fileworks.cs

按照Clifford A . Shaffer《数据结构与算法分析（第二版）》指导

                {
                    resultLine.Add(str);
                }
            }
            return true;
        }

        public bool readAllLines(ArrayList arrayResultLines)
        {
            FileInfo ofd;
            FileStream reader;
            ofd = new FileInfo(nameofMainRecs);
            if (ofd.Exists && ((ofd.Attributes & FileAttributes.ReadOnly) == 0))
            {
                byte[] allLines = new byte[sizeofLine * MaxOffset];
                reader = ofd.Open(FileMode.Open, FileAccess.Read, FileShare.Read);
                //reader.Seek((long)thisOffset * sizeofLine, SeekOrigin.Begin);
                reader.Read(allLines, 0, allLines.Length);

                byte[] thisline = new byte[sizeofLine];
                int j = 0;//index for EmptyRecs
                EmptyRecs.Sort();
                for (int i = 0; i < MaxOffset; i++)// i is the index of valid line
                {
                    //跳过EmptyRecs
                    if (j < EmptyRecs.Count && i == (int)EmptyRecs[j])
                    {
                        //i++;//这里真阴险,都continue了,上面居然还会i++
                        j++;
                        continue;
                    }
                    Array.Copy(allLines,  i * sizeofLine, thisline, 0, sizeofLine);
                    string tStr = Encoding.Default.GetString(thisline);
                    string[] strArray;//= new string [];
                    strArray = tStr.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                    ArrayList resultLine = new ArrayList();
                    foreach (string str in strArray)
                    {
                        resultLine.Add(str);
                    }
                    arrayResultLines.Add(resultLine);
                }
                reader.Close();
            }
            return true;
        }

        //重载一个无参数的版本, C#......怀念C++
        public bool readAllFromFile()
        {
            return (readAllFromFile("index.bin"));

        }

        //complete
        public bool readAllFromFile(string allFileNames)
        {
            nameofIndex = allFileNames;

            this.EmptyRecs.Clear();
            this.filenames_Of_trees.Clear();
            this.insertBuffer.Clear();
            this.removeBuffer.Clear();
            this.Trees.Clear();

            //FileInfo ifd = new FileInfo(allFileNames);
            FileStream SReader = File.OpenRead(allFileNames);//ifd.OpenRead();

            byte[] byteArray = new byte[SReader.Length];
            SReader.Read(byteArray, 0, byteArray.Length);
            string longstr = Encoding.Default.GetString(byteArray);
            string[] strArray = longstr.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries);//分行,第二个参数用来去除所有空string
            nameofMainRecs = strArray[0];//第一行是主记录文件名
            nameofEmptyRecs = strArray[1];//第二行是EmptyRecs文件名
            MaxOffset = Int32.Parse(strArray[2]);//第三行是MaxOffset (in int)
            string[] sizeofRecord = (strArray[3]).Split(new string[] { " ", "\t" }, StringSplitOptions.RemoveEmptyEntries);//第四行是sizeofRec的ArrayList拉
            int sizeofSingleRec = 0;
            sizeofLine = 0;//清零这个搞掰我了
            sizeofRec.Clear();
            foreach (string str in sizeofRecord)
            {
                sizeofSingleRec = Int32.Parse(str);
                sizeofRec.Add(sizeofSingleRec);
                sizeofLine += sizeofSingleRec + 1;//1 for blank
            }
            SReader.Close();//居然忘记关闭这里

            //以下各行都是树的文件名

            //下面这个for循环建树 i的初值为3
            for (int i = 4; i < strArray.Length; i++)
            {
                string [] str = (strArray[i]).Split(new char[] {' '}, 3, StringSplitOptions.RemoveEmptyEntries);
                filenames_Of_trees.Add(str[2]);//不用多说
                SReader = File.OpenRead(str[2]);
                if (str[0].Equals("int") && str[1].Equals("int"))
                {
                    Trees.Add(build_int_intTree(SReader));
                }
                else if (str[0].Equals("string") && str[1].Equals("int"))
                {
                    Trees.Add(build_str_intTree(SReader));
                }
                else
                {
                    return false;
                }
                
            }

            //下面这个foreach循环建EmptyRecs
            SReader = File.OpenRead(strArray[1]);
            byteArray = new byte[SReader.Length];
            SReader.Read(byteArray, 0, byteArray.Length);
            SReader.Close();//这里关闭了流
            string longstr1 = Encoding.Default.GetString(byteArray);//用了不同的string name
            string[] strArray1 = longstr1.Split(new char[] { ' ', '\t' },  StringSplitOptions.RemoveEmptyEntries);//分开各个数
            foreach (string str in strArray1)
            {
                if (str.Length == 0)
                {
                    break;
                }
                EmptyRecs.Add(Int32.Parse(str));
            }

            return true;
        }

        //complete
        //have to close file_of_a_tree
        public Object build_int_intTree(FileStream file_of_a_tree)
        {
            Treeworks.BPTree<int, int, intintCompare> thistree = new Treeworks.BPTree<int, int, intintCompare>();
            
            byte[] byteArray = new byte[file_of_a_tree.Length];
            file_of_a_tree.Read(byteArray, 0, byteArray.Length);
            string longstr = Encoding.Default.GetString(byteArray);
            string[] strArray = longstr.Split('\n');//分行

            foreach (string str in strArray)
            {
                if (str.Equals(""))//唉,居然会有空串要跳过
                    break;//continue;
                string[] s = str.Split();//行内分节点
                for (int i = 1; i < s.Length - 1; i++)//小心这里 i 的初值为1
                {
                    if (s[i].Equals(""))
                        break;//continue;
                    thistree.insert(Int32.Parse(s[0]), Int32.Parse(s[i]));
                }
            }
            file_of_a_tree.Close();
            return thistree;
        }

        public Object build_str_intTree(FileStream file_of_a_tree)
        {
           Treeworks.BPTree<string, int, strstrCompare> thistree = new Treeworks.BPTree<string, int, strstrCompare>();

            byte[] byteArray = new byte[file_of_a_tree.Length];
            file_of_a_tree.Read(byteArray, 0, byteArray.Length);
            string longstr = Encoding.Default.GetString(byteArray);
            string[] strArray = longstr.Split('\n');//分行

            foreach (string str in strArray)
            {
                if (str.Equals(""))//唉,居然会有空串要跳过
                    break;//continue;
                string[] s = str.Split();//行内分节点
                for (int i = 1; i < s.Length - 1; i++)//小心这里 i 的初值为1
                {
                    if (s[i].Equals(""))
                        break;//continue;
                    thistree.insert(s[0], Int32.Parse(s[i]));
                }
            }
            file_of_a_tree.Close();
            return thistree;
        }

        //complete
        public int insert(ArrayList list, ArrayList trees)
        {
            int i = 0;
            ArrayList insertlist = new ArrayList(list.Count + 1);//不new一下还真不行,还是c++按值传递好,c#不爽
            foreach (Object elem in list)
            {
                insertlist.Add(elem);
            }
            //bool insertsucc = true;

            //insertlist.TrimToSize();
            //string[] elements = (String[])insertlist.ToArray(typeof(string));//好像没必要这么麻烦

            int thisOffset = 0;//应该插入的Offset//是第几条记录

            if (EmptyRecs.Count == 0)//MainRecs中没有空位
            {
                thisOffset = MaxOffset;
                MaxOffset++;
            }
            else//MainRecs中有空位
            {
                EmptyRecs.Sort();
                thisOffset = (int)EmptyRecs[0];
                EmptyRecs.RemoveAt(0);
            }
            //insertlist.

            i = 0;
            foreach (Object tree in trees)
            {
                //insertsucc &= 
                if (tree is Treeworks.BPTree<int, int, intintCompare>)
                {
                    ((Treeworks.BPTree<int, int, intintCompare>)tree).insert(Convert.ToInt32(insertlist[i]), thisOffset);//先做了int再说
                }
                else if (tree is Treeworks.BPTree<string, int, strstrCompare>)
                {
                    ((Treeworks.BPTree<string, int, strstrCompare>)tree).insert(insertlist[i].ToString(), thisOffset);//这就做了string了
                }
                i++;
            }

            insertlist.Add(thisOffset);//插入buffer前把offset插入该记录的最后

            //if (removeBuffer.Contains(insertlist))//如果只是buffer操作
            //{
            //    removeBuffer.Remove(insertlist);
            //}
            i = 0;
            int j = 0;
            int flag = 0;
            //因为不知道怎么重写ArrayList.Equals();不得已的办法
            foreach (ArrayList testlist in removeBuffer)
            {
                i = 0;
                foreach (Object elem in testlist)
                {
                    if (!elem.Equals(insertlist[i]))//不相等就跳出
                    {
                        //flag = 1;
                        break;
                    }
                    i++;
                }
                if (i == testlist.Count)//相等就跳出
                {
                    flag = 1;
                    break;
                }
                j++;
            }
            if (flag == 1)
            {
                removeBuffer.RemoveAt(j);
            }

            insertBuffer.Add(insertlist);//插入buffer
            return thisOffset;
        }

        //complete
        public bool remove(ArrayList list, ref Object thisOffset, ArrayList trees)
        {
            int i = 0;
            ArrayList removelist = new ArrayList(list.Count + 1);
            foreach (Object elem in list)
            {
                removelist.Add(elem);
            }

            Object thisremoveOffset;// = thisOffset;
            i = 0;
            foreach (Object tree in trees)
            {
                //insertsucc &= 
                thisremoveOffset = thisOffset;
                //一开始忘了要在循环里面反复赋值,因为一旦没有,null就会被赋给这个
                if (tree is Treeworks.BPTree<int, int, intintCompare>)
                {
                    ((Treeworks.BPTree<int, int, intintCompare>)tree).remove(Convert.ToInt32(removelist[i]), ref thisremoveOffset);//先做了int再说
                }
                else if (tree is Treeworks.BPTree<string, int, strstrCompare>)
                {
                    ((Treeworks.BPTree<string, int, strstrCompare>)tree).remove(removelist[i].ToString(), ref thisremoveOffset);
                }
                else 
                {
                    //do nothing
                }
                i++;
            }