/// <summary>
        /// Increments/decrements the value at the specified key by inc.
        ///
        /// Note that the server uses a 32-bit unsigned integer, and checks for
        /// underflow. In the event of underflow, the result will be zero.  Because
        /// Java lacks unsigned types, the value is returned as a 64-bit integer.
        /// The server will only decrement a value if it already exists;
        /// if a value is not found, -1 will be returned.
        ///
        /// TODO: C# has unsigned types.  We can fix this.
        /// </summary>
        /// <param name="cmdname">increment/decrement</param>
        /// <param name="key">cache key</param>
        /// <param name="inc">amount to incr or decr</param>
        /// <param name="hashCode">if not null, then the int hashcode to use</param>
        /// <returns>new value or -1 if not exist</returns>
        private long IncrementOrDecrement(string cmdname, string key, long inc, object hashCode)
        {
            key = Prefix + key;

            // get SockIO obj for given cache key
            SockIO sock = SockIOPool.GetInstance(_poolName).GetSock(key, hashCode);

            if (sock == null)
            {
                return(-1);
            }

            try
            {
                string cmd = cmdname + " " + key + " " + inc + "\r\n";

                sock.Write(Encoding.UTF8.GetBytes(cmd));
                sock.Flush();

                // get result back
                string line = sock.ReadLine();

                if (new Regex("\\d+").Match(line).Success)
                {
                    // return sock to pool and return result
                    sock.Close();
                    return(long.Parse(line, new NumberFormatInfo()));
                }
            }
            catch (IOException e)
            {
                try
                {
                    sock.TrueClose();
                }
                finally
                {
                    sock = null;
                }
            }

            if (sock != null)
            {
                sock.Close();
            }
            return(-1);
        }
		/// <summary>
		/// This method loads the data from cache into a Hashtable.
		/// 
		/// Pass a SockIO object which is ready to receive data and a Hashtable
		/// to store the results.
		/// </summary>
		/// <param name="sock">socket waiting to pass back data</param>
		/// <param name="hm">hashmap to store data into</param>
		/// <param name="asString">if true, and if we are using NativehHandler, return string val</param>
		private void LoadItems(SockIO sock, Hashtable hm, bool asString) 
		{
			while(true) 
			{
				string line = sock.ReadLine();

				if(line.StartsWith(VALUE)) 
				{
					string[] info = line.Split(' ');
					string key    = info[1];
					int flag      = int.Parse(info[2], new NumberFormatInfo());
					int length    = int.Parse(info[3], new NumberFormatInfo());
				
					// read obj into buffer
					byte[] buf = new byte[length];
					sock.Read(buf);
					sock.ClearEndOfLine();

					// ready object
					object o=null;
				
					// check for compression
					if((flag & F_COMPRESSED) != 0)
					{
					    MemoryStream mem = null;
					    GZipStream gzi = null;
						try 
						{
							// read the input stream, and write to a byte array output stream since
							// we have to read into a byte array, but we don't know how large it
							// will need to be, and we don't want to resize it a bunch
                            mem = new MemoryStream(buf.Length);
						    gzi = new GZipStream(new MemoryStream(buf), CompressionMode.Compress);
							
							int count;
							var tmp = new byte[2048];
                            while ((count = gzi.Read(tmp, 0, tmp.Length)) > 0)
                            {
                                mem.Write(tmp, 0, count);
                            }

						    // store uncompressed back to buffer
							buf = mem.ToArray();
						}
						finally
						{
						    if(mem!=null)
						    {
						        mem.Close();
                                mem.Dispose();
						    }
                            if(gzi != null)
                            {
                                gzi.Close();
                                gzi.Dispose();
                            }
						}
					}

					// we can only take out serialized objects
					if((flag & F_SERIALIZED) == 0) 
					{
						if(_primitiveAsString || asString) 
						{
							o = Encoding.GetEncoding(_defaultEncoding).GetString(buf);
						}
						else 
						{
							// decoding object
							try 
							{
								o = NativeHandler.Decode(buf);    
							}
							catch(Exception e) 
							{
                                return;
							}
						}
					}
					else 
					{
						// deserialize if the data is serialized
					    MemoryStream memStream = null;
						try 
						{
							memStream = new MemoryStream(buf);
							o = new BinaryFormatter().Deserialize(memStream);
						}
						catch(SerializationException e) 
						{
						}
                        finally
						{
						    if(memStream != null)
						    {
						        memStream.Close();
                                memStream.Dispose();
						    }
						}
					}

					// store the object into the cache
					hm[ key ] =  o ;
				}
				else if(END == line) 
				{
					break;
				}
			}
		}
        /// <summary>
        /// Stores data to cache.
        ///
        /// If data does not already exist for this key on the server, or if the key is being
        /// deleted, the specified value will not be stored.
        /// The server will automatically delete the value when the expiration time has been reached.
        ///
        /// If compression is enabled, and the data is longer than the compression threshold
        /// the data will be stored in compressed form.
        ///
        /// As of the current release, all objects stored will use .NET serialization.
        /// </summary>
        /// <param name="cmdname">action to take (set, add, replace)</param>
        /// <param name="key">key to store cache under</param>
        /// <param name="obj">object to cache</param>
        /// <param name="expiry">expiration</param>
        /// <param name="hashCode">if not null, then the int hashcode to use</param>
        /// <param name="asString">store this object as a string?</param>
        /// <returns>true/false indicating success</returns>
        private bool Set(string cmdname, string key, object obj, DateTime expiry, object hashCode, bool asString)
        {
            if (expiry < DateTime.Now)
            {
                return(true);
            }

            if (cmdname == null || cmdname.Trim().Length == 0 || string.IsNullOrEmpty(key))
            {
                return(false);
            }
            key = Prefix + key;

            // get SockIO obj
            SockIO sock = SockIOPool.GetInstance(_poolName).GetSock(key, hashCode);

            if (sock == null)
            {
                return(false);
            }

            if (expiry == DateTime.MaxValue)
            {
                expiry = new DateTime(0);
            }

            // store flags
            int flags = 0;

            // byte array to hold data
            byte[] val;
            int    length = 0;

            // useful for sharing data between .NET and non-.NET
            // and also for storing ints for the increment method
            if (NativeHandler.IsHandled(obj))
            {
                if (asString)
                {
                    if (obj != null)
                    {
                        try
                        {
                            val    = Encoding.UTF8.GetBytes(obj.ToString());
                            length = val.Length;
                        }
                        catch
                        {
                            sock.Close();
                            sock = null;
                            return(false);
                        }
                    }
                    else
                    {
                        val    = new byte[0];
                        length = 0;
                    }
                }
                else
                {
                    try
                    {
                        val    = NativeHandler.Encode(obj);
                        length = val.Length;
                    }
                    catch
                    {
                        sock.Close();
                        sock = null;
                        return(false);
                    }
                }
            }
            else
            {
                if (obj != null)
                {
                    // always serialize for non-primitive types
                    try
                    {
                        var memStream = new MemoryStream();
                        new BinaryFormatter().Serialize(memStream, obj);
                        val    = memStream.GetBuffer();
                        length = (int)memStream.Length;
                        flags |= F_SERIALIZED;
                    }
                    catch
                    {
                        // return socket to pool and bail
                        sock.Close();
                        sock = null;
                        return(false);
                    }
                }
                else
                {
                    val    = new byte[0];
                    length = 0;
                }
            }

            // now try to compress if we want to
            // and if the length is over the threshold
            if (_compressEnable && length > _compressThreshold)
            {
                MemoryStream memoryStream = null;
                GZipStream   gos          = null;
                try
                {
                    memoryStream = new MemoryStream();
                    gos          = new GZipStream(memoryStream, CompressionMode.Compress);
                    gos.Write(val, 0, length);
                    gos.Flush();

                    // store it and set compression flag
                    val    = memoryStream.GetBuffer();
                    length = (int)memoryStream.Length;
                    flags |= F_COMPRESSED;
                }
                finally
                {
                    if (memoryStream != null)
                    {
                        memoryStream.Close();
                        memoryStream.Dispose();
                    }
                    if (gos != null)
                    {
                        gos.Close();
                        gos.Dispose();
                    }
                }
            }

            // now write the data to the cache server
            try
            {
                string cmd = cmdname + " " + key + " " + flags + " "
                             + GetExpirationTime(expiry) + " " + length + "\r\n";
                sock.Write(Encoding.UTF8.GetBytes(cmd));
                sock.Write(val, 0, length);
                sock.Write(Encoding.UTF8.GetBytes("\r\n"));
                sock.Flush();

                // get result code
                string line = sock.ReadLine();

                if (STORED == line)
                {
                    sock.Close();
                    sock = null;
                    return(true);
                }
            }
            catch
            {
                try
                {
                    if (sock != null)
                    {
                        sock.TrueClose();
                    }
                }
                finally
                {
                    sock = null;
                }
            }

            if (sock != null)
            {
                sock.Close();
            }

            return(false);
        }
        /// <summary>
        /// Deletes an object from cache given cache key, a delete time, and an optional hashcode.
        ///
        /// The item is immediately made non retrievable.<br/>
        /// Keep in mind:
        /// <see cref="add">add(string, object)</see> and <see cref="replace">replace(string, object)</see>
        ///	will fail when used with the same key will fail, until the server reaches the
        ///	specified time. However, <see cref="set">set(string, object)</see> will succeed
        /// and the new value will not be deleted.
        /// </summary>
        /// <param name="key">the key to be removed</param>
        /// <param name="hashCode">if not null, then the int hashcode to use</param>
        /// <param name="expiry">when to expire the record.</param>
        /// <returns><c>true</c>, if the data was deleted successfully</returns>
        public bool Delete(string key, object hashCode, DateTime expiry)
        {
            if (key == null)
            {
                return(false);
            }
            key = Prefix + key;

            // get SockIO obj from hash or from key
            SockIO sock = SockIOPool.GetInstance(_poolName).GetSock(key, hashCode);

            // return false if unable to get SockIO obj
            if (sock == null)
            {
                return(false);
            }

            // build command
            StringBuilder command = new StringBuilder("delete ").Append(key);

            if (expiry != DateTime.MaxValue)
            {
                command.Append(" " + GetExpirationTime(expiry) / 1000);
            }

            command.Append("\r\n");

            try
            {
                sock.Write(Encoding.UTF8.GetBytes(command.ToString()));
                sock.Flush();

                // if we get appropriate response back, then we return true
                string line = sock.ReadLine();
                if (DELETED == line)
                {
                    // return sock to pool and bail here
                    sock.Close();
                    sock = null;
                    return(true);
                }
            }
            catch
            {
                try
                {
                    if (sock != null)
                    {
                        sock.TrueClose();
                    }
                }
                finally
                {
                    sock = null;
                }
            }
            if (sock != null)
            {
                sock.Close();
            }

            return(false);
        }
        /// <summary>
        /// Retrieves stats for passed in servers (or all servers).
        ///
        /// Returns a map keyed on the servername.
        /// The value is another map which contains stats
        /// with stat name as key and value as value.
        /// </summary>
        /// <param name="servers">string array of servers to retrieve stats from, or all if this is null</param>
        /// <returns>Stats map</returns>
        public Hashtable Stats(ArrayList servers)
        {
            // get SockIOPool instance
            SockIOPool pool = SockIOPool.GetInstance(_poolName);

            // return false if unable to get SockIO obj
            if (pool == null)
            {
                return(null);
            }

            // get all servers and iterate over them
            if (servers == null)
            {
                servers = pool.Servers;
            }

            // if no servers, then return early
            if (servers == null || servers.Count <= 0)
            {
                return(null);
            }

            // array of stats Hashtables
            Hashtable statsMaps = new Hashtable();

            for (int i = 0; i < servers.Count; i++)
            {
                SockIO sock = pool.GetConnection((string)servers[i]);
                if (sock == null)
                {
                    continue;
                }

                // build command
                string command = "stats\r\n";

                try
                {
                    sock.Write(UTF8Encoding.UTF8.GetBytes(command));
                    sock.Flush();

                    // map to hold key value pairs
                    Hashtable stats = new Hashtable();

                    // loop over results
                    while (true)
                    {
                        string line = sock.ReadLine();

                        if (line.StartsWith(STATS))
                        {
                            string[] info = line.Split(' ');
                            string   key  = info[1];
                            string   val  = info[2];

                            stats[key] = val;
                        }
                        else if (END == line)
                        {
                            break;
                        }

                        statsMaps[servers[i]] = stats;
                    }
                }
                catch (IOException e)
                {
                    try
                    {
                        sock.TrueClose();
                    }
                    catch (IOException)
                    {
                    }

                    sock = null;
                }

                if (sock != null)
                {
                    sock.Close();
                }
            }

            return(statsMaps);
        }
        /// <summary>
        /// Invalidates the entire cache.
        ///
        /// Will return true only if succeeds in clearing all servers.
        /// If pass in null, then will try to flush all servers.
        /// </summary>
        /// <param name="servers">optional array of host(s) to flush (host:port)</param>
        /// <returns>success true/false</returns>
        public bool FlushAll(ArrayList servers)
        {
            // get SockIOPool instance
            SockIOPool pool = SockIOPool.GetInstance(_poolName);

            // return false if unable to get SockIO obj
            if (pool == null)
            {
                return(false);
            }

            // get all servers and iterate over them
            if (servers == null)
            {
                servers = pool.Servers;
            }

            // if no servers, then return early
            if (servers == null || servers.Count <= 0)
            {
                return(false);
            }

            bool success = true;

            for (int i = 0; i < servers.Count; i++)
            {
                SockIO sock = pool.GetConnection((string)servers[i]);
                if (sock == null)
                {
                    success = false;
                    continue;
                }

                // build command
                string command = "flush_all\r\n";

                try
                {
                    sock.Write(Encoding.UTF8.GetBytes(command));
                    sock.Flush();

                    // if we get appropriate response back, then we return true
                    string line = sock.ReadLine();
                    success = (OK == line)
                                                ? success && true
                                                : false;
                }
                catch (IOException e)
                {
                    try
                    {
                        sock.TrueClose();
                    }
                    catch {}

                    success = false;
                    sock    = null;
                }

                if (sock != null)
                {
                    sock.Close();
                }
            }

            return(success);
        }
        /// <summary>
        /// This method loads the data from cache into a Hashtable.
        ///
        /// Pass a SockIO object which is ready to receive data and a Hashtable
        /// to store the results.
        /// </summary>
        /// <param name="sock">socket waiting to pass back data</param>
        /// <param name="hm">hashmap to store data into</param>
        /// <param name="asString">if true, and if we are using NativehHandler, return string val</param>
        private void LoadItems(SockIO sock, Hashtable hm, bool asString)
        {
            while (true)
            {
                string line = sock.ReadLine();

                if (line.StartsWith(VALUE))
                {
                    string[] info   = line.Split(' ');
                    string   key    = info[1];
                    int      flag   = int.Parse(info[2], new NumberFormatInfo());
                    int      length = int.Parse(info[3], new NumberFormatInfo());

                    // read obj into buffer
                    byte[] buf = new byte[length];
                    sock.Read(buf);
                    sock.ClearEndOfLine();

                    // ready object
                    object o = null;

                    // check for compression
                    if ((flag & F_COMPRESSED) != 0)
                    {
                        MemoryStream mem = null;
                        GZipStream   gzi = null;
                        try
                        {
                            // read the input stream, and write to a byte array output stream since
                            // we have to read into a byte array, but we don't know how large it
                            // will need to be, and we don't want to resize it a bunch
                            mem = new MemoryStream(buf.Length);
                            gzi = new GZipStream(new MemoryStream(buf), CompressionMode.Compress);

                            int count;
                            var tmp = new byte[2048];
                            while ((count = gzi.Read(tmp, 0, tmp.Length)) > 0)
                            {
                                mem.Write(tmp, 0, count);
                            }

                            // store uncompressed back to buffer
                            buf = mem.ToArray();
                        }
                        finally
                        {
                            if (mem != null)
                            {
                                mem.Close();
                                mem.Dispose();
                            }
                            if (gzi != null)
                            {
                                gzi.Close();
                                gzi.Dispose();
                            }
                        }
                    }

                    // we can only take out serialized objects
                    if ((flag & F_SERIALIZED) == 0)
                    {
                        if (_primitiveAsString || asString)
                        {
                            o = Encoding.GetEncoding(_defaultEncoding).GetString(buf);
                        }
                        else
                        {
                            // decoding object
                            try
                            {
                                o = NativeHandler.Decode(buf);
                            }
                            catch (Exception e)
                            {
                                return;
                            }
                        }
                    }
                    else
                    {
                        // deserialize if the data is serialized
                        MemoryStream memStream = null;
                        try
                        {
                            memStream = new MemoryStream(buf);
                            o         = new BinaryFormatter().Deserialize(memStream);
                        }
                        catch (SerializationException e)
                        {
                        }
                        finally
                        {
                            if (memStream != null)
                            {
                                memStream.Close();
                                memStream.Dispose();
                            }
                        }
                    }

                    // store the object into the cache
                    hm[key] = o;
                }
                else if (END == line)
                {
                    break;
                }
            }
        }