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How to have an AWS Lambda/Rekognition Function return an array of object keys

This feels like a simple question and I feel like I am overthinking it. I am doing an AWS project that will compare face(s) on an image to a database (s3bucket) of other faces. So far, I have a lambda function for the comparefacerequest, a class library which invokes the function, and an UWP that inputs the image file and outputs a result. It has worked so far being based on boolean (true or false) functions, but now I want it to instead return what face(s) are recognized via an array. I struggling at implementing this.
Below is my lambda function. I have adjusted the task to be an Array instead of a bool and changed the return to be an array. At the bottom, I have created a global variable class with a testing array so I could attempt to reference the array elsewhere.
public class Function
{
//Function
public async Task<Array> FunctionHandler(string input, ILambdaContext context)
{
//number of matched faces
int matched = 0;
//Client setup
var rekognitionclient = new AmazonRekognitionClient();
var s3client = new AmazonS3Client();
//Create list of target images
ListObjectsRequest list = new ListObjectsRequest
{
BucketName = "bucket2"
};
ListObjectsResponse listre = await s3client.ListObjectsAsync(list);
//loop of list
foreach (Amazon.S3.Model.S3Object obj in listre.S3Objects)
{
//face request with input and obj.key images
var comparefacesrequest = new CompareFacesRequest
{
SourceImage = new Image
{
S3Object = new S3Objects
{
Bucket = "bucket1",
Name = input
}
},
TargetImage = new Image
{
S3Object = new S3Objects
{
Bucket = "bucket2",
Name = obj.Key
}
},
};
//compare with confidence of 95 (subject to change) to current target image
var detectresponse = await rekognitionclient.CompareFacesAsync(comparefacesrequest);
detectresponse.FaceMatches.ForEach(match =>
{
ComparedFace face = match.Face;
if (match.Similarity > 95)
{
//if face detected, raise matched
matched++;
for(int i = 0; i < Globaltest.testingarray.Length; i++)
{
if (Globaltest.testingarray[i] == "test")
{
Globaltest.testingarray[i] = obj.Key;
}
}
}
});
}
//Return true or false depending on if it is matched
if (matched > 0)
{
return Globaltest.testingarray;
}
return Globaltest.testingarray;
}
}
public static class Globaltest
{
public static string[] testingarray = { "test", "test", "test" };
}
Next, is my invoke request in my class library. It has so far been based on the lambda outputting a boolean result, but I thought, "hey, it is parsing the result, it should be fine, right"? I do convert the result to a string, as there is no GetArray, from what I know.
public async Task<bool> IsFace(string filePath, string fileName)
{
await UploadS3(filePath, fileName);
AmazonLambdaClient client = new AmazonLambdaClient(accessKey, secretKey, Amazon.RegionEndpoint.USWest2);
InvokeRequest ir = new InvokeRequest();
ir.InvocationType = InvocationType.RequestResponse;
ir.FunctionName = "ImageTesting";
ir.Payload = "\"" + fileName + "\"";
var result = await client.InvokeAsync(ir);
var strResponse = Encoding.ASCII.GetString(result.Payload.ToArray());
if (bool.TryParse(strResponse, out bool result2))
{
return result2;
}
return false;
}
Finally, here is the section of my UWP where I perform the function. I am referencing the lambda client via "using Lambdaclienttest" (name of lamda project, and this is its only instance I use the reference though). When I run my project, I do still get a face detected when it should, but the Globaltest.testingarray[0] is still equal to "test".
var Facedetector = new FaceDetector(Credentials.accesskey, Credentials.secretkey);
try
{
var result = await Facedetector.IsFace(filepath, filename);
if (result)
{
textBox1.Text = "There is a face detected";
textBox2.Text = Globaltest.testingarray[0];
}
else
{
textBox1.Text = "Try Again";
}
}
catch
{
textBox1.Text = "Please use a photo";
}
Does anyone have any suggestions?

Step Over throws exception, but Step Into not Unity

I am making a unity game and have one strange situation, which I will try to explain.
Here is my UserCreator class in which I want to return nativeCountry from another class (MySQLCountryManager):
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Networking;
public class UserCreator : MonoBehaviour
{
public static PersonModel CreateUser(PersonModel model)
{
CountryModel nativeCountry = new CountryModel();
nativeCountry = MySQLCountryManager.GetCountryByName(model.NativeCountry);
<some other code here....>
}
}
And here is MySQLCountryManager class with GetCountryByName method:
using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using UnityEngine;
using UnityEngine.Networking;
public class MySQLCountryManager : MonoBehaviour
{
public static CountryModel GetCountryByName(string countryName)
{
CountryModel country = new CountryModel();
WWWForm form = new WWWForm();
form.AddField("CountryName", countryName);
UnityWebRequestAsyncOperation getCountryByName = new UnityWebRequestAsyncOperation();
getCountryByName = UnityWebRequest.Post(WebReguests.getCountryByName, form).SendWebRequest();
List<string> results = new List<string>();
if (getCountryByName.webRequest.isNetworkError || getCountryByName.webRequest.isHttpError)
{
Debug.LogError(getCountryByName.webRequest.error);
}
else
{
var data = getCountryByName.webRequest.downloadHandler.text;
string[] result = data.Split(',');
for (int i = 0; i < result.Length; i++)
{
results.Add(result[i]);
}
int id;
bool idOk;
idOk = int.TryParse(results[0], out id );
if (idOk)
{
country.id = id;
}
country.CountryName = results[1];
byte[] flagBytes = Convert.FromBase64String(results[2]);
country.Flag = flagBytes;
byte[] shapeBytes = Convert.FromBase64String(results[3]);
country.Shape = shapeBytes;
byte[] woP = Convert.FromBase64String(results[4]);
country.WorldPosition = woP;
byte[] coa = Convert.FromBase64String(results[5]);
country.CoatOfArms = coa;
byte[] dishPicBytes = Convert.FromBase64String(results[6]);
country.DishPic = dishPicBytes;
byte[] curiosityBytes = Convert.FromBase64String(results[7]);
country.CuriosityPic = curiosityBytes;
country.Continent = results[8];
country.Population = results[9];
country.Capital = results[10];
country.Language = results[11];
country.Currency = results[12];
country.Religion = results[13];
country.DishName = results[14];
}
return country;
}
Now, the problem is, when I start debugging project in Visual Studio 2019 if I go Step Into on native country in UserCreator and then Step Into in MySQLCountryManager.GetCountryById, code works fine and returns nativeCountry as I expect. But when I go Step Over nativeCountry, it always throws some exceptions, like 'Index was out of range', 'Input string is not in a correct format' etc. And this is happening for all methods with UnityWebRequest called from UserCreator class.
I tried to google for this but nothing useful was found.
Any idea why this is happening?

tl;dr: Sounds like a race condition to me!
While stepping into the method you most probably give the asynchronous request just enough time to actually finish in the background.
I don't see where you are waiting for the results of the asynchronous download.
See the examples of UnityWebRequest.Post => as with any other asynchronous execution you have to wait until the results are actually back.
Usually you would use a Coroutine with callback like e.g.
public static void GetCountryByNameAsync(MonoBehaviour caller, string countryName, Action<CountryModel> whenDone)
{
caller.StartCoroutine(GetCountryByNameRoutine(countryName, whenDone))
}
private static IEnumerator GetCountryByNameRoutine(string countryName, Action<CountryModel> whenDone)
{
var form = new WWWForm();
form.AddField("CountryName", countryName);
using(var request = UnityWebRequest.Post(WebReguests.getCountryByName, form))
{
// WAIT until the request has either failed or succeeded
yield return request.SendWebRequest();
if (request.isNetworkError || request.isHttpError)
{
Debug.LogError(request.error);
yield break;
}
var data = request.downloadHandler.text;
var results = data.Split(',');
var country = new CountryModel();
if (int.TryParse(results[0], out var id))
{
country.id = id;
}
country.CountryName = results[1];
var flagBytes = Convert.FromBase64String(results[2]);
country.Flag = flagBytes;
var shapeBytes = Convert.FromBase64String(results[3]);
country.Shape = shapeBytes;
var woP = Convert.FromBase64String(results[4]);
country.WorldPosition = woP;
var coa = Convert.FromBase64String(results[5]);
country.CoatOfArms = coa;
var dishPicBytes = Convert.FromBase64String(results[6]);
country.DishPic = dishPicBytes;
var curiosityBytes = Convert.FromBase64String(results[7]);
country.CuriosityPic = curiosityBytes;
country.Continent = results[8];
country.Population = results[9];
country.Capital = results[10];
country.Language = results[11];
country.Currency = results[12];
country.Religion = results[13];
country.DishName = results[14];
whenDone?.Invoke(country);
}
}
then later you would rather use it like e.g.
// caller will be whatever script is actually calling this method
// we will take that reference to make it also responsible for executing the according Coroutine
public static void CreateUserAsync(MonoBehaviour caller, PersonModel model, Action<PersonModel> whenDone)
{
MySQLCountryManager.GetCountryByName(caller, model.NativeCountry, nativeCountry =>
{
<some other code here....>
whenDone?.Invoke(theCreatedPersonModel);
});
}
Or if it gets more complex instead of Coroutines you might rather use an async - await approach and pass the final result back into the Unity main thread.

API is mixing up data from different devices

I have an API that has devices firing data to it at the same time or within a few milliseconds. What I am finding is that the data is getting mixed up. The data is sent every five minutes (on the clock 05, 10, 15 etc.) I have an execution filter that traps the URL data coming in so I always have a real source, then it goes to the endpoint and then onto processing. For example, there will a be random five minute period missing. When I debug step by step with the missing URL from the execution filter it works fine. By that I mean I take the URL and debug, then it inserts.
In summary, I have device id 1 and device id 2.I will get missing intervals even though, I can see the data has hit the execution filter.
I am assuming that the API is not handling these as separate transactions, but somehow mixing them up together, hence the data missing and the serial numbers appearing in the wrong place, such that data from id 1 is appearing in id 2 vice versa etc.
API End Point:
public class SomeController : ApiController
{
[HttpGet]
[ExecutionFilter]
public async Task<HttpResponseMessage> Get([FromUri] FixedDataModel fdm)
{
var reply = new HttpResponseMessage();
string url = HttpUtility.UrlDecode(HttpContext.Current.Request.QueryString.ToString());
if (url.Contains("timestamp"))
{
reply = TimeSyncValidation.TimeSync;
return reply;
}
else if (!url.Contains("timestamp"))
{
reply = await Task.Run(() => DeviceClass.DeviceApiAsync(fdm, url));
}
return reply;
}
}
Processing class:
namespace API.Services
{
public class DeviceClass
{
private static string serialNumber;
private static byte chk;
private static string channelName, channelReadingNumber, channelValue, queryString, readingDate;
private static int colonPosition, chanCountFrom, equalsPosition;
private static bool checkSumCorrect;
public static HttpResponseMessage DeviceApiAsync(FixedDataModel fdm, string urlQqueryString)
{
Guid guid = Guid.NewGuid();
//ExecutionTrackerHandler.Guid = guid;
//Remove question mark
var q = urlQqueryString;
queryString = q.Substring(0);
var items = HttpUtility.ParseQueryString(queryString);
serialNumber = items["se"];
//Store raw uri for fault finding
var rawUri = new List<RawUriModel>
{
new RawUriModel
{
UniqueId = guid,
RawUri = q,
TimeStamp = DateTime.Now
}
};
//Checksum validation
chk = Convert.ToByte(fdm.chk);
checkSumCorrect = CheckSumValidator.XorCheckSum(queryString, chk);
if (!checkSumCorrect)
{
return ValidationResponseMessage.ResponseHeaders("Checksum");
}
//Create list of items that exist in URL
var urldata = new UrlDataList
{
UrlData = queryString.Split('&').ToList(),
};
var data = new List<UriDataModel>();
//Split the URL string into its parts
foreach (var item in urldata.UrlData)
{
colonPosition = item.IndexOf(":");
chanCountFrom = colonPosition + 1;
equalsPosition = item.LastIndexOf("=");
if (colonPosition == -1)
{
channelName = item.Substring(0, equalsPosition);
channelReadingNumber = "";
channelValue = item.Substring(item.LastIndexOf("=") + 1);
}
else
{
channelName = item.Substring(0, colonPosition);
channelReadingNumber = item.Substring(chanCountFrom, equalsPosition - chanCountFrom);
channelValue = item.Substring(item.LastIndexOf("=") + 1);
if (channelName == "atime" || channelName == "adate")
{
readingDate = DateValidator.CreateDate(channelValue);
}
};
bool nullFlag = false;
if (channelValue == null)
nullFlag = true;
bool missingFlag = false;
if (channelValue == "x") {
missingFlag = true;
channelValue = "0";
}
//Add data to model ready for DB insert.
data.Add(new UriDataModel
{
uid = guid,
SerialNumber = serialNumber,
ChannelName = channelName,
ChannelReadingNumber = channelReadingNumber,
ChannelValue = channelValue.Replace(",", "."),
ReadingDate = readingDate,
TimeStamp = DateTime.Now.ToString("yyyy-MM-dd HH:mm"),
Processed = false,
NullFlag = nullFlag,
MissingFlag = missingFlag
});
};
//Validate dates
var allDates = (from x in data where x.ChannelName.Contains("atime") || x.ChannelName.Contains("adate") select x.ChannelValue).ToList();
bool dateValidation = DateValidator.IsValid(allDates);
if (!dateValidation)
{
return ValidationResponseMessage.ResponseHeaders("Date");
};
//Validate values
var channels = Enum.GetNames(typeof(Channels)).ToList();
List<string> allChannelValues = data.Where(d => channels.Contains(d.ChannelName)).Select(d => d.ChannelValue).ToList();
bool valueValidation = ValueValidator.IsValid(allChannelValues);
if (!valueValidation)
{
return ValidationResponseMessage.ResponseHeaders("Values");
};
//Insert live data
var insertData = DataInsert<UriDataModel>.InsertData(data, "Staging.UriData");
if (!insertData)
{
return ValidationResponseMessage.ResponseHeaders("Sql");
}
var content = "\r\nSUCCESS\r\n";
var reply = new HttpResponseMessage(System.Net.HttpStatusCode.OK)
{
Content = new StringContent(content)
};
return reply;
}
}
}
TIA

You are using global variables and static method to process your data.
Change your method to non-static.
Each DeviceClass worker must update only its own isolated data then push that off back to controller.

Cosmos DB Azure Table API oData Authentication REST / C#?

I'm trying to access Azure Cosmos DB using Table API.
The challenge is, despite creating SharedKeyLite, server is still returning Unauthorized - seems like SharedKeyLite is not supported or I'm generating the signature or headers wrong.
Here is the code
static readonly string storageAccountName = "accountName";
static readonly string storageAccountKey = "xxxx";
static readonly string uri = "https://accountName.table.cosmosdb.azure.com/Contacts()";
static readonly string utc_date = DateTime.UtcNow.ToString("r");
static void Main(string[] args)
{
Console.WriteLine(GetResult().Result);
}
static async Task<string> GetResult()
{
// Set this to whatever payload you desire. Ours is null because
// we're not passing anything in.
Byte[] requestPayload = null;
var requestDateString = DateTime.UtcNow.ToString("R", CultureInfo.InvariantCulture);
var requestUri = new Uri(uri);
DateTime now = DateTime.UtcNow;
//Instantiate the request message with a null payload.
using (var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, uri)
{ Content = (requestPayload == null) ? null : new ByteArrayContent(requestPayload) })
{
ConstructHeaders(httpRequestMessage.Headers, requestDateString);
string authorizationHeader = GenerateSharedKeyLite(storageAccountKey, storageAccountName, uri,requestDateString);
httpRequestMessage.Headers.Authorization = new AuthenticationHeaderValue("SharedKeyLite", authorizationHeader);
// Send the request.
using (HttpResponseMessage httpResponseMessage = await new HttpClient().SendAsync(httpRequestMessage))
{
string json = await httpResponseMessage.Content.ReadAsStringAsync();
return json;
}
}
}
These are the headers I"m adding, expansion of ConstructHeaders method.
Refer this link for request parameters
//Construct the headers
static void ConstructHeaders(HttpRequestHeaders headers, string now)
{
headers.Add("x-ms-date", now);
headers.Add("x-ms-version", "2017-04-17");
// If you need any additional headers, add them here before creating
// the authorization header.
headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
if (headers.Contains("DataServiceVersion"))
headers.Remove("DataServiceVersion");
headers.Add("DataServiceVersion", "3.0;NetFx");
if (headers.Contains("MaxDataServiceVersion"))
headers.Remove("MaxDataServiceVersion");
headers.Add("MaxDataServiceVersion", "3.0;NetFx");
}
And this is the method that creates the SharedKeyLite
//Created Shared Key Lite
static string GenerateSharedKeyLite(string accessKey, string account, string url, string date)
{
var uri = new Uri(url);
var canonicalizedResourceString = uri.PathAndQuery;
var queryStart = canonicalizedResourceString.IndexOf('?');
if (queryStart > -1)
{
if (queryStart < canonicalizedResourceString.Length - 1)
{
var path = canonicalizedResourceString.Substring(0, queryStart);
var parameters = HttpUtility.ParseQueryString(canonicalizedResourceString.Substring(queryStart + 1));
var sb = new StringBuilder();
foreach (var keyOri in parameters.Keys)
{
var value = parameters[keyOri];
var key = keyOri.ToLowerInvariant();
sb.Append("\n");
sb.Append(key);
sb.Append(":");
sb.Append(value);
}
canonicalizedResourceString = canonicalizedResourceString + sb.ToString();
}
else
{
canonicalizedResourceString = canonicalizedResourceString.Substring(0, canonicalizedResourceString.Length - 1);
}
}
canonicalizedResourceString = $"/{account}{canonicalizedResourceString}";
var stringToSign = $"{date}\n{canonicalizedResourceString}";
var signedSignature = string.Empty;
using (var hmac = new HMACSHA256(Convert.FromBase64String(accessKey)))
{
var outputBytes = hmac.ComputeHash(Encoding.UTF8.GetBytes(stringToSign));
var signature = Convert.ToBase64String(outputBytes);
return $"{account}:{signature}";
}
}
Any Help? Ideally I want to perform the odata query using simple.odata, but first trying to make this work using HttpClient

Just copy your code and it works on my side. If you haven't modified your code, please make sure your storageAccountName and storageAccountKey are correct.
BTW, in method GenerateSharedKeyLite there's no need to add query parameters to canonicalizedResourceString for entity operation. You only need to add comp if you want to operate component info for table or service. See constructing-the-canonicalized-resource-string.
The query string should include the question mark and the comp parameter (for example, ?comp=metadata). No other parameters should be included on the query string.

Unity C# GraphQL Post Request Body Authentication

I am working on trying to connect to my GraphQL server my developers have setup from within Unity. I have found some scripts to help with this process, however, I am still not able to connect because i need to be logged into the system hosting graphql to be able to query externally, I cannot just use the endpoint url.
My developer has told me to do a POST request to mysystem/login and in the request body add {email: string, password: string}. I have tried a few different things and nothing is working. I have to log into the mysystem/login with email and password, then i will be able to connect to mygraphql endpoint from the code below.--i was assuming this portion would go where I have the //smt authentication notes. Any help on how to setup the post request and where it should be or how it should work would be much appreciated.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using SimpleJSON;
using UnityEngine;
using UnityEngine.Networking;
namespace graphQLClient
{
public class GraphQuery : MonoBehaviour
{
public static GraphQuery instance = null;
[Tooltip("The url of the node endpoint of the graphQL server being queried")]
public static string url;
public delegate void QueryComplete();
public static event QueryComplete onQueryComplete;
public enum Status { Neutral, Loading, Complete, Error };
public static Status queryStatus;
public static string queryReturn;
string authURL;
public static string LoginToken;
public class Query
{
public string query;
}
public void Awake()
{
if (instance == null)
{
instance = this;
}
else if (instance != this)
{
Destroy(gameObject);
}
DontDestroyOnLoad(gameObject);
StartCoroutine("PostLogin");
}
private void Start()
{
LoginToken = "";
}
public static Dictionary<string, string> variable = new Dictionary<string, string>();
public static Dictionary<string, string[]> array = new Dictionary<string, string[]>();
// Use this for initialization
// SMT Authentication to ELP
// SMT Needed for Authentication--- if (token != null) request.SetRequestHeader("Authorization", "Bearer " + token);
//In the request body: {email: string, password: string}
//You’ll either get a 401 with an empty response or 201 with {token: string, user: object}
IEnumerator PostLogin()
{
Debug.Log("Logging in...");
string authURL = "https://myapp.com/login";
string loginBody = "{\"email\":\"myemail.com\",\"password\":\"mypassowrd\"}";
var request = new UnityWebRequest(authURL, "POST");
byte[] bodyRaw = new System.Text.UTF8Encoding().GetBytes(loginBody);
request.uploadHandler = (UploadHandler)new UploadHandlerRaw(bodyRaw);
request.downloadHandler = (DownloadHandler)new DownloadHandlerBuffer();
request.SetRequestHeader("Content-Type", "application/json");
yield return request.SendWebRequest();
if (request.isNetworkError || request.isHttpError)
{
Debug.Log("Login error!");
foreach (KeyValuePair<string, string> entry in request.GetResponseHeaders())
{
Debug.Log(entry.Value + "=" + entry.Key);
}
Debug.Log(request.error);
}
else
{
Debug.Log("Login complete!");
//Debug.Log(request.downloadHandler.text);
LoginToken = request.downloadHandler.text;
Debug.Log(LoginToken);
}
}
public static WWW POST(string details)
{
//var request = new UnityWebRequest(url, "POST");
details = QuerySorter(details);
Query query = new Query();
string jsonData = "";
WWWForm form = new WWWForm();
query = new Query { query = details };
jsonData = JsonUtility.ToJson(query);
byte[] postData = Encoding.ASCII.GetBytes(jsonData);
Dictionary<string, string> postHeader = form.headers;
//postHeader["Authorization"] = "Bearer " + downloadHandler.Token;
if (postHeader.ContainsKey("Content-Type"))
//postHeader["Content-Type"] = "application/json";
postHeader.Add("Authorization", "Bearer " + LoginToken);
else
//postHeader.Add("Content-Type", "application/json");
postHeader.Add("Authorization", "Bearer " + LoginToken);
WWW www = new WWW(url, postData, postHeader);
instance.StartCoroutine(WaitForRequest(www));
queryStatus = Status.Loading;
return www;
}
static IEnumerator WaitForRequest(WWW data)
{
yield return data; // Wait until the download is done
if (data.error != null)
{
Debug.Log("There was an error sending request: " + data.error);
queryStatus = Status.Error;
}
else
{
queryReturn = data.text;
queryStatus = Status.Complete;
}
onQueryComplete();
}
public static string QuerySorter(string query)
{
string finalString;
string[] splitString;
string[] separators = { "$", "^" };
splitString = query.Split(separators, StringSplitOptions.RemoveEmptyEntries);
finalString = splitString[0];
for (int i = 1; i < splitString.Length; i++)
{
if (i % 2 == 0)
{
finalString += splitString[i];
}
else
{
if (!splitString[i].Contains("[]"))
{
finalString += variable[splitString[i]];
}
else
{
finalString += ArraySorter(splitString[i]);
}
}
}
return finalString;
}
public static string ArraySorter(string theArray)
{
string[] anArray;
string solution;
anArray = array[theArray];
solution = "[";
foreach (string a in anArray)
{
}
for (int i = 0; i < anArray.Length; i++)
{
solution += anArray[i].Trim(new Char[] { '"' });
if (i < anArray.Length - 1)
solution += ",";
}
solution += "]";
Debug.Log("This is solution " + solution);
return solution;
}
}
}