SQLite

  $(TOP)/src/test_backup.c \
  $(TOP)/src/test_btree.c \
  $(TOP)/src/test_config.c \
  $(TOP)/src/test_demovfs.c \
  $(TOP)/src/test_devsym.c \
  $(TOP)/src/test_fs.c \
  $(TOP)/src/test_func.c \

  $(TOP)/src/test_hexio.c \
  $(TOP)/src/test_init.c \
  $(TOP)/src/test_intarray.c \
  $(TOP)/src/test_journal.c \
  $(TOP)/src/test_malloc.c \
  $(TOP)/src/test_multiplex.c \
  $(TOP)/src/test_mutex.c \
  $(TOP)/src/test_onefile.c \
  $(TOP)/src/test_osinst.c \
  $(TOP)/src/test_pcache.c \
  $(TOP)/src/test_quota.c \

  $(TOP)/src/test_rtree.c \
  $(TOP)/src/test_schema.c \
  $(TOP)/src/test_server.c \
  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_stat.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \

  $(TOP)/src/test_wsd.c       \
  $(TOP)/ext/fts3/fts3_term.c \
  $(TOP)/ext/fts3/fts3_test.c  \
  $(TOP)/ext/session/test_session.c

# Statically linked extensions
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \
  $(TOP)/ext/misc/wholenumber.c

# Source code to the library files needed by the test fixture
#
TESTSRC2 = \
  $(TOP)/src/attach.c \
  $(TOP)/src/backup.c \
  $(TOP)/src/bitvec.c \
  $(TOP)/src/btree.c \

  $(TOP)\src\test_backup.c \
  $(TOP)\src\test_btree.c \
  $(TOP)\src\test_config.c \
  $(TOP)\src\test_demovfs.c \
  $(TOP)\src\test_devsym.c \
  $(TOP)\src\test_fs.c \
  $(TOP)\src\test_func.c \

  $(TOP)\src\test_hexio.c \
  $(TOP)\src\test_init.c \
  $(TOP)\src\test_intarray.c \
  $(TOP)\src\test_journal.c \
  $(TOP)\src\test_malloc.c \
  $(TOP)\src\test_multiplex.c \
  $(TOP)\src\test_mutex.c \
  $(TOP)\src\test_onefile.c \
  $(TOP)\src\test_osinst.c \
  $(TOP)\src\test_pcache.c \
  $(TOP)\src\test_quota.c \

  $(TOP)\src\test_rtree.c \
  $(TOP)\src\test_schema.c \
  $(TOP)\src\test_server.c \
  $(TOP)\src\test_superlock.c \
  $(TOP)\src\test_syscall.c \
  $(TOP)\src\test_stat.c \
  $(TOP)\src\test_tclvar.c \
  $(TOP)\src\test_thread.c \
  $(TOP)\src\test_vfs.c \

  $(TOP)\src\test_wsd.c \
  $(TOP)\ext\fts3\fts3_term.c \
  $(TOP)\ext\fts3\fts3_test.c \
  $(TOP)\ext\session\test_session.c

# Statically linked extensions
#
TESTEXT = \
  $(TOP)\ext\misc\amatch.c \
  $(TOP)\ext\misc\closure.c \
  $(TOP)\ext\misc\fuzzer.c \
  $(TOP)\ext\misc\ieee754.c \
  $(TOP)\ext\misc\nextchar.c \
  $(TOP)\ext\misc\regexp.c \
  $(TOP)\ext\misc\spellfix.c \
  $(TOP)\ext\misc\wholenumber.c


# Source code to the library files needed by the test fixture
# (non-amalgamation)
#
TESTSRC2 = \
  $(TOP)\src\attach.c \
  $(TOP)\src\backup.c \

# fixture.  Otherwise link against libsqlite3.lib.  (This distinction is
# necessary because the test fixture requires non-API symbols which are
# hidden when the library is built via the amalgamation).
#
TESTFIXTURE_FLAGS = -DTCLSH=1 -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERVER=1 -DSQLITE_PRIVATE="" -DSQLITE_CORE

TESTFIXTURE_SRC0 = $(TESTEXT) $(TESTSRC2) libsqlite3.lib
TESTFIXTURE_SRC1 = $(TESTEXT) $(TESTSRC3) sqlite3.c
!IF $(USE_AMALGAMATION)==0
TESTFIXTURE_SRC = $(TESTSRC) $(TOP)\src\tclsqlite.c $(TESTFIXTURE_SRC0)
!ELSE
TESTFIXTURE_SRC = $(TESTSRC) $(TOP)\src\tclsqlite.c $(TESTFIXTURE_SRC1)
!ENDIF

testfixture.exe:	$(TESTFIXTURE_SRC) $(LIBRESOBJS) $(HDR)

    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }

    pCsr->iLangid = 0;
    if( nVal==2 ) pCsr->iLangid = sqlite3_value_int(apVal[1]);

    assert( p->base.zErrMsg==0 );
    rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
        p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr, 
        &p->base.zErrMsg
    );
    if( rc!=SQLITE_OK ){




      return rc;
    }

    rc = sqlite3Fts3ReadLock(p);
    if( rc!=SQLITE_OK ) return rc;

    rc = fts3EvalStart(pCsr);

void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
  const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,
  char **, int, int, int, const char *, int, Fts3Expr **, char **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
int sqlite3Fts3InitTerm(sqlite3 *db);
#endif

        if( !pNot ){
          sqlite3Fts3ExprFree(p);
          rc = SQLITE_NOMEM;
          goto exprparse_out;
        }
        pNot->eType = FTSQUERY_NOT;
        pNot->pRight = p;
        p->pParent = pNot;
        if( pNotBranch ){
          pNot->pLeft = pNotBranch;
          pNotBranch->pParent = pNot;
        }
        pNotBranch = pNot;
        p = pPrev;
      }else{
        int eType = p->eType;
        isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);

        rc = SQLITE_ERROR;
      }else{
        Fts3Expr *pIter = pNotBranch;
        while( pIter->pLeft ){
          pIter = pIter->pLeft;
        }
        pIter->pLeft = pRet;
        pRet->pParent = pIter;
        pRet = pNotBranch;
      }
    }
  }
  *pnConsumed = n - nIn;

exprparse_out:
  if( rc!=SQLITE_OK ){
    sqlite3Fts3ExprFree(pRet);
    sqlite3Fts3ExprFree(pNotBranch);
    pRet = 0;
  }
  *ppExpr = pRet;
  return rc;
}

/*
** Return SQLITE_ERROR if the maximum depth of the expression tree passed 
** as the only argument is more than nMaxDepth.
*/
static int fts3ExprCheckDepth(Fts3Expr *p, int nMaxDepth){
  int rc = SQLITE_OK;
  if( p ){
    if( nMaxDepth<0 ){ 
      rc = SQLITE_TOOBIG;
    }else{
      rc = fts3ExprCheckDepth(p->pLeft, nMaxDepth-1);
      if( rc==SQLITE_OK ){
        rc = fts3ExprCheckDepth(p->pRight, nMaxDepth-1);
      }
    }
  }
  return rc;
}

/*
** This function attempts to transform the expression tree at (*pp) to
** an equivalent but more balanced form. The tree is modified in place.
** If successful, SQLITE_OK is returned and (*pp) set to point to the 
** new root expression node. 
**
** nMaxDepth is the maximum allowable depth of the balanced sub-tree.
**
** Otherwise, if an error occurs, an SQLite error code is returned and 
** expression (*pp) freed.
*/
static int fts3ExprBalance(Fts3Expr **pp, int nMaxDepth){
  int rc = SQLITE_OK;             /* Return code */
  Fts3Expr *pRoot = *pp;          /* Initial root node */
  Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */
  int eType = pRoot->eType;       /* Type of node in this tree */

  if( nMaxDepth==0 ){
    rc = SQLITE_ERROR;
  }

  if( rc==SQLITE_OK && (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){
    Fts3Expr **apLeaf;
    apLeaf = (Fts3Expr **)sqlite3_malloc(sizeof(Fts3Expr *) * nMaxDepth);
    if( 0==apLeaf ){
      rc = SQLITE_NOMEM;
    }else{
      memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);
    }

    if( rc==SQLITE_OK ){
      int i;
      Fts3Expr *p;

      /* Set $p to point to the left-most leaf in the tree of eType nodes. */
      for(p=pRoot; p->eType==eType; p=p->pLeft){
        assert( p->pParent==0 || p->pParent->pLeft==p );
        assert( p->pLeft && p->pRight );
      }

      /* This loop runs once for each leaf in the tree of eType nodes. */
      while( 1 ){
        int iLvl;
        Fts3Expr *pParent = p->pParent;     /* Current parent of p */

        assert( pParent==0 || pParent->pLeft==p );
        p->pParent = 0;
        if( pParent ){
          pParent->pLeft = 0;
        }else{
          pRoot = 0;
        }
        rc = fts3ExprBalance(&p, nMaxDepth-1);
        if( rc!=SQLITE_OK ) break;

        for(iLvl=0; p && iLvl<nMaxDepth; iLvl++){
          if( apLeaf[iLvl]==0 ){
            apLeaf[iLvl] = p;
            p = 0;
          }else{
            assert( pFree );
            pFree->pLeft = apLeaf[iLvl];
            pFree->pRight = p;
            pFree->pLeft->pParent = pFree;
            pFree->pRight->pParent = pFree;

            p = pFree;
            pFree = pFree->pParent;
            p->pParent = 0;
            apLeaf[iLvl] = 0;
          }
        }
        if( p ){
          sqlite3Fts3ExprFree(p);
          rc = SQLITE_TOOBIG;
          break;
        }

        /* If that was the last leaf node, break out of the loop */
        if( pParent==0 ) break;

        /* Set $p to point to the next leaf in the tree of eType nodes */
        for(p=pParent->pRight; p->eType==eType; p=p->pLeft);

        /* Remove pParent from the original tree. */
        assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );
        pParent->pRight->pParent = pParent->pParent;
        if( pParent->pParent ){
          pParent->pParent->pLeft = pParent->pRight;
        }else{
          assert( pParent==pRoot );
          pRoot = pParent->pRight;
        }

        /* Link pParent into the free node list. It will be used as an
        ** internal node of the new tree.  */
        pParent->pParent = pFree;
        pFree = pParent;
      }

      if( rc==SQLITE_OK ){
        p = 0;
        for(i=0; i<nMaxDepth; i++){
          if( apLeaf[i] ){
            if( p==0 ){
              p = apLeaf[i];
              p->pParent = 0;
            }else{
              pFree->pRight = p;
              pFree->pLeft = apLeaf[i];
              pFree->pLeft->pParent = pFree;
              pFree->pRight->pParent = pFree;

              p = pFree;
              pFree = pFree->pParent;
              p->pParent = 0;
            }
          }
        }
        pRoot = p;
      }else{
        /* An error occurred. Delete the contents of the apLeaf[] array 
        ** and pFree list. Everything else is cleaned up by the call to
        ** sqlite3Fts3ExprFree(pRoot) below.  */
        Fts3Expr *pDel;
        for(i=0; i<nMaxDepth; i++){
          sqlite3Fts3ExprFree(apLeaf[i]);
        }
        while( (pDel=pFree)!=0 ){
          pFree = pDel->pParent;
          sqlite3_free(pDel);
        }
      }

      assert( pFree==0 );
      sqlite3_free( apLeaf );
    }
  }

  if( rc!=SQLITE_OK ){
    sqlite3Fts3ExprFree(pRoot);
    pRoot = 0;
  }
  *pp = pRoot;
  return rc;
}

/*
** This function is similar to sqlite3Fts3ExprParse(), with the following
** differences:
**
**   1. It does not do expression rebalancing.
**   2. It does not check that the expression does not exceed the 
**      maximum allowable depth.
**   3. Even if it fails, *ppExpr may still be set to point to an 
**      expression tree. It should be deleted using sqlite3Fts3ExprFree()
**      in this case.
*/
static int fts3ExprParseUnbalanced(
  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
  int iLangid,                        /* Language id for tokenizer */
  char **azCol,                       /* Array of column names for fts3 table */
  int bFts4,                          /* True to allow FTS4-only syntax */
  int nCol,                           /* Number of entries in azCol[] */
  int iDefaultCol,                    /* Default column to query */
  const char *z, int n,               /* Text of MATCH query */
  Fts3Expr **ppExpr                   /* OUT: Parsed query structure */
){
  int nParsed;
  int rc;
  ParseContext sParse;

  memset(&sParse, 0, sizeof(ParseContext));
  sParse.pTokenizer = pTokenizer;
  sParse.iLangid = iLangid;
  sParse.azCol = (const char **)azCol;
  sParse.nCol = nCol;
  sParse.iDefaultCol = iDefaultCol;
  sParse.bFts4 = bFts4;
  if( z==0 ){
    *ppExpr = 0;
    return SQLITE_OK;
  }
  if( n<0 ){
    n = (int)strlen(z);
  }
  rc = fts3ExprParse(&sParse, z, n, ppExpr, &nParsed);
  assert( rc==SQLITE_OK || *ppExpr==0 );

  /* Check for mismatched parenthesis */
  if( rc==SQLITE_OK && sParse.nNest ){
    rc = SQLITE_ERROR;
  }
  
  return rc;
}

/*
** Parameters z and n contain a pointer to and length of a buffer containing
** an fts3 query expression, respectively. This function attempts to parse the
** query expression and create a tree of Fts3Expr structures representing the
** parsed expression. If successful, *ppExpr is set to point to the head
** of the parsed expression tree and SQLITE_OK is returned. If an error

  sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */
  int iLangid,                        /* Language id for tokenizer */
  char **azCol,                       /* Array of column names for fts3 table */
  int bFts4,                          /* True to allow FTS4-only syntax */
  int nCol,                           /* Number of entries in azCol[] */
  int iDefaultCol,                    /* Default column to query */
  const char *z, int n,               /* Text of MATCH query */
  Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */
  char **pzErr                        /* OUT: Error message (sqlite3_malloc) */
){
  static const int MAX_EXPR_DEPTH = 12;
  int rc = fts3ExprParseUnbalanced(

      pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr
  );
  


  /* Rebalance the expression. And check that its depth does not exceed
  ** MAX_EXPR_DEPTH.  */



  if( rc==SQLITE_OK && *ppExpr ){
    rc = fts3ExprBalance(ppExpr, MAX_EXPR_DEPTH);
    if( rc==SQLITE_OK ){
      rc = fts3ExprCheckDepth(*ppExpr, MAX_EXPR_DEPTH);
    }


  }



  if( rc!=SQLITE_OK ){

    sqlite3Fts3ExprFree(*ppExpr);
    *ppExpr = 0;
    if( rc==SQLITE_TOOBIG ){
      *pzErr = sqlite3_mprintf(
          "FTS expression tree is too large (maximum depth %d)", MAX_EXPR_DEPTH
      );
      rc = SQLITE_ERROR;
    }else if( rc==SQLITE_ERROR ){
      *pzErr = sqlite3_mprintf("malformed MATCH expression: [%s]", z);
    }
  }

  return rc;
}

/*
** Free a single node of an expression tree.
*/
static void fts3FreeExprNode(Fts3Expr *p){
  assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );
  sqlite3Fts3EvalPhraseCleanup(p->pPhrase);
  sqlite3_free(p->aMI);
  sqlite3_free(p);
}

/*
** Free a parsed fts3 query expression allocated by sqlite3Fts3ExprParse().
**
** This function would be simpler if it recursively called itself. But
** that would mean passing a sufficiently large expression to ExprParse()
** could cause a stack overflow.
*/
void sqlite3Fts3ExprFree(Fts3Expr *pDel){
  Fts3Expr *p;
  assert( pDel==0 || pDel->pParent==0 );
  for(p=pDel; p && (p->pLeft||p->pRight); p=(p->pLeft ? p->pLeft : p->pRight)){
    assert( p->pParent==0 || p==p->pParent->pRight || p==p->pParent->pLeft );
  }
  while( p ){

    Fts3Expr *pParent = p->pParent;
    fts3FreeExprNode(p);
    if( pParent && p==pParent->pLeft && pParent->pRight ){
      p = pParent->pRight;

      while( p && (p->pLeft || p->pRight) ){
        assert( p==p->pParent->pRight || p==p->pParent->pLeft );
        p = (p->pLeft ? p->pLeft : p->pRight);
      }
    }else{
      p = pParent;
    }
  }
}

/****************************************************************************
*****************************************************************************
** Everything after this point is just test code.
*/

** sqlite3_free() to release the memory. If an OOM condition is encountered,
** NULL is returned.
**
** If the second argument is not NULL, then its contents are prepended to 
** the returned expression text and then freed using sqlite3_free().
*/
static char *exprToString(Fts3Expr *pExpr, char *zBuf){
  if( pExpr==0 ){
    return sqlite3_mprintf("");
  }
  switch( pExpr->eType ){
    case FTSQUERY_PHRASE: {
      Fts3Phrase *pPhrase = pExpr->pPhrase;
      int i;
      zBuf = sqlite3_mprintf(
          "%zPHRASE %d 0", zBuf, pPhrase->iColumn);
      for(i=0; zBuf && i<pPhrase->nToken; i++){

    sqlite3_result_error_nomem(context);
    goto exprtest_out;
  }
  for(ii=0; ii<nCol; ii++){
    azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);
  }

  if( sqlite3_user_data(context) ){
    char *zDummy = 0;
    rc = sqlite3Fts3ExprParse(
        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr, &zDummy
    );
    assert( rc==SQLITE_OK || pExpr==0 );
    sqlite3_free(zDummy);
  }else{
    rc = fts3ExprParseUnbalanced(
        pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr
    );
  }

  if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM ){
    sqlite3Fts3ExprFree(pExpr);
    sqlite3_result_error(context, "Error parsing expression", -1);
  }else if( rc==SQLITE_NOMEM || !(zBuf = exprToString(pExpr, 0)) ){
    sqlite3_result_error_nomem(context);
  }else{
    sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
    sqlite3_free(zBuf);
  }

}

/*
** Register the query expression parser test function fts3_exprtest() 
** with database connection db. 
*/
int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
  int rc = sqlite3_create_function(
      db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
  );
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "fts3_exprtest_rebalance", 
        -1, SQLITE_UTF8, (void *)1, fts3ExprTest, 0, 0
    );
  }
  return rc;
}

#endif
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

/*
** 2013-03-14
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code for a demonstration virtual table that finds
** "approximate matches" - strings from a finite set that are nearly the
** same as a single input string.  The virtual table is called "amatch".
**
** A amatch virtual table is created like this:
**
**     CREATE VIRTUAL TABLE f USING approximate_match(
**        vocabulary_table=<tablename>,      -- V
**        vocabulary_word=<columnname>,      -- W
**        vocabulary_language=<columnname>,  -- L
**        edit_distances=<edit-cost-table>
**     );
**
** When it is created, the new amatch table must be supplied with the
** the name of a table V and columns V.W and V.L such that 
**
**     SELECT W FROM V WHERE L=$language
**
** returns the allowed vocabulary for the match.  If the "vocabulary_language"
** or L columnname is left unspecified or is an empty string, then no
** filtering of the vocabulary by language is performed. 
**
** For efficiency, it is essential that the vocabulary table be indexed:
**
**     CREATE vocab_index ON V(W)
**
** A separate edit-cost-table provides scoring information that defines 
** what it means for one string to be "close" to another.
**
** The edit-cost-table must contain exactly four columns (more precisely,
** the statement "SELECT * FROM <edit-cost-table>" must return records
** that consist of four columns). It does not matter what the columns are
** named. 
**
** Each row in the edit-cost-table represents a single character
** transformation going from user input to the vocabulary. The leftmost 
** column of the row (column 0) contains an integer identifier of the
** language to which the transformation rule belongs (see "MULTIPLE LANGUAGES"
** below). The second column of the row (column 1) contains the input
** character or characters - the characters of user input. The third 
** column contains characters as they appear in the vocabulary table.
** And the fourth column contains the integer cost of making the
** transformation. For example:
**
**    CREATE TABLE f_data(iLang, cFrom, cTo, Cost);
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '', 'a', 100);
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, 'b', '', 87);
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, 'o', 'oe', 38);
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, 'oe', 'o', 40);
**
** The first row inserted into the edit-cost-table by the SQL script
** above indicates that the cost of having an extra 'a' in the vocabulary
** table that is missing in the user input 100.  (All costs are integers.
** Overall cost must not exceed 16777216.)  The second INSERT statement 
** creates a rule saying that the cost of having a single letter 'b' in
** user input which is missing in the vocabulary table is 87.  The third
** INSERT statement mean that the cost of matching an 'o' in user input 
** against an 'oe' in the vocabulary table is 38.  And so forth.
**
** The following rules are special:
**
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '?', '', 97);
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '', '?', 98);
**    INSERT INTO f_data(iLang, cFrom, cTo, Cost) VALUES(0, '?', '?', 99);
**
** The '?' to '' rule is the cost of having any single character in the input
** that is not found in the vocabular.  The '' to '?' rule is the cost of
** having a character in the vocabulary table that is missing from input.
** And the '?' to '?' rule is the cost of doing an arbitrary character
** substitution.  These three generic rules apply across all languages.
** In other words, the iLang field is ignored for the generic substitution
** rules.  If more than one cost is given for a generic substitution rule,
** then the lowest cost is used.
**
** Once it has been created, the amatch virtual table can be queried
** as follows:
**
**    SELECT word, distance FROM f
**     WHERE word MATCH 'abcdefg'
**       AND distance<200;
**
** This query outputs the strings contained in the T(F) field that
** are close to "abcdefg" and in order of increasing distance.  No string
** is output more than once.  If there are multiple ways to transform the
** target string ("abcdefg") into a string in the vocabulary table then
** the lowest cost transform is the one that is returned.  In this example,
** the search is limited to strings with a total distance of less than 200.
**
** For efficiency, it is important to put tight bounds on the distance.
** The time and memory space needed to perform this query is exponential
** in the maximum distance.  A good rule of thumb is to limit the distance
** to no more than 1.5 or 2 times the maximum cost of any rule in the
** edit-cost-table.
**
** The amatch is a read-only table.  Any attempt to DELETE, INSERT, or
** UPDATE on a amatch table will throw an error.
**
** It is important to put some kind of a limit on the amatch output.  This
** can be either in the form of a LIMIT clause at the end of the query,
** or better, a "distance<NNN" constraint where NNN is some number.  The
** running time and memory requirement is exponential in the value of NNN 
** so you want to make sure that NNN is not too big.  A value of NNN that
** is about twice the average transformation cost seems to give good results.
**
** The amatch table can be useful for tasks such as spelling correction.
** Suppose all allowed words are in table vocabulary(w).  Then one would create
** an amatch virtual table like this:
**
**   CREATE VIRTUAL TABLE ex1 USING amatch(
**       vocabtable=vocabulary,
**       vocabcolumn=w,
**       edit_distances=ec1
**   );
**
** Then given an input word $word, look up close spellings this way:
**
**   SELECT word, distance FROM ex1
**    WHERE word MATCH $word AND distance<200;
**
** MULTIPLE LANGUAGES
**
** Normally, the "iLang" value associated with all character transformations
** in the edit-cost-table is zero. However, if required, the amatch 
** virtual table allows multiple languages to be defined. Each query uses 
** only a single iLang value.   This allows, for example, a single 
** amatch table to support multiple languages.
**
** By default, only the rules with iLang=0 are used. To specify an 
** alternative language, a "language = ?" expression must be added to the
** WHERE clause of a SELECT, where ? is the integer identifier of the desired 
** language. For example:
**
**   SELECT word, distance FROM ex1
**    WHERE word MATCH $word
**      AND distance<=200
**      AND language=1 -- Specify use language 1 instead of 0
**
** If no "language = ?" constraint is specified in the WHERE clause, language
** 0 is used.
**
** LIMITS
**
** The maximum language number is 2147483647.  The maximum length of either
** of the strings in the second or third column of the amatch data table
** is 50 bytes.  The maximum cost on a rule is 1000.
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <ctype.h>

/*
** Forward declaration of objects used by this implementation
*/
typedef struct amatch_vtab amatch_vtab;
typedef struct amatch_cursor amatch_cursor;
typedef struct amatch_rule amatch_rule;
typedef struct amatch_word amatch_word;
typedef struct amatch_avl amatch_avl;


/*****************************************************************************
** AVL Tree implementation
*/
/*
** Objects that want to be members of the AVL tree should embedded an
** instance of this structure.
*/
struct amatch_avl {
  amatch_word *pWord;   /* Points to the object being stored in the tree */
  char *zKey;           /* Key.  zero-terminated string.  Must be unique */
  amatch_avl *pBefore;  /* Other elements less than zKey */
  amatch_avl *pAfter;   /* Other elements greater than zKey */
  amatch_avl *pUp;      /* Parent element */
  short int height;     /* Height of this node.  Leaf==1 */
  short int imbalance;  /* Height difference between pBefore and pAfter */
};

/* Recompute the amatch_avl.height and amatch_avl.imbalance fields for p.
** Assume that the children of p have correct heights.
*/
static void amatchAvlRecomputeHeight(amatch_avl *p){
  short int hBefore = p->pBefore ? p->pBefore->height : 0;
  short int hAfter = p->pAfter ? p->pAfter->height : 0;
  p->imbalance = hBefore - hAfter;  /* -: pAfter higher.  +: pBefore higher */
  p->height = (hBefore>hAfter ? hBefore : hAfter)+1;
}

/*
**     P                B
**    / \              / \
**   B   Z    ==>     X   P
**  / \                  / \
** X   Y                Y   Z
**
*/
static amatch_avl *amatchAvlRotateBefore(amatch_avl *pP){
  amatch_avl *pB = pP->pBefore;
  amatch_avl *pY = pB->pAfter;
  pB->pUp = pP->pUp;
  pB->pAfter = pP;
  pP->pUp = pB;
  pP->pBefore = pY;
  if( pY ) pY->pUp = pP;
  amatchAvlRecomputeHeight(pP);
  amatchAvlRecomputeHeight(pB);
  return pB;
}

/*
**     P                A
**    / \              / \
**   X   A    ==>     P   Z
**      / \          / \
**     Y   Z        X   Y
**
*/
static amatch_avl *amatchAvlRotateAfter(amatch_avl *pP){
  amatch_avl *pA = pP->pAfter;
  amatch_avl *pY = pA->pBefore;
  pA->pUp = pP->pUp;
  pA->pBefore = pP;
  pP->pUp = pA;
  pP->pAfter = pY;
  if( pY ) pY->pUp = pP;
  amatchAvlRecomputeHeight(pP);
  amatchAvlRecomputeHeight(pA);
  return pA;
}

/*
** Return a pointer to the pBefore or pAfter pointer in the parent
** of p that points to p.  Or if p is the root node, return pp.
*/
static amatch_avl **amatchAvlFromPtr(amatch_avl *p, amatch_avl **pp){
  amatch_avl *pUp = p->pUp;
  if( pUp==0 ) return pp;
  if( pUp->pAfter==p ) return &pUp->pAfter;
  return &pUp->pBefore;
}

/*
** Rebalance all nodes starting with p and working up to the root.
** Return the new root.
*/
static amatch_avl *amatchAvlBalance(amatch_avl *p){
  amatch_avl *pTop = p;
  amatch_avl **pp;
  while( p ){
    amatchAvlRecomputeHeight(p);
    if( p->imbalance>=2 ){
      amatch_avl *pB = p->pBefore;
      if( pB->imbalance<0 ) p->pBefore = amatchAvlRotateAfter(pB);
      pp = amatchAvlFromPtr(p,&p);
      p = *pp = amatchAvlRotateBefore(p);
    }else if( p->imbalance<=(-2) ){
      amatch_avl *pA = p->pAfter;
      if( pA->imbalance>0 ) p->pAfter = amatchAvlRotateBefore(pA);
      pp = amatchAvlFromPtr(p,&p);
      p = *pp = amatchAvlRotateAfter(p);
    }
    pTop = p;
    p = p->pUp;
  }
  return pTop;
}

/* Search the tree rooted at p for an entry with zKey.  Return a pointer
** to the entry or return NULL.
*/
static amatch_avl *amatchAvlSearch(amatch_avl *p, const char *zKey){
  int c;
  while( p && (c = strcmp(zKey, p->zKey))!=0 ){
    p = (c<0) ? p->pBefore : p->pAfter;
  }
  return p;
}

/* Find the first node (the one with the smallest key).
*/
static amatch_avl *amatchAvlFirst(amatch_avl *p){
  if( p ) while( p->pBefore ) p = p->pBefore;
  return p;
}

#if 0 /* NOT USED */
/* Return the node with the next larger key after p.
*/
static amatch_avl *amatchAvlNext(amatch_avl *p){
  amatch_avl *pPrev = 0;
  while( p && p->pAfter==pPrev ){
    pPrev = p;
    p = p->pUp;
  }
  if( p && pPrev==0 ){
    p = amatchAvlFirst(p->pAfter);
  }
  return p;
}
#endif

#if 0 /* NOT USED */
/* Verify AVL tree integrity
*/
static int amatchAvlIntegrity(amatch_avl *pHead){
  amatch_avl *p;
  if( pHead==0 ) return 1;
  if( (p = pHead->pBefore)!=0 ){
    assert( p->pUp==pHead );
    assert( amatchAvlIntegrity(p) );
    assert( strcmp(p->zKey, pHead->zKey)<0 );
    while( p->pAfter ) p = p->pAfter;
    assert( strcmp(p->zKey, pHead->zKey)<0 );
  }
  if( (p = pHead->pAfter)!=0 ){
    assert( p->pUp==pHead );
    assert( amatchAvlIntegrity(p) );
    assert( strcmp(p->zKey, pHead->zKey)>0 );
    p = amatchAvlFirst(p);
    assert( strcmp(p->zKey, pHead->zKey)>0 );
  }
  return 1;
}
static int amatchAvlIntegrity2(amatch_avl *pHead){
  amatch_avl *p, *pNext;
  for(p=amatchAvlFirst(pHead); p; p=pNext){
    pNext = amatchAvlNext(p);
    if( pNext==0 ) break;
    assert( strcmp(p->zKey, pNext->zKey)<0 );
  }
  return 1;
}
#endif

/* Insert a new node pNew.  Return NULL on success.  If the key is not
** unique, then do not perform the insert but instead leave pNew unchanged
** and return a pointer to an existing node with the same key.
*/
static amatch_avl *amatchAvlInsert(amatch_avl **ppHead, amatch_avl *pNew){
  int c;
  amatch_avl *p = *ppHead;
  if( p==0 ){
    p = pNew;
    pNew->pUp = 0;
  }else{
    while( p ){
      c = strcmp(pNew->zKey, p->zKey);
      if( c<0 ){
        if( p->pBefore ){
          p = p->pBefore;
        }else{
          p->pBefore = pNew;
          pNew->pUp = p;
          break;
        }
      }else if( c>0 ){
        if( p->pAfter ){
          p = p->pAfter;
        }else{
          p->pAfter = pNew;
          pNew->pUp = p;
          break;
        }
      }else{
        return p;
      }
    }
  }
  pNew->pBefore = 0;
  pNew->pAfter = 0;
  pNew->height = 1;
  pNew->imbalance = 0;
  *ppHead = amatchAvlBalance(p);
  /* assert( amatchAvlIntegrity(*ppHead) ); */
  /* assert( amatchAvlIntegrity2(*ppHead) ); */
  return 0;
}

/* Remove node pOld from the tree.  pOld must be an element of the tree or
** the AVL tree will become corrupt.
*/
static void amatchAvlRemove(amatch_avl **ppHead, amatch_avl *pOld){
  amatch_avl **ppParent;
  amatch_avl *pBalance;
  /* assert( amatchAvlSearch(*ppHead, pOld->zKey)==pOld ); */
  ppParent = amatchAvlFromPtr(pOld, ppHead);
  if( pOld->pBefore==0 && pOld->pAfter==0 ){
    *ppParent = 0;
    pBalance = pOld->pUp;
  }else if( pOld->pBefore && pOld->pAfter ){
    amatch_avl *pX, *pY;
    pX = amatchAvlFirst(pOld->pAfter);
    *amatchAvlFromPtr(pX, 0) = pX->pAfter;
    if( pX->pAfter ) pX->pAfter->pUp = pX->pUp;
    pBalance = pX->pUp;
    pX->pAfter = pOld->pAfter;
    if( pX->pAfter ){
      pX->pAfter->pUp = pX;
    }else{
      assert( pBalance==pOld );
      pBalance = pX;
    }
    pX->pBefore = pY = pOld->pBefore;
    if( pY ) pY->pUp = pX;
    pX->pUp = pOld->pUp;
    *ppParent = pX;
  }else if( pOld->pBefore==0 ){
    *ppParent = pBalance = pOld->pAfter;
    pBalance->pUp = pOld->pUp;
  }else if( pOld->pAfter==0 ){
    *ppParent = pBalance = pOld->pBefore;
    pBalance->pUp = pOld->pUp;
  }
  *ppHead = amatchAvlBalance(pBalance);
  pOld->pUp = 0;
  pOld->pBefore = 0;
  pOld->pAfter = 0;
  /* assert( amatchAvlIntegrity(*ppHead) ); */
  /* assert( amatchAvlIntegrity2(*ppHead) ); */
}
/*
** End of the AVL Tree implementation
******************************************************************************/


/*
** Various types.
**
** amatch_cost is the "cost" of an edit operation.
**
** amatch_len is the length of a matching string.  
**
** amatch_langid is an ruleset identifier.
*/
typedef int amatch_cost;
typedef signed char amatch_len;
typedef int amatch_langid;

/*
** Limits
*/
#define AMATCH_MX_LENGTH          50  /* Maximum length of a rule string */
#define AMATCH_MX_LANGID  2147483647  /* Maximum rule ID */
#define AMATCH_MX_COST          1000  /* Maximum single-rule cost */

/*
** A match or partial match
*/
struct amatch_word {
  amatch_word *pNext;   /* Next on a list of all amatch_words */
  amatch_avl sCost;     /* Linkage of this node into the cost tree */
  amatch_avl sWord;     /* Linkage of this node into the word tree */
  amatch_cost rCost;    /* Cost of the match so far */
  int iSeq;             /* Sequence number */
  char zCost[10];       /* Cost key (text rendering of rCost) */
  short int nMatch;     /* Input characters matched */
  char zWord[4];        /* Text of the word.  Extra space appended as needed */
};

/*
** Each transformation rule is stored as an instance of this object.
** All rules are kept on a linked list sorted by rCost.
*/
struct amatch_rule {
  amatch_rule *pNext;      /* Next rule in order of increasing rCost */
  char *zFrom;             /* Transform from (a string from user input) */
  amatch_cost rCost;       /* Cost of this transformation */
  amatch_langid iLang;     /* The langauge to which this rule belongs */
  amatch_len nFrom, nTo;   /* Length of the zFrom and zTo strings */
  char zTo[4];             /* Tranform to V.W value (extra space appended) */
};

/* 
** A amatch virtual-table object 
*/
struct amatch_vtab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zClassName;          /* Name of this class.  Default: "amatch" */
  char *zDb;                 /* Name of database.  (ex: "main") */
  char *zSelf;               /* Name of this virtual table */
  char *zCostTab;            /* Name of edit-cost-table */
  char *zVocabTab;           /* Name of vocabulary table */
  char *zVocabWord;          /* Name of vocabulary table word column */
  char *zVocabLang;          /* Name of vocabulary table language column */
  amatch_rule *pRule;        /* All active rules in this amatch */
  amatch_cost rIns;          /* Generic insertion cost  '' -> ? */
  amatch_cost rDel;          /* Generic deletion cost  ? -> '' */
  amatch_cost rSub;          /* Generic substitution cost ? -> ? */
  sqlite3 *db;               /* The database connection */
  sqlite3_stmt *pVCheck;     /* Query to check zVocabTab */
  int nCursor;               /* Number of active cursors */
};

/* A amatch cursor object */
struct amatch_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  sqlite3_int64 iRowid;      /* The rowid of the current word */
  amatch_langid iLang;       /* Use this language ID */
  amatch_cost rLimit;        /* Maximum cost of any term */
  int nBuf;                  /* Space allocated for zBuf */
  int oomErr;                /* True following an OOM error */
  int nWord;                 /* Number of amatch_word objects */
  char *zBuf;                /* Temp-use buffer space */
  char *zInput;              /* Input word to match against */
  amatch_vtab *pVtab;        /* The virtual table this cursor belongs to */
  amatch_word *pAllWords;    /* List of all amatch_word objects */
  amatch_word *pCurrent;     /* Most recent solution */
  amatch_avl *pCost;         /* amatch_word objects keyed by iCost */
  amatch_avl *pWord;         /* amatch_word objects keyed by zWord */
};

/*
** The two input rule lists are both sorted in order of increasing
** cost.  Merge them together into a single list, sorted by cost, and
** return a pointer to the head of that list.
*/
static amatch_rule *amatchMergeRules(amatch_rule *pA, amatch_rule *pB){
  amatch_rule head;
  amatch_rule *pTail;

  pTail =  &head;
  while( pA && pB ){
    if( pA->rCost<=pB->rCost ){
      pTail->pNext = pA;
      pTail = pA;
      pA = pA->pNext;
    }else{
      pTail->pNext = pB;
      pTail = pB;
      pB = pB->pNext;
    }
  }
  if( pA==0 ){
    pTail->pNext = pB;
  }else{
    pTail->pNext = pA;
  }
  return head.pNext;
}

/*
** Statement pStmt currently points to a row in the amatch data table. This
** function allocates and populates a amatch_rule structure according to
** the content of the row.
**
** If successful, *ppRule is set to point to the new object and SQLITE_OK
** is returned. Otherwise, *ppRule is zeroed, *pzErr may be set to point
** to an error message and an SQLite error code returned.
*/
static int amatchLoadOneRule(
  amatch_vtab *p,                 /* Fuzzer virtual table handle */
  sqlite3_stmt *pStmt,            /* Base rule on statements current row */
  amatch_rule **ppRule,           /* OUT: New rule object */
  char **pzErr                    /* OUT: Error message */
){
  sqlite3_int64 iLang = sqlite3_column_int64(pStmt, 0);
  const char *zFrom = (const char *)sqlite3_column_text(pStmt, 1);
  const char *zTo = (const char *)sqlite3_column_text(pStmt, 2);
  amatch_cost rCost = sqlite3_column_int(pStmt, 3);

  int rc = SQLITE_OK;             /* Return code */
  int nFrom;                      /* Size of string zFrom, in bytes */
  int nTo;                        /* Size of string zTo, in bytes */
  amatch_rule *pRule = 0;         /* New rule object to return */

  if( zFrom==0 ) zFrom = "";
  if( zTo==0 ) zTo = "";
  nFrom = (int)strlen(zFrom);
  nTo = (int)strlen(zTo);

  /* Silently ignore null transformations */
  if( strcmp(zFrom, zTo)==0 ){
    if( zFrom[0]=='?' && zFrom[1]==0 ){
      if( p->rSub==0 || p->rSub>rCost ) p->rSub = rCost;
    }
    *ppRule = 0;
    return SQLITE_OK;
  }

  if( rCost<=0 || rCost>AMATCH_MX_COST ){
    *pzErr = sqlite3_mprintf("%s: cost must be between 1 and %d", 
        p->zClassName, AMATCH_MX_COST
    );
    rc = SQLITE_ERROR;
  }else
  if( nFrom>AMATCH_MX_LENGTH || nTo>AMATCH_MX_LENGTH ){
    *pzErr = sqlite3_mprintf("%s: maximum string length is %d", 
        p->zClassName, AMATCH_MX_LENGTH
    );
    rc = SQLITE_ERROR;    
  }else
  if( iLang<0 || iLang>AMATCH_MX_LANGID ){
    *pzErr = sqlite3_mprintf("%s: iLang must be between 0 and %d", 
        p->zClassName, AMATCH_MX_LANGID
    );
    rc = SQLITE_ERROR;    
  }else
  if( strcmp(zFrom,"")==0 && strcmp(zTo,"?")==0 ){
    if( p->rIns==0 || p->rIns>rCost ) p->rIns = rCost;
  }else
  if( strcmp(zFrom,"?")==0 && strcmp(zTo,"")==0 ){
    if( p->rDel==0 || p->rDel>rCost ) p->rDel = rCost;
  }else
  {
    pRule = sqlite3_malloc( sizeof(*pRule) + nFrom + nTo );
    if( pRule==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pRule, 0, sizeof(*pRule));
      pRule->zFrom = &pRule->zTo[nTo+1];
      pRule->nFrom = nFrom;
      memcpy(pRule->zFrom, zFrom, nFrom+1);
      memcpy(pRule->zTo, zTo, nTo+1);
      pRule->nTo = nTo;
      pRule->rCost = rCost;
      pRule->iLang = (int)iLang;
    }
  }

  *ppRule = pRule;
  return rc;
}

/*
** Free all the content in the edit-cost-table
*/
static void amatchFreeRules(amatch_vtab *p){
  while( p->pRule ){
    amatch_rule *pRule = p->pRule;
    p->pRule = pRule->pNext;
    sqlite3_free(pRule);
  }
  p->pRule = 0;
}

/*
** Load the content of the amatch data table into memory.
*/
static int amatchLoadRules(
  sqlite3 *db,                    /* Database handle */
  amatch_vtab *p,                 /* Virtual amatch table to configure */
  char **pzErr                    /* OUT: Error message */
){
  int rc = SQLITE_OK;             /* Return code */
  char *zSql;                     /* SELECT used to read from rules table */
  amatch_rule *pHead = 0;

  zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", p->zDb, p->zCostTab);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    int rc2;                      /* finalize() return code */
    sqlite3_stmt *pStmt = 0;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
    if( rc!=SQLITE_OK ){
      *pzErr = sqlite3_mprintf("%s: %s", p->zClassName, sqlite3_errmsg(db));
    }else if( sqlite3_column_count(pStmt)!=4 ){
      *pzErr = sqlite3_mprintf("%s: %s has %d columns, expected 4",
          p->zClassName, p->zCostTab, sqlite3_column_count(pStmt)
      );
      rc = SQLITE_ERROR;
    }else{
      while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
        amatch_rule *pRule = 0;
        rc = amatchLoadOneRule(p, pStmt, &pRule, pzErr);
        if( pRule ){
          pRule->pNext = pHead;
          pHead = pRule;
        }
      }
    }
    rc2 = sqlite3_finalize(pStmt);
    if( rc==SQLITE_OK ) rc = rc2;
  }
  sqlite3_free(zSql);

  /* All rules are now in a singly linked list starting at pHead. This
  ** block sorts them by cost and then sets amatch_vtab.pRule to point to 
  ** point to the head of the sorted list.
  */
  if( rc==SQLITE_OK ){
    unsigned int i;
    amatch_rule *pX;
    amatch_rule *a[15];
    for(i=0; i<sizeof(a)/sizeof(a[0]); i++) a[i] = 0;
    while( (pX = pHead)!=0 ){
      pHead = pX->pNext;
      pX->pNext = 0;
      for(i=0; a[i] && i<sizeof(a)/sizeof(a[0])-1; i++){
        pX = amatchMergeRules(a[i], pX);
        a[i] = 0;
      }
      a[i] = amatchMergeRules(a[i], pX);
    }
    for(pX=a[0], i=1; i<sizeof(a)/sizeof(a[0]); i++){
      pX = amatchMergeRules(a[i], pX);
    }
    p->pRule = amatchMergeRules(p->pRule, pX);
  }else{
    /* An error has occurred. Setting p->pRule to point to the head of the
    ** allocated list ensures that the list will be cleaned up in this case.
    */
    assert( p->pRule==0 );
    p->pRule = pHead;
  }

  return rc;
}

/*
** This function converts an SQL quoted string into an unquoted string
** and returns a pointer to a buffer allocated using sqlite3_malloc() 
** containing the result. The caller should eventually free this buffer
** using sqlite3_free.
**
** Examples:
**
**     "abc"   becomes   abc
**     'xyz'   becomes   xyz
**     [pqr]   becomes   pqr
**     `mno`   becomes   mno
*/
static char *amatchDequote(const char *zIn){
  int nIn;                        /* Size of input string, in bytes */
  char *zOut;                     /* Output (dequoted) string */

  nIn = (int)strlen(zIn);
  zOut = sqlite3_malloc(nIn+1);
  if( zOut ){
    char q = zIn[0];              /* Quote character (if any ) */

    if( q!='[' && q!= '\'' && q!='"' && q!='`' ){
      memcpy(zOut, zIn, nIn+1);
    }else{
      int iOut = 0;               /* Index of next byte to write to output */
      int iIn;                    /* Index of next byte to read from input */

      if( q=='[' ) q = ']';
      for(iIn=1; iIn<nIn; iIn++){
        if( zIn[iIn]==q ) iIn++;
        zOut[iOut++] = zIn[iIn];
      }
    }
    assert( (int)strlen(zOut)<=nIn );
  }
  return zOut;
}

/*
** Deallocate the pVCheck prepared statement.
*/
static void amatchVCheckClear(amatch_vtab *p){
  if( p->pVCheck ){
    sqlite3_finalize(p->pVCheck);
    p->pVCheck = 0;
  }
}

/*
** Deallocate an amatch_vtab object
*/
static void amatchFree(amatch_vtab *p){
  if( p ){
    amatchFreeRules(p);
    amatchVCheckClear(p);
    sqlite3_free(p->zClassName);
    sqlite3_free(p->zDb);
    sqlite3_free(p->zCostTab);
    sqlite3_free(p->zVocabTab);
    sqlite3_free(p->zVocabWord);
    sqlite3_free(p->zVocabLang);
    memset(p, 0, sizeof(*p));
    sqlite3_free(p);
  }
}

/*
** xDisconnect/xDestroy method for the amatch module.
*/
static int amatchDisconnect(sqlite3_vtab *pVtab){
  amatch_vtab *p = (amatch_vtab*)pVtab;
  assert( p->nCursor==0 );
  amatchFree(p);
  return SQLITE_OK;
}

/*
** Check to see if the argument is of the form:
**
**       KEY = VALUE
**
** If it is, return a pointer to the first character of VALUE.
** If not, return NULL.  Spaces around the = are ignored.
*/
static const char *amatchValueOfKey(const char *zKey, const char *zStr){
  int nKey = (int)strlen(zKey);
  int nStr = (int)strlen(zStr);
  int i;
  if( nStr<nKey+1 ) return 0;
  if( memcmp(zStr, zKey, nKey)!=0 ) return 0;
  for(i=nKey; isspace(zStr[i]); i++){}
  if( zStr[i]!='=' ) return 0;
  i++;
  while( isspace(zStr[i]) ){ i++; }
  return zStr+i;
}

/*
** xConnect/xCreate method for the amatch module. Arguments are:
**
**   argv[0]    -> module name  ("approximate_match")
**   argv[1]    -> database name
**   argv[2]    -> table name
**   argv[3...] -> arguments
*/
static int amatchConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int rc = SQLITE_OK;             /* Return code */
  amatch_vtab *pNew = 0;          /* New virtual table */
  const char *zModule = argv[0];
  const char *zDb = argv[1];
  const char *zVal;
  int i;

  (void)pAux;
  *ppVtab = 0;
  pNew = sqlite3_malloc( sizeof(*pNew) );
  if( pNew==0 ) return SQLITE_NOMEM;
  rc = SQLITE_NOMEM;
  memset(pNew, 0, sizeof(*pNew));
  pNew->db = db;
  pNew->zClassName = sqlite3_mprintf("%s", zModule);
  if( pNew->zClassName==0 ) goto amatchConnectError;
  pNew->zDb = sqlite3_mprintf("%s", zDb);
  if( pNew->zDb==0 ) goto amatchConnectError;
  pNew->zSelf = sqlite3_mprintf("%s", argv[2]);
  if( pNew->zSelf==0 ) goto amatchConnectError;
  for(i=3; i<argc; i++){
    zVal = amatchValueOfKey("vocabulary_table", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zVocabTab);
      pNew->zVocabTab = amatchDequote(zVal);
      if( pNew->zVocabTab==0 ) goto amatchConnectError;
      continue;
    }
    zVal = amatchValueOfKey("vocabulary_word", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zVocabWord);
      pNew->zVocabWord = amatchDequote(zVal);
      if( pNew->zVocabWord==0 ) goto amatchConnectError;
      continue;
    }
    zVal = amatchValueOfKey("vocabulary_language", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zVocabLang);
      pNew->zVocabLang = amatchDequote(zVal);
      if( pNew->zVocabLang==0 ) goto amatchConnectError;
      continue;
    }
    zVal = amatchValueOfKey("edit_distances", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zCostTab);
      pNew->zCostTab = amatchDequote(zVal);
      if( pNew->zCostTab==0 ) goto amatchConnectError;
      continue;
    }
    *pzErr = sqlite3_mprintf("unrecognized argument: [%s]\n", argv[i]);
    amatchFree(pNew);
    *ppVtab = 0;
    return SQLITE_ERROR;
  }
  rc = SQLITE_OK;
  if( pNew->zCostTab==0 ){
    *pzErr = sqlite3_mprintf("no edit_distances table specified");
    rc = SQLITE_ERROR;
  }else{
    rc = amatchLoadRules(db, pNew, pzErr);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_declare_vtab(db,
           "CREATE TABLE x(word,distance,language,"
           "command HIDDEN,nword HIDDEN)"
         );
#define AMATCH_COL_WORD       0
#define AMATCH_COL_DISTANCE   1
#define AMATCH_COL_LANGUAGE   2
#define AMATCH_COL_COMMAND    3
#define AMATCH_COL_NWORD      4
  }
  if( rc!=SQLITE_OK ){
    amatchFree(pNew);
  }
  *ppVtab = &pNew->base;
  return rc;

amatchConnectError:
  amatchFree(pNew);
  return rc;
}

/*
** Open a new amatch cursor.
*/
static int amatchOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  amatch_vtab *p = (amatch_vtab*)pVTab;
  amatch_cursor *pCur;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->pVtab = p;
  *ppCursor = &pCur->base;
  p->nCursor++;
  return SQLITE_OK;
}

/*
** Free up all the memory allocated by a cursor.  Set it rLimit to 0
** to indicate that it is at EOF.
*/
static void amatchClearCursor(amatch_cursor *pCur){
  amatch_word *pWord, *pNextWord;
  for(pWord=pCur->pAllWords; pWord; pWord=pNextWord){
    pNextWord = pWord->pNext;
    sqlite3_free(pWord);
  }
  pCur->pAllWords = 0;
  sqlite3_free(pCur->zInput);
  pCur->zInput = 0;
  pCur->pCost = 0;
  pCur->pWord = 0;
  pCur->pCurrent = 0;
  pCur->rLimit = 1000000;
  pCur->iLang = 0;
  pCur->nWord = 0;
}

/*
** Close a amatch cursor.
*/
static int amatchClose(sqlite3_vtab_cursor *cur){
  amatch_cursor *pCur = (amatch_cursor *)cur;
  amatchClearCursor(pCur);
  pCur->pVtab->nCursor--;
  sqlite3_free(pCur);
  return SQLITE_OK;
}

/*
** Render a 24-bit unsigned integer as a 4-byte base-64 number.
*/
static void amatchEncodeInt(int x, char *z){
  static const char a[] = 
    "0123456789"
    "ABCDEFGHIJ"
    "KLMNOPQRST"
    "UVWXYZ^abc"
    "defghijklm"
    "nopqrstuvw"
    "xyz~";
  z[0] = a[(x>>18)&0x3f];
  z[1] = a[(x>>12)&0x3f];
  z[2] = a[(x>>6)&0x3f];
  z[3] = a[x&0x3f];
}

/*
** Write the zCost[] field for a amatch_word object
*/
static void amatchWriteCost(amatch_word *pWord){
  amatchEncodeInt(pWord->rCost, pWord->zCost);
  amatchEncodeInt(pWord->iSeq, pWord->zCost+4);
  pWord->zCost[8] = 0;
}

/*
** Add a new amatch_word object to the queue.
**
** If a prior amatch_word object with the same zWord, and nMatch
** already exists, update its rCost (if the new rCost is less) but
** otherwise leave it unchanged.  Do not add a duplicate.
**
** Do nothing if the cost exceeds threshold.
*/
static void amatchAddWord(
  amatch_cursor *pCur,
  amatch_cost rCost,
  int nMatch,
  const char *zWordBase,
  const char *zWordTail
){
  amatch_word *pWord;
  amatch_avl *pNode;
  amatch_avl *pOther;
  int nBase, nTail;
  char zBuf[4];
  
  if( rCost>pCur->rLimit ){
    return;
  }
  nBase = (int)strlen(zWordBase);
  nTail = (int)strlen(zWordTail);
  if( nBase+nTail+3>pCur->nBuf ){
    pCur->nBuf = nBase+nTail+100;
    pCur->zBuf = sqlite3_realloc(pCur->zBuf, pCur->nBuf);
    if( pCur->zBuf==0 ){
      pCur->nBuf = 0;
      return;
    }
  }
  amatchEncodeInt(nMatch, zBuf);
  memcpy(pCur->zBuf, zBuf+2, 2);
  memcpy(pCur->zBuf+2, zWordBase, nBase);
  memcpy(pCur->zBuf+2+nBase, zWordTail, nTail+1);
  pNode = amatchAvlSearch(pCur->pWord, pCur->zBuf);
  if( pNode ){
    pWord = pNode->pWord;
    if( pWord->rCost>rCost ){
#ifdef AMATCH_TRACE_1
      printf("UPDATE [%s][%.*s^%s] %d (\"%s\" \"%s\")\n",
             pWord->zWord+2, pWord->nMatch, pCur->zInput, pCur->zInput,
             pWord->rCost, pWord->zWord, pWord->zCost);
#endif
      amatchAvlRemove(&pCur->pCost, &pWord->sCost);
      pWord->rCost = rCost;
      amatchWriteCost(pWord);
#ifdef AMATCH_TRACE_1
      printf("  ---> %d (\"%s\" \"%s\")\n",
             pWord->rCost, pWord->zWord, pWord->zCost);
#endif
      pOther = amatchAvlInsert(&pCur->pCost, &pWord->sCost);
      assert( pOther==0 ); (void)pOther;
    }
    return;
  }
  pWord = sqlite3_malloc( sizeof(*pWord) + nBase + nTail - 1 );
  if( pWord==0 ) return;
  memset(pWord, 0, sizeof(*pWord));
  pWord->rCost = rCost;
  pWord->iSeq = pCur->nWord++;
  amatchWriteCost(pWord);
  pWord->nMatch = nMatch;
  pWord->pNext = pCur->pAllWords;
  pCur->pAllWords = pWord;
  pWord->sCost.zKey = pWord->zCost;
  pWord->sCost.pWord = pWord;
  pOther = amatchAvlInsert(&pCur->pCost, &pWord->sCost);
  assert( pOther==0 ); (void)pOther;
  pWord->sWord.zKey = pWord->zWord;
  pWord->sWord.pWord = pWord;
  strcpy(pWord->zWord, pCur->zBuf);
  pOther = amatchAvlInsert(&pCur->pWord, &pWord->sWord);
  assert( pOther==0 ); (void)pOther;
#ifdef AMATCH_TRACE_1
  printf("INSERT [%s][%.*s^%s] %d (\"%s\" \"%s\")\n", pWord->zWord+2,
       pWord->nMatch, pCur->zInput, pCur->zInput+pWord->nMatch, rCost,
       pWord->zWord, pWord->zCost);
#endif
}

/*
** Advance a cursor to its next row of output
*/
static int amatchNext(sqlite3_vtab_cursor *cur){
  amatch_cursor *pCur = (amatch_cursor*)cur;
  amatch_word *pWord = 0;
  amatch_avl *pNode;
  int isMatch = 0;
  amatch_vtab *p = pCur->pVtab;
  int nWord;
  int rc;
  int i;
  const char *zW;
  amatch_rule *pRule;
  char *zBuf = 0;
  char nBuf = 0;
  char zNext[8];
  char zNextIn[8];
  int nNextIn;

  if( p->pVCheck==0 ){
    char *zSql;
    if( p->zVocabLang && p->zVocabLang[0] ){
      zSql = sqlite3_mprintf(
          "SELECT \"%s\" FROM \"%s\"",
          " WHERE \"%w\">=?1 AND \"%w\"=?2"
          " ORDER BY 1",
          p->zVocabWord, p->zVocabTab,
          p->zVocabWord, p->zVocabLang
      );
    }else{
      zSql = sqlite3_mprintf(
          "SELECT \"%s\" FROM \"%s\""
          " WHERE \"%w\">=?1"
          " ORDER BY 1",
          p->zVocabWord, p->zVocabTab,
          p->zVocabWord
      );
    }
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &p->pVCheck, 0);
    sqlite3_free(zSql);
    if( rc ) return rc;
  }
  sqlite3_bind_int(p->pVCheck, 2, pCur->iLang);

  do{
    pNode = amatchAvlFirst(pCur->pCost);
    if( pNode==0 ){
      pWord = 0;
      break;
    }
    pWord = pNode->pWord;
    amatchAvlRemove(&pCur->pCost, &pWord->sCost);

#ifdef AMATCH_TRACE_1
    printf("PROCESS [%s][%.*s^%s] %d (\"%s\" \"%s\")\n",
       pWord->zWord+2, pWord->nMatch, pCur->zInput, pCur->zInput+pWord->nMatch,
       pWord->rCost, pWord->zWord, pWord->zCost);
#endif
    nWord = (int)strlen(pWord->zWord+2);
    if( nWord+20>nBuf ){
      nBuf = nWord+100;
      zBuf = sqlite3_realloc(zBuf, nBuf);
      if( zBuf==0 ) return SQLITE_NOMEM;
    }
    strcpy(zBuf, pWord->zWord+2);
    zNext[0] = 0;
    zNextIn[0] = pCur->zInput[pWord->nMatch];
    if( zNextIn[0] ){
      for(i=1; i<=4 && (pCur->zInput[pWord->nMatch+i]&0xc0)==0x80; i++){
        zNextIn[i] = pCur->zInput[pWord->nMatch+i];
      }
      zNextIn[i] = 0;
      nNextIn = i;
    }else{
      nNextIn = 0;
    }

    if( zNextIn[0] && zNextIn[0]!='*' ){
      sqlite3_reset(p->pVCheck);
      strcat(zBuf, zNextIn);
      sqlite3_bind_text(p->pVCheck, 1, zBuf, nWord+nNextIn, SQLITE_STATIC);
      rc = sqlite3_step(p->pVCheck);
      if( rc==SQLITE_ROW ){
        zW = (const char*)sqlite3_column_text(p->pVCheck, 0);
        if( strncmp(zBuf, zW, nWord+nNextIn)==0 ){
          amatchAddWord(pCur, pWord->rCost, pWord->nMatch+nNextIn, zBuf, "");
        }
      }
      zBuf[nWord] = 0;
    }

    while( 1 ){
      strcpy(zBuf+nWord, zNext);
      sqlite3_reset(p->pVCheck);
      sqlite3_bind_text(p->pVCheck, 1, zBuf, -1, SQLITE_TRANSIENT);
      rc = sqlite3_step(p->pVCheck);
      if( rc!=SQLITE_ROW ) break;
      zW = (const char*)sqlite3_column_text(p->pVCheck, 0);
      strcpy(zBuf+nWord, zNext);
      if( strncmp(zW, zBuf, nWord)!=0 ) break;
      if( (zNextIn[0]=='*' && zNextIn[1]==0)
       || (zNextIn[0]==0 && zW[nWord]==0)
      ){
        isMatch = 1;
        zNextIn[0] = 0;
        nNextIn = 0;
        break;
      }
      zNext[0] = zW[nWord];
      for(i=1; i<=4 && (zW[nWord+i]&0xc0)==0x80; i++){
        zNext[i] = zW[nWord+i];
      }
      zNext[i] = 0;
      zBuf[nWord] = 0;
      if( p->rIns>0 ){
        amatchAddWord(pCur, pWord->rCost+p->rIns, pWord->nMatch, 
                      zBuf, zNext);
      }
      if( p->rSub>0 ){
        amatchAddWord(pCur, pWord->rCost+p->rSub, pWord->nMatch+nNextIn, 
                      zBuf, zNext);
      }
      if( p->rIns<0 && p->rSub<0 ) break;
      zNext[i-1]++;  /* FIX ME */
    }
    sqlite3_reset(p->pVCheck);

    if( p->rDel>0 ){
      zBuf[nWord] = 0;
      amatchAddWord(pCur, pWord->rCost+p->rDel, pWord->nMatch+nNextIn,
                    zBuf, "");
    }

    for(pRule=p->pRule; pRule; pRule=pRule->pNext){
      if( pRule->iLang!=pCur->iLang ) continue;
      if( strncmp(pRule->zFrom, pCur->zInput+pWord->nMatch, pRule->nFrom)==0 ){
        amatchAddWord(pCur, pWord->rCost+pRule->rCost,
                      pWord->nMatch+pRule->nFrom, pWord->zWord+2, pRule->zTo);
      }
    }
  }while( !isMatch );
  pCur->pCurrent = pWord;
  sqlite3_free(zBuf);
  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 amatchColumn, amatchRowid, or amatchEof call.
*/
static int amatchFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  amatch_cursor *pCur = (amatch_cursor *)pVtabCursor;
  const char *zWord = "*";
  int idx;

  amatchClearCursor(pCur);
  idx = 0;
  if( idxNum & 1 ){
    zWord = (const char*)sqlite3_value_text(argv[0]);
    idx++;
  }
  if( idxNum & 2 ){
    pCur->rLimit = (amatch_cost)sqlite3_value_int(argv[idx]);
    idx++;
  }
  if( idxNum & 4 ){
    pCur->iLang = (amatch_cost)sqlite3_value_int(argv[idx]);
    idx++;
  }
  pCur->zInput = sqlite3_mprintf("%s", zWord);
  if( pCur->zInput==0 ) return SQLITE_NOMEM;
  amatchAddWord(pCur, 0, 0, "", "");
  amatchNext(pVtabCursor);

  return SQLITE_OK;
}

/*
** Only the word and distance columns have values.  All other columns
** return NULL
*/
static int amatchColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  amatch_cursor *pCur = (amatch_cursor*)cur;
  switch( i ){
    case AMATCH_COL_WORD: {
      sqlite3_result_text(ctx, pCur->pCurrent->zWord+2, -1, SQLITE_STATIC);
      break;
    }
    case AMATCH_COL_DISTANCE: {
      sqlite3_result_int(ctx, pCur->pCurrent->rCost);
      break;
    }
    case AMATCH_COL_LANGUAGE: {
      sqlite3_result_int(ctx, pCur->iLang);
      break;
    }
    case AMATCH_COL_NWORD: {
      sqlite3_result_int(ctx, pCur->nWord);
      break;
    }
    default: {
      sqlite3_result_null(ctx);
      break;
    }
  }
  return SQLITE_OK;
}

/*
** The rowid.
*/
static int amatchRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  amatch_cursor *pCur = (amatch_cursor*)cur;
  *pRowid = pCur->iRowid;
  return SQLITE_OK;
}

/*
** EOF indicator
*/
static int amatchEof(sqlite3_vtab_cursor *cur){
  amatch_cursor *pCur = (amatch_cursor*)cur;
  return pCur->pCurrent==0;
}

/*
** Search for terms of these forms:
**
**   (A)    word MATCH $str
**   (B1)   distance < $value
**   (B2)   distance <= $value
**   (C)    language == $language
**
** The distance< and distance<= are both treated as distance<=.
** The query plan number is a bit vector:
**
**   bit 1:   Term of the form (A) found
**   bit 2:   Term like (B1) or (B2) found
**   bit 3:   Term like (C) found
**
** If bit-1 is set, $str is always in filter.argv[0].  If bit-2 is set
** then $value is in filter.argv[0] if bit-1 is clear and is in 
** filter.argv[1] if bit-1 is set.  If bit-3 is set, then $ruleid is
** in filter.argv[0] if bit-1 and bit-2 are both zero, is in
** filter.argv[1] if exactly one of bit-1 and bit-2 are set, and is in
** filter.argv[2] if both bit-1 and bit-2 are set.
*/
static int amatchBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int iPlan = 0;
  int iDistTerm = -1;
  int iLangTerm = -1;
  int i;
  const struct sqlite3_index_constraint *pConstraint;

  (void)tab;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    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;
    }
    if( (iPlan & 2)==0
     && pConstraint->iColumn==1
     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
    ){
      iPlan |= 2;
      iDistTerm = i;
    }
    if( (iPlan & 4)==0
     && pConstraint->iColumn==2
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= 4;
      pIdxInfo->aConstraintUsage[i].omit = 1;
      iLangTerm = i;
    }
  }
  if( iPlan & 2 ){
    pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = 1+((iPlan&1)!=0);
  }
  if( iPlan & 4 ){
    int idx = 1;
    if( iPlan & 1 ) idx++;
    if( iPlan & 2 ) idx++;
    pIdxInfo->aConstraintUsage[iLangTerm].argvIndex = idx;
  }
  pIdxInfo->idxNum = iPlan;
  if( pIdxInfo->nOrderBy==1
   && pIdxInfo->aOrderBy[0].iColumn==1
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }
  pIdxInfo->estimatedCost = (double)10000;
   
  return SQLITE_OK;
}

/*
** The xUpdate() method.  
**
** This implementation disallows DELETE and UPDATE.  The only thing
** allowed is INSERT into the "command" column.
*/
static int amatchUpdate(
  sqlite3_vtab *pVTab,
  int argc,
  sqlite3_value **argv,
  sqlite_int64 *pRowid
){
  amatch_vtab *p = (amatch_vtab*)pVTab;
  const unsigned char *zCmd;
  (void)pRowid;
  if( argc==1 ){
    pVTab->zErrMsg = sqlite3_mprintf("DELETE from %s is not allowed", 
                                      p->zSelf);
    return SQLITE_ERROR;
  }
  if( sqlite3_value_type(argv[0])!=SQLITE_NULL ){
    pVTab->zErrMsg = sqlite3_mprintf("UPDATE of %s is not allowed", 
                                      p->zSelf);
    return SQLITE_ERROR;
  }
  if( sqlite3_value_type(argv[2+AMATCH_COL_WORD])!=SQLITE_NULL
   || sqlite3_value_type(argv[2+AMATCH_COL_DISTANCE])!=SQLITE_NULL
   || sqlite3_value_type(argv[2+AMATCH_COL_LANGUAGE])!=SQLITE_NULL
  ){
    pVTab->zErrMsg = sqlite3_mprintf(
            "INSERT INTO %s allowed for column [command] only", p->zSelf);
    return SQLITE_ERROR;
  }
  zCmd = sqlite3_value_text(argv[2+AMATCH_COL_COMMAND]);
  if( zCmd==0 ) return SQLITE_OK;
  
  return SQLITE_OK;
}

/*
** A virtual table module that implements the "approximate_match".
*/
static sqlite3_module amatchModule = {
  0,                      /* iVersion */
  amatchConnect,          /* xCreate */
  amatchConnect,          /* xConnect */
  amatchBestIndex,        /* xBestIndex */
  amatchDisconnect,       /* xDisconnect */
  amatchDisconnect,       /* xDestroy */
  amatchOpen,             /* xOpen - open a cursor */
  amatchClose,            /* xClose - close a cursor */
  amatchFilter,           /* xFilter - configure scan constraints */
  amatchNext,             /* xNext - advance a cursor */
  amatchEof,              /* xEof - check for end of scan */
  amatchColumn,           /* xColumn - read data */
  amatchRowid,            /* xRowid - read data */
  amatchUpdate,           /* xUpdate */
  0,                      /* xBegin */
  0,                      /* xSync */
  0,                      /* xCommit */
  0,                      /* xRollback */
  0,                      /* xFindMethod */
  0,                      /* xRename */
  0,                      /* xSavepoint */
  0,                      /* xRelease */
  0                       /* xRollbackTo */
};

/*
** Register the amatch virtual table
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_amatch_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Not used */
  rc = sqlite3_create_module(db, "approximate_match", &amatchModule, 0);
  return rc;
}

/*
** 2013-04-16
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code for a virtual table that finds the transitive
** closure of a parent/child relationship in a real table.  The virtual 
** table is called "transitive_closure".
**
** A transitive_closure virtual table is created like this:
**
**     CREATE VIRTUAL TABLE x USING transitive_closure(
**        tablename=<tablename>,      -- T
**        idcolumn=<columnname>,      -- X
**        parentcolumn=<columnname>   -- P
**     );
**
** When it is created, the new transitive_closure table may be supplied 
** with default values for the name of a table T and columns T.X and T.P.
** The T.X and T.P columns must contain integers.  The ideal case is for 
** T.X to be the INTEGER PRIMARY KEY.  The T.P column should reference
** the T.X column. The row referenced by T.P is the parent of the current row.
**
** The tablename, idcolumn, and parentcolumn supplied by the CREATE VIRTUAL
** TABLE statement may be overridden in individual queries by including
** terms like tablename='newtable', idcolumn='id2', or 
** parentcolumn='parent3' in the WHERE clause of the query.
**
** For efficiency, it is essential that there be an index on the P column:
**
**    CREATE Tidx1 ON T(P)
**
** Suppose a specific instance of the closure table is as follows:
**
**    CREATE VIRTUAL TABLE ct1 USING transitive_closure(
**       tablename='group',
**       idcolumn='groupId',
**       parentcolumn='parentId'
**    );
**
** Such an instance of the transitive_closure virtual table would be
** appropriate for walking a tree defined using a table like this, for example:
**
**    CREATE TABLE group(
**      groupId INTEGER PRIMARY KEY,
**      parentId INTEGER REFERENCES group
**    );
**    CREATE INDEX group_idx1 ON group(parentId);
**
** The group table above would presumably have other application-specific
** fields.  The key point here is that rows of the group table form a
** tree.  The purpose of the ct1 virtual table is to easily extract
** branches of that tree.
**
** Once it has been created, the ct1 virtual table can be queried
** as follows:
**
**    SELECT * FROM element
**     WHERE element.groupId IN (SELECT id FROM ct1 WHERE root=?1);
**
** The above query will return all elements that are part of group ?1
** or children of group ?1 or grand-children of ?1 and so forth for all
** descendents of group ?1.  The same query can be formulated as a join:
**
**    SELECT element.* FROM element, ct1
**     WHERE element.groupid=ct1.id
**       AND ct1.root=?1;
**
** The depth of the transitive_closure (the number of generations of
** parent/child relations to follow) can be limited by setting "depth"
** column in the WHERE clause.  So, for example, the following query
** finds only children and grandchildren but no further descendents:
**
**    SELECT element.* FROM element, ct1
**     WHERE element.groupid=ct1.id
**       AND ct1.root=?1
**       AND ct1.depth<=2;
**
** The "ct1.depth<=2" term could be a strict equality "ct1.depth=2" in
** order to find only the grandchildren of ?1, not ?1 itself or the
** children of ?1.
** 
** The root=?1 term must be supplied in WHERE clause or else the query
** of the ct1 virtual table will return an empty set.  The tablename,
** idcolumn, and parentcolumn attributes can be overridden in the WHERE
** clause if desired.  So, for example, the ct1 table could be repurposed
** to find ancestors rather than descendents by inverting the roles of
** the idcolumn and parentcolumn:
**
**    SELECT element.* FROM element, ct1
**     WHERE element.groupid=ct1.id
**       AND ct1.root=?1
**       AND ct1.idcolumn='parentId'
**       AND ct1.parentcolumn='groupId';
**
** Multiple calls to ct1 could be combined.  For example, the following
** query finds all elements that "cousins" of groupId ?1.  That is to say
** elements where the groupId is a grandchild of the grandparent of ?1.
** (This definition of "cousins" also includes siblings and self.)
**
**    SELECT element.* FROM element, ct1
**     WHERE element.groupId=ct1.id
**       AND ct1.depth=2
**       AND ct1.root IN (SELECT id FROM ct1
**                         WHERE root=?1
**                           AND depth=2
**                           AND idcolumn='parentId'
**                           AND parentcolumn='groupId');
**
** In our example, the group.groupId column is unique and thus the
** subquery will return exactly one row.  For that reason, the IN
** operator could be replaced by "=" to get the same result.  But
** in the general case where the idcolumn is not unique, an IN operator
** would be required for this kind of query.
**
** Note that because the tablename, idcolumn, and parentcolumn can
** all be specified in the query, it is possible for an application
** to define a single transitive_closure virtual table for use on lots
** of different hierarchy tables.  One might say:
**
**     CREATE VIRTUAL TABLE temp.closure USING transitive_closure;
**
** As each database connection is being opened.  Then the application
** would always have a "closure" virtual table handy to use for querying.
**
**    SELECT element.* FROM element, closure
**     WHERE element.groupid=ct1.id
**       AND closure.root=?1
**       AND closure.tablename='group'
**       AND closure.idname='groupId'
**       AND closure.parentname='parentId';
**
** See the documentation at http://www.sqlite.org/loadext.html for information
** on how to compile and use loadable extensions such as this one.
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <ctype.h>

/*
** Forward declaration of objects used by this implementation
*/
typedef struct closure_vtab closure_vtab;
typedef struct closure_cursor closure_cursor;
typedef struct closure_queue closure_queue;
typedef struct closure_avl closure_avl;

/*****************************************************************************
** AVL Tree implementation
*/
/*
** Objects that want to be members of the AVL tree should embedded an
** instance of this structure.
*/
struct closure_avl {
  sqlite3_int64 id;     /* Id of this entry in the table */
  int iGeneration;      /* Which generation is this entry part of */
  closure_avl *pList;   /* A linked list of nodes */
  closure_avl *pBefore; /* Other elements less than id */
  closure_avl *pAfter;  /* Other elements greater than id */
  closure_avl *pUp;     /* Parent element */
  short int height;     /* Height of this node.  Leaf==1 */
  short int imbalance;  /* Height difference between pBefore and pAfter */
};

/* Recompute the closure_avl.height and closure_avl.imbalance fields for p.
** Assume that the children of p have correct heights.
*/
static void closureAvlRecomputeHeight(closure_avl *p){
  short int hBefore = p->pBefore ? p->pBefore->height : 0;
  short int hAfter = p->pAfter ? p->pAfter->height : 0;
  p->imbalance = hBefore - hAfter;  /* -: pAfter higher.  +: pBefore higher */
  p->height = (hBefore>hAfter ? hBefore : hAfter)+1;
}

/*
**     P                B
**    / \              / \
**   B   Z    ==>     X   P
**  / \                  / \
** X   Y                Y   Z
**
*/
static closure_avl *closureAvlRotateBefore(closure_avl *pP){
  closure_avl *pB = pP->pBefore;
  closure_avl *pY = pB->pAfter;
  pB->pUp = pP->pUp;
  pB->pAfter = pP;
  pP->pUp = pB;
  pP->pBefore = pY;
  if( pY ) pY->pUp = pP;
  closureAvlRecomputeHeight(pP);
  closureAvlRecomputeHeight(pB);
  return pB;
}

/*
**     P                A
**    / \              / \
**   X   A    ==>     P   Z
**      / \          / \
**     Y   Z        X   Y
**
*/
static closure_avl *closureAvlRotateAfter(closure_avl *pP){
  closure_avl *pA = pP->pAfter;
  closure_avl *pY = pA->pBefore;
  pA->pUp = pP->pUp;
  pA->pBefore = pP;
  pP->pUp = pA;
  pP->pAfter = pY;
  if( pY ) pY->pUp = pP;
  closureAvlRecomputeHeight(pP);
  closureAvlRecomputeHeight(pA);
  return pA;
}

/*
** Return a pointer to the pBefore or pAfter pointer in the parent
** of p that points to p.  Or if p is the root node, return pp.
*/
static closure_avl **closureAvlFromPtr(closure_avl *p, closure_avl **pp){
  closure_avl *pUp = p->pUp;
  if( pUp==0 ) return pp;
  if( pUp->pAfter==p ) return &pUp->pAfter;
  return &pUp->pBefore;
}

/*
** Rebalance all nodes starting with p and working up to the root.
** Return the new root.
*/
static closure_avl *closureAvlBalance(closure_avl *p){
  closure_avl *pTop = p;
  closure_avl **pp;
  while( p ){
    closureAvlRecomputeHeight(p);
    if( p->imbalance>=2 ){
      closure_avl *pB = p->pBefore;
      if( pB->imbalance<0 ) p->pBefore = closureAvlRotateAfter(pB);
      pp = closureAvlFromPtr(p,&p);
      p = *pp = closureAvlRotateBefore(p);
    }else if( p->imbalance<=(-2) ){
      closure_avl *pA = p->pAfter;
      if( pA->imbalance>0 ) p->pAfter = closureAvlRotateBefore(pA);
      pp = closureAvlFromPtr(p,&p);
      p = *pp = closureAvlRotateAfter(p);
    }
    pTop = p;
    p = p->pUp;
  }
  return pTop;
}

/* Search the tree rooted at p for an entry with id.  Return a pointer
** to the entry or return NULL.
*/
static closure_avl *closureAvlSearch(closure_avl *p, sqlite3_int64 id){
  while( p && id!=p->id ){
    p = (id<p->id) ? p->pBefore : p->pAfter;
  }
  return p;
}

/* Find the first node (the one with the smallest key).
*/
static closure_avl *closureAvlFirst(closure_avl *p){
  if( p ) while( p->pBefore ) p = p->pBefore;
  return p;
}

/* Return the node with the next larger key after p.
*/
closure_avl *closureAvlNext(closure_avl *p){
  closure_avl *pPrev = 0;
  while( p && p->pAfter==pPrev ){
    pPrev = p;
    p = p->pUp;
  }
  if( p && pPrev==0 ){
    p = closureAvlFirst(p->pAfter);
  }
  return p;
}
	
/* Insert a new node pNew.  Return NULL on success.  If the key is not
** unique, then do not perform the insert but instead leave pNew unchanged
** and return a pointer to an existing node with the same key.
*/
static closure_avl *closureAvlInsert(
  closure_avl **ppHead,  /* Head of the tree */
  closure_avl *pNew      /* New node to be inserted */
){
  closure_avl *p = *ppHead;
  if( p==0 ){
    p = pNew;
    pNew->pUp = 0;
  }else{
    while( p ){
      if( pNew->id<p->id ){
        if( p->pBefore ){
          p = p->pBefore;
        }else{
          p->pBefore = pNew;
          pNew->pUp = p;
          break;
        }
      }else if( pNew->id>p->id ){
        if( p->pAfter ){
          p = p->pAfter;
        }else{
          p->pAfter = pNew;
          pNew->pUp = p;
          break;
        }
      }else{
        return p;
      }
    }
  }
  pNew->pBefore = 0;
  pNew->pAfter = 0;
  pNew->height = 1;
  pNew->imbalance = 0;
  *ppHead = closureAvlBalance(p);
  return 0;
}

/* Walk the tree can call xDestroy on each node
*/
static void closureAvlDestroy(closure_avl *p, void (*xDestroy)(closure_avl*)){
  if( p ){
    closureAvlDestroy(p->pBefore, xDestroy);
    closureAvlDestroy(p->pAfter, xDestroy);
    xDestroy(p);
  }
}
/*
** End of the AVL Tree implementation
******************************************************************************/

/* 
** A closure virtual-table object 
*/
struct closure_vtab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zDb;                 /* Name of database.  (ex: "main") */
  char *zSelf;               /* Name of this virtual table */
  char *zTableName;          /* Name of table holding parent/child relation */
  char *zIdColumn;           /* Name of ID column of zTableName */
  char *zParentColumn;       /* Name of PARENT column in zTableName */
  sqlite3 *db;               /* The database connection */
  int nCursor;               /* Number of pending cursors */
};

/* A closure cursor object */
struct closure_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  closure_vtab *pVtab;       /* The virtual table this cursor belongs to */
  char *zTableName;          /* Name of table holding parent/child relation */
  char *zIdColumn;           /* Name of ID column of zTableName */
  char *zParentColumn;       /* Name of PARENT column in zTableName */
  closure_avl *pCurrent;     /* Current element of output */
  closure_avl *pClosure;     /* The complete closure tree */
};

/* A queue of AVL nodes */
struct closure_queue {
  closure_avl *pFirst;       /* Oldest node on the queue */
  closure_avl *pLast;        /* Youngest node on the queue */
};

/*
** Add a node to the end of the queue
*/
static void queuePush(closure_queue *pQueue, closure_avl *pNode){
  pNode->pList = 0;
  if( pQueue->pLast ){
    pQueue->pLast->pList = pNode;
  }else{
    pQueue->pFirst = pNode;
  }
  pQueue->pLast = pNode;
}

/*
** Extract the oldest element (the front element) from the queue.
*/
static closure_avl *queuePull(closure_queue *pQueue){
  closure_avl *p = pQueue->pFirst;
  if( p ){
    pQueue->pFirst = p->pList;
    if( pQueue->pFirst==0 ) pQueue->pLast = 0;
  }
  return p;
}

/*
** This function converts an SQL quoted string into an unquoted string
** and returns a pointer to a buffer allocated using sqlite3_malloc() 
** containing the result. The caller should eventually free this buffer
** using sqlite3_free.
**
** Examples:
**
**     "abc"   becomes   abc
**     'xyz'   becomes   xyz
**     [pqr]   becomes   pqr
**     `mno`   becomes   mno
*/
static char *closureDequote(const char *zIn){
  int nIn;                        /* Size of input string, in bytes */
  char *zOut;                     /* Output (dequoted) string */

  nIn = (int)strlen(zIn);
  zOut = sqlite3_malloc(nIn+1);
  if( zOut ){
    char q = zIn[0];              /* Quote character (if any ) */

    if( q!='[' && q!= '\'' && q!='"' && q!='`' ){
      memcpy(zOut, zIn, nIn+1);
    }else{
      int iOut = 0;               /* Index of next byte to write to output */
      int iIn;                    /* Index of next byte to read from input */

      if( q=='[' ) q = ']';
      for(iIn=1; iIn<nIn; iIn++){
        if( zIn[iIn]==q ) iIn++;
        zOut[iOut++] = zIn[iIn];
      }
    }
    assert( (int)strlen(zOut)<=nIn );
  }
  return zOut;
}

/*
** Deallocate an closure_vtab object
*/
static void closureFree(closure_vtab *p){
  if( p ){
    sqlite3_free(p->zDb);
    sqlite3_free(p->zSelf);
    sqlite3_free(p->zTableName);
    sqlite3_free(p->zIdColumn);
    sqlite3_free(p->zParentColumn);
    memset(p, 0, sizeof(*p));
    sqlite3_free(p);
  }
}

/*
** xDisconnect/xDestroy method for the closure module.
*/
static int closureDisconnect(sqlite3_vtab *pVtab){
  closure_vtab *p = (closure_vtab*)pVtab;
  assert( p->nCursor==0 );
  closureFree(p);
  return SQLITE_OK;
}

/*
** Check to see if the argument is of the form:
**
**       KEY = VALUE
**
** If it is, return a pointer to the first character of VALUE.
** If not, return NULL.  Spaces around the = are ignored.
*/
static const char *closureValueOfKey(const char *zKey, const char *zStr){
  int nKey = (int)strlen(zKey);
  int nStr = (int)strlen(zStr);
  int i;
  if( nStr<nKey+1 ) return 0;
  if( memcmp(zStr, zKey, nKey)!=0 ) return 0;
  for(i=nKey; isspace(zStr[i]); i++){}
  if( zStr[i]!='=' ) return 0;
  i++;
  while( isspace(zStr[i]) ){ i++; }
  return zStr+i;
}

/*
** xConnect/xCreate method for the closure module. Arguments are:
**
**   argv[0]    -> module name  ("approximate_match")
**   argv[1]    -> database name
**   argv[2]    -> table name
**   argv[3...] -> arguments
*/
static int closureConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int rc = SQLITE_OK;              /* Return code */
  closure_vtab *pNew = 0;          /* New virtual table */
  const char *zDb = argv[1];
  const char *zVal;
  int i;

  (void)pAux;
  *ppVtab = 0;
  pNew = sqlite3_malloc( sizeof(*pNew) );
  if( pNew==0 ) return SQLITE_NOMEM;
  rc = SQLITE_NOMEM;
  memset(pNew, 0, sizeof(*pNew));
  pNew->db = db;
  pNew->zDb = sqlite3_mprintf("%s", zDb);
  if( pNew->zDb==0 ) goto closureConnectError;
  pNew->zSelf = sqlite3_mprintf("%s", argv[2]);
  if( pNew->zSelf==0 ) goto closureConnectError;
  for(i=3; i<argc; i++){
    zVal = closureValueOfKey("tablename", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zTableName);
      pNew->zTableName = closureDequote(zVal);
      if( pNew->zTableName==0 ) goto closureConnectError;
      continue;
    }
    zVal = closureValueOfKey("idcolumn", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zIdColumn);
      pNew->zIdColumn = closureDequote(zVal);
      if( pNew->zIdColumn==0 ) goto closureConnectError;
      continue;
    }
    zVal = closureValueOfKey("parentcolumn", argv[i]);
    if( zVal ){
      sqlite3_free(pNew->zParentColumn);
      pNew->zParentColumn = closureDequote(zVal);
      if( pNew->zParentColumn==0 ) goto closureConnectError;
      continue;
    }
    *pzErr = sqlite3_mprintf("unrecognized argument: [%s]\n", argv[i]);
    closureFree(pNew);
    *ppVtab = 0;
    return SQLITE_ERROR;
  }
  rc = sqlite3_declare_vtab(db,
         "CREATE TABLE x(id,depth,root HIDDEN,tablename HIDDEN,"
                        "idcolumn HIDDEN,parentcolumn HIDDEN)"
       );
#define CLOSURE_COL_ID              0
#define CLOSURE_COL_DEPTH           1
#define CLOSURE_COL_ROOT            2
#define CLOSURE_COL_TABLENAME       3
#define CLOSURE_COL_IDCOLUMN        4
#define CLOSURE_COL_PARENTCOLUMN    5
  if( rc!=SQLITE_OK ){
    closureFree(pNew);
  }
  *ppVtab = &pNew->base;
  return rc;

closureConnectError:
  closureFree(pNew);
  return rc;
}

/*
** Open a new closure cursor.
*/
static int closureOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  closure_vtab *p = (closure_vtab*)pVTab;
  closure_cursor *pCur;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  pCur->pVtab = p;
  *ppCursor = &pCur->base;
  p->nCursor++;
  return SQLITE_OK;
}

/*
** Free up all the memory allocated by a cursor.  Set it rLimit to 0
** to indicate that it is at EOF.
*/
static void closureClearCursor(closure_cursor *pCur){
  closureAvlDestroy(pCur->pClosure, (void(*)(closure_avl*))sqlite3_free);
  sqlite3_free(pCur->zTableName);
  sqlite3_free(pCur->zIdColumn);
  sqlite3_free(pCur->zParentColumn);
  pCur->zTableName = 0;
  pCur->zIdColumn = 0;
  pCur->zParentColumn = 0;
  pCur->pCurrent = 0;
  pCur->pClosure = 0;
}

/*
** Close a closure cursor.
*/
static int closureClose(sqlite3_vtab_cursor *cur){
  closure_cursor *pCur = (closure_cursor *)cur;
  closureClearCursor(pCur);
  pCur->pVtab->nCursor--;
  sqlite3_free(pCur);
  return SQLITE_OK;
}

/*
** Advance a cursor to its next row of output
*/
static int closureNext(sqlite3_vtab_cursor *cur){
  closure_cursor *pCur = (closure_cursor*)cur;
  pCur->pCurrent = closureAvlNext(pCur->pCurrent);
  return SQLITE_OK;
}

/*
** Allocate and insert a node
*/
static int closureInsertNode(
  closure_queue *pQueue,  /* Add new node to this queue */
  closure_cursor *pCur,   /* The cursor into which to add the node */
  sqlite3_int64 id,       /* The node ID */
  int iGeneration         /* The generation number for this node */
){
  closure_avl *pNew = sqlite3_malloc( sizeof(*pNew) );
  if( pNew==0 ) return SQLITE_NOMEM;
  memset(pNew, 0, sizeof(*pNew));
  pNew->id = id;
  pNew->iGeneration = iGeneration;
  closureAvlInsert(&pCur->pClosure, pNew);
  queuePush(pQueue, pNew);
  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 closureColumn, closureRowid, or closureEof call.
**
** This routine actually computes the closure.
**
** See the comment at the beginning of closureBestIndex() for a 
** description of the meaning of idxNum.  The idxStr parameter is
** not used.
*/
static int closureFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  closure_cursor *pCur = (closure_cursor *)pVtabCursor;
  closure_vtab *pVtab = pCur->pVtab;
  sqlite3_int64 iRoot;
  int mxGen = 999999999;
  char *zSql;
  sqlite3_stmt *pStmt;
  closure_avl *pAvl;
  int rc = SQLITE_OK;
  const char *zTableName = pVtab->zTableName;
  const char *zIdColumn = pVtab->zIdColumn;
  const char *zParentColumn = pVtab->zParentColumn;
  closure_queue sQueue;

  (void)idxStr;  /* Unused parameter */
  (void)argc;    /* Unused parameter */
  closureClearCursor(pCur);
  memset(&sQueue, 0, sizeof(sQueue));
  if( (idxNum & 1)==0 ){
    /* No root=$root in the WHERE clause.  Return an empty set */
    return SQLITE_OK;
  }
  iRoot = sqlite3_value_int64(argv[0]);
  if( (idxNum & 0x000f0)!=0 ){
    mxGen = sqlite3_value_int(argv[(idxNum>>4)&0x0f]);
    if( (idxNum & 0x00002)!=0 ) mxGen--;
  }
  if( (idxNum & 0x00f00)!=0 ){
    zTableName = (const char*)sqlite3_value_text(argv[(idxNum>>8)&0x0f]);
    pCur->zTableName = sqlite3_mprintf("%s", zTableName);
  }
  if( (idxNum & 0x0f000)!=0 ){
    zIdColumn = (const char*)sqlite3_value_text(argv[(idxNum>>12)&0x0f]);
    pCur->zIdColumn = sqlite3_mprintf("%s", zIdColumn);
  }
  if( (idxNum & 0x0f0000)!=0 ){
    zParentColumn = (const char*)sqlite3_value_text(argv[(idxNum>>16)&0x0f]);
    pCur->zParentColumn = sqlite3_mprintf("%s", zParentColumn);
  }

  zSql = sqlite3_mprintf(
       "SELECT \"%w\".\"%w\" FROM \"%w\" WHERE \"%w\".\"%w\"=?1",
       zTableName, zIdColumn, zTableName, zTableName, zParentColumn);
  if( zSql==0 ){
    return SQLITE_NOMEM;
  }else{
    rc = sqlite3_prepare_v2(pVtab->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    if( rc ){
      sqlite3_free(pVtab->base.zErrMsg);
      pVtab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pVtab->db));
      return rc;
    }
  }
  if( rc==SQLITE_OK ){
    rc = closureInsertNode(&sQueue, pCur, iRoot, 0);
  }
  while( (pAvl = queuePull(&sQueue))!=0 ){
    if( pAvl->iGeneration>=mxGen ) continue;
    sqlite3_bind_int64(pStmt, 1, pAvl->id);
    while( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
      if( sqlite3_column_type(pStmt,0)==SQLITE_INTEGER ){
        sqlite3_int64 iNew = sqlite3_column_int64(pStmt, 0);
        if( closureAvlSearch(pCur->pClosure, iNew)==0 ){
          rc = closureInsertNode(&sQueue, pCur, iNew, pAvl->iGeneration+1);
        }
      }
    }
    sqlite3_reset(pStmt);
  }
  sqlite3_finalize(pStmt);
  if( rc==SQLITE_OK ){
    pCur->pCurrent = closureAvlFirst(pCur->pClosure);
  }

  return rc;
}

/*
** Only the word and distance columns have values.  All other columns
** return NULL
*/
static int closureColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  closure_cursor *pCur = (closure_cursor*)cur;
  switch( i ){
    case CLOSURE_COL_ID: {
      sqlite3_result_int64(ctx, pCur->pCurrent->id);
      break;
    }
    case CLOSURE_COL_DEPTH: {
      sqlite3_result_int(ctx, pCur->pCurrent->iGeneration);
      break;
    }
    case CLOSURE_COL_ROOT: {
      sqlite3_result_null(ctx);
      break;
    }
    case CLOSURE_COL_TABLENAME: {
      sqlite3_result_text(ctx,
         pCur->zTableName ? pCur->zTableName : pCur->pVtab->zTableName,
         -1, SQLITE_TRANSIENT);
      break;
    }
    case CLOSURE_COL_IDCOLUMN: {
      sqlite3_result_text(ctx,
         pCur->zIdColumn ? pCur->zIdColumn : pCur->pVtab->zIdColumn,
         -1, SQLITE_TRANSIENT);
      break;
    }
    case CLOSURE_COL_PARENTCOLUMN: {
      sqlite3_result_text(ctx,
         pCur->zParentColumn ? pCur->zParentColumn : pCur->pVtab->zParentColumn,
         -1, SQLITE_TRANSIENT);
      break;
    }
  }
  return SQLITE_OK;
}

/*
** The rowid.  For the closure table, this is the same as the "id" column.
*/
static int closureRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  closure_cursor *pCur = (closure_cursor*)cur;
  *pRowid = pCur->pCurrent->id;
  return SQLITE_OK;
}

/*
** EOF indicator
*/
static int closureEof(sqlite3_vtab_cursor *cur){
  closure_cursor *pCur = (closure_cursor*)cur;
  return pCur->pCurrent==0;
}

/*
** Search for terms of these forms:
**
**   (A)    root = $root
**   (B1)   depth < $depth
**   (B2)   depth <= $depth
**   (B3)   depth = $depth
**   (C)    tablename = $tablename
**   (D)    idcolumn = $idcolumn
**   (E)    parentcolumn = $parentcolumn
**
** 
**
**   idxNum       meaning
**   ----------   ------------------------------------------------------
**   0x00000001   Term of the form (A) found
**   0x00000002   The term of bit-2 is like (B1)
**   0x000000f0   Index in filter.argv[] of $depth.  0 if not used.
**   0x00000f00   Index in filter.argv[] of $tablename.  0 if not used.
**   0x0000f000   Index in filter.argv[] of $idcolumn.  0 if not used
**   0x000f0000   Index in filter.argv[] of $parentcolumn.  0 if not used.
**
** There must be a term of type (A).  If there is not, then the index type
** is 0 and the query will return an empty set.
*/
static int closureBestIndex(
  sqlite3_vtab *pTab,             /* The virtual table */
  sqlite3_index_info *pIdxInfo    /* Information about the query */
){
  int iPlan = 0;
  int i;
  int idx = 1;
  const struct sqlite3_index_constraint *pConstraint;
  closure_vtab *pVtab = (closure_vtab*)pTab;

  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( (iPlan & 1)==0 
     && pConstraint->iColumn==CLOSURE_COL_ROOT
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= 1;
      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
      pIdxInfo->aConstraintUsage[i].omit = 1;
    }
    if( (iPlan & 0x0000f0)==0
     && pConstraint->iColumn==CLOSURE_COL_DEPTH
     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE
           || pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ)
    ){
      iPlan |= idx<<4;
      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
      if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ) iPlan |= 0x000002;
    }
    if( (iPlan & 0x000f00)==0
     && pConstraint->iColumn==CLOSURE_COL_TABLENAME
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= idx<<8;
      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
      pIdxInfo->aConstraintUsage[i].omit = 1;
    }
    if( (iPlan & 0x00f000)==0
     && pConstraint->iColumn==CLOSURE_COL_IDCOLUMN
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= idx<<12;
      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
      pIdxInfo->aConstraintUsage[i].omit = 1;
    }
    if( (iPlan & 0x0f0000)==0
     && pConstraint->iColumn==CLOSURE_COL_PARENTCOLUMN
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= idx<<16;
      pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
      pIdxInfo->aConstraintUsage[i].omit = 1;
    }
  }
  if( (pVtab->zTableName==0    && (iPlan & 0x000f00)==0)
   || (pVtab->zIdColumn==0     && (iPlan & 0x00f000)==0)
   || (pVtab->zParentColumn==0 && (iPlan & 0x0f0000)==0)
  ){
    /* All of tablename, idcolumn, and parentcolumn must be specified
    ** in either the CREATE VIRTUAL TABLE or in the WHERE clause constraints
    ** or else the result is an empty set. */
    iPlan = 0;
  }
  pIdxInfo->idxNum = iPlan;
  if( pIdxInfo->nOrderBy==1
   && pIdxInfo->aOrderBy[0].iColumn==CLOSURE_COL_ID
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }
  pIdxInfo->estimatedCost = (double)10000;
   
  return SQLITE_OK;
}

/*
** A virtual table module that implements the "approximate_match".
*/
static sqlite3_module closureModule = {
  0,                      /* iVersion */
  closureConnect,         /* xCreate */
  closureConnect,         /* xConnect */
  closureBestIndex,       /* xBestIndex */
  closureDisconnect,      /* xDisconnect */
  closureDisconnect,      /* xDestroy */
  closureOpen,            /* xOpen - open a cursor */
  closureClose,           /* xClose - close a cursor */
  closureFilter,          /* xFilter - configure scan constraints */
  closureNext,            /* xNext - advance a cursor */
  closureEof,             /* xEof - check for end of scan */
  closureColumn,          /* xColumn - read data */
  closureRowid,           /* xRowid - read data */
  0,                      /* xUpdate */
  0,                      /* xBegin */
  0,                      /* xSync */
  0,                      /* xCommit */
  0,                      /* xRollback */
  0,                      /* xFindMethod */
  0,                      /* xRename */
  0,                      /* xSavepoint */
  0,                      /* xRelease */
  0                       /* xRollbackTo */
};

/*
** Register the closure virtual table
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_closure_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;
  rc = sqlite3_create_module(db, "transitive_closure", &closureModule, 0);
  return rc;
}

**
** LIMITS
**
** The maximum ruleset number is 2147483647.  The maximum length of either
** of the strings in the second or third column of the fuzzer data table
** is 50 bytes.  The maximum cost on a rule is 1000.
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

/* If SQLITE_DEBUG is not defined, disable assert statements. */
#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
# define NDEBUG
#endif


#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

  0,                           /* xFindMethod */
  0,                           /* xRename */
};

#endif /* SQLITE_OMIT_VIRTUALTABLE */







#ifdef _WIN32

__declspec(dllexport)
#endif


int sqlite3_fuzzer_init(



  sqlite3 *db, 


  char **pzErrMsg, 




  const sqlite3_api_routines *pApi



){







  int rc = SQLITE_OK;

  SQLITE_EXTENSION_INIT2(pApi);
  rc = sqlite3_create_module(db, "fuzzer", &fuzzerModule, 0);
















  return rc;
}

/*
** 2013-04-17
**
** 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 SQLite extension implements functions for the exact display
** and input of IEEE754 Binary64 floating-point numbers.
**
**   ieee754(X)
**   ieee754(Y,Z)
**
** In the first form, the value X should be a floating-point number.
** The function will return a string of the form 'ieee754(Y,Z)' where
** Y and Z are integers such that X==Y*pow(w.0,Z).
**
** In the second form, Y and Z are integers which are the mantissa and
** base-2 exponent of a new floating point number.  The function returns
** a floating-point value equal to Y*pow(2.0,Z).
**
** Examples:
**
**     ieee754(2.0)       ->     'ieee754(2,0)'
**     ieee754(45.25)     ->     'ieee754(181,-2)'
**     ieee754(2, 0)      ->     2.0
**     ieee754(181, -2)   ->     45.25
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

/*
** Implementation of the ieee754() function
*/
static void ieee754func(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  if( argc==1 ){
    sqlite3_int64 m, a;
    double r;
    int e;
    int isNeg;
    char zResult[100];
    assert( sizeof(m)==sizeof(r) );
    if( sqlite3_value_type(argv[0])!=SQLITE_FLOAT ) return;
    r = sqlite3_value_double(argv[0]);
    if( r<0.0 ){
      isNeg = 1;
      r = -r;
    }else{
      isNeg = 0;
    }
    memcpy(&a,&r,sizeof(a));
    if( a==0 ){
      e = 0;
      m = 0;
    }else{
      e = a>>52;
      m = a & ((((sqlite3_int64)1)<<52)-1);
      m |= ((sqlite3_int64)1)<<52;
      while( e<1075 && m>0 && (m&1)==0 ){
        m >>= 1;
        e++;
      }
      if( isNeg ) m = -m;
    }
    sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
                     m, e-1075);
    sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
  }else if( argc==2 ){
    sqlite3_int64 m, e, a;
    double r;
    int isNeg = 0;
    m = sqlite3_value_int64(argv[0]);
    e = sqlite3_value_int64(argv[1]);
    if( m<0 ){
      isNeg = 1;
      m = -m;
      if( m<0 ) return;
    }else if( m==0 && e>1000 && e<1000 ){
      sqlite3_result_double(context, 0.0);
      return;
    }
    while( (m>>32)&0xffe00000 ){
      m >>= 1;
      e++;
    }
    while( ((m>>32)&0xfff00000)==0 ){
      m <<= 1;
      e--;
    }
    e += 1075;
    if( e<0 ) e = m = 0;
    if( e>0x7ff ) m = 0;
    a = m & ((((sqlite3_int64)1)<<52)-1);
    a |= e<<52;
    if( isNeg ) a |= ((sqlite3_int64)1)<<63;
    memcpy(&r, &a, sizeof(r));
    sqlite3_result_double(context, r);
  }
}


#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_ieee_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "ieee754", 1, SQLITE_UTF8, 0,
                               ieee754func, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "ieee754", 2, SQLITE_UTF8, 0,
                                 ieee754func, 0, 0);
  }
  return rc;
}

/*
** 2013-02-28
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code to implement the next_char(A,T,F,W) SQL function.
**
** The next_char(A,T,F,H) function finds all valid "next" characters for
** string A given the vocabulary in T.F.  The T.F field should be indexed.
** If the W value exists and is a non-empty string, then it is an SQL
** expression that limits the entries in T.F that will be considered.
**
** For example, suppose an application has a dictionary like this:
**
**   CREATE TABLE dictionary(word TEXT UNIQUE);
**
** Further suppose that for user keypad entry, it is desired to disable
** (gray out) keys that are not valid as the next character.  If the
** the user has previously entered (say) 'cha' then to find all allowed
** next characters (and thereby determine when keys should not be grayed
** out) run the following query:
**
**   SELECT next_char('cha','dictionary','word');
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <string.h>

/*
** A structure to hold context of the next_char() computation across
** nested function calls.
*/
typedef struct nextCharContext nextCharContext;
struct nextCharContext {
  sqlite3 *db;                      /* Database connection */
  sqlite3_stmt *pStmt;              /* Prepared statement used to query */
  const unsigned char *zPrefix;     /* Prefix to scan */
  int nPrefix;                      /* Size of zPrefix in bytes */
  int nAlloc;                       /* Space allocated to aResult */
  int nUsed;                        /* Space used in aResult */
  unsigned int *aResult;            /* Array of next characters */
  int mallocFailed;                 /* True if malloc fails */
  int otherError;                   /* True for any other failure */
};

/*
** Append a result character if the character is not already in the
** result.
*/
static void nextCharAppend(nextCharContext *p, unsigned c){
  int i;
  for(i=0; i<p->nUsed; i++){
    if( p->aResult[i]==c ) return;
  }
  if( p->nUsed+1 > p->nAlloc ){
    unsigned int *aNew;
    int n = p->nAlloc*2 + 30;
    aNew = sqlite3_realloc(p->aResult, n*sizeof(unsigned int));
    if( aNew==0 ){
      p->mallocFailed = 1;
      return;
    }else{
      p->aResult = aNew;
      p->nAlloc = n;
    }
  }
  p->aResult[p->nUsed++] = c;
}

/*
** Write a character into z[] as UTF8.  Return the number of bytes needed
** to hold the character
*/
static int writeUtf8(unsigned char *z, unsigned c){
  if( c<0x00080 ){
    z[0] = (unsigned char)(c&0xff);
    return 1;
  }
  if( c<0x00800 ){
    z[0] = 0xC0 + (unsigned char)((c>>6)&0x1F);
    z[1] = 0x80 + (unsigned char)(c & 0x3F);
    return 2;
  }
  if( c<0x10000 ){
    z[0] = 0xE0 + (unsigned char)((c>>12)&0x0F);
    z[1] = 0x80 + (unsigned char)((c>>6) & 0x3F);
    z[2] = 0x80 + (unsigned char)(c & 0x3F);
    return 3;
  }
  z[0] = 0xF0 + (unsigned char)((c>>18) & 0x07);
  z[1] = 0x80 + (unsigned char)((c>>12) & 0x3F);
  z[2] = 0x80 + (unsigned char)((c>>6) & 0x3F);
  z[3] = 0x80 + (unsigned char)(c & 0x3F);
  return 4;
}

/*
** Read a UTF8 character out of z[] and write it into *pOut.  Return
** the number of bytes in z[] that were used to construct the character.
*/
static int readUtf8(const unsigned char *z, unsigned *pOut){
  static const unsigned char validBits[] = {
    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,
  };
  unsigned c = z[0];
  if( c<0xc0 ){
    *pOut = c;
    return 1;
  }else{
    int n = 1;
    c = validBits[c-0xc0];
    while( (z[n] & 0xc0)==0x80 ){
      c = (c<<6) + (0x3f & z[n++]);
    }
    if( c<0x80 || (c&0xFFFFF800)==0xD800 || (c&0xFFFFFFFE)==0xFFFE ){
      c = 0xFFFD;
    }
    *pOut = c;
    return n;
  }
}

/*
** The nextCharContext structure has been set up.  Add all "next" characters
** to the result set.
*/
static void findNextChars(nextCharContext *p){
  unsigned cPrev = 0;
  unsigned char zPrev[8];
  int n, rc;
  
  for(;;){
    sqlite3_bind_text(p->pStmt, 1, (char*)p->zPrefix, p->nPrefix,
                      SQLITE_STATIC);
    n = writeUtf8(zPrev, cPrev+1);
    sqlite3_bind_text(p->pStmt, 2, (char*)zPrev, n, SQLITE_STATIC);
    rc = sqlite3_step(p->pStmt);
    if( rc==SQLITE_DONE ){
      sqlite3_reset(p->pStmt);
      return;
    }else if( rc!=SQLITE_ROW ){
      p->otherError = rc;
      return;
    }else{
      const unsigned char *zOut = sqlite3_column_text(p->pStmt, 0);
      unsigned cNext;
      n = readUtf8(zOut+p->nPrefix, &cNext);
      sqlite3_reset(p->pStmt);
      nextCharAppend(p, cNext);
      cPrev = cNext;
      if( p->mallocFailed ) return;
    }
  }
}


/*
** next_character(A,T,F,W)
**
** Return a string composted of all next possible characters after
** A for elements of T.F.  If W is supplied, then it is an SQL expression
** that limits the elements in T.F that are considered.
*/
static void nextCharFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  nextCharContext c;
  const unsigned char *zTable = sqlite3_value_text(argv[1]);
  const unsigned char *zField = sqlite3_value_text(argv[2]);
  const unsigned char *zWhere;
  char *zSql;
  int rc;

  memset(&c, 0, sizeof(c));
  c.db = sqlite3_context_db_handle(context);
  c.zPrefix = sqlite3_value_text(argv[0]);
  c.nPrefix = sqlite3_value_bytes(argv[0]);
  if( zTable==0 || zField==0 || c.zPrefix==0 ) return;
  if( argc<4
   || (zWhere = sqlite3_value_text(argv[3]))==0
   || zWhere[0]==0
  ){
    zSql = sqlite3_mprintf(
        "SELECT \"%w\" FROM \"%w\""
        " WHERE \"%w\">=(?1 || ?2)"
        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
        " ORDER BY 1 ASC LIMIT 1",
        zField, zTable, zField, zField);
  }else{
    zSql = sqlite3_mprintf(
        "SELECT \"%w\" FROM \"%w\""
        " WHERE \"%w\">=(?1 || ?2)"
        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
        "   AND (%s)"
        " ORDER BY 1 ASC LIMIT 1",
        zField, zTable, zField, zField, zWhere);
  }
  if( zSql==0 ){
    sqlite3_result_error_nomem(context);
    return;
  }

  rc = sqlite3_prepare_v2(c.db, zSql, -1, &c.pStmt, 0);
  sqlite3_free(zSql);
  if( rc ){
    sqlite3_result_error(context, sqlite3_errmsg(c.db), -1);
    return;
  }
  findNextChars(&c);
  if( c.mallocFailed ){
    sqlite3_result_error_nomem(context);
  }else{
    unsigned char *pRes;
    pRes = sqlite3_malloc( c.nUsed*4 + 1 );
    if( pRes==0 ){
      sqlite3_result_error_nomem(context);
    }else{
      int i;
      int n = 0;
      for(i=0; i<c.nUsed; i++){
        n += writeUtf8(pRes+n, c.aResult[i]);
      }
      pRes[n] = 0;
      sqlite3_result_text(context, (const char*)pRes, n, sqlite3_free);
    }
  }
  sqlite3_finalize(c.pStmt);
  sqlite3_free(c.aResult);
}

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_nextchar_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  rc = sqlite3_create_function(db, "next_char", 3, SQLITE_UTF8, 0,
                               nextCharFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "next_char", 4, SQLITE_UTF8, 0,
                                 nextCharFunc, 0, 0);
  }
  return rc;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** The code in this file implements a compact but reasonably
** efficient regular-expression matcher for posix extended regular
** expressions against UTF8 text.
**
** This file is an SQLite extension.  It registers a single function
** named "regexp(A,B)" where A is the regular expression and B is the
** string to be matched.  By registering this function, SQLite will also
** then implement the "B regexp A" operator.  Note that with the function
** the regular expression comes first, but with the operator it comes
** second.
**
**  The following regular expression syntax is supported:
**
**     X*      zero or more occurrences of X
**     X+      one or more occurrences of X
**     X?      zero or one occurrences of X
**     X{p,q}  between p and q occurrences of X
**     (X)     match X
**     X|Y     X or Y

** exhibits exponential behavior.  Note that the X{p,q} operator expands
** to p copies of X following by q-p copies of X? and that the size of the
** regular expression in the O(N*M) performance bound is computed after
** this expansion.
*/
#include <string.h>
#include <stdlib.h>
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

/*
** The following #defines change the names of some functions implemented in
** this file to prevent name collisions with C-library functions of the
** same name.
*/
#define re_match   sqlite3re_match
#define re_compile sqlite3re_compile
#define re_free    sqlite3re_free

/* The end-of-input character */
#define RE_EOF            0    /* End of input */

/* The NFA is implemented as sequence of opcodes taken from the following
** set.  Each opcode has a single integer argument.
*/

static int re_space_char(int c){
  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
}

/* Run a compiled regular expression on the zero-terminated input
** string zIn[].  Return true on a match and false if there is no match.
*/
static int re_match(ReCompiled *pRe, const unsigned char *zIn, int nIn){
  ReStateSet aStateSet[2], *pThis, *pNext;
  ReStateNumber aSpace[100];
  ReStateNumber *pToFree;
  unsigned int i = 0;
  unsigned int iSwap = 0;
  int c = RE_EOF+1;
  int cPrev = 0;

  zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
  if( zStr!=0 ){
    sqlite3_result_int(context, re_match(pRe, zStr, -1));
  }
}

/*
** Invoke this routine to register the regexp() function with the
** SQLite database connection.







*/







#ifdef _WIN32
__declspec(dllexport)

#endif


int sqlite3_regexp_init(

  sqlite3 *db, 
  char **pzErrMsg, 

  const sqlite3_api_routines *pApi

){







  int rc = SQLITE_OK;

  SQLITE_EXTENSION_INIT2(pApi);



  rc = sqlite3_create_function(db, "regexp", 2, SQLITE_UTF8, 0,
                                 re_sql_func, 0, 0);
  return rc;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This module implements the spellfix1 VIRTUAL TABLE that can be used
** to search a large vocabulary for close matches.  See separate
** documentation (http://www.sqlite.org/spellfix1.html) for details.
*/

#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

#ifndef SQLITE_AMALGAMATION
# include <string.h>
# include <stdio.h>
# include <stdlib.h>

# include <assert.h>
# define ALWAYS(X)  1
# define NEVER(X)   0
  typedef unsigned char u8;
  typedef unsigned short u16;


# include <ctype.h>
#endif

/*
** 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 W

  for(i=0; i<sizeof(translit)/sizeof(translit[0])-1; i++){
    assert( translit[i].cFrom<translit[i+1].cFrom );
  }

  return rc;
}












/*
** Extension load function.
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_spellfix_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return spellfix1Register(db);
}

**     CREATE VIRTUAL TABLE nums USING wholenumber;
**     SELECT value FROM nums WHERE value<10;
**
** Results in:
**
**     1 2 3 4 5 6 7 8 9
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE


/* A wholenumber cursor object */

  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
};

#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef _WIN32

__declspec(dllexport)
#endif
int sqlite3_wholenumber_init(

  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3_create_module(db, "wholenumber", &wholenumberModule, 0);
#endif
  return rc;
}

# This file contains suggested magic(5) text for the unix file(1)
# utility for recognizing SQLite3 databases.
#
# When SQLite is used as an application file format, it is desirable to
# have file(1) recognize the database file as being with the specific
# application.  You can set the application_id for a database file
# using:
#
#     PRAGMA application_id = INTEGER;
#
# INTEGER can be any signed 32-bit integer.  That integer is written as
# a 4-byte big-endian integer into offset 68 of the database header. 
#
# The Monotone application used "PRAGMA user_version=1598903374;" to set
# its identifier long before "PRAGMA application_id" became available.
# The user_version is very similar to application_id except that it is
# stored at offset 68 instead of offset 60.  The application_id pragma
# is preferred.  The rule using offset 60 for Monotone is for historical
# compatibility only.
#
0    string  =SQLite\ format\ 3
>68  belong  =0x0f055111  Fossil repository -
>68  belong  =0x0f055112  Fossil checkout - 
>68  belong  =0x0f055113  Fossil global configuration - 
>60  belong  =0x5f4d544e  Monotone source repository -
>0   string  =SQLite      SQLite3 database

  $(TOP)/src/test_backup.c \
  $(TOP)/src/test_btree.c \
  $(TOP)/src/test_config.c \
  $(TOP)/src/test_demovfs.c \
  $(TOP)/src/test_devsym.c \
  $(TOP)/src/test_fs.c \
  $(TOP)/src/test_func.c \

  $(TOP)/src/test_hexio.c \
  $(TOP)/src/test_init.c \
  $(TOP)/src/test_intarray.c \
  $(TOP)/src/test_journal.c \
  $(TOP)/src/test_malloc.c \
  $(TOP)/src/test_multiplex.c \
  $(TOP)/src/test_mutex.c \
  $(TOP)/src/test_onefile.c \
  $(TOP)/src/test_osinst.c \
  $(TOP)/src/test_pcache.c \
  $(TOP)/src/test_quota.c \

  $(TOP)/src/test_rtree.c \
  $(TOP)/src/test_schema.c \
  $(TOP)/src/test_server.c \
  $(TOP)/src/test_stat.c \
  $(TOP)/src/test_sqllog.c \
  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_wsd.c

# Extensions to be statically loaded.
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/fuzzer.c \
  $(TOP)/ext/misc/ieee754.c \
  $(TOP)/ext/misc/nextchar.c \
  $(TOP)/ext/misc/regexp.c \
  $(TOP)/ext/misc/spellfix.c \
  $(TOP)/ext/misc/wholenumber.c


#TESTSRC += $(TOP)/ext/fts2/fts2_tokenizer.c
#TESTSRC += $(TOP)/ext/fts3/fts3_tokenizer.c

TESTSRC2 = \
  $(TOP)/src/attach.c \
  $(TOP)/src/backup.c \

#define BTREE_SCHEMA_VERSION      1
#define BTREE_FILE_FORMAT         2
#define BTREE_DEFAULT_CACHE_SIZE  3
#define BTREE_LARGEST_ROOT_PAGE   4
#define BTREE_TEXT_ENCODING       5
#define BTREE_USER_VERSION        6
#define BTREE_INCR_VACUUM         7
#define BTREE_APPLICATION_ID      8

/*
** Values that may be OR'd together to form the second argument of an
** sqlite3BtreeCursorHints() call.
*/
#define BTREE_BULKLOAD 0x00000001

static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  pWalker->u.i = 0;
  return WRC_Abort;
}
static int exprIsConst(Expr *p, int initFlag){
  Walker w;
  memset(&w, 0, sizeof(w));
  w.u.i = initFlag;
  w.xExprCallback = exprNodeIsConstant;
  w.xSelectCallback = selectNodeIsConstant;
  sqlite3WalkExpr(&w, p);
  return w.u.i;
}

** obtained for queries regardless of whether or not constants are
** precomputed into registers or if they are inserted in-line.
*/
void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
  Walker w;
  if( pParse->cookieGoto ) return;
  if( OptimizationDisabled(pParse->db, SQLITE_FactorOutConst) ) return;
  memset(&w, 0, sizeof(w));
  w.xExprCallback = evalConstExpr;

  w.pParse = pParse;
  sqlite3WalkExpr(&w, pExpr);
}


/*
** Generate code that pushes the value of every element of the given

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>
#if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
#include <sys/mman.h>
#endif


#if SQLITE_ENABLE_LOCKING_STYLE
# include <sys/ioctl.h>
# if OS_VXWORKS

  }else{
    pFile->lastErrno = 0; /* not a system error */
    /* Unread parts of the buffer must be zero-filled */
    memset(&((char*)pBuf)[got], 0, amt-got);
    return SQLITE_IOERR_SHORT_READ;
  }
}

/*
** Attempt to seek the file-descriptor passed as the first argument to
** absolute offset iOff, then attempt to write nBuf bytes of data from
** pBuf to it. If an error occurs, return -1 and set *piErrno. Otherwise, 
** return the actual number of bytes written (which may be less than
** nBuf).
*/
static int seekAndWriteFd(
  int fd,                         /* File descriptor to write to */
  i64 iOff,                       /* File offset to begin writing at */
  const void *pBuf,               /* Copy data from this buffer to the file */
  int nBuf,                       /* Size of buffer pBuf in bytes */
  int *piErrno                    /* OUT: Error number if error occurs */
){
  int rc = 0;                     /* Value returned by system call */

  assert( nBuf==(nBuf&0x1ffff) );
  nBuf &= 0x1ffff;
  TIMER_START;

#if defined(USE_PREAD)
  do{ rc = osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );
#elif defined(USE_PREAD64)
  do{ rc = osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);
#else
  do{
    i64 iSeek = lseek(fd, iOff, SEEK_SET);
    SimulateIOError( iSeek-- );

    if( iSeek!=iOff ){
      if( piErrno ) *piErrno = (iSeek==-1 ? errno : 0);
      return -1;
    }
    rc = osWrite(fd, pBuf, nBuf);
  }while( rc<0 && errno==EINTR );
#endif

  TIMER_END;
  OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", fd, rc, iOff, TIMER_ELAPSED));

  if( rc<0 && piErrno ) *piErrno = errno;
  return rc;
}


/*
** Seek to the offset in id->offset then read cnt bytes into pBuf.
** Return the number of bytes actually read.  Update the offset.
**
** To avoid stomping the errno value on a failed write the lastErrno value
** is set before returning.
*/
static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){






























  return seekAndWriteFd(id->h, offset, pBuf, cnt, &id->lastErrno);


}


/*
** Write data from a buffer into a file.  Return SQLITE_OK on success
** or some other error code on failure.
*/

        rc = SQLITE_IOERR_SHMSIZE;
        goto shmpage_out;
      }
  
      if( sStat.st_size<nByte ){
        /* The requested memory region does not exist. If bExtend is set to
        ** false, exit early. *pp will be set to NULL and SQLITE_OK returned.



        */
        if( !bExtend ){




          goto shmpage_out;
        }

        /* Alternatively, if bExtend is true, extend the file. Do this by
        ** writing a single byte to the end of each (OS) page being
        ** allocated or extended. Technically, we need only write to the
        ** last page in order to extend the file. But writing to all new
        ** pages forces the OS to allocate them immediately, which reduces
        ** the chances of SIGBUS while accessing the mapped region later on.
        */
        else{
          static const int pgsz = 4096;
          int iPg;

          /* Write to the last byte of each newly allocated or extended page */
          assert( (nByte % pgsz)==0 );
          for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){
            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, 0)!=1 ){
              const char *zFile = pShmNode->zFilename;
              rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);

              goto shmpage_out;
            }

          }
        }
      }
    }

    /* Map the requested memory region into this processes address space. */
    apNew = (char **)sqlite3_realloc(
        pShmNode->apRegion, (iRegion+1)*sizeof(char *)
    );

  
  pNew->lastErrno = 0;
#if OS_VXWORKS
  if( rc!=SQLITE_OK ){
    if( h>=0 ) robust_close(pNew, h, __LINE__);
    h = -1;
    osUnlink(zFilename);
    pNew->ctrlFlags |= UNIXFILE_DELETE;
  }

#endif
  if( rc!=SQLITE_OK ){
    if( h>=0 ) robust_close(pNew, h, __LINE__);
  }else{
    pNew->pMethod = pLockingStyle;
    OpenCounter(+1);
    verifyDbFile(pNew);

  if( NEVER(!isOpen(pPager->fd)) ){
    assert( pPager->tempFile );
    memset(pPg->pData, 0, pPager->pageSize);
    return SQLITE_OK;
  }

#ifndef SQLITE_OMIT_WAL
  if( iFrame ){
    /* Try to pull the page from the write-ahead log. */
    rc = sqlite3WalReadFrame(pPager->pWal, iFrame, pgsz, pPg->pData);
  }else
#endif
  {
    i64 iOffset = (pgno-1)*(i64)pPager->pageSize;
    rc = sqlite3OsRead(pPager->fd, pPg->pData, pgsz, iOffset);
    if( rc==SQLITE_IOERR_SHORT_READ ){
      rc = SQLITE_OK;
    }
  }

        assert( pPager->dbFileSize>0 );
        CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM, zBuf);
        if( rc==SQLITE_OK ){
          rc = sqlite3OsWrite(pPager->fd, zBuf, pPager->pageSize, 0);
          pPager->aStat[PAGER_STAT_WRITE]++;
        }
        if( rc==SQLITE_OK ){
          /* Update the pager's copy of the change-counter. Otherwise, the
          ** next time a read transaction is opened the cache will be
          ** flushed (as the change-counter values will not match).  */
          const void *pCopy = (const void *)&((const char *)zBuf)[24];
          memcpy(&pPager->dbFileVers, pCopy, sizeof(pPager->dbFileVers));
          pPager->changeCountDone = 1;
        }
      }else{
        pPager->changeCountDone = 1;
      }
    }

    }else if( F->nSrc==1 ){
      A = sqlite3SrcListAppendFromTerm(pParse,X,0,0,&Z,0,N,U);
      if( A ){
        struct SrcList_item *pNew = &A->a[A->nSrc-1];
        struct SrcList_item *pOld = F->a;
        pNew->zName = pOld->zName;
        pNew->zDatabase = pOld->zDatabase;
        pNew->pSelect = pOld->pSelect;
        pOld->zName = pOld->zDatabase = 0;
        pOld->pSelect = 0;
      }
      sqlite3SrcListDelete(pParse->db, F);
    }else{
      Select *pSubquery;
      sqlite3SrcListShiftJoinType(F);
      pSubquery = sqlite3SelectNew(pParse,0,F,0,0,0,0,SF_NestedFrom,0,0);
      A = sqlite3SrcListAppendFromTerm(pParse,X,0,0,&Z,pSubquery,N,U);

#ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
  /*
  **   PRAGMA [database.]schema_version
  **   PRAGMA [database.]schema_version = <integer>
  **
  **   PRAGMA [database.]user_version
  **   PRAGMA [database.]user_version = <integer>
  **
  **   PRAGMA [database.]freelist_count = <integer>
  **
  **   PRAGMA [database.]application_id
  **   PRAGMA [database.]application_id = <integer>
  **
  ** The pragma's schema_version and user_version are used to set or get
  ** the value of the schema-version and user-version, respectively. Both
  ** the schema-version and the user-version are 32-bit signed integers
  ** stored in the database header.
  **
  ** The schema-cookie is usually only manipulated internally by SQLite. It

  **
  ** The user-version is not used internally by SQLite. It may be used by
  ** applications for any purpose.
  */
  if( sqlite3StrICmp(zLeft, "schema_version")==0 
   || sqlite3StrICmp(zLeft, "user_version")==0 
   || sqlite3StrICmp(zLeft, "freelist_count")==0 
   || sqlite3StrICmp(zLeft, "application_id")==0 
  ){
    int iCookie;   /* Cookie index. 1 for schema-cookie, 6 for user-cookie. */
    sqlite3VdbeUsesBtree(v, iDb);
    switch( zLeft[0] ){
      case 'a': case 'A':
        iCookie = BTREE_APPLICATION_ID;
        break;
      case 'f': case 'F':
        iCookie = BTREE_FREE_PAGE_COUNT;
        break;
      case 's': case 'S':
        iCookie = BTREE_SCHEMA_VERSION;
        break;
      default:

      return 1;
    }
    pParse->nHeight += pExpr->nHeight;
  }
#endif
  savedHasAgg = pNC->ncFlags & NC_HasAgg;
  pNC->ncFlags &= ~NC_HasAgg;
  memset(&w, 0, sizeof(w));
  w.xExprCallback = resolveExprStep;
  w.xSelectCallback = resolveSelectStep;
  w.pParse = pNC->pParse;
  w.u.pNC = pNC;
  sqlite3WalkExpr(&w, pExpr);
#if SQLITE_MAX_EXPR_DEPTH>0
  pNC->pParse->nHeight -= pExpr->nHeight;

  Parse *pParse,         /* The parser context */
  Select *p,             /* The SELECT statement being coded. */
  NameContext *pOuterNC  /* Name context for parent SELECT statement */
){
  Walker w;

  assert( p!=0 );
  memset(&w, 0, sizeof(w));
  w.xExprCallback = resolveExprStep;
  w.xSelectCallback = resolveSelectStep;
  w.pParse = pParse;
  w.u.pNC = pOuterNC;
  sqlite3WalkSelect(&w, p);
}

**
** If anything goes wrong, an error message is written into pParse.
** The calling function can detect the problem by looking at pParse->nErr
** and/or pParse->db->mallocFailed.
*/
static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
  Walker w;
  memset(&w, 0, sizeof(w));
  w.xSelectCallback = selectExpander;
  w.xExprCallback = exprWalkNoop;
  w.pParse = pParse;
  sqlite3WalkSelect(&w, pSelect);
}

** SELECT statement.
**
** Use this routine after name resolution.
*/
static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
#ifndef SQLITE_OMIT_SUBQUERY
  Walker w;
  memset(&w, 0, sizeof(w));
  w.xSelectCallback = selectAddSubqueryTypeInfo;
  w.xExprCallback = exprWalkNoop;
  w.pParse = pParse;
  w.bSelectDepthFirst = 1;
  sqlite3WalkSelect(&w, pSelect);
#endif
}


/*
** This routine sets up a SELECT statement for processing.  The

      int retAddr;
      assert( pItem->addrFillSub==0 );
      pItem->regReturn = ++pParse->nMem;
      topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
      pItem->addrFillSub = topAddr+1;
      VdbeNoopComment((v, "materialize %s", pItem->pTab->zName));
      if( pItem->isCorrelated==0 ){
        /* If the subquery is not correlated and if we are not inside of
        ** a trigger, then we only need to compute the value of the subquery
        ** once. */
        onceAddr = sqlite3CodeOnce(pParse);
      }
      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
      sqlite3Select(pParse, pSub, &dest);

    if( db==0 || SQLITE_OK!=sqlite3_errcode(db) ){
      fprintf(stderr,"Error: unable to open database \"%s\": %s\n", 
          p->zDbFilename, sqlite3_errmsg(db));
      exit(1);
    }
#ifndef SQLITE_OMIT_LOAD_EXTENSION
    sqlite3_enable_load_extension(p->db, 1);












#endif
  }
}

/*
** Do C-language style dequoting.
**

**
** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** [sqlite3_pcache_methods2] object.  SQLite copies of the current
** page cache implementation into that object.)^ </dd>
**
** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
** global [error log].
** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
** function with a call signature of void(*)(void*,int,const char*), 
** and a pointer to void. ^If the function pointer is not NULL, it is
** invoked by [sqlite3_log()] to process each logging event.  ^If the
** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
** passed through as the first parameter to the application-defined logger
** function whenever that function is invoked.  ^The second parameter to

** various times when an SQL statement is being run by [sqlite3_step()].
** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
** SQL statement text as the statement first begins executing.
** ^(Additional sqlite3_trace() callbacks might occur
** as each triggered subprogram is entered.  The callbacks for triggers
** contain a UTF-8 SQL comment that identifies the trigger.)^
**
** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
** the length of [bound parameter] expansion in the output of sqlite3_trace().
**
** ^The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  ^The profile callback contains
** the original statement text and an estimate of wall-clock time
** of how long that statement took to run.  ^The profile callback
** time is in units of nanoseconds, however the current implementation
** is only capable of millisecond resolution so the six least significant
** digits in the time are meaningless.  Future versions of SQLite

** original SQL text. This causes the [sqlite3_step()] interface to
** behave differently in three ways:
**
** <ol>
** <li>
** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
** always used to do, [sqlite3_step()] will automatically recompile the SQL
** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
** retries will occur before sqlite3_step() gives up and returns an error.
** </li>
**
** <li>
** ^When an error occurs, [sqlite3_step()] will return one of the detailed
** [error codes] or [extended error codes].  ^The legacy behavior was that
** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
** and the application would have to make a second call to [sqlite3_reset()]

** ^The index for named parameters can be looked up using the
** [sqlite3_bind_parameter_index()] API if desired.  ^The index
** for "?NNN" parameters is the value of NNN.
** ^The NNN value must be between 1 and the [sqlite3_limit()]
** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
**
** ^The third argument is the value to bind to the parameter.
** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
** is ignored and the end result is the same as sqlite3_bind_null().
**
** ^(In those routines that have a fourth argument, its value is the
** number of bytes in the parameter.  To be clear: the value is the
** number of <u>bytes</u> in the value, not the number of characters.)^
** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
** is negative, then the length of the string is
** the number of bytes up to the first zero terminator.

** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
*/
int sqlite3_strglob(const char *zGlob, const char *zStr);

/*
** CAPI3REF: Error Logging Interface
**
** ^The [sqlite3_log()] interface writes a message into the [error log]
** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
** ^If logging is enabled, the zFormat string and subsequent arguments are
** used with [sqlite3_snprintf()] to generate the final output string.
**
** The sqlite3_log() interface is intended for use by extensions such as
** virtual tables, collating functions, and SQL functions.  While there is
** nothing to prevent an application from calling sqlite3_log(), doing so

# endif
#endif
#ifndef SQLITE_MAX_MMAP_SIZE
# if defined(__linux__) \
  || defined(_WIN32) \
  || (defined(__APPLE__) && defined(__MACH__)) \
  || defined(__sun)
#   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */
# else
#   define SQLITE_MAX_MMAP_SIZE 0
# endif
# define SQLITE_MAX_MMAP_SIZE_xc 1 /* exclude from ctime.c */
#endif

/*

** Context pointer passed down through the tree-walk.
*/
struct Walker {
  int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
  int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
  Parse *pParse;                            /* Parser context.  */
  int walkerDepth;                          /* Number of subqueries */
  u8 bSelectDepthFirst;                     /* Do subqueries first */
  union {                                   /* Extra data for callback */
    NameContext *pNC;                          /* Naming context */
    int i;                                     /* Integer value */
    SrcList *pSrcList;                         /* FROM clause */
    struct SrcCount *pSrcCount;                /* Counting column references */
  } u;
};

    extern int Sqlitetestintarray_Init(Tcl_Interp*);
    extern int Sqlitetestvfs_Init(Tcl_Interp *);
    extern int Sqlitetestrtree_Init(Tcl_Interp*);
    extern int Sqlitequota_Init(Tcl_Interp*);
    extern int Sqlitemultiplex_Init(Tcl_Interp*);
    extern int SqliteSuperlock_Init(Tcl_Interp*);
    extern int SqlitetestSyscall_Init(Tcl_Interp*);


#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
    extern int TestSession_Init(Tcl_Interp*);
#endif


#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
    extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
#endif

#ifdef SQLITE_ENABLE_ZIPVFS
    extern int Zipvfs_Init(Tcl_Interp*);

    Sqlitetestintarray_Init(interp);
    Sqlitetestvfs_Init(interp);
    Sqlitetestrtree_Init(interp);
    Sqlitequota_Init(interp);
    Sqlitemultiplex_Init(interp);
    SqliteSuperlock_Init(interp);
    SqlitetestSyscall_Init(interp);


#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
    TestSession_Init(interp);
#endif


#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
    Sqlitetestfts3_Init(interp);
#endif

    Tcl_CreateObjCommand(
        interp, "load_testfixture_extensions", init_all_cmd, 0, 0

      Tcl_AppendResult(interp, " ", aOpt[i].zOptName);
    }
    return TCL_ERROR;
  }
  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, db, mask);
  return TCL_OK;
}

typedef struct sqlite3_api_routines sqlite3_api_routines;
/*
**     load_static_extension DB NAME ...
**
** Load one or more statically linked extensions.
*/
static int tclLoadStaticExtensionCmd(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  extern int sqlite3_amatch_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_closure_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_fuzzer_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_ieee_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_nextchar_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_regexp_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_spellfix_init(sqlite3*,char**,const sqlite3_api_routines*);
  extern int sqlite3_wholenumber_init(sqlite3*,char**,const sqlite3_api_routines*);
  static const struct {
    const char *zExtName;
    int (*pInit)(sqlite3*,char**,const sqlite3_api_routines*);
  } aExtension[] = {
    { "amatch",                sqlite3_amatch_init               },
    { "closure",               sqlite3_closure_init              },
    { "fuzzer",                sqlite3_fuzzer_init               },
    { "ieee754",               sqlite3_ieee_init                 },
    { "nextchar",              sqlite3_nextchar_init             },
    { "regexp",                sqlite3_regexp_init               },
    { "spellfix",              sqlite3_spellfix_init             },
    { "wholenumber",           sqlite3_wholenumber_init          },
  };
  sqlite3 *db;
  const char *zName;
  int i, j, rc;
  char *zErrMsg = 0;
  if( objc<3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB NAME ...");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  for(j=2; j<objc; j++){
    zName = Tcl_GetString(objv[j]);
    for(i=0; i<ArraySize(aExtension); i++){
      if( strcmp(zName, aExtension[i].zExtName)==0 ) break;
    }
    if( i>=ArraySize(aExtension) ){
      Tcl_AppendResult(interp, "no such extension: ", zName, (char*)0);
      return TCL_ERROR;
    }
    rc = aExtension[i].pInit(db, &zErrMsg, 0);
    if( rc!=SQLITE_OK || zErrMsg ){
      Tcl_AppendResult(interp, "initialization of ", zName, " failed: ", zErrMsg,
                       (char*)0);
      sqlite3_free(zErrMsg);
      return TCL_ERROR;
    }
  }
  return TCL_OK;
}


/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest1_Init(Tcl_Interp *interp){
  extern int sqlite3_search_count;
  extern int sqlite3_found_count;

#ifndef SQLITE_OMIT_EXPLAIN
     { "print_explain_query_plan", test_print_eqp, 0  },
#endif
     { "sqlite3_test_control", test_test_control },
#if SQLITE_OS_UNIX
     { "getrusage", test_getrusage },
#endif
     { "load_static_extension", tclLoadStaticExtensionCmd },
  };
  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;
  extern int sqlite3_xferopt_count;

  if( rc!=SQLITE_OK ){
    Tcl_SetResult(interp, (char *)sqlite3_errmsg(db), TCL_VOLATILE);
    return TCL_ERROR;
  }
  return TCL_OK;
}
























#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest8_Init(Tcl_Interp *interp){
#ifndef SQLITE_OMIT_VIRTUALTABLE
  static struct {
     char *zName;
     Tcl_ObjCmdProc *xProc;
     void *clientData;
  } aObjCmd[] = {
     { "register_echo_module",       register_echo_module, 0 },

     { "sqlite3_declare_vtab",       declare_vtab, 0 },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
  }

    ** connections to the same database will know to reread the schema.
    */
    static const unsigned char aCopy[] = {
       BTREE_SCHEMA_VERSION,     1,  /* Add one to the old schema cookie */
       BTREE_DEFAULT_CACHE_SIZE, 0,  /* Preserve the default page cache size */
       BTREE_TEXT_ENCODING,      0,  /* Preserve the text encoding */
       BTREE_USER_VERSION,       0,  /* Preserve the user version */
       BTREE_APPLICATION_ID,     0,  /* Preserve the application id */
    };

    assert( 1==sqlite3BtreeIsInTrans(pTemp) );
    assert( 1==sqlite3BtreeIsInTrans(pMain) );

    /* Copy Btree meta values */
    for(i=0; i<ArraySize(aCopy); i+=2){

# define sqlite3WalSavepointUndo(y,z)            0
# define sqlite3WalFrames(u,v,w,x,y,z)           0
# define sqlite3WalCheckpoint(r,s,t,u,v,w,x,y,z) 0
# define sqlite3WalCallback(z)                   0
# define sqlite3WalExclusiveMode(y,z)            0
# define sqlite3WalHeapMemory(z)                 0
# define sqlite3WalFramesize(z)                  0
# define sqlite3WalFindFrame(x,y,z)              0
#else

#define WAL_SAVEPOINT_NDATA 4

/* Connection to a write-ahead log (WAL) file. 
** There is one object of this type for each pager. 
*/

  }
  return WRC_Continue;
} 

/*
** Call sqlite3WalkExpr() for every expression in Select statement p.
** Invoke sqlite3WalkSelect() for subqueries in the FROM clause and
** on the compound select chain, p->pPrior.  Invoke the xSelectCallback()
** either before or after the walk of expressions and FROM clause, depending
** on whether pWalker->bSelectDepthFirst is false or true, respectively.
**
** Return WRC_Continue under normal conditions.  Return WRC_Abort if
** there is an abort request.
**
** If the Walker does not have an xSelectCallback() then this routine
** is a no-op returning WRC_Continue.
*/
int sqlite3WalkSelect(Walker *pWalker, Select *p){
  int rc;
  if( p==0 || pWalker->xSelectCallback==0 ) return WRC_Continue;
  rc = WRC_Continue;
  pWalker->walkerDepth++;
  while( p ){
    if( !pWalker->bSelectDepthFirst ){
       rc = pWalker->xSelectCallback(pWalker, p);
       if( rc ) break;
    }
    if( sqlite3WalkSelectExpr(pWalker, p)
     || sqlite3WalkSelectFrom(pWalker, p)
    ){
      pWalker->walkerDepth--;
      return WRC_Abort;
    }
    if( pWalker->bSelectDepthFirst ){
      rc = pWalker->xSelectCallback(pWalker, p);
      /* Depth-first search is currently only used for
      ** selectAddSubqueryTypeInfo() and that routine always returns
      ** WRC_Continue (0).  So the following branch is never taken. */
      if( NEVER(rc) ) break;
    }
    p = p->pPrior;
  }
  pWalker->walkerDepth--;
  return rc & WRC_Abort;
}

              for(j=0; pIdx->aiColumn[j]!=iOrigCol; j++){
                if( NEVER(j>=pIdx->nColumn) ) return 0;
              }
              if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ){
                continue;
              }
            }
            if( pTerm->prereqRight==0 && (pTerm->eOperator&WO_EQ)!=0 ){
              pResult = pTerm;
              goto findTerm_success;
            }else if( pResult==0 ){
              pResult = pTerm;
            }
          }
          if( (pTerm->eOperator & WO_EQUIV)!=0

    if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue;
    if( pTerm->leftCursor!=iCur ) continue;
    pE = pTerm->pExpr;
    assert( !ExprHasProperty(pE, EP_FromJoin) );
    assert( (pTerm->prereqRight & newNotReady)!=0 );
    pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
    if( pAlt==0 ) continue;
    if( pAlt->wtFlags & (TERM_CODED) ) continue;
    VdbeNoopComment((v, "begin transitive constraint"));
    sEq = *pAlt->pExpr;
    sEq.pLeft = pE->pLeft;
    sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL);
  }

  /* For a LEFT OUTER JOIN, generate code that will record the fact that

  finish_test
  return
}
db close
forcedelete test.db
do_test 8_3_names-5.0 {
  sqlite3 db file:./test.db?8_3_names=1
  load_static_extension db wholenumber
  db eval {
    PRAGMA journal_mode=WAL;
    CREATE TABLE t1(x);
    CREATE VIRTUAL TABLE nums USING wholenumber;
    INSERT INTO t1 SELECT value FROM nums WHERE value BETWEEN 1 AND 1000;
    BEGIN;
    UPDATE t1 SET x=x*2;
  }
  sqlite3 db2 file:./test.db?8_3_names=1
  load_static_extension db2 wholenumber
  db2 eval {
    BEGIN;
    SELECT sum(x) FROM t1;
  }
} {500500}

do_test 8_3_names-5.1 {

  finish_test
  return
}

# Generate some test data
#
do_test analyze7-1.0 {
  load_static_extension db wholenumber
  execsql {
    CREATE TABLE t1(a,b,c,d);
    CREATE INDEX t1a ON t1(a);
    CREATE INDEX t1b ON t1(b);
    CREATE INDEX t1cd ON t1(c,d);
    CREATE VIRTUAL TABLE nums USING wholenumber;
    INSERT INTO t1 SELECT value, value, value/100, value FROM nums

# 2013-04-25
#
# 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.
#
#***********************************************************************
# 
# Test cases for transitive_closure virtual table.

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix closure01

load_static_extension db closure

do_execsql_test 1.0 {
  BEGIN;
  CREATE TABLE t1(x INTEGER PRIMARY KEY, y INTEGER);
  CREATE INDEX t1y ON t1(y);
  INSERT INTO t1(x) VALUES(1),(2);
  INSERT INTO t1(x) SELECT x+2 FROM t1;
  INSERT INTO t1(x) SELECT x+4 FROM t1;
  INSERT INTO t1(x) SELECT x+8 FROM t1;
  INSERT INTO t1(x) SELECT x+16 FROM t1;
  INSERT INTO t1(x) SELECT x+32 FROM t1;
  INSERT INTO t1(x) SELECT x+64 FROM t1;
  INSERT INTO t1(x) SELECT x+128 FROM t1;
  INSERT INTO t1(x) SELECT x+256 FROM t1;
  INSERT INTO t1(x) SELECT x+512 FROM t1;
  INSERT INTO t1(x) SELECT x+1024 FROM t1;
  INSERT INTO t1(x) SELECT x+2048 FROM t1;
  INSERT INTO t1(x) SELECT x+4096 FROM t1;
  INSERT INTO t1(x) SELECT x+8192 FROM t1;
  INSERT INTO t1(x) SELECT x+16384 FROM t1;
  INSERT INTO t1(x) SELECT x+32768 FROM t1;
  INSERT INTO t1(x) SELECT x+65536 FROM t1;
  UPDATE t1 SET y=x/2 WHERE x>1;
  COMMIT;
  CREATE VIRTUAL TABLE cx 
   USING transitive_closure(tablename=t1, idcolumn=x, parentcolumn=y);
} {}

# The entire table
do_execsql_test 1.1 {
  SELECT count(*), depth FROM cx WHERE root=1 GROUP BY depth ORDER BY 1;
} {/1 0 1 17 2 1 4 2 8 3 16 4 .* 65536 16/}

# descendents of 32768
do_execsql_test 1.2 {
  SELECT * FROM cx WHERE root=32768 ORDER BY id;
} {32768 0 65536 1 65537 1 131072 2}

# descendents of 16384
do_execsql_test 1.3 {
  SELECT * FROM cx WHERE root=16384 AND depth<=2 ORDER BY id;
} {16384 0 32768 1 32769 1 65536 2 65537 2 65538 2 65539 2}

# children of 16384
do_execsql_test 1.4 {
  SELECT id, depth, root, tablename, idcolumn, parentcolumn FROM cx
   WHERE root=16384
     AND depth=1
   ORDER BY id;
} {32768 1 {} t1 x y 32769 1 {} t1 x y}

# great-grandparent of 16384
do_execsql_test 1.5 {
  SELECT id, depth, root, tablename, idcolumn, parentcolumn FROM cx
   WHERE root=16384
     AND depth=3
     AND idcolumn='Y'
     AND parentcolumn='X';
} {2048 3 {} t1 Y X}

# depth<5
do_execsql_test 1.6 {
  SELECT count(*), depth FROM cx WHERE root=1 AND depth<5
   GROUP BY depth ORDER BY 1;
} {1 0 2 1 4 2 8 3 16 4}

# depth<=5
do_execsql_test 1.7 {
  SELECT count(*), depth FROM cx WHERE root=1 AND depth<=5
   GROUP BY depth ORDER BY 1;
} {1 0 2 1 4 2 8 3 16 4 32 5}

# depth==5
do_execsql_test 1.8 {
  SELECT count(*), depth FROM cx WHERE root=1 AND depth=5
   GROUP BY depth ORDER BY 1;
} {32 5}

# depth BETWEEN 3 AND 5
do_execsql_test 1.9 {
  SELECT count(*), depth FROM cx WHERE root=1 AND depth BETWEEN 3 AND 5
   GROUP BY depth ORDER BY 1;
} {8 3 16 4 32 5}

# depth==5 with min() and max()
do_execsql_test 1.10 {
  SELECT count(*), min(id), max(id) FROM cx WHERE root=1 AND depth=5;
} {32 32 63}

# Create a much smaller table t2 with only 32 elements 
db eval {
  CREATE TABLE t2(x INTEGER PRIMARY KEY, y INTEGER);
  INSERT INTO t2 SELECT x, y FROM t1 WHERE x<32;
  CREATE INDEX t2y ON t2(y);
  CREATE VIRTUAL TABLE c2 
   USING transitive_closure(tablename=t2, idcolumn=x, parentcolumn=y);
}

# t2 full-table
do_execsql_test 2.1 {
  SELECT count(*), min(id), max(id) FROM c2 WHERE root=1;
} {31 1 31}
# t2 root=10
do_execsql_test 2.2 {
  SELECT id FROM c2 WHERE root=10;
} {10 20 21}
# t2 root=11
do_execsql_test 2.3 {
  SELECT id FROM c2 WHERE root=12;
} {12 24 25}
# t2 root IN [10,12]
do_execsql_test 2.4 {
  SELECT id FROM c2 WHERE root IN (10,12) ORDER BY id;
} {10 12 20 21 24 25}
# t2 root IN [10,12] (sorted)
do_execsql_test 2.5 {
  SELECT id FROM c2 WHERE root IN (10,12) ORDER BY +id;
} {10 12 20 21 24 25}

# t2 c2up from 20
do_execsql_test 3.0 {
  CREATE VIRTUAL TABLE c2up USING transitive_closure(
    tablename = t2,
    idcolumn = y,
    parentcolumn = x
  );
  SELECT id FROM c2up WHERE root=20;
} {1 2 5 10 20}

# cx as c2up
do_execsql_test 3.1 {
  SELECT id FROM cx
   WHERE root=20
     AND tablename='t2'
     AND idcolumn='y'
     AND parentcolumn='x';
} {1 2 5 10 20}

# t2 first cousins of 20
do_execsql_test 3.2 {
  SELECT DISTINCT id FROM c2
   WHERE root IN (SELECT id FROM c2up
                   WHERE root=20 AND depth<=2)
   ORDER BY id;
} {5 10 11 20 21 22 23}

# t2 first cousins of 20
do_execsql_test 3.3 {
  SELECT id FROM c2
   WHERE root=(SELECT id FROM c2up
               WHERE root=20 AND depth=2)
     AND depth=2
  EXCEPT
  SELECT id FROM c2
   WHERE root=(SELECT id FROM c2up
               WHERE root=20 AND depth=1)
     AND depth<=1
   ORDER BY id;
} {22 23}

# missing tablename.
do_test 4.1 {
  catchsql {
    SELECT id FROM cx
     WHERE root=20
       AND tablename='t3'
       AND idcolumn='y'
       AND parentcolumn='x';
  }
} {1 {no such table: t3}}

# missing idcolumn
do_test 4.2 {
  catchsql {
    SELECT id FROM cx
     WHERE root=20
       AND tablename='t2'
       AND idcolumn='xyz'
       AND parentcolumn='x';
  }
} {1 {no such column: t2.xyz}}

# missing parentcolumn
do_test 4.3 {
  catchsql {
    SELECT id FROM cx
     WHERE root=20
       AND tablename='t2'
       AND idcolumn='x'
       AND parentcolumn='pqr';
  }
} {1 {no such column: t2.pqr}}

# generic closure
do_execsql_test 5.1 {
  CREATE VIRTUAL TABLE temp.closure USING transitive_closure;
  SELECT id FROM closure
   WHERE root=1
     AND depth=3
     AND tablename='t1'
     AND idcolumn='x'
     AND parentcolumn='y'
  ORDER BY id;
} {8 9 10 11 12 13 14 15}

finish_test

# 2009 January 1
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#*************************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the part of the FTS3 expression
# parser that rebalances large expressions.
#
# $Id: fts3expr2.test,v 1.2 2009/06/05 17:09:12 drh Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl
set ::testprefix fts3expr3

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts3 {
  finish_test
  return
}

set sqlite_fts3_enable_parentheses 1

proc strip_phrase_data {L} {
  if {[lindex $L 0] eq "PHRASE"} {
    return [list P [lrange $L 3 end]]
  }
  return [list \
    [lindex $L 0] \
    [strip_phrase_data [lindex $L 1]] \
    [strip_phrase_data [lindex $L 2]] \
  ]
}
proc test_fts3expr2 {expr} {
  strip_phrase_data [
    db one {SELECT fts3_exprtest_rebalance('simple', $expr, 'a', 'b', 'c')}
  ]
}

proc balanced_exprtree_structure {nEntry} {
  set L [list]
  for {set i 1} {$i <= $nEntry} {incr i} {
    lappend L xxx
  }
  while {[llength $L] > 1} {
    set N [list]
    if {[llength $L] % 2} {
      foreach {a b} [lrange $L 0 end-1] { lappend N [list AND $a $b] }
      lappend N [lindex $L end]
    } else {
      foreach {a b} $L { lappend N [list AND $a $b] }
    }
    set L $N
  }
  return [lindex $L 0]
}

proc balanced_and_tree {nEntry} {
  set query [balanced_exprtree_structure $nEntry]
  if {$query == "xxx"} {
    return "P 1"
  }
  for {set i 1} {$i <= $nEntry} {incr i} {
    regsub xxx $query "{P $i}" query
  }
  return $query
}

proc random_tree_structure {nEntry bParen op} {
  set query xxx
  for {set i 1} {$i < $nEntry} {incr i} {
    set x1 [expr int(rand()*4.0)]
    set x2 [expr int(rand()*2.0)]
    if {$x1==0 && $bParen} {
      set query "($query)"
    }
    if {$x2} {
      set query "xxx $op $query"
    } else {
      set query "$query $op xxx"
    }
  }
  return $query
}

proc random_and_query {nEntry {bParen 0}} {
  set query [random_tree_structure $nEntry $bParen AND]
  for {set i 1} {$i <= $nEntry} {incr i} {
    regsub xxx $query $i query
  }
  return $query
}

proc random_or_query {nEntry} {
  set query [random_tree_structure $nEntry 1 OR]
  for {set i 1} {$i <= $nEntry} {incr i} {
    regsub xxx $query $i query
  }
  return $query
}

proc random_andor_query {nEntry} {
  set query [random_tree_structure $nEntry 1 AND]
  for {set i 1} {$i <= $nEntry} {incr i} {
    regsub xxx $query "([random_or_query $nEntry])" query
  }
  return $query
}

proc balanced_andor_tree {nEntry} {
  set tree [balanced_exprtree_structure $nEntry]
  set node "{[balanced_and_tree $nEntry]}"
  regsub -all AND $node OR node
  regsub -all xxx $tree $node tree
  return $tree
}

# Test that queries like "1 AND 2 AND 3 AND 4..." are transformed to 
# balanced trees by FTS.
#
for {set i 1} {$i < 100} {incr i} {
  do_test 1.$i {
    test_fts3expr2 [random_and_query $i]
  } [balanced_and_tree $i]
}

# Same again, except with parenthesis inserted at arbitrary points.
#
for {set i 1} {$i < 100} {incr i} {
  do_test 2.$i {
    test_fts3expr2 [random_and_query $i 1]
  } [balanced_and_tree $i]
}

# Now attempt to balance two AND trees joined by an OR.
#
for {set i 1} {$i < 100} {incr i} {
  do_test 3.$i {
    test_fts3expr2 "[random_and_query $i 1] OR [random_and_query $i 1]"
  } [list OR [balanced_and_tree $i] [balanced_and_tree $i]]
}

# Try trees of AND nodes with leaves that are themselves trees of OR nodes.
#
for {set i 2} {$i < 64} {incr i 4} {
  do_test 3.$i {
    test_fts3expr2 [random_andor_query $i]
  } [balanced_andor_tree $i]
}

# These exceed the depth limit. 
#
for {set i 65} {$i < 70} {incr i} {
  do_test 3.$i {
    list [catch {test_fts3expr2 [random_andor_query $i]} msg] $msg
  } {1 {Error parsing expression}}
}

# This also exceeds the depth limit. 
#

do_test 4.1.1 {
  set q "1"
  for {set i 2} {$i < 5000} {incr i} {
    append q " AND $i"
  }
  list [catch {test_fts3expr2 $q} msg] $msg
} {1 {Error parsing expression}}
do_test 4.1.2 {
  set q "1"
  for {set i 2} {$i < 4000} {incr i} {
    append q " AND $i"
  }
  catch {test_fts3expr2 $q}
} {0}

proc create_toggle_tree {nDepth} {
  if {$nDepth == 0} { return xxx }
  set nNew [expr $nDepth-1]
  if {$nDepth % 2} {
    return "([create_toggle_tree $nNew]) OR ([create_toggle_tree $nNew])"
  }
  return "([create_toggle_tree $nNew]) AND ([create_toggle_tree $nNew])"
}

do_test 4.2 {
  list [catch {test_fts3expr2 [create_toggle_tree 17]} msg] $msg
} {1 {Error parsing expression}}

set query [random_andor_query 12]
set result [balanced_andor_tree 12]
do_faultsim_test fts3expr3-fault-1 -faults oom-* -body {
  test_fts3expr2 $::query
} -test {
  faultsim_test_result [list 0 $::result]
}

set sqlite_fts3_enable_parentheses 0
finish_test

ifcapable !vtab {
  finish_test
  return
}

set ::testprefix fuzzer1





load_static_extension db fuzzer


# Check configuration errors.
#
do_catchsql_test fuzzer1-1.1 {
  CREATE VIRTUAL TABLE f USING fuzzer;
} {1 {fuzzer: wrong number of CREATE VIRTUAL TABLE arguments}}

#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable !vtab { finish_test ; return }
set ::testprefix fuzzerfault

load_static_extension db fuzzer

do_test 1-pre1 {
  execsql {
    CREATE TABLE x1_rules(ruleset, cFrom, cTo, cost);
    INSERT INTO x1_rules VALUES(0, 'a', 'b', 1);
    INSERT INTO x1_rules VALUES(0, 'a', 'c', 2);
    INSERT INTO x1_rules VALUES(0, 'a', 'd', 3);
  }
  faultsim_save_and_close
} {}
do_faultsim_test 1 -prep {
  faultsim_restore_and_reopen
  load_static_extension db fuzzer
} -body {
  execsql { 
    CREATE VIRTUAL TABLE x1 USING fuzzer(x1_rules);
    SELECT word FROM x1 WHERE word MATCH 'xax';
  }
} -test {
  faultsim_test_result {0 {xax xbx xcx xdx}}               \
                       {1 {vtable constructor failed: x1}}
}

do_test 2-pre1 {
  faultsim_delete_and_reopen
  load_static_extension db fuzzer
  execsql {
    CREATE TABLE x2_rules(ruleset, cFrom, cTo, cost);
    INSERT INTO x2_rules VALUES(0, 'a', 'x', 1);
    INSERT INTO x2_rules VALUES(0, 'b', 'x', 2);
    INSERT INTO x2_rules VALUES(0, 'c', 'x', 3);
    CREATE VIRTUAL TABLE x2 USING fuzzer(x2_rules);
  }
  faultsim_save_and_close
} {}

do_faultsim_test 2 -prep {
  faultsim_restore_and_reopen
  load_static_extension db fuzzer
} -body {
  execsql { 
    SELECT count(*) FROM x2 WHERE word MATCH 'abc';
  }
} -test {
  faultsim_test_result {0 8} {1 {vtable constructor failed: x2}}
}

    );
  }
  faultsim_save_and_close
} {}

do_faultsim_test 3 -prep {
  faultsim_restore_and_reopen
  load_static_extension db fuzzer
} -body {
  execsql { 
    CREATE VIRTUAL TABLE x1 USING fuzzer(x1_rules);
    SELECT count(*) FROM (SELECT * FROM x1 WHERE word MATCH 'a' LIMIT 2);
  }
} -test {
  faultsim_test_result {0 2} {1 {vtable constructor failed: x1}}
}


finish_test

# The focus of this file is testing some specific characteristics of the 
# IO traffic generated by SQLite (making sure SQLite is not writing out
# more database pages than it has to, stuff like that).
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix io

db close
sqlite3_simulate_device
sqlite3 db test.db -vfs devsym

# Test summary:
#

# io-4.* -  Test the IO traffic enhancements triggered when the 
#           IOCAP_SAFE_APPEND device capability flag is set (fewer 
#           fsync() calls on the journal file, no need to set nRec
#           field in the single journal header).
#
# io-5.* -  Test that the default page size is selected and used 
#           correctly.
#
# io-6.* -  Test that the pager-cache is not being flushed unnecessarily 
#           after a transaction that uses the special atomic-write path
#           is committed.
#           

set ::nWrite 0
proc nWrite {db} {
  set bt [btree_from_db $db]
  db_enter $db
  array set stats [btree_pager_stats $bt]

  do_test io-5.$tn {
    execsql {
      CREATE TABLE abc(a, b, c);
    }
    expr {[file size test.db]/2}
  } $pgsize
}

#----------------------------------------------------------------------
#
do_test io-6.1 {
  db close
  sqlite3_simulate_device -char atomic
  forcedelete test.db
  sqlite3 db test.db -vfs devsym
  execsql {
    PRAGMA mmap_size = 0;
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x);
    CREATE TABLE t2(x);
    CREATE TABLE t3(x);
    CREATE INDEX i3 ON t3(x);
    INSERT INTO t3 VALUES(randomblob(100));
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
    INSERT INTO t3 SELECT randomblob(100) FROM t3;
  }

  db_save_and_close
} {}

foreach {tn sql} {
  1 { BEGIN;
        INSERT INTO t1 VALUES('123');
        INSERT INTO t2 VALUES('456');
      COMMIT;
  }
  2 { BEGIN;
        INSERT INTO t1 VALUES('123');
      COMMIT;
  }
} {
  db_restore
  sqlite3 db test.db -vfs devsym
  execsql {
    PRAGMA mmap_size = 0;
    SELECT x FROM t3 ORDER BY rowid;
    SELECT x FROM t3 ORDER BY x;
  }
  do_execsql_test 6.2.$tn.1 { PRAGMA integrity_check } {ok}
  do_execsql_test 6.2.$tn.2 $sql

  # Corrupt the database file on disk. This should not matter for the
  # purposes of the following "PRAGMA integrity_check", as the entire
  # database should be cached in the pager-cache. If corruption is
  # reported, it indicates that executing $sql caused the pager cache
  # to be flushed. Which is a bug.
  hexio_write test.db [expr 1024 * 5] [string repeat 00 2048]
  do_execsql_test 6.2.$tn.3 { PRAGMA integrity_check } {ok}
  db close
}

sqlite3_simulate_device -char {} -sectorsize 0
finish_test

    DELETE FROM t5 WHERE x>0;
    SELECT * FROM t5;
  }
} {}

ifcapable subquery&&vtab {
  do_test memdb-7.1 {
    load_static_extension db wholenumber
    execsql {
      CREATE TABLE t6(x);
      CREATE VIRTUAL TABLE nums USING wholenumber;
      INSERT INTO t6 SELECT value FROM nums WHERE value BETWEEN 1 AND 256;
      SELECT count(*) FROM (SELECT DISTINCT x FROM t6);
    }
  } {256}

      set str [format %.8x [expr [set ::rcnt] ^ 0xbdf20da3]] 
      string range [string repeat [set str] [expr [set n]/4]] 1 [set n]
    }
    $dbname func rblob rblob
  }]
}

# For cases 1.1 and 1.4, the number of pages read using xRead() is 4 on
# unix and 9 on windows. The difference is that windows only ever maps
# an integer number of OS pages (i.e. creates mappings that are a multiple 
# of 4KB in size). Whereas on unix any sized mapping may be created.
#
foreach {t mmap_size nRead c2init} {
  1.1 { PRAGMA mmap_size = 67108864 } /[49]/ {PRAGMA mmap_size = 0}
  1.2 { PRAGMA mmap_size =    53248 } 150    {PRAGMA mmap_size = 0}
  1.3 { PRAGMA mmap_size =        0 } 344    {PRAGMA mmap_size = 0}
  1.4 { PRAGMA mmap_size = 67108864 } /[49]/ {PRAGMA mmap_size = 67108864 }
  1.5 { PRAGMA mmap_size =    53248 } 150    {PRAGMA mmap_size = 67108864 }
  1.6 { PRAGMA mmap_size =        0 } 344    {PRAGMA mmap_size = 67108864 }
} {

  do_multiclient_test tn {
    sql1 {PRAGMA page_size=1024}
    sql1 $mmap_size
    sql2 $c2init

    code2 [register_rblob_code db2 0]

  All FTS3 tests except fts3rnd.test.
} -files {
  fts3aa.test fts3ab.test fts3ac.test fts3ad.test fts3ae.test
  fts3af.test fts3ag.test fts3ah.test fts3ai.test fts3aj.test
  fts3ak.test fts3al.test fts3am.test fts3an.test fts3ao.test
  fts3atoken.test fts3b.test fts3c.test fts3cov.test fts3d.test
  fts3defer.test fts3defer2.test fts3e.test fts3expr.test fts3expr2.test 
  fts3expr3.test
  fts3near.test fts3query.test fts3shared.test fts3snippet.test 
  fts3sort.test
  fts3fault.test fts3malloc.test fts3matchinfo.test
  fts3aux1.test fts3comp1.test fts3auto.test
  fts4aa.test fts4content.test
  fts3conf.test fts3prefix.test fts3fault2.test fts3corrupt.test
  fts3corrupt2.test fts3first.test fts4langid.test fts4merge.test

      }
      return "disk"
    }
  }
  return "unknown"
}

# Application_ID
#
do_test pragma-8.3.1 {
  execsql {
    PRAGMA application_id;
  }
} {0}
do_test pragma-8.3.2 {
  execsql {PRAGMA Application_ID(12345); PRAGMA application_id;}
} {12345}

# Test temp_store and temp_store_directory pragmas
#
ifcapable pager_pragmas {
do_test pragma-9.1 {
  db close
  sqlite3 db test.db

# This file implements test for the REGEXP operator in test_regexp.c.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test regexp1-1.1 {
  load_static_extension db regexp
  db eval {
    CREATE TABLE t1(x INTEGER PRIMARY KEY, y TEXT);
    INSERT INTO t1 VALUES(1, 'For since by man came death,');
    INSERT INTO t1 VALUES(2, 'by man came also the resurrection of the dead.');
    INSERT INTO t1 VALUES(3, 'For as in Adam all die,');
    INSERT INTO t1 VALUES(4, 'even so in Christ shall all be made alive.');

    db eval {
      SELECT t1.*, t2.*, t3.*, t4.b
        FROM (t1 LEFT JOIN t2 USING(a)) JOIN (t3 LEFT JOIN t4 USING(a))
             ON t1.a=t3.a-111;
    }
  } {111 x1 111 x2 222 x3 {}}
}

# The following test was added on 2013-04-24 in order to verify that
# the datatypes and affinities of sub-sub-queries are set prior to computing
# the datatypes and affinities of the parent sub-queries because the 
# latter computation depends on the former.
#
do_execsql_test selectD-4.1 {
  CREATE TABLE t41(a INTEGER PRIMARY KEY, b INTEGER);
  CREATE TABLE t42(d INTEGER PRIMARY KEY, e INTEGER);
  CREATE TABLE t43(f INTEGER PRIMARY KEY, g INTEGER);
  EXPLAIN QUERY PLAN
  SELECT * 
   FROM t41
   LEFT JOIN (SELECT count(*) AS cnt, x1.d
                FROM (t42 INNER JOIN t43 ON d=g) AS x1
               WHERE x1.d>5
               GROUP BY x1.d) AS x2
                  ON t41.b=x2.d;
} {/.*SEARCH SUBQUERY 1 AS x2 USING AUTOMATIC.*/}

finish_test

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix spellfix

ifcapable !vtab { finish_test ; return }

load_static_extension db spellfix nextchar

set vocab {
rabbi rabbit rabbits rabble rabid rabies raccoon raccoons race raced racer
racers races racetrack racial racially racing rack racked racket racketeer
racketeering racketeers rackets racking racks radar radars radial radially
radian radiance radiant radiantly radiate radiated radiates radiating radiation
radiations radiator radiators radical radically radicals radices radii radio

} {
  do_execsql_test 1.2.$tn {
    SELECT word, matchlen FROM t1 WHERE word MATCH $word 
     ORDER BY score, word LIMIT 5
  } $res
}

# Tests of the next_char function.
#
do_test 1.10 {
  db eval {
    CREATE TABLE vocab(w TEXT PRIMARY KEY);
    INSERT INTO vocab SELECT word FROM t1;
  }
} {}
do_execsql_test 1.11 {
  SELECT next_char('re','vocab','w');
} {a}
do_execsql_test 1.12 {
  SELECT next_char('r','vocab','w');
} {ae}
do_execsql_test 1.13 {
  SELECT next_char('','vocab','w');
} {r}
do_test 1.14 {
  catchsql {SELECT next_char('','xyzzy','a')}
} {1 {no such table: xyzzy}}

do_execsql_test 2.1 {
  CREATE VIRTUAL TABLE t2 USING spellfix1;
  INSERT INTO t2 (word, soundslike) VALUES('school', 'skuul');
  INSERT INTO t2 (word, soundslike) VALUES('psalm', 'sarm');
  SELECT word, matchlen FROM t2 WHERE word MATCH 'sar*' LIMIT 5;
} {psalm 4}

    }
  } {wal A 3 4 B 1 2 C 1 2}
}

db close
forcedelete test.db test.db-wal
sqlite3 db test.db
load_static_extension db wholenumber
db eval {
  PRAGMA journal_mode=WAL;
  CREATE TABLE t1(a,b);
  CREATE INDEX t1b ON t1(b);
  CREATE TABLE t2(x,y);
  CREATE VIRTUAL TABLE nums USING wholenumber;
  INSERT INTO t2 SELECT value, randomblob(1000) FROM nums

} {I I I I I I I I I I II II II II II II II II II II III III III III III 9 1}


do_test where8-3.21 {
  execsql_status {
    SELECT a, d FROM t1, (t2) WHERE (a=d OR b=e) AND a<5 ORDER BY a
  }
} {1 1 2 2 3 3 4 2 4 4 0 0}
do_test where8-3.21.1 {
  execsql_status {
    SELECT a, d FROM t1, ((t2)) AS t3 WHERE (a=d OR b=e) AND a<5 ORDER BY a
  }
} {1 1 2 2 3 3 4 2 4 4 0 0}
do_test where8-3.21.2 {
  execsql_status {
    SELECT a, d FROM t1, ((SELECT * FROM t2)) AS t3 WHERE (a=d OR b=e) AND a<5 ORDER BY a
  }
} {1 1 2 2 3 3 4 2 4 4 0 0}
do_test where8-3.22 {
  execsql_status {
    SELECT a, d FROM ((((((t1))), (((t2))))))
     WHERE (a=d OR b=e) AND a<5 ORDER BY a
  }
} {1 1 2 2 3 3 4 2 4 4 0 0}
do_test where8-3.23 {
  execsql_status {
    SELECT * FROM ((SELECT * FROM t2)) AS t3;
  }
} {1 {} I 2 four IV 3 {} IX 4 sixteen XVI 5 {} XXV 6 thirtysix XXXVI 7 fortynine XLIX 8 sixtyeight LXIV 9 eightyone LXXXIX 10 {} C 9 0}

#-----------------------------------------------------------------------
# The following tests - where8-4.* - verify that adding or removing 
# indexes does not change the results returned by various queries.
#
do_test where8-4.1 {
  execsql {

  set ::max_journal_size 0
  proc xDeleteCallback {method file args} {
    set sz [file size $file]
    if {$sz>$::max_journal_size} {set ::max_journal_size $sz}
  }
  tv filter xDelete
  tv script xDeleteCallback
  load_static_extension db wholenumber
  db eval {
    PRAGMA page_size=1024;
    PRAGMA journal_mode=DELETE;
    PRAGMA cache_size=5;
    CREATE VIRTUAL TABLE nums USING wholenumber;
    CREATE TABLE t1(x, y);
    INSERT INTO t1 SELECT value, randomblob(100) FROM nums

make sqlite3.c
gcc -o sqlite3 -g -Os -I. \
   -DSQLITE_THREADSAFE=0 \
   -DSQLITE_ENABLE_VFSTRACE \
   -DSQLITE_ENABLE_STAT3 \
   -DSQLITE_ENABLE_FTS4 \
   -DSQLITE_ENABLE_RTREE \


   -DHAVE_READLINE \
   -DHAVE_USLEEP=1 \
   ../sqlite/src/shell.c \


   ../sqlite/src/test_vfstrace.c \
   sqlite3.c -ldl -lreadline -lncurses

  print_decode_line(aData, 40, 4, "Schema cookie");
  print_decode_line(aData, 44, 4, "Schema format version");
  print_decode_line(aData, 48, 4, "Default page cache size");
  print_decode_line(aData, 52, 4, "Largest auto-vac root page");
  print_decode_line(aData, 56, 4, "Text encoding");
  print_decode_line(aData, 60, 4, "User version");
  print_decode_line(aData, 64, 4, "Incremental-vacuum mode");
  print_decode_line(aData, 68, 4, "Application ID");
  print_decode_line(aData, 72, 4, "meta[8]");
  print_decode_line(aData, 76, 4, "meta[9]");
  print_decode_line(aData, 80, 4, "meta[10]");
  print_decode_line(aData, 84, 4, "meta[11]");
  print_decode_line(aData, 88, 4, "meta[12]");
  print_decode_line(aData, 92, 4, "Change counter for version number");
  print_decode_line(aData, 96, 4, "SQLite version number");