// Copyright (c) Service Stack LLC. All Rights Reserved.

// License: https://raw.github.com/ServiceStack/ServiceStack/master/license.txt

using System;

using ServiceStack.Logging;

using ServiceStack.Redis;

using ServiceStack.Web;

namespace ServiceStack

{

public class RedisErrorLoggerFeature : IPlugin

{

public static ILog Log = LogManager.GetLogger(typeof(RedisErrorLoggerFeature));

public IRedisClientsManager redisManager;

public RedisErrorLoggerFeature(IRedisClientsManager redisManager)

{

if (redisManager == null)

throw new ArgumentNullException("redisManager");

this.redisManager = redisManager;

}

public void Register(IAppHost appHost)

{

appHost.ServiceExceptionHandlers.Add(HandleServiceException);

appHost.UncaughtExceptionHandlers.Add(HandleUncaughtException);

}

/// <summary>

/// Service error logs are kept in 'urn:ServiceErrors:{ServiceName}'

/// </summary>

public const string UrnServiceErrorType = "ServiceErrors";

/// <summary>

/// Combined service error logs are maintained in 'urn:ServiceErrors:All'

/// </summary>

public const string CombinedServiceLogId = "All";

public void HandleUncaughtException(IRequest httpReq, IResponse httpRes, string operationName, Exception ex)

{

LogErrorInRedis(operationName, ex);

}

public object HandleServiceException(IRequest httpReq, object request, Exception ex)

{

LogErrorInRedis(httpReq.OperationName, ex);

return null;

}

private void LogErrorInRedis(string operationName, Exception ex)

{

try

{

//Get a thread-safe redis client from the client manager pool

using (var client = redisManager.GetClient())

{

//Get a client with a native interface for storing 'ResponseStatus' objects

var redis = client.As<ResponseStatus>();

//Store the errors in predictable Redis-named lists i.e.

//'urn:ServiceErrors:{ServiceName}' and 'urn:ServiceErrors:All'

var redisSeriviceErrorList = redis.Lists[UrnId.Create(UrnServiceErrorType, operationName)];

var redisCombinedErrorList = redis.Lists[UrnId.Create(UrnServiceErrorType, CombinedServiceLogId)];

//Append the error at the start of the service-specific and combined error logs.

var responseStatus = ex.ToResponseStatus();

redisSeriviceErrorList.Prepend(responseStatus);

redisCombinedErrorList.Prepend(responseStatus);

//Clip old error logs from the managed logs

const int rollingErrorCount = 1000;

redisSeriviceErrorList.Trim(0, rollingErrorCount);

redisCombinedErrorList.Trim(0, rollingErrorCount);

}

}

catch (Exception suppressRedisException)

{

Log.Error("Could not append exception to redis service error logs", suppressRedisException);

}

}

}

}