// was:sqlite3BtreeCursor
public RC Cursor(int iTable, bool wrFlag, KeyInfo pKeyInfo, BtreeCursor pCur)
{
sqlite3BtreeEnter();
var rc = btreeCursor(iTable, wrFlag, pKeyInfo, pCur);
sqlite3BtreeLeave();
return rc;
}
internal RC saveAllCursors(Pgno iRoot, BtreeCursor pExcept)
{
Debug.Assert(MutexEx.Held(this.Mutex));
Debug.Assert(pExcept == null || pExcept.Shared == this);
for (var p = this.Cursors; p != null; p = p.Next)
{
if (p != pExcept && (0 == iRoot || p.RootID == iRoot) && p.State == CURSOR.VALID)
{
var rc = p.SavePosition();
if (rc != RC.OK)
{
return(rc);
}
}
}
return(RC.OK);
}
public uint[] OverflowIDs; // Cache of overflow page locations
#endif
#region Methods
// was:sqlite3BtreeCursorZero
public void Zero()
{
Next = null;
Prev = null;
KeyInfo = null;
RootID = 0;
_cachedRowID = 0;
Info = new MemPage.CellInfo();
Writeable = false;
AtLast = false;
ValidNKey = false;
State = 0;
Key = null;
NKey = 0;
SkipNext = 0;
#if !SQLITE_OMIT_INCRBLOB
IsIncrblob = false;
OverflowIDs = null;
#endif
PageID = 0;
}
public MemPage[] Pages = new MemPage[BTCURSOR_MAX_DEPTH]; // Pages from root to current page
// was:sqlite3BtreeCursorZero
public void Zero()
{
Next = null;
Prev = null;
KeyInfo = null;
RootID = 0;
_cachedRowID = 0;
Info = new MemPage.CellInfo();
Writeable = false;
AtLast = false;
ValidNKey = false;
State = 0;
Key = null;
NKey = 0;
SkipNext = 0;
#if !SQLITE_OMIT_INCRBLOB
IsIncrblob = false;
OverflowIDs = null;
#endif
PageID = 0;
}
internal RC btreeCursor(int iTable, bool wrFlag, KeyInfo pKeyInfo, BtreeCursor pCur)
{
Debug.Assert(sqlite3BtreeHoldsMutex());
// The following Debug.Assert statements verify that if this is a sharable b-tree database, the connection is holding the required table locks,
// and that no other connection has any open cursor that conflicts with this lock.
Debug.Assert(hasSharedCacheTableLock((uint)iTable, (pKeyInfo != null), (wrFlag ? LOCK.READ : LOCK.WRITE)));
Debug.Assert(!wrFlag || !hasReadConflicts((uint)iTable));
// Assert that the caller has opened the required transaction.
Debug.Assert(this.InTransaction > TRANS.NONE);
Debug.Assert(!wrFlag || this.InTransaction == TRANS.WRITE);
var pBt = this.Shared; // Shared b-tree handle
Debug.Assert(pBt.Page1 != null && pBt.Page1.Data != null);
if (Check.NEVER(wrFlag && pBt.ReadOnly))
{
return(RC.READONLY);
}
if (iTable == 1 && pBt.btreePagecount() == 0)
{
return(RC.EMPTY);
}
// Now that no other errors can occur, finish filling in the BtCursor variables and link the cursor into the BtShared list.
pCur.RootID = (Pgno)iTable;
pCur.PageID = -1;
pCur.KeyInfo = pKeyInfo;
pCur.Tree = this;
pCur.Shared = pBt;
pCur.Writeable = wrFlag;
pCur.Next = pBt.Cursors;
if (pCur.Next != null)
{
pCur.Next.Prev = pCur;
}
pBt.Cursors = pCur;
pCur.State = CURSOR.INVALID;
pCur._cachedRowID = 0;
return(RC.OK);
}
// was:invalidateOverflowCache
internal static void invalidateOverflowCache(BtreeCursor cursor)
{
Debug.Assert(cursor.HoldsMutex());
cursor.OverflowIDs = null;
}
// was:invalidateOverflowCache
internal static void invalidateOverflowCache(BtreeCursor cursor)
{
Debug.Assert(cursor.HoldsMutex());
cursor.OverflowIDs = null;
}
// was:sqlite3BtreeCursor
public RC Cursor(int iTable, bool wrFlag, KeyInfo pKeyInfo, BtreeCursor pCur)
{
sqlite3BtreeEnter();
var rc = btreeCursor(iTable, wrFlag, pKeyInfo, pCur);
sqlite3BtreeLeave();
return rc;
}
internal RC saveAllCursors(Pgno iRoot, BtreeCursor pExcept)
{
Debug.Assert(MutexEx.Held(this.Mutex));
Debug.Assert(pExcept == null || pExcept.Shared == this);
for (var p = this.Cursors; p != null; p = p.Next)
if (p != pExcept && (0 == iRoot || p.RootID == iRoot) && p.State == CURSOR.VALID)
{
var rc = p.SavePosition();
if (rc != RC.OK)
return rc;
}
return RC.OK;
}
internal RC btreeCursor(int iTable, bool wrFlag, KeyInfo pKeyInfo, BtreeCursor pCur)
{
Debug.Assert(sqlite3BtreeHoldsMutex());
// The following Debug.Assert statements verify that if this is a sharable b-tree database, the connection is holding the required table locks,
// and that no other connection has any open cursor that conflicts with this lock.
Debug.Assert(hasSharedCacheTableLock((uint)iTable, (pKeyInfo != null), (wrFlag ? LOCK.READ : LOCK.WRITE)));
Debug.Assert(!wrFlag || !hasReadConflicts((uint)iTable));
// Assert that the caller has opened the required transaction.
Debug.Assert(this.InTransaction > TRANS.NONE);
Debug.Assert(!wrFlag || this.InTransaction == TRANS.WRITE);
var pBt = this.Shared; // Shared b-tree handle
Debug.Assert(pBt.Page1 != null && pBt.Page1.Data != null);
if (Check.NEVER(wrFlag && pBt.ReadOnly))
return RC.READONLY;
if (iTable == 1 && pBt.btreePagecount() == 0)
return RC.EMPTY;
// Now that no other errors can occur, finish filling in the BtCursor variables and link the cursor into the BtShared list.
pCur.RootID = (Pgno)iTable;
pCur.PageID = -1;
pCur.KeyInfo = pKeyInfo;
pCur.Tree = this;
pCur.Shared = pBt;
pCur.Writeable = wrFlag;
pCur.Next = pBt.Cursors;
if (pCur.Next != null)
pCur.Next.Prev = pCur;
pBt.Cursors = pCur;
pCur.State = CURSOR.INVALID;
pCur._cachedRowID = 0;
return RC.OK;
}
