/// <summary>
        /// 从指定的流初始化树
        /// </summary>
        /// <param name="fromFile">指定的流</param>
        /// <param name="seekStart">流起始查询点</param>
        /// <param name="keyLength">键长度</param>
        /// <param name="nodeCapacity">节点容量</param>
        /// <returns>树</returns>
        public static BPlusTree InitializeInStream(Stream fromFile, long seekStart, int keyLength, int nodeCapacity)
        {
            if (fromFile == null)
            {
                throw new ArgumentNullException("fromFile");
            }

            if (fromFile.Length > seekStart)
            {
                throw new BPlusTreeException("Cannot initialize tree inside written area of stream.");
            }

            BPlusTree tree = new BPlusTree(fromFile, seekStart, keyLength, nodeCapacity, (byte)1);

            tree.WriteHeader();
            tree.BlockFile = BlockFile.InitializeInStream(
                fromFile, seekStart + HeaderSize, StorageConstants.BlockFileHeaderPrefix, tree.BlockSize);

            return(tree);
        }
Exemplo n.º 2
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        public static BPlusTreeNode BinaryRoot(
            BPlusTreeNode oldRoot, string splitFirstKey,
            BPlusTreeNode splitNode, BPlusTree tree)
        {
            if (oldRoot == null)
            {
                throw new ArgumentNullException("oldRoot");
            }
            if (splitNode == null)
            {
                throw new ArgumentNullException("splitNode");
            }

            BPlusTreeNode newRoot = MakeRoot(tree, false);

            newRoot._childKeys[0] = splitFirstKey;

            oldRoot.ResetParent(newRoot, 0);
            splitNode.ResetParent(newRoot, 1);

            return(newRoot);
        }
 /// <summary>
 /// 为树构造一个根节点
 /// </summary>
 /// <param name="tree">指定树</param>
 /// <param name="isLeaf">是否为叶节点</param>
 /// <returns>根节点</returns>
 public static BPlusTreeNode MakeRoot(BPlusTree tree, bool isLeaf)
 {
     return(new BPlusTreeNode(tree, null, -1, isLeaf));
 }