Ejemplo n.º 1
0
        private byte *SplitPageInHalf(Page rightPage)
        {
            bool toRight;

            var currentIndex = _page.LastSearchPosition;
            var splitIndex   = _page.NumberOfEntries / 2;

            if (currentIndex <= splitIndex)
            {
                toRight = false;
            }
            else
            {
                toRight = true;

                var leftPageEntryCount  = splitIndex;
                var rightPageEntryCount = _page.NumberOfEntries - leftPageEntryCount + 1;

                if (rightPageEntryCount > leftPageEntryCount)
                {
                    splitIndex++;

                    Debug.Assert(splitIndex < _page.NumberOfEntries);
                }
            }

            PrefixNode[] prefixes = null;

            if (_tree.KeysPrefixing && _page.HasPrefixes)
            {
                prefixes = _page.GetPrefixes();
            }

            if (_page.IsLeaf || prefixes != null)
            {
                splitIndex = AdjustSplitPosition(currentIndex, splitIndex, prefixes, ref toRight);
            }

            var         currentKey = _page.GetNodeKey(splitIndex);
            MemorySlice seperatorKey;

            if (toRight && splitIndex == currentIndex)
            {
                seperatorKey = currentKey.Compare(_newKey) < 0 ? currentKey : _newKey;
            }
            else
            {
                seperatorKey = currentKey;
            }

            Page parentOfRight;

            AddSeparatorToParentPage(rightPage.PageNumber, seperatorKey, out parentOfRight);

            var parentOfPage = _cursor.CurrentPage;

            MemorySlice instance = _page.CreateNewEmptyKey();

            if (prefixes != null)
            {
                for (int i = 0; i < prefixes.Length; i++)
                {
                    var prefix = prefixes[i];

                    rightPage.WritePrefix(new Slice(prefix.ValuePtr, prefix.PrefixLength), i);
                }
            }

            bool addedAsImplicitRef = false;

            if (_page.IsBranch && toRight && seperatorKey == _newKey)
            {
                // _newKey needs to be inserted as first key (BeforeAllKeys) to the right page, so we need to add it before we move entries from the current page
                AddNodeToPage(rightPage, 0, _tree.KeysPrefixing ? (MemorySlice)PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys);
                addedAsImplicitRef = true;
            }

            // move the actual entries from page to right page
            ushort nKeys = _page.NumberOfEntries;

            for (int i = splitIndex; i < nKeys; i++)
            {
                NodeHeader *node = _page.GetNode(i);
                if (_page.IsBranch && rightPage.NumberOfEntries == 0)
                {
                    rightPage.CopyNodeDataToEndOfPage(node, _tree.KeysPrefixing ? (MemorySlice)PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys);
                }
                else
                {
                    _page.SetNodeKey(node, ref instance);
                    var key = rightPage.PrepareKeyToInsert(instance, rightPage.NumberOfEntries);

                    rightPage.CopyNodeDataToEndOfPage(node, key);
                }
            }

            _page.Truncate(_tx, splitIndex);

            byte *pos;

            if (addedAsImplicitRef == false)
            {
                try
                {
                    if (toRight && _cursor.CurrentPage.PageNumber != parentOfRight.PageNumber)
                    {
                        // modify the cursor if we are going to insert to the right page
                        _cursor.Pop();
                        _cursor.Push(parentOfRight);
                    }

                    // actually insert the new key
                    pos = toRight ? InsertNewKey(rightPage) : InsertNewKey(_page);
                }
                catch (InvalidOperationException e)
                {
                    if (e.Message.StartsWith("The page is full and cannot add an entry") == false)
                    {
                        throw;
                    }

                    throw new InvalidOperationException(GatherDetailedDebugInfo(rightPage, currentKey, seperatorKey, currentIndex, splitIndex, toRight), e);
                }
            }
            else
            {
                pos = null;
                _cursor.Push(rightPage);
            }

            if (_page.IsBranch) // remove a branch that has only one entry, the page ref needs to be added to the parent of the current page
            {
                Debug.Assert(_page.NumberOfEntries > 0);
                Debug.Assert(rightPage.NumberOfEntries > 0);

                if (_page.NumberOfEntries == 1)
                {
                    RemoveBranchWithOneEntry(_page, parentOfPage);
                }

                if (rightPage.NumberOfEntries == 1)
                {
                    RemoveBranchWithOneEntry(rightPage, parentOfRight);
                }
            }

            return(pos);
        }
Ejemplo n.º 2
0
        private byte* SplitPageInHalf(Page rightPage)
        {
			bool toRight;

			var currentIndex = _page.LastSearchPosition;
			var splitIndex = _page.NumberOfEntries / 2;

			if (currentIndex <= splitIndex)
			{
				toRight = false;
			}
			else
			{
				toRight = true;

				var leftPageEntryCount = splitIndex;
				var rightPageEntryCount = _page.NumberOfEntries - leftPageEntryCount + 1;

				if (rightPageEntryCount > leftPageEntryCount)
				{
					splitIndex++;

					Debug.Assert(splitIndex < _page.NumberOfEntries);
				}
			}

			PrefixNode[] prefixes = null;

			if (_tree.KeysPrefixing && _page.HasPrefixes)
			{
				prefixes = _page.GetPrefixes();
			}

			if (_page.IsLeaf || prefixes != null)
			{
				splitIndex = AdjustSplitPosition(currentIndex, splitIndex, prefixes, ref toRight);
			}

			var currentKey = _page.GetNodeKey(splitIndex);
			MemorySlice seperatorKey;

			if (toRight && splitIndex == currentIndex)
			{
				seperatorKey = currentKey.Compare(_newKey) < 0 ? currentKey : _newKey;
			}
			else
			{
				seperatorKey = currentKey;
			}

            AddSeparatorToParentPage(rightPage.PageNumber, seperatorKey);

	        MemorySlice instance = _page.CreateNewEmptyKey();

	        if (prefixes != null)
	        {
				for (int i = 0; i < prefixes.Length; i++)
				{
					var prefix = prefixes[i];

					rightPage.WritePrefix(new Slice(prefix.ValuePtr, prefix.PrefixLength), i);
				}
	        }

	        bool addedAsImplicitRef = false;

			if (_page.IsBranch && toRight && seperatorKey == _newKey)
			{
				// _newKey needs to be inserted as first key (BeforeAllKeys) to the right page, so we need to add it before we move entries from the current page
				AddNodeToPage(rightPage, 0, _tree.KeysPrefixing ? (MemorySlice)PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys);
				addedAsImplicitRef = true;
			}

	        // move the actual entries from page to right page
            ushort nKeys = _page.NumberOfEntries;
            for (int i = splitIndex; i < nKeys; i++)
            {
                NodeHeader* node = _page.GetNode(i);
                if (_page.IsBranch && rightPage.NumberOfEntries == 0)
                {
                    rightPage.CopyNodeDataToEndOfPage(node, _tree.KeysPrefixing ? (MemorySlice) PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys);
                }
                else
                {
	                _page.SetNodeKey(node, ref instance);
	                var key = rightPage.PrepareKeyToInsert(instance, rightPage.NumberOfEntries);

					rightPage.CopyNodeDataToEndOfPage(node, key);
                }
            }

            _page.Truncate(_tx, splitIndex);

			byte* pos;

	        if (addedAsImplicitRef == false)
	        {
				try
				{
					// actually insert the new key
					pos = toRight ? InsertNewKey(rightPage) : InsertNewKey(_page);
				}
				catch (InvalidOperationException e)
				{
					if (e.Message.StartsWith("The page is full and cannot add an entry") == false)
						throw;

					throw new InvalidOperationException(GatherDetailedDebugInfo(rightPage, currentKey, seperatorKey, currentIndex, splitIndex, toRight), e);
				}
	        }
	        else
	        {
				pos = null;
				_cursor.Push(rightPage);
	        }

	        if (_page.IsBranch) // remove a branch that has only one entry, the page ref needs to be added to the parent of the current page
			{
				Debug.Assert(_page.NumberOfEntries > 0);
				Debug.Assert(rightPage.NumberOfEntries > 0);

				if (_page.NumberOfEntries == 1)
					RemoveBranchWithOneEntry(_page, _cursor.ParentPage);

				if (rightPage.NumberOfEntries == 1)
					RemoveBranchWithOneEntry(rightPage, _cursor.ParentPage);
			}

			return pos;
        }
Ejemplo n.º 3
0
        private byte* SplitPageInHalf(Page rightPage)
        {
            int currentIndex = _page.LastSearchPosition;
            bool newPosition = true;
            int splitIndex = _page.NumberOfEntries/2;
            if (currentIndex < splitIndex)
                newPosition = false;

	        PrefixNode[] prefixes = null;

	        if (_tree.KeysPrefixing && _page.HasPrefixes)
	        {
		        prefixes = _page.GetPrefixes();
	        }

	        if (_page.IsLeaf || prefixes != null)
            {
                splitIndex = AdjustSplitPosition(currentIndex, splitIndex, prefixes, ref newPosition);
            }

	        var currentKey = _page.GetNodeKey(splitIndex);

            // here the current key is the separator key and can go either way, so 
            // use newPosition to decide if it stays on the left node or moves to the right
            MemorySlice seperatorKey;
            if (currentIndex == splitIndex && newPosition)
            {
                seperatorKey = currentKey.Compare(_newKey) < 0 ? currentKey : _newKey;
            }
            else
            {
                seperatorKey = currentKey;
            }

            AddSeparatorToParentPage(rightPage.PageNumber, seperatorKey);

	        MemorySlice instance = _page.CreateNewEmptyKey();

	        if (prefixes != null)
	        {
				for (int i = 0; i < prefixes.Length; i++)
				{
					var prefix = prefixes[i];

					rightPage.WritePrefix(new Slice(prefix.ValuePtr, prefix.PrefixLength), i);
				}
	        }

	        // move the actual entries from page to right page
            ushort nKeys = _page.NumberOfEntries;
            for (int i = splitIndex; i < nKeys; i++)
            {
                NodeHeader* node = _page.GetNode(i);
                if (_page.IsBranch && rightPage.NumberOfEntries == 0)
                {
                    rightPage.CopyNodeDataToEndOfPage(node, _tree.KeysPrefixing ? (MemorySlice) PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys);
                }
                else
                {
	                _page.SetNodeKey(node, ref instance);
	                var key = rightPage.PrepareKeyToInsert(instance, rightPage.NumberOfEntries);

					rightPage.CopyNodeDataToEndOfPage(node, key);
                }
            }
            _page.Truncate(_tx, splitIndex);

            // actually insert the new key
			try
			{
				return (currentIndex > splitIndex || newPosition && currentIndex == splitIndex)
					? InsertNewKey(rightPage)
					: InsertNewKey(_page);
			}
			catch (InvalidOperationException e)
			{
				if (e.Message.StartsWith("The page is full and cannot add an entry"))
				{
					var debugInfo = new StringBuilder();

					debugInfo.AppendFormat("\r\n_tree.Name: {0}\r\n", _tree.Name);
					debugInfo.AppendFormat("_newKey: {0}, _len: {1}, needed space: {2}\r\n", _newKey, _len, _page.GetRequiredSpace(_newKey, _len));
					debugInfo.AppendFormat("currentKey: {0}, seperatorKey: {1}\r\n", currentKey, seperatorKey);
					debugInfo.AppendFormat("currentIndex: {0}\r\n", currentIndex);
					debugInfo.AppendFormat("splitIndex: {0}\r\n", splitIndex);
					debugInfo.AppendFormat("newPosition: {0}\r\n", newPosition);

					debugInfo.AppendFormat("_page info: flags - {0}, # of entries {1}, size left: {2}, calculated size left: {3}\r\n", _page.Flags, _page.NumberOfEntries, _page.SizeLeft, _page.CalcSizeLeft());

					for (int i = 0; i < _page.NumberOfEntries; i++)
					{
						var node = _page.GetNode(i);
						var key = _page.GetNodeKey(node);
						debugInfo.AppendFormat("{0} - {2} {1}\r\n", key,
							node->DataSize, node->Flags == NodeFlags.Data ? "Size" : "Page");
					}

					debugInfo.AppendFormat("rightPage info: flags - {0}, # of entries {1}, size left: {2}, calculated size left: {3}\r\n", rightPage.Flags, rightPage.NumberOfEntries, rightPage.SizeLeft, rightPage.CalcSizeLeft());

					for (int i = 0; i < rightPage.NumberOfEntries; i++)
					{
						var node = rightPage.GetNode(i);
						var key = rightPage.GetNodeKey(node);
						debugInfo.AppendFormat("{0} - {2} {1}\r\n", key,
							node->DataSize, node->Flags == NodeFlags.Data ? "Size" : "Page");
					}

					throw new InvalidOperationException(debugInfo.ToString(), e);
				}

				throw;
			}

        }
Ejemplo n.º 4
0
        private byte *SplitPageInHalf(Page rightPage)
        {
            int  currentIndex = _page.LastSearchPosition;
            bool newPosition  = true;
            int  splitIndex   = _page.NumberOfEntries / 2;

            if (currentIndex < splitIndex)
            {
                newPosition = false;
            }

            PrefixNode[] prefixes = null;

            if (_tree.KeysPrefixing && _page.HasPrefixes)
            {
                prefixes = _page.GetPrefixes();
            }

            if (_page.IsLeaf || prefixes != null)
            {
                splitIndex = AdjustSplitPosition(currentIndex, splitIndex, prefixes, ref newPosition);
            }

            var currentKey = _page.GetNodeKey(splitIndex);

            // here the current key is the separator key and can go either way, so
            // use newPosition to decide if it stays on the left node or moves to the right
            MemorySlice seperatorKey;

            if (currentIndex == splitIndex && newPosition)
            {
                seperatorKey = currentKey.Compare(_newKey) < 0 ? currentKey : _newKey;
            }
            else
            {
                seperatorKey = currentKey;
            }

            AddSeparatorToParentPage(rightPage.PageNumber, seperatorKey);

            MemorySlice instance = _page.CreateNewEmptyKey();

            if (prefixes != null)
            {
                for (int i = 0; i < prefixes.Length; i++)
                {
                    var prefix = prefixes[i];

                    rightPage.WritePrefix(new Slice(prefix.ValuePtr, prefix.PrefixLength), i);
                }
            }

            // move the actual entries from page to right page
            ushort nKeys = _page.NumberOfEntries;

            for (int i = splitIndex; i < nKeys; i++)
            {
                NodeHeader *node = _page.GetNode(i);
                if (_page.IsBranch && rightPage.NumberOfEntries == 0)
                {
                    rightPage.CopyNodeDataToEndOfPage(node, _tree.KeysPrefixing ? (MemorySlice)PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys);
                }
                else
                {
                    _page.SetNodeKey(node, ref instance);
                    var key = rightPage.PrepareKeyToInsert(instance, rightPage.NumberOfEntries);

                    rightPage.CopyNodeDataToEndOfPage(node, key);
                }
            }
            _page.Truncate(_tx, splitIndex);

            // actually insert the new key
            try
            {
                return((currentIndex > splitIndex || newPosition && currentIndex == splitIndex)
                                        ? InsertNewKey(rightPage)
                                        : InsertNewKey(_page));
            }
            catch (InvalidOperationException e)
            {
                if (e.Message.StartsWith("The page is full and cannot add an entry"))
                {
                    var debugInfo = new StringBuilder();

                    debugInfo.AppendFormat("\r\n_tree.Name: {0}\r\n", _tree.Name);
                    debugInfo.AppendFormat("_newKey: {0}, _len: {1}, needed space: {2}\r\n", _newKey, _len, _page.GetRequiredSpace(_newKey, _len));
                    debugInfo.AppendFormat("currentKey: {0}, seperatorKey: {1}\r\n", currentKey, seperatorKey);
                    debugInfo.AppendFormat("currentIndex: {0}\r\n", currentIndex);
                    debugInfo.AppendFormat("splitIndex: {0}\r\n", splitIndex);
                    debugInfo.AppendFormat("newPosition: {0}\r\n", newPosition);

                    debugInfo.AppendFormat("_page info: flags - {0}, # of entries {1}, size left: {2}, calculated size left: {3}\r\n", _page.Flags, _page.NumberOfEntries, _page.SizeLeft, _page.CalcSizeLeft());

                    for (int i = 0; i < _page.NumberOfEntries; i++)
                    {
                        var node = _page.GetNode(i);
                        var key  = _page.GetNodeKey(node);
                        debugInfo.AppendFormat("{0} - {2} {1}\r\n", key,
                                               node->DataSize, node->Flags == NodeFlags.Data ? "Size" : "Page");
                    }

                    debugInfo.AppendFormat("rightPage info: flags - {0}, # of entries {1}, size left: {2}, calculated size left: {3}\r\n", rightPage.Flags, rightPage.NumberOfEntries, rightPage.SizeLeft, rightPage.CalcSizeLeft());

                    for (int i = 0; i < rightPage.NumberOfEntries; i++)
                    {
                        var node = rightPage.GetNode(i);
                        var key  = rightPage.GetNodeKey(node);
                        debugInfo.AppendFormat("{0} - {2} {1}\r\n", key,
                                               node->DataSize, node->Flags == NodeFlags.Data ? "Size" : "Page");
                    }

                    throw new InvalidOperationException(debugInfo.ToString(), e);
                }

                throw;
            }
        }