Ejemplo n.º 1
0
 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;
 }
Ejemplo n.º 2
0
 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
 }
Ejemplo n.º 3
0
        public PgHdr pPage1;        // Reference to page 1

        public void ClearState()
        {
            pDirty = null;
            pDirtyTail = null;
            pSynced = null;
            nRef = 0;
        }
Ejemplo n.º 4
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);
     }
 }
Ejemplo n.º 5
0
 // 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);
     }
 }
Ejemplo n.º 6
0
 // 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);
     }
 }
Ejemplo n.º 7
0
 // 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);
     }
 }
Ejemplo n.º 8
0
 // 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);
 }
Ejemplo n.º 9
0
 // 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);
     }
 }
Ejemplo n.º 10
0
 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;
 }
Ejemplo n.º 11
0
 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
 }
Ejemplo n.º 12
0
 // 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);
         }
     }
 }
Ejemplo n.º 13
0
        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
        }
Ejemplo n.º 14
0
        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);
        }
Ejemplo n.º 15
0
        // 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);
        }
Ejemplo n.º 16
0
        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);
        }
Ejemplo n.º 17
0
        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
        }
Ejemplo n.º 18
0
 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;
 }
Ejemplo n.º 19
0
 internal static int sqlite3PcachePageRefcount(PgHdr p)
 {
     return p.Refs;
 }
Ejemplo n.º 20
0
 internal static void assertTruncateConstraintCb(PgHdr pPg)
 {
 }
Ejemplo n.º 21
0
 internal static void pager_set_pagehash(PgHdr X)
 {
 }
Ejemplo n.º 22
0
 internal static void pager_set_pagehash(PgHdr pPage)
 {
     pPage.PageHash = pager_pagehash(pPage);
 }
Ejemplo n.º 23
0
 internal RC pagerWalFrames(PgHdr w, Pgno x, int y, VirtualFile.SYNC z)
 {
     return(RC.OK);
 }
Ejemplo n.º 24
0
 internal static void assertTruncateConstraintCb(PgHdr pPg)
 {
 }
Ejemplo n.º 25
0
 private static bool pageInJournal(PgHdr pPg)
 {
     return pPg.Pager.pInJournal.Get(pPg.ID) != 0;
 }
Ejemplo n.º 26
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;
 }
Ejemplo n.º 27
0
 internal static int sqlite3PcachePageRefcount(PgHdr p)
 {
     return(p.Refs);
 }
Ejemplo n.º 28
0
        // 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);
        }
Ejemplo n.º 29
0
 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;
 }
Ejemplo n.º 30
0
 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;
 }
Ejemplo n.º 31
0
        // 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);
        }
Ejemplo n.º 32
0
 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);
 }
Ejemplo n.º 33
0
 /*
 ** 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;
 }
Ejemplo n.º 34
0
 // was:sqlite3PcacheRef
 internal static void AddPageRef(PgHdr p)
 {
     Debug.Assert(p.Refs > 0); p.Refs++;
 }
Ejemplo n.º 35
0
 internal static uint pager_pagehash(PgHdr pPage)
 {
     return(pager_datahash(pPage.Pager.pageSize, pPage.Data));
 }
Ejemplo n.º 36
0
        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);
        }
Ejemplo n.º 37
0
 internal static uint pager_pagehash(PgHdr X)
 {
     return(0);
 }
Ejemplo n.º 38
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);
        }
Ejemplo n.º 39
0
 internal static void assertTruncateConstraintCb(PgHdr pPg)
 {
     Debug.Assert((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0); Debug.Assert(!subjRequiresPage(pPg) || pPg.ID <= pPg.Pager.dbSize);
 }
Ejemplo n.º 40
0
        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));
        }
Ejemplo n.º 41
0
 // 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);
         }
     }
 }
Ejemplo n.º 42
0
 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;
 }
Ejemplo n.º 43
0
 // 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);
 }
Ejemplo n.º 44
0
 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);
 }
Ejemplo n.º 45
0
 // was:sqlite3PcacheRef
 internal static void AddPageRef(PgHdr p)
 {
     Debug.Assert(p.Refs > 0); p.Refs++;
 }
Ejemplo n.º 46
0
        // 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;
        }
Ejemplo n.º 47
0
 private static bool pageInJournal(PgHdr pPg)
 {
     return(pPg.Pager.pInJournal.Get(pPg.ID));
 }
Ejemplo n.º 48
0
        /*
        ** 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;
        }
Ejemplo n.º 49
0
        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);
            }
        }
Ejemplo n.º 50
0
 internal static void assertTruncateConstraintCb(PgHdr pPg)
 {
     Debug.Assert((pPg.Flags & PgHdr.PGHDR.DIRTY) != 0); Debug.Assert(!subjRequiresPage(pPg) || pPg.ID <= pPg.Pager.dbSize);
 }
Ejemplo n.º 51
0
 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;
 }
Ejemplo n.º 52
0
        // 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);
        }
Ejemplo n.º 53
0
        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);
        }
Ejemplo n.º 54
0
        /*
        ** 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);
        }
Ejemplo n.º 55
0
 // 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;
 }
Ejemplo n.º 56
0
        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);
                }