private static RC subjournalPage(PgHdr pPg)
{
var rc = RC.OK;
var pPager = pPg.Pager;
if (pPager.journalMode != JOURNALMODE.OFF)
{
// Open the sub-journal, if it has not already been opened
Debug.Assert(pPager.useJournal != 0);
Debug.Assert(pPager.jfd.IsOpen || pPager.pagerUseWal());
Debug.Assert(pPager.sjfd.IsOpen || pPager.nSubRec == 0);
Debug.Assert(pPager.pagerUseWal() || pageInJournal(pPg) || pPg.ID > pPager.dbOrigSize);
rc = pPager.openSubJournal();
// If the sub-journal was opened successfully (or was already open), write the journal record into the file.
if (rc == RC.OK)
{
var pData = pPg.Data;
long offset = pPager.nSubRec * (4 + pPager.pageSize);
byte[] pData2 = null;
if (CODEC2(pPager, pData, pPg.ID, codec_ctx.ENCRYPT_READ_CTX, ref pData2))
return RC.NOMEM;
PAGERTRACE("STMT-JOURNAL {0} page {1}", PAGERID(pPager), pPg.ID);
rc = pPager.sjfd.WriteByte(offset, pPg.ID);
if (rc == RC.OK)
rc = pPager.sjfd.Write(pData2, pPager.pageSize, offset + 4);
}
}
if (rc == RC.OK)
{
pPager.nSubRec++;
Debug.Assert(pPager.nSavepoint > 0);
rc = pPager.addToSavepointBitvecs(pPg.ID);
}
return rc;
}
private static void pcacheRemoveFromDirtyList(PgHdr pPage)
{
var p = pPage.Cache;
Debug.Assert(pPage.DirtyNext != null || pPage == p.pDirtyTail);
Debug.Assert(pPage.DirtyPrev != null || pPage == p.pDirty);
// Update the PCache1.pSynced variable if necessary.
if (p.pSynced == pPage)
{
var pSynced = pPage.DirtyPrev;
while (pSynced != null && (pSynced.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
pSynced = pSynced.DirtyPrev;
p.pSynced = pSynced;
}
if (pPage.DirtyNext != null)
pPage.DirtyNext.DirtyPrev = pPage.DirtyPrev;
else
{
Debug.Assert(pPage == p.pDirtyTail);
p.pDirtyTail = pPage.DirtyPrev;
}
if (pPage.DirtyPrev != null)
pPage.DirtyPrev.DirtyNext = pPage.DirtyNext;
else
{
Debug.Assert(pPage == p.pDirty);
p.pDirty = pPage.DirtyNext;
}
pPage.DirtyNext = null;
pPage.DirtyPrev = null;
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(p));
#endif
}
public PgHdr pPage1; // Reference to page 1
public void ClearState()
{
pDirty = null;
pDirtyTail = null;
pSynced = null;
nRef = 0;
}
private static void pcacheUnpin(PgHdr p)
{
var pCache = p.Cache;
if (pCache.bPurgeable)
{
if (p.ID == 1)
pCache.pPage1 = null;
pCache.pCache.xUnpin(p, false);
}
}
// was:sqlite3PcacheMakeClean
internal static void MakePageClean(PgHdr p)
{
if ((p.Flags & PgHdr.PGHDR.DIRTY) != 0)
{
pcacheRemoveFromDirtyList(p);
p.Flags &= ~(PgHdr.PGHDR.DIRTY | PgHdr.PGHDR.NEED_SYNC);
if (p.Refs == 0)
pcacheUnpin(p);
}
}
// was:sqlite3PcacheMakeDirty
internal static void MakePageDirty(PgHdr p)
{
p.Flags &= ~PgHdr.PGHDR.DONT_WRITE;
Debug.Assert(p.Refs > 0);
if (0 == (p.Flags & PgHdr.PGHDR.DIRTY))
{
p.Flags |= PgHdr.PGHDR.DIRTY;
pcacheAddToDirtyList(p);
}
}
// was:sqlite3PagerDontWrite
public static void DontWrite(PgHdr pPg)
{
var pPager = pPg.Pager;
if ((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0 && pPager.nSavepoint == 0)
{
PAGERTRACE("DONT_WRITE page {0} of {1}", pPg.ID, PAGERID(pPager));
SysEx.IOTRACE("CLEAN {0:x} {1}", pPager.GetHashCode(), pPg.ID);
pPg.Flags |= PgHdr.PGHDR.DONT_WRITE;
pager_set_pagehash(pPg);
}
}
// was:sqlite3PcacheDrop
internal static void DropPage(PgHdr p)
{
PCache pCache;
Debug.Assert(p.Refs == 1);
if ((p.Flags & PgHdr.PGHDR.DIRTY) != 0)
pcacheRemoveFromDirtyList(p);
pCache = p.Cache;
pCache.nRef--;
if (p.ID == 1)
pCache.pPage1 = null;
pCache.pCache.xUnpin(p, true);
}
// was:sqlite3PcacheMove
internal static void MovePage(PgHdr p, Pgno newPgno)
{
PCache pCache = p.Cache;
Debug.Assert(p.Refs > 0);
Debug.Assert(newPgno > 0);
pCache.pCache.xRekey(p, p.ID, newPgno);
p.ID = newPgno;
if ((p.Flags & PgHdr.PGHDR.DIRTY) != 0 && (p.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
pcacheRemoveFromDirtyList(p);
pcacheAddToDirtyList(p);
}
}
public void ClearState()
{
this.Data = null;
this.Extra = null;
this.Dirtys = null;
this.ID = 0;
this.Pager = null;
#if DEBUG
this.PageHash = 0;
#endif
this.Flags = 0;
this.Refs = 0;
this.CacheAllocated = false;
this.Cache = null;
this.DirtyNext = null;
this.DirtyPrev = null;
this.PgHdr1 = null;
}
private static void pcacheAddToDirtyList(PgHdr pPage)
{
var p = pPage.Cache;
Debug.Assert(pPage.DirtyNext == null && pPage.DirtyPrev == null && p.pDirty != pPage);
pPage.DirtyNext = p.pDirty;
if (pPage.DirtyNext != null)
{
Debug.Assert(pPage.DirtyNext.DirtyPrev == null);
pPage.DirtyNext.DirtyPrev = pPage;
}
p.pDirty = pPage;
if (null == p.pDirtyTail)
p.pDirtyTail = pPage;
if (null == p.pSynced && 0 == (pPage.Flags & PgHdr.PGHDR.NEED_SYNC))
p.pSynced = pPage;
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(p));
#endif
}
// was:sqlite3PcacheRelease
internal static void ReleasePage(PgHdr p)
{
Debug.Assert(p.Refs > 0);
p.Refs--;
if (p.Refs == 0)
{
var pCache = p.Cache;
pCache.nRef--;
if ((p.Flags & PgHdr.PGHDR.DIRTY) == 0)
{
pcacheUnpin(p);
}
else
{
// Move the page to the head of the dirty list.
pcacheRemoveFromDirtyList(p);
pcacheAddToDirtyList(p);
}
}
}
private static void pcacheRemoveFromDirtyList(PgHdr pPage)
{
var p = pPage.Cache;
Debug.Assert(pPage.DirtyNext != null || pPage == p.pDirtyTail);
Debug.Assert(pPage.DirtyPrev != null || pPage == p.pDirty);
// Update the PCache1.pSynced variable if necessary.
if (p.pSynced == pPage)
{
var pSynced = pPage.DirtyPrev;
while (pSynced != null && (pSynced.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
pSynced = pSynced.DirtyPrev;
}
p.pSynced = pSynced;
}
if (pPage.DirtyNext != null)
{
pPage.DirtyNext.DirtyPrev = pPage.DirtyPrev;
}
else
{
Debug.Assert(pPage == p.pDirtyTail);
p.pDirtyTail = pPage.DirtyPrev;
}
if (pPage.DirtyPrev != null)
{
pPage.DirtyPrev.DirtyNext = pPage.DirtyNext;
}
else
{
Debug.Assert(pPage == p.pDirty);
p.pDirty = pPage.DirtyNext;
}
pPage.DirtyNext = null;
pPage.DirtyPrev = null;
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(p));
#endif
}
private static RC subjournalPage(PgHdr pPg)
{
var rc = RC.OK;
var pPager = pPg.Pager;
if (pPager.journalMode != JOURNALMODE.OFF)
{
// Open the sub-journal, if it has not already been opened
Debug.Assert(pPager.useJournal != 0);
Debug.Assert(pPager.jfd.IsOpen || pPager.pagerUseWal());
Debug.Assert(pPager.sjfd.IsOpen || pPager.nSubRec == 0);
Debug.Assert(pPager.pagerUseWal() || pageInJournal(pPg) || pPg.ID > pPager.dbOrigSize);
rc = pPager.openSubJournal();
// If the sub-journal was opened successfully (or was already open), write the journal record into the file.
if (rc == RC.OK)
{
var pData = pPg.Data;
long offset = pPager.nSubRec * (4 + pPager.pageSize);
byte[] pData2 = null;
if (CODEC2(pPager, pData, pPg.ID, codec_ctx.ENCRYPT_READ_CTX, ref pData2))
{
return(RC.NOMEM);
}
PAGERTRACE("STMT-JOURNAL {0} page {1}", PAGERID(pPager), pPg.ID);
rc = pPager.sjfd.WriteByte(offset, pPg.ID);
if (rc == RC.OK)
{
rc = pPager.sjfd.Write(pData2, pPager.pageSize, offset + 4);
}
}
}
if (rc == RC.OK)
{
pPager.nSubRec++;
Debug.Assert(pPager.nSavepoint > 0);
rc = pPager.addToSavepointBitvecs(pPg.ID);
}
return(rc);
}
// This function is called to rollback a transaction on a WAL database.
static int pagerRollbackWal(Pager pPager)
{
int rc; /* Return Code */
PgHdr pList; /* List of dirty pages to revert */
/* For all pages in the cache that are currently dirty or have already been written (but not committed) to the log file, do one of the
** following:
** + Discard the cached page (if refcount==0), or
** + Reload page content from the database (if refcount>0).
*/
pPager.dbSize = pPager.dbOrigSize;
rc = sqlite3WalUndo(pPager.pWal, pagerUndoCallback, pPager);
pList = sqlite3PcacheDirtyList(pPager.pPCache);
while (pList && rc == SQLITE.OK)
{
PgHdr pNext = pList.pDirty;
rc = pagerUndoCallback(pPager, pList.pgno);
pList = pNext;
}
return(rc);
}
private static PgHdr pcacheSortDirtyList(PgHdr pIn)
{
var a = new PgHdr[N_SORT_BUCKET];
PgHdr p;
while (pIn != null)
{
p = pIn;
pIn = p.Dirtys;
p.Dirtys = null;
int i;
for (i = 0; Check.ALWAYS(i < N_SORT_BUCKET - 1); i++)
{
if (a[i] == null)
{
a[i] = p;
break;
}
else
{
p = pcacheMergeDirtyList(a[i], p);
a[i] = null;
}
}
if (Check.NEVER(i == N_SORT_BUCKET - 1))
{
// To get here, there need to be 2^(N_SORT_BUCKET) elements in the input list. But that is impossible.
a[i] = pcacheMergeDirtyList(a[i], p);
}
}
p = a[0];
for (var i = 1; i < N_SORT_BUCKET; i++)
{
p = pcacheMergeDirtyList(p, a[i]);
}
return(p);
}
private static void pcacheAddToDirtyList(PgHdr pPage)
{
var p = pPage.Cache;
Debug.Assert(pPage.DirtyNext == null && pPage.DirtyPrev == null && p.pDirty != pPage);
pPage.DirtyNext = p.pDirty;
if (pPage.DirtyNext != null)
{
Debug.Assert(pPage.DirtyNext.DirtyPrev == null);
pPage.DirtyNext.DirtyPrev = pPage;
}
p.pDirty = pPage;
if (null == p.pDirtyTail)
{
p.pDirtyTail = pPage;
}
if (null == p.pSynced && 0 == (pPage.Flags & PgHdr.PGHDR.NEED_SYNC))
{
p.pSynced = pPage;
}
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(p));
#endif
}
private static PgHdr pcacheMergeDirtyList(PgHdr pA, PgHdr pB)
{
var result = new PgHdr();
var pTail = result;
while (pA != null && pB != null)
{
if (pA.ID < pB.ID)
{
pTail.Dirtys = pA;
pTail = pA;
pA = pA.Dirtys;
}
else
{
pTail.Dirtys = pB;
pTail = pB;
pB = pB.Dirtys;
}
}
if (pA != null)
pTail.Dirtys = pA;
else if (pB != null)
pTail.Dirtys = pB;
else
pTail.Dirtys = null;
return result.Dirtys;
}
internal static int sqlite3PcachePageRefcount(PgHdr p)
{
return p.Refs;
}
internal static void assertTruncateConstraintCb(PgHdr pPg)
{
}
internal static void pager_set_pagehash(PgHdr X)
{
}
internal static void pager_set_pagehash(PgHdr pPage)
{
pPage.PageHash = pager_pagehash(pPage);
}
internal RC pagerWalFrames(PgHdr w, Pgno x, int y, VirtualFile.SYNC z)
{
return(RC.OK);
}
internal static void assertTruncateConstraintCb(PgHdr pPg)
{
}
private static bool pageInJournal(PgHdr pPg)
{
return pPg.Pager.pInJournal.Get(pPg.ID) != 0;
}
private static bool subjRequiresPage(PgHdr pPg)
{
var pgno = pPg.ID;
var pPager = pPg.Pager;
for (var i = 0; i < pPager.nSavepoint; i++)
{
var p = pPager.aSavepoint[i];
if (p.nOrig >= pgno && p.pInSavepoint.Get(pgno) == 0)
return true;
}
return false;
}
internal static int sqlite3PcachePageRefcount(PgHdr p)
{
return(p.Refs);
}
// was:sqlite3PcacheFetch
internal RC FetchPage(Pgno pgno, int createFlag, ref PgHdr ppPage)
{
Debug.Assert(createFlag == 1 || createFlag == 0);
Debug.Assert(pgno > 0);
// If the pluggable cache (sqlite3_pcache*) has not been allocated, allocate it now.
if (pCache == null && createFlag != 0)
{
var nByte = szPage + szExtra + 0;
var p = IPCache.xCreate(nByte, bPurgeable);
p.xCachesize(nMax);
pCache = p;
}
var eCreate = createFlag * (1 + ((!bPurgeable || null == pDirty) ? 1 : 0));
PgHdr pPage = null;
if (pCache != null)
{
pPage = pCache.xFetch(pgno, eCreate);
}
if (pPage == null && eCreate == 1)
{
PgHdr pPg;
// Find a dirty page to write-out and recycle. First try to find a page that does not require a journal-sync (one with PGHDR_NEED_SYNC
// cleared), but if that is not possible settle for any other unreferenced dirty page.
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(pCache));
#endif
for (pPg = pSynced; pPg != null && (pPg.Refs != 0 || (pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0); pPg = pPg.DirtyPrev)
{
;
}
pSynced = pPg;
if (pPg == null)
{
for (pPg = pDirtyTail; pPg != null && pPg.Refs != 0; pPg = pPg.DirtyPrev)
{
;
}
}
if (pPg != null)
{
#if SQLITE_LOG_CACHE_SPILL
sqlite3_log(SQLITE_FULL, "spill page %d making room for %d - cache used: %d/%d", pPg.pgno, pgno, sqlite3GlobalConfig.pcache.xPagecount(pCache.pCache), pCache.nMax);
#endif
var rc = xStress(pStress, pPg);
if (rc != RC.OK && rc != RC.BUSY)
{
return(rc);
}
}
pPage = pCache.xFetch(pgno, 2);
}
if (pPage != null)
{
if (pPage.Data == null)
{
pPage.Data = MallocEx.sqlite3Malloc(pCache.szPage);
pPage.Cache = this;
pPage.ID = pgno;
}
Debug.Assert(pPage.Cache == this);
Debug.Assert(pPage.ID == pgno);
if (pPage.Refs == 0)
{
nRef++;
}
pPage.Refs++;
if (pgno == 1)
{
pPage1 = pPage;
}
}
ppPage = pPage;
return(pPage == null && eCreate != 0 ? RC.NOMEM : RC.OK);
}
private static PgHdr pcacheSortDirtyList(PgHdr pIn)
{
var a = new PgHdr[N_SORT_BUCKET];
PgHdr p;
while (pIn != null)
{
p = pIn;
pIn = p.Dirtys;
p.Dirtys = null;
int i;
for (i = 0; Check.ALWAYS(i < N_SORT_BUCKET - 1); i++)
{
if (a[i] == null)
{
a[i] = p;
break;
}
else
{
p = pcacheMergeDirtyList(a[i], p);
a[i] = null;
}
}
if (Check.NEVER(i == N_SORT_BUCKET - 1))
// To get here, there need to be 2^(N_SORT_BUCKET) elements in the input list. But that is impossible.
a[i] = pcacheMergeDirtyList(a[i], p);
}
p = a[0];
for (var i = 1; i < N_SORT_BUCKET; i++)
p = pcacheMergeDirtyList(p, a[i]);
return p;
}
internal RC ptrmapGet(Pgno key, ref PTRMAP pEType, ref Pgno pPgno)
{
Debug.Assert(MutexEx.Held(this.Mutex));
var iPtrmap = (int)MemPage.PTRMAP_PAGENO(this, key);
var pDbPage = new PgHdr(); // The pointer map page
var rc = this.Pager.Get((Pgno)iPtrmap, ref pDbPage);
if (rc != RC.OK)
return rc;
var pPtrmap = Pager.sqlite3PagerGetData(pDbPage);// Pointer map page data
var offset = (int)MemPage.PTRMAP_PTROFFSET((Pgno)iPtrmap, key);
if (offset < 0)
{
Pager.Unref(pDbPage);
return SysEx.SQLITE_CORRUPT_BKPT();
}
Debug.Assert(offset <= (int)this.UsableSize - 5);
var v = pPtrmap[offset];
if (v < 1 || v > 5)
return SysEx.SQLITE_CORRUPT_BKPT();
pEType = (PTRMAP)v;
pPgno = ConvertEx.Get4(pPtrmap, offset + 1);
Pager.Unref(pDbPage);
return RC.OK;
}
// was:sqlite3PagerWrite
public static RC Write(DbPage pDbPage)
{
var rc = RC.OK;
var pPg = pDbPage;
var pPager = pPg.Pager;
var nPagePerSector = (uint)(pPager.sectorSize / pPager.pageSize);
Debug.Assert(pPager.eState >= PAGER.WRITER_LOCKED);
Debug.Assert(pPager.eState != PAGER.ERROR);
Debug.Assert(pPager.assert_pager_state());
if (nPagePerSector > 1)
{
Pgno nPageCount = 0; // Total number of pages in database file
Pgno pg1; // First page of the sector pPg is located on.
Pgno nPage = 0; // Number of pages starting at pg1 to journal
bool needSync = false; // True if any page has PGHDR_NEED_SYNC
// Set the doNotSyncSpill flag to 1. This is because we cannot allow a journal header to be written between the pages journaled by
// this function.
Debug.Assert(
#if SQLITE_OMIT_MEMORYDB
0 == MEMDB
#else
0 == pPager.memDb
#endif
);
Debug.Assert(pPager.doNotSyncSpill == 0);
pPager.doNotSyncSpill++;
// This trick assumes that both the page-size and sector-size are an integer power of 2. It sets variable pg1 to the identifier
// of the first page of the sector pPg is located on.
pg1 = (Pgno)((pPg.ID - 1) & ~(nPagePerSector - 1)) + 1;
nPageCount = pPager.dbSize;
if (pPg.ID > nPageCount)
{
nPage = (pPg.ID - pg1) + 1;
}
else if ((pg1 + nPagePerSector - 1) > nPageCount)
{
nPage = nPageCount + 1 - pg1;
}
else
{
nPage = nPagePerSector;
}
Debug.Assert(nPage > 0);
Debug.Assert(pg1 <= pPg.ID);
Debug.Assert((pg1 + nPage) > pPg.ID);
for (var ii = 0; ii < nPage && rc == RC.OK; ii++)
{
var pg = (Pgno)(pg1 + ii);
var pPage = new PgHdr();
if (pg == pPg.ID || pPager.pInJournal.Get(pg) == 0)
{
if (pg != ((VirtualFile.PENDING_BYTE / (pPager.pageSize)) + 1))
{
rc = pPager.Get(pg, ref pPage);
if (rc == RC.OK)
{
rc = pager_write(pPage);
if ((pPage.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
needSync = true;
}
Unref(pPage);
}
}
}
else if ((pPage = pPager.pager_lookup(pg)) != null)
{
if ((pPage.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
needSync = true;
}
Unref(pPage);
}
}
// If the PGHDR_NEED_SYNC flag is set for any of the nPage pages starting at pg1, then it needs to be set for all of them. Because
// writing to any of these nPage pages may damage the others, the journal file must contain sync()ed copies of all of them
// before any of them can be written out to the database file.
if (rc == RC.OK && needSync)
{
Debug.Assert(
#if SQLITE_OMIT_MEMORYDB
0 == MEMDB
#else
0 == pPager.memDb
#endif
);
for (var ii = 0; ii < nPage; ii++)
{
var pPage = pPager.pager_lookup((Pgno)(pg1 + ii));
if (pPage != null)
{
pPage.Flags |= PgHdr.PGHDR.NEED_SYNC;
Unref(pPage);
}
}
}
Debug.Assert(pPager.doNotSyncSpill == 1);
pPager.doNotSyncSpill--;
}
else
{
rc = pager_write(pDbPage);
}
return(rc);
}
internal void ptrmapPut(Pgno key, PTRMAP eType, Pgno parent, ref RC rRC)
{
if (rRC != RC.OK)
return;
Debug.Assert(MutexEx.Held(this.Mutex));
// The master-journal page number must never be used as a pointer map page
Debug.Assert(!MemPage.PTRMAP_ISPAGE(this, MemPage.PENDING_BYTE_PAGE(this)));
Debug.Assert(this.AutoVacuum);
if (key == 0)
{
rRC = SysEx.SQLITE_CORRUPT_BKPT();
return;
}
var iPtrmap = MemPage.PTRMAP_PAGENO(this, key);
var pDbPage = new PgHdr(); // The pointer map page
var rc = this.Pager.Get(iPtrmap, ref pDbPage);
if (rc != RC.OK)
{
rRC = rc;
return;
}
var offset = (int)MemPage.PTRMAP_PTROFFSET(iPtrmap, key);
if (offset < 0)
{
rRC = SysEx.SQLITE_CORRUPT_BKPT();
goto ptrmap_exit;
}
Debug.Assert(offset <= (int)this.UsableSize - 5);
var pPtrmap = Pager.sqlite3PagerGetData(pDbPage); // The pointer map data
if (eType != (PTRMAP)pPtrmap[offset] || ConvertEx.Get4(pPtrmap, offset + 1) != parent)
{
Btree.TRACE("PTRMAP_UPDATE: {0}->({1},{2})", key, eType, parent);
rRC = rc = Pager.Write(pDbPage);
if (rc == RC.OK)
{
pPtrmap[offset] = (byte)eType;
ConvertEx.Put4L(pPtrmap, offset + 1, parent);
}
}
ptrmap_exit:
Pager.Unref(pDbPage);
}
/*
** This function is called by the wal module when writing page content
** into the log file.
**
** This function returns a pointer to a buffer containing the encrypted
** page content. If a malloc fails, this function may return NULL.
*/
void sqlite3PagerCodec(PgHdr *pPg)
{
voidaData = 0;
CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
return aData;
}
// was:sqlite3PcacheRef
internal static void AddPageRef(PgHdr p)
{
Debug.Assert(p.Refs > 0); p.Refs++;
}
internal static uint pager_pagehash(PgHdr pPage)
{
return(pager_datahash(pPage.Pager.pageSize, pPage.Data));
}
private RC pager_write_pagelist(PgHdr pList)
{
var rc = RC.OK;
// This function is only called for rollback pagers in WRITER_DBMOD state.
Debug.Assert(!pagerUseWal());
Debug.Assert(this.eState == PAGER.WRITER_DBMOD);
Debug.Assert(this.eLock == VFSLOCK.EXCLUSIVE);
// If the file is a temp-file has not yet been opened, open it now. It is not possible for rc to be other than SQLITE.OK if this branch
// is taken, as pager_wait_on_lock() is a no-op for temp-files.
if (!this.fd.IsOpen)
{
Debug.Assert(this.tempFile && rc == RC.OK);
rc = pagerOpentemp(ref this.fd, this.vfsFlags);
}
// Before the first write, give the VFS a hint of what the final file size will be.
Debug.Assert(rc != RC.OK || this.fd.IsOpen);
if (rc == RC.OK && this.dbSize > this.dbHintSize)
{
long szFile = this.pageSize * (long)this.dbSize;
this.fd.SetFileControl(VirtualFile.FCNTL.SIZE_HINT, ref szFile);
this.dbHintSize = this.dbSize;
}
while (rc == RC.OK && pList)
{
var pgno = pList.ID;
// If there are dirty pages in the page cache with page numbers greater than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to
// make the file smaller (presumably by auto-vacuum code). Do not write any such pages to the file.
// Also, do not write out any page that has the PGHDR_DONT_WRITE flag set (set by sqlite3PagerDontWrite()).
if (pList.ID <= this.dbSize && 0 == (pList.Flags & PgHdr.PGHDR.DONT_WRITE))
{
Debug.Assert((pList.Flags & PgHdr.PGHDR.NEED_SYNC) == 0);
if (pList.ID == 1)
{
pager_write_changecounter(pList);
}
// Encode the database
byte[] pData = null; // Data to write
if (CODEC2(this, pList.Data, pgno, codec_ctx.ENCRYPT_WRITE_CTX, ref pData))
{
return(RC.NOMEM);
}
// Write out the page data.
long offset = (pList.ID - 1) * (long)this.pageSize; // Offset to write
rc = this.fd.Write(pData, this.pageSize, offset);
// If page 1 was just written, update Pager.dbFileVers to match the value now stored in the database file. If writing this
// page caused the database file to grow, update dbFileSize.
if (pgno == 1)
{
Buffer.BlockCopy(pData, 24, this.dbFileVers, 0, this.dbFileVers.Length);
}
if (pgno > this.dbFileSize)
{
this.dbFileSize = pgno;
}
// Update any backup objects copying the contents of this pager.
if (this.pBackup != null)
{
this.pBackup.sqlite3BackupUpdate(pgno, pList.Data);
}
PAGERTRACE("STORE {0} page {1} hash({2,08:x})", PAGERID(this), pgno, pager_pagehash(pList));
SysEx.IOTRACE("PGOUT {0:x} {1}", this.GetHashCode(), pgno);
}
else
{
PAGERTRACE("NOSTORE {0} page {1}", PAGERID(this), pgno);
}
pager_set_pagehash(pList);
pList = pList.Dirtys;
}
return(rc);
}
internal static uint pager_pagehash(PgHdr X)
{
return(0);
}
private RC pager_incr_changecounter(bool isDirectMode)
{
var rc = RC.OK;
Debug.Assert(this.eState == PAGER.WRITER_CACHEMOD || this.eState == PAGER.WRITER_DBMOD);
Debug.Assert(assert_pager_state());
// Declare and initialize constant integer 'isDirect'. If the atomic-write optimization is enabled in this build, then isDirect
// is initialized to the value passed as the isDirectMode parameter to this function. Otherwise, it is always set to zero.
// The idea is that if the atomic-write optimization is not enabled at compile time, the compiler can omit the tests of
// 'isDirect' below, as well as the block enclosed in the "if( isDirect )" condition.
#if !SQLITE_ENABLE_ATOMIC_WRITE
var DIRECT_MODE = false;
Debug.Assert(!isDirectMode);
SysEx.UNUSED_PARAMETER(isDirectMode);
#else
var DIRECT_MODE = isDirectMode;
#endif
if (!this.changeCountDone && this.dbSize > 0)
{
PgHdr pPgHdr = null; // Reference to page 1
Debug.Assert(!this.tempFile && this.fd.IsOpen);
// Open page 1 of the file for writing.
rc = Get(1, ref pPgHdr);
Debug.Assert(pPgHdr == null || rc == RC.OK);
// If page one was fetched successfully, and this function is not operating in direct-mode, make page 1 writable. When not in
// direct mode, page 1 is always held in cache and hence the PagerGet() above is always successful - hence the ALWAYS on rc==SQLITE.OK.
if (!DIRECT_MODE && Check.ALWAYS(rc == RC.OK))
{
rc = Write(pPgHdr);
}
if (rc == RC.OK)
{
// Actually do the update of the change counter
pager_write_changecounter(pPgHdr);
// If running in direct mode, write the contents of page 1 to the file.
if (DIRECT_MODE)
{
byte[] zBuf = null;
Debug.Assert(this.dbFileSize > 0);
if (CODEC2(this, pPgHdr.Data, 1, codec_ctx.ENCRYPT_WRITE_CTX, ref zBuf))
{
return(rc = RC.NOMEM);
}
if (rc == RC.OK)
{
rc = this.fd.Write(zBuf, this.pageSize, 0);
}
if (rc == RC.OK)
{
this.changeCountDone = true;
}
}
else
{
this.changeCountDone = true;
}
}
// Release the page reference.
Unref(pPgHdr);
}
return(rc);
}
internal static void assertTruncateConstraintCb(PgHdr pPg)
{
Debug.Assert((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0); Debug.Assert(!subjRequiresPage(pPg) || pPg.ID <= pPg.Pager.dbSize);
}
private static RC pagerStress(object p, PgHdr pPg)
{
var pPager = (Pager)p;
var rc = RC.OK;
Debug.Assert(pPg.Pager == pPager);
Debug.Assert((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0);
// The doNotSyncSpill flag is set during times when doing a sync of journal (and adding a new header) is not allowed. This occurs
// during calls to sqlite3PagerWrite() while trying to journal multiple pages belonging to the same sector.
// The doNotSpill flag inhibits all cache spilling regardless of whether or not a sync is required. This is set during a rollback.
// Spilling is also prohibited when in an error state since that could lead to database corruption. In the current implementaton it
// is impossible for sqlite3PCacheFetch() to be called with createFlag==1 while in the error state, hence it is impossible for this routine to
// be called in the error state. Nevertheless, we include a NEVER() test for the error state as a safeguard against future changes.
if (Check.NEVER(pPager.errCode != 0))
{
return(RC.OK);
}
if (pPager.doNotSpill != 0)
{
return(RC.OK);
}
if (pPager.doNotSyncSpill != 0 && (pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
return(RC.OK);
}
pPg.Dirtys = null;
if (pPager.pagerUseWal())
{
// Write a single frame for this page to the log.
if (subjRequiresPage(pPg))
{
rc = subjournalPage(pPg);
}
if (rc == RC.OK)
{
rc = pPager.pagerWalFrames(pPg, 0, 0, 0);
}
}
else
{
// Sync the journal file if required.
if ((pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0 || pPager.eState == PAGER.WRITER_CACHEMOD)
{
rc = pPager.syncJournal(1);
}
// If the page number of this page is larger than the current size of the database image, it may need to be written to the sub-journal.
// This is because the call to pager_write_pagelist() below will not actually write data to the file in this case.
// Consider the following sequence of events:
// BEGIN;
// <journal page X>
// <modify page X>
// SAVEPOINT sp;
// <shrink database file to Y pages>
// pagerStress(page X)
// ROLLBACK TO sp;
// If (X>Y), then when pagerStress is called page X will not be written out to the database file, but will be dropped from the cache. Then,
// following the "ROLLBACK TO sp" statement, reading page X will read data from the database file. This will be the copy of page X as it
// was when the transaction started, not as it was when "SAVEPOINT sp" was executed.
// The solution is to write the current data for page X into the sub-journal file now (if it is not already there), so that it will
// be restored to its current value when the "ROLLBACK TO sp" is executed.
if (Check.NEVER(rc == RC.OK && pPg.ID > pPager.dbSize && subjRequiresPage(pPg)))
{
rc = subjournalPage(pPg);
}
// Write the contents of the page out to the database file.
if (rc == RC.OK)
{
Debug.Assert((pPg.Flags & PgHdr.PGHDR.NEED_SYNC) == 0);
rc = pPager.pager_write_pagelist(pPg);
}
}
// Mark the page as clean.
if (rc == RC.OK)
{
PAGERTRACE("STRESS {0} page {1}", PAGERID(pPager), pPg.ID);
PCache.MakePageClean(pPg);
}
return(pPager.pager_error(rc));
}
// was:sqlite3PcacheRelease
internal static void ReleasePage(PgHdr p)
{
Debug.Assert(p.Refs > 0);
p.Refs--;
if (p.Refs == 0)
{
var pCache = p.Cache;
pCache.nRef--;
if ((p.Flags & PgHdr.PGHDR.DIRTY) == 0)
pcacheUnpin(p);
else
{
// Move the page to the head of the dirty list.
pcacheRemoveFromDirtyList(p);
pcacheAddToDirtyList(p);
}
}
}
private RC pager_write_pagelist(PgHdr pList)
{
var rc = RC.OK;
// This function is only called for rollback pagers in WRITER_DBMOD state.
Debug.Assert(!pagerUseWal());
Debug.Assert(this.eState == PAGER.WRITER_DBMOD);
Debug.Assert(this.eLock == VFSLOCK.EXCLUSIVE);
// If the file is a temp-file has not yet been opened, open it now. It is not possible for rc to be other than SQLITE.OK if this branch
// is taken, as pager_wait_on_lock() is a no-op for temp-files.
if (!this.fd.IsOpen)
{
Debug.Assert(this.tempFile && rc == RC.OK);
rc = pagerOpentemp(ref this.fd, this.vfsFlags);
}
// Before the first write, give the VFS a hint of what the final file size will be.
Debug.Assert(rc != RC.OK || this.fd.IsOpen);
if (rc == RC.OK && this.dbSize > this.dbHintSize)
{
long szFile = this.pageSize * (long)this.dbSize;
this.fd.SetFileControl(VirtualFile.FCNTL.SIZE_HINT, ref szFile);
this.dbHintSize = this.dbSize;
}
while (rc == RC.OK && pList)
{
var pgno = pList.ID;
// If there are dirty pages in the page cache with page numbers greater than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to
// make the file smaller (presumably by auto-vacuum code). Do not write any such pages to the file.
// Also, do not write out any page that has the PGHDR_DONT_WRITE flag set (set by sqlite3PagerDontWrite()).
if (pList.ID <= this.dbSize && 0 == (pList.Flags & PgHdr.PGHDR.DONT_WRITE))
{
Debug.Assert((pList.Flags & PgHdr.PGHDR.NEED_SYNC) == 0);
if (pList.ID == 1)
pager_write_changecounter(pList);
// Encode the database
byte[] pData = null; // Data to write
if (CODEC2(this, pList.Data, pgno, codec_ctx.ENCRYPT_WRITE_CTX, ref pData))
return RC.NOMEM;
// Write out the page data.
long offset = (pList.ID - 1) * (long)this.pageSize; // Offset to write
rc = this.fd.Write(pData, this.pageSize, offset);
// If page 1 was just written, update Pager.dbFileVers to match the value now stored in the database file. If writing this
// page caused the database file to grow, update dbFileSize.
if (pgno == 1)
Buffer.BlockCopy(pData, 24, this.dbFileVers, 0, this.dbFileVers.Length);
if (pgno > this.dbFileSize)
this.dbFileSize = pgno;
// Update any backup objects copying the contents of this pager.
if (this.pBackup != null)
this.pBackup.sqlite3BackupUpdate(pgno, pList.Data);
PAGERTRACE("STORE {0} page {1} hash({2,08:x})", PAGERID(this), pgno, pager_pagehash(pList));
SysEx.IOTRACE("PGOUT {0:x} {1}", this.GetHashCode(), pgno);
}
else
PAGERTRACE("NOSTORE {0} page {1}", PAGERID(this), pgno);
pager_set_pagehash(pList);
pList = pList.Dirtys;
}
return rc;
}
// was:sqlite3PcacheFetch
internal RC FetchPage(Pgno pgno, int createFlag, ref PgHdr ppPage)
{
Debug.Assert(createFlag == 1 || createFlag == 0);
Debug.Assert(pgno > 0);
// If the pluggable cache (sqlite3_pcache*) has not been allocated, allocate it now.
if (pCache == null && createFlag != 0)
{
var nByte = szPage + szExtra + 0;
var p = IPCache.xCreate(nByte, bPurgeable);
p.xCachesize(nMax);
pCache = p;
}
var eCreate = createFlag * (1 + ((!bPurgeable || null == pDirty) ? 1 : 0));
PgHdr pPage = null;
if (pCache != null)
pPage = pCache.xFetch(pgno, eCreate);
if (pPage == null && eCreate == 1)
{
PgHdr pPg;
// Find a dirty page to write-out and recycle. First try to find a page that does not require a journal-sync (one with PGHDR_NEED_SYNC
// cleared), but if that is not possible settle for any other unreferenced dirty page.
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(pCache));
#endif
for (pPg = pSynced; pPg != null && (pPg.Refs != 0 || (pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0); pPg = pPg.DirtyPrev) ;
pSynced = pPg;
if (pPg == null)
for (pPg = pDirtyTail; pPg != null && pPg.Refs != 0; pPg = pPg.DirtyPrev) ;
if (pPg != null)
{
#if SQLITE_LOG_CACHE_SPILL
sqlite3_log(SQLITE_FULL, "spill page %d making room for %d - cache used: %d/%d", pPg.pgno, pgno, sqlite3GlobalConfig.pcache.xPagecount(pCache.pCache), pCache.nMax);
#endif
var rc = xStress(pStress, pPg);
if (rc != RC.OK && rc != RC.BUSY)
return rc;
}
pPage = pCache.xFetch(pgno, 2);
}
if (pPage != null)
{
if (pPage.Data == null)
{
pPage.Data = MallocEx.sqlite3Malloc(pCache.szPage);
pPage.Cache = this;
pPage.ID = pgno;
}
Debug.Assert(pPage.Cache == this);
Debug.Assert(pPage.ID == pgno);
if (pPage.Refs == 0)
nRef++;
pPage.Refs++;
if (pgno == 1)
pPage1 = pPage;
}
ppPage = pPage;
return (pPage == null && eCreate != 0 ? RC.NOMEM : RC.OK);
}
private static RC pagerStress(object p, PgHdr pPg)
{
var pPager = (Pager)p;
var rc = RC.OK;
Debug.Assert(pPg.Pager == pPager);
Debug.Assert((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0);
// The doNotSyncSpill flag is set during times when doing a sync of journal (and adding a new header) is not allowed. This occurs
// during calls to sqlite3PagerWrite() while trying to journal multiple pages belonging to the same sector.
// The doNotSpill flag inhibits all cache spilling regardless of whether or not a sync is required. This is set during a rollback.
// Spilling is also prohibited when in an error state since that could lead to database corruption. In the current implementaton it
// is impossible for sqlite3PCacheFetch() to be called with createFlag==1 while in the error state, hence it is impossible for this routine to
// be called in the error state. Nevertheless, we include a NEVER() test for the error state as a safeguard against future changes.
if (Check.NEVER(pPager.errCode != 0))
return RC.OK;
if (pPager.doNotSpill != 0)
return RC.OK;
if (pPager.doNotSyncSpill != 0 && (pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
return RC.OK;
pPg.Dirtys = null;
if (pPager.pagerUseWal())
{
// Write a single frame for this page to the log.
if (subjRequiresPage(pPg))
rc = subjournalPage(pPg);
if (rc == RC.OK)
rc = pPager.pagerWalFrames(pPg, 0, 0, 0);
}
else
{
// Sync the journal file if required.
if ((pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0 || pPager.eState == PAGER.WRITER_CACHEMOD)
rc = pPager.syncJournal(1);
// If the page number of this page is larger than the current size of the database image, it may need to be written to the sub-journal.
// This is because the call to pager_write_pagelist() below will not actually write data to the file in this case.
// Consider the following sequence of events:
// BEGIN;
// <journal page X>
// <modify page X>
// SAVEPOINT sp;
// <shrink database file to Y pages>
// pagerStress(page X)
// ROLLBACK TO sp;
// If (X>Y), then when pagerStress is called page X will not be written out to the database file, but will be dropped from the cache. Then,
// following the "ROLLBACK TO sp" statement, reading page X will read data from the database file. This will be the copy of page X as it
// was when the transaction started, not as it was when "SAVEPOINT sp" was executed.
// The solution is to write the current data for page X into the sub-journal file now (if it is not already there), so that it will
// be restored to its current value when the "ROLLBACK TO sp" is executed.
if (Check.NEVER(rc == RC.OK && pPg.ID > pPager.dbSize && subjRequiresPage(pPg)))
rc = subjournalPage(pPg);
// Write the contents of the page out to the database file.
if (rc == RC.OK)
{
Debug.Assert((pPg.Flags & PgHdr.PGHDR.NEED_SYNC) == 0);
rc = pPager.pager_write_pagelist(pPg);
}
}
// Mark the page as clean.
if (rc == RC.OK)
{
PAGERTRACE("STRESS {0} page {1}", PAGERID(pPager), pPg.ID);
PCache.MakePageClean(pPg);
}
return pPager.pager_error(rc);
}
// was:sqlite3PcacheRef
internal static void AddPageRef(PgHdr p)
{
Debug.Assert(p.Refs > 0); p.Refs++;
}
// was:sqlite3PagerWrite
public static RC Write(DbPage pDbPage)
{
var rc = RC.OK;
var pPg = pDbPage;
var pPager = pPg.Pager;
var nPagePerSector = (uint)(pPager.sectorSize / pPager.pageSize);
Debug.Assert(pPager.eState >= PAGER.WRITER_LOCKED);
Debug.Assert(pPager.eState != PAGER.ERROR);
Debug.Assert(pPager.assert_pager_state());
if (nPagePerSector > 1)
{
Pgno nPageCount = 0; // Total number of pages in database file
Pgno pg1; // First page of the sector pPg is located on.
Pgno nPage = 0; // Number of pages starting at pg1 to journal
bool needSync = false; // True if any page has PGHDR_NEED_SYNC
// Set the doNotSyncSpill flag to 1. This is because we cannot allow a journal header to be written between the pages journaled by
// this function.
Debug.Assert(
#if SQLITE_OMIT_MEMORYDB
0==MEMDB
#else
0 == pPager.memDb
#endif
);
Debug.Assert(pPager.doNotSyncSpill == 0);
pPager.doNotSyncSpill++;
// This trick assumes that both the page-size and sector-size are an integer power of 2. It sets variable pg1 to the identifier
// of the first page of the sector pPg is located on.
pg1 = (Pgno)((pPg.ID - 1) & ~(nPagePerSector - 1)) + 1;
nPageCount = pPager.dbSize;
if (pPg.ID > nPageCount)
nPage = (pPg.ID - pg1) + 1;
else if ((pg1 + nPagePerSector - 1) > nPageCount)
nPage = nPageCount + 1 - pg1;
else
nPage = nPagePerSector;
Debug.Assert(nPage > 0);
Debug.Assert(pg1 <= pPg.ID);
Debug.Assert((pg1 + nPage) > pPg.ID);
for (var ii = 0; ii < nPage && rc == RC.OK; ii++)
{
var pg = (Pgno)(pg1 + ii);
var pPage = new PgHdr();
if (pg == pPg.ID || pPager.pInJournal.Get(pg) == 0)
{
if (pg != ((VirtualFile.PENDING_BYTE / (pPager.pageSize)) + 1))
{
rc = pPager.Get(pg, ref pPage);
if (rc == RC.OK)
{
rc = pager_write(pPage);
if ((pPage.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
needSync = true;
Unref(pPage);
}
}
}
else if ((pPage = pPager.pager_lookup(pg)) != null)
{
if ((pPage.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
needSync = true;
Unref(pPage);
}
}
// If the PGHDR_NEED_SYNC flag is set for any of the nPage pages starting at pg1, then it needs to be set for all of them. Because
// writing to any of these nPage pages may damage the others, the journal file must contain sync()ed copies of all of them
// before any of them can be written out to the database file.
if (rc == RC.OK && needSync)
{
Debug.Assert(
#if SQLITE_OMIT_MEMORYDB
0==MEMDB
#else
0 == pPager.memDb
#endif
);
for (var ii = 0; ii < nPage; ii++)
{
var pPage = pPager.pager_lookup((Pgno)(pg1 + ii));
if (pPage != null)
{
pPage.Flags |= PgHdr.PGHDR.NEED_SYNC;
Unref(pPage);
}
}
}
Debug.Assert(pPager.doNotSyncSpill == 1);
pPager.doNotSyncSpill--;
}
else
rc = pager_write(pDbPage);
return rc;
}
private static bool pageInJournal(PgHdr pPg)
{
return(pPg.Pager.pInJournal.Get(pPg.ID));
}
/*
** This function is a wrapper around sqlite3WalFrames(). As well as logging
** the contents of the list of pages headed by pList (connected by pDirty),
** this function notifies any active backup processes that the pages have
** changed.
**
** The list of pages passed into this routine is always sorted by page number.
** Hence, if page 1 appears anywhere on the list, it will be the first page.
*/
static int pagerWalFrames(Pager pPager, PgHdr pList, Pgno nTruncate, int isCommit, int syncFlags)
{
int rc; /* Return code */
#if DEBUG || (SQLITE_CHECK_PAGES)
PgHdr p; /* For looping over pages */
#endif
Debug.Assert(pPager.pWal);
#if SQLITE_DEBUG
/* Verify that the page list is in accending order */
for(p=pList; p && p->pDirty; p=p->pDirty){
assert( p->pgno < p->pDirty->pgno );
}
#endif
if (isCommit)
{
/* If a WAL transaction is being committed, there is no point in writing
** any pages with page numbers greater than nTruncate into the WAL file.
** They will never be read by any client. So remove them from the pDirty
** list here. */
PgHdr* p;
PgHdr** ppNext = &pList;
for (p = pList; (*ppNext = p); p = p->pDirty)
{
if (p->pgno <= nTruncate) ppNext = &p->pDirty;
}
assert(pList);
}
if (pList->pgno == 1) pager_write_changecounter(pList);
rc = sqlite3WalFrames(pPager.pWal,
pPager.pageSize, pList, nTruncate, isCommit, syncFlags
);
if (rc == SQLITE.OK && pPager.pBackup)
{
PgHdr* p;
for (p = pList; p; p = p->pDirty)
{
sqlite3BackupUpdate(pPager.pBackup, p->pgno, (u8*)p->pData);
}
}
#if SQLITE_CHECK_PAGES
pList = sqlite3PcacheDirtyList(pPager.pPCache);
for(p=pList; p; p=p->pDirty){
pager_set_pagehash(p);
}
#endif
return rc;
}
internal static void checkList(IntegrityCk pCheck, int isFreeList, int iPage, int N, string zContext)
{
int i;
int expected = N;
int iFirst = iPage;
while (N-- > 0 && pCheck.mxErr != 0)
{
var pOvflPage = new PgHdr();
if (iPage < 1)
{
checkAppendMsg(pCheck, zContext, "%d of %d pages missing from overflow list starting at %d", N + 1, expected, iFirst);
break;
}
if (checkRef(pCheck, (uint)iPage, zContext) != 0)
{
break;
}
byte[] pOvflData;
if (Pager.sqlite3PagerGet(pCheck.pPager, (Pgno)iPage, ref pOvflPage) != 0)
{
checkAppendMsg(pCheck, zContext, "failed to get page %d", iPage);
break;
}
pOvflData = Pager.sqlite3PagerGetData(pOvflPage);
if (isFreeList != 0)
{
int n = (int)ConvertEx.sqlite3Get4byte(pOvflData, 4);
#if !SQLITE_OMIT_AUTOVACUUM
if (pCheck.pBt.autoVacuum)
{
checkPtrmap(pCheck, (uint)iPage, PTRMAP_FREEPAGE, 0, zContext);
}
#endif
if (n > (int)pCheck.pBt.usableSize / 4 - 2)
{
checkAppendMsg(pCheck, zContext, "freelist leaf count too big on page %d", iPage);
N--;
}
else
{
for (i = 0; i < n; i++)
{
Pgno iFreePage = ConvertEx.sqlite3Get4byte(pOvflData, 8 + i * 4);
#if !SQLITE_OMIT_AUTOVACUUM
if (pCheck.pBt.autoVacuum)
{
checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0, zContext);
}
#endif
checkRef(pCheck, iFreePage, zContext);
}
N -= n;
}
}
#if !SQLITE_OMIT_AUTOVACUUM
else
{
/* If this database supports auto-vacuum and iPage is not the last
** page in this overflow list, check that the pointer-map entry for
** the following page matches iPage.
*/
if (pCheck.pBt.autoVacuum && N > 0)
{
i = (int)ConvertEx.sqlite3Get4byte(pOvflData);
checkPtrmap(pCheck, (uint)i, PTRMAP_OVERFLOW2, (uint)iPage, zContext);
}
}
#endif
iPage = (int)ConvertEx.sqlite3Get4byte(pOvflData);
Pager.sqlite3PagerUnref(pOvflPage);
}
}
internal static void assertTruncateConstraintCb(PgHdr pPg)
{
Debug.Assert((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0); Debug.Assert(!subjRequiresPage(pPg) || pPg.ID <= pPg.Pager.dbSize);
}
private static RC readDbPage(PgHdr pPg)
{
var pPager = pPg.Pager; // Pager object associated with page pPg
var pgno = pPg.ID; // Page number to read
var rc = RC.OK; // Return code
var isInWal = 0; // True if page is in log file
var pgsz = pPager.pageSize; // Number of bytes to read
Debug.Assert(pPager.eState >= PAGER.READER &&
#if SQLITE_OMIT_MEMORYDB
0 == MEMDB
#else
0 == pPager.memDb
#endif
);
Debug.Assert(pPager.fd.IsOpen);
if (Check.NEVER(!pPager.fd.IsOpen))
{
Debug.Assert(pPager.tempFile);
Array.Clear(pPg.Data, 0, pPager.pageSize);
return RC.OK;
}
if (pPager.pagerUseWal())
// Try to pull the page from the write-ahead log.
rc = pPager.pWal.Read(pgno, ref isInWal, pgsz, pPg.Data);
if (rc == RC.OK && 0 == isInWal)
{
long iOffset = (pgno - 1) * (long)pPager.pageSize;
rc = pPager.fd.Read(pPg.Data, pgsz, iOffset);
if (rc == RC.IOERR_SHORT_READ)
rc = RC.OK;
}
if (pgno == 1)
{
if (rc != 0)
// If the read is unsuccessful, set the dbFileVers[] to something that will never be a valid file version. dbFileVers[] is a copy
// of bytes 24..39 of the database. Bytes 28..31 should always be zero or the size of the database in page. Bytes 32..35 and 35..39
// should be page numbers which are never 0xffffffff. So filling pPager.dbFileVers[] with all 0xff bytes should suffice.
//
// For an encrypted database, the situation is more complex: bytes 24..39 of the database are white noise. But the probability of
// white noising equaling 16 bytes of 0xff is vanishingly small so we should still be ok.
for (int i = 0; i < pPager.dbFileVers.Length; pPager.dbFileVers[i++] = 0xff) ; // memset(pPager.dbFileVers, 0xff, sizeof(pPager.dbFileVers));
else
Buffer.BlockCopy(pPg.Data, 24, pPager.dbFileVers, 0, pPager.dbFileVers.Length);
}
if (CODEC1(pPager, pPg.Data, pgno, codec_ctx.DECRYPT))
rc = RC.NOMEM;
SysEx.IOTRACE("PGIN {0:x} {1}", pPager.GetHashCode(), pgno);
PAGERTRACE("FETCH {0} page {1}% hash({2,08:x})", PAGERID(pPager), pgno, pager_pagehash(pPg));
return rc;
}
// was:fetchPayload
private RC AccessPayload(uint offset, uint size, byte[] b, bool writeOperation)
{
var page = Pages[PageID]; // Btree page of current entry
Debug.Assert(page != null);
Debug.Assert(State == CursorState.VALID);
Debug.Assert(PagesIndexs[PageID] < page.Cells);
Debug.Assert(HoldsMutex());
GetCellInfo();
var payload = Info.Cells;
var nKey = (uint)(page.HasIntKey ? 0 : (int)Info.nKey);
var shared = Shared; // Btree this cursor belongs to
if (Check.NEVER(offset + size > nKey + Info.nData) || Info.nLocal > shared.UsableSize)
{
// Trying to read or write past the end of the data is an error
return(SysEx.SQLITE_CORRUPT_BKPT());
}
// Check if data must be read/written to/from the btree page itself.
var rc = RC.OK;
uint bOffset = 0;
if (offset < Info.nLocal)
{
var a = (int)size;
if (a + offset > Info.nLocal)
{
a = (int)(Info.nLocal - offset);
}
rc = CopyPayload(page.DbPage, payload, (uint)(offset + Info.CellID + Info.nHeader), b, bOffset, (uint)a, writeOperation);
offset = 0;
bOffset += (uint)a;
size -= (uint)a;
}
else
{
offset -= Info.nLocal;
}
var iIdx = 0;
if (rc == RC.OK && size > 0)
{
var ovflSize = (uint)(shared.UsableSize - 4); // Bytes content per ovfl page
var nextPage = (Pgno)ConvertEx.Get4(payload, Info.nLocal + Info.CellID + Info.nHeader);
#if !SQLITE_OMIT_INCRBLOB
// If the isIncrblobHandle flag is set and the BtCursor.aOverflow[] has not been allocated, allocate it now. The array is sized at
// one entry for each overflow page in the overflow chain. The page number of the first overflow page is stored in aOverflow[0],
// etc. A value of 0 in the aOverflow[] array means "not yet known" (the cache is lazily populated).
if (IsIncrblob && OverflowIDs == null)
{
var nOvfl = (Info.nPayload - Info.nLocal + ovflSize - 1) / ovflSize;
OverflowIDs = new Pgno[nOvfl];
}
// If the overflow page-list cache has been allocated and the entry for the first required overflow page is valid, skip directly to it.
if (OverflowIDs != null && OverflowIDs[offset / ovflSize] != 0)
{
iIdx = (int)(offset / ovflSize);
nextPage = OverflowIDs[iIdx];
offset = (offset % ovflSize);
}
#endif
for (; rc == RC.OK && size > 0 && nextPage != 0; iIdx++)
{
#if !SQLITE_OMIT_INCRBLOB
// If required, populate the overflow page-list cache.
if (OverflowIDs != null)
{
Debug.Assert(OverflowIDs[iIdx] == 0 || OverflowIDs[iIdx] == nextPage);
OverflowIDs[iIdx] = nextPage;
}
#endif
MemPage MemPageDummy = null;
if (offset >= ovflSize)
{
// The only reason to read this page is to obtain the page number for the next page in the overflow chain. The page
// data is not required. So first try to lookup the overflow page-list cache, if any, then fall back to the getOverflowPage() function.
#if !SQLITE_OMIT_INCRBLOB
if (OverflowIDs != null && OverflowIDs[iIdx + 1] != 0)
{
nextPage = OverflowIDs[iIdx + 1];
}
else
#endif
rc = shared.getOverflowPage(nextPage, out MemPageDummy, out nextPage);
offset -= ovflSize;
}
else
{
// Need to read this page properly. It contains some of the range of data that is being read (eOp==null) or written (eOp!=null).
var pDbPage = new PgHdr();
var a = (int)size;
rc = shared.Pager.Get(nextPage, ref pDbPage);
if (rc == RC.OK)
{
payload = Pager.sqlite3PagerGetData(pDbPage);
nextPage = ConvertEx.Get4(payload);
if (a + offset > ovflSize)
{
a = (int)(ovflSize - offset);
}
rc = CopyPayload(pDbPage, payload, offset + 4, b, bOffset, (uint)a, writeOperation);
Pager.Unref(pDbPage);
offset = 0;
size -= (uint)a;
bOffset += (uint)a;
}
}
}
}
if (rc == RC.OK && size > 0)
{
return(SysEx.SQLITE_CORRUPT_BKPT());
}
return(rc);
}
private static RC pager_write(PgHdr pPg)
{
var pData = pPg.Data;
var pPager = pPg.Pager;
var rc = RC.OK;
// This routine is not called unless a write-transaction has already been started. The journal file may or may not be open at this point.
// It is never called in the ERROR state.
Debug.Assert(pPager.eState == PAGER.WRITER_LOCKED || pPager.eState == PAGER.WRITER_CACHEMOD || pPager.eState == PAGER.WRITER_DBMOD);
Debug.Assert(pPager.assert_pager_state());
// If an error has been previously detected, report the same error again. This should not happen, but the check provides robustness.
if (Check.NEVER(pPager.errCode) != RC.OK)
{
return(pPager.errCode);
}
// Higher-level routines never call this function if database is not writable. But check anyway, just for robustness.
if (Check.NEVER(pPager.readOnly))
{
return(RC.PERM);
}
#if SQLITE_CHECK_PAGES
CHECK_PAGE(pPg);
#endif
// The journal file needs to be opened. Higher level routines have already obtained the necessary locks to begin the write-transaction, but the
// rollback journal might not yet be open. Open it now if this is the case.
//
// This is done before calling sqlite3PcacheMakeDirty() on the page. Otherwise, if it were done after calling sqlite3PcacheMakeDirty(), then
// an error might occur and the pager would end up in WRITER_LOCKED state with pages marked as dirty in the cache.
if (pPager.eState == PAGER.WRITER_LOCKED)
{
rc = pPager.pager_open_journal();
if (rc != RC.OK)
{
return(rc);
}
}
Debug.Assert(pPager.eState >= PAGER.WRITER_CACHEMOD);
Debug.Assert(pPager.assert_pager_state());
// Mark the page as dirty. If the page has already been written to the journal then we can return right away.
PCache.MakePageDirty(pPg);
if (pageInJournal(pPg) && !subjRequiresPage(pPg))
{
Debug.Assert(!pPager.pagerUseWal());
}
else
{
// 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 (!pageInJournal(pPg) && !pPager.pagerUseWal())
{
Debug.Assert(!pPager.pagerUseWal());
if (pPg.ID <= pPager.dbOrigSize && pPager.jfd.IsOpen)
{
var iOff = pPager.journalOff;
// We should never write to the journal file the page that contains the database locks. The following Debug.Assert verifies that we do not.
Debug.Assert(pPg.ID != ((VirtualFile.PENDING_BYTE / (pPager.pageSize)) + 1));
Debug.Assert(pPager.journalHdr <= pPager.journalOff);
byte[] pData2 = null;
if (CODEC2(pPager, pData, pPg.ID, codec_ctx.ENCRYPT_READ_CTX, ref pData2))
{
return(RC.NOMEM);
}
var cksum = pPager.pager_cksum(pData2);
// Even if an IO or diskfull error occurred while journalling the page in the block above, set the need-sync flag for the page.
// Otherwise, when the transaction is rolled back, the logic in playback_one_page() will think that the page needs to be restored
// in the database file. And if an IO error occurs while doing so, then corruption may follow.
pPg.Flags |= PgHdr.PGHDR.NEED_SYNC;
rc = pPager.jfd.WriteByte(iOff, pPg.ID);
if (rc != RC.OK)
{
return(rc);
}
rc = pPager.jfd.Write(pData2, pPager.pageSize, iOff + 4);
if (rc != RC.OK)
{
return(rc);
}
rc = pPager.jfd.WriteByte(iOff + pPager.pageSize + 4, cksum);
if (rc != RC.OK)
{
return(rc);
}
SysEx.IOTRACE("JOUT {0:x} {1} {2,11} {3}", pPager.GetHashCode(), pPg.ID, pPager.journalOff, pPager.pageSize);
PAGERTRACE("JOURNAL {0} page {1} needSync={2} hash({3,08:x})", PAGERID(pPager), pPg.ID, (pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0 ? 1 : 0, pager_pagehash(pPg));
pPager.journalOff += 8 + pPager.pageSize;
pPager.nRec++;
Debug.Assert(pPager.pInJournal != null);
rc = pPager.pInJournal.Set(pPg.ID);
Debug.Assert(rc == RC.OK || rc == RC.NOMEM);
rc |= pPager.addToSavepointBitvecs(pPg.ID);
if (rc != RC.OK)
{
Debug.Assert(rc == RC.NOMEM);
return(rc);
}
}
else
{
if (pPager.eState != PAGER.WRITER_DBMOD)
{
pPg.Flags |= PgHdr.PGHDR.NEED_SYNC;
}
PAGERTRACE("APPEND {0} page {1} needSync={2}", PAGERID(pPager), pPg.ID, (pPg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0 ? 1 : 0);
}
}
// 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 (subjRequiresPage(pPg))
{
rc = subjournalPage(pPg);
}
}
// Update the database size and return.
if (pPager.dbSize < pPg.ID)
{
pPager.dbSize = pPg.ID;
}
return(rc);
}
/*
** This function is a wrapper around sqlite3WalFrames(). As well as logging
** the contents of the list of pages headed by pList (connected by pDirty),
** this function notifies any active backup processes that the pages have
** changed.
**
** The list of pages passed into this routine is always sorted by page number.
** Hence, if page 1 appears anywhere on the list, it will be the first page.
*/
static int pagerWalFrames(Pager pPager, PgHdr pList, Pgno nTruncate, int isCommit, int syncFlags)
{
int rc; /* Return code */
#if DEBUG || (SQLITE_CHECK_PAGES)
PgHdr p; /* For looping over pages */
#endif
Debug.Assert(pPager.pWal);
#if SQLITE_DEBUG
/* Verify that the page list is in accending order */
for (p = pList; p && p->pDirty; p = p->pDirty)
{
assert(p->pgno < p->pDirty->pgno);
}
#endif
if (isCommit)
{
/* If a WAL transaction is being committed, there is no point in writing
** any pages with page numbers greater than nTruncate into the WAL file.
** They will never be read by any client. So remove them from the pDirty
** list here. */
PgHdr * p;
PgHdr **ppNext = &pList;
for (p = pList; (*ppNext = p); p = p->pDirty)
{
if (p->pgno <= nTruncate)
{
ppNext = &p->pDirty;
}
}
assert(pList);
}
if (pList->pgno == 1)
{
pager_write_changecounter(pList);
}
rc = sqlite3WalFrames(pPager.pWal,
pPager.pageSize, pList, nTruncate, isCommit, syncFlags
);
if (rc == SQLITE.OK && pPager.pBackup)
{
PgHdr *p;
for (p = pList; p; p = p->pDirty)
{
sqlite3BackupUpdate(pPager.pBackup, p->pgno, (u8 *)p->pData);
}
}
#if SQLITE_CHECK_PAGES
pList = sqlite3PcacheDirtyList(pPager.pPCache);
for (p = pList; p; p = p->pDirty)
{
pager_set_pagehash(p);
}
#endif
return(rc);
}
// was:fetchPayload
private RC AccessPayload(uint offset, uint size, byte[] b, bool writeOperation)
{
var page = Pages[PageID]; // Btree page of current entry
Debug.Assert(page != null);
Debug.Assert(State == CursorState.VALID);
Debug.Assert(PagesIndexs[PageID] < page.Cells);
Debug.Assert(HoldsMutex());
GetCellInfo();
var payload = Info.Cells;
var nKey = (uint)(page.HasIntKey ? 0 : (int)Info.nKey);
var shared = Shared; // Btree this cursor belongs to
if (Check.NEVER(offset + size > nKey + Info.nData) || Info.nLocal > shared.UsableSize)
// Trying to read or write past the end of the data is an error
return SysEx.SQLITE_CORRUPT_BKPT();
// Check if data must be read/written to/from the btree page itself.
var rc = RC.OK;
uint bOffset = 0;
if (offset < Info.nLocal)
{
var a = (int)size;
if (a + offset > Info.nLocal)
a = (int)(Info.nLocal - offset);
rc = CopyPayload(page.DbPage, payload, (uint)(offset + Info.CellID + Info.nHeader), b, bOffset, (uint)a, writeOperation);
offset = 0;
bOffset += (uint)a;
size -= (uint)a;
}
else
offset -= Info.nLocal;
var iIdx = 0;
if (rc == RC.OK && size > 0)
{
var ovflSize = (uint)(shared.UsableSize - 4); // Bytes content per ovfl page
var nextPage = (Pgno)ConvertEx.Get4(payload, Info.nLocal + Info.CellID + Info.nHeader);
#if !SQLITE_OMIT_INCRBLOB
// If the isIncrblobHandle flag is set and the BtCursor.aOverflow[] has not been allocated, allocate it now. The array is sized at
// one entry for each overflow page in the overflow chain. The page number of the first overflow page is stored in aOverflow[0],
// etc. A value of 0 in the aOverflow[] array means "not yet known" (the cache is lazily populated).
if (IsIncrblob && OverflowIDs == null)
{
var nOvfl = (Info.nPayload - Info.nLocal + ovflSize - 1) / ovflSize;
OverflowIDs = new Pgno[nOvfl];
}
// If the overflow page-list cache has been allocated and the entry for the first required overflow page is valid, skip directly to it.
if (OverflowIDs != null && OverflowIDs[offset / ovflSize] != 0)
{
iIdx = (int)(offset / ovflSize);
nextPage = OverflowIDs[iIdx];
offset = (offset % ovflSize);
}
#endif
for (; rc == RC.OK && size > 0 && nextPage != 0; iIdx++)
{
#if !SQLITE_OMIT_INCRBLOB
// If required, populate the overflow page-list cache.
if (OverflowIDs != null)
{
Debug.Assert(OverflowIDs[iIdx] == 0 || OverflowIDs[iIdx] == nextPage);
OverflowIDs[iIdx] = nextPage;
}
#endif
MemPage MemPageDummy = null;
if (offset >= ovflSize)
{
// The only reason to read this page is to obtain the page number for the next page in the overflow chain. The page
// data is not required. So first try to lookup the overflow page-list cache, if any, then fall back to the getOverflowPage() function.
#if !SQLITE_OMIT_INCRBLOB
if (OverflowIDs != null && OverflowIDs[iIdx + 1] != 0)
nextPage = OverflowIDs[iIdx + 1];
else
#endif
rc = shared.getOverflowPage(nextPage, out MemPageDummy, out nextPage);
offset -= ovflSize;
}
else
{
// Need to read this page properly. It contains some of the range of data that is being read (eOp==null) or written (eOp!=null).
var pDbPage = new PgHdr();
var a = (int)size;
rc = shared.Pager.Get(nextPage, ref pDbPage);
if (rc == RC.OK)
{
payload = Pager.sqlite3PagerGetData(pDbPage);
nextPage = ConvertEx.Get4(payload);
if (a + offset > ovflSize)
a = (int)(ovflSize - offset);
rc = CopyPayload(pDbPage, payload, offset + 4, b, bOffset, (uint)a, writeOperation);
Pager.Unref(pDbPage);
offset = 0;
size -= (uint)a;
bOffset += (uint)a;
}
}
}
}
if (rc == RC.OK && size > 0)
return SysEx.SQLITE_CORRUPT_BKPT();
return rc;
}
public RC Get(Pgno pgno, ref DbPage ppPage, byte noContent)
{
Debug.Assert(eState >= PAGER.READER);
Debug.Assert(assert_pager_state());
if (pgno == 0)
{
return(SysEx.SQLITE_CORRUPT_BKPT());
}
// If the pager is in the error state, return an error immediately. Otherwise, request the page from the PCache layer.
var rc = (errCode != RC.OK ? errCode : pPCache.FetchPage(pgno, 1, ref ppPage));
PgHdr pPg = null;
if (rc != RC.OK)
{
// Either the call to sqlite3PcacheFetch() returned an error or the pager was already in the error-state when this function was called.
// Set pPg to 0 and jump to the exception handler. */
pPg = null;
goto pager_get_err;
}
Debug.Assert((ppPage).ID == pgno);
Debug.Assert((ppPage).Pager == this || (ppPage).Pager == null);
if ((ppPage).Pager != null && 0 == noContent)
{
// In this case the pcache already contains an initialized copy of the page. Return without further ado.
Debug.Assert(pgno <= PAGER_MAX_PGNO && pgno != PAGER_MJ_PGNO(this));
return(RC.OK);
}
else
{
// The pager cache has created a new page. Its content needs to be initialized.
pPg = ppPage;
pPg.Pager = this;
pPg.Extra = _memPageBuilder;
// The maximum page number is 2^31. Return SQLITE_CORRUPT if a page number greater than this, or the unused locking-page, is requested.
if (pgno > PAGER_MAX_PGNO || pgno == PAGER_MJ_PGNO(this))
{
rc = SysEx.SQLITE_CORRUPT_BKPT();
goto pager_get_err;
}
if (
#if SQLITE_OMIT_MEMORYDB
1 == MEMDB
#else
memDb != 0
#endif
|| dbSize < pgno || noContent != 0 || !fd.IsOpen)
{
if (pgno > mxPgno)
{
rc = RC.FULL;
goto pager_get_err;
}
if (noContent != 0)
{
// Failure to set the bits in the InJournal bit-vectors is benign. It merely means that we might do some extra work to journal a
// page that does not need to be journaled. Nevertheless, be sure to test the case where a malloc error occurs while trying to set
// a bit in a bit vector.
MallocEx.sqlite3BeginBenignMalloc();
if (pgno <= dbOrigSize)
{
pInJournal.Set(pgno);
}
addToSavepointBitvecs(pgno);
MallocEx.sqlite3EndBenignMalloc();
}
Array.Clear(pPg.Data, 0, pageSize);
SysEx.IOTRACE("ZERO {0:x} {1}\n", this.GetHashCode(), pgno);
}
