Add support for ProcessingSource instances to refresh their exposed tables (#399)

* Add support for ProcessingSource instances to refresh their exposed tables

* Add docstring

Author: mslukebo

src/Microsoft.Performance.SDK.Tests/ProcessingSourceTests.cs

@@ -229,6 +229,56 @@ public void WhenDiscoveryProvidesDuplicateTables_DiscoveryThrows()
             Assert.ThrowsException<InvalidOperationException>(() => sut.SetApplicationEnvironment(applicationEnvironment));
         }
 
+        [TestMethod]
+        [UnitTest]
+        public void RefreshTablesUpdatesTables()
+        {
+            var tableProvider = new StubTableProvider();
+
+            List<TableDescriptor> SetDiscoveredTables(params Type[] tables)
+            {
+                var tableDescriptors = TableDescriptorUtils.CreateTableDescriptors(serializer, tables);
+                tableProvider.DiscoverReturnValue = tableDescriptors;
+                return tableDescriptors;
+            }
+
+            var initialTableDescriptors = SetDiscoveredTables(
+                typeof(StubDataTableOne),
+                typeof(StubDataTableTwo),
+                typeof(StubMetadataTableOne),
+                typeof(StubMetadataTableTwo));
+
+            var sut = new CreateTableProviderBasedStubDataSource(tableProvider);
+            sut.SetApplicationEnvironment(this.applicationEnvironment);
+
+            AssertCorrectTableDescriptorsAreExposed(initialTableDescriptors, sut);
+
+            var refreshedTableDescriptors = SetDiscoveredTables(
+                typeof(StubDataTableOne),
+                typeof(StubMetadataTableOne));
+
+            sut.CallRefreshTables();
+
+            AssertCorrectTableDescriptorsAreExposed(refreshedTableDescriptors, sut);
+        }
+
+        private void AssertCorrectTableDescriptorsAreExposed(
+            IReadOnlyCollection<TableDescriptor> expected,
+            ProcessingSource processingSource)
+        {
+            CollectionAssert.AreEquivalent(
+                expected
+                    .Where(t => !t.IsMetadataTable)
+                    .ToList(),
+                processingSource.DataTables.ToList());
+
+            CollectionAssert.AreEquivalent(
+                expected
+                    .Where(t => t.IsMetadataTable)
+                    .ToList(),
+                processingSource.MetadataTables.ToList());
+        }
+
         private abstract class StubDataSource
             : ProcessingSource
         {
@@ -283,6 +333,11 @@ protected override bool IsDataSourceSupportedCore(IDataSource dataSource)
             {
                 return true;
             }
+
+            public void CallRefreshTables()
+            {
+                RefreshTables();
+            }
         }
 
         [ProcessingSource("{CABDB99F-F182-457B-B0B4-AD3DD62272D8}", "One", "One")]

src/Microsoft.Performance.SDK/Processing/ProcessingSource.cs

@@ -24,7 +24,7 @@ public abstract class ProcessingSource
         private readonly HashSet<TableDescriptor> metadataTables;
         private readonly ReadOnlyHashSet<TableDescriptor> metadataTablesRO;
 
-        // todo: when the constructor that takes a table provider is removed in v2, this should 
+        // todo: when the constructor that takes a table provider is removed in v2, this should
         // be removed.
         private readonly IProcessingSourceTableProvider tableProvider;
 
@@ -51,7 +51,7 @@ protected ProcessingSource()
         ///     requests the Engine to enable or build a <see cref="TableDescriptor"/> that is in this list, the
         ///     <see cref="TableDescriptor"/> will be passed into
         ///     <see cref="ICustomDataProcessor.EnableTable(TableDescriptor)"/> or
-        ///     <see cref="ICustomDataProcessor.BuildTable(TableDescriptor, ITableBuilder)"/> for the 
+        ///     <see cref="ICustomDataProcessor.BuildTable(TableDescriptor, ITableBuilder)"/> for the
         ///     <see cref="ICustomDataProcessor"/> returned from
         ///     <see cref="ProcessingSource.CreateProcessor(IDataSource, IProcessorEnvironment, ProcessorOptions)"/>
         ///     or
@@ -273,7 +273,7 @@ protected abstract ICustomDataProcessor CreateProcessorCore(
             IEnumerable<IDataSource> dataSources,
             IProcessorEnvironment processorEnvironment,
             ProcessorOptions options);
-        
+
         /// <summary>
         ///     When implemented in a derived class, creates a new
         ///     instance implementing <see cref="ICustomDataProcessor"/>
@@ -308,9 +308,9 @@ protected virtual ICustomDataProcessor CreateProcessorCore(
                 throw new InvalidOperationException(
                     $"Prior to V2, you must override the {nameof(CreateProcessorCore)} which accepts a {nameof(IDataSourceGroup)} when implementing {nameof(IDataSourceGrouper)}");
             }
-            
+
             this.Logger.Warn($"{this.GetType().Name} does not support processing user-specified processing groups - falling back to default processing.");
-	
+
             // Call v1 methods for now
             if (!(dataSourceGroup.ProcessingMode is DefaultProcessingMode))
             {
@@ -354,6 +354,25 @@ protected virtual void SetLoggerCore(ILogger logger)
         {
         }
 
+        /// <summary>
+        ///     Refreshes the tables expoed by this <see cref="ProcessingSource"/>. This method
+        ///     will re-run the <see cref="IProcessingSourceTableProvider"/> associated with
+        ///     this <see cref="ProcessingSource"/> and update <see cref="DataTables"/> and
+        ///     <see cref="MetadataTables"/> accordingly.
+        /// </summary>
+        /// <exception cref="InvalidOperationException">
+        ///     The application environment has not yet been set.
+        /// </exception>
+        protected void RefreshTables()
+        {
+            if (this.ApplicationEnvironment == null)
+            {
+                throw new InvalidOperationException("The application environment has not been set.");
+            }
+
+            this.InitializeAllTables(this.ApplicationEnvironment.Serializer);
+        }
+
         /// <summary>
         ///     A derived class may implement this to provide a custom <see cref="IProcessingSourceTableProvider"/>.
         /// </summary>
@@ -369,6 +388,9 @@ private void InitializeAllTables(ITableConfigurationsSerializer tableConfigSeria
         {
             Debug.Assert(tableConfigSerializer != null);
 
+            this.allTables.Clear();
+            this.metadataTables.Clear();
+
             IProcessingSourceTableProvider tableProvider = CreateTableProvider();
             if (tableProvider == null)
             {