Report if BackgroundFetcherRateProvider has expired entry

BTCPayServer/BTCPayServer.csproj

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp2.1</TargetFramework>
-		<Version>1.0.2.97</Version>
+		<Version>1.0.2.98</Version>
     <NoWarn>NU1701,CA1816,CA1308,CA1810,CA2208</NoWarn>
   </PropertyGroup>
   <PropertyGroup>

BTCPayServer/Services/Rates/BackgroundFetcherRateProvider.cs

@@ -1,9 +1,11 @@
 using System;
+using Microsoft.Extensions.Logging;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.ExceptionServices;
 using System.Threading.Tasks;
 using BTCPayServer.Data;
+using BTCPayServer.Logging;
 using BTCPayServer.Rating;
 
 namespace BTCPayServer.Services.Rates
@@ -73,7 +75,20 @@ namespace BTCPayServer.Services.Rates
         LatestFetch _Latest;
         public async Task<ExchangeRates> GetRatesAsync()
         {
-            return (_Latest ?? (await Fetch())).GetResult();
+            var latest = _Latest;
+            if(latest != null && latest.Expiration <= DateTimeOffset.UtcNow + TimeSpan.FromSeconds(1.0))
+            {
+                Logs.PayServer.LogWarning($"GetRatesAsync was called on {GetExchangeName()} when the rate is outdated. It should never happen, let BTCPayServer developers know about this.");
+                latest = null;
+            }
+            return (latest ?? (await Fetch())).GetResult();
+        }
+
+        private string GetExchangeName()
+        {
+            if (_Inner is IHasExchangeName exchangeName)
+                return exchangeName.ExchangeName ?? "???";
+            return "???";
         }
 
         private async Task<LatestFetch> Fetch()

BTCPayServer/Services/Rates/BitpayRateProvider.cs

@@ -9,7 +9,7 @@ using BTCPayServer.Rating;
 
 namespace BTCPayServer.Services.Rates
 {
-    public class BitpayRateProvider : IRateProvider
+    public class BitpayRateProvider : IRateProvider, IHasExchangeName
     {
         public const string BitpayName = "bitpay";
         Bitpay _Bitpay;
@@ -20,6 +20,8 @@ namespace BTCPayServer.Services.Rates
             _Bitpay = bitpay;
         }
 
+        public string ExchangeName => BitpayName;
+
         public async Task<ExchangeRates> GetRatesAsync()
         {
             return new ExchangeRates((await _Bitpay.GetRatesAsync().ConfigureAwait(false))

BTCPayServer/Services/Rates/CachedRateProvider.cs

@@ -7,7 +7,7 @@ using Microsoft.Extensions.Caching.Memory;
 
 namespace BTCPayServer.Services.Rates
 {
-    public class CachedRateProvider : IRateProvider
+    public class CachedRateProvider : IRateProvider, IHasExchangeName
     {
         private IRateProvider _Inner;
         private IMemoryCache _MemoryCache;
@@ -31,7 +31,7 @@ namespace BTCPayServer.Services.Rates
             }
         }
 
-        public string ExchangeName { get; set; }
+        public string ExchangeName { get; }
 
         public TimeSpan CacheSpan
         {

BTCPayServer/Services/Rates/CoinAverageRateProvider.cs

@@ -49,7 +49,7 @@ namespace BTCPayServer.Services.Rates
         Task AddHeader(HttpRequestMessage message);
     }
 
-    public class CoinAverageRateProvider : IRateProvider
+    public class CoinAverageRateProvider : IRateProvider, IHasExchangeName
     {
         public const string CoinAverageName = "coinaverage";
         public CoinAverageRateProvider()
@@ -82,6 +82,8 @@ namespace BTCPayServer.Services.Rates
 
         public ICoinAverageAuthenticator Authenticator { get; set; }
 
+        public string ExchangeName => Exchange ?? CoinAverageName;
+
         private bool TryToBidAsk(JProperty p, out BidAsk bidAsk)
         {
             bidAsk = null;

BTCPayServer/Services/Rates/ExchangeSharpRateProvider.cs

@@ -10,7 +10,7 @@ using ExchangeSharp;
 
 namespace BTCPayServer.Services.Rates
 {
-    public class ExchangeSharpRateProvider : IRateProvider
+    public class ExchangeSharpRateProvider : IRateProvider, IHasExchangeName
     {
         readonly ExchangeAPI _ExchangeAPI;
         readonly string _ExchangeName;
@@ -29,6 +29,8 @@ namespace BTCPayServer.Services.Rates
             get; set;
         }
 
+        public string ExchangeName => _ExchangeName;
+
         public async Task<ExchangeRates> GetRatesAsync()
         {
             await new SynchronizationContextRemover();

BTCPayServer/Services/Rates/IHasExchangeName.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Services.Rates
+{
+    public interface IHasExchangeName
+    {
+        string ExchangeName { get; }
+    }
+}

BTCPayServer/Services/Rates/KrakenExchangeRateProvider.cs

@@ -13,7 +13,7 @@ using Newtonsoft.Json.Linq;
 namespace BTCPayServer.Services.Rates
 {
     // Make sure that only one request is sent to kraken in general
-    public class KrakenExchangeRateProvider : IRateProvider
+    public class KrakenExchangeRateProvider : IRateProvider, IHasExchangeName
     {
         public KrakenExchangeRateProvider()
         {
@@ -31,6 +31,9 @@ namespace BTCPayServer.Services.Rates
                 _LocalClient = null;
             }
         }
+
+        public string ExchangeName => "kraken";
+
         HttpClient _LocalClient;
         static HttpClient _Client = new HttpClient();
 

BTCPayServer/Services/Rates/QuadrigacxRateProvider.cs

@@ -9,11 +9,13 @@ using Newtonsoft.Json.Linq;
 
 namespace BTCPayServer.Services.Rates
 {
-    public class QuadrigacxRateProvider : IRateProvider
+    public class QuadrigacxRateProvider : IRateProvider, IHasExchangeName
     {
         public const string QuadrigacxName = "quadrigacx";
         static HttpClient _Client = new HttpClient();
 
+        public string ExchangeName => QuadrigacxName;
+
         private bool TryToBidAsk(JObject p, out BidAsk v)
         {
             v = null;