示例#1
0
        public BTreePage Split(IFixedLengthKey key, int offset, long pageOffset, float splitFactor)
        {
            ProcessDeferredUpdates();

            if (splitFactor >= 1 || splitFactor < 0.1)
            {
                throw new Exception("BTreePage.Split: splitFactor = " + splitFactor.ToString() + " is not applicable");
            }

            int             mIndex = (int)(_maxCount * splitFactor);
            int             off;
            IFixedLengthKey minKey       = MemoryRead(mIndex, out off).FactoryMethod();
            BTreePage       splittedPage = new BTreePage(
                new BTreeNode(minKey, off, pageOffset, _maxCount - mIndex), _maxCount, _stream, _factoryKey);

            CopyBytes(_bytes, mIndex, splittedPage._bytes, 0, _maxCount - mIndex);
            _treeNode.SetNewCount(mIndex);
            _rightBound = mIndex;
            _modified   = splittedPage._modified = true;

            if (key.CompareTo(minKey) < 0)
            {
                InsertKey(key, offset);
            }
            else
            {
                splittedPage.InsertKey(key, offset);
            }

            return(splittedPage);
        }
示例#2
0
        private void UpdateMinKey(IFixedLengthKey key, int offset)
        {
            int keyCompare = key.CompareTo(_treeNode.MinKey);

            if (keyCompare < 0 || (keyCompare == 0 && offset < _treeNode.MinOffset))
            {
                _treeNode.ChangeMinKey(key.FactoryMethod(), offset);
            }
        }
示例#3
0
        private IFixedLengthKey SearchR(int l, int r, IFixedLengthKey key, int offset, out int index)
        {
            index = -1;
            if (l > r)
            {
                return(null);
            }

            index = r;

            IFixedLengthKey mKey = null;

            while (l < r)
            {
                int m = (l + r) >> 1;
                int off;
                mKey = MemoryRead(m, out off);
                int compareResult = key.CompareTo(mKey);
                if (compareResult == 0 && offset != -1)
                {
                    compareResult = offset - off;
                }
                if (compareResult >= 0)
                {
                    l     = m + 1;
                    index = l;
                }
                else
                {
                    r     = m;
                    index = m;
                }
            }

            return(mKey);
        }
示例#4
0
        public void SearchForRange(IFixedLengthKey beginKey, IFixedLengthKey endKey, ArrayList keys_offsets)
        {
            if (_treeNode.Count == 0)
            {
                return;
            }

            int             index, offset;
            KeyPair         pair;
            IFixedLengthKey deferredKey;
            int             deferredInsertionsIndex = ~GetDeferredInsertionIndex(beginKey, -1);

            IFixedLengthKey foundKey = SearchL(0, _rightBound, beginKey, -1, out index);

            if (foundKey != null && index != -1 && index < _rightBound)
            {
                int deferredDeletionsIndex = ~GetDeferredDeletionIndex(beginKey, -1);
                SetPosition(index);
                for ( ; index < _rightBound; ++index)
                {
                    IFixedLengthKey aKey = MemoryReadNext(out offset);
                    for ( ; deferredInsertionsIndex < _deferredInsertions.Count; ++deferredInsertionsIndex)
                    {
                        pair        = (KeyPair)_deferredInsertions[deferredInsertionsIndex];
                        deferredKey = pair._key;
                        if (deferredKey.CompareTo(aKey) > 0)
                        {
                            break;
                        }
                        if (beginKey.CompareTo(deferredKey) <= 0)
                        {
                            if (endKey.CompareTo(deferredKey) < 0)
                            {
                                break;
                            }
                            keys_offsets.Add(pair);
                        }
                    }
                    if (endKey.CompareTo(aKey) < 0)
                    {
                        break;
                    }
                    bool deleted = false;
                    while (deferredDeletionsIndex < _deferredDeletions.Count)
                    {
                        pair = (KeyPair)_deferredDeletions[deferredDeletionsIndex];
                        int compareResult = pair._key.CompareTo(aKey);
                        if (compareResult == 0)
                        {
                            compareResult = pair._offset - offset;
                        }
                        if (compareResult > 0)
                        {
                            break;
                        }
                        ++deferredDeletionsIndex;
                        if (compareResult == 0)
                        {
                            deleted = true;
                            break;
                        }
                    }
                    if (!deleted)
                    {
                        keys_offsets.Add(new KeyPair(aKey.FactoryMethod(), offset));
                    }
                }
            }
            for ( ; deferredInsertionsIndex < _deferredInsertions.Count; ++deferredInsertionsIndex)
            {
                pair        = (KeyPair)_deferredInsertions[deferredInsertionsIndex];
                deferredKey = pair._key;
                if (beginKey.CompareTo(deferredKey) <= 0)
                {
                    if (endKey.CompareTo(deferredKey) < 0)
                    {
                        break;
                    }
                    keys_offsets.Add(pair);
                }
            }
        }