Merge pull request #244 from reisenberger/reisenberger/feature/expandcontextusage

v5.1.0: Allow different parts of an execution to exchange state through `Context` flowing with execution

Author: joelhulen

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 5.1.0
+- Allow different parts of a policy execution to exchange data via a mutable Context travelling with each execution.
+
 ## 5.0.6
 - Update NETStandard.Library dependency to latest 1.6.1 for .NetStandard1.0 target.  Resolves compatibility for some Xamarin targets.
 
@@ -33,12 +36,14 @@
 ## 5.0.0 alpha
 
 A major release, adding significant new resilience policies:
+
 - Timeout policy: allows timing out any execution. Thanks to [@reisenberger](https://github.com/reisenberger).
 - Bulkhead isolation policy: limits the resources consumable by governed actions, such that a faulting channel cannot cause cascading failures. Thanks to [@reisenberger](https://github.com/reisenberger) and contributions from [@brunolauze](https://github.com/brunolauze).
 - Fallback policy: provides for a fallback execution or value, in case of overall failure. Thanks to [@reisenberger](https://github.com/reisenberger)
 - PolicyWrap: allows flexibly combining Policy instances of any type, to form an overall resilience strategy. Thanks to [@reisenberger](https://github.com/reisenberger)
 
 Other changes include:
+
 - Add PolicyKeys and context to all policy executions, for logging and to support later introduction of policy events and metrics. Thanks to [@reisenberger](https://github.com/reisenberger)
 - Add CancellationToken support to synchronous executions.  Thanks to [@brunolauze](https://github.com/brunolauze) and [@reisenberger](https://github.com/reisenberger)
 - Add some missing ExecuteAndCapture/Async overloads. Thanks to [@reisenberger](https://github.com/reisenberger)

GitVersionConfig.yaml

@@ -1 +1 @@
-next-version: 5.0.6
+next-version: 5.1.0

README.md

@@ -79,12 +79,12 @@ From Polly v4.3.0 onwards, policies wrapping calls returning a `TResult` can als
 ```csharp
 // Handle return value with condition 
 Policy
-  .HandleResult<HttpResponse>(r => r.StatusCode == 404)
+  .HandleResult<HttpResponseMessage>(r => r.StatusCode == 404)
 
 // Handle multiple return values 
 Policy
-  .HandleResult<HttpResponse>(r => r.StatusCode == 500)
-  .OrResult<HttpResponse>(r => r.StatusCode == 502)
+  .HandleResult<HttpResponseMessage>(r => r.StatusCode == 500)
+  .OrResult<HttpResponseMessage>(r => r.StatusCode == 502)
 
 // Handle primitive return values (implied use of .Equals())
 Policy
@@ -93,9 +93,9 @@ Policy
 
 // Handle both exceptions and return values in one policy
 int[] httpStatusCodesWorthRetrying = {408, 500, 502, 503, 504}; 
-HttpResponse result = Policy
-  .Handle<HttpException>()
-  .OrResult<HttpResponse>(r => httpStatusCodesWorthRetrying.Contains(r.StatusCode))
+HttpResponseMessage result = Policy
+  .Handle<HttpResponseException>()
+  .OrResult<HttpResponseMessage>(r => httpStatusCodesWorthRetrying.Contains(r.StatusCode))
 ```
 
 For more information, see [Handling Return Values](#handing-return-values-and-policytresult) at foot of this readme. 
@@ -723,11 +723,11 @@ As described at step 1b, from Polly v4.3.0 onwards, policies can handle return v
 ```csharp
 // Handle both exceptions and return values in one policy
 int[] httpStatusCodesWorthRetrying = {408, 500, 502, 503, 504}; 
-HttpResponse result = Policy
-  .Handle<HttpException>()
-  .OrResult<HttpResponse>(r => httpStatusCodesWorthRetrying.Contains(r.StatusCode))
+HttpResponseMessage result = Policy
+  .Handle<HttpResponseException>()
+  .OrResult<HttpResponseMessage>(r => httpStatusCodesWorthRetrying.Contains(r.StatusCode))
   .Retry(...)
-  .Execute( /* some Func<HttpResponse> */ )
+  .Execute( /* some Func<HttpResponseMessage> */ )
 ```
 
 The exceptions and return results to handle can be expressed fluently in any order.
@@ -825,6 +825,7 @@ For details of changes by release see the [change log](https://github.com/App-vN
 * [@lakario](https://github.com/lakario) - Tidy CircuitBreaker LastException property.
 * [@lakario](https://github.com/lakario) - Add NoOpPolicy.
 * [@Julien-Mialon](https://github.com/Julien-Mialon) - Fixes, support and examples for .NETStandard compatibility with Xamarin PCL projects
+* [@reisenberger](https://github.com/reisenberger) - Add mutable Context and extra overloads taking Context.  Allows different parts of a policy execution to exchange data via the mutable Context travelling with each execution.
 
 # Sample Projects
 

src/Polly.Net40Async.nuspec

@@ -15,6 +15,10 @@
     <releaseNotes>
      v5.0 is a major release with significant new resilience policies: Timeout; Bulkhead Isolation; Fallback; and PolicyWrap.  See release notes back to v5.0.0 for full details.
 
+     5.1.0
+     ---------------------
+     - Allow different parts of a policy execution to exchange data via a mutable Context travelling with each execution.
+
      5.0.6
      ---------------------
      - (.NETStandard1.0 changes only.)

src/Polly.NetStandard10/Properties/AssemblyInfo.cs

@@ -3,7 +3,7 @@
 using System.Runtime.CompilerServices;
 
 [assembly: AssemblyTitle("Polly")]
-[assembly: AssemblyVersion("5.0.6.0")]
+[assembly: AssemblyVersion("5.1.0.0")]
 [assembly: CLSCompliant(true)]
 
 [assembly: InternalsVisibleTo("Polly.Pcl.Specs")]

src/Polly.Shared/Bulkhead/BulkheadEngine.cs

@@ -13,7 +13,7 @@ namespace Polly.Bulkhead
     internal static partial class BulkheadEngine
     {
         internal static TResult Implementation<TResult>(
-            Func<CancellationToken, TResult> action,
+            Func<Context, CancellationToken, TResult> action,
             Context context,
             Action<Context> onBulkheadRejected,
             SemaphoreSlim maxParallelizationSemaphore,
@@ -31,7 +31,7 @@ internal static TResult Implementation<TResult>(
                 maxParallelizationSemaphore.Wait(cancellationToken);
                 try
                 {
-                    return action(cancellationToken);
+                    return action(context, cancellationToken);
                 }
                 finally
                 {

src/Polly.Shared/Bulkhead/BulkheadEngineAsync.cs

@@ -14,7 +14,7 @@ namespace Polly.Bulkhead
    internal static partial class BulkheadEngine
     {
        internal static async Task<TResult> ImplementationAsync<TResult>(
-            Func<CancellationToken, Task<TResult>> action,
+            Func<Context, CancellationToken, Task<TResult>> action,
             Context context,
             Func<Context, Task> onBulkheadRejectedAsync,
             SemaphoreSlim maxParallelizationSemaphore,
@@ -33,7 +33,7 @@ internal static async Task<TResult> ImplementationAsync<TResult>(
 
                 try 
                 {
-                    return await action(cancellationToken).ConfigureAwait(continueOnCapturedContext);
+                    return await action(context, cancellationToken).ConfigureAwait(continueOnCapturedContext);
                 }
                 finally
                 {

src/Polly.Shared/Bulkhead/BulkheadPolicy.cs

@@ -21,7 +21,7 @@ public partial class BulkheadPolicy : Policy, IDisposable
         private readonly int _maxQueueingActions;
 
         internal BulkheadPolicy(
-            Action<Action<CancellationToken>, Context, CancellationToken> exceptionPolicy, 
+            Action<Action<Context, CancellationToken>, Context, CancellationToken> exceptionPolicy, 
             int maxParallelization,
             int maxQueueingActions,
             SemaphoreSlim maxParallelizationSemaphore, 
@@ -66,7 +66,7 @@ public partial class BulkheadPolicy<TResult> : Policy<TResult>, IDisposable
         private readonly int _maxQueueingActions;
 
         internal BulkheadPolicy(
-            Func<Func<CancellationToken, TResult>, Context, CancellationToken, TResult> executionPolicy,
+            Func<Func<Context, CancellationToken, TResult>, Context, CancellationToken, TResult> executionPolicy,
             int maxParallelization,
             int maxQueueingActions,
             SemaphoreSlim maxParallelizationSemaphore,

src/Polly.Shared/Bulkhead/BulkheadPolicyAsync.cs

@@ -13,7 +13,7 @@ namespace Polly.Bulkhead
 {
     public partial class BulkheadPolicy
     {
-        internal BulkheadPolicy(Func<Func<CancellationToken, Task>, Context, CancellationToken, bool, Task> asyncExceptionPolicy,
+        internal BulkheadPolicy(Func<Func<Context, CancellationToken, Task>, Context, CancellationToken, bool, Task> asyncExceptionPolicy,
             int maxParallelization,
             int maxQueueingActions,
             SemaphoreSlim maxParallelizationSemaphore,
@@ -30,7 +30,7 @@ internal BulkheadPolicy(Func<Func<CancellationToken, Task>, Context, Cancellatio
     public partial class BulkheadPolicy<TResult>
     {
         internal BulkheadPolicy(
-            Func<Func<CancellationToken, Task<TResult>>, Context, CancellationToken, bool, Task<TResult>> asyncExecutionPolicy,
+            Func<Func<Context, CancellationToken, Task<TResult>>, Context, CancellationToken, bool, Task<TResult>> asyncExecutionPolicy,
             int maxParallelization,
             int maxQueueingActions,
             SemaphoreSlim maxParallelizationSemaphore,

src/Polly.Shared/Bulkhead/BulkheadSyntax.cs

@@ -81,7 +81,7 @@ public static BulkheadPolicy Bulkhead(int maxParallelization, int maxQueuingActi
 
             return new BulkheadPolicy(
                 (action, context, cancellationToken) => BulkheadEngine.Implementation(
-                    ct => { action(ct); return EmptyStruct.Instance; },
+                    (ctx, ct) => { action(ctx, ct); return EmptyStruct.Instance; },
                     context,
                     onBulkheadRejected,
                     maxParallelizationSemaphore,