang *a; /* One for each distinct language ID */
585 };
586
587 /*
588 ** Extra information about each character in the FROM string.
589 */
590 struct EditDist3From {
591 int nSubst; /* Number of substitution cost entries */
592 int nDel; /* Number of deletion cost entries */
593 int nByte; /* Number of bytes in this character */
594 EditDist3Cost **apSubst; /* Array of substitution costs for this element */
595 EditDist3Cost **apDel; /* Array of deletion cost entries */
596 };
597
598 /*
599 ** A precompiled FROM string.
600 *
601 ** In the common case we expect the FROM string to be reused multiple times.
602 ** In other words, the common case will be to measure the edit distance
603 ** from a single origin string to multiple target strings.
604 */
605 struct EditDist3FromString {
606 char *z; /* The complete text of the FROM string */
607 int n; /* Number of characters in the FROM string */
608 int isPrefix; /* True if ends with '*' character */
609 EditDist3From *a; /* Extra info about each char of the FROM string */
610 };
611
612 /*
613 ** Extra information about each character in the TO string.
614 */
615 struct EditDist3To {
616 int nIns; /* Number of insertion cost entries */
617 int nByte; /* Number of bytes in this character */
618 EditDist3Cost **apIns; /* Array of deletion cost entries */
619 };
620
621 /*
622 ** A precompiled FROM string
623 */
624 struct EditDist3ToString {
625 char *z; /* The complete text of the TO string */
626 int n; /* Number of characters in the TO string */
627 EditDist3To *a; /* Extra info about each char of the TO string */
628 };
629
630 /*
631 ** Clear or delete an instance of the object that records all edit-distance
632 ** weights.
633 */
634 static void editDist3ConfigClear(EditDist3Config *p){
635 int i;
636 if( p==0 ) return;
637 for(i=0; i<p->nLang; i++){
638 EditDist3Cost *pCost, *pNext;
639 pCost = p->a[i].pCost;
640 while( pCost ){
641 pNext = pCost->pNext;
642 sqlite3_free(pCost);
643 pCost = pNext;
644 }
645 }
646 sqlite3_free(p->a);
647 memset(p, 0, sizeof(*p));
648 }
649 static void editDist3ConfigDelete(void *pIn){
650 EditDist3Config *p = (EditDist3Config*)pIn;
651 editDist3ConfigClear(p);
652 sqlite3_free(p);
653 }
654
655 /*
656 ** Load all edit-distance weights from a table.
657 */
658 static int editDist3ConfigLoad(
659 EditDist3Config *p, /* The edit distance configuration to load */
660 sqlite3 *db, /* Load from this database */
661 const char *zTable /* Name of the table from which to load */
662 ){
663 sqlite3_stmt *pStmt;
664 int rc, rc2;
665 char *zSql;
666 int iLangPrev = -9999;
667 EditDist3Lang *pLang = 0;
668
669 zSql = sqlite3_mprintf("SELECT iLang, cFrom, cTo, iCost"
670 " FROM \"%w\" WHERE iLang>=0 ORDER BY iLang", zTable);
671 if( zSql==0 ) return SQLITE_NOMEM;
672 rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
673 sqlite3_free(zSql);
674 if( rc ) return rc;
675 editDist3ConfigClear(p);
676 while( sqlite3_step(pStmt)==SQLITE_ROW ){
677 int iLang = sqlite3_column_int(pStmt, 0);
678 const char *zFrom = (const char*)sqlite3_column_text(pStmt, 1);
679 int nFrom = zFrom ? sqlite3_column_bytes(pStmt, 1) : 0;
680 const char *zTo = (const char*)sqlite3_column_text(pStmt, 2);
681 int nTo = zTo ? sqlite3_column_bytes(pStmt, 2) : 0;
682 int iCost = sqlite3_column_int(pStmt, 3);
683
684 assert( zFrom!=0 || nFrom==0 );
685 assert( zTo!=0 || nTo==0 );
686 if( nFrom>100 || nTo>100 ) continue;
687 if( iCost<0 ) continue;
688 if( pLang==0 || iLang!=iLangPrev ){
689 EditDist3Lang *pNew;
690 pNew = sqlite3_realloc(p->a, (p->nLang+1)*sizeof(p->a[0]));
691 if( pNew==0 ){ rc = SQLITE_NOMEM; break; }
692 p->a = pNew;
693 pLang = &p->a[p->nLang];
694 p->nLang++;
695 pLang->iLang = iLang;
696 pLang->iInsCost = 100;
697 pLang->iDelCost = 100;
698 pLang->iSubCost = 150;
699 pLang->pCost = 0;
700 iLangPrev = iLang;
701 }
702 if( nFrom==1 && zFrom[0]=='?' && nTo==0 ){
703 pLang->iDelCost = iCost;
704 }else if( nFrom==0 && nTo==1 && zTo[0]=='?' ){
705 pLang->iInsCost = iCost;
706 }else if( nFrom==1 && nTo==1 && zFrom[0]=='?' && zTo[0]=='?' ){
707 pLang->iSubCost = iCost;
708 }else{
709 EditDist3Cost *pCost;
710 int nExtra = nFrom + nTo - 4;
711 if( nExtra<0 ) nExtra = 0;
712 pCost = sqlite3_malloc( sizeof(*pCost) + nExtra );
713 if( pCost==0 ){ rc = SQLITE_NOMEM; break; }
714 pCost->nFrom = nFrom;
715 pCost->nTo = nTo;
716 pCost->iCost = iCost;
717 memcpy(pCost->a, zFrom, nFrom);
718 memcpy(pCost->a + nFrom, zTo, nTo);
719 pCost->pNext = pLang->pCost;
720 pLang->pCost = pCost;
721 }
722 }
723 rc2 = sqlite3_finalize(pStmt);
724 if( rc==SQLITE_OK ) rc = rc2;
725 return rc;
726 }
727
728 /*
729 ** Return the length (in bytes) of a utf-8 character. Or return a maximum
730 ** of N.
731 */
732 static int utf8Len(unsigned char c, int N){
733 int len = 1;
734 if( c>0x7f ){
735 if( (c&0xe0)==0xc0 ){
736 len = 2;
737 }else if( (c&0xf0)==0xe0 ){
738 len = 3;
739 }else{
740 len = 4;
741 }
742 }
743 if( len>N ) len = N;
744 return len;
745 }
746
747 /*
748 ** Return TRUE (non-zero) if the To side of the given cost matches
749 ** the given string.
750 */
751 static int matchTo(EditDist3Cost *p, const char *z, int n){
752 if( p->nTo>n ) return 0;
753 if( strncmp(p->a+p->nFrom, z, p->nTo)!=0 ) return 0;
754 return 1;
755 }
756
757 /*
758 ** Return TRUE (non-zero) if the From side of the given cost matches
759 ** the given string.
760 */
761 static int matchFrom(EditDist3Cost *p, const char *z, int n){
762 assert( p->nFrom<=n );
763 if( strncmp(p->a, z, p->nFrom)!=0 ) return 0;
764 return 1;
765 }
766
767 /*
768 ** Return TRUE (non-zero) of the next FROM character and the next TO
769 ** character are the same.
770 */
771 static int matchFromTo(
772 EditDist3FromString *pStr, /* Left hand string */
773 int n1, /* Index of comparison character on the left */
774 const char *z2, /* Right-handl comparison character */
775 int n2 /* Bytes remaining in z2[] */
776 ){
777 int b1 = pStr->a[n1].nByte;
778 if( b1>n2 ) return 0;
779 if( memcmp(pStr->z+n1, z2, b1)!=0 ) return 0;
780 return 1;
781 }
782
783 /*
784 ** Delete an EditDist3FromString objecct
785 */
786 static void editDist3FromStringDelete(EditDist3FromString *p){
787 int i;
788 if( p ){
789 for(i=0; i<p->n; i++){
790 sqlite3_free(p->a[i].apDel);
791 sqlite3_free(p->a[i].apSubst);
792 }
793 sqlite3_free(p);
794 }
795 }
796
797 /*
798 ** Create a EditDist3FromString object.
799 */
800 static EditDist3FromString *editDist3FromStringNew(
801 const EditDist3Lang *pLang,
802 const char *z,
803 int n
804 ){
805 EditDist3FromString *pStr;
806 EditDist3Cost *p;
807 int i;
808
809 if( z==0 ) return 0;
810 if( n<0 ) n = (int)strlen(z);
811 pStr = sqlite3_malloc( sizeof(*pStr) + sizeof(pStr->a[0])*n + n + 1 );
812 if( pStr==0 ) return 0;
813 pStr->a = (EditDist3From*)&pStr[1];
814 memset(pStr->a, 0, sizeof(pStr->a[0])*n);
815 pStr->n = n;
816 pStr->z = (char*)&pStr->a[n];
817 memcpy(pStr->z, z, n+1);
818 if( n && z[n-1]=='*' ){
819 pStr->isPrefix = 1;
820 n--;
821 pStr->n--;
822 pStr->z[n] = 0;
823 }else{
824 pStr->isPrefix = 0;
825 }
826
827 for(i=0; i<n; i++){
828 EditDist3From *pFrom = &pStr->a[i];
829 memset(pFrom, 0, sizeof(*pFrom));
830 pFrom->nByte = utf8Len((unsigned char)z[i], n-i);
831 for(p=pLang->pCost; p; p=p->pNext){
832 EditDist3Cost **apNew;
833 if( i+p->nFrom>n ) continue;
834 if( matchFrom(p, z+i, n-i)==0 ) continue;
835 if( p->nTo==0 ){
836 apNew = sqlite3_realloc(pFrom->apDel,
837 sizeof(*apNew)*(pFrom->nDel+1));
838 if( apNew==0 ) break;
839 pFrom->apDel = apNew;
840 apNew[pFrom->nDel++] = p;
841 }else{
842 apNew = sqlite3_realloc(pFrom->apSubst,
843 sizeof(*apNew)*(pFrom->nSubst+1));
844 if( apNew==0 ) break;
845 pFrom->apSubst = apNew;
846 apNew[pFrom->nSubst++] = p;
847 }
848 }
849 if( p ){
850 editDist3FromStringDelete(pStr);
851 pStr = 0;
852 break;
853 }
854 }
855 return pStr;
856 }
857
858 /*
859 ** Update entry m[i] such that it is the minimum of its current value
860 ** and m[j]+iCost.
861 **
862 ** If the iCost is 1,000,000 or greater, then consider the cost to be
863 ** infinite and skip the update.
864 */
865 static void updateCost(
866 unsigned int *m,
867 int i,
868 int j,
869 int iCost
870 ){
871 assert( iCost>=0 );
872 if( iCost<10000 ){
873 unsigned int b = m[j] + iCost;
874 if( b<m[i] ) m[i] = b;
875 }
876 }
877
878 /* Compute the edit distance between two strings.
879 **
880 ** If an error occurs, return a negative number which is the error code.
881 **
882 ** If pnMatch is not NULL, then *pnMatch is set to the number of characters
883 ** (not bytes) in z2 that matched the search pattern in *pFrom. If pFrom does
884 ** not contain the pattern for a prefix-search, then this is always the number
885 ** of characters in z2. If pFrom does contain a prefix search pattern, then
886 ** it is the number of characters in the prefix of z2 that was deemed to
887 ** match pFrom.
888 */
889 static int editDist3Core(
890 EditDist3FromString *pFrom, /* The FROM string */
891 const char *z2, /* The TO string */
892 int n2, /* Length of the TO string */
893 const EditDist3Lang *pLang, /* Edit weights for a particular language ID */
894 int *pnMatch /* OUT: Characters in matched prefix */
895 ){
896 int k, n;
897 int i1, b1;
898 int i2, b2;
899 EditDist3FromString f = *pFrom;
900 EditDist3To *a2;
901 unsigned int *m;
902 int szRow;
903 EditDist3Cost *p;
904 int res;
905
906 /* allocate the Wagner matrix and the aTo[] array for the TO string */
907 n = (f.n+1)*(n2+1);
908 n = (n+1)&~1;
909 m = sqlite3_malloc( n*sizeof(m[0]) + sizeof(a2[0])*n2 );
910 if( m==0 ) return -1; /* Out of memory */
911 a2 = (EditDist3To*)&m[n];
912 memset(a2, 0, sizeof(a2[0])*n2);
913
914 /* Fill in the a1[] matrix for all characters of the TO string */
915 for(i2=0; i2<n2; i2++){
916 a2[i2].nByte = utf8Len((unsigned char)z2[i2], n2-i2);
917 for(p=pLang->pCost; p; p=p->pNext){
918 EditDist3Cost **apNew;
919 if( p->nFrom>0 ) continue;
920 if( i2+p->nTo>n2 ) continue;
921 if( matchTo(p, z2+i2, n2-i2)==0 ) continue;
922 a2[i2].nIns++;
923 apNew = sqlite3_realloc(a2[i2].apIns, sizeof(*apNew)*a2[i2].nIns);
924 if( apNew==0 ){
925 res = -1; /* Out of memory */
926 goto editDist3Abort;
927 }
928 a2[i2].apIns = apNew;
929 a2[i2].apIns[a2[i2].nIns-1] = p;
930 }
931 }
932
933 /* Prepare to compute the minimum edit distance */
934 szRow = f.n+1;
935 memset(m, 0x01, (n2+1)*szRow*sizeof(m[0]));
936 m[0] = 0;
937
938 /* First fill in the top-row of the matrix with FROM deletion costs */
939 for(i1=0; i1<f.n; i1 += b1){
940 b1 = f.a[i1].nByte;
941 updateCost(m, i1+b1, i1, pLang->iDelCost);
942 for(k=0; k<f.a[i1].nDel; k++){
943 p = f.a[i1].apDel[k];
944 updateCost(m, i1+p->nFrom, i1, p->iCost);
945 }
946 }
947
948 /* Fill in all subsequent rows, top-to-bottom, left-to-right */
949 for(i2=0; i2<n2; i2 += b2){
950 int rx; /* Starting index for current row */
951 int rxp; /* Starting index for previous row */
952 b2 = a2[i2].nByte;
953 rx = szRow*(i2+b2);
954 rxp = szRow*i2;
955 updateCost(m, rx, rxp, pLang->iInsCost);
956 for(k=0; k<a2[i2].nIns; k++){
957 p = a2[i2].apIns[k];
958 updateCost(m, szRow*(i2+p->nTo), rxp, p->iCost);
959 }
960 for(i1=0; i1<f.n; i1+=b1){
961 int cx; /* Index of current cell */
962 int cxp; /* Index of cell immediately to the left */
963 int cxd; /* Index of cell to the left and one row above */
964 int cxu; /* Index of cell immediately above */
965 b1 = f.a[i1].nByte;
966 cxp = rx + i1;
967 cx = cxp + b1;
968 cxd = rxp + i1;
969 cxu = cxd + b1;
970 updateCost(m, cx, cxp, pLang->iDelCost);
971 for(k=0; k<f.a[i1].nDel; k++){
972 p = f.a[i1].apDel[k];
973 updateCost(m, cxp+p->nFrom, cxp, p->iCost);
974 }
975 updateCost(m, cx, cxu, pLang->iInsCost);
976 if( matchFromTo(&f, i1, z2+i2, n2-i2) ){
977 updateCost(m, cx, cxd, 0);
978 }
979 updateCost(m, cx, cxd, pLang->iSubCost);
980 for(k=0; k<f.a[i1].nSubst; k++){
981 p = f.a[i1].apSubst[k];
982 if( matchTo(p, z2+i2, n2-i2) ){
983 updateCost(m, cxd+p->nFrom+szRow*p->nTo, cxd, p->iCost);
984 }
985 }
986 }
987 }
988
989 #if 0 /* Enable for debugging */
990 printf(" ^");
991 for(i1=0; i1<f.n; i1++) printf(" %c-%2x", f.z[i1], f.z[i1]&0xff);
992 printf("\n ^:");
993 for(i1=0; i1<szRow; i1++){
994 int v = m[i1];
995 if( v>9999 ) printf(" ****");
996 else printf(" %4d", v);
997 }
998 printf("\n");
999 for(i2=0; i2<n2; i2++){
1000 printf("%c-%02x:", z2[i2], z2[i2]&0xff);
1001 for(i1=0; i1<szRow; i1++){
1002 int v = m[(i2+1)*szRow+i1];
1003 if( v>9999 ) printf(" ****");
1004 else printf(" %4d", v);
1005 }
1006 printf("\n");
1007 }
1008 #endif
1009
1010 /* Free memory allocations and return the result */
1011 res = (int)m[szRow*(n2+1)-1];
1012 n = n2;
1013 if( f.isPrefix ){
1014 for(i2=1; i2<=n2; i2++){
1015 int b = m[szRow*i2-1];
1016 if( b<=res ){
1017 res = b;
1018 n = i2 - 1;
1019 }
1020 }
1021 }
1022 if( pnMatch ){
1023 int nExtra = 0;
1024 for(k=0; k<n; k++){
1025 if( (z2[k] & 0xc0)==0x80 ) nExtra++;
1026 }
1027 *pnMatch = n - nExtra;
1028 }
1029
1030 editDist3Abort:
1031 for(i2=0; i2<n2; i2++) sqlite3_free(a2[i2].apIns);
1032 sqlite3_free(m);
1033 return res;
1034 }
1035
1036 /*
1037 ** Get an appropriate EditDist3Lang object.
1038 */
1039 static const EditDist3Lang *editDist3FindLang(
1040 EditDist3Config *pConfig,
1041 int iLang
1042 ){
1043 int i;
1044 for(i=0; i<pConfig->nLang; i++){
1045 if( pConfig->a[i].iLang==iLang ) return &pConfig->a[i];
1046 }
1047 return &editDist3Lang;
1048 }
1049
1050 /*
1051 ** Function: editdist3(A,B,iLang)
1052 ** editdist3(tablename)
1053 **
1054 ** Return the cost of transforming string A into string B using edit
1055 ** weights for iLang.
1056 **
1057 ** The second form loads edit weights into memory from a table.
1058 */
1059 static void editDist3SqlFunc(
1060 sqlite3_context *context,
1061 int argc,
1062 sqlite3_value **argv
1063 ){
1064 EditDist3Config *pConfig = (EditDist3Config*)sqlite3_user_data(context);
1065 sqlite3 *db = sqlite3_context_db_handle(context);
1066 int rc;
1067 if( argc==1 ){
1068 const char *zTable = (const char*)sqlite3_value_text(argv[0]);
1069 rc = editDist3ConfigLoad(pConfig, db, zTable);
1070 if( rc ) sqlite3_result_error_code(context, rc);
1071 }else{
1072 const char *zA = (const char*)sqlite3_value_text(argv[0]);
1073 const char *zB = (const char*)sqlite3_value_text(argv[1]);
1074 int nA = sqlite3_value_bytes(argv[0]);
1075 int nB = sqlite3_value_bytes(argv[1]);
1076 int iLang = argc==3 ? sqlite3_value_int(argv[2]) : 0;
1077 const EditDist3Lang *pLang = editDist3FindLang(pConfig, iLang);
1078 EditDist3FromString *pFrom;
1079 int dist;
1080
1081 pFrom = editDist3FromStringNew(pLang, zA, nA);
1082 if( pFrom==0 ){
1083 sqlite3_result_error_nomem(context);
1084 return;
1085 }
1086 dist = editDist3Core(pFrom, zB, nB, pLang, 0);
1087 editDist3FromStringDelete(pFrom);
1088 if( dist==(-1) ){
1089 sqlite3_result_error_nomem(context);
1090 }else{
1091 sqlite3_result_int(context, dist);
1092 }
1093 }
1094 }
1095
1096 /*
1097 ** Register the editDist3 function with SQLite
1098 */
1099 static int editDist3Install(sqlite3 *db){
1100 int rc;
1101 EditDist3Config *pConfig = sqlite3_malloc( sizeof(*pConfig) );
1102 if( pConfig==0 ) return SQLITE_NOMEM;
1103 memset(pConfig, 0, sizeof(*pConfig));
1104 rc = sqlite3_create_function_v2(db, "editdist3",
1105 2, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0);
1106 if( rc==SQLITE_OK ){
1107 rc = sqlite3_create_function_v2(db, "editdist3",
1108 3, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0);
1109 }
1110 if( rc==SQLITE_OK ){
1111 rc = sqlite3_create_function_v2(db, "editdist3",
1112 1, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0,
1113 editDist3ConfigDelete);
1114 }else{
1115 sqlite3_free(pConfig);
1116 }
1117 return rc;
1118 }
1119 /* End configurable cost unicode edit distance routines
1120 ******************************************************************************
1121 ******************************************************************************
1122 ** Begin transliterate unicode-to-ascii implementation
1123 */
1124
1125 #if !SQLITE_AMALGAMATION
1126 /*
1127 ** This lookup table is used to help decode the first byte of
1128 ** a multi-byte UTF8 character.
1129 */
1130 static const unsigned char sqlite3Utf8Trans1[] = {
1131 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
1132 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
1133 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
1134 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
1135 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
1136 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
1137 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
1138 0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
1139 };
1140 #endif
1141
1142 /*
1143 ** Return the value of the first UTF-8 character in the string.
1144 */
1145 static int utf8Read(const unsigned char *z, int n, int *pSize){
1146 int c, i;
1147
1148 /* All callers to this routine (in the current implementation)
1149 ** always have n>0. */
1150 if( NEVER(n==0) ){
1151 c = i = 0;
1152 }else{
1153 c = z[0];
1154 i = 1;
1155 if( c>=0xc0 ){
1156 c = sqlite3Utf8Trans1[c-0xc0];
1157 while( i<n && (z[i] & 0xc0)==0x80 ){
1158 c = (c<<6) + (0x3f & z[i++]);
1159 }
1160 }
1161 }
1162 *pSize = i;
1163 return c;
1164 }
1165
1166 /*
1167 ** Return the number of characters in the utf-8 string in the nIn byte
1168 ** buffer pointed to by zIn.
1169 */
1170 static int utf8Charlen(const char *zIn, int nIn){
1171 int i;
1172 int nChar = 0;
1173 for(i=0; i<nIn; nChar++){
1174 int sz;
1175 utf8Read((const unsigned char *)&zIn[i], nIn-i, &sz);
1176 i += sz;
1177 }
1178 return nChar;
1179 }
1180
1181 /*
1182 ** Table of translations from unicode characters into ASCII.
1183 */
1184 static const struct {
1185 unsigned short int cFrom;
1186 unsigned char cTo0, cTo1;
1187 } translit[] = {
1188 { 0x00A0, 0x20, 0x00 }, /*   to */
1189 { 0x00B5, 0x75, 0x00 }, /* µ to u */
1190 { 0x00C0, 0x41, 0x00 }, /* À to A */
1191 { 0x00C1, 0x41, 0x00 }, /* Á to A */
1192 { 0x00C2, 0x41, 0x00 }, /* Â to A */
1193 { 0x00C3, 0x41, 0x00 }, /* Ã to A */
1194 { 0x00C4, 0x41, 0x65 }, /* Ä to Ae */
1195 { 0x00C5, 0x41, 0x61 }, /* Å to Aa */
1196 { 0x00C6, 0x41, 0x45 }, /* Æ to AE */
1197 { 0x00C7, 0x43, 0x00 }, /* Ç to C */
1198 { 0x00C8, 0x45, 0x00 }, /* È to E */
1199 { 0x00C9, 0x45, 0x00 }, /* É to E */
1200 { 0x00CA, 0x45, 0x00 }, /* Ê to E */
1201 { 0x00CB, 0x45, 0x00 }, /* Ë to E */
1202 { 0x00CC, 0x49, 0x00 }, /* Ì to I */
1203 { 0x00CD, 0x49, 0x00 }, /* Í to I */
1204 { 0x00CE, 0x49, 0x00 }, /* Î to I */
1205 { 0x00CF, 0x49, 0x00 }, /* Ï to I */
1206 { 0x00D0, 0x44, 0x00 }, /* Ð to D */
1207 { 0x00D1, 0x4E, 0x00 }, /* Ñ to N */
1208 { 0x00D2, 0x4F, 0x00 }, /* Ò to O */
1209 { 0x00D3, 0x4F, 0x00 }, /* Ó to O */
1210 { 0x00D4, 0x4F, 0x00 }, /* Ô to O */
1211 { 0x00D5, 0x4F, 0x00 }, /* Õ to O */
1212 { 0x00D6, 0x4F, 0x65 }, /* Ö to Oe */
1213 { 0x00D7, 0x78, 0x00 }, /* × to x */
1214 { 0x00D8, 0x4F, 0x00 }, /* Ø to O */
1215 { 0x00D9, 0x55, 0x00 }, /* Ù to U */
1216 { 0x00DA, 0x55, 0x00 }, /* Ú to U */
1217 { 0x00DB, 0x55, 0x00 }, /* Û to U */
1218 { 0x00DC, 0x55, 0x65 }, /* Ü to Ue */
1219 { 0x00DD, 0x59, 0x00 }, /* Ý to Y */
1220 { 0x00DE, 0x54, 0x68 }, /* Þ to Th */
1221 { 0x00DF, 0x73, 0x73 }, /* ß to ss */
1222 { 0x00E0, 0x61, 0x00 }, /* à to a */
1223 { 0x00E1, 0x61, 0x00 }, /* á to a */
1224 { 0x00E2, 0x61, 0x00 }, /* â to a */
1225 { 0x00E3, 0x61, 0x00 }, /* ã to a */
1226 { 0x00E4, 0x61, 0x65 }, /* ä to ae */
1227 { 0x00E5, 0x61, 0x61 }, /* å to aa */
1228 { 0x00E6, 0x61, 0x65 }, /* æ to ae */
1229 { 0x00E7, 0x63, 0x00 }, /* ç to c */
1230 { 0x00E8, 0x65, 0x00 }, /* è to e */
1231 { 0x00E9, 0x65, 0x00 }, /* é to e */
1232 { 0x00EA, 0x65, 0x00 }, /* ê to e */
1233 { 0x00EB, 0x65, 0x00 }, /* ë to e */
1234 { 0x00EC, 0x69, 0x00 }, /* ì to i */
1235 { 0x00ED, 0x69, 0x00 }, /* í to i */
1236 { 0x00EE, 0x69, 0x00 }, /* î to i */
1237 { 0x00EF, 0x69, 0x00 }, /* ï to i */
1238 { 0x00F0, 0x64, 0x00 }, /* ð to d */
1239 { 0x00F1, 0x6E, 0x00 }, /* ñ to n */
1240 { 0x00F2, 0x6F, 0x00 }, /* ò to o */
1241 { 0x00F3, 0x6F, 0x00 }, /* ó to o */
1242 { 0x00F4, 0x6F, 0x00 }, /* ô to o */
1243 { 0x00F5, 0x6F, 0x00 }, /* õ to o */
1244 { 0x00F6, 0x6F, 0x65 }, /* ö to oe */
1245 { 0x00F7, 0x3A, 0x00 }, /* ÷ to : */
1246 { 0x00F8, 0x6F, 0x00 }, /* ø to o */
1247 { 0x00F9, 0x75, 0x00 }, /* ù to u */
1248 { 0x00FA, 0x75, 0x00 }, /* ú to u */
1249 { 0x00FB, 0x75, 0x00 }, /* û to u */
1250 { 0x00FC, 0x75, 0x65 }, /* ü to ue */
1251 { 0x00FD, 0x79, 0x00 }, /* ý to y */
1252 { 0x00FE, 0x74, 0x68 }, /* þ to th */
1253 { 0x00FF, 0x79, 0x00 }, /* ÿ to y */
1254 { 0x0100, 0x41, 0x00 }, /* Ā to A */
1255 { 0x0101, 0x61, 0x00 }, /* ā to a */
1256 { 0x0102, 0x41, 0x00 }, /* Ă to A */
1257 { 0x0103, 0x61, 0x00 }, /* ă to a */
1258 { 0x0104, 0x41, 0x00 }, /* Ą to A */
1259 { 0x0105, 0x61, 0x00 }, /* ą to a */
1260 { 0x0106, 0x43, 0x00 }, /* Ć to C */
1261 { 0x0107, 0x63, 0x00 }, /* ć to c */
1262 { 0x0108, 0x43, 0x68 }, /* Ĉ to Ch */
1263 { 0x0109, 0x63, 0x68 }, /* ĉ to ch */
1264 { 0x010A, 0x43, 0x00 }, /* Ċ to C */
1265 { 0x010B, 0x63, 0x00 }, /* ċ to c */
1266 { 0x010C, 0x43, 0x00 }, /* Č to C */
1267 { 0x010D, 0x63, 0x00 }, /* č to c */
1268 { 0x010E, 0x44, 0x00 }, /* Ď to D */
1269 { 0x010F, 0x64, 0x00 }, /* ď to d */
1270 { 0x0110, 0x44, 0x00 }, /* Đ to D */
1271 { 0x0111, 0x64, 0x00 }, /* đ to d */
1272 { 0x0112, 0x45, 0x00 }, /* Ē to E */
1273 { 0x0113, 0x65, 0x00 }, /* ē to e */
1274 { 0x0114, 0x45, 0x00 }, /* Ĕ to E */
1275 { 0x0115, 0x65, 0x00 }, /* ĕ to e */
1276 { 0x0116, 0x45, 0x00 }, /* Ė to E */
1277 { 0x0117, 0x65, 0x00 }, /* ė to e */
1278 { 0x0118, 0x45, 0x00 }, /* Ę to E */
1279 { 0x0119, 0x65, 0x00 }, /* ę to e */
1280 { 0x011A, 0x45, 0x00 }, /* Ě to E */
1281 { 0x011B, 0x65, 0x00 }, /* ě to e */
1282 { 0x011C, 0x47, 0x68 }, /* Ĝ to Gh */
1283 { 0x011D, 0x67, 0x68 }, /* ĝ to gh */
1284 { 0x011E, 0x47, 0x00 }, /* Ğ to G */
1285 { 0x011F, 0x67, 0x00 }, /* ğ to g */
1286 { 0x0120, 0x47, 0x00 }, /* Ġ to G */
1287 { 0x0121, 0x67, 0x00 }, /* ġ to g */
1288 { 0x0122, 0x47, 0x00 }, /* Ģ to G */
1289 { 0x0123, 0x67, 0x00 }, /* ģ to g */
1290 { 0x0124, 0x48, 0x68 }, /* Ĥ to Hh */
1291 { 0x0125, 0x68, 0x68 }, /* ĥ to hh */
1292 { 0x0126, 0x48, 0x00 }, /* Ħ to H */
1293 { 0x0127, 0x68, 0x00 }, /* ħ to h */
1294 { 0x0128, 0x49, 0x00 }, /* Ĩ to I */
1295 { 0x0129, 0x69, 0x00 }, /* ĩ to i */
1296 { 0x012A, 0x49, 0x00 }, /* Ī to I */
1297 { 0x012B, 0x69, 0x00 }, /* ī to i */
1298 { 0x012C, 0x49, 0x00 }, /* Ĭ to I */
1299 { 0x012D, 0x69, 0x00 }, /* ĭ to i */
1300 { 0x012E, 0x49, 0x00 }, /* Į to I */
1301 { 0x012F, 0x69, 0x00 }, /* į to i */
1302 { 0x0130, 0x49, 0x00 }, /* İ to I */
1303 { 0x0131, 0x69, 0x00 }, /* ı to i */
1304 { 0x0132, 0x49, 0x4A }, /* IJ to IJ */
1305 { 0x0133, 0x69, 0x6A }, /* ij to ij */
1306 { 0x0134, 0x4A, 0x68 }, /* Ĵ to Jh */
1307 { 0x0135, 0x6A, 0x68 }, /* ĵ to jh */
1308 { 0x0136, 0x4B, 0x00 }, /* Ķ to K */
1309 { 0x0137, 0x6B, 0x00 }, /* ķ to k */
1310 { 0x0138, 0x6B, 0x00 }, /* ĸ to k */
1311 { 0x0139, 0x4C, 0x00 }, /* Ĺ to L */
1312 { 0x013A, 0x6C, 0x00 }, /* ĺ to l */
1313 { 0x013B, 0x4C, 0x00 }, /* Ļ to L */
1314 { 0x013C, 0x6C, 0x00 }, /* ļ to l */
1315 { 0x013D, 0x4C, 0x00 }, /* Ľ to L */
1316 { 0x013E, 0x6C, 0x00 }, /* ľ to l */
1317 { 0x013F, 0x4C, 0x2E }, /* Ŀ to L. */
1318 { 0x0140, 0x6C, 0x2E }, /* ŀ to l. */
1319 { 0x0141, 0x4C, 0x00 }, /* Ł to L */
1320 { 0x0142, 0x6C, 0x00 }, /* ł to l */
1321 { 0x0143, 0x4E, 0x00 }, /* Ń to N */
1322 { 0x0144, 0x6E, 0x00 }, /* ń to n */
1323 { 0x0145, 0x4E, 0x00 }, /* Ņ to N */
1324 { 0x0146, 0x6E, 0x00 }, /* ņ to n */
1325 { 0x0147, 0x4E, 0x00 }, /* Ň to N */
1326 { 0x0148, 0x6E, 0x00 }, /* ň to n */
1327 { 0x0149, 0x27, 0x6E }, /* ʼn to 'n */
1328 { 0x014A, 0x4E, 0x47 }, /* Ŋ to NG */
1329 { 0x014B, 0x6E, 0x67 }, /* ŋ to ng */
1330 { 0x014C, 0x4F, 0x00 }, /* Ō to O */
1331 { 0x014D, 0x6F, 0x00 }, /* ō to o */
1332 { 0x014E, 0x4F, 0x00 }, /* Ŏ to O */
1333 { 0x014F, 0x6F, 0x00 }, /* ŏ to o */
1334 { 0x0150, 0x4F, 0x00 }, /* Ő to O */
1335 { 0x0151, 0x6F, 0x00 }, /* ő to o */
1336 { 0x0152, 0x4F, 0x45 }, /* Πto OE */
1337 { 0x0153, 0x6F, 0x65 }, /* œ to oe */
1338 { 0x0154, 0x52, 0x00 }, /* Ŕ to R */
1339 { 0x0155, 0x72, 0x00 }, /* ŕ to r */
1340 { 0x0156, 0x52, 0x00 }, /* Ŗ to R */
1341 { 0x0157, 0x72, 0x00 }, /* ŗ to r */
1342 { 0x0158, 0x52, 0x00 }, /* Ř to R */
1343 { 0x0159, 0x72, 0x00 }, /* ř to r */
1344 { 0x015A, 0x53, 0x00 }, /* Ś to S */
1345 { 0x015B, 0x73, 0x00 }, /* ś to s */
1346 { 0x015C, 0x53, 0x68 }, /* Ŝ to Sh */
1347 { 0x015D, 0x73, 0x68 }, /* ŝ to sh */
1348 { 0x015E, 0x53, 0x00 }, /* Ş to S */
1349 { 0x015F, 0x73, 0x00 }, /* ş to s */
1350 { 0x0160, 0x53, 0x00 }, /* Š to S */
1351 { 0x0161, 0x73, 0x00 }, /* š to s */
1352 { 0x0162, 0x54, 0x00 }, /* Ţ to T */
1353 { 0x0163, 0x74, 0x00 }, /* ţ to t */
1354 { 0x0164, 0x54, 0x00 }, /* Ť to T */
1355 { 0x0165, 0x74, 0x00 }, /* ť to t */
1356 { 0x0166, 0x54, 0x00 }, /* Ŧ to T */
1357 { 0x0167, 0x74, 0x00 }, /* ŧ to t */
1358 { 0x0168, 0x55, 0x00 }, /* Ũ to U */
1359 { 0x0169, 0x75, 0x00 }, /* ũ to u */
1360 { 0x016A, 0x55, 0x00 }, /* Ū to U */
1361 { 0x016B, 0x75, 0x00 }, /* ū to u */
1362 { 0x016C, 0x55, 0x00 }, /* Ŭ to U */
1363 { 0x016D, 0x75, 0x00 }, /* ŭ to u */
1364 { 0x016E, 0x55, 0x00 }, /* Ů to U */
1365 { 0x016F, 0x75, 0x00 }, /* ů to u */
1366 { 0x0170, 0x55, 0x00 }, /* Ű to U */
1367 { 0x0171, 0x75, 0x00 }, /* ű to u */
1368 { 0x0172, 0x55, 0x00 }, /* Ų to U */
1369 { 0x0173, 0x75, 0x00 }, /* ų to u */
1370 { 0x0174, 0x57, 0x00 }, /* Ŵ to W */
1371 { 0x0175, 0x77, 0x00 }, /* ŵ to w */
1372 { 0x0176, 0x59, 0x00 }, /* Ŷ to Y */
1373 { 0x0177, 0x79, 0x00 }, /* ŷ to y */
1374 { 0x0178, 0x59, 0x00 }, /* Ÿ to Y */
1375 { 0x0179, 0x5A, 0x00 }, /* Ź to Z */
1376 { 0x017A, 0x7A, 0x00 }, /* ź to z */
1377 { 0x017B, 0x5A, 0x00 }, /* Ż to Z */
1378 { 0x017C, 0x7A, 0x00 }, /* ż to z */
1379 { 0x017D, 0x5A, 0x00 }, /* Ž to Z */
1380 { 0x017E, 0x7A, 0x00 }, /* ž to z */
1381 { 0x017F, 0x73, 0x00 }, /* ſ to s */
1382 { 0x0192, 0x66, 0x00 }, /* ƒ to f */
1383 { 0x0218, 0x53, 0x00 }, /* Ș to S */
1384 { 0x0219, 0x73, 0x00 }, /* ș to s */
1385 { 0x021A, 0x54, 0x00 }, /* Ț to T */
1386 { 0x021B, 0x74, 0x00 }, /* ț to t */
1387 { 0x0386, 0x41, 0x00 }, /* Ά to A */
1388 { 0x0388, 0x45, 0x00 }, /* Έ to E */
1389 { 0x0389, 0x49, 0x00 }, /* Ή to I */
1390 { 0x038A, 0x49, 0x00 }, /* Ί to I */
1391 { 0x038C, 0x4f, 0x00 }, /* Ό to O */
1392 { 0x038E, 0x59, 0x00 }, /* Ύ to Y */
1393 { 0x038F, 0x4f, 0x00 }, /* Ώ to O */
1394 { 0x0390, 0x69, 0x00 }, /* ΐ to i */
1395 { 0x0391, 0x41, 0x00 }, /* Α to A */
1396 { 0x0392, 0x42, 0x00 }, /* Β to B */
1397 { 0x0393, 0x47, 0x00 }, /* Γ to G */
1398 { 0x0394, 0x44, 0x00 }, /* Δ to D */
1399 { 0x0395, 0x45, 0x00 }, /* Ε to E */
1400 { 0x0396, 0x5a, 0x00 }, /* Ζ to Z */
1401 { 0x0397, 0x49, 0x00 }, /* Η to I */
1402 { 0x0398, 0x54, 0x68 }, /* Θ to Th */
1403 { 0x0399, 0x49, 0x00 }, /* Ι to I */
1404 { 0x039A, 0x4b, 0x00 }, /* Κ to K */
1405 { 0x039B, 0x4c, 0x00 }, /* Λ to L */
1406 { 0x039C, 0x4d, 0x00 }, /* Μ to M */
1407 { 0x039D, 0x4e, 0x00 }, /* Ν to N */
1408 { 0x039E, 0x58, 0x00 }, /* Ξ to X */
1409 { 0x039F, 0x4f, 0x00 }, /* Ο to O */
1410 { 0x03A0, 0x50, 0x00 }, /* Π to P */
1411 { 0x03A1, 0x52, 0x00 }, /* Ρ to R */
1412 { 0x03A3, 0x53, 0x00 }, /* Σ to S */
1413 { 0x03A4, 0x54, 0x00 }, /* Τ to T */
1414 { 0x03A5, 0x59, 0x00 }, /* Υ to Y */
1415 { 0x03A6, 0x46, 0x00 }, /* Φ to F */
1416 { 0x03A7, 0x43, 0x68 }, /* Χ to Ch */
1417 { 0x03A8, 0x50, 0x73 }, /* Ψ to Ps */
1418 { 0x03A9, 0x4f, 0x00 }, /* Ω to O */
1419 { 0x03AA, 0x49, 0x00 }, /* Ϊ to I */
1420 { 0x03AB, 0x59, 0x00 }, /* Ϋ to Y */
1421 { 0x03AC, 0x61, 0x00 }, /* ά to a */
1422 { 0x03AD, 0x65, 0x00 }, /* έ to e */
1423 { 0x03AE, 0x69, 0x00 }, /* ή to i */
1424 { 0x03AF, 0x69, 0x00 }, /* ί to i */
1425 { 0x03B1, 0x61, 0x00 }, /* α to a */
1426 { 0x03B2, 0x62, 0x00 }, /* β to b */
1427 { 0x03B3, 0x67, 0x00 }, /* γ to g */
1428 { 0x03B4, 0x64, 0x00 }, /* δ to d */
1429 { 0x03B5, 0x65, 0x00 }, /* ε to e */
1430 { 0x03B6, 0x7a, 0x00 }, /* ζ to z */
1431 { 0x03B7, 0x69, 0x00 }, /* η to i */
1432 { 0x03B8, 0x74, 0x68 }, /* θ to th */
1433 { 0x03B9, 0x69, 0x00 }, /* ι to i */
1434 { 0x03BA, 0x6b, 0x00 }, /* κ to k */
1435 { 0x03BB, 0x6c, 0x00 }, /* λ to l */
1436 { 0x03BC, 0x6d, 0x00 }, /* μ to m */
1437 { 0x03BD, 0x6e, 0x00 }, /* ν to n */
1438 { 0x03BE, 0x78, 0x00 }, /* ξ to x */
1439 { 0x03BF, 0x6f, 0x00 }, /* ο to o */
1440 { 0x03C0, 0x70, 0x00 }, /* π to p */
1441 { 0x03C1, 0x72, 0x00 }, /* ρ to r */
1442 { 0x03C3, 0x73, 0x00 }, /* σ to s */
1443 { 0x03C4, 0x74, 0x00 }, /* τ to t */
1444 { 0x03C5, 0x79, 0x00 }, /* υ to y */
1445 { 0x03C6, 0x66, 0x00 }, /* φ to f */
1446 { 0x03C7, 0x63, 0x68 }, /* χ to ch */
1447 { 0x03C8, 0x70, 0x73 }, /* ψ to ps */
1448 { 0x03C9, 0x6f, 0x00 }, /* ω to o */
1449 { 0x03CA, 0x69, 0x00 }, /* ϊ to i */
1450 { 0x03CB, 0x79, 0x00 }, /* ϋ to y */
1451 { 0x03CC, 0x6f, 0x00 }, /* ό to o */
1452 { 0x03CD, 0x79, 0x00 }, /* ύ to y */
1453 { 0x03CE, 0x69, 0x00 }, /* ώ to i */
1454 { 0x0400, 0x45, 0x00 }, /* Ѐ to E */
1455 { 0x0401, 0x45, 0x00 }, /* Ё to E */
1456 { 0x0402, 0x44, 0x00 }, /* Ђ to D */
1457 { 0x0403, 0x47, 0x00 }, /* Ѓ to G */
1458 { 0x0404, 0x45, 0x00 }, /* Є to E */
1459 { 0x0405, 0x5a, 0x00 }, /* Ѕ to Z */
1460 { 0x0406, 0x49, 0x00 }, /* І to I */
1461 { 0x0407, 0x49, 0x00 }, /* Ї to I */
1462 { 0x0408, 0x4a, 0x00 }, /* Ј to J */
1463 { 0x0409, 0x49, 0x00 }, /* Љ to I */
1464 { 0x040A, 0x4e, 0x00 }, /* Њ to N */
1465 { 0x040B, 0x44, 0x00 }, /* Ћ to D */
1466 { 0x040C, 0x4b, 0x00 }, /* Ќ to K */
1467 { 0x040D, 0x49, 0x00 }, /* Ѝ to I */
1468 { 0x040E, 0x55, 0x00 }, /* Ў to U */
1469 { 0x040F, 0x44, 0x00 }, /* Џ to D */
1470 { 0x0410, 0x41, 0x00 }, /* А to A */
1471 { 0x0411, 0x42, 0x00 }, /* Б to B */
1472 { 0x0412, 0x56, 0x00 }, /* В to V */
1473 { 0x0413, 0x47, 0x00 }, /* Г to G */
1474 { 0x0414, 0x44, 0x00 }, /* Д to D */
1475 { 0x0415, 0x45, 0x00 }, /* Е to E */
1476 { 0x0416, 0x5a, 0x68 }, /* Ж to Zh */
1477 { 0x0417, 0x5a, 0x00 }, /* З to Z */
1478 { 0x0418, 0x49, 0x00 }, /* И to I */
1479 { 0x0419, 0x49, 0x00 }, /* Й to I */
1480 { 0x041A, 0x4b, 0x00 }, /* К to K */
1481 { 0x041B, 0x4c, 0x00 }, /* Л to L */
1482 { 0x041C, 0x4d, 0x00 }, /* М to M */
1483 { 0x041D, 0x4e, 0x00 }, /* Н to N */
1484 { 0x041E, 0x4f, 0x00 }, /* О to O */
1485 { 0x041F, 0x50, 0x00 }, /* П to P */
1486 { 0x0420, 0x52, 0x00 }, /* Р to R */
1487 { 0x0421, 0x53, 0x00 }, /* С to S */
1488 { 0x0422, 0x54, 0x00 }, /* Т to T */
1489 { 0x0423, 0x55, 0x00 }, /* У to U */
1490 { 0x0424, 0x46, 0x00 }, /* Ф to F */
1491 { 0x0425, 0x4b, 0x68 }, /* Х to Kh */
1492 { 0x0426, 0x54, 0x63 }, /* Ц to Tc */
1493 { 0x0427, 0x43, 0x68 }, /* Ч to Ch */
1494 { 0x0428, 0x53, 0x68 }, /* Ш to Sh */
1495 { 0x0429, 0x53, 0x68 }, /* Щ to Shch */
1496 { 0x042A, 0x61, 0x00 }, /* to A */
1497 { 0x042B, 0x59, 0x00 }, /* Ы to Y */
1498 { 0x042C, 0x59, 0x00 }, /* to Y */
1499 { 0x042D, 0x45, 0x00 }, /* Э to E */
1500 { 0x042E, 0x49, 0x75 }, /* Ю to Iu */
1501 { 0x042F, 0x49, 0x61 }, /* Я to Ia */
1502 { 0x0430, 0x61, 0x00 }, /* а to a */
1503 { 0x0431, 0x62, 0x00 }, /* б to b */
1504 { 0x0432, 0x76, 0x00 }, /* в to v */
1505 { 0x0433, 0x67, 0x00 }, /* г to g */
1506 { 0x0434, 0x64, 0x00 }, /* д to d */
1507 { 0x0435, 0x65, 0x00 }, /* е to e */
1508 { 0x0436, 0x7a, 0x68 }, /* ж to zh */
1509 { 0x0437, 0x7a, 0x00 }, /* з to z */
1510 { 0x0438, 0x69, 0x00 }, /* и to i */
1511 { 0x0439, 0x69, 0x00 }, /* й to i */
1512 { 0x043A, 0x6b, 0x00 }, /* к to k */
1513 { 0x043B, 0x6c, 0x00 }, /* л to l */
1514 { 0x043C, 0x6d, 0x00 }, /* м to m */
1515 { 0x043D, 0x6e, 0x00 }, /* н to n */
1516 { 0x043E, 0x6f, 0x00 }, /* о to o */
1517 { 0x043F, 0x70, 0x00 }, /* п to p */
1518 { 0x0440, 0x72, 0x00 }, /* р to r */
1519 { 0x0441, 0x73, 0x00 }, /* с to s */
1520 { 0x0442, 0x74, 0x00 }, /* т to t */
1521 { 0x0443, 0x75, 0x00 }, /* у to u */
1522 { 0x0444, 0x66, 0x00 }, /* ф to f */
1523 { 0x0445, 0x6b, 0x68 }, /* х to kh */
1524 { 0x0446, 0x74, 0x63 }, /* ц to tc */
1525 { 0x0447, 0x63, 0x68 }, /* ч to ch */
1526 { 0x0448, 0x73, 0x68 }, /* ш to sh */
1527 { 0x0449, 0x73, 0x68 }, /* щ to shch */
1528 { 0x044A, 0x61, 0x00 }, /* to a */
1529 { 0x044B, 0x79, 0x00 }, /* ы to y */
1530 { 0x044C, 0x79, 0x00 }, /* to y */
1531 { 0x044D, 0x65, 0x00 }, /* э to e */
1532 { 0x044E, 0x69, 0x75 }, /* ю to iu */
1533 { 0x044F, 0x69, 0x61 }, /* я to ia */
1534 { 0x0450, 0x65, 0x00 }, /* ѐ to e */
1535 { 0x0451, 0x65, 0x00 }, /* ё to e */
1536 { 0x0452, 0x64, 0x00 }, /* ђ to d */
1537 { 0x0453, 0x67, 0x00 }, /* ѓ to g */
1538 { 0x0454, 0x65, 0x00 }, /* є to e */
1539 { 0x0455, 0x7a, 0x00 }, /* ѕ to z */
1540 { 0x0456, 0x69, 0x00 }, /* і to i */
1541 { 0x0457, 0x69, 0x00 }, /* ї to i */
1542 { 0x0458, 0x6a, 0x00 }, /* ј to j */
1543 { 0x0459, 0x69, 0x00 }, /* љ to i */
1544 { 0x045A, 0x6e, 0x00 }, /* њ to n */
1545 { 0x045B, 0x64, 0x00 }, /* ћ to d */
1546 { 0x045C, 0x6b, 0x00 }, /* ќ to k */
1547 { 0x045D, 0x69, 0x00 }, /* ѝ to i */
1548 { 0x045E, 0x75, 0x00 }, /* ў to u */
1549 { 0x045F, 0x64, 0x00 }, /* џ to d */
1550 { 0x1E02, 0x42, 0x00 }, /* Ḃ to B */
1551 { 0x1E03, 0x62, 0x00 }, /* ḃ to b */
1552 { 0x1E0A, 0x44, 0x00 }, /* Ḋ to D */
1553 { 0x1E0B, 0x64, 0x00 }, /* ḋ to d */
1554 { 0x1E1E, 0x46, 0x00 }, /* Ḟ to F */
1555 { 0x1E1F, 0x66, 0x00 }, /* ḟ to f */
1556 { 0x1E40, 0x4D, 0x00 }, /* Ṁ to M */
1557 { 0x1E41, 0x6D, 0x00 }, /* ṁ to m */
1558 { 0x1E56, 0x50, 0x00 }, /* Ṗ to P */
1559 { 0x1E57, 0x70, 0x00 }, /* ṗ to p */
1560 { 0x1E60, 0x53, 0x00 }, /* Ṡ to S */
1561 { 0x1E61, 0x73, 0x00 }, /* ṡ to s */
1562 { 0x1E6A, 0x54, 0x00 }, /* Ṫ to T */
1563 { 0x1E6B, 0x74, 0x00 }, /* ṫ to t */
1564 { 0x1E80, 0x57, 0x00 }, /* Ẁ to W */
1565 { 0x1E81, 0x77, 0x00 }, /* ẁ to w */
1566 { 0x1E82, 0x57, 0x00 }, /* Ẃ to W */
1567 { 0x1E83, 0x77, 0x00 }, /* ẃ to w */
1568 { 0x1E84, 0x57, 0x00 }, /* Ẅ to W */
1569 { 0x1E85, 0x77, 0x00 }, /* ẅ to w */
1570 { 0x1EF2, 0x59, 0x00 }, /* Ỳ to Y */
1571 { 0x1EF3, 0x79, 0x00 }, /* ỳ to y */
1572 { 0xFB00, 0x66, 0x66 }, /* ff to ff */
1573 { 0xFB01, 0x66, 0x69 }, /* fi to fi */
1574 { 0xFB02, 0x66, 0x6C }, /* fl to fl */
1575 { 0xFB05, 0x73, 0x74 }, /* ſt to st */
1576 { 0xFB06, 0x73, 0x74 }, /* st to st */
1577 };
1578
1579 /*
1580 ** Convert the input string from UTF-8 into pure ASCII by converting
1581 ** all non-ASCII characters to some combination of characters in the
1582 ** ASCII subset.
1583 **
1584 ** The returned string might contain more characters than the input.
1585 **
1586 ** Space to hold the returned string comes from sqlite3_malloc() and
1587 ** should be freed by the caller.
1588 */
1589 static unsigned char *transliterate(const unsigned char *zIn, int nIn){
1590 unsigned char *zOut = sqlite3_malloc( nIn*4 + 1 );
1591 int c, sz, nOut;
1592 if( zOut==0 ) return 0;
1593 nOut = 0;
1594 while( nIn>0 ){
1595 c = utf8Read(zIn, nIn, &sz);
1596 zIn += sz;
1597 nIn -= sz;
1598 if( c<=127 ){
1599 zOut[nOut++] = c;
1600 }else{
1601 int xTop, xBtm, x;
1602 xTop = sizeof(translit)/sizeof(translit[0]) - 1;
1603 xBtm = 0;
1604 while( xTop>=xBtm ){
1605 x = (xTop + xBtm)/2;
1606 if( translit[x].cFrom==c ){
1607 zOut[nOut++] = translit[x].cTo0;
1608 if( translit[x].cTo1 ){
1609 zOut[nOut++] = translit[x].cTo1;
1610 /* Add an extra "ch" after the "sh" for Щ and щ */
1611 if( c==0x0429 || c== 0x0449 ){
1612 zOut[nOut++] = 'c';
1613 zOut[nOut++] = 'h';
1614 }
1615 }
1616 c = 0;
1617 break;
1618 }else if( translit[x].cFrom>c ){
1619 xTop = x-1;
1620 }else{
1621 xBtm = x+1;
1622 }
1623 }
1624 if( c ) zOut[nOut++] = '?';
1625 }
1626 }
1627 zOut[nOut] = 0;
1628 return zOut;
1629 }
1630
1631 /*
1632 ** Return the number of characters in the shortest prefix of the input
1633 ** string that transliterates to an ASCII string nTrans bytes or longer.
1634 ** Or, if the transliteration of the input string is less than nTrans
1635 ** bytes in size, return the number of characters in the input string.
1636 */
1637 static int translen_to_charlen(const char *zIn, int nIn, int nTrans){
1638 int i, c, sz, nOut;
1639 int nChar;
1640
1641 i = nOut = 0;
1642 for(nChar=0; i<nIn && nOut<nTrans; nChar++){
1643 c = utf8Read((const unsigned char *)&zIn[i], nIn-i, &sz);
1644 i += sz;
1645
1646 nOut++;
1647 if( c>=128 ){
1648 int xTop, xBtm, x;
1649 xTop = sizeof(translit)/sizeof(translit[0]) - 1;
1650 xBtm = 0;
1651 while( xTop>=xBtm ){
1652 x = (xTop + xBtm)/2;
1653 if( translit[x].cFrom==c ){
1654 if( translit[x].cTo1 ) nOut++;
1655 if( c==0x0429 || c== 0x0449 ) nOut += 2;
1656 break;
1657 }else if( translit[x].cFrom>c ){
1658 xTop = x-1;
1659 }else{
1660 xBtm = x+1;
1661 }
1662 }
1663 }
1664 }
1665
1666 return nChar;
1667 }
1668
1669
1670 /*
1671 ** spellfix1_translit(X)
1672 **
1673 ** Convert a string that contains non-ASCII Roman characters into
1674 ** pure ASCII.
1675 */
1676 static void transliterateSqlFunc(
1677 sqlite3_context *context,
1678 int argc,
1679 sqlite3_value **argv
1680 ){
1681 const unsigned char *zIn = sqlite3_value_text(argv[0]);
1682 int nIn = sqlite3_value_bytes(argv[0]);
1683 unsigned char *zOut = transliterate(zIn, nIn);
1684 if( zOut==0 ){
1685 sqlite3_result_error_nomem(context);
1686 }else{
1687 sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free);
1688 }
1689 }
1690
1691 /*
1692 ** spellfix1_scriptcode(X)
1693 **
1694 ** Try to determine the dominant script used by the word X and return
1695 ** its ISO 15924 numeric code.
1696 **
1697 ** The current implementation only understands the following scripts:
1698 **
1699 ** 215 (Latin)
1700 ** 220 (Cyrillic)
1701 ** 200 (Greek)
1702 **
1703 ** This routine will return 998 if the input X contains characters from
1704 ** two or more of the above scripts or 999 if X contains no characters
1705 ** from any of the above scripts.
1706 */
1707 static void scriptCodeSqlFunc(
1708 sqlite3_context *context,
1709 int argc,
1710 sqlite3_value **argv
1711 ){
1712 const unsigned char *zIn = sqlite3_value_text(argv[0]);
1713 int nIn = sqlite3_value_bytes(argv[0]);
1714 int c, sz;
1715 int scriptMask = 0;
1716 int res;
1717 # define SCRIPT_LATIN 0x0001
1718 # define SCRIPT_CYRILLIC 0x0002
1719 # define SCRIPT_GREEK 0x0004
1720
1721 while( nIn>0 ){
1722 c = utf8Read(zIn, nIn, &sz);
1723 zIn += sz;
1724 nIn -= sz;
1725 if( c<0x02af ){
1726 scriptMask |= SCRIPT_LATIN;
1727 }else if( c>=0x0400 && c<=0x04ff ){
1728 scriptMask |= SCRIPT_CYRILLIC;
1729 }else if( c>=0x0386 && c<=0x03ce ){
1730 scriptMask |= SCRIPT_GREEK;
1731 }
1732 }
1733 switch( scriptMask ){
1734 case 0: res = 999; break;
1735 case SCRIPT_LATIN: res = 215; break;
1736 case SCRIPT_CYRILLIC: res = 220; break;
1737 case SCRIPT_GREEK: res = 200; break;
1738 default: res = 998; break;
1739 }
1740 sqlite3_result_int(context, res);
1741 }
1742
1743 /* End transliterate
1744 ******************************************************************************
1745 ******************************************************************************
1746 ** Begin spellfix1 virtual table.
1747 */
1748
1749 /* Maximum length of a phonehash used for querying the shadow table */
1750 #define SPELLFIX_MX_HASH 8
1751
1752 /* Maximum number of hash strings to examine per query */
1753 #define SPELLFIX_MX_RUN 1
1754
1755 typedef struct spellfix1_vtab spellfix1_vtab;
1756 typedef struct spellfix1_cursor spellfix1_cursor;
1757
1758 /* Fuzzy-search virtual table object */
1759 struct spellfix1_vtab {
1760 sqlite3_vtab base; /* Base class - must be first */
1761 sqlite3 *db; /* Database connection */
1762 char *zDbName; /* Name of database holding this table */
1763 char *zTableName; /* Name of the virtual table */
1764 char *zCostTable; /* Table holding edit-distance cost numbers */
1765 EditDist3Config *pConfig3; /* Parsed edit distance costs */
1766 };
1767
1768 /* Fuzzy-search cursor object */
1769 struct spellfix1_cursor {
1770 sqlite3_vtab_cursor base; /* Base class - must be first */
1771 spellfix1_vtab *pVTab; /* The table to which this cursor belongs */
1772 char *zPattern; /* rhs of MATCH clause */
1773 int nRow; /* Number of rows of content */
1774 int nAlloc; /* Number of allocated rows */
1775 int iRow; /* Current row of content */
1776 int iLang; /* Value of the langid= constraint */
1777 int iTop; /* Value of the top= constraint */
1778 int iScope; /* Value of the scope= constraint */
1779 int nSearch; /* Number of vocabulary items checked */
1780 sqlite3_stmt *pFullScan; /* Shadow query for a full table scan */
1781 struct spellfix1_row { /* For each row of content */
1782 sqlite3_int64 iRowid; /* Rowid for this row */
1783 char *zWord; /* Text for this row */
1784 int iRank; /* Rank for this row */
1785 int iDistance; /* Distance from pattern for this row */
1786 int iScore; /* Score for sorting */
1787 int iMatchlen; /* Value of matchlen column (or -1) */
1788 char zHash[SPELLFIX_MX_HASH]; /* the phonehash used for this match */
1789 } *a;
1790 };
1791
1792 /*
1793 ** Construct one or more SQL statements from the format string given
1794 ** and then evaluate those statements. The success code is written
1795 ** into *pRc.
1796 **
1797 ** If *pRc is initially non-zero then this routine is a no-op.
1798 */
1799 static void spellfix1DbExec(
1800 int *pRc, /* Success code */
1801 sqlite3 *db, /* Database in which to run SQL */
1802 const char *zFormat, /* Format string for SQL */
1803 ... /* Arguments to the format string */
1804 ){
1805 va_list ap;
1806 char *zSql;
1807 if( *pRc ) return;
1808 va_start(ap, zFormat);
1809 zSql = sqlite3_vmprintf(zFormat, ap);
1810 va_end(ap);
1811 if( zSql==0 ){
1812 *pRc = SQLITE_NOMEM;
1813 }else{
1814 *pRc = sqlite3_exec(db, zSql, 0, 0, 0);
1815 sqlite3_free(zSql);
1816 }
1817 }
1818
1819 /*
1820 ** xDisconnect/xDestroy method for the fuzzy-search module.
1821 */
1822 static int spellfix1Uninit(int isDestroy, sqlite3_vtab *pVTab){
1823 spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
1824 int rc = SQLITE_OK;
1825 if( isDestroy ){
1826 sqlite3 *db = p->db;
1827 spellfix1DbExec(&rc, db, "DROP TABLE IF EXISTS \"%w\".\"%w_vocab\"",
1828 p->zDbName, p->zTableName);
1829 }
1830 if( rc==SQLITE_OK ){
1831 sqlite3_free(p->zTableName);
1832 editDist3ConfigDelete(p->pConfig3);
1833 sqlite3_free(p->zCostTable);
1834 sqlite3_free(p);
1835 }
1836 return rc;
1837 }
1838 static int spellfix1Disconnect(sqlite3_vtab *pVTab){
1839 return spellfix1Uninit(0, pVTab);
1840 }
1841 static int spellfix1Destroy(sqlite3_vtab *pVTab){
1842 return spellfix1Uninit(1, pVTab);
1843 }
1844
1845 /*
1846 ** Make a copy of a string. Remove leading and trailing whitespace
1847 ** and dequote it.
1848 */
1849 static char *spellfix1Dequote(const char *zIn){
1850 char *zOut;
1851 int i, j;
1852 char c;
1853 while( isspace(zIn[0]) ) zIn++;
1854 zOut = sqlite3_mprintf("%s", zIn);
1855 if( zOut==0 ) return 0;
1856 i = (int)strlen(zOut);
1857 #if 0 /* The parser will never leave spaces at the end */
1858 while( i>0 && isspace(zOut[i-1]) ){ i--; }
1859 #endif
1860 zOut[i] = 0;
1861 c = zOut[0];
1862 if( c=='\'' || c=='"' ){
1863 for(i=1, j=0; ALWAYS(zOut[i]); i++){
1864 zOut[j++] = zOut[i];
1865 if( zOut[i]==c ){
1866 if( zOut[i+1]==c ){
1867 i++;
1868 }else{
1869 zOut[j-1] = 0;
1870 break;
1871 }
1872 }
1873 }
1874 }
1875 return zOut;
1876 }
1877
1878
1879 /*
1880 ** xConnect/xCreate method for the spellfix1 module. Arguments are:
1881 **
1882 ** argv[0] -> module name ("spellfix1")
1883 ** argv[1] -> database name
1884 ** argv[2] -> table name
1885 ** argv[3].. -> optional arguments (i.e. "edit_cost_table" parameter)
1886 */
1887 static int spellfix1Init(
1888 int isCreate,
1889 sqlite3 *db,
1890 void *pAux,
1891 int argc, const char *const*argv,
1892 sqlite3_vtab **ppVTab,
1893 char **pzErr
1894 ){
1895 spellfix1_vtab *pNew = 0;
1896 /* const char *zModule = argv[0]; // not used */
1897 const char *zDbName = argv[1];
1898 const char *zTableName = argv[2];
1899 int nDbName;
1900 int rc = SQLITE_OK;
1901 int i;
1902
1903 nDbName = (int)strlen(zDbName);
1904 pNew = sqlite3_malloc( sizeof(*pNew) + nDbName + 1);
1905 if( pNew==0 ){
1906 rc = SQLITE_NOMEM;
1907 }else{
1908 memset(pNew, 0, sizeof(*pNew));
1909 pNew->zDbName = (char*)&pNew[1];
1910 memcpy(pNew->zDbName, zDbName, nDbName+1);
1911 pNew->zTableName = sqlite3_mprintf("%s", zTableName);
1912 pNew->db = db;
1913 if( pNew->zTableName==0 ){
1914 rc = SQLITE_NOMEM;
1915 }else{
1916 rc = sqlite3_declare_vtab(db,
1917 "CREATE TABLE x(word,rank,distance,langid, "
1918 "score, matchlen, phonehash HIDDEN, "
1919 "top HIDDEN, scope HIDDEN, srchcnt HIDDEN, "
1920 "soundslike HIDDEN, command HIDDEN)"
1921 );
1922 #define SPELLFIX_COL_WORD 0
1923 #define SPELLFIX_COL_RANK 1
1924 #define SPELLFIX_COL_DISTANCE 2
1925 #define SPELLFIX_COL_LANGID 3
1926 #define SPELLFIX_COL_SCORE 4
1927 #define SPELLFIX_COL_MATCHLEN 5
1928 #define SPELLFIX_COL_PHONEHASH 6
1929 #define SPELLFIX_COL_TOP 7
1930 #define SPELLFIX_COL_SCOPE 8
1931 #define SPELLFIX_COL_SRCHCNT 9
1932 #define SPELLFIX_COL_SOUNDSLIKE 10
1933 #define SPELLFIX_COL_COMMAND 11
1934 }
1935 if( rc==SQLITE_OK && isCreate ){
1936 spellfix1DbExec(&rc, db,
1937 "CREATE TABLE IF NOT EXISTS \"%w\".\"%w_vocab\"(\n"
1938 " id INTEGER PRIMARY KEY,\n"
1939 " rank INT,\n"
1940 " langid INT,\n"
1941 " word TEXT,\n"
1942 " k1 TEXT,\n"
1943 " k2 TEXT\n"
1944 ");\n",
1945 zDbName, zTableName
1946 );
1947 spellfix1DbExec(&rc, db,
1948 "CREATE INDEX IF NOT EXISTS \"%w\".\"%w_vocab_index_langid_k2\" "
1949 "ON \"%w_vocab\"(langid,k2);",
1950 zDbName, zTableName, zTableName
1951 );
1952 }
1953 for(i=3; rc==SQLITE_OK && i<argc; i++){
1954 if( strncmp(argv[i],"edit_cost_table=",16)==0 && pNew->zCostTable==0 ){
1955 pNew->zCostTable = spellfix1Dequote(&argv[i][16]);
1956 if( pNew->zCostTable==0 ) rc = SQLITE_NOMEM;
1957 continue;
1958 }
1959 *pzErr = sqlite3_mprintf("bad argument to spellfix1(): \"%s\"", argv[i]);
1960 rc = SQLITE_ERROR;
1961 }
1962 }
1963
1964 if( rc && pNew ){
1965 *ppVTab = 0;
1966 spellfix1Uninit(0, &pNew->base);
1967 }else{
1968 *ppVTab = (sqlite3_vtab *)pNew;
1969 }
1970 return rc;
1971 }
1972
1973 /*
1974 ** The xConnect and xCreate methods
1975 */
1976 static int spellfix1Connect(
1977 sqlite3 *db,
1978 void *pAux,
1979 int argc, const char *const*argv,
1980 sqlite3_vtab **ppVTab,
1981 char **pzErr
1982 ){
1983 return spellfix1Init(0, db, pAux, argc, argv, ppVTab, pzErr);
1984 }
1985 static int spellfix1Create(
1986 sqlite3 *db,
1987 void *pAux,
1988 int argc, const char *const*argv,
1989 sqlite3_vtab **ppVTab,
1990 char **pzErr
1991 ){
1992 return spellfix1Init(1, db, pAux, argc, argv, ppVTab, pzErr);
1993 }
1994
1995 /*
1996 ** Clear all of the content from a cursor.
1997 */
1998 static void spellfix1ResetCursor(spellfix1_cursor *pCur){
1999 int i;
2000 for(i=0; i<pCur->nRow; i++){
2001 sqlite3_free(pCur->a[i].zWord);
2002 }
2003 pCur->nRow = 0;
2004 pCur->iRow = 0;
2005 pCur->nSearch = 0;
2006 if( pCur->pFullScan ){
2007 sqlite3_finalize(pCur->pFullScan);
2008 pCur->pFullScan = 0;
2009 }
2010 }
2011
2012 /*
2013 ** Resize the cursor to hold up to N rows of content
2014 */
2015 static void spellfix1ResizeCursor(spellfix1_cursor *pCur, int N){
2016 struct spellfix1_row *aNew;
2017 assert( N>=pCur->nRow );
2018 aNew = sqlite3_realloc(pCur->a, sizeof(pCur->a[0])*N);
2019 if( aNew==0 && N>0 ){
2020 spellfix1ResetCursor(pCur);
2021 sqlite3_free(pCur->a);
2022 pCur->nAlloc = 0;
2023 pCur->a = 0;
2024 }else{
2025 pCur->nAlloc = N;
2026 pCur->a = aNew;
2027 }
2028 }
2029
2030
2031 /*
2032 ** Close a fuzzy-search cursor.
2033 */
2034 static int spellfix1Close(sqlite3_vtab_cursor *cur){
2035 spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
2036 spellfix1ResetCursor(pCur);
2037 spellfix1ResizeCursor(pCur, 0);
2038 sqlite3_free(pCur->zPattern);
2039 sqlite3_free(pCur);
2040 return SQLITE_OK;
2041 }
2042
2043 /*
2044 ** Search for terms of these forms:
2045 **
2046 ** (A) word MATCH $str
2047 ** (B) langid == $langid
2048 ** (C) top = $top
2049 ** (D) scope = $scope
2050 ** (E) distance < $distance
2051 ** (F) distance <= $distance
2052 ** (G) rowid = $rowid
2053 **
2054 ** The plan number is a bit mask formed with these bits:
2055 **
2056 ** 0x01 (A) is found
2057 ** 0x02 (B) is found
2058 ** 0x04 (C) is found
2059 ** 0x08 (D) is found
2060 ** 0x10 (E) is found
2061 ** 0x20 (F) is found
2062 ** 0x40 (G) is found
2063 **
2064 ** filter.argv[*] values contains $str, $langid, $top, $scope and $rowid
2065 ** if specified and in that order.
2066 */
2067 static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
2068 int iPlan = 0;
2069 int iLangTerm = -1;
2070 int iTopTerm = -1;
2071 int iScopeTerm = -1;
2072 int iDistTerm = -1;
2073 int iRowidTerm = -1;
2074 int i;
2075 const struct sqlite3_index_constraint *pConstraint;
2076 pConstraint = pIdxInfo->aConstraint;
2077 for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
2078 if( pConstraint->usable==0 ) continue;
2079
2080 /* Terms of the form: word MATCH $str */
2081 if( (iPlan & 1)==0
2082 && pConstraint->iColumn==SPELLFIX_COL_WORD
2083 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH
2084 ){
2085 iPlan |= 1;
2086 pIdxInfo->aConstraintUsage[i].argvIndex = 1;
2087 pIdxInfo->aConstraintUsage[i].omit = 1;
2088 }
2089
2090 /* Terms of the form: langid = $langid */
2091 if( (iPlan & 2)==0
2092 && pConstraint->iColumn==SPELLFIX_COL_LANGID
2093 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
2094 ){
2095 iPlan |= 2;
2096 iLangTerm = i;
2097 }
2098
2099 /* Terms of the form: top = $top */
2100 if( (iPlan & 4)==0
2101 && pConstraint->iColumn==SPELLFIX_COL_TOP
2102 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
2103 ){
2104 iPlan |= 4;
2105 iTopTerm = i;
2106 }
2107
2108 /* Terms of the form: scope = $scope */
2109 if( (iPlan & 8)==0
2110 && pConstraint->iColumn==SPELLFIX_COL_SCOPE
2111 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
2112 ){
2113 iPlan |= 8;
2114 iScopeTerm = i;
2115 }
2116
2117 /* Terms of the form: distance < $dist or distance <= $dist */
2118 if( (iPlan & (16|32))==0
2119 && pConstraint->iColumn==SPELLFIX_COL_DISTANCE
2120 && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
2121 || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
2122 ){
2123 iPlan |= pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ? 16 : 32;
2124 iDistTerm = i;
2125 }
2126
2127 /* Terms of the form: distance < $dist or distance <= $dist */
2128 if( (iPlan & 64)==0
2129 && pConstraint->iColumn<0
2130 && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
2131 ){
2132 iPlan |= 64;
2133 iRowidTerm = i;
2134 }
2135 }
2136 if( iPlan&1 ){
2137 int idx = 2;
2138 pIdxInfo->idxNum = iPlan;
2139 if( pIdxInfo->nOrderBy==1
2140 && pIdxInfo->aOrderBy[0].iColumn==SPELLFIX_COL_SCORE
2141 && pIdxInfo->aOrderBy[0].desc==0
2142 ){
2143 pIdxInfo->orderByConsumed = 1; /* Default order by iScore */
2144 }
2145 if( iPlan&2 ){
2146 pIdxInfo->aConstraintUsage[iLangTerm].argvIndex = idx++;
2147 pIdxInfo->aConstraintUsage[iLangTerm].omit = 1;
2148 }
2149 if( iPlan&4 ){
2150 pIdxInfo->aConstraintUsage[iTopTerm].argvIndex = idx++;
2151 pIdxInfo->aConstraintUsage[iTopTerm].omit = 1;
2152 }
2153 if( iPlan&8 ){
2154 pIdxInfo->aConstraintUsage[iScopeTerm].argvIndex = idx++;
2155 pIdxInfo->aConstraintUsage[iScopeTerm].omit = 1;
2156 }
2157 if( iPlan&(16|32) ){
2158 pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = idx++;
2159 pIdxInfo->aConstraintUsage[iDistTerm].omit = 1;
2160 }
2161 pIdxInfo->estimatedCost = 1e5;
2162 }else if( (iPlan & 64) ){
2163 pIdxInfo->idxNum = 64;
2164 pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
2165 pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
2166 pIdxInfo->estimatedCost = 5;
2167 }else{
2168 pIdxInfo->idxNum = 0;
2169 pIdxInfo->estimatedCost = 1e50;
2170 }
2171 return SQLITE_OK;
2172 }
2173
2174 /*
2175 ** Open a new fuzzy-search cursor.
2176 */
2177 static int spellfix1Open(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
2178 spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
2179 spellfix1_cursor *pCur;
2180 pCur = sqlite3_malloc( sizeof(*pCur) );
2181 if( pCur==0 ) return SQLITE_NOMEM;
2182 memset(pCur, 0, sizeof(*pCur));
2183 pCur->pVTab = p;
2184 *ppCursor = &pCur->base;
2185 return SQLITE_OK;
2186 }
2187
2188 /*
2189 ** Adjust a distance measurement by the words rank in order to show
2190 ** preference to common words.
2191 */
2192 static int spellfix1Score(int iDistance, int iRank){
2193 int iLog2;
2194 for(iLog2=0; iRank>0; iLog2++, iRank>>=1){}
2195 return iDistance + 32 - iLog2;
2196 }
2197
2198 /*
2199 ** Compare two spellfix1_row objects for sorting purposes in qsort() such
2200 ** that they sort in order of increasing distance.
2201 */
2202 static int spellfix1RowCompare(const void *A, const void *B){
2203 const struct spellfix1_row *a = (const struct spellfix1_row*)A;
2204 const struct spellfix1_row *b = (const struct spellfix1_row*)B;
2205 return a->iScore - b->iScore;
2206 }
2207
2208 /*
2209 ** A structure used to pass information from spellfix1FilterForMatch()
2210 ** into spellfix1RunQuery().
2211 */
2212 typedef struct MatchQuery {
2213 spellfix1_cursor *pCur; /* The cursor being queried */
2214 sqlite3_stmt *pStmt; /* shadow table query statment */
2215 char zHash[SPELLFIX_MX_HASH]; /* The current phonehash for zPattern */
2216 const char *zPattern; /* Transliterated input string */
2217 int nPattern; /* Length of zPattern */
2218 EditDist3FromString *pMatchStr3; /* Original unicode string */
2219 EditDist3Config *pConfig3; /* Edit-distance cost coefficients */
2220 const EditDist3Lang *pLang; /* The selected language coefficients */
2221 int iLang; /* The language id */
2222 int iScope; /* Default scope */
2223 int iMaxDist; /* Maximum allowed edit distance, or -1 */
2224 int rc; /* Error code */
2225 int nRun; /* Number of prior runs for the same zPattern */
2226 char azPrior[SPELLFIX_MX_RUN][SPELLFIX_MX_HASH]; /* Prior hashes */
2227 } MatchQuery;
2228
2229 /*
2230 ** Run a query looking for the best matches against zPattern using
2231 ** zHash as the character class seed hash.
2232 */
2233 static void spellfix1RunQuery(MatchQuery *p, const char *zQuery, int nQuery){
2234 const char *zK1;
2235 const char *zWord;
2236 int iDist;
2237 int iRank;
2238 int iScore;
2239 int iWorst = 0;
2240 int idx;
2241 int idxWorst = -1;
2242 int i;
2243 int iScope = p->iScope;
2244 spellfix1_cursor *pCur = p->pCur;
2245 sqlite3_stmt *pStmt = p->pStmt;
2246 char zHash1[SPELLFIX_MX_HASH];
2247 char zHash2[SPELLFIX_MX_HASH];
2248 char *zClass;
2249 int nClass;
2250 int rc;
2251
2252 if( pCur->a==0 || p->rc ) return; /* Prior memory allocation failure */
2253 zClass = (char*)phoneticHash((unsigned char*)zQuery, nQuery);
2254 if( zClass==0 ){
2255 p->rc = SQLITE_NOMEM;
2256 return;
2257 }
2258 nClass = (int)strlen(zClass);
2259 if( nClass>SPELLFIX_MX_HASH-2 ){
2260 nClass = SPELLFIX_MX_HASH-2;
2261 zClass[nClass] = 0;
2262 }
2263 if( nClass<=iScope ){
2264 if( nClass>2 ){
2265 iScope = nClass-1;
2266 }else{
2267 iScope = nClass;
2268 }
2269 }
2270 memcpy(zHash1, zClass, iScope);
2271 sqlite3_free(zClass);
2272 zHash1[iScope] = 0;
2273 memcpy(zHash2, zHash1, iScope);
2274 zHash2[iScope] = 'Z';
2275 zHash2[iScope+1] = 0;
2276 #if SPELLFIX_MX_RUN>1
2277 for(i=0; i<p->nRun; i++){
2278 if( strcmp(p->azPrior[i], zHash1)==0 ) return;
2279 }
2280 #endif
2281 assert( p->nRun<SPELLFIX_MX_RUN );
2282 memcpy(p->azPrior[p->nRun++], zHash1, iScope+1);
2283 if( sqlite3_bind_text(pStmt, 1, zHash1, -1, SQLITE_STATIC)==SQLITE_NOMEM
2284 || sqlite3_bind_text(pStmt, 2, zHash2, -1, SQLITE_STATIC)==SQLITE_NOMEM
2285 ){
2286 p->rc = SQLITE_NOMEM;
2287 return;
2288 }
2289 #if SPELLFIX_MX_RUN>1
2290 for(i=0; i<pCur->nRow; i++){
2291 if( pCur->a[i].iScore>iWorst ){
2292 iWorst = pCur->a[i].iScore;
2293 idxWorst = i;
2294 }
2295 }
2296 #endif
2297 while( sqlite3_step(pStmt)==SQLITE_ROW ){
2298 int iMatchlen = -1;
2299 iRank = sqlite3_column_int(pStmt, 2);
2300 if( p->pMatchStr3 ){
2301 int nWord = sqlite3_column_bytes(pStmt, 1);
2302 zWord = (const char*)sqlite3_column_text(pStmt, 1);
2303 iDist = editDist3Core(p->pMatchStr3, zWord, nWord, p->pLang, &iMatchlen);
2304 }else{
2305 zK1 = (const char*)sqlite3_column_text(pStmt, 3);
2306 if( zK1==0 ) continue;
2307 iDist = editdist1(p->zPattern, zK1, 0);
2308 }
2309 if( iDist<0 ){
2310 p->rc = SQLITE_NOMEM;
2311 break;
2312 }
2313 pCur->nSearch++;
2314 iScore = spellfix1Score(iDist,iRank);
2315 if( p->iMaxDist>=0 ){
2316 if( iDist>p->iMaxDist ) continue;
2317 if( pCur->nRow>=pCur->nAlloc-1 ){
2318 spellfix1ResizeCursor(pCur, pCur->nAlloc*2 + 10);
2319 if( pCur->a==0 ) break;
2320 }
2321 idx = pCur->nRow;
2322 }else if( pCur->nRow<pCur->nAlloc ){
2323 idx = pCur->nRow;
2324 }else if( iScore<iWorst ){
2325 idx = idxWorst;
2326 sqlite3_free(pCur->a[idx].zWord);
2327 }else{
2328 continue;
2329 }
2330 pCur->a[idx].zWord = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 1));
2331 if( pCur->a[idx].zWord==0 ){
2332 p->rc = SQLITE_NOMEM;
2333 break;
2334 }
2335 pCur->a[idx].iRowid = sqlite3_column_int64(pStmt, 0);
2336 pCur->a[idx].iRank = iRank;
2337 pCur->a[idx].iDistance = iDist;
2338 pCur->a[idx].iScore = iScore;
2339 pCur->a[idx].iMatchlen = iMatchlen;
2340 memcpy(pCur->a[idx].zHash, zHash1, iScope+1);
2341 if( pCur->nRow<pCur->nAlloc ) pCur->nRow++;
2342 if( pCur->nRow==pCur->nAlloc ){
2343 iWorst = pCur->a[0].iScore;
2344 idxWorst = 0;
2345 for(i=1; i<pCur->nRow; i++){
2346 iScore = pCur->a[i].iScore;
2347 if( iWorst<iScore ){
2348 iWorst = iScore;
2349 idxWorst = i;
2350 }
2351 }
2352 }
2353 }
2354 rc = sqlite3_reset(pStmt);
2355 if( rc ) p->rc = rc;
2356 }
2357
2358 /*
2359 ** This version of the xFilter method work if the MATCH term is present
2360 ** and we are doing a scan.
2361 */
2362 static int spellfix1FilterForMatch(
2363 spellfix1_cursor *pCur,
2364 int idxNum,
2365 int argc,
2366 sqlite3_value **argv
2367 ){
2368 const unsigned char *zMatchThis; /* RHS of the MATCH operator */
2369 EditDist3FromString *pMatchStr3 = 0; /* zMatchThis as an editdist string */
2370 char *zPattern; /* Transliteration of zMatchThis */
2371 int nPattern; /* Length of zPattern */
2372 int iLimit = 20; /* Max number of rows of output */
2373 int iScope = 3; /* Use this many characters of zClass */
2374 int iLang = 0; /* Language code */
2375 char *zSql; /* SQL of shadow table query */
2376 sqlite3_stmt *pStmt = 0; /* Shadow table query */
2377 int rc; /* Result code */
2378 int idx = 1; /* Next available filter parameter */
2379 spellfix1_vtab *p = pCur->pVTab; /* The virtual table that owns pCur */
2380 MatchQuery x; /* For passing info to RunQuery() */
2381
2382 /* Load the cost table if we have not already done so */
2383 if( p->zCostTable!=0 && p->pConfig3==0 ){
2384 p->pConfig3 = sqlite3_malloc( sizeof(p->pConfig3[0]) );
2385 if( p->pConfig3==0 ) return SQLITE_NOMEM;
2386 memset(p->pConfig3, 0, sizeof(p->pConfig3[0]));
2387 rc = editDist3ConfigLoad(p->pConfig3, p->db, p->zCostTable);
2388 if( rc ) return rc;
2389 }
2390 memset(&x, 0, sizeof(x));
2391 x.iScope = 3; /* Default scope if none specified by "WHERE scope=N" */
2392 x.iMaxDist = -1; /* Maximum allowed edit distance */
2393
2394 if( idxNum&2 ){
2395 iLang = sqlite3_value_int(argv[idx++]);
2396 }
2397 if( idxNum&4 ){
2398 iLimit = sqlite3_value_int(argv[idx++]);
2399 if( iLimit<1 ) iLimit = 1;
2400 }
2401 if( idxNum&8 ){
2402 x.iScope = sqlite3_value_int(argv[idx++]);
2403 if( x.iScope<1 ) x.iScope = 1;
2404 if( x.iScope>SPELLFIX_MX_HASH-2 ) x.iScope = SPELLFIX_MX_HASH-2;
2405 }
2406 if( idxNum&(16|32) ){
2407 x.iMaxDist = sqlite3_value_int(argv[idx++]);
2408 if( idxNum&16 ) x.iMaxDist--;
2409 if( x.iMaxDist<0 ) x.iMaxDist = 0;
2410 }
2411 spellfix1ResetCursor(pCur);
2412 spellfix1ResizeCursor(pCur, iLimit);
2413 zMatchThis = sqlite3_value_text(argv[0]);
2414 if( zMatchThis==0 ) return SQLITE_OK;
2415 if( p->pConfig3 ){
2416 x.pLang = editDist3FindLang(p->pConfig3, iLang);
2417 pMatchStr3 = editDist3FromStringNew(x.pLang, (const char*)zMatchThis, -1);
2418 if( pMatchStr3==0 ){
2419 x.rc = SQLITE_NOMEM;
2420 goto filter_exit;
2421 }
2422 }else{
2423 x.pLang = 0;
2424 }
2425 zPattern = (char*)transliterate(zMatchThis, sqlite3_value_bytes(argv[0]));
2426 sqlite3_free(pCur->zPattern);
2427 pCur->zPattern = zPattern;
2428 if( zPattern==0 ){
2429 x.rc = SQLITE_NOMEM;
2430 goto filter_exit;
2431 }
2432 nPattern = (int)strlen(zPattern);
2433 if( zPattern[nPattern-1]=='*' ) nPattern--;
2434 zSql = sqlite3_mprintf(
2435 "SELECT id, word, rank, k1"
2436 " FROM \"%w\".\"%w_vocab\""
2437 " WHERE langid=%d AND k2>=?1 AND k2<?2",
2438 p->zDbName, p->zTableName, iLang
2439 );
2440 if( zSql==0 ){
2441 x.rc = SQLITE_NOMEM;
2442 pStmt = 0;
2443 goto filter_exit;
2444 }
2445 rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
2446 sqlite3_free(zSql);
2447 pCur->iLang = iLang;
2448 x.pCur = pCur;
2449 x.pStmt = pStmt;
2450 x.zPattern = zPattern;
2451 x.nPattern = nPattern;
2452 x.pMatchStr3 = pMatchStr3;
2453 x.iLang = iLang;
2454 x.rc = rc;
2455 x.pConfig3 = p->pConfig3;
2456 if( x.rc==SQLITE_OK ){
2457 spellfix1RunQuery(&x, zPattern, nPattern);
2458 }
2459
2460 if( pCur->a ){
2461 qsort(pCur->a, pCur->nRow, sizeof(pCur->a[0]), spellfix1RowCompare);
2462 pCur->iTop = iLimit;
2463 pCur->iScope = iScope;
2464 }else{
2465 x.rc = SQLITE_NOMEM;
2466 }
2467
2468 filter_exit:
2469 sqlite3_finalize(pStmt);
2470 editDist3FromStringDelete(pMatchStr3);
2471 return x.rc;
2472 }
2473
2474 /*
2475 ** This version of xFilter handles a full-table scan case
2476 */
2477 static int spellfix1FilterForFullScan(
2478 spellfix1_cursor *pCur,
2479 int idxNum,
2480 int argc,
2481 sqlite3_value **argv
2482 ){
2483 int rc = SQLITE_OK;
2484 char *zSql;
2485 spellfix1_vtab *pVTab = pCur->pVTab;
2486 spellfix1ResetCursor(pCur);
2487 assert( idxNum==0 || idxNum==64 );
2488 zSql = sqlite3_mprintf(
2489 "SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"%s",
2490 pVTab->zDbName, pVTab->zTableName,
2491 ((idxNum & 64) ? " WHERE rowid=?" : "")
2492 );
2493 if( zSql==0 ) return SQLITE_NOMEM;
2494 rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pFullScan, 0);
2495 sqlite3_free(zSql);
2496 if( rc==SQLITE_OK && (idxNum & 64) ){
2497 assert( argc==1 );
2498 rc = sqlite3_bind_value(pCur->pFullScan, 1, argv[0]);
2499 }
2500 pCur->nRow = pCur->iRow = 0;
2501 if( rc==SQLITE_OK ){
2502 rc = sqlite3_step(pCur->pFullScan);
2503 if( rc==SQLITE_ROW ){ pCur->iRow = -1; rc = SQLITE_OK; }
2504 if( rc==SQLITE_DONE ){ rc = SQLITE_OK; }
2505 }else{
2506 pCur->iRow = 0;
2507 }
2508 return rc;
2509 }
2510
2511
2512 /*
2513 ** Called to "rewind" a cursor back to the beginning so that
2514 ** it starts its output over again. Always called at least once
2515 ** prior to any spellfix1Column, spellfix1Rowid, or spellfix1Eof call.
2516 */
2517 static int spellfix1Filter(
2518 sqlite3_vtab_cursor *cur,
2519 int idxNum, const char *idxStr,
2520 int argc, sqlite3_value **argv
2521 ){
2522 spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
2523 int rc;
2524 if( idxNum & 1 ){
2525 rc = spellfix1FilterForMatch(pCur, idxNum, argc, argv);
2526 }else{
2527 rc = spellfix1FilterForFullScan(pCur, idxNum, argc, argv);
2528 }
2529 return rc;
2530 }
2531
2532
2533 /*
2534 ** Advance a cursor to its next row of output
2535 */
2536 static int spellfix1Next(sqlite3_vtab_cursor *cur){
2537 spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
2538 int rc = SQLITE_OK;
2539 if( pCur->iRow < pCur->nRow ){
2540 if( pCur->pFullScan ){
2541 rc = sqlite3_step(pCur->pFullScan);
2542 if( rc!=SQLITE_ROW ) pCur->iRow = pCur->nRow;
2543 if( rc==SQLITE_ROW || rc==SQLITE_DONE ) rc = SQLITE_OK;
2544 }else{
2545 pCur->iRow++;
2546 }
2547 }
2548 return rc;
2549 }
2550
2551 /*
2552 ** Return TRUE if we are at the end-of-file
2553 */
2554 static int spellfix1Eof(sqlite3_vtab_cursor *cur){
2555 spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
2556 return pCur->iRow>=pCur->nRow;
2557 }
2558
2559 /*
2560 ** Return columns from the current row.
2561 */
2562 static int spellfix1Column(
2563 sqlite3_vtab_cursor *cur,
2564 sqlite3_context *ctx,
2565 int i
2566 ){
2567 spellfix1_cursor *pCur = (spellfix1_cursor*)cur;
2568 if( pCur->pFullScan ){
2569 if( i<=SPELLFIX_COL_LANGID ){
2570 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pFullScan, i));
2571 }else{
2572 sqlite3_result_null(ctx);
2573 }
2574 return SQLITE_OK;
2575 }
2576 switch( i ){
2577 case SPELLFIX_COL_WORD: {
2578 sqlite3_result_text(ctx, pCur->a[pCur->iRow].zWord, -1, SQLITE_STATIC);
2579 break;
2580 }
2581 case SPELLFIX_COL_RANK: {
2582 sqlite3_result_int(ctx, pCur->a[pCur->iRow].iRank);
2583 break;
2584 }
2585 case SPELLFIX_COL_DISTANCE: {
2586 sqlite3_result_int(ctx, pCur->a[pCur->iRow].iDistance);
2587 break;
2588 }
2589 case SPELLFIX_COL_LANGID: {
2590 sqlite3_result_int(ctx, pCur->iLang);
2591 break;
2592 }
2593 case SPELLFIX_COL_SCORE: {
2594 sqlite3_result_int(ctx, pCur->a[pCur->iRow].iScore);
2595 break;
2596 }
2597 case SPELLFIX_COL_MATCHLEN: {
2598 int iMatchlen = pCur->a[pCur->iRow].iMatchlen;
2599 if( iMatchlen<0 ){
2600 int nPattern = (int)strlen(pCur->zPattern);
2601 char *zWord = pCur->a[pCur->iRow].zWord;
2602 int nWord = (int)strlen(zWord);
2603
2604 if( nPattern>0 && pCur->zPattern[nPattern-1]=='*' ){
2605 char *zTranslit;
2606 int res;
2607 zTranslit = (char *)transliterate((unsigned char *)zWord, nWord);
2608 if( !zTranslit ) return SQLITE_NOMEM;
2609 res = editdist1(pCur->zPattern, zTranslit, &iMatchlen);
2610 sqlite3_free(zTranslit);
2611 if( res<0 ) return SQLITE_NOMEM;
2612 iMatchlen = translen_to_charlen(zWord, nWord, iMatchlen);
2613 }else{
2614 iMatchlen = utf8Charlen(zWord, nWord);
2615 }
2616 }
2617
2618 sqlite3_result_int(ctx, iMatchlen);
2619 break;
2620 }
2621 case SPELLFIX_COL_PHONEHASH: {
2622 sqlite3_result_text(ctx, pCur->a[pCur->iRow].zHash, -1, SQLITE_STATIC);
2623 break;
2624 }
2625 case SPELLFIX_COL_TOP: {
2626 sqlite3_result_int(ctx, pCur->iTop);
2627 break;
2628 }
2629 case SPELLFIX_COL_SCOPE: {
2630 sqlite3_result_int(ctx, pCur->iScope);
2631 break;
2632 }
2633 case SPELLFIX_COL_SRCHCNT: {
2634 sqlite3_result_int(ctx, pCur->nSearch);
2635 break;
2636 }
2637 default: {
2638 sqlite3_result_null(ctx);
2639 break;
2640 }
2641 }
2642 return SQLITE_OK;
2643 }
2644
2645 /*
2646 ** The rowid.
2647 */
2648 static int spellfix1Rowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
2649 spellfix1_cursor *pCur = (spellfix1_cursor*)cur;
2650 if( pCur->pFullScan ){
2651 *pRowid = sqlite3_column_int64(pCur->pFullScan, 4);
2652 }else{
2653 *pRowid = pCur->a[pCur->iRow].iRowid;
2654 }
2655 return SQLITE_OK;
2656 }
2657
2658 /*
2659 ** The xUpdate() method.
2660 */
2661 static int spellfix1Update(
2662 sqlite3_vtab *pVTab,
2663 int argc,
2664 sqlite3_value **argv,
2665 sqlite_int64 *pRowid
2666 ){
2667 int rc = SQLITE_OK;
2668 sqlite3_int64 rowid, newRowid;
2669 spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
2670 sqlite3 *db = p->db;
2671
2672 if( argc==1 ){
2673 /* A delete operation on the rowid given by argv[0] */
2674 rowid = *pRowid = sqlite3_value_int64(argv[0]);
2675 spellfix1DbExec(&rc, db, "DELETE FROM \"%w\".\"%w_vocab\" "
2676 " WHERE id=%lld",
2677 p->zDbName, p->zTableName, rowid);
2678 }else{
2679 const unsigned char *zWord = sqlite3_value_text(argv[SPELLFIX_COL_WORD+2]);
2680 int nWord = sqlite3_value_bytes(argv[SPELLFIX_COL_WORD+2]);
2681 int iLang = sqlite3_value_int(argv[SPELLFIX_COL_LANGID+2]);
2682 int iRank = sqlite3_value_int(argv[SPELLFIX_COL_RANK+2]);
2683 const unsigned char *zSoundslike =
2684 sqlite3_value_text(argv[SPELLFIX_COL_SOUNDSLIKE+2]);
2685 int nSoundslike = sqlite3_value_bytes(argv[SPELLFIX_COL_SOUNDSLIKE+2]);
2686 char *zK1, *zK2;
2687 int i;
2688 char c;
2689
2690 if( zWord==0 ){
2691 /* Inserts of the form: INSERT INTO table(command) VALUES('xyzzy');
2692 ** cause zWord to be NULL, so we look at the "command" column to see
2693 ** what special actions to take */
2694 const char *zCmd =
2695 (const char*)sqlite3_value_text(argv[SPELLFIX_COL_COMMAND+2]);
2696 if( zCmd==0 ){
2697 pVTab->zErrMsg = sqlite3_mprintf("NOT NULL constraint failed: %s.word",
2698 p->zTableName);
2699 return SQLITE_CONSTRAINT_NOTNULL;
2700 }
2701 if( strcmp(zCmd,"reset")==0 ){
2702 /* Reset the edit cost table (if there is one). */
2703 editDist3ConfigDelete(p->pConfig3);
2704 p->pConfig3 = 0;
2705 return SQLITE_OK;
2706 }
2707 if( strncmp(zCmd,"edit_cost_table=",16)==0 ){
2708 editDist3ConfigDelete(p->pConfig3);
2709 p->pConfig3 = 0;
2710 sqlite3_free(p->zCostTable);
2711 p->zCostTable = spellfix1Dequote(zCmd+16);
2712 if( p->zCostTable==0 ) return SQLITE_NOMEM;
2713 if( p->zCostTable[0]==0 || sqlite3_stricmp(p->zCostTable,"null")==0 ){
2714 sqlite3_free(p->zCostTable);
2715 p->zCostTable = 0;
2716 }
2717 return SQLITE_OK;
2718 }
2719 pVTab->zErrMsg = sqlite3_mprintf("unknown value for %s.command: \"%w\"",
2720 p->zTableName, zCmd);
2721 return SQLITE_ERROR;
2722 }
2723 if( iRank<1 ) iRank = 1;
2724 if( zSoundslike ){
2725 zK1 = (char*)transliterate(zSoundslike, nSoundslike);
2726 }else{
2727 zK1 = (char*)transliterate(zWord, nWord);
2728 }
2729 if( zK1==0 ) return SQLITE_NOMEM;
2730 for(i=0; (c = zK1[i])!=0; i++){
2731 if( c>='A' && c<='Z' ) zK1[i] += 'a' - 'A';
2732 }
2733 zK2 = (char*)phoneticHash((const unsigned char*)zK1, i);
2734 if( zK2==0 ){
2735 sqlite3_free(zK1);
2736 return SQLITE_NOMEM;
2737 }
2738 if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
2739 if( sqlite3_value_type(argv[1])==SQLITE_NULL ){
2740 spellfix1DbExec(&rc, db,
2741 "INSERT INTO \"%w\".\"%w_vocab\"(rank,langid,word,k1,k2) "
2742 "VALUES(%d,%d,%Q,%Q,%Q)",
2743 p->zDbName, p->zTableName,
2744 iRank, iLang, zWord, zK1, zK2
2745 );
2746 }else{
2747 newRowid = sqlite3_value_int64(argv[1]);
2748 spellfix1DbExec(&rc, db,
2749 "INSERT INTO \"%w\".\"%w_vocab\"(id,rank,langid,word,k1,k2) "
2750 "VALUES(%lld,%d,%d,%Q,%Q,%Q)",
2751 p->zDbName, p->zTableName,
2752 newRowid, iRank, iLang, zWord, zK1, zK2
2753 );
2754 }
2755 *pRowid = sqlite3_last_insert_rowid(db);
2756 }else{
2757 rowid = sqlite3_value_int64(argv[0]);
2758 newRowid = *pRowid = sqlite3_value_int64(argv[1]);
2759 spellfix1DbExec(&rc, db,
2760 "UPDATE \"%w\".\"%w_vocab\" SET id=%lld, rank=%d, langid=%d,"
2761 " word=%Q, k1=%Q, k2=%Q WHERE id=%lld",
2762 p->zDbName, p->zTableName, newRowid, iRank, iLang,
2763 zWord, zK1, zK2, rowid
2764 );
2765 }
2766 sqlite3_free(zK1);
2767 sqlite3_free(zK2);
2768 }
2769 return rc;
2770 }
2771
2772 /*
2773 ** Rename the spellfix1 table.
2774 */
2775 static int spellfix1Rename(sqlite3_vtab *pVTab, const char *zNew){
2776 spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
2777 sqlite3 *db = p->db;
2778 int rc = SQLITE_OK;
2779 char *zNewName = sqlite3_mprintf("%s", zNew);
2780 if( zNewName==0 ){
2781 return SQLITE_NOMEM;
2782 }
2783 spellfix1DbExec(&rc, db,
2784 "ALTER TABLE \"%w\".\"%w_vocab\" RENAME TO \"%w_vocab\"",
2785 p->zDbName, p->zTableName, zNewName
2786 );
2787 if( rc==SQLITE_OK ){
2788 sqlite3_free(p->zTableName);
2789 p->zTableName = zNewName;
2790 }else{
2791 sqlite3_free(zNewName);
2792 }
2793 return rc;
2794 }
2795
2796
2797 /*
2798 ** A virtual table module that provides fuzzy search.
2799 */
2800 static sqlite3_module spellfix1Module = {
2801 0, /* iVersion */
2802 spellfix1Create, /* xCreate - handle CREATE VIRTUAL TABLE */
2803 spellfix1Connect, /* xConnect - reconnected to an existing table */
2804 spellfix1BestIndex, /* xBestIndex - figure out how to do a query */
2805 spellfix1Disconnect, /* xDisconnect - close a connection */
2806 spellfix1Destroy, /* xDestroy - handle DROP TABLE */
2807 spellfix1Open, /* xOpen - open a cursor */
2808 spellfix1Close, /* xClose - close a cursor */
2809 spellfix1Filter, /* xFilter - configure scan constraints */
2810 spellfix1Next, /* xNext - advance a cursor */
2811 spellfix1Eof, /* xEof - check for end of scan */
2812 spellfix1Column, /* xColumn - read data */
2813 spellfix1Rowid, /* xRowid - read data */
2814 spellfix1Update, /* xUpdate */
2815 0, /* xBegin */
2816 0, /* xSync */
2817 0, /* xCommit */
2818 0, /* xRollback */
2819 0, /* xFindMethod */
2820 spellfix1Rename, /* xRename */
2821 };
2822
2823 /*
2824 ** Register the various functions and the virtual table.
2825 */
2826 static int spellfix1Register(sqlite3 *db){
2827 int rc = SQLITE_OK;
2828 int i;
2829 rc = sqlite3_create_function(db, "spellfix1_translit", 1, SQLITE_UTF8, 0,
2830 transliterateSqlFunc, 0, 0);
2831 if( rc==SQLITE_OK ){
2832 rc = sqlite3_create_function(db, "spellfix1_editdist", 2, SQLITE_UTF8, 0,
2833 editdistSqlFunc, 0, 0);
2834 }
2835 if( rc==SQLITE_OK ){
2836 rc = sqlite3_create_function(db, "spellfix1_phonehash", 1, SQLITE_UTF8, 0,
2837 phoneticHashSqlFunc, 0, 0);
2838 }
2839 if( rc==SQLITE_OK ){
2840 rc = sqlite3_create_function(db, "spellfix1_scriptcode", 1, SQLITE_UTF8, 0,
2841 scriptCodeSqlFunc, 0, 0);
2842 }
2843 if( rc==SQLITE_OK ){
2844 rc = sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0);
2845 }
2846 if( rc==SQLITE_OK ){
2847 rc = editDist3Install(db);
2848 }
2849
2850 /* Verify sanity of the translit[] table */
2851 for(i=0; i<sizeof(translit)/sizeof(translit[0])-1; i++){
2852 assert( translit[i].cFrom<translit[i+1].cFrom );
2853 }
2854
2855 return rc;
2856 }
2857
2858 #endif /* SQLITE_OMIT_VIRTUALTABLE */
2859
2860 /*
2861 ** Extension load function.
2862 */
2863 #ifdef _WIN32
2864 __declspec(dllexport)
2865 #endif
2866 int sqlite3_spellfix_init(
2867 sqlite3 *db,
2868 char **pzErrMsg,
2869 const sqlite3_api_routines *pApi
2870 ){
2871 SQLITE_EXTENSION_INIT2(pApi);
2872 #ifndef SQLITE_OMIT_VIRTUALTABLE
2873 return spellfix1Register(db);
2874 #endif
2875 return SQLITE_OK;
2876 }