internal static RC relocatePage(BtShared pBt, MemPage pDbPage, PTRMAP eType, Pgno iPtrPage, Pgno iFreePage, int isCommit)
{
var pPtrPage = new MemPage(); // The page that contains a pointer to pDbPage
var iDbPage = pDbPage.ID;
var pPager = pBt.Pager;
Debug.Assert(eType == PTRMAP.OVERFLOW2 || eType == PTRMAP.OVERFLOW1 || eType == PTRMAP.BTREE || eType == PTRMAP.ROOTPAGE);
Debug.Assert(MutexEx.Held(pBt.Mutex));
Debug.Assert(pDbPage.Shared == pBt);
// Move page iDbPage from its current location to page number iFreePage
Btree.TRACE("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", iDbPage, iFreePage, iPtrPage, eType);
var rc = pPager.sqlite3PagerMovepage(pDbPage.DbPage, iFreePage, isCommit);
if (rc != RC.OK)
{
return(rc);
}
pDbPage.ID = 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 = pDbPage.setChildPtrmaps();
if (rc != RC.OK)
{
return(rc);
}
}
else
{
var nextOvfl = (Pgno)ConvertEx.Get4(pDbPage.Data);
if (nextOvfl != 0)
{
pBt.ptrmapPut(nextOvfl, PTRMAP.OVERFLOW2, iFreePage, ref rc);
if (rc != RC.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 = pBt.btreeGetPage(iPtrPage, ref pPtrPage, 0);
if (rc != RC.OK)
{
return(rc);
}
rc = Pager.Write(pPtrPage.DbPage);
if (rc != RC.OK)
{
pPtrPage.releasePage();
return(rc);
}
rc = pPtrPage.modifyPagePointer(iDbPage, iFreePage, eType);
pPtrPage.releasePage();
if (rc == RC.OK)
{
pBt.ptrmapPut(iFreePage, eType, iPtrPage, ref rc);
}
}
return(rc);
}
internal static RC relocatePage(BtShared pBt, MemPage pDbPage, PTRMAP eType, Pgno iPtrPage, Pgno iFreePage, int isCommit)
{
var pPtrPage = new MemPage(); // The page that contains a pointer to pDbPage
var iDbPage = pDbPage.ID;
var pPager = pBt.Pager;
Debug.Assert(eType == PTRMAP.OVERFLOW2 || eType == PTRMAP.OVERFLOW1 || eType == PTRMAP.BTREE || eType == PTRMAP.ROOTPAGE);
Debug.Assert(MutexEx.Held(pBt.Mutex));
Debug.Assert(pDbPage.Shared == pBt);
// Move page iDbPage from its current location to page number iFreePage
Btree.TRACE("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", iDbPage, iFreePage, iPtrPage, eType);
var rc = pPager.sqlite3PagerMovepage(pDbPage.DbPage, iFreePage, isCommit);
if (rc != RC.OK)
return rc;
pDbPage.ID = 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 = pDbPage.setChildPtrmaps();
if (rc != RC.OK)
return rc;
}
else
{
var nextOvfl = (Pgno)ConvertEx.Get4(pDbPage.Data);
if (nextOvfl != 0)
{
pBt.ptrmapPut(nextOvfl, PTRMAP.OVERFLOW2, iFreePage, ref rc);
if (rc != RC.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 = pBt.btreeGetPage(iPtrPage, ref pPtrPage, 0);
if (rc != RC.OK)
return rc;
rc = Pager.Write(pPtrPage.DbPage);
if (rc != RC.OK)
{
pPtrPage.releasePage();
return rc;
}
rc = pPtrPage.modifyPagePointer(iDbPage, iFreePage, eType);
pPtrPage.releasePage();
if (rc == RC.OK)
pBt.ptrmapPut(iFreePage, eType, iPtrPage, ref rc);
}
return rc;
}
