CommandFactory Improvements

- string operation improvements

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CommandFactory.cs

@@ -19,8 +19,6 @@ namespace Xtensive.Orm.Providers
   /// </summary>
   public class CommandFactory
   {
-    private const string ParameterNameFormat = "{0}{1}";
-    private const string RowFilterParameterNameFormat = "{0}_{1}_{2}";
     private const string DefaultParameterNamePrefix = "p0_";
     private const int LobBlockSize = ushort.MaxValue;
 
@@ -58,7 +56,7 @@ public virtual IEnumerable<CommandPart> CreatePersistParts(SqlPersistTask task,
         foreach (var binding in request.ParameterBindings) {
           var parameterValue = GetParameterValue(task, binding);
           if (binding.BindingType==PersistParameterBindingType.VersionFilter && IsHandledLikeNull(parameterValue)) {
-            configuration.AlternativeBranches.Add(binding);
+            _ = configuration.AlternativeBranches.Add(binding);
           }
           else {
             var parameterName = GetParameterName(parameterNamePrefix, ref parameterIndex);
@@ -106,14 +104,14 @@ public virtual CommandPart CreateQueryPart(IQueryRequest request, string paramet
         case QueryParameterBindingType.SmartNull:
           // replacing "x = @p" with "x is null" when @p = null (or empty string in case of Oracle)
           if (IsHandledLikeNull(parameterValue)) {
-            configuration.AlternativeBranches.Add(binding);
+            _ = configuration.AlternativeBranches.Add(binding);
             continue;
           }
           break;
         case QueryParameterBindingType.BooleanConstant:
           // expanding true/false parameters to constants to help query optimizer with branching
           if ((bool) parameterValue)
-            configuration.AlternativeBranches.Add(binding);
+            _ = configuration.AlternativeBranches.Add(binding);
           continue;
         case QueryParameterBindingType.LimitOffset:
           // not parameter, just inlined constant
@@ -123,27 +121,28 @@ public virtual CommandPart CreateQueryPart(IQueryRequest request, string paramet
           // Like "LimitOffset" but we handle zero value specially
           // We replace value with 1 and activate special branch that evaluates "where" part to "false"
           var stringValue = parameterValue.ToString();
-          if (stringValue=="0") {
+          if (stringValue.Equals("0", StringComparison.Ordinal)) {
             configuration.PlaceholderValues.Add(binding, "1");
-            configuration.AlternativeBranches.Add(binding);
+            _ = configuration.AlternativeBranches.Add(binding);
           }
-          else
+          else {
             configuration.PlaceholderValues.Add(binding, stringValue);
+          }
           continue;
         case QueryParameterBindingType.RowFilter:
           var filterData = (List<Tuple>) parameterValue;
-          var rowTypeMapping = ((QueryRowFilterParameterBinding) binding).RowTypeMapping;
-          if (filterData==null) {
-            configuration.AlternativeBranches.Add(binding);
+          if (filterData is null) {
+            _ = configuration.AlternativeBranches.Add(binding);
             continue;
           }
+          var rowTypeMapping = ((QueryRowFilterParameterBinding) binding).RowTypeMapping;
           var commonPrefix = GetParameterName(parameterNamePrefix, ref parameterIndex);
-          var filterValues = new List<string[]>();
-          for (int tupleIndex = 0; tupleIndex < filterData.Count; tupleIndex++) {
+          var filterValues = new List<string[]>(filterData.Count);
+          for (int tupleIndex = 0, overallCount = filterData.Count; tupleIndex < overallCount; tupleIndex++) {
             var tuple = filterData[tupleIndex];
             var parameterReferences = new string[tuple.Count];
-            for (int fieldIndex = 0; fieldIndex < tuple.Count; fieldIndex++) {
-              var name = string.Format(RowFilterParameterNameFormat, commonPrefix, tupleIndex, fieldIndex);
+            for (int fieldIndex = 0, fieldCount = tuple.Count; fieldIndex < fieldCount; fieldIndex++) {
+              var name = $"{commonPrefix}_{tupleIndex.ToString("G")}_{fieldIndex.ToString("G")}";
               var value = tuple.GetValueOrDefault(fieldIndex);
               parameterReferences[fieldIndex] = Driver.BuildParameterReference(name);
               AddRegularParameter(result, rowTypeMapping[fieldIndex], name, value);
@@ -156,7 +155,7 @@ public virtual CommandPart CreateQueryPart(IQueryRequest request, string paramet
           throw new ArgumentOutOfRangeException("binding.BindingType");
         }
         // regular case -> just adding the parameter
-        string parameterName = GetParameterName(parameterNamePrefix, ref parameterIndex);
+        var parameterName = GetParameterName(parameterNamePrefix, ref parameterIndex);
         configuration.PlaceholderValues.Add(binding, Driver.BuildParameterReference(parameterName));
         AddParameter(result, binding, parameterName, parameterValue);
       }
@@ -183,12 +182,12 @@ private static object GetParameterValue(QueryParameterBinding binding, Parameter
     private object GetParameterValue(SqlPersistTask task, PersistParameterBinding binding)
     {
       switch (binding.BindingType) {
-      case PersistParameterBindingType.Regular:
-        return task.Tuple.GetValueOrDefault(binding.FieldIndex);
-      case PersistParameterBindingType.VersionFilter:
-        return task.OriginalTuple.GetValueOrDefault(binding.FieldIndex);
-      default:
-        throw new ArgumentOutOfRangeException("binding.Source");
+        case PersistParameterBindingType.Regular:
+          return task.Tuple.GetValueOrDefault(binding.FieldIndex);
+        case PersistParameterBindingType.VersionFilter:
+          return task.OriginalTuple.GetValueOrDefault(binding.FieldIndex);
+        default:
+          throw new ArgumentOutOfRangeException("binding.Source");
       }
     }
 
@@ -262,7 +261,7 @@ private void AddParameter(
 
     private string GetParameterName(string prefix, ref int index)
     {
-      var result = string.Format(ParameterNameFormat, prefix, index);
+      var result = $"{prefix}{index.ToString("G")}"; //leave ToString(). it is faster
       index++;
       return result;
     }

Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/CursorCommandFactory.cs

@@ -16,14 +16,11 @@ namespace Xtensive.Orm.Providers
   /// </summary>
   public class CursorCommandFactory : CommandFactory
   {
-    private const string CursorParameterNameFormat = "{0}c";
-    private const string StatementFormat = "OPEN :{0} FOR {1}";
-
     public override CommandPart CreateQueryPart(IQueryRequest request, string parameterNamePrefix, ParameterContext parameterContext)
     {
       var part = base.CreateQueryPart(request, parameterNamePrefix, parameterContext);
-      var parameterName = string.Format(CursorParameterNameFormat, parameterNamePrefix);
-      part.Statement = string.Format(StatementFormat, parameterName, part.Statement);
+      var parameterName = $"{parameterNamePrefix}c";
+      part.Statement = $"OPEN :{parameterName} FOR {part.Statement}";
       var parameter = Connection.CreateCursorParameter();
       parameter.ParameterName = parameterName;
       part.Parameters.Add(parameter);