Schema compare cancel operation (#826)

* First cut of schema compare cancel (private nuget)

* Update Dacfx nuget to a published version

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.cs

@@ -2941,6 +2941,14 @@ namespace Microsoft.SqlTools.ServiceLayer
             }
         }
 
+        public static string SchemaCompareSessionNotFound
+        {
+            get
+            {
+                return Keys.GetString(Keys.SchemaCompareSessionNotFound);
+            }
+        }
+
         public static string ConnectionServiceListDbErrorNotConnected(string uri)
         {
             return Keys.GetString(Keys.ConnectionServiceListDbErrorNotConnected, uri);
@@ -4281,6 +4289,9 @@ namespace Microsoft.SqlTools.ServiceLayer
             public const string OpenScmpConnectionBasedModelParsingError = "OpenScmpConnectionBasedModelParsingError";
 
 
+            public const string SchemaCompareSessionNotFound = "SchemaCompareSessionNotFound";
+
+
             private Keys()
             { }
 

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.resx

@@ -1723,4 +1723,7 @@
     <value>Error encountered while trying to parse connection information for endpoint '{0}' with error message '{1}'</value>
     <comment></comment>
   </data>
+  <data name="SchemaCompareSessionNotFound" xml:space="preserve">
+    <value>Could not find the schema compare session to cancel</value>
+  </data>
 </root>

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.strings

@@ -797,4 +797,5 @@ ExtractInvalidVersion = Invalid version '{0}' passed. Version must be in the for
 # Schema Compare
 PublishChangesTaskName = Apply schema compare changes
 SchemaCompareExcludeIncludeNodeNotFound = Failed to find the specified change in the model
-OpenScmpConnectionBasedModelParsingError = Error encountered while trying to parse connection information for endpoint '{0}' with error message '{1}'
+OpenScmpConnectionBasedModelParsingError = Error encountered while trying to parse connection information for endpoint '{0}' with error message '{1}'
+SchemaCompareSessionNotFound =  Could not find the schema compare session to cancel

src/Microsoft.SqlTools.ServiceLayer/Localization/sr.xlf

@@ -2001,6 +2001,11 @@
         <target state="new">Error encountered while trying to parse connection information for endpoint '{0}' with error message '{1}'</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="SchemaCompareSessionNotFound">
+        <source>Could not find the schema compare session to cancel</source>
+        <target state="new">Could not find the schema compare session to cancel</target>
+        <note></note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/Microsoft.SqlTools.ServiceLayer/Microsoft.SqlTools.ServiceLayer.csproj

@@ -23,7 +23,7 @@
   <ItemGroup>
     <PackageReference Include="System.Data.SqlClient" Version="4.6.0" />
     <PackageReference Include="Microsoft.SqlServer.SqlManagementObjects" Version="$(SmoPackageVersion)" />
-    <PackageReference Include="Microsoft.SqlServer.DacFx" Version="150.4316.1-preview" />
+    <PackageReference Include="Microsoft.SqlServer.DacFx" Version="150.4451.1-preview" />
     <PackageReference Include="System.Text.Encoding.CodePages" Version="4.6.0-preview3-26501-04" />
   </ItemGroup>
   <ItemGroup>

src/Microsoft.SqlTools.ServiceLayer/SchemaCompare/Contracts/SchemaCompareCancellationRequest.cs

@@ -0,0 +1,30 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Utility;
+
+namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare.Contracts
+{
+    /// <summary>
+    /// Parameters for a schema compare cancel request
+    /// </summary>
+    public class SchemaCompareCancelParams
+    {
+        /// <summary>
+        /// Operation id of the schema compare operation
+        /// </summary>
+        public string OperationId { get; set; }
+    }
+
+    /// <summary>
+    /// Defines the Schema Compare cancel comparison request type
+    /// </summary>
+    class SchemaCompareCancellationRequest
+    {
+        public static readonly RequestType<SchemaCompareCancelParams, ResultStatus> Type =
+            RequestType<SchemaCompareCancelParams, ResultStatus>.Create("schemaCompare/cancel");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/SchemaCompare/SchemaCompareGenerateScriptOperation.cs

@@ -57,7 +57,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
 
             try
             {
-                this.ScriptGenerationResult = this.ComparisonResult.GenerateScript(this.Parameters.TargetDatabaseName);
+                this.ScriptGenerationResult = this.ComparisonResult.GenerateScript(this.Parameters.TargetDatabaseName, this.CancellationToken);
 
                 // tests don't create a SqlTask, so only add the script when the SqlTask isn't null
                 if (this.SqlTask != null)
@@ -81,6 +81,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
         // The schema compare public api doesn't currently take a cancellation token so the operation can't be cancelled
         public void Cancel()
         {
+            this.cancellation.Cancel();
         }
 
         /// <summary>

src/Microsoft.SqlTools.ServiceLayer/SchemaCompare/SchemaCompareOperation.cs

@@ -49,7 +49,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
         }
 
         protected CancellationToken CancellationToken { get { return this.cancellation.Token; } }
-
+        
         /// <summary>
         /// The error occurred during operation
         /// </summary>
@@ -58,6 +58,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
         // The schema compare public api doesn't currently take a cancellation token so the operation can't be cancelled
         public void Cancel()
         {
+            this.cancellation.Cancel();
         }
 
         /// <summary>
@@ -91,19 +92,31 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
                     comparison.Options = SchemaCompareUtils.CreateSchemaCompareOptions(this.Parameters.DeploymentOptions);
                 }
 
-                this.ComparisonResult = comparison.Compare();
+                // for testing
+                schemaCompareStarted?.Invoke(this, new EventArgs());
+
+                this.ComparisonResult = comparison.Compare(this.CancellationToken);
 
                 // try one more time if it didn't work the first time
                 if (!this.ComparisonResult.IsValid)
                 {
-                    this.ComparisonResult = comparison.Compare();
+                    this.ComparisonResult = comparison.Compare(this.CancellationToken);
+                }
+
+                // Since DacFx does not throw on schema comparison cancellation, throwing here explicitly to ensure consistency of behavior
+                if (!this.ComparisonResult.IsValid && this.CancellationToken.IsCancellationRequested)
+                {
+                    throw new OperationCanceledException(this.CancellationToken);
                 }
 
                 this.Differences = new List<DiffEntry>();
-                foreach (SchemaDifference difference in this.ComparisonResult.Differences)
+                if (this.ComparisonResult.Differences != null)
                 {
-                    DiffEntry diffEntry = SchemaCompareUtils.CreateDiffEntry(difference, null);
+                    foreach (SchemaDifference difference in this.ComparisonResult.Differences)
-                    this.Differences.Add(diffEntry);
+                    {
+                        DiffEntry diffEntry = SchemaCompareUtils.CreateDiffEntry(difference, null);
+                        this.Differences.Add(diffEntry);
+                    }
                 }
             }
             catch (Exception e)
@@ -113,5 +126,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
                 throw;
             }
         }
+
+        internal event EventHandler<EventArgs> schemaCompareStarted;
     }
 }

src/Microsoft.SqlTools.ServiceLayer/SchemaCompare/SchemaComparePublishChangesOperation.cs

@@ -54,7 +54,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
 
             try
             {
-                this.PublishResult = this.ComparisonResult.PublishChangesToTarget();
+                this.PublishResult = this.ComparisonResult.PublishChangesToTarget(this.CancellationToken);
             }
             catch (Exception e)
             {
@@ -67,6 +67,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
         // The schema compare public api doesn't currently take a cancellation token so the operation can't be cancelled
         public void Cancel()
         {
+            this.cancellation.Cancel();
         }
     }
 }

src/Microsoft.SqlTools.ServiceLayer/SchemaCompare/SchemaCompareService.cs

@@ -14,6 +14,7 @@ using Microsoft.SqlServer.Dac.Compare;
 using Microsoft.SqlTools.ServiceLayer.Utility;
 using Microsoft.SqlTools.Utility;
 using System.Diagnostics;
+using System.Threading;
 
 namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
 {
@@ -27,6 +28,8 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
         private static readonly Lazy<SchemaCompareService> instance = new Lazy<SchemaCompareService>(() => new SchemaCompareService());
         private Lazy<ConcurrentDictionary<string, SchemaComparisonResult>> schemaCompareResults =
             new Lazy<ConcurrentDictionary<string, SchemaComparisonResult>>(() => new ConcurrentDictionary<string, SchemaComparisonResult>());
+        private Lazy<ConcurrentDictionary<string, Action>> currentComparisonCancellationAction =
+            new Lazy<ConcurrentDictionary<string, Action>>(() => new ConcurrentDictionary<string, Action>());
 
         // For testability
         internal Task CurrentSchemaCompareTask;
@@ -46,6 +49,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
         public void InitializeService(ServiceHost serviceHost)
         {
             serviceHost.SetRequestHandler(SchemaCompareRequest.Type, this.HandleSchemaCompareRequest);
+            serviceHost.SetRequestHandler(SchemaCompareCancellationRequest.Type, this.HandleSchemaCompareCancelRequest);
             serviceHost.SetRequestHandler(SchemaCompareGenerateScriptRequest.Type, this.HandleSchemaCompareGenerateScriptRequest);
             serviceHost.SetRequestHandler(SchemaComparePublishChangesRequest.Type, this.HandleSchemaComparePublishChangesRequest);
             serviceHost.SetRequestHandler(SchemaCompareIncludeExcludeNodeRequest.Type, this.HandleSchemaCompareIncludeExcludeNodeRequest);
@@ -78,6 +82,7 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
                     try
                     {
                         operation = new SchemaCompareOperation(parameters, sourceConnInfo, targetConnInfo);
+                        currentComparisonCancellationAction.Value[operation.OperationId] = operation.Cancel;
                         operation.Execute(parameters.TaskExecutionMode);
 
                         // add result to dictionary of results
@@ -110,6 +115,40 @@ namespace Microsoft.SqlTools.ServiceLayer.SchemaCompare
             }
         }
 
+        /// <summary>
+        /// Handles schema compare cancel request
+        /// </summary>
+        /// <returns></returns>
+        public async Task HandleSchemaCompareCancelRequest(SchemaCompareCancelParams parameters, RequestContext<ResultStatus> requestContext)
+        {
+            try
+            {
+                Action cancelAction = null;
+                if (currentComparisonCancellationAction.Value.TryRemove(parameters.OperationId, out cancelAction))
+                {
+                    if(cancelAction != null)
+                    {
+                        cancelAction.Invoke();
+                        await requestContext.SendResult(new ResultStatus()
+                        {
+                            Success = true,
+                            ErrorMessage = null
+                        });
+                    }
+                }
+                await requestContext.SendResult(new ResultStatus()
+                {
+                    Success = false,
+                    ErrorMessage = SR.SchemaCompareSessionNotFound
+                });
+
+            }
+            catch (Exception e)
+            {
+                await requestContext.SendError(e);
+            }
+        }
+
         /// <summary>
         /// Handles request for schema compare generate deploy script
         /// </summary>

test/Microsoft.SqlTools.ManagedBatchParser.IntegrationTests/Microsoft.SqlTools.ManagedBatchParser.IntegrationTests.csproj

@@ -35,7 +35,7 @@
     <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
     <PackageReference Include="System.Data.SqlClient" Version="4.6.0" />
     <PackageReference Include="Microsoft.SqlServer.SqlManagementObjects" Version="$(SmoPackageVersion)" />
-    <PackageReference Include="Microsoft.SqlServer.DacFx" Version="150.4316.1-preview" />
+    <PackageReference Include="Microsoft.SqlServer.DacFx" Version="150.4451.1-preview" />
   </ItemGroup>
   <ItemGroup>
     <Service Include="{82a7f48d-3b50-4b1e-b82e-3ada8210c358}" />

test/Microsoft.SqlTools.ServiceLayer.IntegrationTests/Microsoft.SqlTools.ServiceLayer.IntegrationTests.csproj

@@ -35,7 +35,7 @@
     <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
     <PackageReference Include="System.Data.SqlClient" Version="4.6.0" />
     <PackageReference Include="Microsoft.SqlServer.SqlManagementObjects" Version="$(SmoPackageVersion)" />
-    <PackageReference Include="Microsoft.SqlServer.DacFx" Version="150.4316.1-preview" />
+    <PackageReference Include="Microsoft.SqlServer.DacFx" Version="150.4451.1-preview" />
   </ItemGroup>
   <ItemGroup>
     <Service Include="{82a7f48d-3b50-4b1e-b82e-3ada8210c358}" />

test/Microsoft.SqlTools.ServiceLayer.IntegrationTests/SchemaCompare/SchemaCompareServiceTests.cs

@@ -626,6 +626,56 @@ CREATE TABLE [dbo].[table3]
             }
         }
 
+        /// <summary>
+        /// Verify the schema compare cancel 
+        /// </summary>
+        [Fact]
+        public async void SchemaCompareCancelCompareOperation()
+        {
+            var result = SchemaCompareTestUtils.GetLiveAutoCompleteTestObjects();
+            SqlTestDb sourceDb = await SqlTestDb.CreateNewAsync(TestServerType.OnPrem, false, null, SourceScript, "SchemaCompareSource");
+            SqlTestDb targetDb = await SqlTestDb.CreateNewAsync(TestServerType.OnPrem, false, null, TargetScript, "SchemaCompareTarget");
+
+            try
+            {
+                SchemaCompareEndpointInfo sourceInfo = new SchemaCompareEndpointInfo();
+                SchemaCompareEndpointInfo targetInfo = new SchemaCompareEndpointInfo();
+
+                sourceInfo.EndpointType = SchemaCompareEndpointType.Database;
+                sourceInfo.DatabaseName = sourceDb.DatabaseName;
+                targetInfo.EndpointType = SchemaCompareEndpointType.Database;
+                targetInfo.DatabaseName = targetDb.DatabaseName;
+
+                var schemaCompareParams = new SchemaCompareParams
+                {
+                    SourceEndpointInfo = sourceInfo,
+                    TargetEndpointInfo = targetInfo
+                };
+
+                SchemaCompareOperation schemaCompareOperation = new SchemaCompareOperation(schemaCompareParams, result.ConnectionInfo, result.ConnectionInfo);
+                schemaCompareOperation.schemaCompareStarted += (sender, e) => { schemaCompareOperation.Cancel(); };
+
+                try
+                {
+                    Task cTask = Task.Factory.StartNew(() => schemaCompareOperation.Execute(TaskExecutionMode.Execute));
+                    cTask.Wait();
+                    Assert.False(cTask.IsCompletedSuccessfully, "schema compare task should not complete after cancel");
+                }
+                catch (Exception ex)
+                {
+                    Assert.NotNull(ex.InnerException);
+                    Assert.True(ex.InnerException is OperationCanceledException, $"Exception is expected to be Operation cancelled but actually is {ex.InnerException}");
+                }
+
+                Assert.Null(schemaCompareOperation.ComparisonResult.Differences);
+            }
+            finally
+            {
+                sourceDb.Cleanup();
+                targetDb.Cleanup();
+            }
+        }
+
         private void ValidateSchemaCompareWithExcludeIncludeResults(SchemaCompareOperation schemaCompareOperation)
         {
             schemaCompareOperation.Execute(TaskExecutionMode.Execute);
@@ -732,7 +782,6 @@ CREATE TABLE [dbo].[table3]
             Assert.True(initialScript.Length == afterIncludeScript.Length, $"Changes should be same as inital since we included what we excluded, before {initialScript}, now {afterIncludeScript}");
         }
 
-
         private async Task CreateAndOpenScmp(SchemaCompareEndpointType sourceEndpointType, SchemaCompareEndpointType targetEndpointType)
         {
             SqlTestDb sourceDb = await SqlTestDb.CreateNewAsync(TestServerType.OnPrem, false, null, SourceScript, "SchemaCompareOpenScmpSource");