SQLite

**
**   * An implementation of the SQL regexp() function (and hence REGEXP
**     operator) using the ICU uregex_XX() APIs.
**
**   * Implementations of the SQL scalar upper() and lower() functions
**     for case mapping.
**
**   * Integration of ICU and SQLite collation seqences.
**
**   * An implementation of the LIKE operator that uses ICU to 
**     provide case-independent matching.
*/

#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)

**    CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample);
**    CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample);
**
** Additional tables might be added in future releases of SQLite.
** The sqlite_stat2 table is not created or used unless the SQLite version
** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled
** with SQLITE_ENABLE_STAT2.  The sqlite_stat2 table is deprecated.
** The sqlite_stat2 table is superceded by sqlite_stat3, which is only
** created and used by SQLite versions 3.7.9 and later and with
** SQLITE_ENABLE_STAT3 defined.  The fucntionality of sqlite_stat3
** is a superset of sqlite_stat2.  
**
** Format of sqlite_stat1:
**
** There is normally one row per index, with the index identified by the

    /* Always defragment highly fragmented pages */
    rc = defragmentPage(pPage);
    if( rc ) return rc;
    top = get2byteNotZero(&data[hdr+5]);
  }else if( gap+2<=top ){
    /* Search the freelist looking for a free slot big enough to satisfy 
    ** the request. The allocation is made from the first free slot in 
    ** the list that is large enough to accomadate it.
    */
    int pc, addr;
    for(addr=hdr+1; (pc = get2byte(&data[addr]))>0; addr=pc){
      int size;            /* Size of the free slot */
      if( pc>usableSize-4 || pc<addr+4 ){
        return SQLITE_CORRUPT_BKPT;
      }

  }
  sqlite3BtreeLeave(p);
  return rc;
}

/*
** This routine is called prior to sqlite3PagerCommit when a transaction
** is commited for an auto-vacuum database.
**
** If SQLITE_OK is returned, then *pnTrunc is set to the number of pages
** the database file should be truncated to during the commit process. 
** i.e. the database has been reorganized so that only the first *pnTrunc
** pages are in use.
*/
static int autoVacuumCommit(BtShared *pBt){

** to iterate over the RHS of the IN operator in order to quickly locate
** all corresponding LHS elements.  All this routine does is initialize
** the register given by rMayHaveNull to NULL.  Calling routines will take
** care of changing this register value to non-NULL if the RHS is NULL-free.
**
** If rMayHaveNull is zero, that means that the subquery is being used
** for membership testing only.  There is no need to initialize any
** registers to indicate the presense or absence of NULLs on the RHS.
**
** For a SELECT or EXISTS operator, return the register that holds the
** result.  For IN operators or if an error occurs, the return value is 0.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3CodeSubselect(
  Parse *pParse,          /* Parsing context */

** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
** p1 is 1-indexed.  So substr(x,1,1) returns the first character
** of x.  If x is text, then we actually count UTF-8 characters.
** If x is a blob, then we count bytes.
**
** If p1 is negative, then we begin abs(p1) from the end of x[].
**
** If p2 is negative, return the p2 characters preceeding p1.
*/
static void substrFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const unsigned char *z;

** digits. */
static const char hexdigits[] = {
  '0', '1', '2', '3', '4', '5', '6', '7',
  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' 
};

/*
** EXPERIMENTAL - This is not an official function.  The interface may
** change.  This function may disappear.  Do not write code that depends
** on this function.
**
** Implementation of the QUOTE() function.  This function takes a single
** argument.  If the argument is numeric, the return value is the same as
** the argument.  If the argument is NULL, the return value is the string
** "NULL".  Otherwise, the argument is enclosed in single quotes with
** single-quote escapes.
*/
static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

    sqlite3_result_zeroblob(context, (int)n); /* IMP: R-00293-64994 */
  }
}

/*
** The replace() function.  Three arguments are all strings: call
** them A, B, and C. The result is also a string which is derived
** from A by replacing every occurance of B with C.  The match
** must be exact.  Collating sequences are not used.
*/
static void replaceFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){

  }
  return rc;
}

/*
** Another built-in collating sequence: NOCASE. 
**
** This collating sequence is intended to be used for "case independant
** comparison". SQLite's knowledge of upper and lower case equivalents
** extends only to the 26 characters used in the English language.
**
** At the moment there is only a UTF-8 implementation.
*/
static int nocaseCollatingFunc(
  void *NotUsed,

#endif

/*
** Test to see whether or not the database connection is in autocommit
** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
** by default.  Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
int sqlite3_get_autocommit(sqlite3 *db){
  return db->autoCommit;
}

/*
** The following routines are subtitutes for constants SQLITE_CORRUPT,

** If the database image is smaller than the requested page or if a 
** non-zero value is passed as the noContent parameter and the 
** requested page is not already stored in the cache, then no 
** actual disk read occurs. In this case the memory image of the 
** page is initialized to all zeros. 
**
** If noContent is true, it means that we do not care about the contents
** of the page. This occurs in two seperate scenarios:
**
**   a) When reading a free-list leaf page from the database, and
**
**   b) When a savepoint is being rolled back and we need to load
**      a new page into the cache to be filled with the data read
**      from the savepoint journal.
**

%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.

// Define operator precedence early so that this is the first occurance
// of the operator tokens in the grammer.  Keeping the operators together
// causes them to be assigned integer values that are close together,
// which keeps parser tables smaller.
//
// The token values assigned to these symbols is determined by the order
// in which lemon first sees them.  It must be the case that ISNULL/NOTNULL,
// NE/EQ, GT/LE, and GE/LT are separated by only a single value.  See

*/
static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){
  PCache1 *pCache;      /* The newly created page cache */
  PGroup *pGroup;       /* The group the new page cache will belong to */
  int sz;               /* Bytes of memory required to allocate the new cache */

  /*
  ** The seperateCache variable is true if each PCache has its own private
  ** PGroup.  In other words, separateCache is true for mode (1) where no
  ** mutexing is required.
  **
  **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT
  **
  **   *  Always use a unified cache in single-threaded applications
  **

  }else

#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
#endif

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  /* Pragma "quick_check" is an experimental reduced version of 
  ** integrity_check designed to detect most database corruption
  ** without most of the overhead of a full integrity-check.
  */
  if( sqlite3StrICmp(zLeft, "integrity_check")==0
   || sqlite3StrICmp(zLeft, "quick_check")==0 
  ){
    int i, j, addr, mxErr;

          prefix = '-';
        }else{
          if( flag_plussign )          prefix = '+';
          else if( flag_blanksign )    prefix = ' ';
          else                         prefix = 0;
        }
        if( xtype==etGENERIC && precision>0 ) precision--;
#if 0
        /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
        for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
#else
        /* It makes more sense to use 0.5 */
        for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
#endif
        if( xtype==etFLOAT ) realvalue += rounder;
        /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
        exp = 0;
        if( sqlite3IsNaN((double)realvalue) ){
          bufpt = "NaN";
          length = 3;
          break;

  if( p ){
    clearSelect(db, p);
    sqlite3DbFree(db, p);
  }
}

/*
** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
** type of join.  Return an integer constant that expresses that type
** in terms of the following bit values:
**
**     JT_INNER
**     JT_CROSS
**     JT_OUTER
**     JT_NATURAL

  int iLimit = 0;
  int iOffset;
  int addr1, n;
  if( p->iLimit ) return;

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** contraversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
  */
  sqlite3ExprCacheClear(pParse);
  assert( p->pOffset==0 || p->pLimit!=0 );
  if( p->pLimit ){
    p->iLimit = iLimit = ++pParse->nMem;

      if( pItem->viaCoroutine==0 ){
        sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
      }
      continue;
    }

    /* Increment Parse.nHeight by the height of the largest expression
    ** tree refered to by this, the parent select. The child select
    ** may contain expression trees of at most
    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
    ** more conservative than necessary, but much easier than enforcing
    ** an exact limit.
    */
    pParse->nHeight += sqlite3SelectExprHeight(p);

# define SQLITE_PTR_TO_INT(X)  ((int)(X))
#endif

/*
** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
** 0 means mutexes are permanently disable and the library is never
** threadsafe.  1 means the library is serialized which is the highest
** level of threadsafety.  2 means the libary is multithreaded - multiple
** threads can use SQLite as long as no two threads try to use the same
** database connection at the same time.
**
** Older versions of SQLite used an optional THREADSAFE macro.
** We support that for legacy.
*/
#if !defined(SQLITE_THREADSAFE)

*/
static char *sqlite_static_bind_value = 0;
static int sqlite_static_bind_nbyte = 0;

/*
** Usage:  sqlite3_bind  VM  IDX  VALUE  FLAGS
**
** Sets the value of the IDX-th occurance of "?" in the original SQL
** string.  VALUE is the new value.  If FLAGS=="null" then VALUE is
** ignored and the value is set to NULL.  If FLAGS=="static" then
** the value is set to the value of a static variable named
** "sqlite_static_bind_value".  If FLAGS=="normal" then a copy
** of the VALUE is made.  If FLAGS=="blob10" then a VALUE is ignored
** an a 10-byte blob "abc\000xyz\000pq" is inserted.
*/

**
** If wal_checkpoint_v2() returns any value other than SQLITE_BUSY or
** SQLITE_OK, then this command returns TCL_ERROR. The Tcl result is set
** to the error message obtained from sqlite3_errmsg().
**
** Otherwise, this command returns a list of three integers. The first integer
** is 1 if SQLITE_BUSY was returned, or 0 otherwise. The following two integers
** are the values returned via the output paramaters by wal_checkpoint_v2() -
** the number of frames in the log and the number of frames in the log
** that have been checkpointed.
*/
static int test_wal_checkpoint_v2(
  ClientData clientData, /* Unused */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */

    sqlite3VdbeChangeP5(v, (u8)bRecursive);
  }
}

/*
** This is called to code the required FOR EACH ROW triggers for an operation
** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)
** is given by the op paramater. The tr_tm parameter determines whether the
** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then
** parameter pChanges is passed the list of columns being modified.
**
** If there are no triggers that fire at the specified time for the specified
** operation on pTab, this function is a no-op.
**
** The reg argument is the address of the first in an array of registers 

** attached databases.
**
** If P2 is non-zero, then a write-transaction is started.  A RESERVED lock is
** obtained on the database file when a write-transaction is started.  No
** other process can start another write transaction while this transaction is
** underway.  Starting a write transaction also creates a rollback journal. A
** write transaction must be started before any changes can be made to the
** database.  If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
** on the file.
**
** If a write-transaction is started and the Vdbe.usesStmtJournal flag is
** true (this flag is set if the Vdbe may modify more than one row and may
** throw an ABORT exception), a statement transaction may also be opened.
** More specifically, a statement transaction is opened iff the database
** connection is currently not in autocommit mode, or if there are other
** active statements. A statement transaction allows the changes made by this

#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
  int iType = sqlite3_value_type( columnMem(pStmt,i) );
  columnMallocFailure(pStmt);
  return iType;
}

/* The following function is experimental and subject to change or
** removal */
/*int sqlite3_column_numeric_type(sqlite3_stmt *pStmt, int i){
**  return sqlite3_value_numeric_type( columnMem(pStmt,i) );
**}
*/

/*
** Convert the N-th element of pStmt->pColName[] into a string using
** xFunc() then return that string.  If N is out of range, return 0.
**
** There are up to 5 names for each column.  useType determines which
** name is returned.  Here are the names:
**

#endif

/*
** If the Vdbe passed as the first argument opened a statement-transaction,
** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 
** statement transaction is commtted.
**
** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 
** Otherwise SQLITE_OK.
*/
int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
  sqlite3 *const db = p->db;
  int rc = SQLITE_OK;

** comparing aIter[2*i-N] and aIter[2*i-N+1]. Whichever key is smaller, the
** aTree element is set to the index of it. 
**
** For the purposes of this comparison, EOF is considered greater than any
** other key value. If the keys are equal (only possible with two EOF
** values), it doesn't matter which index is stored.
**
** The (N/4) elements of aTree[] that preceed the final (N/2) described 
** above contains the index of the smallest of each block of 4 iterators.
** And so on. So that aTree[1] contains the index of the iterator that 
** currently points to the smallest key value. aTree[0] is unused.
**
** Example:
**
**     aIter[0] -> Banana