public static void MakeClean(PgHdr p)
{
if ((p.Flags & PgHdr.PGHDR.DIRTY) != 0)
{
RemoveFromDirtyList(p);
p.Flags &= ~(PgHdr.PGHDR.DIRTY | PgHdr.PGHDR.NEED_SYNC);
if (p.Refs == 0)
Unpin(p);
}
}
public static void MakeDirty(PgHdr p)
{
p.Flags &= ~PgHdr.PGHDR.DONT_WRITE;
Debug.Assert(p.Refs > 0);
if ((p.Flags & PgHdr.PGHDR.DIRTY) == 0)
{
p.Flags |= PgHdr.PGHDR.DIRTY;
AddToDirtyList(p);
}
}
public static void Drop(PgHdr p)
{
Debug.Assert(p.Refs == 1);
if ((p.Flags & PgHdr.PGHDR.DIRTY) != 0)
RemoveFromDirtyList(p);
var cache = p.Cache;
cache.Refs--;
if (p.ID == 1)
cache.Page1 = null;
cache.Cache.Unpin(p.Page, true);
}
public static void Move(PgHdr p, Pid newID)
{
PCache cache = p.Cache;
Debug.Assert(p.Refs > 0);
Debug.Assert(newID > 0);
cache.Cache.Rekey(p.Page, p.ID, newID);
p.ID = newID;
if ((p.Flags & PgHdr.PGHDR.DIRTY) != 0 && (p.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
RemoveFromDirtyList(p);
AddToDirtyList(p);
}
}
public static void Release(PgHdr p)
{
Debug.Assert(p.Refs > 0);
p.Refs--;
if (p.Refs == 0)
{
var cache = p.Cache;
cache.Refs--;
if ((p.Flags & PgHdr.PGHDR.DIRTY) == 0)
{
Unpin(p);
}
else
{
// Move the page to the head of the dirty list.
RemoveFromDirtyList(p);
AddToDirtyList(p);
}
}
}
private static void RemoveFromDirtyList(PgHdr page)
{
var p = page.Cache;
Debug.Assert(page.DirtyNext != null || page == p.DirtyTail);
Debug.Assert(page.DirtyPrev != null || page == p.Dirty);
// Update the PCache1.pSynced variable if necessary.
if (p.Synced == page)
{
var synced = page.DirtyPrev;
while (synced != null && (synced.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
{
synced = synced.DirtyPrev;
}
p.Synced = synced;
}
if (page.DirtyNext != null)
{
page.DirtyNext.DirtyPrev = page.DirtyPrev;
}
else
{
Debug.Assert(page == p.DirtyTail);
p.DirtyTail = page.DirtyPrev;
}
if (page.DirtyPrev != null)
{
page.DirtyPrev.DirtyNext = page.DirtyNext;
}
else
{
Debug.Assert(page == p.Dirty);
p.Dirty = page.DirtyNext;
}
page.DirtyNext = null;
page.DirtyPrev = null;
#if EXPENSIVE_ASSERT
Debug.Assert(CheckSynced(p));
#endif
}
private static PgHdr SortDirtyList(PgHdr @in)
{
var a = new PgHdr[N_SORT_BUCKET];
PgHdr p;
int i;
while (@in != null)
{
p = @in;
@in = p.Dirty;
p.Dirty = null;
for (i = 0; C._ALWAYS(i < N_SORT_BUCKET - 1); i++)
{
if (a[i] == null)
{
a[i] = p;
break;
}
else
{
p = MergeDirtyList(a[i], p);
a[i] = null;
}
}
if (C._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] = MergeDirtyList(a[i], p);
}
}
p = a[0];
for (i = 1; i < N_SORT_BUCKET; i++)
{
p = MergeDirtyList(p, a[i]);
}
return(p);
}
private static void AddToDirtyList(PgHdr page)
{
var p = page.Cache;
Debug.Assert(page.DirtyNext == null && page.DirtyPrev == null && p.Dirty != page);
page.DirtyNext = p.Dirty;
if (page.DirtyNext != null)
{
Debug.Assert(page.DirtyNext.DirtyPrev == null);
page.DirtyNext.DirtyPrev = page;
}
p.Dirty = page;
if (p.DirtyTail == null)
{
p.DirtyTail = page;
}
if (p.Synced == null && (page.Flags & PgHdr.PGHDR.NEED_SYNC) == 0)
{
p.Synced = page;
}
#if EXPENSIVE_ASSERT
Debug.Assert(CheckSynced(p));
#endif
}
private static void Unpin(PgHdr p)
{
var cache = p.Cache;
if (cache.Purgeable)
{
if (p.ID == 1)
cache.Page1 = null;
cache.Cache.Unpin(p.Page, false);
}
}
private static PgHdr SortDirtyList(PgHdr @in)
{
var a = new PgHdr[N_SORT_BUCKET];
PgHdr p;
int i;
while (@in != null)
{
p = @in;
@in = p.Dirty;
p.Dirty = null;
for (i = 0; SysEx.ALWAYS(i < N_SORT_BUCKET - 1); i++)
{
if (a[i] == null)
{
a[i] = p;
break;
}
else
{
p = MergeDirtyList(a[i], p);
a[i] = null;
}
}
if (SysEx.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] = MergeDirtyList(a[i], p);
}
p = a[0];
for (i = 1; i < N_SORT_BUCKET; i++)
p = MergeDirtyList(p, a[i]);
return p;
}
public static int get_PageRefs(PgHdr p)
{
return p.Refs;
}
private static PgHdr MergeDirtyList(PgHdr a, PgHdr b)
{
var result = new PgHdr();
var tail = result;
while (a != null && b != null)
{
if (a.ID < b.ID)
{
tail.Dirty = a;
tail = a;
a = a.Dirty;
}
else
{
tail.Dirty = b;
tail = b;
b = b.Dirty;
}
}
if (a != null)
tail.Dirty = a;
else if (b != null)
tail.Dirty = b;
else
tail.Dirty = null;
return result.Dirty;
}
private static void RemoveFromDirtyList(PgHdr page)
{
var p = page.Cache;
Debug.Assert(page.DirtyNext != null || page == p.DirtyTail);
Debug.Assert(page.DirtyPrev != null || page == p.Dirty);
// Update the PCache1.pSynced variable if necessary.
if (p.Synced == page)
{
var synced = page.DirtyPrev;
while (synced != null && (synced.Flags & PgHdr.PGHDR.NEED_SYNC) != 0)
synced = synced.DirtyPrev;
p.Synced = synced;
}
if (page.DirtyNext != null)
page.DirtyNext.DirtyPrev = page.DirtyPrev;
else
{
Debug.Assert(page == p.DirtyTail);
p.DirtyTail = page.DirtyPrev;
}
if (page.DirtyPrev != null)
page.DirtyPrev.DirtyNext = page.DirtyNext;
else
{
Debug.Assert(page == p.Dirty);
p.Dirty = page.DirtyNext;
}
page.DirtyNext = null;
page.DirtyPrev = null;
#if EXPENSIVE_ASSERT
Debug.Assert(CheckSynced(p));
#endif
}
//public static implicit operator bool(PgHdr b) { return (b != null); }
public void memset()
{
//Page = null;
Data = null;
Extra = null;
Dirty = null;
Pager = null;
ID = 0;
#if CHECK_PAGES
PageHash = 0;
#endif
Flags = 0;
Refs = 0;
Cache = null;
DirtyNext = null;
DirtyPrev = null;
}
private static void AddToDirtyList(PgHdr page)
{
var p = page.Cache;
Debug.Assert(page.DirtyNext == null && page.DirtyPrev == null && p.Dirty != page);
page.DirtyNext = p.Dirty;
if (page.DirtyNext != null)
{
Debug.Assert(page.DirtyNext.DirtyPrev == null);
page.DirtyNext.DirtyPrev = page;
}
p.Dirty = page;
if (p.DirtyTail == null)
p.DirtyTail = page;
if (p.Synced == null && (page.Flags & PgHdr.PGHDR.NEED_SYNC) == 0)
p.Synced = page;
#if EXPENSIVE_ASSERT
Debug.Assert(CheckSynced(p));
#endif
}
internal RC Frames(int v, PgHdr w, Pid x, int y, int z)
{
return 0;
}
public RC Fetch(Pid id, bool createFlag, out PgHdr pageOut)
{
Debug.Assert(id > 0);
// If the pluggable cache (sqlite3_pcache*) has not been allocated, allocate it now.
if (Cache == null && createFlag)
{
var p = _pcache.Create(SizePage, SizeExtra + 0, Purgeable);
p.Cachesize(get_CacheSize());
Cache = p;
}
ICachePage page = null;
var create = (createFlag ? 1 : 0) * (1 + ((!Purgeable || Dirty == null) ? 1 : 0));
if (Cache != null)
page = Cache.Fetch(id, create > 0);
if (page == null && create == 1)
{
// 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 EXPENSIVE_ASSERT
CheckSynced(this);
#endif
PgHdr pg;
for (pg = Synced; pg != null && (pg.Refs != 0 || (pg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0); pg = pg.DirtyPrev) ;
Synced = pg;
if (pg == null)
for (pg = DirtyTail; pg != null && pg.Refs != 0; pg = pg.DirtyPrev) ;
if (pg != null)
{
#if LOG_CACHE_SPILL
SysEx.Log(RC.FULL, "spill page %d making room for %d - cache used: %d/%d", pg.ID, id, _pcache->Pagecount(Cache), NumberOfCachePages(this));
#endif
var rc = Stress(StressArg, pg);
if (rc != RC.OK && rc != RC.BUSY)
{
pageOut = null;
return rc;
}
}
page = Cache.Fetch(id, true);
}
PgHdr pgHdr = null;
if (page != null)
{
//pgHdr = page.Extra;
if (page.Data == null)
{
//page.Page = page;
page.Data = SysEx.Alloc(SizePage);
//page.Extra = this;
page.Cache = this;
page.ID = id;
}
Debug.Assert(page.Cache == Cache);
Debug.Assert(page.ID == id);
//Debug.Assert(page.Data == page.Buffer);
//Debug.Assert(page.Extra == this);
if (page.Refs == 0)
Refs++;
page.Refs++;
if (id == 1)
Page1 = pgHdr;
}
pageOut = pgHdr;
return (pgHdr == null && create != 0 ? RC.NOMEM : RC.OK);
}
public PgHdr Synced; // Last synced page in dirty page list
#endregion Fields
#region Methods
public void memset()
{
Dirty = DirtyTail = null;
Synced = null;
Refs = 0;
}
static void checkList(IntegrityCk check, bool isFreeList, Pid pageID, int length, string context)
{
int expected = length;
Pid firstID = pageID;
while (length-- > 0 && check.MaxErrors != 0)
{
if (pageID < 1)
{
checkAppendMsg(check, context, "%d of %d pages missing from overflow list starting at %d", length + 1, expected, firstID);
break;
}
if (checkRef(check, pageID, context)) break;
PgHdr ovflPage = new PgHdr();
if (check.Pager.Acquire((Pid)pageID, ref ovflPage, false) != RC.OK)
{
checkAppendMsg(check, context, "failed to get page %d", pageID);
break;
}
byte[] ovflData = Pager.GetData(ovflPage);
if (isFreeList)
{
int n = (int)ConvertEx.Get4(ovflData, 4);
#if !OMIT_AUTOVACUUM
if (check.Bt.AutoVacuum)
checkPtrmap(check, (uint)pageID, PTRMAP.FREEPAGE, 0, context);
#endif
if (n > (int)check.Bt.UsableSize / 4 - 2)
{
checkAppendMsg(check, context, "freelist leaf count too big on page %d", pageID);
length--;
}
else
{
for (int i = 0; i < n; i++)
{
Pid freePageID = ConvertEx.Get4(ovflData, 8 + i * 4);
#if !OMIT_AUTOVACUUM
if (check.Bt.AutoVacuum)
checkPtrmap(check, freePageID, PTRMAP.FREEPAGE, 0, context);
#endif
checkRef(check, freePageID, context);
}
length -= n;
}
}
#if !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 (check.Bt.AutoVacuum && length > 0)
{
int i = (int)ConvertEx.Get4(ovflData);
checkPtrmap(check, (uint)i, PTRMAP.OVERFLOW2, (uint)pageID, context);
}
}
#endif
pageID = (Pid)ConvertEx.Get4(ovflData);
Pager.Unref(ovflPage);
}
}
public PgHdr Page1; // Reference to page 1
public void memset()
{
Dirty = DirtyTail = null;
Synced = null;
Refs = 0;
}
public static void PageFree(ref PgHdr p)
{
PCache1.Free(ref p);
}
public static int get_PageRefs(PgHdr p)
{
return(p.Refs);
}
public RC Fetch(Pid id, bool createFlag, out PgHdr pageOut)
{
Debug.Assert(id > 0);
// If the pluggable cache (sqlite3_pcache*) has not been allocated, allocate it now.
if (Cache == null && createFlag)
{
var p = _pcache.Create(SizePage, SizeExtra + 0, Purgeable);
p.Cachesize(get_CacheSize());
Cache = p;
}
ICachePage page = null;
var create = (createFlag ? 1 : 0) * (1 + ((!Purgeable || Dirty == null) ? 1 : 0));
if (Cache != null)
{
page = Cache.Fetch(id, create > 0);
}
if (page == null && create == 1)
{
// 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 EXPENSIVE_ASSERT
CheckSynced(this);
#endif
PgHdr pg;
for (pg = Synced; pg != null && (pg.Refs != 0 || (pg.Flags & PgHdr.PGHDR.NEED_SYNC) != 0); pg = pg.DirtyPrev)
{
;
}
Synced = pg;
if (pg == null)
{
for (pg = DirtyTail; pg != null && pg.Refs != 0; pg = pg.DirtyPrev)
{
;
}
}
if (pg != null)
{
#if LOG_CACHE_SPILL
SysEx.Log(RC.FULL, "spill page %d making room for %d - cache used: %d/%d", pg.ID, id, _pcache->Pagecount(Cache), NumberOfCachePages(this));
#endif
var rc = Stress(StressArg, pg);
if (rc != RC.OK && rc != RC.BUSY)
{
pageOut = null;
return(rc);
}
}
page = Cache.Fetch(id, true);
}
PgHdr pgHdr = null;
if (page != null)
{
//pgHdr = page.Extra;
if (page.Data == null)
{
//page.Page = page;
page.Data = C._alloc(SizePage);
//page.Extra = this;
page.Cache = this;
page.ID = id;
}
Debug.Assert(page.Cache == Cache);
Debug.Assert(page.ID == id);
//Debug.Assert(page.Data == page.Buffer);
//Debug.Assert(page.Extra == this);
if (page.Refs == 0)
{
Refs++;
}
page.Refs++;
if (id == 1)
{
Page1 = pgHdr;
}
}
pageOut = pgHdr;
return(pgHdr == null && create != 0 ? RC.NOMEM : RC.OK);
}
public static void Ref(PgHdr p)
{
Debug.Assert(p.Refs > 0);
p.Refs++;
}
public static void PageFree(ref PgHdr p)
{
PCache1.Free(ref p);
}
public static void Ref(PgHdr p)
{
Debug.Assert(p.Refs > 0);
p.Refs++;
}
static RC accessPayload(BtCursor cur, uint offset, uint amount, byte[] buf, int op)
{
MemPage page = cur.Pages[cur.ID]; // Btree page of current entry
Debug.Assert(page != null);
Debug.Assert(cur.State == CURSOR.VALID);
Debug.Assert(cur.Idxs[cur.ID] < page.Cells);
Debug.Assert(cursorHoldsMutex(cur));
getCellInfo(cur);
var payload = cur.Info.Cell; //cur.Info.Cell + cur.Info.Header;
var key = (uint)(page.IntKey ? 0 : (int)cur.Info.Key);
BtShared bt = cur.Bt; // Btree this cursor belongs to
if (C._NEVER(offset + amount > key + cur.Info.Data) || cur.Info.Local > bt.UsableSize)
// Trying to read or write past the end of the data is an error
return SysEx.CORRUPT_BKPT();
// Check if data must be read/written to/from the btree page itself.
var idx = 0U;
var rc = RC.OK;
var buf_ = 0U;
if (offset < cur.Info.Local)
{
int a = (int)amount;
if (a + offset > cur.Info.Local)
a = (int)(cur.Info.Local - offset);
rc = copyPayload(payload, (uint)(offset + cur.Info.Cell_ + cur.Info.Header), buf, buf_, (uint)a, op, page.DBPage);
offset = 0;
buf_ += (uint)a;
amount -= (uint)a;
}
else
offset -= cur.Info.Local;
if (rc == RC.OK && amount > 0)
{
var ovflSize = (uint)(bt.UsableSize - 4); // Bytes content per ovfl page
Pid nextPage = ConvertEx.Get4(payload, cur.Info.Local + cur.Info.Cell_ + cur.Info.Header);
#if !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 (cur.IsIncrblobHandle && cur.Overflows == null)
{
uint ovfl = (cur.Info.Payload - cur.Info.Local + ovflSize - 1) / ovflSize;
cur.Overflows = new Pid[ovfl];
// nOvfl is always positive. If it were zero, fetchPayload would have been used instead of this routine. */
if (C._ALWAYS(ovfl != 0) && cur.Overflows == null)
rc = RC.NOMEM;
}
// 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 (cur.Overflows != null && cur.Overflows[offset / ovflSize] != 0)
{
idx = (offset / ovflSize);
nextPage = cur.Overflows[idx];
offset = (offset % ovflSize);
}
#endif
for (; rc == RC.OK && amount > 0 && nextPage != 0; idx++)
{
#if !OMIT_INCRBLOB
// If required, populate the overflow page-list cache.
if (cur.Overflows != null)
{
Debug.Assert(cur.Overflows[idx] == 0 || cur.Overflows[idx] == nextPage);
cur.Overflows[idx] = nextPage;
}
#endif
MemPage dummy = 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 !OMIT_INCRBLOB
if (cur.Overflows == null && cur.Overflows[idx + 1] != 0)
nextPage = cur.Overflows[idx + 1];
else
#endif
rc = getOverflowPage(bt, nextPage, out dummy, out nextPage);
offset -= ovflSize;
}
else
{
// Need to read this page properly. It contains some of the range of data that is being read (eOp==0) or written (eOp!=0).
int a = (int)amount;
if (a + offset > ovflSize)
a = (int)(ovflSize - offset);
#if DIRECT_OVERFLOW_READ
// If all the following are true:
//
// 1) this is a read operation, and
// 2) data is required from the start of this overflow page, and
// 3) the database is file-backed, and
// 4) there is no open write-transaction, and
// 5) the database is not a WAL database,
//
// then data can be read directly from the database file into the output buffer, bypassing the page-cache altogether. This speeds
// up loading large records that span many overflow pages.
VFile fd;
if (op == 0 && // (1)
offset == 0 && // (2)
bt.InTransaction == TRANS.READ && // (4)
(fd = bt.Pager.File())->Methods && // (3)
bt->Page1->Data[19] == 0x01) // (5)
{
var save = new byte[4];
var writeOffset = bufOffset - 4;
Buffer.BlockCopy(buf, writeOffset, save, 0, 4);
rc = fd.Read(buf, a + 4, writeOffset + (long)bt.PageSize * (nextPage - 1));
nextPage = ConvertEx.Get4(buf, writeOffset);
Buffer.BlockCopy(save, 0, buf, writeOffset, 4);
}
else
#endif
{
var dbPage = new PgHdr();
rc = bt.Pager.Acquire(nextPage, ref dbPage, false);
if (rc == RC.OK)
{
payload = Pager.GetData(dbPage);
nextPage = ConvertEx.Get4(payload);
rc = copyPayload(payload, offset + 4, buf, buf_, (uint)a, op, dbPage);
Pager.Unref(dbPage);
offset = 0;
}
}
amount -= (uint)a;
buf_ += (uint)a;
}
}
}
if (rc == RC.OK && amount > 0)
return SysEx.CORRUPT_BKPT();
return rc;
}
public static void Release(PgHdr p)
{
Debug.Assert(p.Refs > 0);
p.Refs--;
if (p.Refs == 0)
{
var cache = p.Cache;
cache.Refs--;
if ((p.Flags & PgHdr.PGHDR.DIRTY) == 0)
Unpin(p);
else
{
// Move the page to the head of the dirty list.
RemoveFromDirtyList(p);
AddToDirtyList(p);
}
}
}
public RC Step(int pages)
{
MutexEx.Enter(SrcCtx.Mutex);
Src.Enter();
if (DestCtx != null)
MutexEx.Enter(DestCtx.Mutex);
RC rc = RC_;
if (!IsFatalError(rc))
{
Pager srcPager = Src.get_Pager(); // Source pager
Pager destPager = Dest.get_Pager(); // Dest pager
Pid srcPage = 0; // Size of source db in pages
bool closeTrans = false; // True if src db requires unlocking
// If the source pager is currently in a write-transaction, return SQLITE_BUSY immediately.
rc = (DestCtx != null && Src.Bt.InTransaction == TRANS.WRITE ? RC.BUSY : RC.OK);
// Lock the destination database, if it is not locked already.
if (rc == RC.OK && !DestLocked && (rc = Dest.BeginTrans(2)) == RC.OK)
{
DestLocked = true;
Dest.GetMeta(Btree.META.SCHEMA_VERSION, ref DestSchema);
}
// If there is no open read-transaction on the source database, open one now. If a transaction is opened here, then it will be closed
// before this function exits.
if (rc == RC.OK && !Src.IsInReadTrans())
{
rc = Src.BeginTrans(0);
closeTrans = true;
}
// Do not allow backup if the destination database is in WAL mode and the page sizes are different between source and destination
int pgszSrc = Src.GetPageSize(); // Source page size
int pgszDest = Dest.GetPageSize(); // Destination page size
IPager.JOURNALMODE destMode = Dest.get_Pager().GetJournalMode(); // Destination journal mode
if (rc == RC.OK && destMode == IPager.JOURNALMODE.WAL && pgszSrc != pgszDest)
rc = RC.READONLY;
// Now that there is a read-lock on the source database, query the source pager for the number of pages in the database.
srcPage = Src.LastPage();
Debug.Assert(srcPage >= 0);
for (int ii = 0; (pages < 0 || ii < pages) && NextId <= (Pid)srcPage && rc == 0; ii++)
{
Pid srcPg = NextId; // Source page number
if (srcPg != Btree.PENDING_BYTE_PAGE(Src.Bt))
{
IPage srcPgAsObj = null; // Source page object
rc = srcPager.Acquire(srcPg, ref srcPgAsObj, false);
if (rc == RC.OK)
{
rc = BackupOnePage(p, srcPg, Pager.GetData(srcPgAsObj), false);
Pager.Unref(srcPgAsObj);
}
}
NextId++;
}
if (rc == RC.OK)
{
Pagecount = srcPage;
Remaining = (srcPage + 1 - NextId);
if (NextId > srcPage)
rc = RC.DONE;
else if (!IsAttached)
AttachBackupObject(p);
}
// Update the schema version field in the destination database. This is to make sure that the schema-version really does change in
// the case where the source and destination databases have the same schema version.
if (rc == RC.DONE)
{
if (srcPage == null)
{
rc = Dest.NewDb();
srcPage = 1;
}
if (rc == RC.OK || rc == RC.DONE)
rc = Dest.UpdateMeta(Btree.META.SCHEMA_VERSION, DestSchema + 1);
if (rc == RC.OK)
{
if (DestCtx != null)
Main.ResetAllSchemasOfConnection(DestCtx);
if (destMode == IPager.JOURNALMODE.WAL)
rc = Dest.SetVersion(2);
}
if (rc == RC.OK)
{
// Set nDestTruncate to the final number of pages in the destination database. The complication here is that the destination page
// size may be different to the source page size.
//
// If the source page size is smaller than the destination page size, round up. In this case the call to sqlite3OsTruncate() below will
// fix the size of the file. However it is important to call sqlite3PagerTruncateImage() here so that any pages in the
// destination file that lie beyond the nDestTruncate page mark are journalled by PagerCommitPhaseOne() before they are destroyed
// by the file truncation.
Debug.Assert(pgszSrc == Src.GetPageSize());
Debug.Assert(pgszDest == Dest.GetPageSize());
Pid destTruncate;
if (pgszSrc < pgszDest)
{
int ratio = pgszDest / pgszSrc;
destTruncate = (Pid)((srcPage + ratio - 1) / ratio);
if (destTruncate == Btree.PENDING_BYTE_PAGE(Dest.Bt))
destTruncate--;
}
else
destTruncate = (Pid)(srcPage * (pgszSrc / pgszDest));
Debug.Assert(destTruncate > 0);
if (pgszSrc < pgszDest)
{
// If the source page-size is smaller than the destination page-size, two extra things may need to happen:
//
// * The destination may need to be truncated, and
//
// * Data stored on the pages immediately following the pending-byte page in the source database may need to be
// copied into the destination database.
int size = (int)(pgszSrc * srcPage);
VFile file = destPager.get_File();
Debug.Assert(file != null);
Debug.Assert((long)destTruncate * (long)pgszDest >= size || (destTruncate == (int)(Btree.PENDING_BYTE_PAGE(Dest.Bt) - 1) && size >= VFile.PENDING_BYTE && size <= VFile.PENDING_BYTE + pgszDest));
// This block ensures that all data required to recreate the original database has been stored in the journal for pDestPager and the
// journal synced to disk. So at this point we may safely modify the database file in any way, knowing that if a power failure
// occurs, the original database will be reconstructed from the journal file.
uint dstPage;
destPager.Pages(out dstPage);
for (Pid pg = destTruncate; rc == RC.OK && pg <= (Pid)dstPage; pg++)
{
if (pg != Btree.PENDING_BYTE_PAGE(Dest.Bt))
{
IPage pgAsObj;
rc = destPager.Acquire(pg, ref pgAsObj, false);
if (rc == RC.OK)
{
rc = Pager.Write(pgAsObj);
Pager.Unref(pgAsObj);
}
}
}
if (rc == RC.OK)
rc = destPager.CommitPhaseOne(null, true);
// Write the extra pages and truncate the database file as required.
long end = Math.Min(VFile.PENDING_BYTE + pgszDest, size);
for (long off = VFile.PENDING_BYTE + pgszSrc; rc == RC.OK && off < end; off += pgszSrc)
{
Pid srcPg = (Pid)((off / pgszSrc) + 1);
PgHdr srcPgAsObj = null;
rc = srcPager.Acquire(srcPg, ref srcPgAsObj, false);
if (rc == RC.OK)
{
byte[] data = Pager.GetData(srcPgAsObj);
rc = file.Write(data, pgszSrc, off);
}
Pager.Unref(srcPgAsObj);
}
if (rc == RC.OK)
rc = BackupTruncateFile(file, (int)size);
// Sync the database file to disk.
if (rc == RC.OK)
rc = destPager.Sync();
}
else
{
destPager.TruncateImage(destTruncate);
rc = destPager.CommitPhaseOne(null, false);
}
// Finish committing the transaction to the destination database.
if (rc == RC.OK && (rc = Dest.CommitPhaseTwo(false)) == RC.OK)
rc = RC.DONE;
}
}
// If bCloseTrans is true, then this function opened a read transaction on the source database. Close the read transaction here. There is
// no need to check the return values of the btree methods here, as "committing" a read-only transaction cannot fail.
if (closeTrans)
{
#if !DEBUG || COVERAGE_TEST
RC rc2 = Src.CommitPhaseOne(null);
rc2 |= Src.CommitPhaseTwo(false);
Debug.Assert(rc2 == RC.OK);
#else
Src.CommitPhaseOne(null);
Src.CommitPhaseTwo(false);
#endif
}
if (rc == RC.IOERR_NOMEM)
rc = RC.NOMEM;
RC_ = rc;
}
if (DestCtx != null)
MutexEx.Leave(DestCtx.Mutex);
Src.Leave();
MutexEx.Leave(SrcCtx.Mutex);
return rc;
}
internal RC Frames(int v, PgHdr w, Pid x, int y, int z)
{
return(0);
}