SQLite

**
*************************************************************************
** This file contains code used to implement the sqlite3_set_authorizer()
** API.  This facility is an optional feature of the library.  Embedded
** systems that do not need this facility may omit it by recompiling
** the library with -DSQLITE_OMIT_AUTHORIZATION=1
**
** $Id: auth.c,v 1.24 2006/01/13 13:55:45 drh Exp $
*/
#include "sqliteInt.h"

/*
** All of the code in this file may be omitted by defining a single
** macro.
*/

  TriggerStack *pStack; /* The stack of current triggers */
  int iDb;              /* The index of the database the expression refers to */

  if( db->xAuth==0 ) return;
  if( pExpr->op==TK_AS ) return;
  assert( pExpr->op==TK_COLUMN );
  iDb = sqlite3SchemaToIndex(pParse->db, pExpr->pSchema);
  if( iDb<0 ){
    /* An attempt to read a column out of a subquery or other
    ** temporary table. */
    return;
  }
  for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){
    if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
  }
  if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){
    pTab = pTabList->a[iSrc].pTab;
  }else if( (pStack = pParse->trigStack)!=0 ){
    /* This must be an attempt to read the NEW or OLD pseudo-tables

    zCol = pTab->aCol[pExpr->iColumn].zName;
  }else if( pTab->iPKey>=0 ){
    assert( pTab->iPKey<pTab->nCol );
    zCol = pTab->aCol[pTab->iPKey].zName;
  }else{
    zCol = "ROWID";
  }
  assert( iDb>=0 && iDb<db->nDb );
  zDBase = db->aDb[iDb].zName;
  rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 
                 pParse->zAuthContext);
  if( rc==SQLITE_IGNORE ){
    pExpr->op = TK_NULL;
  }else if( rc==SQLITE_DENY ){
    if( db->nDb>2 || iDb!=0 ){

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.297 2006/01/13 11:22:07 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

**   because the table is empty or because BtreeCursorFirst() has not been
**   called.
**
** CURSOR_REQUIRESEEK:
**   The table that this cursor was opened on still exists, but has been 
**   modified since the cursor was last used. The cursor position is saved
**   in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in 
**   this state, restoreOrClearCursorPosition() can be called to attempt to seek 
**   the cursor to the saved position.
*/
#define CURSOR_INVALID           0
#define CURSOR_VALID             1
#define CURSOR_REQUIRESEEK       2

/*

  ** shared-cache feature disabled, then there is only ever one user
  ** of each BtShared structure and so this locking is not necessary. 
  ** So define the lock related functions as no-ops.
  */
  #define queryTableLock(a,b,c) SQLITE_OK
  #define lockTable(a,b,c) SQLITE_OK
  #define unlockAllTables(a)
  #define restoreOrClearCursorPosition(a,b) SQLITE_OK
  #define saveAllCursors(a,b,c) SQLITE_OK

#else

/*
** Save the current cursor position in the variables BtCursor.nKey 
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.

  return SQLITE_OK;
}

/*
** Restore the cursor to the position it was in (or as close to as possible)
** when saveCursorPosition() was called. Note that this call deletes the 
** saved position info stored by saveCursorPosition(), so there can be
** at most one effective restoreOrClearCursorPosition() call after each 
** saveCursorPosition().
**
** If the second argument argument - doSeek - is false, then instead of 
** returning the cursor to it's saved position, any saved position is deleted
** and the cursor state set to CURSOR_INVALID.
*/
static int restoreOrClearCursorPositionX(BtCursor *pCur, int doSeek){
  int rc = SQLITE_OK;

  assert( sqlite3ThreadDataReadOnly()->useSharedData );
  assert( pCur->eState==CURSOR_REQUIRESEEK );
  if( doSeek ){
    rc = sqlite3BtreeMoveto(pCur, pCur->pKey, pCur->nKey, &pCur->skip);
  }else{
    pCur->eState = CURSOR_INVALID;
  }
  if( rc==SQLITE_OK ){
    sqliteFree(pCur->pKey);
    pCur->pKey = 0;
    assert( CURSOR_VALID==pCur->eState || CURSOR_INVALID==pCur->eState );

  }
  return rc;
}

#define restoreOrClearCursorPosition(p,x) \
  (p->eState==CURSOR_REQUIRESEEK?restoreOrClearCursorPositionX(p,x):SQLITE_OK)

/*
** Query to see if btree handle p may obtain a lock of type eLock 
** (READ_LOCK or WRITE_LOCK) on the table with root-page iTab. Return
** SQLITE_OK if the lock may be obtained (by calling lockTable()), or
** SQLITE_LOCKED if not.
*/
static int queryTableLock(Btree *p, Pgno iTab, u8 eLock){

  }
  pCur = sqliteMalloc( sizeof(*pCur) );
  if( pCur==0 ){
    rc = SQLITE_NOMEM;
    goto create_cursor_exception;
  }
  pCur->pgnoRoot = (Pgno)iTable;

  if( iTable==1 && sqlite3pager_pagecount(pBt->pPager)==0 ){
    rc = SQLITE_EMPTY;
    goto create_cursor_exception;
  }
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
  if( rc!=SQLITE_OK ){
    goto create_cursor_exception;
  }

  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables, link the cursor into the BtShared list and set *ppCur (the
  ** output argument to this function).
  */
  pCur->xCompare = xCmp ? xCmp : dfltCompare;
  pCur->pArg = pArg;
  pCur->pBtree = p;
  pCur->wrFlag = wrFlag;


  pCur->pNext = pBt->pCursor;
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur;
  }

  pBt->pCursor = pCur;
  pCur->eState = CURSOR_INVALID;
  *ppCur = pCur;

  return SQLITE_OK;
create_cursor_exception:
  if( pCur ){

/*
** Close a cursor.  The read lock on the database file is released
** when the last cursor is closed.
*/
int sqlite3BtreeCloseCursor(BtCursor *pCur){
  BtShared *pBt = pCur->pBtree->pBt;
  restoreOrClearCursorPosition(pCur, 0);
  if( pCur->pPrev ){
    pCur->pPrev->pNext = pCur->pNext;
  }else{
    pBt->pCursor = pCur->pNext;
  }
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur->pPrev;

** the key for the current entry.  If the cursor is not pointing
** to a valid entry, *pSize is set to 0. 
**
** For a table with the INTKEY flag set, this routine returns the key
** itself, not the number of bytes in the key.
*/
int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
  int rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
    if( pCur->eState==CURSOR_INVALID ){
      *pSize = 0;
    }else{
      getCellInfo(pCur);
      *pSize = pCur->info.nKey;
    }
  }
  return rc;
}

/*
** Set *pSize to the number of bytes of data in the entry the
** cursor currently points to.  Always return SQLITE_OK.
** Failure is not possible.  If the cursor is not currently
** pointing to an entry (which can happen, for example, if
** the database is empty) then *pSize is set to 0.
*/
int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
  int rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
    if( pCur->eState==CURSOR_INVALID ){
      /* Not pointing at a valid entry - set *pSize to 0. */
      *pSize = 0;
    }else{
      getCellInfo(pCur);

  assert( pCur!=0 && pCur->pPage!=0 );
  assert( pCur->eState==CURSOR_VALID );
  pBt = pCur->pBtree->pBt;
  pPage = pCur->pPage;
  pageIntegrity(pPage);
  assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
  getCellInfo(pCur);
  aPayload = pCur->info.pCell + pCur->info.nHeader;

  if( pPage->intKey ){
    nKey = 0;
  }else{
    nKey = pCur->info.nKey;
  }
  assert( offset>=0 );
  if( skipKey ){

** begins at "offset".
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong.  An error is returned if "offset+amt" is larger than
** the available payload.
*/
int sqlite3BtreeKey(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
  int rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_VALID );
    assert( pCur->pPage!=0 );
    if( pCur->pPage->intKey ){
      return SQLITE_CORRUPT_BKPT;
    }
    assert( pCur->pPage->intKey==0 );

** begins at "offset".
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong.  An error is returned if "offset+amt" is larger than
** the available payload.
*/
int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
  int rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc==SQLITE_OK ){
    assert( pCur->eState==CURSOR_VALID );
    assert( pCur->pPage!=0 );
    assert( pCur->idx>=0 && pCur->idx<pCur->pPage->nCell );
    rc = getPayload(pCur, offset, amt, pBuf, 1);
  }
  return rc;

}

/*
** Move the cursor to the root page
*/
static int moveToRoot(BtCursor *pCur){
  MemPage *pRoot;
  int rc = SQLITE_OK;
  BtShared *pBt = pCur->pBtree->pBt;

  restoreOrClearCursorPosition(pCur, 0);
  assert( pCur->pPage );
  pRoot = pCur->pPage;
  if( pRoot->pgno==pCur->pgnoRoot ){
    assert( pRoot->isInit );
  }else{
    if( 

      SQLITE_OK!=(rc = getAndInitPage(pBt, pCur->pgnoRoot, &pRoot, 0))
    ){
      pCur->eState = CURSOR_INVALID;
      return rc;
    }
    releasePage(pCur->pPage);
    pageIntegrity(pRoot);
    pCur->pPage = pRoot;
  }
  pCur->idx = 0;
  pCur->info.nSize = 0;
  if( pRoot->nCell==0 && !pRoot->leaf ){
    Pgno subpage;
    assert( pRoot->pgno==1 );
    subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
    assert( subpage>0 );
    pCur->eState = CURSOR_VALID;
    rc = moveToChild(pCur, subpage);
  }
  pCur->eState = ((pCur->pPage->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
  return rc;
}

/*
** Move the cursor down to the left-most leaf entry beneath the
** entry to which it is currently pointing.
**
** The left-most leaf is the one with the smallest key - the first
** in ascending order.
*/
static int moveToLeftmost(BtCursor *pCur){
  Pgno pgno;
  int rc;
  MemPage *pPage;

  assert( pCur->eState==CURSOR_VALID );

/*
** Move the cursor down to the right-most leaf entry beneath the
** page to which it is currently pointing.  Notice the difference
** between moveToLeftmost() and moveToRightmost().  moveToLeftmost()
** finds the left-most entry beneath the *entry* whereas moveToRightmost()
** finds the right-most entry beneath the *page*.
**
** The right-most entry is the one with the largest key - the last
** key in ascending order.
*/
static int moveToRightmost(BtCursor *pCur){
  Pgno pgno;
  int rc;
  MemPage *pPage;

  assert( pCur->eState==CURSOR_VALID );

**                  exactly matches pKey.
**
**     *pRes>0      The cursor is left pointing at an entry that
**                  is larger than pKey.
*/
int sqlite3BtreeMoveto(BtCursor *pCur, const void *pKey, i64 nKey, int *pRes){
  int rc;
  int tryRightmost;
  rc = moveToRoot(pCur);
  if( rc ) return rc;
  assert( pCur->pPage );
  assert( pCur->pPage->isInit );
  tryRightmost = pCur->pPage->intKey;
  if( pCur->eState==CURSOR_INVALID ){
    *pRes = -1;
    assert( pCur->pPage->nCell==0 );
    return SQLITE_OK;
  }
   for(;;){
    int lwr, upr;
    Pgno chldPg;
    MemPage *pPage = pCur->pPage;
    int c = -1;  /* pRes return if table is empty must be -1 */
    lwr = 0;
    upr = pPage->nCell-1;
    if( !pPage->intKey && pKey==0 ){
      return SQLITE_CORRUPT_BKPT;
    }
    pageIntegrity(pPage);
    while( lwr<=upr ){
      void *pCellKey;
      i64 nCellKey;
      pCur->idx = (lwr+upr)/2;
      pCur->info.nSize = 0;
      if( pPage->intKey ){
        u8 *pCell;
        if( tryRightmost ){
          pCur->idx = upr;
        }
        pCell = findCell(pPage, pCur->idx) + pPage->childPtrSize;
        if( pPage->hasData ){
          int dummy;
          pCell += getVarint32(pCell, &dummy);
        }
        getVarint(pCell, &nCellKey);

        if( nCellKey<nKey ){
          c = -1;
        }else if( nCellKey>nKey ){
          c = +1;
          tryRightmost = 0;
        }else{
          c = 0;
        }
      }else{
        int available;
        pCellKey = (void *)fetchPayload(pCur, &available, 0);
        nCellKey = pCur->info.nKey;

        if( available>=nCellKey ){
          c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);
        }else{
          pCellKey = sqliteMallocRaw( nCellKey );
          if( pCellKey==0 ) return SQLITE_NOMEM;
          rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey);
          c = pCur->xCompare(pCur->pArg, nCellKey, pCellKey, nKey, pKey);

** this routine was called, then set *pRes=1.
*/
int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
  int rc;
  MemPage *pPage = pCur->pPage;

#ifndef SQLITE_OMIT_SHARED_CACHE
  rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  if( pCur->skip>0 ){
    pCur->skip = 0;
    *pRes = 0;
    return SQLITE_OK;

*/
int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
  int rc;
  Pgno pgno;
  MemPage *pPage;

#ifndef SQLITE_OMIT_SHARED_CACHE
  rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  if( pCur->skip<0 ){
    pCur->skip = 0;
    *pRes = 0;
    return SQLITE_OK;

    return SQLITE_PERM;   /* Cursor not open for writing */
  }
  if( checkReadLocks(pBt, pCur->pgnoRoot, pCur) ){
    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
  }

  /* Save the positions of any other cursors open on this table */
  restoreOrClearCursorPosition(pCur, 0);
  if( 

    SQLITE_OK!=(rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur)) ||
    SQLITE_OK!=(rc = sqlite3BtreeMoveto(pCur, pKey, nKey, &loc))
  ){
    return rc;
  }

  pPage = pCur->pPage;

  /* Restore the current cursor position (a no-op if the cursor is not in 
  ** CURSOR_REQUIRESEEK state) and save the positions of any other cursors 
  ** open on the same table. Then call sqlite3pager_write() on the page
  ** that the entry will be deleted from.
  */
  if( 
    (rc = restoreOrClearCursorPosition(pCur, 1)) ||
    (rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur)) ||
    (rc = sqlite3pager_write(pPage->aData))
  ){
    return rc;
  }

  /* Locate the cell within it's page and leave pCell pointing to the

/*
** Return the flag byte at the beginning of the page that the cursor
** is currently pointing to.
*/
int sqlite3BtreeFlags(BtCursor *pCur){
  /* TODO: What about CURSOR_REQUIRESEEK state? Probably need to call
  ** restoreOrClearCursorPosition() here.
  */
  MemPage *pPage = pCur->pPage;
  return pPage ? pPage->aData[pPage->hdrOffset] : 0;
}

#ifdef SQLITE_DEBUG
/*

** This routine is used for testing and debugging only.
*/
int sqlite3BtreeCursorInfo(BtCursor *pCur, int *aResult, int upCnt){
  int cnt, idx;
  MemPage *pPage = pCur->pPage;
  BtCursor tmpCur;

  int rc = restoreOrClearCursorPosition(pCur, 1);
  if( rc!=SQLITE_OK ){
    return rc;
  }

  pageIntegrity(pPage);
  assert( pPage->isInit );
  getTempCursor(pCur, &tmpCur);

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.379 2006/01/13 06:33:24 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.

  int i;

  if( (p = pParse->pNewTable)==0 ) return;
  i = p->nCol-1;

  if( sqlite3LocateCollSeq(pParse, zType, nType) ){
    Index *pIdx;
    p->aCol[i].zColl = sqliteStrNDup(zType, nType);
  
    /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
    ** then an index may have been created on this column before the
    ** collation type was added. Correct this if it is the case.
    */
    for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->nColumn==1 );

  if( pName1==0 || pName1->z==0 ){
    reindexDatabases(pParse, 0);
    return;
  }else if( pName2==0 || pName2->z==0 ){
    assert( pName1->z );
    pColl = sqlite3FindCollSeq(db, ENC(db), (char*)pName1->z, pName1->n, 0);
    if( pColl ){
      char *z = sqliteStrNDup(pName1->z, pName1->n);
      if( z ){
        reindexDatabases(pParse, z);
        sqliteFree(z);
      }
      return;
    }
  }

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.50 2006/01/13 01:17:21 drh Exp $
**
** NOTES:
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system.

    if( val<min || val>max || (nextC!=0 && nextC!=*zDate) ){
      return cnt;
    }
    *pVal = val;
    zDate++;
    cnt++;
  }while( nextC );
  va_end(ap);
  return cnt;
}

/*
** Read text from z[] and convert into a floating point number.  Return
** the number of digits converted.
*/

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.249 2006/01/13 06:33:24 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

        break;
      }
    }
    if( i>=pParse->nVarExpr ){
      pExpr->iTable = ++pParse->nVar;
      if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
        pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
        sqliteReallocOrFree((void**)&pParse->apVarExpr,
                       pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) );
      }
      if( !sqlite3ThreadDataReadOnly()->mallocFailed ){
        assert( pParse->apVarExpr!=0 );
        pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
      }
    }

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.116 2006/01/12 22:17:50 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
/* #include <math.h> */
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

struct SumCtx {
  double sum;     /* Sum of terms */
  int cnt;        /* Number of elements summed */
  u8 seenFloat;   /* True if there has been any floating point value */
};

/*
** Routines used to compute the sum, average, and total.
**
** The SUM() function follows the (broken) SQL standard which means
** that it returns NULL if it sums over no inputs.  TOTAL returns
** 0.0 in that case.  In addition, TOTAL always returns a float where
** SUM might return an integer if it never encounters a floating point
** value.
*/
static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  SumCtx *p;
  int type;
  assert( argc==1 );
  p = sqlite3_aggregate_context(context, sizeof(*p));
  type = sqlite3_value_type(argv[0]);

static void avgFinalize(sqlite3_context *context){
  SumCtx *p;
  p = sqlite3_aggregate_context(context, 0);
  if( p && p->cnt>0 ){
    sqlite3_result_double(context, p->sum/(double)p->cnt);
  }
}
static void totalFinalize(sqlite3_context *context){
  SumCtx *p;
  p = sqlite3_aggregate_context(context, 0);
  sqlite3_result_double(context, p ? p->sum : 0.0);
}

/*
** An instance of the following structure holds the context of a
** variance or standard deviation computation.
*/
typedef struct StdDevCtx StdDevCtx;
struct StdDevCtx {

    u8 needCollSeq;
    void (*xStep)(sqlite3_context*,int,sqlite3_value**);
    void (*xFinalize)(sqlite3_context*);
  } aAggs[] = {
    { "min",    1, 0, 1, minmaxStep,   minMaxFinalize },
    { "max",    1, 2, 1, minmaxStep,   minMaxFinalize },
    { "sum",    1, 0, 0, sumStep,      sumFinalize    },
    { "total",  1, 0, 0, sumStep,      totalFinalize    },
    { "avg",    1, 0, 0, sumStep,      avgFinalize    },
    { "count",  0, 0, 0, countStep,    countFinalize  },
    { "count",  1, 0, 0, countStep,    countFinalize  },
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){

** sqlite3GenericRealloc
** sqlite3GenericOsFree
** sqlite3GenericAllocationSize
**
** Implementation of the os level dynamic memory allocation interface in terms
** of the standard malloc(), realloc() and free() found in many operating
** systems. No rocket science here.
**
** There are two versions of these four functions here. The version
** implemented here is only used if memory-management or memory-debugging is
** enabled. This version allocates an extra 8-bytes at the beginning of each
** block and stores the size of the allocation there.
**
** If neither memory-management or debugging is enabled, the second
** set of implementations is used instead.
*/
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || defined (SQLITE_MEMDEBUG)
void *sqlite3GenericMalloc(int n){
  char *p = (char *)malloc(n+8);
  assert(n>0);
  assert(sizeof(int)<=8);
  if( p ){
    *(int *)p = n;
  }

void sqlite3GenericFree(void *p){
  assert(p);
  free((void *)((char *)p - 8));
}
int sqlite3GenericAllocationSize(void *p){
  return p ? *(int *)((char *)p - 8) : 0;
}
#else
void *sqlite3GenericMalloc(int n){
  char *p = (char *)malloc(n);
  return (void *)p;
}
void *sqlite3GenericRealloc(void *p, int n){
  assert(n>0);
  p = realloc(p, n);
  return p;
}
void sqlite3GenericFree(void *p){
  assert(p);
  free(p);
}
#if 0   /* Never actually invoked */
int sqlite3GenericAllocationSize(void *p){
  assert(0);
}
#endif
#endif

  int nByte;
  nByte = strlen(zRelative) + MAX_PATH + 1001;
  zFull = sqliteMalloc( nByte );
  if( zFull==0 ) return 0;
  if( cygwin_conv_to_full_win32_path(zRelative, zFull) ) return 0;
#elif OS_WINCE
  /* WinCE has no concept of a relative pathname, or so I am told. */
  zFull = sqliteStrDup(zRelative);
#else
  char *zNotUsed;
  WCHAR *zWide;
  int nByte;
  zWide = utf8ToUnicode(zRelative);
  if( zWide ){
    WCHAR *zTemp, *zNotUsedW;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.22 2006/01/13 06:33:24 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates

/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements.  Return a success code.  If an
** error occurs, write an error message into *pzErrMsg.
**
** After a database is initialized, the DB_SchemaLoaded bit is set
** bit is set in the flags field of the Db structure. If the database
** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
  int i, rc;
  int called_initone = 0;
  
  if( db->init.busy ) return SQLITE_OK;
  rc = SQLITE_OK;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.294 2006/01/13 06:33:24 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.

    memset(&sNC, 0, sizeof(sNC));
    sNC.pSrcList = pSelect->pSrc;
    zType = sqliteStrDup(columnType(&sNC, p));
    pCol->zType = zType;
    pCol->affinity = sqlite3ExprAffinity(p);
    pColl = sqlite3ExprCollSeq(pParse, p);
    if( pColl ){
      pCol->zColl = sqliteStrDup(pColl->zName);
    }
  }
  pTab->iPKey = -1;
  return pTab;
}

/*

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.467 2006/01/13 06:33:24 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/

#define sqliteStrNDup(x,y)       sqlite3StrNDup(x,y)
#define sqliteReallocOrFree(x,y) sqlite3ReallocOrFree(x,y)

#endif

#define sqliteFree(x)          sqlite3FreeX(x)
#define sqliteAllocSize(x)     sqlite3AllocSize(x)


/*
** An instance of this structure might be allocated to store information
** specific to a single thread.
**
** To avoid a memory leak on windows, the content of this structure is
** checked at the conclusion of each API call.  If it is all zero, it

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used to translate between UTF-8, 
** UTF-16, UTF-16BE, and UTF-16LE.
**
** $Id: utf.c,v 1.36 2006/01/13 06:33:24 danielk1977 Exp $
**
** Notes on UTF-8:
**
**   Byte-0    Byte-1    Byte-2    Byte-3    Value
**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx

char *sqlite3utf16to8(const void *z, int nByte){
  Mem m;
  memset(&m, 0, sizeof(m));
  sqlite3VdbeMemSetStr(&m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
  assert( m.flags & MEM_Term );
  assert( m.flags & MEM_Str );
  return (m.flags & MEM_Dyn)!=0 ? m.z : sqliteStrDup(m.z);
}

/*
** pZ is a UTF-16 encoded unicode string. If nChar is less than zero,
** return the number of bytes up to (but not including), the first pair
** of consecutive 0x00 bytes in pZ. If nChar is not less than zero,
** then return the number of bytes in the first nChar unicode characters

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.170 2006/01/13 06:33:24 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*

** sqlite3Malloc(), sqlite3Realloc() or sqlite3ReallocOrFree().
**
** The number of bytes allocated does not include any overhead inserted by 
** any malloc() wrapper functions that may be called. So the value returned
** is the number of bytes that were available to SQLite using pointer p, 
** regardless of how much memory was actually allocated.
*/
#if 0          /* This is never actually used */
int sqlite3AllocSize(void *p){
  return OSSIZEOF(p);
}
#endif

/*
** Make a copy of a string in memory obtained from sqliteMalloc(). These 
** functions call sqlite3MallocRaw() directly instead of sqliteMalloc(). This
** is because when memory debugging is turned on, these two functions are 
** called via macros that record the current file and line number in the
** ThreadData structure.

**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
**
** $Id: vacuum.c,v 1.57 2006/01/13 01:48:59 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
#include "os.h"

#ifndef SQLITE_OMIT_VACUUM
/*

#ifndef SQLITE_OMIT_VACUUM
  const char *zFilename;  /* full pathname of the database file */
  int nFilename;          /* number of characters  in zFilename[] */
  char *zTemp = 0;        /* a temporary file in same directory as zFilename */
  Btree *pMain;           /* The database being vacuumed */
  Btree *pTemp;
  char *zSql = 0;

  int saved_flags;       /* Saved value of the db->flags */
  Db *pDb = 0;           /* Database to detach at end of vacuum */

  /* Save the current value of the write-schema flag before setting it. */
  saved_flags = db->flags;
  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.527 2006/01/13 06:33:24 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

** from sqliteMalloc().  This is different from Stringify() above in that
** Stringify() will use the NBFS bytes of static string space if the string
** will fit but this routine always mallocs for space.
** Return non-zero if we run out of memory.
*/
#define Dynamicify(P,enc) sqlite3VdbeMemDynamicify(P)

/*
** The header of a record consists of a sequence variable-length integers.
** These integers are almost always small and are encoded as a single byte.
** The following macro takes advantage this fact to provide a fast decode
** of the integers in a record header.  It is faster for the common case
** where the integer is a single byte.  It is a little slower when the
** integer is two or more bytes.  But overall it is faster.
**
** The following expressions are equivalent:
**
**     x = sqlite3GetVarint32( A, &B );
**
**     x = GetVarint( A, B );
**
*/
#define GetVarint(A,B)  ((B = *(A))<=0x7f ? 1 : sqlite3GetVarint32(A, &B))

/*
** An ephemeral string value (signified by the MEM_Ephem flag) contains
** a pointer to a dynamically allocated string where some other entity
** is responsible for deallocating that string.  Because the stack entry
** does not control the string, it might be deleted without the stack
** entry knowing it.

      if( avail>=payloadSize ){
        zRec = zData;
        pC->aRow = (u8*)zData;
      }else{
        pC->aRow = 0;
      }
    }
    idx = GetVarint((u8*)zData, szHdr);


    /* The KeyFetch() or DataFetch() above are fast and will get the entire
    ** record header in most cases.  But they will fail to get the complete
    ** record header if the record header does not fit on a single page
    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
    ** acquire the complete header text.

    ** of the record to the start of the data for the i-th column
    */
    offset = szHdr;
    assert( offset>0 );
    i = 0;
    while( idx<szHdr && i<nField && offset<=payloadSize ){
      aOffset[i] = offset;
      idx += GetVarint((u8*)&zData[idx], aType[i]);
      offset += sqlite3VdbeSerialTypeLen(aType[i]);
      i++;
    }
    Release(&sMem);
    sMem.flags = MEM_Null;

    /* If i is less that nField, then there are less fields in this

  int i = p->contextStackTop++;
  Context *pContext;

  assert( i>=0 );
  /* FIX ME: This should be allocated as part of the vdbe at compile-time */
  if( i>=p->contextStackDepth ){
    p->contextStackDepth = i+1;
    sqliteReallocOrFree((void**)&p->contextStack, sizeof(Context)*(i+1));
    if( p->contextStack==0 ) goto no_mem;
  }
  pContext = &p->contextStack[i];
  pContext->lastRowid = db->lastRowid;
  pContext->nChange = p->nChange;
  pContext->sFifo = p->sFifo;
  sqlite3VdbeFifoInit(&p->sFifo);

*/
int sqlite3VdbeMakeLabel(Vdbe *p){
  int i;
  i = p->nLabel++;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( i>=p->nLabelAlloc ){
    p->nLabelAlloc = p->nLabelAlloc*2 + 10;
    sqliteReallocOrFree((void**)&p->aLabel,
                          p->nLabelAlloc*sizeof(p->aLabel[0]));
  }
  if( p->aLabel ){
    p->aLabel[i] = -1;
  }
  return -1-i;
}

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.196 2006/01/13 13:01:19 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

/*
** Generate code that builds a probe for an index.  Details:
**
**    *  Check the top nColumn entries on the stack.  If any
**       of those entries are NULL, jump immediately to brk,
**       which is the loop exit, since no index entry will match
**       if any part of the key is NULL. Pop (nColumn+nExtra) 
**       elements from the stack.
**
**    *  Construct a probe entry from the top nColumn entries in
**       the stack with affinities appropriate for index pIdx. 
**       Only nColumn elements are popped from the stack in this case
**       (by OP_MakeRecord).
**
*/
static void buildIndexProbe(
  Vdbe *v, 
  int nColumn, 
  int nExtra, 
  int brk, 
  Index *pIdx
){
  sqlite3VdbeAddOp(v, OP_NotNull, -nColumn, sqlite3VdbeCurrentAddr(v)+3);
  sqlite3VdbeAddOp(v, OP_Pop, nColumn+nExtra, 0);
  sqlite3VdbeAddOp(v, OP_Goto, 0, brk);
  sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
  sqlite3IndexAffinityStr(v, pIdx);
}


/*

    Vdbe *v = pParse->pVdbe;

    sqlite3CodeSubselect(pParse, pX);
    iTab = pX->iTable;
    sqlite3VdbeAddOp(v, OP_Rewind, iTab, brk);
    VdbeComment((v, "# %.*s", pX->span.n, pX->span.z));
    pLevel->nIn++;
    sqliteReallocOrFree((void**)&pLevel->aInLoop,
                                 sizeof(pLevel->aInLoop[0])*3*pLevel->nIn);
    aIn = pLevel->aInLoop;
    if( aIn ){
      aIn += pLevel->nIn*3 - 3;
      aIn[0] = OP_Next;
      aIn[1] = iTab;
      aIn[2] = sqlite3VdbeAddOp(v, OP_Column, iTab, 0);

      }else{
        testOp = nEq>0 ? OP_IdxGE : OP_Noop;
        topEq = 1;
      }
      if( testOp!=OP_Noop ){
        int nCol = nEq + topLimit;
        pLevel->iMem = pParse->nMem++;
        buildIndexProbe(v, nCol, nEq, brk, pIdx);
        if( bRev ){
          int op = topEq ? OP_MoveLe : OP_MoveLt;
          sqlite3VdbeAddOp(v, op, iIdxCur, brk);
        }else{
          sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
        }
      }else if( bRev ){

        btmEq = pTerm->operator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
      }else{
        btmEq = 1;
      }
      if( nEq>0 || btmLimit ){
        int nCol = nEq + btmLimit;
        buildIndexProbe(v, nCol, 0, brk, pIdx);
        if( bRev ){
          pLevel->iMem = pParse->nMem++;
          sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
          testOp = OP_IdxLT;
        }else{
          int op = btmEq ? OP_MoveGe : OP_MoveGt;
          sqlite3VdbeAddOp(v, op, iIdxCur, brk);

      ** and leave the values of those terms on the stack.
      */
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady, brk);

      /* Generate a single key that will be used to both start and terminate
      ** the search
      */
      buildIndexProbe(v, nEq, 0, brk, pIdx);
      sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 0);

      /* Generate code (1) to move to the first matching element of the table.
      ** Then generate code (2) that jumps to "brk" after the cursor is past
      ** the last matching element of the table.  The code (1) is executed
      ** once to initialize the search, the code (2) is executed before each
      ** iteration of the scan to see if the scan has finished. */

#    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 ATTACH and DETACH commands
# and related functionality.
#
# $Id: auth.test,v 1.30 2006/01/13 13:55:45 drh Exp $
#

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

# disable this test if the SQLITE_OMIT_AUTHORIZATION macro is
# defined during compilation.

    return SQLITE_OK
  }
  execsql {
    SELECT count(a) AS cnt FROM t4 ORDER BY cnt
  }
} {1}

# Ticket #1607
#
do_test auth-5.2 {
  execsql {
    SELECT name FROM (
      SELECT * FROM sqlite_master UNION ALL SELECT * FROM sqlite_temp_master)
    WHERE type='table'
    ORDER BY name
  }
} {sqlite_stat1 t1 t2 t3 t4 tx v1chng}


rename proc {}
rename proc_real proc


finish_test

# 2003 January 29
#
# 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 testing the callback-free C/C++ API.
#
# $Id: capi3.test,v 1.38 2006/01/13 01:25:06 drh Exp $
#

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

# Return the UTF-16 representation of the supplied UTF-8 string $str.
# If $nt is true, append two 0x00 bytes as a nul terminator.

  sqlite3_errcode $DB
} {SQLITE_ERROR}
do_test capi3-1.7 {
  sqlite3_errmsg $DB
} {no such column: namex}

ifcapable {utf16} {
  do_test capi3-2.1 {
    set sql16 [utf16 {SELECT name FROM sqlite_master}]
    set STMT [sqlite3_prepare16 $DB $sql16 -1 ::TAIL]
    sqlite3_finalize $STMT
    utf8 $::TAIL
  } {}
  do_test capi3-2.2 {
    set sql [utf16 {SELECT name FROM sqlite_master;SELECT 10}]
    set STMT [sqlite3_prepare16 $DB $sql -1 TAIL]
    sqlite3_finalize $STMT
    utf8 $TAIL
  } {SELECT 10}
  do_test capi3-2.3 {
    set sql [utf16 {SELECT namex FROM sqlite_master}]
    catch {
      set STMT [sqlite3_prepare16 $DB $sql -1 TAIL]
    }
  } {1}
  do_test capi3-2.4 {
    sqlite3_errcode $DB
  } {SQLITE_ERROR}
  do_test capi3-2.5 {
    sqlite3_errmsg $DB
  } {no such column: namex}
  do_test capi3-2.6 {
    execsql {CREATE TABLE tablename(x)}
    set sql16 [utf16 {PRAGMA table_info("TableName")}]
    set STMT [sqlite3_prepare16 $DB $sql16 -1 TAIL]
    sqlite3_step $STMT
  } SQLITE_ROW
  do_test capi3-2.7 {
    sqlite3_step $STMT
  } SQLITE_DONE
  do_test capi3-2.8 {
    sqlite3_finalize $STMT
  } SQLITE_OK
} ;# endif utf16

# rename sqlite3_open sqlite3_open_old
# proc sqlite3_open {fname options} {sqlite3_open_new $fname $options}

do_test capi3-3.1 {
  set db2 [sqlite3_open test.db {}]

do_test null-3.1 {
  execsql {
    select count(*), count(b), count(c), sum(b), sum(c), 
           avg(b), avg(c), min(b), max(b) from t1;
  }
} {7 4 6 2 3 0.5 0.5 0 1}

# The sum of zero entries is a NULL, but the total of zero entries is 0.
#
do_test null-3.2 {
  execsql {
    SELECT sum(b), total(b) FROM t1 WHERE b<0
  }
} {{} 0.0}

# Check to see how WHERE clauses handle NULL values.  A NULL value
# is the same as UNKNOWN.  The WHERE clause should only select those
# rows that are TRUE.  FALSE and UNKNOWN rows are rejected.
#
do_test null-4.1 {
  execsql {
    select a from t1 where b<10

# 2001 September 15
#
# 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 file is testing the SELECT statement.
#
# $Id: select1.test,v 1.46 2006/01/13 13:01:20 danielk1977 Exp $

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

# Try to select on a non-existant table.
#
do_test select1-1.1 {

        SELECT a,b FROM t3 UNION SELECT a AS 'x', b AS 'y' FROM t4 ORDER BY a,b
      ) AS 'z' ORDER BY x;
    }
  } {x 1 x 3}
} ;# ifcapable compound


# Check for a VDBE stack growth problem that existed at one point.
#
do_test select1-13.1 {
  execsql {
    BEGIN;
    create TABLE abc(a, b, c, PRIMARY KEY(a, b));
    INSERT INTO abc VALUES(1, 1, 1);
  }
  for {set i 0} {$i<10} {incr i} {
    execsql {
      INSERT INTO abc SELECT a+(select max(a) FROM abc), 
          b+(select max(a) FROM abc), c+(select max(a) FROM abc) FROM abc;
    }
  }
  execsql {COMMIT}

  # This used to seg-fault when the problem existed.
  execsql {
    SELECT count(
      (SELECT a FROM abc WHERE a = NULL AND b >= upper.c) 
    ) FROM abc AS upper;
  }
} {0}

finish_test

#
# Run this Tcl script to generate the lang-*.html files.
#
set rcsid {$Id: lang.tcl,v 1.105 2006/01/12 22:17:50 drh Exp $}
source common.tcl

if {[llength $argv]>0} {
  set outputdir [lindex $argv 0]
} else {
  set outputdir ""
}

<td valign="top" align="right">min(<i>X</i>)</td>
<td valign="top">Return the minimum non-NULL value of all values in the group.
The usual sort order is used to determine the minimum.  NULL is only returned
if all values in the group are NULL.</td>
</tr>

<tr>
<td valign="top" align="right">sum(<i>X</i>)<br>total(<i>X</i>)</td>
<td valign="top">Return the numeric sum of all numeric values in the group.
   If there are no input rows or all values are NULL, then sum() returns
   NULL but total() returns zero.
   NULL is not a helpful result in that case (the correct answer should be
   zero) but the SQL standard requires that behavior from sum() and that is how 
   most other SQL database engines implement sum() so SQLite does it that way
   in order to be compatible.   The non-standard total() function is provided
   as a convenient way

   to work around this design problem in the SQL language.</td>
</tr>
</table>
}


Section INSERT insert