update:

1. improve symbol loading performance
2. imrpove fuzzy search performance

doc/roadmap/Feature Update.md

@@ -0,0 +1,23 @@
+## Custom Ignore Variables Pattern
+
+when load twincat project variables, sometimes it's nice to ignore some variables, such as:
+
+![](assets/Pasted%20image%2020250122154205.png)
+
+- `axis.PlcToNc.xxx`
+
+When multiple axis are used, these unnecessary variables will significantly slower the program, hence it's good to provide a filter to remove such variables. Moreover, it's better to provide a custom filter (of cource some default rules are provides)?
+
+
+
+## Remove Multiple Variables
+
+when a variable is passed into a function block, whether it's by `VAR_INPUT` or `VAR_IN_OUT`, the twincat ads api will return handles for the variable out and in the function block, although they are basically the identical one.
+
+![](assets/Pasted%20image%2020250122154749.png)
+
+To identify the duplicated variables, notice that they have same last name:
+- `axis.NcToPlc.ActPos` => `NcToPlc.ActPos`
+- `power_motor.Axis.NcToPlc.ActPos`=>`Axis.NcToPlc.ActPos`
+
+the idea is to retain the variable with shortest name in the group of variables.

src/TwincatToolbox/Extensions/ISymbolExtension.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using TwinCAT.TypeSystem;
+
+namespace TwincatToolbox.Extensions;
+public static class ISymbolExtension
+{
+    // note: this method can cause problems if the symbol name is not unique
+    public static string GetSymbolName(this ISymbol symbol) {
+        return symbol.InstanceName.ToLower();
+    }
+}

src/TwincatToolbox/Models/SymbolInfo.cs

@@ -10,7 +10,8 @@
 
 namespace TwincatToolbox.Models;
 
-public partial class SymbolInfo(ISymbol symbol)
+// todo: ¼ì²éÕâÀïµÄ partial classÊÇ·ñÓбØÒª
+public class SymbolInfo(ISymbol symbol)
 {
     public ISymbol Symbol { get; set; } = symbol;
     public string Name => string.Join(".",

src/TwincatToolbox/Services/AdsComService.cs

@@ -11,6 +11,7 @@
 using TwinCAT.TypeSystem;
 using TwinCAT.ValueAccess;
 
+using TwincatToolbox.Extensions;
 using TwincatToolbox.Models;
 using TwincatToolbox.Services.IService;
 
@@ -56,11 +57,77 @@ public void DisconnectAdsServer() {
 
     /// <summary>
     /// 获取所有可行的Symbols
+    /// 1. 通过SymbolLoader加载所有Symbols
+    /// 2. 递归遍历所有Symbols(仅获取MAIN和GVL下的Symbols)
+    /// 3. 将Symbol转化为SymbolTree，同时执行重复项剔除
+    /// 4. 将SymbolTree转化为List<SymbolInfo>，返回
     /// </summary>
-    /// <returns>符号列表</returns>
+    /// <returns></returns>
     public List<SymbolInfo> GetAvailableSymbols() {
         var settings = new SymbolLoaderSettings(SymbolsLoadMode.VirtualTree,
-            ValueAccessMode.IndexGroupOffset);
+           ValueAccessMode.SymbolicByHandle);
+        var symbolLoader = SymbolLoaderFactory.Create(adsClient, settings);
+        var symbols = symbolLoader.Symbols;
+
+        // contains name of parent symbols, used to avoid duplicate symbols(symbolTree)
+        var symbolNameSet = new HashSet<string>();
+        var symbolList = new List<SymbolInfo>();
+
+        foreach (var symbol in symbols)
+        {
+            if (symbol.InstanceName is ("MAIN" or "GVL"))
+            {
+                LoadSymbolTreeBFS(symbol, ref symbolList);
+            }
+        }
+
+        return symbolList;
+
+        void LoadSymbolTreeBFS(ISymbol root, ref List<SymbolInfo> symbolList) {
+            var transverseOrder = new Queue<ISymbol>();
+
+            var symbolLoadQueue = new Queue<ISymbol>();
+            symbolLoadQueue.Enqueue(root);
+            symbolNameSet.Add(root.GetSymbolName());
+
+            while (symbolLoadQueue.Count > 0)
+            {
+                var currentSymbol = symbolLoadQueue.Dequeue();
+                transverseOrder.Enqueue(currentSymbol);
+                foreach (var subSymbol in currentSymbol.SubSymbols)
+                {
+                    if (!symbolNameSet.Contains(subSymbol.GetSymbolName(),
+                        StringComparer.CurrentCultureIgnoreCase))
+                    {
+                        symbolLoadQueue.Enqueue(subSymbol);
+                        symbolNameSet.Add(subSymbol.GetSymbolName());
+                    }
+                }
+            }
+
+            while (transverseOrder.Count > 0)
+            {
+                var symbol = transverseOrder.Dequeue();
+                if(symbol.SubSymbols.Count == 0)
+                {
+                    symbolList.Add(new SymbolInfo(symbol));
+                }
+            }
+
+            // remove first element, which is the root symbol(virtual symbol)
+            symbolList.RemoveAt(0);
+        }
+
+    }
+
+
+    /// <summary>
+    /// 获取所有可行的Symbols
+    /// </summary>
+    /// <returns>符号列表</returns>
+    public List<SymbolInfo> GetAvailableSymbols_bak() {
+        var settings = new SymbolLoaderSettings(SymbolsLoadMode.VirtualTree,
+            ValueAccessMode.SymbolicByHandle);
         var symbolLoader = SymbolLoaderFactory.Create(adsClient, settings);
         var symbols = symbolLoader.Symbols;
 

src/TwincatToolbox/ViewModels/DataLogViewModel.cs

@@ -97,7 +97,7 @@ private void OnGetAvailableSymbols()
             Debug.WriteLine("Ads server is not connected.");
             return;
         }
-
+        
         AvailableSymbols = _adsComService.GetAvailableSymbols();
         AvailableSymbols.Sort((a, b) => a.Name.CompareTo(b.Name));
         Debug.WriteLine("Available symbols: {0}", AvailableSymbols.Count());
@@ -132,13 +132,17 @@ public List<SymbolInfo> SearchSymbols(IList<SymbolInfo> sourceList)
     {
         if (string.IsNullOrEmpty((SearchText))) return sourceList.ToList();
         var searchResults = sourceList
-            .Where(s=>Fuzz.PartialRatio(SearchText.ToLower(), s.Name.ToLower()) > 85)
-            .ToList();
-        Debug.WriteLine("Search results: {0}", searchResults.Count());
+            .OrderByDescending(s=>GetSimilarityScore(SearchText, s))
+            .Take(20).ToList();
+        // Debug.WriteLine("Search results: {0}", searchResults.Count());
 
         return searchResults;
     }
 
+    public int GetSimilarityScore(string searchText, SymbolInfo symbolInfo) {
+        return Fuzz.PartialTokenSetRatio(searchText, symbolInfo.Name.ToLower());
+    }
+
     private void UpdateLogSymbol()
     {
         var logSearchSymbols = SearchSymbols(LogSymbols);