Feature execution plan settings and request implementation (#213)

* experimental showplan implementation (tools side only)

* fix for redundant massages from showplan executions

* moved showplan batches to new variables to make it less confusing

* returns showplan as part of batch summary with in each result summary

* cleaned up showplan resultsets

* cleaning up code and making showplan var optional

* changes all var names to showplan

* adding estimated support

* small fixes

* updatin var names and adding EPOptions struct

* adding ssms execution plan logic based on server types

* adding special actions logic

* removing redundant name changes

* execution plan query handler added

* cleaning up functions and data structures

* seperated special actions into its own class

* cleaning up special actions

* cleaning up code

* small new line fixes

* commenting out pre-yukon code

* removing all pre yukon code

* last yukon code commented out

* fixes broken tests

* adding related unit tests; integration tests incoming

* finishing tests and cleaning up code

* semantic changes

* cleaning up semantics

* changes and test fixes, also adding new exceptions into RS

* fixing special actions and cleaning up request logic

* fixing comment to trigger new build

* triggering another  build

* fixed up specialaction and added tests for it

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/QueryExecutionService.cs

@@ -126,6 +126,7 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
             serviceHost.SetRequestHandler(QueryCancelRequest.Type, HandleCancelRequest);
             serviceHost.SetRequestHandler(SaveResultsAsCsvRequest.Type, HandleSaveResultsAsCsvRequest);
             serviceHost.SetRequestHandler(SaveResultsAsJsonRequest.Type, HandleSaveResultsAsJsonRequest);
+            serviceHost.SetRequestHandler(QueryExecutionPlanRequest.Type, HandleExecutionPlanRequest);
 
             // Register handler for shutdown event
             serviceHost.RegisterShutdownTask((shutdownParams, requestContext) =>
@@ -208,6 +209,36 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
             }
         }
 
+         /// <summary>
+        /// Handles a request to get an execution plan
+        /// </summary>
+        public async Task HandleExecutionPlanRequest(QueryExecutionPlanParams planParams,
+            RequestContext<QueryExecutionPlanResult> requestContext)
+        {
+            try
+            {
+                // Attempt to load the query
+                Query query;
+                if (!ActiveQueries.TryGetValue(planParams.OwnerUri, out query))
+                {
+                    await requestContext.SendError(SR.QueryServiceRequestsNoQuery);
+                    return;
+                }
+
+                // Retrieve the requested execution plan and return it
+                var result = new QueryExecutionPlanResult
+                {
+                    ExecutionPlan = await query.GetExecutionPlan(planParams.BatchIndex, planParams.ResultSetIndex)
+                };
+                await requestContext.SendResult(result);
+            }
+            catch (Exception e)
+            {
+                // This was unexpected, so send back as error
+                await requestContext.SendError(e.Message);
+            }
+        }
+
         /// <summary>
         /// Handles a request to dispose of this query
         /// </summary>
@@ -334,6 +365,9 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
                 // Retrieve the current settings for executing the query with
                 QueryExecutionSettings settings = WorkspaceService.CurrentSettings.QueryExecutionSettings;
 
+                // Apply execution parameter settings 
+                settings.ExecutionPlanOptions = executeParams.ExecutionPlanOptions;
+
                 // Get query text from the workspace.
                 ScriptFile queryFile = WorkspaceService.Workspace.GetFile(executeParams.OwnerUri);
 
@@ -425,6 +459,7 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
                     BatchSummary = b.Summary,
                     OwnerUri = executeParams.OwnerUri
                 };
+
                 await requestContext.SendEvent(QueryExecuteBatchStartEvent.Type, eventParams);
             };
             query.BatchStarted += batchStartCallback;
@@ -436,6 +471,7 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
                     BatchSummary = b.Summary,
                     OwnerUri = executeParams.OwnerUri
                 };
+
                 await requestContext.SendEvent(QueryExecuteBatchCompleteEvent.Type, eventParams);
             };
             query.BatchCompleted += batchCompleteCallback;