private static void WriteBulkString(Stream stream, RespValue value)
{
if (value.IsNull())
{
WriteNullable(stream, '$');
}
else
{
WriteBytes(stream, value, '$', true);
}
}
private static void WriteBytes(Stream stream, RespValue value, char header, bool withLength = false)
{
WriteHeader(stream, header);
var bytes = value.GetBytes();
if (withLength)
{
WriteInt(stream, bytes.Length);
WriteCrLf(stream);
}
WriteBytes(stream, bytes);
WriteCrLf(stream);
}
public RespValue Execute(IExecutionContext context, RespValue request)
{
try
{
EnsureArray(request);
var requestParts = request.GetItems();
EnsureNonEmptyArray(requestParts);
var commandPart = requestParts.First();
var argumentsPart = requestParts.Skip(1).ToArray();
var commandName = commandPart.GetString().ToUpperInvariant();
ICommand command;
if (!commandsMap.TryGetValue(commandName, out command))
{
return RespValue.Error(string.Format("ERR Unknown command '{0}'", commandName));
}
return command.Execute(context, argumentsPart);
}
catch (Exception)
{
return SharedContrants.UnknownError;
}
}
private static void WriteRespValue(Stream stream, RespValue respValue)
{
switch (respValue.Type)
{
case RespValueType.SimpleString:
WriteSimpleString(stream, respValue);
break;
case RespValueType.Error:
WriteErrorString(stream, respValue);
break;
case RespValueType.BulkString:
WriteBulkString(stream, respValue);
break;
case RespValueType.Array:
{
if (respValue.IsNull())
{
WriteNullable(stream, '*');
}
else
{
var respValues = respValue.GetItems();
WriteHeader(stream, '*');
WriteInt(stream, respValues.Length);
WriteCrLf(stream);
foreach (var item in respValues)
WriteRespValue(stream, item);
}
break;
}
case RespValueType.Integer:
{
WriteInteger(stream, respValue);
break;
}
default:
throw new ArgumentOutOfRangeException("respValue", respValue.Type.ToString());
}
}
private void EnsureNonEmptyArray(RespValue[] arguments)
{
if (arguments != null && arguments.Any())
return;
throw new Exception();
}
private void EnsureArray(RespValue request)
{
if (request.Type == RespValueType.Array)
return;
throw new Exception();
}
public bool TryPollRequest(out RespValue request)
{
request = null;
if (!Paused && socket.Poll(0, SelectMode.SelectRead))
{
var pollBufferFreeSpace = ResizeBufferAndGetFreeSpace(ref pollBuffer, pollBytes);
var receivedBytes = socket.Receive(pollBuffer, pollBytes, pollBufferFreeSpace, SocketFlags.None);
pollBytes += receivedBytes;
var respParseResult = RespParser.Parse(pollBuffer, 0, pollBytes);
if (respParseResult.Status == RespParseStatus.Success)
{
request = respParseResult.Value;
var valueBytes = respParseResult.ValueBytes;
var remainingBytes = pollBytes - valueBytes;
if (remainingBytes != 0)
{
Buffer.BlockCopy(pollBuffer, valueBytes, pollBuffer, 0, remainingBytes);
pollBytes = remainingBytes;
}
else
{
pollBytes = 0;
}
return true;
}
}
return false;
}
public void PushResponse(RespValue response)
{
var bytes = RespGenerator.Generate(response);
socket.Send(bytes);
}
public static RespValue Array(RespValue[] values)
{
return new RespValue(RespValueType.Array, values);
}
public static byte[] Generate(RespValue respValue)
{
var stream = new MemoryStream();
WriteRespValue(stream, respValue);
return stream.ToArray();
}
private static void WriteInteger(Stream stream, RespValue respValue)
{
WriteHeader(stream, ':');
WriteInt(stream, respValue.GetInt());
WriteCrLf(stream);
}
private static void WriteErrorString(Stream stream, RespValue value)
{
WriteBytes(stream, value, '-');
}
private static void WriteSimpleString(Stream stream, RespValue value)
{
WriteBytes(stream, value, '+');
}
