dbtupfixalloc.cpp

mysql-5.0.22.tar.gz源码包

  regPagePtr->pageWord[ZFREELIST_HEADER_POS] = (startOfList << 16) + endOfList;
}//Dbtup::convertThPage()

void Dbtup::getEmptyPageTh(Fragrecord* const regFragPtr,
                           Signal* signal,
                           Page* const regPagePtr) 
{
  if (isUndoLoggingNeeded(regFragPtr, regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS])) {
    cprAddUndoLogPageHeader(signal,
                            regPagePtr,
                            regFragPtr);
  }//if
  regPagePtr->pageWord[ZPAGE_NEXT_POS] = regFragPtr->thFreeFirst;
  regPagePtr->pageWord[ZPAGE_STATE_POS] = ZTH_MM_FREE;
  regFragPtr->thFreeFirst = regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS];

ndbrequire(regFragPtr->thFreeFirst != (RNIL -1));
}//Dbtup::getEmptyPageTh()

void Dbtup::getEmptyPageThCopy(Fragrecord* const regFragPtr,
                               Signal* signal,
                               Page* const regPagePtr) 
{
  if (isUndoLoggingNeeded(regFragPtr, regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS])) {
    cprAddUndoLogPageHeader(signal,
                            regPagePtr,
                            regFragPtr);
  }//if
  regPagePtr->pageWord[ZPAGE_NEXT_POS] = regFragPtr->thFreeCopyFirst;
  regPagePtr->pageWord[ZPAGE_STATE_POS] = ZTH_MM_FREE_COPY;
  regFragPtr->thFreeCopyFirst = regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS];
  regFragPtr->noCopyPagesAlloc++;
}//Dbtup::getEmptyPageThCopy()

void Dbtup::getThAtPage(Fragrecord* const regFragPtr,
                        Page* const regPagePtr,
                        Signal* signal,
                        Uint32& pageOffset) 
{
  Uint32 freeListHeader = regPagePtr->pageWord[ZFREELIST_HEADER_POS];
  Uint32 startTuple = freeListHeader >> 16;
  Uint32 endTuple = freeListHeader & 0xffff;
  pageOffset = startTuple;	/* START IS THE ONE ALLOCATED */
  if (startTuple > 0) {
   if (startTuple != endTuple) {
/* ---------------------------------------------------------------- */
/*       NOT THE LAST, SIMPLY RESHUFFLE POINTERS.                   */
/* ---------------------------------------------------------------- */
     ndbrequire(startTuple < ZWORDS_ON_PAGE);
     startTuple = regPagePtr->pageWord[startTuple] & 0xffff;
     regPagePtr->pageWord[ZFREELIST_HEADER_POS] = endTuple +
                                                  (startTuple << 16);
     return;
   } else {
/* ---------------------------------------------------------------- */
/*       THIS WAS THE LAST TUPLE HEADER IN THIS PAGE. REMOVE IT FROM*/
/*       THE TUPLE HEADER FREE LIST OR TH COPY FREE LIST. ALSO SET  */
/*       A PROPER PAGE STATE.                                       */
/*                                                                  */
/*       WE ALSO HAVE TO INSERT AN UNDO LOG ENTRY TO ENSURE PAGE    */
/*       ARE MAINTAINED EVEN AFTER A SYSTEM CRASH.                  */
/* ---------------------------------------------------------------- */
     if (isUndoLoggingNeeded(regFragPtr,
                             regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS])) {
       cprAddUndoLogPageHeader(signal,
                               regPagePtr,
                               regFragPtr);
     }//if
     if (regPagePtr->pageWord[ZPAGE_STATE_POS] == ZTH_MM_FREE) {
       ljam();
       regFragPtr->thFreeFirst = regPagePtr->pageWord[ZPAGE_NEXT_POS];
       regPagePtr->pageWord[ZPAGE_STATE_POS] = ZTH_MM_FULL;
     } else if (regPagePtr->pageWord[ZPAGE_STATE_POS] == ZTH_MM_FREE_COPY) {
       ljam();
       regFragPtr->thFreeCopyFirst = regPagePtr->pageWord[ZPAGE_NEXT_POS];
       regPagePtr->pageWord[ZPAGE_STATE_POS] = ZTH_MM_FULL_COPY;
     } else {
       ndbrequire(false);
     }//if
     regPagePtr->pageWord[ZFREELIST_HEADER_POS] = 0;
     regPagePtr->pageWord[ZPAGE_NEXT_POS] = RNIL;
   }//if
  } else {
    ndbrequire(false);
  }//if
  return;
}//Dbtup::getThAtPage()

void Dbtup::getThAtPageSr(Page* const regPagePtr,
                          Uint32& pageOffset) 
{
  Uint32 freeListHeader = regPagePtr->pageWord[ZFREELIST_HEADER_POS];
  Uint32 startTuple = freeListHeader >> 16;
  Uint32 endTuple = freeListHeader & 0xffff;
  ndbrequire(startTuple > 0);
  pageOffset = startTuple;	/* START IS THE ONE ALLOCATED */
  if (startTuple == endTuple) {
    ljam();
/* ---------------------------------------------------------------- */
/*       THIS WAS THE LAST TUPLE HEADER IN THIS PAGE. SINCE WE ARE  */
/*       UNDOING PAGE UPDATES WE SHALL NOT DO ANYTHING ABOUT THE    */
/*       PAGE HEADER. THIS IS DONE BY SEPARATE LOG RECORDS.         */
/* ---------------------------------------------------------------- */
    regPagePtr->pageWord[ZFREELIST_HEADER_POS] = 0;
  } else {
    ljam();
/* ---------------------------------------------------------------- */
/*       NOT THE LAST, SIMPLY RESHUFFLE POINTERS.                   */
/* ---------------------------------------------------------------- */
    ndbrequire(startTuple < ZWORDS_ON_PAGE);
    startTuple = regPagePtr->pageWord[startTuple] & 0xffff;	/* GET NEXT POINTER */
    regPagePtr->pageWord[ZFREELIST_HEADER_POS] = endTuple + (startTuple << 16);
  }//if
}//Dbtup::getThAtPageSr()

void Dbtup::freeTh(Fragrecord*  const regFragPtr,
                   Tablerec* const regTabPtr,
                   Signal* signal,
                   Page*  const regPagePtr,
                   Uint32 freePageOffset) 
{
  Uint32 startOfList = regPagePtr->pageWord[ZFREELIST_HEADER_POS] >> 16;
  Uint32 endOfList = regPagePtr->pageWord[ZFREELIST_HEADER_POS] & 0xffff;
/* LINK THE NOW FREE TUPLE SPACE INTO BEGINNING OF FREE LIST OF OF THE PAGE */
/* SET THE SIZE OF THE NEW FREE SPACE AND LINK TO THE OLD START OF FREELIST */
  ndbrequire(freePageOffset < ZWORDS_ON_PAGE);
  regPagePtr->pageWord[freePageOffset] = (regTabPtr->tupheadsize << 16) +
                                          startOfList;
  if (endOfList == 0) {
    ljam();
    ndbrequire(startOfList == 0);
/* ---------------------------------------------------------------- */
/*       THE PAGE WAS PREVIOUSLY FULL, NO EMPTY SPACE AT ALL.       */
/*       THIS ENTRY WILL THEN BE BOTH THE START AND THE END OF THE  */
/*       LIST. IT WILL ALSO BE PUT ON THE PROPER FREE LIST.         */
/*                                                                  */
/*       UPDATE OF NEXT POINTER AND PAGE STATE MUST BE LOGGED TO    */
/*       THE UNDO LOG TO ENSURE THAT FREE LISTS ARE OK AFTER A      */
/*       SYSTEM RESTART.                                            */
/* ---------------------------------------------------------------- */
    if (isUndoLoggingNeeded(regFragPtr, regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS])) {
      cprAddUndoLogPageHeader(signal,
                              regPagePtr,
                              regFragPtr);
    }//if
    regPagePtr->pageWord[ZFREELIST_HEADER_POS] = (freePageOffset << 16) + freePageOffset;
    if (regPagePtr->pageWord[ZPAGE_STATE_POS] == ZTH_MM_FULL) {
      ljam();
      regPagePtr->pageWord[ZPAGE_NEXT_POS] = regFragPtr->thFreeFirst;
      regFragPtr->thFreeFirst = regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS];	
      regPagePtr->pageWord[ZPAGE_STATE_POS] = ZTH_MM_FREE;
    } else {
      ndbrequire(regPagePtr->pageWord[ZPAGE_STATE_POS] == ZTH_MM_FULL_COPY);
      ljam();
      regPagePtr->pageWord[ZPAGE_NEXT_POS] = regFragPtr->thFreeCopyFirst;
      regFragPtr->thFreeCopyFirst = regPagePtr->pageWord[ZPAGE_FRAG_PAGE_ID_POS];
      regPagePtr->pageWord[ZPAGE_STATE_POS] = ZTH_MM_FREE_COPY;
    }//if
  } else {
    ljam();
    regPagePtr->pageWord[ZFREELIST_HEADER_POS] = (freePageOffset << 16) + endOfList;
  }//if
}//Dbtup::freeTh()

void Dbtup::freeThSr(Tablerec* const regTabPtr,
                     Page*  const regPagePtr,
                     Uint32 freePageOffset) 
{
/* ------------------------------------------------------------------------ */
/* LINK THE NOW FREE TUPLE SPACE INTO BEGINNING OF FREE LIST OF OF THE PAGE */
/* SET THE SIZE OF THE NEW FREE SPACE AND LINK TO THE OLD START OF FREELIST */
/* ------------------------------------------------------------------------ */
  Uint32 startOfList = regPagePtr->pageWord[ZFREELIST_HEADER_POS] >> 16;
  Uint32 endOfList = regPagePtr->pageWord[ZFREELIST_HEADER_POS] & 0xffff;
  ndbrequire(freePageOffset < ZWORDS_ON_PAGE);
  regPagePtr->pageWord[freePageOffset] = (regTabPtr->tupheadsize << 16) + startOfList;
  if (endOfList == 0) {
    ljam();
    ndbrequire(startOfList == 0);
/* ---------------------------------------------------------------- */
/*       THE PAGE WAS PREVIOUSLY FULL, NO EMPTY SPACE AT ALL.       */
/*       THIS ENTRY WILL THEN BE BOTH THE START AND THE END OF THE  */
/*       LIST. IT WILL ALSO BE PUT ON THE PROPER FREE LIST.         */
/* ---------------------------------------------------------------- */
    regPagePtr->pageWord[ZFREELIST_HEADER_POS] = (freePageOffset << 16) + freePageOffset;
  } else {
    ljam();
    regPagePtr->pageWord[ZFREELIST_HEADER_POS] = (freePageOffset << 16) + endOfList;
  }//if
}//Dbtup::freeThSr()