public void Configure(
IApplicationBuilder app,
IWebHostEnvironment env,
WebAppAndElmAppConfig webAppAndElmAppConfig,
Func <DateTimeOffset> getDateTimeOffset)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
if (webAppAndElmAppConfig == null)
{
throw new Exception("Missing reference to the web app config.");
}
var nextHttpRequestIndex = 0;
if (webAppAndElmAppConfig.WebAppConfiguration.JsonStructure?.letsEncryptOptions != null)
{
app.UseFluffySpoonLetsEncryptChallengeApprovalMiddleware();
}
var createVolatileHostAttempts = 0;
var volatileHosts = new ConcurrentDictionary <string, VolatileHost>();
InterfaceToHost.Result <InterfaceToHost.TaskResult.RequestToVolatileHostError, InterfaceToHost.TaskResult.RequestToVolatileHostComplete>
performProcessTaskRequestToVolatileHost(
InterfaceToHost.Task.RequestToVolatileHostStructure requestToVolatileHost)
{
if (!volatileHosts.TryGetValue(requestToVolatileHost.hostId, out var volatileHost))
{
return(new InterfaceToHost.Result <InterfaceToHost.TaskResult.RequestToVolatileHostError, InterfaceToHost.TaskResult.RequestToVolatileHostComplete>
{
Err = new InterfaceToHost.TaskResult.RequestToVolatileHostError
{
HostNotFound = new object(),
}
});
}
var stopwatch = System.Diagnostics.Stopwatch.StartNew();
var fromVolatileHostResult = volatileHost.ProcessRequest(requestToVolatileHost.request);
stopwatch.Stop();
return(new InterfaceToHost.Result <InterfaceToHost.TaskResult.RequestToVolatileHostError, InterfaceToHost.TaskResult.RequestToVolatileHostComplete>
{
Ok = new InterfaceToHost.TaskResult.RequestToVolatileHostComplete
{
exceptionToString = fromVolatileHostResult.Exception?.ToString(),
returnValueToString = fromVolatileHostResult.ReturnValue?.ToString(),
durationInMilliseconds = stopwatch.ElapsedMilliseconds,
}
});
}
InterfaceToHost.TaskResult performProcessTask(InterfaceToHost.Task task)
{
if (task?.CreateVolatileHost != null)
{
try
{
var volatileHost = new VolatileHost(BlobLibrary.GetBlobWithSHA256, task?.CreateVolatileHost.script);
var volatileHostId = System.Threading.Interlocked.Increment(ref createVolatileHostAttempts).ToString();
volatileHosts[volatileHostId] = volatileHost;
return(new InterfaceToHost.TaskResult
{
CreateVolatileHostResponse = new InterfaceToHost.Result <InterfaceToHost.TaskResult.CreateVolatileHostErrorStructure, InterfaceToHost.TaskResult.CreateVolatileHostComplete>
{
Ok = new InterfaceToHost.TaskResult.CreateVolatileHostComplete
{
hostId = volatileHostId,
},
},
});
}
catch (Exception createVolatileHostException)
{
return(new InterfaceToHost.TaskResult
{
CreateVolatileHostResponse = new InterfaceToHost.Result <InterfaceToHost.TaskResult.CreateVolatileHostErrorStructure, InterfaceToHost.TaskResult.CreateVolatileHostComplete>
{
Err = new InterfaceToHost.TaskResult.CreateVolatileHostErrorStructure
{
exceptionToString = createVolatileHostException.ToString(),
},
},
});
}
}
if (task?.ReleaseVolatileHost != null)
{
volatileHosts.TryRemove(task?.ReleaseVolatileHost.hostId, out var volatileHost);
return(new InterfaceToHost.TaskResult
{
CompleteWithoutResult = new object(),
});
}
if (task?.RequestToVolatileHost != null)
{
return(new InterfaceToHost.TaskResult
{
RequestToVolatileHostResponse = performProcessTaskRequestToVolatileHost(task?.RequestToVolatileHost),
});
}
throw new NotImplementedException("Unexpected task structure.");
}
void performProcessTaskAndFeedbackEvent(InterfaceToHost.StartTask taskWithId)
{
var taskResult = performProcessTask(taskWithId.task);
var interfaceEvent = new InterfaceToHost.Event
{
taskComplete = new InterfaceToHost.ResultFromTaskWithId
{
taskId = taskWithId.taskId,
taskResult = taskResult,
}
};
processEventAndResultingRequests(interfaceEvent);
}
var processRequestCompleteHttpResponse = new ConcurrentDictionary <string, InterfaceToHost.HttpResponse>();
void processEventAndResultingRequests(InterfaceToHost.Event interfaceEvent)
{
var serializedInterfaceEvent = Newtonsoft.Json.JsonConvert.SerializeObject(interfaceEvent, jsonSerializerSettings);
var serializedResponse = webAppAndElmAppConfig.ProcessEventInElmApp(serializedInterfaceEvent);
InterfaceToHost.ResponseOverSerialInterface structuredResponse = null;
try
{
structuredResponse =
Newtonsoft.Json.JsonConvert.DeserializeObject <InterfaceToHost.ResponseOverSerialInterface>(
serializedResponse);
}
catch (Exception parseException)
{
throw new Exception(
"Failed to parse event response from app. Looks like the loaded elm app is not compatible with the interface.\nResponse from app follows:\n" + serializedResponse,
parseException);
}
if (structuredResponse?.decodeEventSuccess == null)
{
throw new Exception("Hosted app failed to decode the event: " + structuredResponse.decodeEventError);
}
foreach (var requestFromProcess in structuredResponse.decodeEventSuccess)
{
if (requestFromProcess.completeHttpResponse != null)
{
processRequestCompleteHttpResponse[requestFromProcess.completeHttpResponse.httpRequestId] =
requestFromProcess.completeHttpResponse.response;
}
if (requestFromProcess.startTask != null)
{
System.Threading.Tasks.Task.Run(() => performProcessTaskAndFeedbackEvent(requestFromProcess.startTask));
}
}
}
app
.Use(async(context, next) => await Asp.MiddlewareFromWebAppConfig(webAppAndElmAppConfig.WebAppConfiguration, context, next))
.Run(async(context) =>
{
var currentDateTime = getDateTimeOffset();
var timeMilli = currentDateTime.ToUnixTimeMilliseconds();
var httpRequestIndex = System.Threading.Interlocked.Increment(ref nextHttpRequestIndex);
var httpRequestId = timeMilli.ToString() + "-" + httpRequestIndex.ToString();
{
var httpEvent = AsPersistentProcessInterfaceHttpRequestEvent(context, httpRequestId, currentDateTime);
var httpRequestInterfaceEvent = new InterfaceToHost.Event
{
httpRequest = httpEvent,
};
processEventAndResultingRequests(httpRequestInterfaceEvent);
}
var waitForHttpResponseClock = System.Diagnostics.Stopwatch.StartNew();
while (true)
{
if (processRequestCompleteHttpResponse.TryRemove(httpRequestId, out var httpResponse))
{
var headerContentType =
httpResponse.headersToAdd
?.FirstOrDefault(header => header.name?.ToLowerInvariant() == "content-type")
?.values?.FirstOrDefault();
context.Response.StatusCode = httpResponse.statusCode;
foreach (var headerToAdd in (httpResponse.headersToAdd).EmptyIfNull())
{
context.Response.Headers[headerToAdd.name] =
new Microsoft.Extensions.Primitives.StringValues(headerToAdd.values);
}
if (headerContentType != null)
{
context.Response.ContentType = headerContentType;
}
await context.Response.WriteAsync(httpResponse?.bodyAsString ?? "");
break;
}
if (60 <= waitForHttpResponseClock.Elapsed.TotalSeconds)
{
throw new TimeoutException(
"Persistent process did not return a HTTP response within " +
(int)waitForHttpResponseClock.Elapsed.TotalSeconds +
" seconds.");
}
System.Threading.Thread.Sleep(100);
}
});
}
public void Configure(
IApplicationBuilder app,
IWebHostEnvironment env,
WebAppAndElmAppConfig webAppAndElmAppConfig,
Func <DateTimeOffset> getDateTimeOffset,
IHostApplicationLifetime appLifetime)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
if (webAppAndElmAppConfig == null)
{
throw new Exception("Missing reference to the web app config.");
}
var applicationStoppingCancellationTokenSource = new System.Threading.CancellationTokenSource();
appLifetime.ApplicationStopping.Register(() =>
{
applicationStoppingCancellationTokenSource.Cancel();
_logger?.LogInformation("Public app noticed ApplicationStopping.");
});
var nextHttpRequestIndex = 0;
if (webAppAndElmAppConfig.WebAppConfiguration?.letsEncryptOptions != null)
{
app.UseFluffySpoonLetsEncryptChallengeApprovalMiddleware();
}
var createVolatileHostAttempts = 0;
var volatileHosts = new ConcurrentDictionary <string, VolatileHost>();
var appTaskCompleteHttpResponse = new ConcurrentDictionary <string, InterfaceToHost.HttpResponse>();
System.Threading.Timer notifyTimeHasArrivedTimer = null;
DateTimeOffset? lastAppEventTimeHasArrived = null;
InterfaceToHost.NotifyWhenArrivedAtTimeRequestStructure nextTimeToNotify = null;
var nextTimeToNotifyLock = new object();
InterfaceToHost.Result <InterfaceToHost.TaskResult.RequestToVolatileHostError, InterfaceToHost.TaskResult.RequestToVolatileHostComplete>
performProcessTaskRequestToVolatileHost(
InterfaceToHost.Task.RequestToVolatileHostStructure requestToVolatileHost)
{
if (!volatileHosts.TryGetValue(requestToVolatileHost.hostId, out var volatileHost))
{
return(new InterfaceToHost.Result <InterfaceToHost.TaskResult.RequestToVolatileHostError, InterfaceToHost.TaskResult.RequestToVolatileHostComplete>
{
Err = new InterfaceToHost.TaskResult.RequestToVolatileHostError
{
HostNotFound = new object(),
}
});
}
var stopwatch = System.Diagnostics.Stopwatch.StartNew();
var fromVolatileHostResult = volatileHost.ProcessRequest(requestToVolatileHost.request);
stopwatch.Stop();
return(new InterfaceToHost.Result <InterfaceToHost.TaskResult.RequestToVolatileHostError, InterfaceToHost.TaskResult.RequestToVolatileHostComplete>
{
Ok = new InterfaceToHost.TaskResult.RequestToVolatileHostComplete
{
exceptionToString = fromVolatileHostResult.Exception?.ToString(),
returnValueToString = fromVolatileHostResult.ReturnValue?.ToString(),
durationInMilliseconds = stopwatch.ElapsedMilliseconds,
}
});
}
InterfaceToHost.TaskResult performProcessTask(InterfaceToHost.Task task)
{
if (task?.CreateVolatileHost != null)
{
try
{
var volatileHost = new VolatileHost(BlobLibrary.GetBlobWithSHA256, task?.CreateVolatileHost.script);
var volatileHostId = System.Threading.Interlocked.Increment(ref createVolatileHostAttempts).ToString();
volatileHosts[volatileHostId] = volatileHost;
return(new InterfaceToHost.TaskResult
{
CreateVolatileHostResponse = new InterfaceToHost.Result <InterfaceToHost.TaskResult.CreateVolatileHostErrorStructure, InterfaceToHost.TaskResult.CreateVolatileHostComplete>
{
Ok = new InterfaceToHost.TaskResult.CreateVolatileHostComplete
{
hostId = volatileHostId,
},
},
});
}
catch (Exception createVolatileHostException)
{
return(new InterfaceToHost.TaskResult
{
CreateVolatileHostResponse = new InterfaceToHost.Result <InterfaceToHost.TaskResult.CreateVolatileHostErrorStructure, InterfaceToHost.TaskResult.CreateVolatileHostComplete>
{
Err = new InterfaceToHost.TaskResult.CreateVolatileHostErrorStructure
{
exceptionToString = createVolatileHostException.ToString(),
},
},
});
}
}
if (task?.ReleaseVolatileHost != null)
{
volatileHosts.TryRemove(task?.ReleaseVolatileHost.hostId, out var volatileHost);
return(new InterfaceToHost.TaskResult
{
CompleteWithoutResult = new object(),
});
}
if (task?.RequestToVolatileHost != null)
{
return(new InterfaceToHost.TaskResult
{
RequestToVolatileHostResponse = performProcessTaskRequestToVolatileHost(task?.RequestToVolatileHost),
});
}
throw new NotImplementedException("Unexpected task structure.");
}
void performProcessTaskAndFeedbackEvent(InterfaceToHost.StartTask taskWithId)
{
var taskResult = performProcessTask(taskWithId.task);
var interfaceEvent = new InterfaceToHost.AppEventStructure
{
TaskCompleteEvent = new InterfaceToHost.ResultFromTaskWithId
{
taskId = taskWithId.taskId,
taskResult = taskResult,
}
};
processEventAndResultingRequests(interfaceEvent);
}
void processEventAndResultingRequests(InterfaceToHost.AppEventStructure interfaceEvent)
{
var prepareProcessEvent = prepareProcessEventAndResultingRequests(interfaceEvent);
prepareProcessEvent.processEventAndResultingRequests();
}
(string serializedInterfaceEvent, Action processEventAndResultingRequests) prepareProcessEventAndResultingRequests(
InterfaceToHost.AppEventStructure interfaceEvent)
{
var serializedInterfaceEvent = Newtonsoft.Json.JsonConvert.SerializeObject(interfaceEvent, jsonSerializerSettings);
var processEvent = new Action(() =>
{
if (applicationStoppingCancellationTokenSource.IsCancellationRequested)
{
return;
}
string serializedResponse = null;
try
{
serializedResponse = webAppAndElmAppConfig.ProcessEventInElmApp(serializedInterfaceEvent);
}
catch (Exception) when(applicationStoppingCancellationTokenSource.IsCancellationRequested)
{
return;
}
InterfaceToHost.ResponseOverSerialInterface structuredResponse = null;
try
{
structuredResponse =
Newtonsoft.Json.JsonConvert.DeserializeObject <InterfaceToHost.ResponseOverSerialInterface>(
serializedResponse);
}
catch (Exception parseException)
{
throw new Exception(
"Failed to parse event response from app. Looks like the loaded elm app is not compatible with the interface.\nResponse from app follows:\n" + serializedResponse,
parseException);
}
if (structuredResponse?.DecodeEventSuccess == null)
{
throw new Exception("Hosted app failed to decode the event: " + structuredResponse.DecodeEventError);
}
if (structuredResponse.DecodeEventSuccess.notifyWhenArrivedAtTime != null)
{
System.Threading.Tasks.Task.Run(() =>
{
lock (nextTimeToNotifyLock)
{
nextTimeToNotify = structuredResponse.DecodeEventSuccess.notifyWhenArrivedAtTime;
}
});
}
foreach (var startTask in structuredResponse.DecodeEventSuccess.startTasks)
{
System.Threading.Tasks.Task.Run(() => performProcessTaskAndFeedbackEvent(startTask));
}
foreach (var completeHttpResponse in structuredResponse.DecodeEventSuccess.completeHttpResponses)
{
appTaskCompleteHttpResponse[completeHttpResponse.httpRequestId] =
completeHttpResponse.response;
}
});
return(serializedInterfaceEvent, processEvent);
}
void processEventTimeHasArrived()
{
var currentTime = getDateTimeOffset();
lastAppEventTimeHasArrived = currentTime;
processEventAndResultingRequests(new InterfaceToHost.AppEventStructure
{
ArrivedAtTimeEvent = new InterfaceToHost.ArrivedAtTimeEventStructure
{
posixTimeMilli = currentTime.ToUnixTimeMilliseconds()
}
});
}
notifyTimeHasArrivedTimer = new System.Threading.Timer(
callback: _ =>
{
if (applicationStoppingCancellationTokenSource.IsCancellationRequested)
{
notifyTimeHasArrivedTimer?.Dispose();
return;
}
lock (nextTimeToNotifyLock)
{
if (applicationStoppingCancellationTokenSource.IsCancellationRequested)
{
notifyTimeHasArrivedTimer?.Dispose();
return;
}
var localNextTimeToNotify = nextTimeToNotify;
if (localNextTimeToNotify != null && localNextTimeToNotify.posixTimeMilli <= getDateTimeOffset().ToUnixTimeMilliseconds())
{
nextTimeToNotify = null;
processEventTimeHasArrived();
return;
}
}
if (lastAppEventTimeHasArrived.HasValue
?
notifyTimeHasArrivedMaximumDistance <= (getDateTimeOffset() - lastAppEventTimeHasArrived.Value)
:
true)
{
processEventTimeHasArrived();
}
},
state: null,
dueTime: TimeSpan.Zero,
period: TimeSpan.FromMilliseconds(10));
processEventTimeHasArrived();
app
.Use(async(context, next) => await Asp.MiddlewareFromWebAppConfig(webAppAndElmAppConfig.WebAppConfiguration, context, next))
.Run(async(context) =>
{
var currentDateTime = getDateTimeOffset();
var timeMilli = currentDateTime.ToUnixTimeMilliseconds();
var httpRequestIndex = System.Threading.Interlocked.Increment(ref nextHttpRequestIndex);
var httpRequestId = timeMilli.ToString() + "-" + httpRequestIndex.ToString();
var httpRequestEvent =
await AsPersistentProcessInterfaceHttpRequestEvent(context, httpRequestId, currentDateTime);
var httpRequestInterfaceEvent = new InterfaceToHost.AppEventStructure
{
HttpRequestEvent = httpRequestEvent,
};
var preparedProcessEvent = prepareProcessEventAndResultingRequests(httpRequestInterfaceEvent);
if (webAppAndElmAppConfig.WebAppConfiguration?.httpRequestEventSizeLimit < preparedProcessEvent.serializedInterfaceEvent?.Length)
{
context.Response.StatusCode = StatusCodes.Status400BadRequest;
await context.Response.WriteAsync("Request is too large.");
return;
}
preparedProcessEvent.processEventAndResultingRequests();
var waitForHttpResponseClock = System.Diagnostics.Stopwatch.StartNew();
while (true)
{
if (appTaskCompleteHttpResponse.TryRemove(httpRequestId, out var httpResponse))
{
var headerContentType =
httpResponse.headersToAdd
?.FirstOrDefault(header => header.name?.ToLowerInvariant() == "content-type")
?.values?.FirstOrDefault();
context.Response.StatusCode = httpResponse.statusCode;
foreach (var headerToAdd in (httpResponse.headersToAdd).EmptyIfNull())
{
context.Response.Headers[headerToAdd.name] = new Microsoft.Extensions.Primitives.StringValues(headerToAdd.values);
}
if (headerContentType != null)
{
context.Response.ContentType = headerContentType;
}
byte[] contentAsByteArray = null;
if (httpResponse?.bodyAsBase64 != null)
{
var buffer = new byte[httpResponse.bodyAsBase64.Length * 3 / 4];
if (!Convert.TryFromBase64String(httpResponse.bodyAsBase64, buffer, out var bytesWritten))
{
throw new FormatException(
"Failed to convert from base64. bytesWritten=" + bytesWritten +
", input.length=" + httpResponse.bodyAsBase64.Length + ", input:\n" +
httpResponse.bodyAsBase64);
}
contentAsByteArray = buffer.AsSpan(0, bytesWritten).ToArray();
}
context.Response.ContentLength = contentAsByteArray?.Length ?? 0;
if (contentAsByteArray != null)
{
await context.Response.Body.WriteAsync(contentAsByteArray);
}
break;
}
if (60 <= waitForHttpResponseClock.Elapsed.TotalSeconds)
{
throw new TimeoutException(
"The app did not return a HTTP response within " +
(int)waitForHttpResponseClock.Elapsed.TotalSeconds +
" seconds.");
}
System.Threading.Thread.Sleep(100);
}
});
}