fix: replace infinite retries with exponential backoff strategy in file representations

Box.V2.Test/Box.V2.Test.csproj

@@ -47,6 +47,12 @@
     <None Update="Fixtures\BoxFileRequest\GetFileRequest200.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <None Update="Fixtures\BoxFiles\PollRepresentationPending200.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+    <None Update="Fixtures\BoxFiles\GetRepresentationContentPending200.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="Fixtures\BoxFiles\CreateFileSharedLink200.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>

Box.V2.Test/BoxFilesManagerTest.cs

@@ -4,7 +4,6 @@
 using System.IO;
 using System.Linq;
 using System.Net.Http;
-using System.Net.Http.Headers;
 using System.Text;
 using System.Threading.Tasks;
 using Box.V2.Exceptions;
@@ -1201,5 +1200,110 @@ public async Task DownloadZip_ValidResponse()
                 Assert.AreNotEqual(fs.Length, 0);
             }
         }
+
+
+        [TestMethod]
+        [ExpectedException(typeof(BoxCodingException))]
+        public async Task GetRepresentationContentAsync_ShouldThrowException_IfTooManyRetriesAndHandleRetryTrue()
+        {
+            Handler.SetupSequence(h => h.ExecuteAsync<BoxFile>(It.IsAny<IBoxRequest>()))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     StatusCode = System.Net.HttpStatusCode.Accepted,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     StatusCode = System.Net.HttpStatusCode.Accepted,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     StatusCode = System.Net.HttpStatusCode.Accepted,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     StatusCode = System.Net.HttpStatusCode.Accepted,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     StatusCode = System.Net.HttpStatusCode.Accepted,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     StatusCode = System.Net.HttpStatusCode.Accepted,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }));
+
+            var repRequest = new BoxRepresentationRequest
+            {
+                FileId = "11111",
+                XRepHints = $"[jpg?dimensions=320x320]",
+                HandleRetry = true
+            };
+
+            var result = await _filesManager.GetRepresentationContentAsync(repRequest);
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(BoxCodingException))]
+        public async Task GetRepresentationContentAsync_ShouldThrowException_IfTooManyRetries()
+        {
+            Handler.Setup(h => h.ExecuteAsync<BoxFile>(It.IsAny<IBoxRequest>()))
+                 .Returns(Task.FromResult<IBoxResponse<BoxFile>>(new BoxResponse<BoxFile>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/GetRepresentationContentPending200.json")
+                 }));
+
+            Handler.SetupSequence(h => h.ExecuteAsync<BoxRepresentation>(It.IsAny<IBoxRequest>()))
+                 .Returns(Task.FromResult<IBoxResponse<BoxRepresentation>>(new BoxResponse<BoxRepresentation>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/PollRepresentationPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxRepresentation>>(new BoxResponse<BoxRepresentation>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/PollRepresentationPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxRepresentation>>(new BoxResponse<BoxRepresentation>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/PollRepresentationPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxRepresentation>>(new BoxResponse<BoxRepresentation>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/PollRepresentationPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxRepresentation>>(new BoxResponse<BoxRepresentation>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/PollRepresentationPending200.json")
+                 }))
+                 .Returns(Task.FromResult<IBoxResponse<BoxRepresentation>>(new BoxResponse<BoxRepresentation>()
+                 {
+                     Status = ResponseStatus.Success,
+                     ContentString = LoadFixtureFromJson("Fixtures/BoxFiles/PollRepresentationPending200.json")
+                 }));
+
+            var repRequest = new BoxRepresentationRequest
+            {
+                FileId = "11111",
+                XRepHints = $"[jpg?dimensions=320x320]",
+            };
+
+            var result = await _filesManager.GetRepresentationContentAsync(repRequest);
+        }
     }
 }

Box.V2.Test/BoxResourceManagerTest.cs

@@ -6,6 +6,7 @@
 using Box.V2.Converter;
 using Box.V2.Request;
 using Box.V2.Services;
+using Box.V2.Test.Helpers;
 using Moq;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
@@ -49,6 +50,7 @@ protected BoxResourceManagerTest()
             Config.SetupGet(x => x.SignRequestsEndpointUri).Returns(SignRequestUri);
             Config.SetupGet(x => x.SignRequestsEndpointWithPathUri).Returns(SignRequestWithPathUri);
             Config.SetupGet(x => x.FileRequestsEndpointWithPathUri).Returns(FileRequestsWithPathUri);
+            Config.SetupGet(x => x.RetryStrategy).Returns(new InstantRetryStrategy());
 
             AuthRepository = new AuthRepository(Config.Object, Service, Converter, new OAuthSession("fakeAccessToken", "fakeRefreshToken", 3600, "bearer"));
         }

Box.V2.Test/Fixtures/BoxFiles/GetRepresentationContentPending200.json

@@ -0,0 +1,27 @@
+{
+  "type": "file",
+  "id": "11111",
+  "etag": "0",
+  "representations": {
+    "entries": [
+      {
+        "representation": "jpg",
+        "properties": {
+          "dimensions": "320x320",
+          "paged": "false",
+          "thumb": "false"
+        },
+        "info": {
+          "url": "https://api.box.com/2.0/internal_files/11111/versions/22222/representations/jpg_320x320"
+        },
+        "status": {
+          "state": "pending"
+        },
+        "content": {
+          "url_template": "https://dl.boxcloud.com/api/2.0/internal_files/11111/versions/22222/representations/jpg_320x320/content/{+asset_path}"
+        }
+      }
+    ]
+  }
+}
+

Box.V2.Test/Fixtures/BoxFiles/PollRepresentationPending200.json

@@ -0,0 +1,17 @@
+{
+  "representation": "jpg",
+  "properties": {
+    "dimensions": "320x320",
+    "paged": "false",
+    "thumb": "false"
+  },
+  "info": {
+    "url": "https://api.box.com/2.0/internal_files/11111/versions/22222/representations/jpg_320x320"
+  },
+  "status": {
+    "state": "pending"
+  },
+  "content": {
+    "url_template": "https://dl.boxcloud.com/api/2.0/internal_files/11111/versions/22222/representations/jpg_320x320/content/{+asset_path}"
+  }
+}

Box.V2/Config/BoxConfig.cs

@@ -66,6 +66,7 @@ public BoxConfig(BoxConfigBuilder builder)
             AcceptEncoding = builder.AcceptEncoding;
             WebProxy = builder.WebProxy;
             Timeout = builder.Timeout;
+            RetryStrategy = builder.RetryStrategy;
         }
 
         /// <summary>
@@ -292,6 +293,11 @@ public Uri BoxAuthTokenApiUri
         /// Timeout for the connection
         /// </summary>
         public TimeSpan? Timeout { get; private set; }
+
+        /// <summary>
+        /// Retry strategy for failed requests
+        /// </summary>
+        public IRetryStrategy RetryStrategy { get; private set; } = new ExponentialBackoff();
     }
 
     public enum CompressionType

Box.V2/Config/BoxConfigBuilder.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Net;
+using Box.V2.Utility;
 
 namespace Box.V2.Config
 {
@@ -251,6 +252,17 @@ public BoxConfigBuilder SetEnterpriseId(string enterpriseId)
             return this;
         }
 
+        /// <summary>
+        /// Sets retry strategy.
+        /// </summary>
+        /// <param name="enterpriseId">Retry strategy.</param>
+        /// <returns>this BoxConfigBuilder object for chaining</returns>
+        public BoxConfigBuilder SetRetryStrategy(IRetryStrategy retryStrategy)
+        {
+            RetryStrategy = retryStrategy;
+            return this;
+        }
+
         public string ClientId { get; private set; }
         public string ClientSecret { get; private set; }
         public string EnterpriseId { get; private set; }
@@ -298,6 +310,11 @@ public Uri BoxAuthTokenApiUri
         /// </summary>
         public TimeSpan? Timeout { get; private set; }
 
+        /// <summary>
+        /// Retry strategy for failed requests
+        /// </summary>
+        public IRetryStrategy RetryStrategy { get; private set; } = new ExponentialBackoff();
+
         private Uri EnsureEndsWithSlash(Uri uri)
         {
             return uri.ToString().EndsWith("/") ? uri : new Uri($"{uri}{"/"}");

Box.V2/Config/IBoxConfig.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Net;
+using Box.V2.Utility;
 
 namespace Box.V2.Config
 {
@@ -143,5 +144,9 @@ public interface IBoxConfig
         /// Timeout for the connection
         /// </summary>
         TimeSpan? Timeout { get; }
+        /// <summary>
+        /// Retry strategy for failed requests
+        /// </summary>
+        IRetryStrategy RetryStrategy { get; }
     }
 }

Box.V2/Managers/BoxFilesManager.cs

@@ -15,6 +15,7 @@
 using Box.V2.Extensions;
 using Box.V2.Models;
 using Box.V2.Models.Request;
+using Box.V2.Request;
 using Box.V2.Services;
 using Box.V2.Utility;
 using Newtonsoft.Json.Linq;
@@ -1300,11 +1301,14 @@ public async Task<BoxRepresentationCollection<BoxRepresentation>> GetRepresentat
 
             IBoxResponse<BoxFile> response = await ToResponseAsync<BoxFile>(request).ConfigureAwait(false);
 
+            var retryCounter = 1;
+
             while (response.StatusCode == HttpStatusCode.Accepted && representationRequest.HandleRetry)
             {
-                const int RepresentationRequestRetryTime = 3000;
-                await Task.Delay(RepresentationRequestRetryTime);
-                response = await ToResponseAsync<BoxFile>(request).ConfigureAwait(false);
+                response = await CallWithRetryCheck(() => ToResponseAsync<BoxFile>(request),
+                    $"Could not get valid File Representation status after {retryCounter} retries.",
+                    retryCounter++)
+                    .ConfigureAwait(false);
             }
 
             return response.ResponseObject.Representations;
@@ -1396,7 +1400,7 @@ private async Task<BoxZip> CreateZip(BoxZipRequest zipRequest)
             return response.ResponseObject;
         }
 
-        private async Task<string> PollRepresentationInfo(string infoUrl)
+        private async Task<string> PollRepresentationInfo(string infoUrl, int retryCounter = 1)
         {
             var infoRequest = new BoxRequest(new Uri(infoUrl));
             IBoxResponse<BoxRepresentation> infoResponse = await ToResponseAsync<BoxRepresentation>(infoRequest).ConfigureAwait(false);
@@ -1410,12 +1414,27 @@ private async Task<string> PollRepresentationInfo(string infoUrl)
                     throw new BoxCodingException("Representation had error status");
                 case "none":
                 case "pending":
-                    await Task.Delay(1000);
-                    return await PollRepresentationInfo(infoUrl).ConfigureAwait(false);
+                    return await CallWithRetryCheck(() => PollRepresentationInfo(infoUrl, ++retryCounter),
+                        $"Could not get valid Representation status after {retryCounter} retries.",
+                        retryCounter)
+                        .ConfigureAwait(false);
                 default:
                     throw new BoxCodingException("Representation has unknown status");
             }
         }
+
+        private async Task<T> CallWithRetryCheck<T>(Func<Task<T>> action, string errorMessage, int retryCounter = 1) where T : class
+        {
+            if (retryCounter <= HttpRequestHandler.RetryLimit)
+            {
+                await Task.Delay(_config.RetryStrategy.GetRetryTimeout(retryCounter));
+                return await action().ConfigureAwait(false);
+            }
+            else
+            {
+                throw new BoxCodingException(errorMessage);
+            }
+        }
     }
 
     internal static class UploadUsingSessionInternal