internal async Task <Document> DeleteHelperAsync(Key key, DeleteItemOperationConfig config, CancellationToken cancellationToken)
{
var currentConfig = config ?? new DeleteItemOperationConfig();
var req = new DeleteItemRequest
{
TableName = TableName,
Key = key
};
this.AddRequestHandler(req, isAsync: true);
if (currentConfig.ReturnValues == ReturnValues.AllOldAttributes)
{
req.ReturnValues = EnumMapper.Convert(currentConfig.ReturnValues);
}
ValidateConditional(currentConfig);
if (currentConfig.Expected != null)
{
req.Expected = this.ToExpectedAttributeMap(currentConfig.Expected);
}
else if (currentConfig.ExpectedState != null &&
currentConfig.ExpectedState.ExpectedValues != null &&
currentConfig.ExpectedState.ExpectedValues.Count > 0)
{
req.Expected = currentConfig.ExpectedState.ToExpectedAttributeMap(this);
if (req.Expected.Count > 1)
{
req.ConditionalOperator = EnumMapper.Convert(currentConfig.ExpectedState.ConditionalOperator);
}
}
else if (currentConfig.ConditionalExpression != null && currentConfig.ConditionalExpression.IsSet)
{
currentConfig.ConditionalExpression.ApplyExpression(req, this);
}
var attributes = (await DDBClient.DeleteItemAsync(req, cancellationToken).ConfigureAwait(false)).Attributes;
Document ret = null;
if (currentConfig.ReturnValues == ReturnValues.AllOldAttributes)
{
ret = this.FromAttributeMap(attributes);
}
return(ret);
}
public async Task <APIGatewayProxyResponse> OnDisconnectHandler(APIGatewayProxyRequest request, ILambdaContext context)
{
try
{
var connectionId = request.RequestContext.ConnectionId;
context.Logger.LogLine($"ConnectionId: {connectionId}");
var ddbRequest = new DeleteItemRequest
{
TableName = ConnectionMappingTable,
Key = new Dictionary <string, AttributeValue>
{
{ ConnectionIdField, new AttributeValue {
S = connectionId
} }
}
};
await DDBClient.DeleteItemAsync(ddbRequest);
return(new APIGatewayProxyResponse
{
StatusCode = 200,
Body = "Disconnected."
});
}
catch (Exception e)
{
context.Logger.LogLine("Error disconnecting: " + e.Message);
context.Logger.LogLine(e.StackTrace);
return(new APIGatewayProxyResponse
{
StatusCode = 500,
Body = $"Failed to disconnect: {e.Message}"
});
}
}
public async Task <APIGatewayProxyResponse> SendMessageHandler(APIGatewayProxyRequest request, ILambdaContext context)
{
try
{
// Construct the API Gateway endpoint that incoming message will be broadcasted to.
var domainName = request.RequestContext.DomainName;
var stage = request.RequestContext.Stage;
var endpoint = $"https://{domainName}/{stage}";
context.Logger.LogLine($"API Gateway management endpoint: {endpoint}");
// The body will look something like this: {"message":"sendmessage", "data":"What are you doing?"}
JsonDocument message = JsonDocument.Parse(request.Body);
// Grab the data from the JSON body which is the message to broadcasted.
JsonElement dataProperty;
if (!message.RootElement.TryGetProperty("data", out dataProperty))
{
context.Logger.LogLine("Failed to find data element in JSON document");
return(new APIGatewayProxyResponse
{
StatusCode = (int)HttpStatusCode.BadRequest
});
}
var data = dataProperty.GetString();
var stream = new MemoryStream(UTF8Encoding.UTF8.GetBytes(data));
// List all of the current connections. In a more advanced use case the table could be used to grab a group of connection ids for a chat group.
var scanRequest = new ScanRequest
{
TableName = ConnectionMappingTable,
ProjectionExpression = ConnectionIdField
};
var scanResponse = await DDBClient.ScanAsync(scanRequest);
// Construct the IAmazonApiGatewayManagementApi which will be used to send the message to.
var apiClient = ApiGatewayManagementApiClientFactory(endpoint);
// Loop through all of the connections and broadcast the message out to the connections.
var count = 0;
foreach (var item in scanResponse.Items)
{
var postConnectionRequest = new PostToConnectionRequest
{
ConnectionId = item[ConnectionIdField].S,
Data = stream
};
try
{
context.Logger.LogLine($"Post to connection {count}: {postConnectionRequest.ConnectionId}");
stream.Position = 0;
await apiClient.PostToConnectionAsync(postConnectionRequest);
count++;
}
catch (AmazonServiceException e)
{
// API Gateway returns a status of 410 GONE then the connection is no
// longer available. If this happens, delete the identifier
// from our DynamoDB table.
if (e.StatusCode == HttpStatusCode.Gone)
{
var ddbDeleteRequest = new DeleteItemRequest
{
TableName = ConnectionMappingTable,
Key = new Dictionary <string, AttributeValue>
{
{ ConnectionIdField, new AttributeValue {
S = postConnectionRequest.ConnectionId
} }
}
};
context.Logger.LogLine($"Deleting gone connection: {postConnectionRequest.ConnectionId}");
await DDBClient.DeleteItemAsync(ddbDeleteRequest);
}
else
{
context.Logger.LogLine($"Error posting message to {postConnectionRequest.ConnectionId}: {e.Message}");
context.Logger.LogLine(e.StackTrace);
}
}
}
return(new APIGatewayProxyResponse
{
StatusCode = (int)HttpStatusCode.OK,
Body = "Data sent to " + count + " connection" + (count == 1 ? "" : "s")
});
}
catch (Exception e)
{
context.Logger.LogLine("Error disconnecting: " + e.Message);
context.Logger.LogLine(e.StackTrace);
return(new APIGatewayProxyResponse
{
StatusCode = (int)HttpStatusCode.InternalServerError,
Body = $"Failed to send message: {e.Message}"
});
}
}
public async Task <APIGatewayProxyResponse> SendMessageHandler(APIGatewayProxyRequest request, ILambdaContext context)
{
try
{
// Construct the API Gateway endpoint that incoming message will be broadcasted to.
var domainName = request.RequestContext.DomainName;
var stage = request.RequestContext.Stage;
var endpoint = $"https://{domainName}/{stage}";
var connectionId = request.RequestContext.ConnectionId;
context.Logger.LogLine($"API Gateway management endpoint: {endpoint}");
JsonDocument message = JsonDocument.Parse(request.Body);
// Grab the data from the JSON body which is the message to broadcasted.
JsonElement dataProperty;
if (!message.RootElement.TryGetProperty("data", out dataProperty))
{
context.Logger.LogLine("Failed to find data element in JSON document");
return(new APIGatewayProxyResponse
{
StatusCode = (int)HttpStatusCode.BadRequest
});
}
var options = new JsonSerializerOptions
{
PropertyNameCaseInsensitive = true,
};
ChatMessageRequest messageRequest = JsonSerializer.Deserialize <ChatMessageRequest>(dataProperty.ToString(), options);
string date = (DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds.ToString();
await DDBUtils.PutMessage(messageRequest.Message, messageRequest.RoomID, messageRequest.UserID, date);
ChatMessageResponse chatMsg = new ChatMessageResponse
{
Success = true,
Message = messageRequest.Message,
Date = date,
Author = messageRequest.UserID,
RoomId = messageRequest.RoomID
};
string data = JsonSerializer.Serialize(chatMsg);
var stream = new MemoryStream(UTF8Encoding.UTF8.GetBytes(data));
var queryRequest = new QueryRequest
{
TableName = RoomsConnectionsTable,
KeyConditionExpression = "RoomId = :ri",
ExpressionAttributeValues = new Dictionary <string, AttributeValue> {
{ ":ri", new AttributeValue {
S = messageRequest.RoomID
} }
},
ProjectionExpression = "RoomId, ConnectionId"
};
var queryResponse = await DDBClient.QueryAsync(queryRequest);
// Construct the IAmazonApiGatewayManagementApi which will be used to send the message to.
var apiClient = ApiGatewayManagementApiClientFactory(endpoint);
// Loop through all of the connections and broadcast the message out to the connections.
var count = 0;
foreach (var item in queryResponse.Items)
{
var postConnectionRequest = new PostToConnectionRequest
{
ConnectionId = item["ConnectionId"].S,
Data = stream
};
try
{
context.Logger.LogLine($"Post to connection {count}: {postConnectionRequest.ConnectionId}");
stream.Position = 0;
await apiClient.PostToConnectionAsync(postConnectionRequest);
count++;
}
catch (AmazonServiceException e)
{
// API Gateway returns a status of 410 GONE then the connection is no
// longer available. If this happens, delete the identifier
// from our DynamoDB table.
if (e.StatusCode == HttpStatusCode.Gone)
{
var ddbDeleteRequest = new DeleteItemRequest
{
TableName = RoomsConnectionsTable,
Key = new Dictionary <string, AttributeValue>
{
{ "RoomId", new AttributeValue {
S = item["RoomId"].S
} },
{ "ConnectionId", new AttributeValue {
S = postConnectionRequest.ConnectionId
} }
}
};
context.Logger.LogLine($"Deleting gone connection: {postConnectionRequest.ConnectionId}");
await DDBClient.DeleteItemAsync(ddbDeleteRequest);
}
else
{
context.Logger.LogLine($"Error posting message to {postConnectionRequest.ConnectionId}: {e.Message}");
context.Logger.LogLine(e.StackTrace);
}
}
}
return(new APIGatewayProxyResponse
{
StatusCode = (int)HttpStatusCode.OK,
Body = "Data sent to " + count + " connection" + (count == 1 ? "" : "s")
});
}
catch (Exception e)
{
context.Logger.LogLine("Error sending message: " + e.Message);
context.Logger.LogLine(e.StackTrace);
return(new APIGatewayProxyResponse
{
StatusCode = (int)HttpStatusCode.InternalServerError,
Body = $"Failed to send message: {e.Message}"
});
}
}
