Improve debugger's variable population mechanism

src/PowerShellEditorServices/Services/DebugAdapter/DebugService.cs

@@ -46,6 +46,7 @@ internal class DebugService
         private List<VariableDetailsBase> variables;
         private VariableContainerDetails globalScopeVariables;
         private VariableContainerDetails scriptScopeVariables;
+        private VariableContainerDetails localScopeVariables;
         private StackFrameDetails[] stackFrameDetails;
         private readonly PropertyInfo invocationTypeScriptPositionProperty;
 
@@ -446,11 +447,6 @@ public async Task<string> SetVariableAsync(int variableContainerReferenceId, str
                 for (int i = 0; i < stackFrames.Length; i++)
                 {
                     var stackFrame = stackFrames[i];
-                    if (stackFrame.LocalVariables.ContainsVariable(variable.Id))
-                    {
-                        scope = i.ToString();
-                        break;
-                    }
                 }
             }
 
@@ -627,13 +623,12 @@ internal async Task<StackFrameDetails[]> GetStackFramesAsync(CancellationToken c
         public VariableScope[] GetVariableScopes(int stackFrameId)
         {
             var stackFrames = this.GetStackFrames();
-            int localStackFrameVariableId = stackFrames[stackFrameId].LocalVariables.Id;
             int autoVariablesId = stackFrames[stackFrameId].AutoVariables.Id;
 
             return new VariableScope[]
             {
                 new VariableScope(autoVariablesId, VariableContainerDetails.AutoVariablesName),
-                new VariableScope(localStackFrameVariableId, VariableContainerDetails.LocalScopeName),
+                new VariableScope(this.localScopeVariables.Id, VariableContainerDetails.LocalScopeName),
                 new VariableScope(this.scriptScopeVariables.Id, VariableContainerDetails.ScriptScopeName),
                 new VariableScope(this.globalScopeVariables.Id, VariableContainerDetails.GlobalScopeName),
             };
@@ -656,27 +651,26 @@ private async Task FetchStackFramesAndVariablesAsync(string scriptNameOverride)
                     new VariableDetails("Dummy", null)
                 };
 
-                // Must retrieve global/script variales before stack frame variables
-                // as we check stack frame variables against globals.
-                await FetchGlobalAndScriptVariablesAsync().ConfigureAwait(false);
+
+                // Must retrieve in order of broadest to narrowest scope for efficient deduplication: global, script, local
+                this.globalScopeVariables =
+                    await FetchVariableContainerAsync(VariableContainerDetails.GlobalScopeName, null).ConfigureAwait(false);
+
+                this.scriptScopeVariables =
+                    await FetchVariableContainerAsync(VariableContainerDetails.ScriptScopeName, null).ConfigureAwait(false);
+
+                this.localScopeVariables =
+                    await FetchVariableContainerAsync(VariableContainerDetails.ScriptScopeName, null).ConfigureAwait(false);
+
                 await FetchStackFramesAsync(scriptNameOverride).ConfigureAwait(false);
+
             }
             finally
             {
                 this.debugInfoHandle.Release();
             }
         }
 
-        private async Task FetchGlobalAndScriptVariablesAsync()
-        {
-            // Retrieve globals first as script variable retrieval needs to search globals.
-            this.globalScopeVariables =
-                await FetchVariableContainerAsync(VariableContainerDetails.GlobalScopeName, null).ConfigureAwait(false);
-
-            this.scriptScopeVariables =
-                await FetchVariableContainerAsync(VariableContainerDetails.ScriptScopeName, null).ConfigureAwait(false);
-        }
-
         private async Task<VariableContainerDetails> FetchVariableContainerAsync(
             string scope,
             VariableContainerDetails autoVariables)
@@ -849,9 +843,6 @@ private async Task FetchStackFramesAsync(string scriptNameOverride)
 
                 variables.Add(autoVariables);
 
-                var localVariables = new VariableContainerDetails(nextVariableId++, callStackFrame.ToString());
-                variables.Add(localVariables);
-
                 foreach (DictionaryEntry entry in callStackVariables)
                 {
                     // TODO: This should be deduplicated into a new function for the other variable handling as well
@@ -860,15 +851,14 @@ private async Task FetchStackFramesAsync(string scriptNameOverride)
                         : (entry.Value as PSVariable).Value;
                     var variableDetails = new VariableDetails(entry.Key.ToString(), psVarValue) { Id = nextVariableId++ };
                     variables.Add(variableDetails);
-                    localVariables.Children.Add(variableDetails.Name, variableDetails);
 
                     if (AddToAutoVariables(new PSObject(entry.Value), scope: null))
                     {
                         autoVariables.Children.Add(variableDetails.Name, variableDetails);
                     }
                 }
 
-                var stackFrameDetailsEntry = StackFrameDetails.Create(callStackFrame, autoVariables, localVariables, workspaceRootPath: _psesHost.InitialWorkingDirectory);
+                var stackFrameDetailsEntry = StackFrameDetails.Create(callStackFrame, autoVariables);
 
                 string stackFrameScriptPath = stackFrameDetailsEntry.ScriptPath;
                 if (scriptNameOverride is not null &&

src/PowerShellEditorServices/Services/DebugAdapter/Debugging/StackFrameDetails.cs

@@ -64,11 +64,6 @@ internal class StackFrameDetails
         /// </summary>
         public VariableContainerDetails AutoVariables { get; private set; }
 
-        /// <summary>
-        /// Gets or sets the VariableContainerDetails that contains the local variables.
-        /// </summary>
-        public VariableContainerDetails LocalVariables { get; private set; }
-
         #endregion
 
         #region Constructors
@@ -93,14 +88,9 @@ internal class StackFrameDetails
         /// <returns>A new instance of the StackFrameDetails class.</returns>
         static internal StackFrameDetails Create(
             PSObject callStackFrameObject,
-            VariableContainerDetails autoVariables,
-            VariableContainerDetails localVariables,
-            string workspaceRootPath = null)
+            VariableContainerDetails autoVariables)
         {
-            string moduleId = string.Empty;
             var isExternal = false;
-
-            var invocationInfo = callStackFrameObject.Properties["InvocationInfo"]?.Value as InvocationInfo;
             string scriptPath = (callStackFrameObject.Properties["ScriptName"].Value as string) ?? NoFileScriptPath;
             int startLineNumber = (int)(callStackFrameObject.Properties["ScriptLineNumber"].Value ?? 0);
 
@@ -122,7 +112,6 @@ static internal StackFrameDetails Create(
                 StartColumnNumber = 0,   // Column number isn't given in PowerShell stack frames
                 EndColumnNumber = 0,
                 AutoVariables = autoVariables,
-                LocalVariables = localVariables,
                 IsExternalCode = isExternal
             };
         }