Merge pull request #365 from mk3008/364-supports-parsing-of-large-values-queries

Supports parsing of large value queries

Author: mk3008

src/Carbunql/CommandTextBuilder.cs

@@ -75,11 +75,6 @@ public string Execute(IEnumerable<Token> tokens)
 				{
 					Logger?.Invoke($"decrement indent and line break on before : {t.Text}");
 					Level = lv;
-
-					//NOTE:
-					//Remembering indentation has a big impact on performance.
-					//Improves performance by deleting the cache of indentation levels when the indentation is no longer present.
-					if (Level == 0) IndentLevels.Clear();
 					sb.Append(GetLineBreakText());
 				}
 				else
@@ -138,7 +133,16 @@ private string GetTokenTextCore(Token token)
 
 	private string GetLineBreakText()
 	{
+		//init previous token
 		PrevToken = null;
+
+		// NOTE:
+		// For performance improvement, remove unnecessary indent information
+		// However, keep one for the starting position of brackets
+		var startIndent = IndentLevels.Where(x => x.Level == Level).FirstOrDefault();
+		IndentLevels.RemoveAll(x => Level <= x.Level && x != startIndent);
+
+		//line break
 		if (!SpacerCache.ContainsKey(Level))
 		{
 			SpacerCache[Level] = (Level * 4).ToSpaceString();

test/Carbunql.Analysis.Test/StackOverFlowTest.cs

@@ -16,10 +16,10 @@ public StackOverFlowTest(ITestOutputHelper output)
 	public void Union_50k()
 	{
 		var sb = new StringBuilder();
-		sb.Append("select 1");
+		sb.Append("select 1,2,3,4,5,6,7,8,9,10");
 		for (int i = 0; i < 50000; i++)
 		{
-			sb.Append(" union all select 1");
+			sb.Append(" union all select 1,2,3,4,5,6,7,8,9,10");
 		}
 
 		var exception = Record.Exception(() =>
@@ -32,4 +32,25 @@ public void Union_50k()
 
 		Assert.Null(exception);
 	}
+
+	[Fact]
+	public void Values_50k()
+	{
+		var sb = new StringBuilder();
+		sb.Append("values (1,2,3,4,5,6,7,8,9,10)");
+		for (int i = 0; i < 50000; i++)
+		{
+			sb.Append(", (1,2,3,4,5,6,7,8,9,10)");
+		}
+
+		var exception = Record.Exception(() =>
+		{
+			var vq = new ValuesQuery(sb.ToString());
+			vq.GetTokens();
+
+			Output.WriteLine(vq.ToText());
+		});
+
+		Assert.Null(exception);
+	}
 }