--- /dev/null
+/*
+** 2012 April 10
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This module implements a VIRTUAL TABLE that can be used to search
+** a large vocabulary for close matches. For example, this virtual
+** table can be used to suggest corrections to misspelled words. Or,
+** it could be used with FTS4 to do full-text search using potentially
+** misspelled words.
+**
+** Create an instance of the virtual table this way:
+**
+** CREATE VIRTUAL TABLE demo USING spellfix1;
+**
+** The "spellfix1" term is the name of this module. The "demo" is the
+** name of the virtual table you will be creating. The table is initially
+** empty. You have to populate it with your vocabulary. Suppose you
+** have a list of words in a table named "big_vocabulary". Then do this:
+**
+** INSERT INTO demo(word) SELECT word FROM big_vocabulary;
+**
+** If you intend to use this virtual table in cooperation with an FTS4
+** table (for spelling correctly of search terms) then you can extract
+** the vocabulary using an fts3aux table:
+**
+** INSERT INTO demo(word) SELECT term FROM search_aux WHERE col='*';
+**
+** You can also provide the virtual table with a "rank" for each word.
+** The "rank" is an estimate of how common the word is. Larger numbers
+** mean the word is more common. If you omit the rank when populating
+** the table, then a rank of 1 is assumed. But if you have rank
+** information, you can supply it and the virtual table will show a
+** slight preference for selecting more commonly used terms. To
+** populate the rank from an fts4aux table "search_aux" do something
+** like this:
+**
+** INSERT INTO demo(word,rank)
+** SELECT term, documents FROM search_aux WHERE col='*';
+**
+** To query the virtual table, include a MATCH operator in the WHERE
+** clause. For example:
+**
+** SELECT word FROM demo WHERE word MATCH 'kennasaw';
+**
+** Using a dataset of American place names (derived from
+** http://geonames.usgs.gov/domestic/download_data.htm) the query above
+** returns 20 results beginning with:
+**
+** kennesaw
+** kenosha
+** kenesaw
+** kenaga
+** keanak
+**
+** If you append the character '*' to the end of the pattern, then
+** a prefix search is performed. For example:
+**
+** SELECT word FROM demo WHERE word MATCH 'kennes*';
+**
+** Yields 20 results beginning with:
+**
+** kennesaw
+** kennestone
+** kenneson
+** kenneys
+** keanes
+** keenes
+**
+** The virtual table actually has a unique rowid with five columns plus three
+** extra hidden columns. The columns are as follows:
+**
+** rowid A unique integer number associated with each
+** vocabulary item in the table. This can be used
+** as a foreign key on other tables in the database.
+**
+** word The text of the word that matches the pattern.
+** Both word and pattern can contains unicode characters
+** and can be mixed case.
+**
+** rank This is the rank of the word, as specified in the
+** original INSERT statement.
+**
+** distance This is an edit distance or Levensthein distance going
+** from the pattern to the word.
+**
+** langid This is the language-id of the word. All queries are
+** against a single language-id, which defaults to 0.
+** For any given query this value is the same on all rows.
+**
+** score The score is a combination of rank and distance. The
+** idea is that a lower score is better. The virtual table
+** attempts to find words with the lowest score and
+** by default (unless overridden by ORDER BY) returns
+** results in order of increasing score.
+**
+** top (HIDDEN) For any query, this value is the same on all
+** rows. It is an integer which is the maximum number of
+** rows that will be output. The actually number of rows
+** output might be less than this number, but it will never
+** be greater. The default value for top is 20, but that
+** can be changed for each query by including a term of
+** the form "top=N" in the WHERE clause of the query.
+**
+** scope (HIDDEN) For any query, this value is the same on all
+** rows. The scope is a measure of how widely the virtual
+** table looks for matching words. Smaller values of
+** scope cause a broader search. The scope is normally
+** choosen automatically and is capped at 4. Applications
+** can change the scope by including a term of the form
+** "scope=N" in the WHERE clause of the query. Increasing
+** the scope will make the query run faster, but will reduce
+** the possible corrections.
+**
+** srchcnt (HIDDEN) For any query, this value is the same on all
+** rows. This value is an integer which is the number of
+** of words examined using the edit-distance algorithm to
+** find the top matches that are ultimately displayed. This
+** value is for diagnostic use only.
+**
+** soundslike (HIDDEN) When inserting vocabulary entries, this field
+** can be set to an spelling that matches what the word
+** sounds like. See the DEALING WITH UNUSUAL AND DIFFICULT
+** SPELLINGS section below for details.
+**
+** When inserting into or updating the virtual table, only the rowid, word,
+** rank, and langid may be changes. Any attempt to set or modify the values
+** of distance, score, top, scope, or srchcnt is silently ignored.
+**
+** ALGORITHM
+**
+** A shadow table named "%_vocab" (where the % is replaced by the name of
+** the virtual table; Ex: "demo_vocab" for the "demo" virtual table) is
+** constructed with these columns:
+**
+** id The unique id (INTEGER PRIMARY KEY)
+**
+** rank The rank of word.
+**
+** langid The language id for this entry.
+**
+** word The original UTF8 text of the vocabulary word
+**
+** k1 The word transliterated into lower-case ASCII.
+** There is a standard table of mappings from non-ASCII
+** characters into ASCII. Examples: "æ" -> "ae",
+** "þ" -> "th", "ß" -> "ss", "á" -> "a", ... The
+** accessory function spellfix1_translit(X) will do
+** the non-ASCII to ASCII mapping. The built-in lower(X)
+** function will convert to lower-case. Thus:
+** k1 = lower(spellfix1_translit(word)).
+**
+** k2 This field holds a phonetic code derived from k1. Letters
+** that have similar sounds are mapped into the same symbol.
+** For example, all vowels and vowel clusters become the
+** single symbol "A". And the letters "p", "b", "f", and
+** "v" all become "B". All nasal sounds are represented
+** as "N". And so forth. The mapping is base on
+** ideas found in Soundex, Metaphone, and other
+** long-standing phonetic matching systems. This key can
+** be generated by the function spellfix1_charclass(X).
+** Hence: k2 = spellfix1_charclass(k1)
+**
+** There is also a function for computing the Wagner edit distance or the
+** Levenshtein distance between a pattern and a word. This function
+** is exposed as spellfix1_editdist(X,Y). The edit distance function
+** returns the "cost" of converting X into Y. Some transformations
+** cost more than others. Changing one vowel into a different vowel,
+** for example is relatively cheap, as is doubling a constant, or
+** omitting the second character of a double-constant. Other transformations
+** or more expensive. The idea is that the edit distance function returns
+** a low cost of words that are similar and a higher cost for words
+** that are futher apart. In this implementation, the maximum cost
+** of any single-character edit (delete, insert, or substitute) is 100,
+** with lower costs for some edits (such as transforming vowels).
+**
+** The "score" for a comparison is the edit distance between the pattern
+** and the word, adjusted down by the base-2 logorithm of the word rank.
+** For example, a match with distance 100 but rank 1000 would have a
+** score of 122 (= 100 - log2(1000) + 32) where as a match with distance
+** 100 with a rank of 1 would have a score of 131 (100 - log2(1) + 32).
+** (NB: The constant 32 is added to each score to keep it from going
+** negative in case the edit distance is zero.) In this way, frequently
+** used words get a slightly lower cost which tends to move them toward
+** the top of the list of alternative spellings.
+**
+** A straightforward implementation of a spelling corrector would be
+** to compare the search term against every word in the vocabulary
+** and select the 20 with the lowest scores. However, there will
+** typically be hundreds of thousands or millions of words in the
+** vocabulary, and so this approach is not fast enough.
+**
+** Suppose the term that is being spell-corrected is X. To limit
+** the search space, X is converted to a k2-like key using the
+** equivalent of:
+**
+** key = spellfix1_charclass(lower(spellfix1_translit(X)))
+**
+** This key is then limited to "scope" characters. The default scope
+** value is 4, but an alternative scope can be specified using the
+** "scope=N" term in the WHERE clause. After the key has been truncated,
+** the edit distance is run against every term in the vocabulary that
+** has a k2 value that begins with the abbreviated key.
+**
+** For example, suppose the input word is "Paskagula". The phonetic
+** key is "BACACALA" which is then truncated to 4 characters "BACA".
+** The edit distance is then run on the 4980 entries (out of
+** 272,597 entries total) of the vocabulary whose k2 values begin with
+** BACA, yielding "Pascagoula" as the best match.
+**
+** Only terms of the vocabulary with a matching langid are searched.
+** Hence, the same table can contain entries from multiple languages
+** and only the requested language will be used. The default langid
+** is 0.
+**
+** DEALING WITH UNUSUAL AND DIFFICULT SPELLINGS
+**
+** The algorithm above works quite well for most cases, but there are
+** exceptions. These exceptions can be dealt with by making additional
+** entries in the virtual table using the "soundslike" column.
+**
+** For example, many words of Greek origin begin with letters "ps" where
+** the "p" is silent. Ex: psalm, pseudonym, psoriasis, psyche. In
+** another example, many Scottish surnames can be spelled with an
+** initial "Mac" or "Mc". Thus, "MacKay" and "McKay" are both pronounced
+** the same.
+**
+** Accommodation can be made for words that are not spelled as they
+** sound by making additional entries into the virtual table for the
+** same word, but adding an alternative spelling in the "soundslike"
+** column. For example, the canonical entry for "psalm" would be this:
+**
+** INSERT INTO demo(word) VALUES('psalm');
+**
+** To enhance the ability to correct the spelling of "salm" into
+** "psalm", make an addition entry like this:
+**
+** INSERT INTO demo(word,soundslike) VALUES('psalm','salm');
+**
+** It is ok to make multiple entries for the same word as long as
+** each entry has a different soundslike value. Note that if no
+** soundslike value is specified, the soundslike defaults to the word
+** itself.
+**
+** Listed below are some cases where it might make sense to add additional
+** soundslike entries. The specific entries will depend on the application
+** and the target language.
+**
+** * Silent "p" in words beginning with "ps": psalm, psyche
+**
+** * Silent "p" in words beginning with "pn": pneumonia, pneumatic
+**
+** * Silent "p" in words beginning with "pt": pterodactyl, ptolemaic
+**
+** * Silent "d" in words beginning with "dj": djinn, Djikarta
+**
+** * Silent "k" in words beginning with "kn": knight, Knuthson
+**
+** * Silent "g" in words beginning with "gn": gnarly, gnome, gnat
+**
+** * "Mac" versus "Mc" beginning Scottish surnames
+**
+** * "Tch" sounds in Slavic words: Tchaikovsky vs. Chaykovsky
+**
+** * The letter "j" pronounced like "h" in Spanish: LaJolla
+**
+** * Words beginning with "wr" versus "r": write vs. rite
+**
+** * Miscellanous problem words such as "debt", "tsetse",
+** "Nguyen", "Van Nuyes".
+*/
+#if SQLITE_CORE
+# include "sqliteInt.h"
+#else
+# include <string.h>
+# include <stdio.h>
+# include <stdlib.h>
+# include "sqlite3ext.h"
+ SQLITE_EXTENSION_INIT1
+#endif /* !SQLITE_CORE */
+
+/*
+** Character classes for ASCII characters:
+**
+** 0 '' Silent letters: H W
+** 1 'A' Any vowel: A E I O U (Y)
+** 2 'B' A bilabeal stop or fricative: B F P V
+** 3 'C' Other fricatives or back stops: C G J K Q S X Z
+** 4 'D' Alveolar stops: D T
+** 5 'H' Letter H at the beginning of a word
+** 6 'L' Glides: L R
+** 7 'M' Nasals: M N
+** 8 'W' Letter W at the beginning of a word
+** 9 'Y' Letter Y at the beginning of a word.
+** 10 '9' A digit: 0 1 2 3 4 5 6 7 8 9
+** 11 ' ' White space
+** 12 '?' Other.
+*/
+#define CCLASS_SILENT 0
+#define CCLASS_VOWEL 1
+#define CCLASS_B 2
+#define CCLASS_C 3
+#define CCLASS_D 4
+#define CCLASS_H 5
+#define CCLASS_L 6
+#define CCLASS_M 7
+#define CCLASS_W 8
+#define CCLASS_Y 9
+#define CCLASS_DIGIT 10
+#define CCLASS_SPACE 11
+#define CCLASS_OTHER 12
+
+/*
+** The following table gives the character class for non-initial ASCII
+** characters.
+*/
+static const unsigned char midClass[] = {
+ /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xa xb xc xd xe xf */
+ /* 0x */ 12, 12, 12, 12, 12, 12, 12, 12, 12, 11, 11, 12, 11, 12, 12, 12,
+ /* 1x */ 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+ /* 2x */ 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+ /* 3x */ 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12,
+ /* 4x */ 12, 1, 2, 3, 4, 1, 2, 3, 0, 1, 3, 3, 6, 7, 7, 1,
+ /* 5x */ 2, 3, 6, 3, 4, 1, 2, 0, 3, 1, 3, 12, 12, 12, 12, 12,
+ /* 6x */ 12, 1, 2, 3, 4, 1, 2, 3, 0, 1, 3, 3, 6, 7, 7, 1,
+ /* 7x */ 2, 3, 6, 3, 4, 1, 2, 0, 3, 1, 3, 12, 12, 12, 12, 12,
+};
+
+/*
+** This tables gives the character class for ASCII characters that form the
+** initial character of a word. The only difference from midClass is with
+** the letters H, W, and Y.
+*/
+static const unsigned char initClass[] = {
+ /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xa xb xc xd xe xf */
+ /* 0x */ 12, 12, 12, 12, 12, 12, 12, 12, 12, 11, 11, 12, 11, 12, 12, 12,
+ /* 1x */ 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+ /* 2x */ 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
+ /* 3x */ 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12,
+ /* 4x */ 12, 1, 2, 3, 4, 1, 2, 3, 5, 1, 3, 3, 6, 7, 7, 1,
+ /* 5x */ 2, 3, 6, 3, 4, 1, 2, 8, 3, 9, 3, 12, 12, 12, 12, 12,
+ /* 6x */ 12, 1, 2, 3, 4, 1, 2, 3, 5, 1, 3, 3, 6, 7, 7, 1,
+ /* 7x */ 2, 3, 6, 3, 4, 1, 2, 8, 3, 9, 3, 12, 12, 12, 12, 12,
+};
+
+/*
+** Mapping from the character class number (0-12) to a symbol for each
+** character class. Note that initClass[] can be used to map the class
+** symbol back into the class number.
+*/
+static const unsigned char className[] = ".ABCDHLMWY9 ?";
+
+/*
+** Generate a string of character classes corresponding to the
+** ASCII characters in the input string zIn. If the input is not
+** ASCII then the behavior is undefined.
+**
+** Space to hold the result is obtained from sqlite3_malloc()
+**
+** Return NULL if memory allocation fails.
+*/
+static unsigned char *characterClassString(const unsigned char *zIn, int nIn){
+ unsigned char *zOut = sqlite3_malloc( nIn + 1 );
+ int i;
+ int nOut = 0;
+ char cPrev = 0x77;
+ const unsigned char *aClass = initClass;
+
+ if( zOut==0 ) return 0;
+ for(i=0; i<nIn; i++){
+ unsigned char c = zIn[i];
+ c = aClass[c&0x7f];
+ if( c==CCLASS_OTHER && cPrev!=CCLASS_DIGIT ) continue;
+ cPrev = c;
+ if( c==CCLASS_SILENT ) continue;
+ if( c==CCLASS_SPACE ) continue;
+ aClass = midClass;
+ c = className[c];
+ if( c!=zOut[nOut-1] ) zOut[nOut++] = c;
+ }
+ zOut[nOut] = 0;
+ return zOut;
+}
+
+/*
+** This is an SQL function wrapper around characterClassString(). See
+** the description of characterClassString() for additional information.
+*/
+static void characterClassSqlFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const unsigned char *zIn;
+ unsigned char *zOut;
+
+ zIn = sqlite3_value_text(argv[0]);
+ if( zIn==0 ) return;
+ zOut = characterClassString(zIn, sqlite3_value_bytes(argv[0]));
+ if( zOut==0 ){
+ sqlite3_result_error_nomem(context);
+ }else{
+ sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free);
+ }
+}
+
+/*
+** Return the character class number for a character given its
+** context.
+*/
+static char characterClass(char cPrev, char c){
+ return cPrev==0 ? initClass[c&0x7f] : midClass[c&0x7f];
+}
+
+/*
+** Return the cost of inserting or deleting character c immediately
+** following character cPrev. If cPrev==0, that means c is the first
+** character of the word.
+*/
+static int insertOrDeleteCost(char cPrev, char c){
+ char classC = characterClass(cPrev, c);
+ char classCprev;
+
+ if( classC==CCLASS_SILENT ){
+ /* Insert or delete "silent" characters such as H or W */
+ return 1;
+ }
+ if( cPrev==c ){
+ /* Repeated characters, or miss a repeat */
+ return 10;
+ }
+ classCprev = characterClass(cPrev, cPrev);
+ if( classC==classCprev ){
+ if( classC==CCLASS_VOWEL ){
+ /* Remove or add a new vowel to a vowel cluster */
+ return 15;
+ }else{
+ /* Remove or add a consonant not in the same class */
+ return 50;
+ }
+ }
+
+ /* any other character insertion or deletion */
+ return 100;
+}
+
+/*
+** Divide the insertion cost by this factor when appending to the
+** end of the word.
+*/
+#define FINAL_INS_COST_DIV 4
+
+/*
+** Return the cost of substituting cTo in place of cFrom assuming
+** the previous character is cPrev. If cPrev==0 then cTo is the first
+** character of the word.
+*/
+static int substituteCost(char cPrev, char cFrom, char cTo){
+ char classFrom, classTo;
+ if( cFrom==cTo ){
+ /* Exact match */
+ return 0;
+ }
+ if( cFrom==(cTo^0x20) && ((cTo>='A' && cTo<='Z') || (cTo>='a' && cTo<='z')) ){
+ /* differ only in case */
+ return 0;
+ }
+ classFrom = characterClass(cPrev, cFrom);
+ classTo = characterClass(cPrev, cTo);
+ if( classFrom==classTo ){
+ /* Same character class */
+ return classFrom=='A' ? 25 : 40;
+ }
+ if( classFrom>=CCLASS_B && classFrom<=CCLASS_Y
+ && classTo>=CCLASS_B && classTo<=CCLASS_Y ){
+ /* Convert from one consonant to another, but in a different class */
+ return 75;
+ }
+ /* Any other subsitution */
+ return 100;
+}
+
+/*
+** Given two strings zA and zB which are pure ASCII, return the cost
+** of transforming zA into zB. If zA ends with '*' assume that it is
+** a prefix of zB and give only minimal penalty for extra characters
+** on the end of zB.
+**
+** Smaller numbers mean a closer match.
+**
+** Negative values indicate an error:
+** -1 One of the inputs is NULL
+** -2 Non-ASCII characters on input
+** -3 Unable to allocate memory
+*/
+static int editdist(const char *zA, const char *zB){
+ int nA, nB; /* Number of characters in zA[] and zB[] */
+ int xA, xB; /* Loop counters for zA[] and zB[] */
+ char cA, cB; /* Current character of zA and zB */
+ char cAprev, cBprev; /* Previous character of zA and zB */
+ int d; /* North-west cost value */
+ int dc = 0; /* North-west character value */
+ int res; /* Final result */
+ int *m; /* The cost matrix */
+ char *cx; /* Corresponding character values */
+ int *toFree = 0; /* Malloced space */
+ int mStack[60+15]; /* Stack space to use if not too much is needed */
+
+ /* Early out if either input is NULL */
+ if( zA==0 || zB==0 ) return -1;
+
+ /* Skip any common prefix */
+ while( zA[0] && zA[0]==zB[0] ){ dc = zA[0]; zA++; zB++; }
+ if( zA[0]==0 && zB[0]==0 ) return 0;
+
+#if 0
+ printf("A=\"%s\" B=\"%s\" dc=%c\n", zA, zB, dc?dc:' ');
+#endif
+
+ /* Verify input strings and measure their lengths */
+ for(nA=0; zA[nA]; nA++){
+ if( zA[nA]>127 ) return -2;
+ }
+ for(nB=0; zB[nB]; nB++){
+ if( zB[nB]>127 ) return -2;
+ }
+
+ /* Special processing if either string is empty */
+ if( nA==0 ){
+ cBprev = dc;
+ for(xB=res=0; (cB = zB[xB])!=0; xB++){
+ res += insertOrDeleteCost(cBprev, cB)/FINAL_INS_COST_DIV;
+ cBprev = cB;
+ }
+ return res;
+ }
+ if( nB==0 ){
+ cAprev = dc;
+ for(xA=res=0; (cA = zA[xA])!=0; xA++){
+ res += insertOrDeleteCost(cAprev, cA);
+ cAprev = cA;
+ }
+ return res;
+ }
+
+ /* A is a prefix of B */
+ if( zA[0]=='*' && zA[1]==0 ) return 0;
+
+ /* Allocate and initialize the Wagner matrix */
+ if( nB<(sizeof(mStack)*4)/(sizeof(mStack[0])*5) ){
+ m = mStack;
+ }else{
+ m = toFree = sqlite3_malloc( (nB+1)*5*sizeof(m[0])/4 );
+ if( m==0 ) return -3;
+ }
+ cx = (char*)&m[nB+1];
+
+ /* Compute the Wagner edit distance */
+ m[0] = 0;
+ cx[0] = dc;
+ cBprev = dc;
+ for(xB=1; xB<=nB; xB++){
+ cB = zB[xB-1];
+ cx[xB] = cB;
+ m[xB] = m[xB-1] + insertOrDeleteCost(cBprev, cB);
+ cBprev = cB;
+ }
+ cAprev = dc;
+ for(xA=1; xA<=nA; xA++){
+ int lastA = (xA==nA);
+ cA = zA[xA-1];
+ if( cA=='*' && lastA ) break;
+ d = m[0];
+ dc = cx[0];
+ m[0] = d + insertOrDeleteCost(cAprev, cA);
+ cBprev = 0;
+ for(xB=1; xB<=nB; xB++){
+ int totalCost, insCost, delCost, subCost, ncx;
+ cB = zB[xB-1];
+
+ /* Cost to insert cB */
+ insCost = insertOrDeleteCost(cx[xB-1], cB);
+ if( lastA ) insCost /= FINAL_INS_COST_DIV;
+
+ /* Cost to delete cA */
+ delCost = insertOrDeleteCost(cx[xB], cA);
+
+ /* Cost to substitute cA->cB */
+ subCost = substituteCost(cx[xB-1], cA, cB);
+
+ /* Best cost */
+ totalCost = insCost + m[xB-1];
+ ncx = cB;
+ if( (delCost + m[xB])<totalCost ){
+ totalCost = delCost + m[xB];
+ ncx = cA;
+ }
+ if( (subCost + d)<totalCost ){
+ totalCost = subCost + d;
+ }
+
+#if 0
+ printf("%d,%d d=%4d u=%4d r=%4d dc=%c cA=%c cB=%c"
+ " ins=%4d del=%4d sub=%4d t=%4d ncx=%c\n",
+ xA, xB, d, m[xB], m[xB-1], dc?dc:' ', cA, cB,
+ insCost, delCost, subCost, totalCost, ncx?ncx:' ');
+#endif
+
+ /* Update the matrix */
+ d = m[xB];
+ dc = cx[xB];
+ m[xB] = totalCost;
+ cx[xB] = ncx;
+ cBprev = cB;
+ }
+ cAprev = cA;
+ }
+
+ /* Free the wagner matrix and return the result */
+ if( cA=='*' && nB>nA ){
+ res = m[nA];
+ for(xB=nA+1; xB<=nB; xB++){
+ if( m[xB]<res ) res = m[xB];
+ }
+ }else{
+ res = m[nB];
+ }
+ sqlite3_free(toFree);
+ return res;
+}
+
+/*
+** Function: editdist(A,B)
+**
+** Return the cost of transforming string A into string B. Both strings
+** must be pure ASCII text. If A ends with '*' then it is assumed to be
+** a prefix of B and extra characters on the end of B have minimal additional
+** cost.
+*/
+static void editdistSqlFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ int res = editdist((const char*)sqlite3_value_text(argv[0]),
+ (const char*)sqlite3_value_text(argv[1]));
+ if( res<0 ){
+ if( res==(-3) ){
+ sqlite3_result_error_nomem(context);
+ }else if( res==(-2) ){
+ sqlite3_result_error(context, "non-ASCII input to editdist()", -1);
+ }else{
+ sqlite3_result_error(context, "NULL input to editdist()", -1);
+ }
+ }else{
+ sqlite3_result_int(context, res);
+ }
+}
+
+#if !SQLITE_CORE
+/*
+** This lookup table is used to help decode the first byte of
+** a multi-byte UTF8 character.
+*/
+static const unsigned char sqlite3Utf8Trans1[] = {
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+ 0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
+};
+#endif
+
+/*
+** Return the value of the first UTF-8 character in the string.
+*/
+static int utf8Read(const unsigned char *z, int n, int *pSize){
+ int c, i;
+
+ if( n==0 ){
+ c = i = 0;
+ }else{
+ c = z[0];
+ i = 1;
+ if( c>=0xc0 ){
+ c = sqlite3Utf8Trans1[c-0xc0];
+ while( i<n && (z[i] & 0xc0)==0x80 ){
+ c = (c<<6) + (0x3f & z[i++]);
+ }
+ }
+ }
+ *pSize = i;
+ return c;
+}
+
+/*
+** Table of translations from unicode characters into ASCII.
+*/
+static const struct {
+ unsigned short int cFrom;
+ unsigned char cTo0, cTo1;
+} translit[] = {
+ { 0x00A0, 0x20, 0x00 }, /* to */
+ { 0x00B5, 0x75, 0x00 }, /* µ to u */
+ { 0x00C0, 0x41, 0x00 }, /* À to A */
+ { 0x00C1, 0x41, 0x00 }, /* Á to A */
+ { 0x00C2, 0x41, 0x00 }, /* Â to A */
+ { 0x00C3, 0x41, 0x00 }, /* Ã to A */
+ { 0x00C4, 0x41, 0x65 }, /* Ä to Ae */
+ { 0x00C5, 0x41, 0x61 }, /* Å to Aa */
+ { 0x00C6, 0x41, 0x45 }, /* Æ to AE */
+ { 0x00C7, 0x43, 0x00 }, /* Ç to C */
+ { 0x00C8, 0x45, 0x00 }, /* È to E */
+ { 0x00C9, 0x45, 0x00 }, /* É to E */
+ { 0x00CA, 0x45, 0x00 }, /* Ê to E */
+ { 0x00CB, 0x45, 0x00 }, /* Ë to E */
+ { 0x00CC, 0x49, 0x00 }, /* Ì to I */
+ { 0x00CD, 0x49, 0x00 }, /* Í to I */
+ { 0x00CE, 0x49, 0x00 }, /* Î to I */
+ { 0x00CF, 0x49, 0x00 }, /* Ï to I */
+ { 0x00D0, 0x44, 0x00 }, /* Ð to D */
+ { 0x00D1, 0x4E, 0x00 }, /* Ñ to N */
+ { 0x00D2, 0x4F, 0x00 }, /* Ò to O */
+ { 0x00D3, 0x4F, 0x00 }, /* Ó to O */
+ { 0x00D4, 0x4F, 0x00 }, /* Ô to O */
+ { 0x00D5, 0x4F, 0x00 }, /* Õ to O */
+ { 0x00D6, 0x4F, 0x65 }, /* Ö to Oe */
+ { 0x00D7, 0x78, 0x00 }, /* × to x */
+ { 0x00D8, 0x4F, 0x00 }, /* Ø to O */
+ { 0x00D9, 0x55, 0x00 }, /* Ù to U */
+ { 0x00DA, 0x55, 0x00 }, /* Ú to U */
+ { 0x00DB, 0x55, 0x00 }, /* Û to U */
+ { 0x00DC, 0x55, 0x65 }, /* Ü to Ue */
+ { 0x00DD, 0x59, 0x00 }, /* Ý to Y */
+ { 0x00DE, 0x54, 0x68 }, /* Þ to Th */
+ { 0x00DF, 0x73, 0x73 }, /* ß to ss */
+ { 0x00E0, 0x61, 0x00 }, /* à to a */
+ { 0x00E1, 0x61, 0x00 }, /* á to a */
+ { 0x00E2, 0x61, 0x00 }, /* â to a */
+ { 0x00E3, 0x61, 0x00 }, /* ã to a */
+ { 0x00E4, 0x61, 0x65 }, /* ä to ae */
+ { 0x00E5, 0x61, 0x61 }, /* å to aa */
+ { 0x00E6, 0x61, 0x65 }, /* æ to ae */
+ { 0x00E7, 0x63, 0x00 }, /* ç to c */
+ { 0x00E8, 0x65, 0x00 }, /* è to e */
+ { 0x00E9, 0x65, 0x00 }, /* é to e */
+ { 0x00EA, 0x65, 0x00 }, /* ê to e */
+ { 0x00EB, 0x65, 0x00 }, /* ë to e */
+ { 0x00EC, 0x69, 0x00 }, /* ì to i */
+ { 0x00ED, 0x69, 0x00 }, /* í to i */
+ { 0x00EE, 0x69, 0x00 }, /* î to i */
+ { 0x00EF, 0x69, 0x00 }, /* ï to i */
+ { 0x00F0, 0x64, 0x00 }, /* ð to d */
+ { 0x00F1, 0x6E, 0x00 }, /* ñ to n */
+ { 0x00F2, 0x6F, 0x00 }, /* ò to o */
+ { 0x00F3, 0x6F, 0x00 }, /* ó to o */
+ { 0x00F4, 0x6F, 0x00 }, /* ô to o */
+ { 0x00F5, 0x6F, 0x00 }, /* õ to o */
+ { 0x00F6, 0x6F, 0x65 }, /* ö to oe */
+ { 0x00F7, 0x3A, 0x00 }, /* ÷ to : */
+ { 0x00F8, 0x6F, 0x00 }, /* ø to o */
+ { 0x00F9, 0x75, 0x00 }, /* ù to u */
+ { 0x00FA, 0x75, 0x00 }, /* ú to u */
+ { 0x00FB, 0x75, 0x00 }, /* û to u */
+ { 0x00FC, 0x75, 0x65 }, /* ü to ue */
+ { 0x00FD, 0x79, 0x00 }, /* ý to y */
+ { 0x00FE, 0x74, 0x68 }, /* þ to th */
+ { 0x00FF, 0x79, 0x00 }, /* ÿ to y */
+ { 0x0100, 0x41, 0x00 }, /* Ā to A */
+ { 0x0101, 0x61, 0x00 }, /* ā to a */
+ { 0x0102, 0x41, 0x00 }, /* Ă to A */
+ { 0x0103, 0x61, 0x00 }, /* ă to a */
+ { 0x0104, 0x41, 0x00 }, /* Ą to A */
+ { 0x0105, 0x61, 0x00 }, /* ą to a */
+ { 0x0106, 0x43, 0x00 }, /* Ć to C */
+ { 0x0107, 0x63, 0x00 }, /* ć to c */
+ { 0x0108, 0x43, 0x68 }, /* Ĉ to Ch */
+ { 0x0109, 0x63, 0x68 }, /* ĉ to ch */
+ { 0x010A, 0x43, 0x00 }, /* Ċ to C */
+ { 0x010B, 0x63, 0x00 }, /* ċ to c */
+ { 0x010C, 0x43, 0x00 }, /* Č to C */
+ { 0x010D, 0x63, 0x00 }, /* č to c */
+ { 0x010E, 0x44, 0x00 }, /* Ď to D */
+ { 0x010F, 0x64, 0x00 }, /* ď to d */
+ { 0x0110, 0x44, 0x00 }, /* Đ to D */
+ { 0x0111, 0x64, 0x00 }, /* đ to d */
+ { 0x0112, 0x45, 0x00 }, /* Ē to E */
+ { 0x0113, 0x65, 0x00 }, /* ē to e */
+ { 0x0114, 0x45, 0x00 }, /* Ĕ to E */
+ { 0x0115, 0x65, 0x00 }, /* ĕ to e */
+ { 0x0116, 0x45, 0x00 }, /* Ė to E */
+ { 0x0117, 0x65, 0x00 }, /* ė to e */
+ { 0x0118, 0x45, 0x00 }, /* Ę to E */
+ { 0x0119, 0x65, 0x00 }, /* ę to e */
+ { 0x011A, 0x45, 0x00 }, /* Ě to E */
+ { 0x011B, 0x65, 0x00 }, /* ě to e */
+ { 0x011C, 0x47, 0x68 }, /* Ĝ to Gh */
+ { 0x011D, 0x67, 0x68 }, /* ĝ to gh */
+ { 0x011E, 0x47, 0x00 }, /* Ğ to G */
+ { 0x011F, 0x67, 0x00 }, /* ğ to g */
+ { 0x0120, 0x47, 0x00 }, /* Ġ to G */
+ { 0x0121, 0x67, 0x00 }, /* ġ to g */
+ { 0x0122, 0x47, 0x00 }, /* Ģ to G */
+ { 0x0123, 0x67, 0x00 }, /* ģ to g */
+ { 0x0124, 0x48, 0x68 }, /* Ĥ to Hh */
+ { 0x0125, 0x68, 0x68 }, /* ĥ to hh */
+ { 0x0126, 0x48, 0x00 }, /* Ħ to H */
+ { 0x0127, 0x68, 0x00 }, /* ħ to h */
+ { 0x0128, 0x49, 0x00 }, /* Ĩ to I */
+ { 0x0129, 0x69, 0x00 }, /* ĩ to i */
+ { 0x012A, 0x49, 0x00 }, /* Ī to I */
+ { 0x012B, 0x69, 0x00 }, /* ī to i */
+ { 0x012C, 0x49, 0x00 }, /* Ĭ to I */
+ { 0x012D, 0x69, 0x00 }, /* ĭ to i */
+ { 0x012E, 0x49, 0x00 }, /* Į to I */
+ { 0x012F, 0x69, 0x00 }, /* į to i */
+ { 0x0130, 0x49, 0x00 }, /* İ to I */
+ { 0x0131, 0x69, 0x00 }, /* ı to i */
+ { 0x0132, 0x49, 0x4A }, /* IJ to IJ */
+ { 0x0133, 0x69, 0x6A }, /* ij to ij */
+ { 0x0134, 0x4A, 0x68 }, /* Ĵ to Jh */
+ { 0x0135, 0x6A, 0x68 }, /* ĵ to jh */
+ { 0x0136, 0x4B, 0x00 }, /* Ķ to K */
+ { 0x0137, 0x6B, 0x00 }, /* ķ to k */
+ { 0x0138, 0x6B, 0x00 }, /* ĸ to k */
+ { 0x0139, 0x4C, 0x00 }, /* Ĺ to L */
+ { 0x013A, 0x6C, 0x00 }, /* ĺ to l */
+ { 0x013B, 0x4C, 0x00 }, /* Ļ to L */
+ { 0x013C, 0x6C, 0x00 }, /* ļ to l */
+ { 0x013D, 0x4C, 0x00 }, /* Ľ to L */
+ { 0x013E, 0x6C, 0x00 }, /* ľ to l */
+ { 0x013F, 0x4C, 0x2E }, /* Ŀ to L. */
+ { 0x0140, 0x6C, 0x2E }, /* ŀ to l. */
+ { 0x0141, 0x4C, 0x00 }, /* Ł to L */
+ { 0x0142, 0x6C, 0x00 }, /* ł to l */
+ { 0x0143, 0x4E, 0x00 }, /* Ń to N */
+ { 0x0144, 0x6E, 0x00 }, /* ń to n */
+ { 0x0145, 0x4E, 0x00 }, /* Ņ to N */
+ { 0x0146, 0x6E, 0x00 }, /* ņ to n */
+ { 0x0147, 0x4E, 0x00 }, /* Ň to N */
+ { 0x0148, 0x6E, 0x00 }, /* ň to n */
+ { 0x0149, 0x27, 0x6E }, /* ʼn to 'n */
+ { 0x014A, 0x4E, 0x47 }, /* Ŋ to NG */
+ { 0x014B, 0x6E, 0x67 }, /* ŋ to ng */
+ { 0x014C, 0x4F, 0x00 }, /* Ō to O */
+ { 0x014D, 0x6F, 0x00 }, /* ō to o */
+ { 0x014E, 0x4F, 0x00 }, /* Ŏ to O */
+ { 0x014F, 0x6F, 0x00 }, /* ŏ to o */
+ { 0x0150, 0x4F, 0x00 }, /* Ő to O */
+ { 0x0151, 0x6F, 0x00 }, /* ő to o */
+ { 0x0152, 0x4F, 0x45 }, /* Πto OE */
+ { 0x0153, 0x6F, 0x65 }, /* œ to oe */
+ { 0x0154, 0x52, 0x00 }, /* Ŕ to R */
+ { 0x0155, 0x72, 0x00 }, /* ŕ to r */
+ { 0x0156, 0x52, 0x00 }, /* Ŗ to R */
+ { 0x0157, 0x72, 0x00 }, /* ŗ to r */
+ { 0x0158, 0x52, 0x00 }, /* Ř to R */
+ { 0x0159, 0x72, 0x00 }, /* ř to r */
+ { 0x015A, 0x53, 0x00 }, /* Ś to S */
+ { 0x015B, 0x73, 0x00 }, /* ś to s */
+ { 0x015C, 0x53, 0x68 }, /* Ŝ to Sh */
+ { 0x015D, 0x73, 0x68 }, /* ŝ to sh */
+ { 0x015E, 0x53, 0x00 }, /* Ş to S */
+ { 0x015F, 0x73, 0x00 }, /* ş to s */
+ { 0x0160, 0x53, 0x00 }, /* Š to S */
+ { 0x0161, 0x73, 0x00 }, /* š to s */
+ { 0x0162, 0x54, 0x00 }, /* Ţ to T */
+ { 0x0163, 0x74, 0x00 }, /* ţ to t */
+ { 0x0164, 0x54, 0x00 }, /* Ť to T */
+ { 0x0165, 0x74, 0x00 }, /* ť to t */
+ { 0x0166, 0x54, 0x00 }, /* Ŧ to T */
+ { 0x0167, 0x74, 0x00 }, /* ŧ to t */
+ { 0x0168, 0x55, 0x00 }, /* Ũ to U */
+ { 0x0169, 0x75, 0x00 }, /* ũ to u */
+ { 0x016A, 0x55, 0x00 }, /* Ū to U */
+ { 0x016B, 0x75, 0x00 }, /* ū to u */
+ { 0x016C, 0x55, 0x00 }, /* Ŭ to U */
+ { 0x016D, 0x75, 0x00 }, /* ŭ to u */
+ { 0x016E, 0x55, 0x00 }, /* Ů to U */
+ { 0x016F, 0x75, 0x00 }, /* ů to u */
+ { 0x0170, 0x55, 0x00 }, /* Ű to U */
+ { 0x0171, 0x75, 0x00 }, /* ű to u */
+ { 0x0172, 0x55, 0x00 }, /* Ų to U */
+ { 0x0173, 0x75, 0x00 }, /* ų to u */
+ { 0x0174, 0x57, 0x00 }, /* Ŵ to W */
+ { 0x0175, 0x77, 0x00 }, /* ŵ to w */
+ { 0x0176, 0x59, 0x00 }, /* Ŷ to Y */
+ { 0x0177, 0x79, 0x00 }, /* ŷ to y */
+ { 0x0178, 0x59, 0x00 }, /* Ÿ to Y */
+ { 0x0179, 0x5A, 0x00 }, /* Ź to Z */
+ { 0x017A, 0x7A, 0x00 }, /* ź to z */
+ { 0x017B, 0x5A, 0x00 }, /* Ż to Z */
+ { 0x017C, 0x7A, 0x00 }, /* ż to z */
+ { 0x017D, 0x5A, 0x00 }, /* Ž to Z */
+ { 0x017E, 0x7A, 0x00 }, /* ž to z */
+ { 0x017F, 0x73, 0x00 }, /* ſ to s */
+ { 0x0192, 0x66, 0x00 }, /* ƒ to f */
+ { 0x0218, 0x53, 0x00 }, /* Ș to S */
+ { 0x0219, 0x73, 0x00 }, /* ș to s */
+ { 0x021A, 0x54, 0x00 }, /* Ț to T */
+ { 0x021B, 0x74, 0x00 }, /* ț to t */
+ { 0x0386, 0x41, 0x00 }, /* Ά to A */
+ { 0x0388, 0x45, 0x00 }, /* Έ to E */
+ { 0x0389, 0x49, 0x00 }, /* Ή to I */
+ { 0x038A, 0x49, 0x00 }, /* Ί to I */
+ { 0x038C, 0x4f, 0x00 }, /* Ό to O */
+ { 0x038E, 0x59, 0x00 }, /* Ύ to Y */
+ { 0x038F, 0x4f, 0x00 }, /* Ώ to O */
+ { 0x0390, 0x69, 0x00 }, /* ΐ to i */
+ { 0x0391, 0x41, 0x00 }, /* Α to A */
+ { 0x0392, 0x42, 0x00 }, /* Β to B */
+ { 0x0393, 0x47, 0x00 }, /* Γ to G */
+ { 0x0394, 0x44, 0x00 }, /* Δ to D */
+ { 0x0395, 0x45, 0x00 }, /* Ε to E */
+ { 0x0396, 0x5a, 0x00 }, /* Ζ to Z */
+ { 0x0397, 0x49, 0x00 }, /* Η to I */
+ { 0x0398, 0x54, 0x68 }, /* Θ to Th */
+ { 0x0399, 0x49, 0x00 }, /* Ι to I */
+ { 0x039A, 0x4b, 0x00 }, /* Κ to K */
+ { 0x039B, 0x4c, 0x00 }, /* Λ to L */
+ { 0x039C, 0x4d, 0x00 }, /* Μ to M */
+ { 0x039D, 0x4e, 0x00 }, /* Ν to N */
+ { 0x039E, 0x58, 0x00 }, /* Ξ to X */
+ { 0x039F, 0x4f, 0x00 }, /* Ο to O */
+ { 0x03A0, 0x50, 0x00 }, /* Π to P */
+ { 0x03A1, 0x52, 0x00 }, /* Ρ to R */
+ { 0x03A3, 0x53, 0x00 }, /* Σ to S */
+ { 0x03A4, 0x54, 0x00 }, /* Τ to T */
+ { 0x03A5, 0x59, 0x00 }, /* Υ to Y */
+ { 0x03A6, 0x46, 0x00 }, /* Φ to F */
+ { 0x03A7, 0x43, 0x68 }, /* Χ to Ch */
+ { 0x03A8, 0x50, 0x73 }, /* Ψ to Ps */
+ { 0x03A9, 0x4f, 0x00 }, /* Ω to O */
+ { 0x03AA, 0x49, 0x00 }, /* Ϊ to I */
+ { 0x03AB, 0x59, 0x00 }, /* Ϋ to Y */
+ { 0x03AC, 0x61, 0x00 }, /* ά to a */
+ { 0x03AD, 0x65, 0x00 }, /* έ to e */
+ { 0x03AE, 0x69, 0x00 }, /* ή to i */
+ { 0x03AF, 0x69, 0x00 }, /* ί to i */
+ { 0x03B1, 0x61, 0x00 }, /* α to a */
+ { 0x03B2, 0x62, 0x00 }, /* β to b */
+ { 0x03B3, 0x67, 0x00 }, /* γ to g */
+ { 0x03B4, 0x64, 0x00 }, /* δ to d */
+ { 0x03B5, 0x65, 0x00 }, /* ε to e */
+ { 0x03B6, 0x7a, 0x00 }, /* ζ to z */
+ { 0x03B7, 0x69, 0x00 }, /* η to i */
+ { 0x03B8, 0x74, 0x68 }, /* θ to th */
+ { 0x03B9, 0x69, 0x00 }, /* ι to i */
+ { 0x03BA, 0x6b, 0x00 }, /* κ to k */
+ { 0x03BB, 0x6c, 0x00 }, /* λ to l */
+ { 0x03BC, 0x6d, 0x00 }, /* μ to m */
+ { 0x03BD, 0x6e, 0x00 }, /* ν to n */
+ { 0x03BE, 0x78, 0x00 }, /* ξ to x */
+ { 0x03BF, 0x6f, 0x00 }, /* ο to o */
+ { 0x03C0, 0x70, 0x00 }, /* π to p */
+ { 0x03C1, 0x72, 0x00 }, /* ρ to r */
+ { 0x03C3, 0x73, 0x00 }, /* σ to s */
+ { 0x03C4, 0x74, 0x00 }, /* τ to t */
+ { 0x03C5, 0x79, 0x00 }, /* υ to y */
+ { 0x03C6, 0x66, 0x00 }, /* φ to f */
+ { 0x03C7, 0x63, 0x68 }, /* χ to ch */
+ { 0x03C8, 0x70, 0x73 }, /* ψ to ps */
+ { 0x03C9, 0x6f, 0x00 }, /* ω to o */
+ { 0x03CA, 0x69, 0x00 }, /* ϊ to i */
+ { 0x03CB, 0x79, 0x00 }, /* ϋ to y */
+ { 0x03CC, 0x6f, 0x00 }, /* ό to o */
+ { 0x03CD, 0x79, 0x00 }, /* ύ to y */
+ { 0x03CE, 0x69, 0x00 }, /* ώ to i */
+ { 0x0400, 0x45, 0x00 }, /* Ѐ to E */
+ { 0x0401, 0x45, 0x00 }, /* Ё to E */
+ { 0x0402, 0x44, 0x00 }, /* Ђ to D */
+ { 0x0403, 0x47, 0x00 }, /* Ѓ to G */
+ { 0x0404, 0x45, 0x00 }, /* Є to E */
+ { 0x0405, 0x5a, 0x00 }, /* Ѕ to Z */
+ { 0x0406, 0x49, 0x00 }, /* І to I */
+ { 0x0407, 0x49, 0x00 }, /* Ї to I */
+ { 0x0408, 0x4a, 0x00 }, /* Ј to J */
+ { 0x0409, 0x49, 0x00 }, /* Љ to I */
+ { 0x040A, 0x4e, 0x00 }, /* Њ to N */
+ { 0x040B, 0x44, 0x00 }, /* Ћ to D */
+ { 0x040C, 0x4b, 0x00 }, /* Ќ to K */
+ { 0x040D, 0x49, 0x00 }, /* Ѝ to I */
+ { 0x040E, 0x55, 0x00 }, /* Ў to U */
+ { 0x040F, 0x44, 0x00 }, /* Џ to D */
+ { 0x0410, 0x41, 0x00 }, /* А to A */
+ { 0x0411, 0x42, 0x00 }, /* Б to B */
+ { 0x0412, 0x56, 0x00 }, /* В to V */
+ { 0x0413, 0x47, 0x00 }, /* Г to G */
+ { 0x0414, 0x44, 0x00 }, /* Д to D */
+ { 0x0415, 0x45, 0x00 }, /* Е to E */
+ { 0x0416, 0x5a, 0x68 }, /* Ж to Zh */
+ { 0x0417, 0x5a, 0x00 }, /* З to Z */
+ { 0x0418, 0x49, 0x00 }, /* И to I */
+ { 0x0419, 0x49, 0x00 }, /* Й to I */
+ { 0x041A, 0x4b, 0x00 }, /* К to K */
+ { 0x041B, 0x4c, 0x00 }, /* Л to L */
+ { 0x041C, 0x4d, 0x00 }, /* М to M */
+ { 0x041D, 0x4e, 0x00 }, /* Н to N */
+ { 0x041E, 0x4f, 0x00 }, /* О to O */
+ { 0x041F, 0x50, 0x00 }, /* П to P */
+ { 0x0420, 0x52, 0x00 }, /* Р to R */
+ { 0x0421, 0x53, 0x00 }, /* С to S */
+ { 0x0422, 0x54, 0x00 }, /* Т to T */
+ { 0x0423, 0x55, 0x00 }, /* У to U */
+ { 0x0424, 0x46, 0x00 }, /* Ф to F */
+ { 0x0425, 0x4b, 0x68 }, /* Х to Kh */
+ { 0x0426, 0x54, 0x63 }, /* Ц to Tc */
+ { 0x0427, 0x43, 0x68 }, /* Ч to Ch */
+ { 0x0428, 0x53, 0x68 }, /* Ш to Sh */
+ { 0x0429, 0x53, 0x68 }, /* Щ to Shch */
+ { 0x042B, 0x59, 0x00 }, /* Ы to Y */
+ { 0x042D, 0x45, 0x00 }, /* Э to E */
+ { 0x042E, 0x49, 0x75 }, /* Ю to Iu */
+ { 0x042F, 0x49, 0x61 }, /* Я to Ia */
+ { 0x0430, 0x61, 0x00 }, /* а to a */
+ { 0x0431, 0x62, 0x00 }, /* б to b */
+ { 0x0432, 0x76, 0x00 }, /* в to v */
+ { 0x0433, 0x67, 0x00 }, /* г to g */
+ { 0x0434, 0x64, 0x00 }, /* д to d */
+ { 0x0435, 0x65, 0x00 }, /* е to e */
+ { 0x0436, 0x7a, 0x68 }, /* ж to zh */
+ { 0x0437, 0x7a, 0x00 }, /* з to z */
+ { 0x0438, 0x69, 0x00 }, /* и to i */
+ { 0x0439, 0x69, 0x00 }, /* й to i */
+ { 0x043A, 0x6b, 0x00 }, /* к to k */
+ { 0x043B, 0x6c, 0x00 }, /* л to l */
+ { 0x043C, 0x6d, 0x00 }, /* м to m */
+ { 0x043D, 0x6e, 0x00 }, /* н to n */
+ { 0x043E, 0x6f, 0x00 }, /* о to o */
+ { 0x043F, 0x70, 0x00 }, /* п to p */
+ { 0x0440, 0x72, 0x00 }, /* р to r */
+ { 0x0441, 0x73, 0x00 }, /* с to s */
+ { 0x0442, 0x74, 0x00 }, /* т to t */
+ { 0x0443, 0x75, 0x00 }, /* у to u */
+ { 0x0444, 0x66, 0x00 }, /* ф to f */
+ { 0x0445, 0x6b, 0x68 }, /* х to kh */
+ { 0x0446, 0x74, 0x63 }, /* ц to tc */
+ { 0x0447, 0x63, 0x68 }, /* ч to ch */
+ { 0x0448, 0x73, 0x68 }, /* ш to sh */
+ { 0x0449, 0x73, 0x68 }, /* щ to shch */
+ { 0x044B, 0x79, 0x00 }, /* ы to y */
+ { 0x044D, 0x65, 0x00 }, /* э to e */
+ { 0x044E, 0x69, 0x75 }, /* ю to iu */
+ { 0x044F, 0x69, 0x61 }, /* я to ia */
+ { 0x0450, 0x65, 0x00 }, /* ѐ to e */
+ { 0x0451, 0x65, 0x00 }, /* ё to e */
+ { 0x0452, 0x64, 0x00 }, /* ђ to d */
+ { 0x0453, 0x67, 0x00 }, /* ѓ to g */
+ { 0x0454, 0x65, 0x00 }, /* є to e */
+ { 0x0455, 0x7a, 0x00 }, /* ѕ to z */
+ { 0x0456, 0x69, 0x00 }, /* і to i */
+ { 0x0457, 0x69, 0x00 }, /* ї to i */
+ { 0x0458, 0x6a, 0x00 }, /* ј to j */
+ { 0x0459, 0x69, 0x00 }, /* љ to i */
+ { 0x045A, 0x6e, 0x00 }, /* њ to n */
+ { 0x045B, 0x64, 0x00 }, /* ћ to d */
+ { 0x045C, 0x6b, 0x00 }, /* ќ to k */
+ { 0x045D, 0x69, 0x00 }, /* ѝ to i */
+ { 0x045E, 0x75, 0x00 }, /* ў to u */
+ { 0x045F, 0x64, 0x00 }, /* џ to d */
+ { 0x1E02, 0x42, 0x00 }, /* Ḃ to B */
+ { 0x1E03, 0x62, 0x00 }, /* ḃ to b */
+ { 0x1E0A, 0x44, 0x00 }, /* Ḋ to D */
+ { 0x1E0B, 0x64, 0x00 }, /* ḋ to d */
+ { 0x1E1E, 0x46, 0x00 }, /* Ḟ to F */
+ { 0x1E1F, 0x66, 0x00 }, /* ḟ to f */
+ { 0x1E40, 0x4D, 0x00 }, /* Ṁ to M */
+ { 0x1E41, 0x6D, 0x00 }, /* ṁ to m */
+ { 0x1E56, 0x50, 0x00 }, /* Ṗ to P */
+ { 0x1E57, 0x70, 0x00 }, /* ṗ to p */
+ { 0x1E60, 0x53, 0x00 }, /* Ṡ to S */
+ { 0x1E61, 0x73, 0x00 }, /* ṡ to s */
+ { 0x1E6A, 0x54, 0x00 }, /* Ṫ to T */
+ { 0x1E6B, 0x74, 0x00 }, /* ṫ to t */
+ { 0x1E80, 0x57, 0x00 }, /* Ẁ to W */
+ { 0x1E81, 0x77, 0x00 }, /* ẁ to w */
+ { 0x1E82, 0x57, 0x00 }, /* Ẃ to W */
+ { 0x1E83, 0x77, 0x00 }, /* ẃ to w */
+ { 0x1E84, 0x57, 0x00 }, /* Ẅ to W */
+ { 0x1E85, 0x77, 0x00 }, /* ẅ to w */
+ { 0x1EF2, 0x59, 0x00 }, /* Ỳ to Y */
+ { 0x1EF3, 0x79, 0x00 }, /* ỳ to y */
+ { 0xFB00, 0x66, 0x66 }, /* ff to ff */
+ { 0xFB01, 0x66, 0x69 }, /* fi to fi */
+ { 0xFB02, 0x66, 0x6C }, /* fl to fl */
+ { 0xFB05, 0x73, 0x74 }, /* ſt to st */
+ { 0xFB06, 0x73, 0x74 }, /* st to st */
+};
+
+/*
+** Convert the input string from UTF-8 into pure ASCII by converting
+** all non-ASCII characters to some combination of characters in the
+** ASCII subset.
+**
+** The returned string might contain more characters than the input.
+**
+** Space to hold the returned string comes from sqlite3_malloc() and
+** should be freed by the caller.
+*/
+static unsigned char *transliterate(const unsigned char *zIn, int nIn){
+ unsigned char *zOut = sqlite3_malloc( nIn*4 + 1 );
+ int i, c, sz, nOut;
+ if( zOut==0 ) return 0;
+ i = nOut = 0;
+ while( i<nIn ){
+ c = utf8Read(zIn, nIn, &sz);
+ zIn += sz;
+ nIn -= sz;
+ if( c<=127 ){
+ zOut[nOut++] = c;
+ }else{
+ int xTop, xBtm, x;
+ xTop = sizeof(translit)/sizeof(translit[0]) - 1;
+ xBtm = 0;
+ while( xTop>=xBtm ){
+ x = (xTop + xBtm)/2;
+ if( translit[x].cFrom==c ){
+ zOut[nOut++] = translit[x].cTo0;
+ if( translit[x].cTo1 ){
+ zOut[nOut++] = translit[x].cTo1;
+ /* Add an extra "ch" after the "sh" for Щ and щ */
+ if( c==0x0429 || c== 0x0449 ){
+ zOut[nOut++] = 'c';
+ zOut[nOut++] = 'h';
+ }
+ }
+ c = 0;
+ break;
+ }else if( translit[x].cFrom>c ){
+ xTop = x-1;
+ }else{
+ xBtm = x+1;
+ }
+ }
+ if( c ) zOut[nOut++] = '?';
+ }
+ }
+ zOut[nOut] = 0;
+ return zOut;
+}
+
+/*
+** spellfix1_translit(X)
+**
+** Convert a string that contains non-ASCII Roman characters into
+** pure ASCII.
+*/
+static void transliterateSqlFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const unsigned char *zIn = sqlite3_value_text(argv[0]);
+ int nIn = sqlite3_value_bytes(argv[0]);
+ unsigned char *zOut = transliterate(zIn, nIn);
+ if( zOut==0 ){
+ sqlite3_result_error_nomem(context);
+ }else{
+ sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free);
+ }
+}
+
+/*
+** spellfix1_scriptcode(X)
+**
+** Try to determine the dominant script used by the word X and return
+** its ISO 15924 numeric code.
+**
+** The current implementation only understands the following scripts:
+**
+** 215 (Latin)
+** 220 (Cyrillic)
+** 200 (Greek)
+**
+** This routine will return 998 if the input X contains characters from
+** two or more of the above scripts or 999 if X contains no characters
+** from any of the above scripts.
+*/
+static void scriptCodeSqlFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const unsigned char *zIn = sqlite3_value_text(argv[0]);
+ int nIn = sqlite3_value_bytes(argv[0]);
+ int c, sz;
+ int scriptMask = 0;
+ int res;
+# define SCRIPT_LATIN 0x0001
+# define SCRIPT_CYRILLIC 0x0002
+# define SCRIPT_GREEK 0x0004
+
+ while( nIn>0 ){
+ c = utf8Read(zIn, nIn, &sz);
+ zIn += sz;
+ nIn -= sz;
+ if( c<0x02af ){
+ scriptMask |= SCRIPT_LATIN;
+ }else if( c>=0x0400 && c<=0x04ff ){
+ scriptMask |= SCRIPT_CYRILLIC;
+ }else if( c>=0x0386 && c<=0x03ce ){
+ scriptMask |= SCRIPT_GREEK;
+ }
+ }
+ switch( scriptMask ){
+ case 0: res = 999; break;
+ case SCRIPT_LATIN: res = 215; break;
+ case SCRIPT_CYRILLIC: res = 220; break;
+ case SCRIPT_GREEK: res = 200; break;
+ default: res = 998; break;
+ }
+ sqlite3_result_int(context, res);
+}
+
+/*****************************************************************************
+** Fuzzy-search virtual table
+*****************************************************************************/
+
+typedef struct spellfix1_vtab spellfix1_vtab;
+typedef struct spellfix1_cursor spellfix1_cursor;
+
+/* Fuzzy-search virtual table object */
+struct spellfix1_vtab {
+ sqlite3_vtab base; /* Base class - must be first */
+ sqlite3 *db; /* Database connection */
+ char *zDbName; /* Name of database holding this table */
+ char *zTableName; /* Name of the virtual table */
+};
+
+/* Fuzzy-search cursor object */
+struct spellfix1_cursor {
+ sqlite3_vtab_cursor base; /* Base class - must be first */
+ spellfix1_vtab *pVTab; /* The table to which this cursor belongs */
+ int nRow; /* Number of rows of content */
+ int nAlloc; /* Number of allocated rows */
+ int iRow; /* Current row of content */
+ int iLang; /* Value of the lang= constraint */
+ int iTop; /* Value of the top= constraint */
+ int iScope; /* Value of the scope= constraint */
+ int nSearch; /* Number of vocabulary items checked */
+ struct spellfix1_row { /* For each row of content */
+ sqlite3_int64 iRowid; /* Rowid for this row */
+ char *zWord; /* Text for this row */
+ int iRank; /* Rank for this row */
+ int iDistance; /* Distance from pattern for this row */
+ int iScore; /* Score for sorting */
+ } *a;
+};
+
+/*
+** Construct one or more SQL statements from the format string given
+** and then evaluate those statements. The success code is written
+** into *pRc.
+**
+** If *pRc is initially non-zero then this routine is a no-op.
+*/
+static void spellfix1DbExec(
+ int *pRc, /* Success code */
+ sqlite3 *db, /* Database in which to run SQL */
+ const char *zFormat, /* Format string for SQL */
+ ... /* Arguments to the format string */
+){
+ va_list ap;
+ char *zSql;
+ if( *pRc ) return;
+ va_start(ap, zFormat);
+ zSql = sqlite3_vmprintf(zFormat, ap);
+ va_end(ap);
+ if( zSql==0 ){
+ *pRc = SQLITE_NOMEM;
+ }else{
+ *pRc = sqlite3_exec(db, zSql, 0, 0, 0);
+ sqlite3_free(zSql);
+ }
+}
+
+/*
+** xDisconnect/xDestroy method for the fuzzy-search module.
+*/
+static int spellfix1Uninit(int isDestroy, sqlite3_vtab *pVTab){
+ spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+ int rc = SQLITE_OK;
+ if( isDestroy ){
+ sqlite3 *db = p->db;
+ spellfix1DbExec(&rc, db, "DROP TABLE IF EXISTS \"%w\".\"%w_vocab\"",
+ p->zDbName, p->zTableName);
+ }
+ if( rc==SQLITE_OK ){
+ sqlite3_free(p->zTableName);
+ sqlite3_free(p);
+ }
+ return rc;
+}
+static int spellfix1Disconnect(sqlite3_vtab *pVTab){
+ return spellfix1Uninit(0, pVTab);
+}
+static int spellfix1Destroy(sqlite3_vtab *pVTab){
+ return spellfix1Uninit(1, pVTab);
+}
+
+/*
+** xConnect/xCreate method for the spellfix1 module. Arguments are:
+**
+** argv[0] -> module name ("spellfix1")
+** argv[1] -> database name
+** argv[2] -> table name
+** argv[3].. -> optional arguments (currently ignored)
+*/
+static int spellfix1Init(
+ int isCreate,
+ sqlite3 *db,
+ void *pAux,
+ int argc, const char *const*argv,
+ sqlite3_vtab **ppVTab,
+ char **pzErr
+){
+ spellfix1_vtab *pNew = 0;
+ const char *zModule = argv[0];
+ const char *zDbName = argv[1];
+ const char *zTableName = argv[2];
+ int nDbName;
+ int rc = SQLITE_OK;
+
+ if( argc<3 ){
+ *pzErr = sqlite3_mprintf(
+ "%s: wrong number of CREATE VIRTUAL TABLE arguments", argv[0]
+ );
+ rc = SQLITE_ERROR;
+ }else{
+ nDbName = strlen(zDbName);
+ pNew = sqlite3_malloc( sizeof(*pNew) + nDbName + 1);
+ if( pNew==0 ){
+ rc = SQLITE_NOMEM;
+ }else{
+ memset(pNew, 0, sizeof(*pNew));
+ pNew->zDbName = (char*)&pNew[1];
+ memcpy(pNew->zDbName, zDbName, nDbName+1);
+ pNew->zTableName = sqlite3_mprintf("%s", zTableName);
+ pNew->db = db;
+ if( pNew->zTableName==0 ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = sqlite3_declare_vtab(db,
+ "CREATE TABLE x(word,rank,distance,langid,"
+ "score,top HIDDEN,scope HIDDEN,srchcnt HIDDEN,"
+ "soundslike HIDDEN)"
+ );
+ }
+ if( rc==SQLITE_OK && isCreate ){
+ sqlite3_uint64 r;
+ spellfix1DbExec(&rc, db,
+ "CREATE TABLE IF NOT EXISTS \"%w\".\"%w_vocab\"(\n"
+ " id INTEGER PRIMARY KEY,\n"
+ " rank INT,\n"
+ " langid INT,\n"
+ " word TEXT,\n"
+ " k1 TEXT,\n"
+ " k2 TEXT\n"
+ ");\n",
+ zDbName, zTableName
+ );
+ sqlite3_randomness(sizeof(r), &r);
+ spellfix1DbExec(&rc, db,
+ "CREATE INDEX IF NOT EXISTS \"%w\".\"%w_index_%llx\" "
+ "ON \"%w_vocab\"(langid,k2);",
+ zDbName, zModule, r, zTableName
+ );
+ }
+ }
+ }
+
+ *ppVTab = (sqlite3_vtab *)pNew;
+ return rc;
+}
+
+/*
+** The xConnect and xCreate methods
+*/
+static int spellfix1Connect(
+ sqlite3 *db,
+ void *pAux,
+ int argc, const char *const*argv,
+ sqlite3_vtab **ppVTab,
+ char **pzErr
+){
+ return spellfix1Init(0, db, pAux, argc, argv, ppVTab, pzErr);
+}
+static int spellfix1Create(
+ sqlite3 *db,
+ void *pAux,
+ int argc, const char *const*argv,
+ sqlite3_vtab **ppVTab,
+ char **pzErr
+){
+ return spellfix1Init(1, db, pAux, argc, argv, ppVTab, pzErr);
+}
+
+/*
+** Reset a cursor so that it contains zero rows of content but holds
+** space for N rows.
+*/
+static void spellfix1ResetCursor(spellfix1_cursor *pCur, int N){
+ int i;
+ for(i=0; i<pCur->nRow; i++){
+ sqlite3_free(pCur->a[i].zWord);
+ }
+ pCur->a = sqlite3_realloc(pCur->a, sizeof(pCur->a[0])*N);
+ pCur->nAlloc = N;
+ pCur->nRow = 0;
+ pCur->iRow = 0;
+ pCur->nSearch = 0;
+}
+
+/*
+** Close a fuzzy-search cursor.
+*/
+static int spellfix1Close(sqlite3_vtab_cursor *cur){
+ spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+ spellfix1ResetCursor(pCur, 0);
+ sqlite3_free(pCur);
+ return SQLITE_OK;
+}
+
+/*
+** Search for terms of these forms:
+**
+** (A) word MATCH $str
+** (B) langid == $langid
+** (C) top = $top
+** (D) scope = $scope
+**
+** The plan number is a bit mask formed with these bits:
+**
+** 0x01 (A) is found
+** 0x02 (B) is found
+** 0x04 (C) is found
+** 0x08 (D) is found
+**
+** filter.argv[*] values contains $str, $langid, $top, and $scope,
+** if specified and in that order.
+*/
+static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+ int iPlan = 0;
+ int iLangTerm = -1;
+ int iTopTerm = -1;
+ int iScopeTerm = -1;
+ int i;
+ const struct sqlite3_index_constraint *pConstraint;
+ pConstraint = pIdxInfo->aConstraint;
+ for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+ if( pConstraint->usable==0 ) continue;
+
+ /* Terms of the form: word MATCH $str */
+ if( (iPlan & 1)==0
+ && pConstraint->iColumn==0
+ && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH
+ ){
+ iPlan |= 1;
+ pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+ pIdxInfo->aConstraintUsage[i].omit = 1;
+ }
+
+ /* Terms of the form: langid = $langid */
+ if( (iPlan & 2)==0
+ && pConstraint->iColumn==3
+ && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+ ){
+ iPlan |= 2;
+ iLangTerm = i;
+ }
+
+ /* Terms of the form: top = $top */
+ if( (iPlan & 4)==0
+ && pConstraint->iColumn==5
+ && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+ ){
+ iPlan |= 4;
+ iTopTerm = i;
+ }
+
+ /* Terms of the form: scope = $scope */
+ if( (iPlan & 8)==0
+ && pConstraint->iColumn==6
+ && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+ ){
+ iPlan |= 8;
+ iScopeTerm = i;
+ }
+ }
+ if( iPlan&1 ){
+ int idx = 2;
+ pIdxInfo->idxNum = iPlan;
+ if( pIdxInfo->nOrderBy==1
+ && pIdxInfo->aOrderBy[0].iColumn==4
+ && pIdxInfo->aOrderBy[0].desc==0
+ ){
+ pIdxInfo->orderByConsumed = 1; /* Default order by iScore */
+ }
+ if( iPlan&2 ){
+ pIdxInfo->aConstraintUsage[iLangTerm].argvIndex = idx++;
+ pIdxInfo->aConstraintUsage[iLangTerm].omit = 1;
+ }
+ if( iPlan&4 ){
+ pIdxInfo->aConstraintUsage[iTopTerm].argvIndex = idx++;
+ pIdxInfo->aConstraintUsage[iTopTerm].omit = 1;
+ }
+ if( iPlan&8 ){
+ pIdxInfo->aConstraintUsage[iScopeTerm].argvIndex = idx++;
+ pIdxInfo->aConstraintUsage[iScopeTerm].omit = 1;
+ }
+ pIdxInfo->estimatedCost = (double)10000;
+ }else{
+ pIdxInfo->idxNum = 0;
+ pIdxInfo->estimatedCost = (double)10000000;
+ }
+ return SQLITE_OK;
+}
+
+/*
+** Open a new fuzzy-search cursor.
+*/
+static int spellfix1Open(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+ spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+ spellfix1_cursor *pCur;
+ pCur = sqlite3_malloc( sizeof(*pCur) );
+ if( pCur==0 ) return SQLITE_NOMEM;
+ memset(pCur, 0, sizeof(*pCur));
+ pCur->pVTab = p;
+ *ppCursor = &pCur->base;
+ return SQLITE_OK;
+}
+
+/*
+** Adjust a distance measurement by the words rank in order to show
+** preference to common words.
+*/
+static int spellfix1Score(int iDistance, int iRank){
+ int iLog2;
+ for(iLog2=0; iRank>0; iLog2++, iRank>>=1){}
+ return iDistance + 32 - iLog2;
+}
+
+/*
+** Compare two spellfix1_row objects for sorting purposes in qsort() such
+** that they sort in order of increasing distance.
+*/
+static int spellfix1RowCompare(const void *A, const void *B){
+ const struct spellfix1_row *a = (const struct spellfix1_row*)A;
+ const struct spellfix1_row *b = (const struct spellfix1_row*)B;
+ return a->iScore - b->iScore;
+}
+
+/*
+** This version of the xFilter method work if the MATCH term is present
+** and we are doing a scan.
+*/
+static int spellfix1FilterForMatch(
+ spellfix1_cursor *pCur,
+ int idxNum,
+ int argc,
+ sqlite3_value **argv
+){
+ const unsigned char *zPatternIn;
+ char *zPattern;
+ int nPattern;
+ char *zClass;
+ int nClass;
+ int iLimit = 20;
+ int iScope = 4;
+ int iLang = 0;
+ char *zSql;
+ int rc;
+ sqlite3_stmt *pStmt;
+ int idx = 1;
+ spellfix1_vtab *p = pCur->pVTab;
+
+ if( idxNum&2 ){
+ iLang = sqlite3_value_int(argv[idx++]);
+ }
+ if( idxNum&4 ){
+ iLimit = sqlite3_value_int(argv[idx++]);
+ if( iLimit<1 ) iLimit = 1;
+ }
+ if( idxNum&8 ){
+ iScope = sqlite3_value_int(argv[idx++]);
+ if( iScope<1 ) iScope = 1;
+ }
+ spellfix1ResetCursor(pCur, iLimit);
+ zPatternIn = sqlite3_value_text(argv[0]);
+ if( zPatternIn==0 ) return SQLITE_OK;
+ zPattern = (char*)transliterate(zPatternIn, sqlite3_value_bytes(argv[0]));
+ if( zPattern==0 ) return SQLITE_NOMEM;
+ nPattern = strlen(zPattern);
+ if( zPattern[nPattern-1]=='*' ) nPattern--;
+ if( nPattern<iScope ) iScope = nPattern;
+ zClass = (char*)characterClassString((unsigned char*)zPattern,
+ strlen(zPattern));
+ nClass = strlen(zClass);
+ if( nClass>iScope ){
+ zClass[iScope] = 0;
+ nClass = iScope;
+ }
+ zSql = sqlite3_mprintf(
+ "SELECT id, word, rank, k1"
+ " FROM \"%w\".\"%w_vocab\""
+ " WHERE langid=%d AND k2 GLOB '%q*'",
+ p->zDbName, p->zTableName, iLang, zClass
+ );
+ rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+ sqlite3_free(zSql);
+ if( rc==SQLITE_OK ){
+ const char *zK1;
+ int iDist;
+ int iRank;
+ int iScore;
+ int iWorst = 999999999;
+ int idx;
+ int idxWorst;
+ int i;
+
+ while( sqlite3_step(pStmt)==SQLITE_ROW ){
+ zK1 = (const char*)sqlite3_column_text(pStmt, 3);
+ if( zK1==0 ) continue;
+ pCur->nSearch++;
+ iRank = sqlite3_column_int(pStmt, 2);
+ iDist = editdist(zPattern, zK1);
+ iScore = spellfix1Score(iDist,iRank);
+ if( pCur->nRow<pCur->nAlloc ){
+ idx = pCur->nRow;
+ }else if( iScore<iWorst ){
+ idx = idxWorst;
+ sqlite3_free(pCur->a[idx].zWord);
+ }else{
+ continue;
+ }
+ pCur->a[idx].zWord = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 1));
+ pCur->a[idx].iRowid = sqlite3_column_int64(pStmt, 0);
+ pCur->a[idx].iRank = iRank;
+ pCur->a[idx].iDistance = iDist;
+ pCur->a[idx].iScore = iScore;
+ if( pCur->nRow<pCur->nAlloc ) pCur->nRow++;
+ if( pCur->nRow==pCur->nAlloc ){
+ iWorst = pCur->a[0].iScore;
+ idxWorst = 0;
+ for(i=1; i<pCur->nRow; i++){
+ iScore = pCur->a[i].iScore;
+ if( iWorst<iScore ){
+ iWorst = iScore;
+ idxWorst = i;
+ }
+ }
+ }
+ }
+ }
+ qsort(pCur->a, pCur->nRow, sizeof(pCur->a[0]), spellfix1RowCompare);
+ pCur->iTop = iLimit;
+ pCur->iScope = iScope;
+ sqlite3_finalize(pStmt);
+ sqlite3_free(zPattern);
+ sqlite3_free(zClass);
+ return SQLITE_OK;
+}
+
+/*
+** This version of xFilter handles a full-table scan case
+*/
+static int spellfix1FilterForFullScan(
+ spellfix1_cursor *pCur,
+ int idxNum,
+ int argc,
+ sqlite3_value **argv
+){
+ spellfix1ResetCursor(pCur, 0);
+ return SQLITE_OK;
+}
+
+
+/*
+** Called to "rewind" a cursor back to the beginning so that
+** it starts its output over again. Always called at least once
+** prior to any spellfix1Column, spellfix1Rowid, or spellfix1Eof call.
+*/
+static int spellfix1Filter(
+ sqlite3_vtab_cursor *cur,
+ int idxNum, const char *idxStr,
+ int argc, sqlite3_value **argv
+){
+ spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+ int rc;
+ if( idxNum & 1 ){
+ rc = spellfix1FilterForMatch(pCur, idxNum, argc, argv);
+ }else{
+ rc = spellfix1FilterForFullScan(pCur, idxNum, argc, argv);
+ }
+ return rc;
+}
+
+
+/*
+** Advance a cursor to its next row of output
+*/
+static int spellfix1Next(sqlite3_vtab_cursor *cur){
+ spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+ if( pCur->iRow < pCur->nRow ) pCur->iRow++;
+ return SQLITE_OK;
+}
+
+/*
+** Return TRUE if we are at the end-of-file
+*/
+static int spellfix1Eof(sqlite3_vtab_cursor *cur){
+ spellfix1_cursor *pCur = (spellfix1_cursor *)cur;
+ return pCur->iRow>=pCur->nRow;
+}
+
+/*
+** Return columns from the current row.
+*/
+static int spellfix1Column(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+ spellfix1_cursor *pCur = (spellfix1_cursor*)cur;
+ switch( i ){
+ case 0: {
+ sqlite3_result_text(ctx, pCur->a[pCur->iRow].zWord, -1, SQLITE_STATIC);
+ break;
+ }
+ case 1: {
+ sqlite3_result_int(ctx, pCur->a[pCur->iRow].iRank);
+ break;
+ }
+ case 2: {
+ sqlite3_result_int(ctx, pCur->a[pCur->iRow].iDistance);
+ break;
+ }
+ case 3: {
+ sqlite3_result_int(ctx, pCur->iLang);
+ break;
+ }
+ case 4: {
+ sqlite3_result_int(ctx, pCur->a[pCur->iRow].iScore);
+ break;
+ }
+ case 5: {
+ sqlite3_result_int(ctx, pCur->iTop);
+ break;
+ }
+ case 6: {
+ sqlite3_result_int(ctx, pCur->iScope);
+ break;
+ }
+ case 7: {
+ sqlite3_result_int(ctx, pCur->nSearch);
+ break;
+ }
+ default: {
+ sqlite3_result_null(ctx);
+ break;
+ }
+ }
+ return SQLITE_OK;
+}
+
+/*
+** The rowid.
+*/
+static int spellfix1Rowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+ spellfix1_cursor *pCur = (spellfix1_cursor*)cur;
+ *pRowid = pCur->a[pCur->iRow].iRowid;
+ return SQLITE_OK;
+}
+
+/*
+** The xUpdate() method.
+*/
+static int spellfix1Update(
+ sqlite3_vtab *pVTab,
+ int argc,
+ sqlite3_value **argv,
+ sqlite_int64 *pRowid
+){
+ int rc = SQLITE_OK;
+ sqlite3_int64 rowid, newRowid;
+ spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+ sqlite3 *db = p->db;
+
+ if( argc==1 ){
+ /* A delete operation on the rowid given by argv[0] */
+ rowid = *pRowid = sqlite3_value_int64(argv[0]);
+ spellfix1DbExec(&rc, db, "DELETE FROM \"%w\".\"%w_vocab\" "
+ " WHERE id=%lld",
+ p->zDbName, p->zTableName, rowid);
+ }else{
+ const unsigned char *zWord = sqlite3_value_text(argv[2]);
+ int nWord = sqlite3_value_bytes(argv[2]);
+ int iLang = sqlite3_value_int(argv[5]);
+ int iRank = sqlite3_value_int(argv[3]);
+ const unsigned char *zSoundslike = sqlite3_value_text(argv[10]);
+ int nSoundslike = sqlite3_value_bytes(argv[10]);
+ char *zK1, *zK2;
+ int i;
+ char c;
+
+ if( zWord==0 ){
+ pVTab->zErrMsg = sqlite3_mprintf("%w.word may not be NULL",
+ p->zTableName);
+ return SQLITE_CONSTRAINT;
+ }
+ if( iRank<1 ) iRank = 1;
+ if( zSoundslike ){
+ zK1 = (char*)transliterate(zSoundslike, nSoundslike);
+ }else{
+ zK1 = (char*)transliterate(zWord, nWord);
+ }
+ if( zK1==0 ) return SQLITE_NOMEM;
+ for(i=0; (c = zK1[i])!=0; i++){
+ if( c>='A' && c<='Z' ) zK1[i] += 'a' - 'A';
+ }
+ zK2 = (char*)characterClassString((const unsigned char*)zK1, i);
+ if( zK2==0 ){
+ sqlite3_free(zK1);
+ return SQLITE_NOMEM;
+ }
+ if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
+ spellfix1DbExec(&rc, db,
+ "INSERT INTO \"%w\".\"%w_vocab\"(rank,langid,word,k1,k2) "
+ "VALUES(%d,%d,%Q,%Q,%Q)",
+ p->zDbName, p->zTableName,
+ iRank, iLang, zWord, zK1, zK2
+ );
+ *pRowid = sqlite3_last_insert_rowid(db);
+ }else{
+ rowid = sqlite3_value_int64(argv[0]);
+ newRowid = *pRowid = sqlite3_value_int64(argv[1]);
+ spellfix1DbExec(&rc, db,
+ "UPDATE \"%w\".\"%w_vocab\" SET id=%lld, rank=%d, lang=%d,"
+ " word=%Q, rank=%d, k1=%Q, k2=%Q WHERE id=%lld",
+ p->zDbName, p->zTableName, newRowid, iRank, iLang,
+ zWord, zK1, zK2, rowid
+ );
+ }
+ sqlite3_free(zK1);
+ sqlite3_free(zK2);
+ }
+ return rc;
+}
+
+/*
+** Rename the spellfix1 table.
+*/
+static int spellfix1Rename(sqlite3_vtab *pVTab, const char *zNew){
+ spellfix1_vtab *p = (spellfix1_vtab*)pVTab;
+ sqlite3 *db = p->db;
+ int rc = SQLITE_OK;
+ char *zNewName = sqlite3_mprintf("%s", zNew);
+ if( zNewName==0 ){
+ return SQLITE_NOMEM;
+ }
+ spellfix1DbExec(&rc, db,
+ "ALTER TABLE \"%w\".\"%w_vocab\" RENAME TO \"%w_vocab\"",
+ p->zDbName, p->zTableName, zNewName
+ );
+ if( rc==SQLITE_OK ){
+ sqlite3_free(p->zTableName);
+ p->zTableName = zNewName;
+ }
+ return rc;
+}
+
+
+/*
+** A virtual table module that provides fuzzy search.
+*/
+static sqlite3_module spellfix1Module = {
+ 0, /* iVersion */
+ spellfix1Create, /* xCreate - handle CREATE VIRTUAL TABLE */
+ spellfix1Connect, /* xConnect - reconnected to an existing table */
+ spellfix1BestIndex, /* xBestIndex - figure out how to do a query */
+ spellfix1Disconnect, /* xDisconnect - close a connection */
+ spellfix1Destroy, /* xDestroy - handle DROP TABLE */
+ spellfix1Open, /* xOpen - open a cursor */
+ spellfix1Close, /* xClose - close a cursor */
+ spellfix1Filter, /* xFilter - configure scan constraints */
+ spellfix1Next, /* xNext - advance a cursor */
+ spellfix1Eof, /* xEof - check for end of scan */
+ spellfix1Column, /* xColumn - read data */
+ spellfix1Rowid, /* xRowid - read data */
+ spellfix1Update, /* xUpdate */
+ 0, /* xBegin */
+ 0, /* xSync */
+ 0, /* xCommit */
+ 0, /* xRollback */
+ 0, /* xFindMethod */
+ spellfix1Rename, /* xRename */
+};
+
+/*
+** Register the various functions and the virtual table.
+*/
+static int spellfix1Register(sqlite3 *db){
+ int nErr = 0;
+ int i;
+ nErr += sqlite3_create_function(db, "spellfix1_translit", 1, SQLITE_UTF8, 0,
+ transliterateSqlFunc, 0, 0);
+ nErr += sqlite3_create_function(db, "spellfix1_editdist", 2, SQLITE_UTF8, 0,
+ editdistSqlFunc, 0, 0);
+ nErr += sqlite3_create_function(db, "spellfix1_charclass", 1, SQLITE_UTF8, 0,
+ characterClassSqlFunc, 0, 0);
+ nErr += sqlite3_create_function(db, "spellfix1_scriptcode", 1, SQLITE_UTF8, 0,
+ scriptCodeSqlFunc, 0, 0);
+ nErr += sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0);
+
+ /* Verify sanity of the translit[] table */
+ for(i=0; i<sizeof(translit)/sizeof(translit[0])-1; i++){
+ assert( translit[i].cFrom<translit[i+1].cFrom );
+ }
+
+ return nErr ? SQLITE_ERROR : SQLITE_OK;
+}
+
+#if SQLITE_CORE || defined(SQLITE_TEST)
+/*
+** Register the spellfix1 virtual table and its associated functions.
+*/
+int sqlite3Spellfix1Register(sqlite3 *db){
+ return spellfix1Register(db);
+}
+#endif
+
+
+#if !SQLITE_CORE
+/*
+** Extension load function.
+*/
+int sqlite3_extension_init(
+ sqlite3 *db,
+ char **pzErrMsg,
+ const sqlite3_api_routines *pApi
+){
+ SQLITE_EXTENSION_INIT2(pApi);
+ return spellfix1Register(db);
+}
+#endif /* !SQLITE_CORE */
projects / thirdparty / sqlite.git / commitdiff
