SQLite

/*
** 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 1.204 2004/11/04 14:30:05 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.

  Pgno iFreePage
){
  MemPage *pPtrPage;   /* The page that contains a pointer to pDbPage */
  Pgno iDbPage = pDbPage->pgno;
  Pager *pPager = pBt->pPager;
  int rc;

  assert( eType==PTRMAP_OVERFLOW2 || eType==PTRMAP_OVERFLOW1 || 
      eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE );

  /* Move page iDbPage from it's current location to page number iFreePage */
  TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", 
      iDbPage, iFreePage, iPtrPage, eType));
  rc = sqlite3pager_movepage(pPager, pDbPage->aData, iFreePage);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pDbPage->pgno = iFreePage;

  /* If pDbPage was a btree-page, then it may have child pages and/or cells
  ** that point to overflow pages. The pointer map entries for all these
  ** pages need to be changed.
  **
  ** If pDbPage is an overflow page, then the first 4 bytes may store a
  ** pointer to a subsequent overflow page. If this is the case, then
  ** the pointer map needs to be updated for the subsequent overflow page.
  */
  if( eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE ){
    rc = setChildPtrmaps(pDbPage);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }else{
    Pgno nextOvfl = get4byte(pDbPage->aData);
    if( nextOvfl!=0 ){
      assert( nextOvfl<=sqlite3pager_pagecount(pPager) );
      rc = ptrmapPut(pBt, nextOvfl, PTRMAP_OVERFLOW2, iFreePage);
      if( rc!=SQLITE_OK ){
        return rc;
      }
    }
  }

  /* Fix the database pointer on page iPtrPage that pointed at iDbPage so
  ** that it points at iFreePage. Also fix the pointer map entry for
  ** iPtrPage.
  */
  if( eType!=PTRMAP_ROOTPAGE ){
    rc = getPage(pBt, iPtrPage, &pPtrPage);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    rc = sqlite3pager_write(pPtrPage->aData);
    if( rc!=SQLITE_OK ){
      releasePage(pPtrPage);
      return rc;
    }
    modifyPagePointer(pPtrPage, iDbPage, iFreePage, eType);
    rc = ptrmapPut(pBt, iFreePage, eType, iPtrPage);
    releasePage(pPtrPage);
  }
  return rc;
}

/* Forward declaration required by autoVacuumCommit(). */
static int allocatePage(Btree *, MemPage **, Pgno *, Pgno);

/*

  origSize = sqlite3pager_pagecount(pPager);
  nPtrMap = (nFreeList-origSize+PTRMAP_PAGENO(pgsz, origSize)+pgsz/5)/(pgsz/5);
  finSize = origSize - nFreeList - nPtrMap;

  TRACE(("AUTOVACUUM: Begin (db size %d->%d)\n", origSize, finSize));

#if 0
  /* Note: This is temporary code for use during development of auto-vacuum. 
  **
  ** Inspect the pointer map to make sure there are no root pages with a
  ** page number greater than finSize. If so, the auto-vacuum cannot
  ** proceed. This limitation will be fixed when root pages are automatically
  ** allocated at the start of the database file.
  */
  for( i=finSize+1; i<=origSize; i++ ){
    rc = ptrmapGet(pBt, i, &eType, 0);
    if( rc!=SQLITE_OK ) goto autovacuum_out;
    if( eType==PTRMAP_ROOTPAGE ){
      TRACE(("AUTOVACUUM: Cannot proceed due to root-page on page %d\n", i));
      return SQLITE_OK;
    }
  }
#endif

  /* Variable 'finSize' will be the size of the file in pages after
  ** the auto-vacuum has completed (the current file size minus the number
  ** of pages on the free list). Loop through the pages that lie beyond
  ** this mark, and if they are not already on the free list, move them
  ** to a free page earlier in the file (somewhere before finSize).
  */

      releasePage(pPageMove);
      rc = getPage(pBt, pgnoRoot, &pRoot);
      if( rc!=SQLITE_OK ){
        return rc;
      }
      rc = ptrmapGet(pBt, pgnoRoot, &eType, &iPtrPage);
      assert( eType!=PTRMAP_ROOTPAGE );
      if( rc!=SQLITE_OK ){
        releasePage(pRoot);
        return rc;
      }
      rc = relocatePage(pBt, pRoot, eType, iPtrPage, pgnoMove);
      releasePage(pRoot);
      if( rc!=SQLITE_OK ){

** Erase all information in a table and add the root of the table to
** the freelist.  Except, the root of the principle table (the one on
** page 1) is never added to the freelist.
**
** This routine will fail with SQLITE_LOCKED if there are any open
** cursors on the table.
*/
int sqlite3BtreeDropTable(Btree *pBt, int iTable, int *piMoved){
  int rc;
  MemPage *pPage = 0;
  BtCursor *pCur;

  if( pBt->inTrans!=TRANS_WRITE ){
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }

/* TODO: Disallow schema modifications if there are open cursors */
  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
    if( pCur->pgnoRoot==(Pgno)iTable ){
      return SQLITE_LOCKED;  /* Cannot drop a table that has a cursor */
    }
  }

  rc = getPage(pBt, (Pgno)iTable, &pPage);
  if( rc ) return rc;
  rc = sqlite3BtreeClearTable(pBt, iTable);
  if( rc ) return rc;

  if( piMoved ) *piMoved = 0;

  if( iTable>1 ){
#ifdef SQLITE_OMIT_AUTOVACUUM
    rc = freePage(pPage);
    releasePage(pPage);
#else
    if( pBt->autoVacuum ){
      Pgno maxRootPgno;
      rc = sqlite3BtreeGetMeta(pBt, 4, &maxRootPgno);
      if( rc!=SQLITE_OK ){
        releasePage(pPage);
        return rc;
      }

      if( iTable==maxRootPgno ){
        /* If the table being dropped is the table with the largest root-page
        ** number in the database, put the root page on the free list. 
        */
        rc = freePage(pPage);
        releasePage(pPage);
        if( rc!=SQLITE_OK ){
          return rc;
        }
      }else{
        /* The table being dropped does not have the largest root-page
        ** number in the database. So move the page that does into the 
        ** gap left by the deleted root-page.
        */
        MemPage *pMove;
        releasePage(pPage);
        rc = getPage(pBt, maxRootPgno, &pMove);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable);
        releasePage(pMove);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        rc = getPage(pBt, maxRootPgno, &pMove);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        rc = freePage(pMove);
        releasePage(pMove);
        if( rc!=SQLITE_OK ){
          return rc;
        }
        *piMoved = maxRootPgno;
      }

      rc = sqlite3BtreeUpdateMeta(pBt, 4, maxRootPgno-1);
    }else{
      rc = freePage(pPage);
      releasePage(pPage);
    }
#endif
  }else{
    /* If sqlite3BtreeDropTable was called on page 1. */
    zeroPage(pPage, PTF_INTKEY|PTF_LEAF );
    releasePage(pPage);
  }
  return rc;  
}


/*
** Read the meta-information out of a database file.  Meta[0]
** is the number of free pages currently in the database.  Meta[1]

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.59 2004/11/04 14:30:05 danielk1977 Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

/* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR
** of the following flags:
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_ZERODATA   2    /* Table has keys only - no data */
#define BTREE_LEAFDATA   4    /* Data stored in leaves only.  Implies INTKEY */

int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int);
int sqlite3BtreeGetMeta(Btree*, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);

int sqlite3BtreeCursor(
  Btree*,                              /* BTree containing table to open */
  int iTable,                          /* Index of root page */

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.259 2004/11/04 14:30:05 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

    }
  }
  DbClearProperty(db, idx, DB_UnresetViews);
}
#else
# define sqliteViewResetAll(A,B)
#endif /* SQLITE_OMIT_VIEW */

/*
** This function is called by the VDBE to adjust the internal schema
** used by SQLite when the btree layer moves a table root page. The
** root-page of a table or index in database iDb has changed from iFrom
** to iTo.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
void sqlite3RootPageMoved(Db *pDb, int iFrom, int iTo){
  HashElem *pElem;
  
  for(pElem=sqliteHashFirst(&pDb->tblHash); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    if( pTab->tnum==iFrom ){
      pTab->tnum = iTo;
      return;
    }
  }
  for(pElem=sqliteHashFirst(&pDb->idxHash); pElem; pElem=sqliteHashNext(pElem)){
    Index *pIdx = sqliteHashData(pElem);
    if( pIdx->tnum==iFrom ){
      pIdx->tnum = iTo;
      return;
    }
  }
  assert(0);
}
#endif

/*
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Vdbe *v, int iTable, int iDb){
#ifndef SQLITE_OMIT_AUTOVACUUM
  int base;
#endif
  sqlite3VdbeAddOp(v, OP_Destroy, iTable, iDb);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* If SQLITE_OMIT_AUTOVACUUM is not defined, then OP_Destroy pushes
  ** an integer onto the stack. If this integer is non-zero, then it is
  ** the root page number of a table moved to location iTable. The 
  ** following writes VDBE code to modify the sqlite_master table to
  ** reflect this. It is assumed that cursor number 0 is a write-cursor
  ** opened on the sqlite_master table.
  */
  static const VdbeOpList updateMaster[] = {
    /* If the Op_Destroy pushed a 0 onto the stack, then skip the following
    ** code. sqlite_master does not need updating in this case.
    */
    { OP_Dup,        0, 0,        0},
    { OP_Integer,    0, 0,        0},
    { OP_Eq,         0, ADDR(17), 0},

    /* Search for the sqlite_master row containing root-page iTable. */
    { OP_Rewind,     0, ADDR(8), 0}, 
    { OP_Dup,        0, 0,       0}, /* 4 */
    { OP_Column,     0, 3,       0}, /* 5 */
    { OP_Eq,         0, ADDR(9), 0},
    { OP_Next,       0, ADDR(4), 0},
    { OP_Halt,       SQLITE_CORRUPT, OE_Fail, 0}, /* 8 */
    { OP_Recno,      0, 0,       0}, /* 9 */

    /* Cursor 0 now points at the row that will be updated. The top of
    ** the stack is the rowid of that row. The next value on the stack is 
    ** the new value for the root-page field.
    */
    { OP_Column,     0, 0,       0}, /* 10 */
    { OP_Column,     0, 1,       0},
    { OP_Column,     0, 2,       0},
    { OP_Integer,    4, 0,       0}, /* 13 */
    { OP_Column,     0, 4,       0},
    { OP_MakeRecord, 5, 0,       0},
    { OP_PutIntKey,  0, 0,       0}  /* 16 */
  };

  base = sqlite3VdbeAddOpList(v, ArraySize(updateMaster), updateMaster);
  sqlite3VdbeChangeP1(v, base+13, iTable);
#endif
}

/*
** Write VDBE code to erase table pTab and all associated indices on disk.
** Code to update the sqlite_master tables and internal schema definitions
** in case a root-page belonging to another table is moved by the btree layer
** is also added (this can happen with an auto-vacuum database).
*/
static void destroyTable(Vdbe *v, Table *pTab){
#ifdef SQLITE_OMIT_AUTOVACUUM
  destroyRootPage(v, pTab->tnum, pTab->iDb);
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    destroyRootPage(v, pIdx->tnum, pIdx->iDb);
  }
#else
  /* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM
  ** is not defined), then it is important to call OP_Destroy on the
  ** table and index root-pages in order, starting with the numerically 
  ** largest root-page number. This guarantees that none of the root-pages
  ** to be destroyed is relocated by an earlier OP_Destroy. i.e. if the
  ** following were coded:
  **
  ** OP_Destroy 4 0
  ** ...
  ** OP_Destroy 5 0
  **
  ** and root page 5 happened to be the largest root-page number in the
  ** database, then root page 5 would be moved to page 4 by the 
  ** "OP_Destroy 4 0" opcode. The subsequent "OP_Destroy 5 0" would hit
  ** a free-list page.
  */
  int iTab = pTab->tnum;
  int iDestroyed = 0;

  while( 1 ){
    Index *pIdx;
    int iLargest = 0;

    if( iDestroyed==0 || iTab<iDestroyed ){
      iLargest = iTab;
    }
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      int iIdx = pIdx->tnum;
      assert( pIdx->iDb==pTab->iDb );
      if( (iDestroyed==0 || (iIdx<iDestroyed)) && iIdx>iLargest ){
        iLargest = iIdx;
      }
    }
    if( iLargest==0 ) return;
    destroyRootPage(v, iLargest, pTab->iDb);
    iDestroyed = iLargest;
  }
#endif
}

/*
** This routine is called to do the work of a DROP TABLE statement.
** pName is the name of the table to be dropped.
*/
void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView){
  Table *pTab;

      { OP_Column,     0, 2,        0}, /* sqlite_master.type */
      { OP_Eq,         0, ADDR(12), 0},
      { OP_Delete,     0, 0,        0},
      { OP_Rewind,     0, ADDR(13), 0},
      { OP_Goto,       0, ADDR(3),  0},
      { OP_Next,       0, ADDR(3),  0}, /* 12 */
    };
    /* Index *pIdx; */
    Trigger *pTrigger;
    sqlite3BeginWriteOperation(pParse, 0, pTab->iDb);

    /* Drop all triggers associated with the table being dropped. Code
    ** is generated to remove entries from sqlite_master and/or
    ** sqlite_temp_master if required.
    */

    ** created in the temp database that refers to a table in another
    ** database.
    */
    sqlite3OpenMasterTable(v, pTab->iDb);
    base = sqlite3VdbeAddOpList(v, ArraySize(dropTable), dropTable);
    sqlite3VdbeChangeP3(v, base+1, pTab->zName, 0);
    sqlite3ChangeCookie(db, v, pTab->iDb);

    if( !isView ){
/*
      sqlite3VdbeAddOp(v, OP_Destroy, pTab->tnum, pTab->iDb);
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        sqlite3VdbeAddOp(v, OP_Destroy, pIdx->tnum, pIdx->iDb);
      }
*/
      destroyTable(v, pTab);
    }
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeOp3(v, OP_DropTable, pTab->iDb, 0, pTab->zName, 0);
  }
  sqliteViewResetAll(db, iDb);

exit_drop_table:
  sqlite3SrcListDelete(pName);
}

    int base;

    sqlite3BeginWriteOperation(pParse, 0, pIndex->iDb);
    sqlite3OpenMasterTable(v, pIndex->iDb);
    base = sqlite3VdbeAddOpList(v, ArraySize(dropIndex), dropIndex);
    sqlite3VdbeChangeP3(v, base+1, pIndex->zName, 0);
    sqlite3ChangeCookie(db, v, pIndex->iDb);
    /* sqlite3VdbeAddOp(v, OP_Destroy, pIndex->tnum, pIndex->iDb); */
    destroyRootPage(v, pIndex->tnum, pIndex->iDb);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeOp3(v, OP_DropIndex, pIndex->iDb, 0, pIndex->zName, 0);
  }

exit_drop_index:
  sqlite3SrcListDelete(pName);
}

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.172 2004/11/04 14:30:05 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  /* Mark the page as dirty.  If the page has already been written
  ** to the journal then we can return right away.
  */
  pPg->dirty = 1;
  if( pPg->inJournal && (pPg->inStmt || pPager->stmtInUse==0) ){
    pPager->dirtyCache = 1;

  }else{

    /* If we get this far, it means that the page needs to be
    ** written to the transaction journal or the ckeckpoint journal
    ** or both.
    **
    ** First check to see that the transaction journal exists and
    ** create it if it does not.
    */
    assert( pPager->state!=PAGER_UNLOCK );
    rc = sqlite3pager_begin(pData, 0);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    assert( pPager->state>=PAGER_RESERVED );
    if( !pPager->journalOpen && pPager->useJournal ){
      rc = pager_open_journal(pPager);
      if( rc!=SQLITE_OK ) return rc;
    }
    assert( pPager->journalOpen || !pPager->useJournal );
    pPager->dirtyCache = 1;
  
    /* The transaction journal now exists and we have a RESERVED or an
    ** EXCLUSIVE lock on the main database file.  Write the current page to
    ** the transaction journal if it is not there already.
    */
    if( !pPg->inJournal && (pPager->useJournal || MEMDB) ){
      if( (int)pPg->pgno <= pPager->origDbSize ){
        int szPg;
        u32 saved;
        if( MEMDB ){
          PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
          TRACE3("JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
          assert( pHist->pOrig==0 );
          pHist->pOrig = sqliteMallocRaw( pPager->pageSize );
          if( pHist->pOrig ){
            memcpy(pHist->pOrig, PGHDR_TO_DATA(pPg), pPager->pageSize);
          }
        }else{
          u32 cksum;
          CODEC(pPager, pData, pPg->pgno, 7);
          cksum = pager_cksum(pPager, pPg->pgno, pData);
          saved = *(u32*)PGHDR_TO_EXTRA(pPg, pPager);
          store32bits(cksum, pPg, pPager->pageSize);
          szPg = pPager->pageSize+8;
          store32bits(pPg->pgno, pPg, -4);
          rc = sqlite3OsWrite(&pPager->jfd, &((char*)pData)[-4], szPg);
          pPager->journalOff += szPg;
          TRACE4("JOURNAL %d page %d needSync=%d\n",
                  pPager->fd.h, pPg->pgno, pPg->needSync);
          CODEC(pPager, pData, pPg->pgno, 0);
          *(u32*)PGHDR_TO_EXTRA(pPg, pPager) = saved;
          if( rc!=SQLITE_OK ){
            sqlite3pager_rollback(pPager);
            pPager->errMask |= PAGER_ERR_FULL;
            return rc;
          }
          pPager->nRec++;
          assert( pPager->aInJournal!=0 );
          pPager->aInJournal[pPg->pgno/8] |= 1<<(pPg->pgno&7);
          pPg->needSync = !pPager->noSync;
          if( pPager->stmtInUse ){
            pPager->aInStmt[pPg->pgno/8] |= 1<<(pPg->pgno&7);
            page_add_to_stmt_list(pPg);
          }
        }
      }else{
        pPg->needSync = !pPager->journalStarted && !pPager->noSync;
        TRACE4("APPEND %d page %d needSync=%d\n",
                pPager->fd.h, pPg->pgno, pPg->needSync);
      }
      if( pPg->needSync ){
        pPager->needSync = 1;
      }
      pPg->inJournal = 1;
    }
  
    /* If the statement journal is open and the page is not in it,
    ** then write the current page to the statement journal.  Note that
    ** the statement journal format differs from the standard journal format
    ** in that it omits the checksums and the header.
    */
    if( pPager->stmtInUse && !pPg->inStmt && (int)pPg->pgno<=pPager->stmtSize ){
      assert( pPg->inJournal || (int)pPg->pgno>pPager->origDbSize );
      if( MEMDB ){
        PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
        assert( pHist->pStmt==0 );
        pHist->pStmt = sqliteMallocRaw( pPager->pageSize );
        if( pHist->pStmt ){
          memcpy(pHist->pStmt, PGHDR_TO_DATA(pPg), pPager->pageSize);
        }
        TRACE3("STMT-JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
      }else{
        store32bits(pPg->pgno, pPg, -4);
        CODEC(pPager, pData, pPg->pgno, 7);
        rc = sqlite3OsWrite(&pPager->stfd,((char*)pData)-4, pPager->pageSize+4);
        TRACE3("STMT-JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
        CODEC(pPager, pData, pPg->pgno, 0);
        if( rc!=SQLITE_OK ){
          sqlite3pager_rollback(pPager);
          pPager->errMask |= PAGER_ERR_FULL;
          return rc;
        }
        pPager->stmtNRec++;
        assert( pPager->aInStmt!=0 );
        pPager->aInStmt[pPg->pgno/8] |= 1<<(pPg->pgno&7);
      }
      page_add_to_stmt_list(pPg);
    }
  }

  /* Update the database size and return.
  */
  if( pPager->dbSize<(int)pPg->pgno ){
    pPager->dbSize = pPg->pgno;
    if( !MEMDB && pPager->dbSize==PENDING_BYTE/pPager->pageSize ){

/*
** 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 1.330 2004/11/04 14:30:05 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks

const void *sqlite3ValueText(sqlite3_value*, u8);
int sqlite3ValueBytes(sqlite3_value*, u8);
void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, void(*)(void*));
void sqlite3ValueFree(sqlite3_value*);
sqlite3_value *sqlite3ValueNew();
sqlite3_value *sqlite3GetTransientValue(sqlite3*db);
extern const unsigned char sqlite3UpperToLower[];
void sqlite3RootPageMoved(Db*, int, int);

#endif

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.54 2004/11/04 14:30:06 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  rc = sqlite3BtreeDropTable(pBt, iTable, 0);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

**
** 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 1.423 2004/11/04 14:30:06 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

** The table being destroyed is in the main database file if P2==0.  If
** P2==1 then the table to be clear is in the auxiliary database file
** that is used to store tables create using CREATE TEMPORARY TABLE.
**
** See also: Clear
*/
case OP_Destroy: {
  int iMoved;
  rc = sqlite3BtreeDropTable(db->aDb[pOp->p2].pBt, pOp->p1, &iMoved);
#ifndef SQLITE_OMIT_AUTOVACUUM
  pTos++;
  pTos->flags = MEM_Int;
  pTos->i = iMoved;
  if( iMoved!=0 ){
    sqlite3RootPageMoved(&db->aDb[pOp->p2], iMoved, pOp->p1);
  }
#endif
  break;
}

/* Opcode: Clear P1 P2 *
**
** Delete all contents of the database table or index whose root page
** in the database file is given by P1.  But, unlike Destroy, do not

# 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: autovacuum.test,v 1.6 2004/11/04 14:30:06 danielk1977 Exp $

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

# Return a string $len characters long. The returned string is $char repeated
# over and over. For example, [make_str abc 8] returns "abcabcab".
proc make_str {char len} {

  do_test autovacuum-2.$i.4 {
    execsql {
      pragma integrity_check
    }
  } {ok}
}


finish_test