int lsmFsPageSize(FileSystem *);
void lsmFsSetPageSize(FileSystem *, int);

int lsmFsFileid(lsm_db *pDb, void **ppId, int *pnId);

/* Creating, populating, gobbling and deleting sorted runs. */
void lsmFsGobble(Snapshot *, Segment *, Page *);
int lsmFsSortedDelete(FileSystem *, Snapshot *, int, Segment *);
int lsmFsSortedFinish(FileSystem *, Segment *);
int lsmFsSortedAppend(FileSystem *, Snapshot *, Segment *, Page **);
int lsmFsPhantomMaterialize(FileSystem *, Snapshot *, Segment *);

/* Functions to retrieve the lsm_env pointer from a FileSystem or Page object */
lsm_env *lsmFsEnv(FileSystem *);

int lsmFsPageSize(FileSystem *);
void lsmFsSetPageSize(FileSystem *, int);

int lsmFsFileid(lsm_db *pDb, void **ppId, int *pnId);

/* Creating, populating, gobbling and deleting sorted runs. */
void lsmFsGobble(lsm_db *, Segment *, Pgno *, int);
int lsmFsSortedDelete(FileSystem *, Snapshot *, int, Segment *);
int lsmFsSortedFinish(FileSystem *, Segment *);
int lsmFsSortedAppend(FileSystem *, Snapshot *, Segment *, Page **);
int lsmFsPhantomMaterialize(FileSystem *, Snapshot *, Segment *);

/* Functions to retrieve the lsm_env pointer from a FileSystem or Page object */
lsm_env *lsmFsEnv(FileSystem *);

}

void lsmEnvShmBarrier(lsm_env *pEnv){
  return pEnv->xShmBarrier();
}

void lsmEnvShmUnmap(lsm_env *pEnv, lsm_file *pFile, int bDel){
  return pEnv->xShmUnmap(pFile, bDel);
}

void lsmEnvSleep(lsm_env *pEnv, int nUs){
  return pEnv->xSleep(pEnv, nUs);
}


/*
** Write the contents of string buffer pStr into the log file, starting at
** offset iOff.
*/
................................................................................
    }

    if( bZero ) memset(pDel, 0, sizeof(Segment));
  }
  return LSM_OK;
}

/*
** The pager reference passed as the only argument must refer to a sorted
** file page (not a log or meta page). This call indicates that the argument
** page is now the first page in its sorted file - all previous pages may
** be considered free.
*/








void lsmFsGobble(

  Snapshot *pSnapshot,
  Segment *pRun, 
  Page *pPg

){
  FileSystem *pFS = pPg->pFS;

  if( pPg->iPg!=pRun->iFirst ){
    int rc = LSM_OK;
    int iBlk = fsPageToBlock(pFS, pRun->iFirst);
    int iFirstBlk = fsPageToBlock(pFS, pPg->iPg);

    pRun->nSize += (pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));
    pRun->iFirst = pPg->iPg;
    while( rc==LSM_OK && iBlk!=iFirstBlk ){
      int iNext = 0;
      rc = fsBlockNext(pFS, iBlk, &iNext);
      if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, 0, iBlk);
      pRun->nSize -= (
          1 + fsLastPageOnBlock(pFS, iBlk) - fsFirstPageOnBlock(pFS, iBlk)
      );
      iBlk = iNext;
    }

    pRun->nSize -= (pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));
    assert( pRun->nSize>0 );
  }
}











































/*
** The first argument to this function is a valid reference to a database
** file page that is part of a sorted run. If parameter eDir is -1, this 
** function attempts to locate and load the previous page in the same run. 
** Or, if eDir is +1, it attempts to find the next page in the same run.

}

void lsmEnvShmBarrier(lsm_env *pEnv){
  return pEnv->xShmBarrier();
}

void lsmEnvShmUnmap(lsm_env *pEnv, lsm_file *pFile, int bDel){
  pEnv->xShmUnmap(pFile, bDel);
}

void lsmEnvSleep(lsm_env *pEnv, int nUs){
  pEnv->xSleep(pEnv, nUs);
}


/*
** Write the contents of string buffer pStr into the log file, starting at
** offset iOff.
*/
................................................................................
    }

    if( bZero ) memset(pDel, 0, sizeof(Segment));
  }
  return LSM_OK;
}

static Pgno firstOnBlock(FileSystem *pFS, int iBlk, Pgno *aPgno, int nPgno){
  Pgno iRet = 0;
  int i;
  for(i=0; i<nPgno; i++){
    Pgno iPg = aPgno[i];

    if( fsPageToBlock(pFS, iPg)==iBlk && (iRet==0 || iPg<iRet) ){
      iRet = iPg;
    }
  }
  return iRet;
}

#if 0
void fsOldGobble(
  FileSystem *pFS,
  Snapshot *pSnapshot,
  Segment *pRun, 

  Pgno iPg
){


  if( iPg!=pRun->iFirst ){
    int rc = LSM_OK;
    int iBlk = fsPageToBlock(pFS, pRun->iFirst);
    int iFirstBlk = fsPageToBlock(pFS, iPg);

    pRun->nSize += (pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));
    pRun->iFirst = iPg;
    while( rc==LSM_OK && iBlk!=iFirstBlk ){
      int iNext = 0;
      rc = fsBlockNext(pFS, iBlk, &iNext);
      if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, 0, iBlk);
      pRun->nSize -= (
          1 + fsLastPageOnBlock(pFS, iBlk) - fsFirstPageOnBlock(pFS, iBlk)
          );
      iBlk = iNext;
    }

    pRun->nSize -= (pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));
    assert( pRun->nSize>0 );
  }
}
#endif

/*
** Argument aPgno is an array of nPgno page numbers. All pages belong to
** the segment pRun. This function gobbles from the start of the run to the
** first page that appears in aPgno[] (i.e. so that the aPgno[] entry is
** the new first page of the run).
*/
void lsmFsGobble(
  lsm_db *pDb,
  Segment *pRun, 
  Pgno *aPgno,
  int nPgno
){
  int rc = LSM_OK;
  FileSystem *pFS = pDb->pFS;
  Snapshot *pSnapshot = pDb->pWorker;
  int iBlk;

  assert( pRun->nSize>0 );
  iBlk = fsPageToBlock(pFS, pRun->iFirst);
  pRun->nSize += (pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));

  while( rc==LSM_OK ){
    int iNext = 0;
    Pgno iFirst = firstOnBlock(pFS, iBlk, aPgno, nPgno);
    if( iFirst ){
      pRun->iFirst = iFirst;
      break;
    }
    rc = fsBlockNext(pFS, iBlk, &iNext);
    if( rc==LSM_OK ) rc = fsFreeBlock(pFS, pSnapshot, pRun, iBlk);
    pRun->nSize -= (
        1 + fsLastPageOnBlock(pFS, iBlk) - fsFirstPageOnBlock(pFS, iBlk)
    );
    iBlk = iNext;
  }

  pRun->nSize -= (pRun->iFirst - fsFirstPageOnBlock(pFS, iBlk));
  assert( pRun->nSize>0 );
}


/*
** The first argument to this function is a valid reference to a database
** file page that is part of a sorted run. If parameter eDir is -1, this 
** function attempts to locate and load the previous page in the same run. 
** Or, if eDir is +1, it attempts to find the next page in the same run.

  lsm_db *pDb;                    /* Database handle */
  Level *pLevel;                  /* Worker snapshot Level being merged */
  MultiCursor *pCsr;              /* Cursor to read new segment contents from */
  int bFlush;                     /* True if this is an in-memory tree flush */
  Hierarchy hier;                 /* B-tree hierarchy under construction */
  Page *pPage;                    /* Current output page */
  int nWork;                      /* Number of calls to mergeWorkerNextPage() */

};

#ifdef LSM_DEBUG_EXPENSIVE
static int assertPointersOk(lsm_db *, Segment *, Segment *, int);
static int assertBtreeOk(lsm_db *, Segment *);
static void assertRunInOrder(lsm_db *pDb, Segment *pSeg);
#else
................................................................................
  assert( (void *)aKey!=pBlob->pData || nKey==pBlob->nData );
  if( (void *)aKey!=pBlob->pData ){
    rc = sortedBlobSet(pEnv, pBlob, aKey, nKey);
  }

  return rc;
}

















static int pageGetBtreeKey(
  Page *pPg,
  int iKey, 
  int *piPtr, 
  int *piTopic, 
  void **ppKey,
................................................................................
  pCsr->iCurrentPtr = iBest;
}

static int seekInBtree(
  LevelCursor *pCsr,
  Segment *pSeg,
  void *pKey, int nKey,           /* Key to seek to */

  Page **ppPg                     /* OUT: Leaf (sorted-run) page reference */
){

  int rc;
  int iPg;
  Page *pPg = 0;
  Blob blob = {0, 0, 0};
  int iTopic = 0;                 /* TODO: Fix me */

  iPg = pSeg->iRoot;
  do {






    rc = lsmFsDbPageGet(pCsr->pFS, iPg, &pPg);
    assert( rc==LSM_OK || pPg==0 );
    if( rc==LSM_OK ){
      u8 *aData;                  /* Buffer containing page data */
      int nData;                  /* Size of aData[] in bytes */
      int iMin;
      int iMax;
................................................................................
        void *pKeyT; int nKeyT;       /* Key for cell iTry */
        int iTopicT;                  /* Topic for key pKeyT/nKeyT */
        int iPtr;                     /* Pointer associated with cell iTry */
        int res;                      /* (pKey - pKeyT) */

        rc = pageGetBtreeKey(pPg, iTry, &iPtr, &iTopicT, &pKeyT, &nKeyT, &blob);
        if( rc!=LSM_OK ) break;






        res = iTopic - iTopicT;
        if( res==0 ) res = pCsr->xCmp(pKey, nKey, pKeyT, nKeyT);

        if( res<0 ){
          iPg = iPtr;
          iMax = iTry-1;
................................................................................
      lsmFsPageRelease(pPg);
      pPg = 0;
    }
  }while( rc==LSM_OK );

  sortedBlobFree(&blob);
  assert( (rc==LSM_OK)==(pPg!=0) );

  *ppPg = pPg;



  return rc;
}

static int seekInSegment(
  LevelCursor *pCsr, 
  SegmentPtr *pPtr,
  void *pKey, int nKey,
................................................................................
){
  int iPtr = iPg;
  int rc = LSM_OK;

  if( pPtr->pSeg->iRoot ){
    Page *pPg;
    assert( pPtr->pSeg->iRoot!=0 );
    rc = seekInBtree(pCsr, pPtr->pSeg, pKey, nKey, &pPg);
    if( rc==LSM_OK ) segmentPtrSetPage(pPtr, pPg);
  }else{
    if( iPtr==0 ){
      iPtr = pPtr->pSeg->iFirst;
    }
    if( rc==LSM_OK ){
      rc = segmentPtrLoadPage(pCsr->pFS, pPtr, iPtr);
................................................................................
    LevelCursor *pPtrs = &pCsr->aSegCsr[pCsr->nSegCsr-1];
    if( segmentCursorValid(pPtrs)
     && 0==pDb->xCmp(pPtrs->aPtr[0].pKey, pPtrs->aPtr[0].nKey, pKey, nKey)
    ){
      iPtr = pPtrs->aPtr[0].iPtr+pPtrs->aPtr[0].iPgPtr;
    }
  }











  /* If this is a separator key and we know that the output pointer has not
  ** changed, there is no point in writing an output record. Otherwise,
  ** proceed. */
  if( rtIsSeparator(eType)==0 || iPtr!=0 ){
    int iSPtr = 0;                /* Separators require a pointer here */

................................................................................
}

static int mergeWorkerInit(
  lsm_db *pDb,                    /* Db connection to do merge work */
  Level *pLevel,                  /* Level to work on merging */
  MergeWorker *pMW                /* Object to initialize */
){
  int rc;                         /* Return code */
  Merge *pMerge = pLevel->pMerge; /* Persistent part of merge state */
  MultiCursor *pCsr = 0;          /* Cursor opened for pMW */

  assert( pDb->pWorker );
  assert( pLevel->pMerge );
  assert( pLevel->nRight>0 );

  memset(pMW, 0, sizeof(MergeWorker));
  pMW->pDb = pDb;
  pMW->pLevel = pLevel;


  /* Create a multi-cursor to read the data to write to the new
  ** segment. The new segment contains:
  **
  **   1. Records from LHS of each of the nMerge levels being merged.
  **   2. Separators from either the last level being merged, or the
  **      separators attached to the LHS of the following level, or neither.
  **
  ** If the new level is the lowest (oldest) in the db, discard any
  ** delete keys. Key annihilation.
  */

  rc = multiCursorNew(pDb, pDb->pWorker, TREE_NONE, 0, &pCsr);

  if( rc==LSM_OK ){
    rc = multiCursorAddLevel(pCsr, pLevel, MULTICURSOR_ADDLEVEL_RHS);
  }
  if( rc==LSM_OK && pLevel->pNext ){
    if( pMerge->nInput > pLevel->nRight ){
      Level *pNext = pLevel->pNext;
      rc = multiCursorAddLevel(pCsr, pNext, MULTICURSOR_ADDLEVEL_LHS_SEP);
................................................................................
      }
    }
    pCsr->flags |= CURSOR_NEXT_OK;
  }

  return rc;
}
































/*
** Argument p points to a level of age N. Return the number of levels in
** the linked list starting at p that have age=N (always at least 1).
*/
static int sortedCountLevels(Level *p){
  int iAge = p->iAge;
................................................................................
      **
      ** Otherwise, gobble up (declare eligible for recycling) any pages
      ** from rhs segments for which the content has been completely merged
      ** into the lhs of the level.
      */
      if( rc==LSM_OK ){
        if( mergeWorkerDone(&mergeworker)==0 ){










          int iGobble = mergeworker.pCsr->aTree[1] - CURSOR_DATA_SEGMENT;
          if( iGobble<pLevel->nRight ){
            SegmentPtr *pGobble = &mergeworker.pCsr->aSegCsr[iGobble].aPtr[0];


            if( (pGobble->flags & PGFTR_SKIP_THIS_FLAG)==0 

             && pGobble->pSeg->iRoot==0
            ){
              lsmFsGobble(pWorker, pGobble->pSeg, pGobble->pPg);
            }
          }


        }else if( pLevel->lhs.iFirst==0 ){
          /* If the new level is completely empty, remove it from the 
          ** database snapshot. This can only happen if all input keys were
          ** annihilated. Since keys are only annihilated if the new level
          ** is the last in the linked list (contains the most ancient of
          ** database content), this guarantees that pLevel->pNext==0.  */ 
................................................................................
int lsmSortedAutoWork(
  lsm_db *pDb,                    /* Database handle */
  int nUnit                       /* Pages of data written to in-memory tree */
){
  int rc;                         /* Return code */
  int nRemaining;                 /* Units of work to do before returning */
  int nDepth = 0;                 /* Current height of tree (longest path) */
  int nWrite;                     /* Pages written */
  Level *pLevel;                  /* Used to iterate through levels */
  int bRestore = 0;

  assert( pDb->pWorker==0 );
  assert( pDb->nTransOpen>0 );

  /* Determine how many units of work to do before returning. One unit of
................................................................................
      rc = lsmCheckpointDeserialize(pDb, 0, pDb->aSnapshot, &pDb->pClient);
    }
    if( rc==LSM_OK ){
      rc = lsmRestoreCursors(pDb);
    }
  }

#if 0
  lsmLogMessage(pDb, 0, "auto-work: %d pages", nWrite);
#endif

  return rc;
}

/*
** This function is only called during system shutdown. The contents of
** any in-memory trees present (old or current) are written out to disk.
*/

  lsm_db *pDb;                    /* Database handle */
  Level *pLevel;                  /* Worker snapshot Level being merged */
  MultiCursor *pCsr;              /* Cursor to read new segment contents from */
  int bFlush;                     /* True if this is an in-memory tree flush */
  Hierarchy hier;                 /* B-tree hierarchy under construction */
  Page *pPage;                    /* Current output page */
  int nWork;                      /* Number of calls to mergeWorkerNextPage() */
  Pgno *aGobble;                  /* Gobble point for each input segment */
};

#ifdef LSM_DEBUG_EXPENSIVE
static int assertPointersOk(lsm_db *, Segment *, Segment *, int);
static int assertBtreeOk(lsm_db *, Segment *);
static void assertRunInOrder(lsm_db *pDb, Segment *pSeg);
#else
................................................................................
  assert( (void *)aKey!=pBlob->pData || nKey==pBlob->nData );
  if( (void *)aKey!=pBlob->pData ){
    rc = sortedBlobSet(pEnv, pBlob, aKey, nKey);
  }

  return rc;
}

static Pgno pageGetBtreeRef(Page *pPg, int iKey){
  Pgno iRef;
  u8 *aData;
  int nData;
  u8 *aCell;

  aData = fsPageData(pPg, &nData);
  aCell = pageGetCell(aData, nData, iKey);
  assert( aCell[0]==0 );
  aCell++;
  aCell += lsmVarintGet32(aCell, &iRef);
  lsmVarintGet32(aCell, &iRef);
  assert( iRef>0 );
  return iRef;
}

static int pageGetBtreeKey(
  Page *pPg,
  int iKey, 
  int *piPtr, 
  int *piTopic, 
  void **ppKey,
................................................................................
  pCsr->iCurrentPtr = iBest;
}

static int seekInBtree(
  LevelCursor *pCsr,
  Segment *pSeg,
  void *pKey, int nKey,           /* Key to seek to */
  Pgno *aPg,                      /* OUT: Page numbers */
  Page **ppPg                     /* OUT: Leaf (sorted-run) page reference */
){
  int i = 0;
  int rc;
  int iPg;
  Page *pPg = 0;
  Blob blob = {0, 0, 0};
  int iTopic = 0;                 /* TODO: Fix me */

  iPg = pSeg->iRoot;
  do {
    Pgno *piFirst = 0;
    if( aPg ){
      aPg[i++] = iPg;
      piFirst = &aPg[i];
    }

    rc = lsmFsDbPageGet(pCsr->pFS, iPg, &pPg);
    assert( rc==LSM_OK || pPg==0 );
    if( rc==LSM_OK ){
      u8 *aData;                  /* Buffer containing page data */
      int nData;                  /* Size of aData[] in bytes */
      int iMin;
      int iMax;
................................................................................
        void *pKeyT; int nKeyT;       /* Key for cell iTry */
        int iTopicT;                  /* Topic for key pKeyT/nKeyT */
        int iPtr;                     /* Pointer associated with cell iTry */
        int res;                      /* (pKey - pKeyT) */

        rc = pageGetBtreeKey(pPg, iTry, &iPtr, &iTopicT, &pKeyT, &nKeyT, &blob);
        if( rc!=LSM_OK ) break;
        if( piFirst && pKeyT==blob.pData ){
          *piFirst = pageGetBtreeRef(pPg, iTry);
          piFirst = 0;
          i++;
        }

        res = iTopic - iTopicT;
        if( res==0 ) res = pCsr->xCmp(pKey, nKey, pKeyT, nKeyT);

        if( res<0 ){
          iPg = iPtr;
          iMax = iTry-1;
................................................................................
      lsmFsPageRelease(pPg);
      pPg = 0;
    }
  }while( rc==LSM_OK );

  sortedBlobFree(&blob);
  assert( (rc==LSM_OK)==(pPg!=0) );
  if( ppPg ){
    *ppPg = pPg;
  }else{
    lsmFsPageRelease(pPg);
  }
  return rc;
}

static int seekInSegment(
  LevelCursor *pCsr, 
  SegmentPtr *pPtr,
  void *pKey, int nKey,
................................................................................
){
  int iPtr = iPg;
  int rc = LSM_OK;

  if( pPtr->pSeg->iRoot ){
    Page *pPg;
    assert( pPtr->pSeg->iRoot!=0 );
    rc = seekInBtree(pCsr, pPtr->pSeg, pKey, nKey, 0, &pPg);
    if( rc==LSM_OK ) segmentPtrSetPage(pPtr, pPg);
  }else{
    if( iPtr==0 ){
      iPtr = pPtr->pSeg->iFirst;
    }
    if( rc==LSM_OK ){
      rc = segmentPtrLoadPage(pCsr->pFS, pPtr, iPtr);
................................................................................
    LevelCursor *pPtrs = &pCsr->aSegCsr[pCsr->nSegCsr-1];
    if( segmentCursorValid(pPtrs)
     && 0==pDb->xCmp(pPtrs->aPtr[0].pKey, pPtrs->aPtr[0].nKey, pKey, nKey)
    ){
      iPtr = pPtrs->aPtr[0].iPtr+pPtrs->aPtr[0].iPgPtr;
    }
  }

  if( pMW->aGobble ){
    int iGobble = pCsr->aTree[1] - CURSOR_DATA_SEGMENT;
    if( iGobble<pMW->pLevel->nRight ){
      SegmentPtr *pGobble = &pCsr->aSegCsr[iGobble].aPtr[0];
      if( (pGobble->flags & PGFTR_SKIP_THIS_FLAG)==0 ){
        pMW->aGobble[iGobble] = lsmFsPageNumber(pGobble->pPg);
      }
    }
  }

  /* If this is a separator key and we know that the output pointer has not
  ** changed, there is no point in writing an output record. Otherwise,
  ** proceed. */
  if( rtIsSeparator(eType)==0 || iPtr!=0 ){
    int iSPtr = 0;                /* Separators require a pointer here */

................................................................................
}

static int mergeWorkerInit(
  lsm_db *pDb,                    /* Db connection to do merge work */
  Level *pLevel,                  /* Level to work on merging */
  MergeWorker *pMW                /* Object to initialize */
){
  int rc = LSM_OK;                /* Return code */
  Merge *pMerge = pLevel->pMerge; /* Persistent part of merge state */
  MultiCursor *pCsr = 0;          /* Cursor opened for pMW */

  assert( pDb->pWorker );
  assert( pLevel->pMerge );
  assert( pLevel->nRight>0 );

  memset(pMW, 0, sizeof(MergeWorker));
  pMW->pDb = pDb;
  pMW->pLevel = pLevel;
  pMW->aGobble = lsmMallocZeroRc(pDb->pEnv, sizeof(Pgno) * pLevel->nRight, &rc);

  /* Create a multi-cursor to read the data to write to the new
  ** segment. The new segment contains:
  **
  **   1. Records from LHS of each of the nMerge levels being merged.
  **   2. Separators from either the last level being merged, or the
  **      separators attached to the LHS of the following level, or neither.
  **
  ** If the new level is the lowest (oldest) in the db, discard any
  ** delete keys. Key annihilation.
  */
  if( rc==LSM_OK ){
    rc = multiCursorNew(pDb, pDb->pWorker, TREE_NONE, 0, &pCsr);
  }
  if( rc==LSM_OK ){
    rc = multiCursorAddLevel(pCsr, pLevel, MULTICURSOR_ADDLEVEL_RHS);
  }
  if( rc==LSM_OK && pLevel->pNext ){
    if( pMerge->nInput > pLevel->nRight ){
      Level *pNext = pLevel->pNext;
      rc = multiCursorAddLevel(pCsr, pNext, MULTICURSOR_ADDLEVEL_LHS_SEP);
................................................................................
      }
    }
    pCsr->flags |= CURSOR_NEXT_OK;
  }

  return rc;
}

static int sortedBtreeGobble(
  lsm_db *pDb, 
  MultiCursor *pCsr, 
  int iGobble
){
  int rc = LSM_OK;
  if( rtTopic(pCsr->eType)==0 ){
    LevelCursor *pLvlcsr = &pCsr->aSegCsr[iGobble];
    Segment *pSeg = pLvlcsr->aPtr[0].pSeg;
    Blob *p = &pCsr->key;
    Pgno *aPg;
    int nPg;

    assert( pLvlcsr->nPtr==1 );
    assert( pSeg->iRoot>0 );

    aPg = lsmMallocZeroRc(pDb->pEnv, sizeof(Pgno)*32, &rc);
    if( rc==LSM_OK ){
      rc = seekInBtree(pLvlcsr, pSeg, p->pData, p->nData, aPg, 0); 
    }

    for(nPg=0; aPg[nPg]; nPg++);
#if 1
    lsmFsGobble(pDb, pSeg, aPg, nPg);
#endif

    lsmFree(pDb->pEnv, aPg);
  }
  return rc;
}

/*
** Argument p points to a level of age N. Return the number of levels in
** the linked list starting at p that have age=N (always at least 1).
*/
static int sortedCountLevels(Level *p){
  int iAge = p->iAge;
................................................................................
      **
      ** Otherwise, gobble up (declare eligible for recycling) any pages
      ** from rhs segments for which the content has been completely merged
      ** into the lhs of the level.
      */
      if( rc==LSM_OK ){
        if( mergeWorkerDone(&mergeworker)==0 ){
          int i;
          for(i=0; i<pLevel->nRight; i++){
            SegmentPtr *pGobble = &mergeworker.pCsr->aSegCsr[i].aPtr[0];
            if( pGobble->pSeg->iRoot ){
              rc = sortedBtreeGobble(pDb, mergeworker.pCsr, i);
            }else if( mergeworker.aGobble[i] ){
              lsmFsGobble(pDb, pGobble->pSeg, &mergeworker.aGobble[i], 1);
            }
          }
#if 0
          int iGobble = mergeworker.pCsr->aTree[1] - CURSOR_DATA_SEGMENT;
          if( iGobble<pLevel->nRight ){
            SegmentPtr *pGobble = &mergeworker.pCsr->aSegCsr[iGobble].aPtr[0];
            if( pGobble->pSeg->iRoot ){
              rc = sortedBtreeGobble(pDb, mergeworker.pCsr, iGobble);
            }else if( (pGobble->flags & PGFTR_SKIP_THIS_FLAG)==0 ){
              Pgno iPg = lsmFsPageNumber(pGobble->pPg);
              lsmFsGobble(pDb, pGobble->pSeg, &iPg, 1);


            }
          }
#endif

        }else if( pLevel->lhs.iFirst==0 ){
          /* If the new level is completely empty, remove it from the 
          ** database snapshot. This can only happen if all input keys were
          ** annihilated. Since keys are only annihilated if the new level
          ** is the last in the linked list (contains the most ancient of
          ** database content), this guarantees that pLevel->pNext==0.  */ 
................................................................................
int lsmSortedAutoWork(
  lsm_db *pDb,                    /* Database handle */
  int nUnit                       /* Pages of data written to in-memory tree */
){
  int rc;                         /* Return code */
  int nRemaining;                 /* Units of work to do before returning */
  int nDepth = 0;                 /* Current height of tree (longest path) */

  Level *pLevel;                  /* Used to iterate through levels */
  int bRestore = 0;

  assert( pDb->pWorker==0 );
  assert( pDb->nTransOpen>0 );

  /* Determine how many units of work to do before returning. One unit of
................................................................................
      rc = lsmCheckpointDeserialize(pDb, 0, pDb->aSnapshot, &pDb->pClient);
    }
    if( rc==LSM_OK ){
      rc = lsmRestoreCursors(pDb);
    }
  }





  return rc;
}

/*
** This function is only called during system shutdown. The contents of
** any in-memory trees present (old or current) are written out to disk.
*/

  append script $data2
  append script $data3

  append script "pause -1\n"
  exec_gnuplot_script $script $zPng
}

do_write_test x.png 120 50000 0 30 {
  lsm-mt    "mmap=1 multi_proc=0 threads=3 autowork=0 autocheckpoint=0"
  leveldb   leveldb
}

#  lsm-mt    "mmap=1 multi_proc=0 threads=2 autowork=0 autocheckpoint=8192000"
# lsm-mt     "mmap=1 multi_proc=0 safety=1 threads=3 autowork=0"
# lsm-st     "mmap=1 multi_proc=0 safety=1 threads=1 autowork=1"

  append script $data2
  append script $data3

  append script "pause -1\n"
  exec_gnuplot_script $script $zPng
}

do_write_test x.png 120 50000 50000 30 {
  lsm-mt    "mmap=1 multi_proc=0 threads=3 autowork=0 autocheckpoint=0"
  leveldb   leveldb
}

#  lsm-mt    "mmap=1 multi_proc=0 threads=2 autowork=0 autocheckpoint=8192000"
# lsm-mt     "mmap=1 multi_proc=0 safety=1 threads=3 autowork=0"
# lsm-st     "mmap=1 multi_proc=0 safety=1 threads=1 autowork=1"