Exemplo n.º 1
0
        public void Load(byte[] serialization)
        {
            int index     = 0;
            int byteCount = serialization.Length;

            if (this.values.Count != 0 || this.keys.Count != 0)
            {
                throw new BplusTreeException("load into nonempty xBucket not permitted");
            }
            while (index < byteCount)
            {
                // get key prefix and key
                int keylength = BufferFile.Retrieve(serialization, index);
                index += BufferFile.INTSTORAGE;
                byte[] keybytes = new byte[keylength];
                Array.Copy(serialization, index, keybytes, 0, keylength);
                string keystring = BplusTree.BytesToString(keybytes);
                index += keylength;
                // get value prefix and value
                int valuelength = BufferFile.Retrieve(serialization, index);
                index += BufferFile.INTSTORAGE;
                byte[] valuebytes = new byte[valuelength];
                Array.Copy(serialization, index, valuebytes, 0, valuelength);
                // record new key and value
                this.keys.Add(keystring);
                this.values.Add(valuebytes);
                index += valuelength;
            }
            if (index != byteCount)
            {
                throw new BplusTreeException("bad byte count in serialization " + byteCount);
            }
        }
Exemplo n.º 2
0
        public override string PrefixForByteCount(string s, int maxbytecount)
        {
            byte[] inputbytes = BplusTree.StringToBytes(s);
            System.Security.Cryptography.MD5 D = System.Security.Cryptography.MD5.Create();
            byte[] digest      = D.ComputeHash(inputbytes);
            byte[] resultbytes = new byte[maxbytecount];
            // copy digest translating to printable ascii
            for (int i = 0; i < maxbytecount; i++)
            {
                int r = digest[i % digest.Length];
                if (r > 127)
                {
                    r = 256 - r;
                }
                if (r < 0)
                {
                    r = -r;
                }
                //Console.WriteLine(" before "+i+" "+r);
                r = r % 79 + 40; // printable ascii
                //Console.WriteLine(" "+i+" "+r);
                resultbytes[i] = (byte)r;
            }
            string result = BplusTree.BytesToString(resultbytes);

            return(result);
        }