Eliminate allocation in parse method by removing foreach loop (enumea…

…tor)
Yortw · Jul 30, 2017 · 948cb0c · 948cb0c
1 parent 2c2e42d
commit 948cb0c
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Showing 2 changed files with 15 additions and 25 deletions.
diff --git a/src/Xid.Net.Tests/Xid_New_Tests.cs b/src/Xid.Net.Tests/Xid_New_Tests.cs
@@ -65,8 +65,6 @@ public void Xid_New_GeneratesUniqueXids()
 		public void Xid_New_GeneratesUniqueXids_Threaded()
 		{
 			int maxIterations = 10000000;
-			if (IntPtr.Size > 4)
-				maxIterations = 40000000; //Moa tests on 64 bit! (32 bit runs out of contiguous memory for dictionary)
 
 			int threadCount = Math.Max(2, Environment.ProcessorCount);
 			int step = maxIterations / threadCount;

diff --git a/src/Xid.Shared/Xid.cs b/src/Xid.Shared/Xid.cs
@@ -153,8 +153,10 @@ public static bool TryParse(string encodedXid, out Xid xid)
 
 		private static bool ContainsOnlyValidXidChars(string encodedXid)
 		{
-			foreach (char c in encodedXid)
+			Char c;
+			for (int i = 0; i < encodedXid.Length; i++)
 			{
+				c = encodedXid[i];
 				if (c < '0' || (c > '9' && c < 'a') || c > 'v')
 				{
 					return false;
@@ -167,28 +169,18 @@ private static byte[] InternalParse(string xidStr)
 		{
 			byte[] retVal = new byte[Xid.Length];
 
-			////TODO: This is shitty when called from tryparse.
-			////One of the main reasons for tryparse is to avoid the overhead
-			////of exceptions. Can we do better? 
-			//try
-			//{
-				retVal[0] = (byte)(DecodeMap[xidStr[0]] << 3 | DecodeMap[xidStr[1]] >> 2);
-				retVal[1] = (byte)(DecodeMap[xidStr[1]] << 6 | DecodeMap[xidStr[2]] << 1 | DecodeMap[xidStr[3]] >> 4);
-				retVal[2] = (byte)(DecodeMap[xidStr[3]] << 4 | DecodeMap[xidStr[4]] >> 1);
-				retVal[3] = (byte)(DecodeMap[xidStr[4]] << 7 | DecodeMap[xidStr[5]] << 2 | DecodeMap[xidStr[6]] >> 3);
-				retVal[4] = (byte)(DecodeMap[xidStr[6]] << 5 | DecodeMap[xidStr[7]]);
-				retVal[5] = (byte)(DecodeMap[xidStr[8]] << 3 | DecodeMap[xidStr[9]] >> 2);
-				retVal[6] = (byte)(DecodeMap[xidStr[9]] << 6 | DecodeMap[xidStr[10]] << 1 | DecodeMap[xidStr[11]] >> 4);
-				retVal[7] = (byte)(DecodeMap[xidStr[11]] << 4 | DecodeMap[xidStr[12]] >> 1);
-				retVal[8] = (byte)(DecodeMap[xidStr[12]] << 7 | DecodeMap[xidStr[13]] << 2 | DecodeMap[xidStr[14]] >> 3);
-				retVal[9] = (byte)(DecodeMap[xidStr[14]] << 5 | DecodeMap[xidStr[15]]);
-				retVal[10] = (byte)(DecodeMap[xidStr[16]] << 3 | DecodeMap[xidStr[17]] >> 2);
-				retVal[11] = (byte)(DecodeMap[xidStr[17]] << 6 | DecodeMap[xidStr[18]] << 1 | DecodeMap[xidStr[19]] >> 4);
-			//}
-			//catch (IndexOutOfRangeException)
-			//{
-			//	return null;
-			//}
+			retVal[0] = (byte)(DecodeMap[xidStr[0]] << 3 | DecodeMap[xidStr[1]] >> 2);
+			retVal[1] = (byte)(DecodeMap[xidStr[1]] << 6 | DecodeMap[xidStr[2]] << 1 | DecodeMap[xidStr[3]] >> 4);
+			retVal[2] = (byte)(DecodeMap[xidStr[3]] << 4 | DecodeMap[xidStr[4]] >> 1);
+			retVal[3] = (byte)(DecodeMap[xidStr[4]] << 7 | DecodeMap[xidStr[5]] << 2 | DecodeMap[xidStr[6]] >> 3);
+			retVal[4] = (byte)(DecodeMap[xidStr[6]] << 5 | DecodeMap[xidStr[7]]);
+			retVal[5] = (byte)(DecodeMap[xidStr[8]] << 3 | DecodeMap[xidStr[9]] >> 2);
+			retVal[6] = (byte)(DecodeMap[xidStr[9]] << 6 | DecodeMap[xidStr[10]] << 1 | DecodeMap[xidStr[11]] >> 4);
+			retVal[7] = (byte)(DecodeMap[xidStr[11]] << 4 | DecodeMap[xidStr[12]] >> 1);
+			retVal[8] = (byte)(DecodeMap[xidStr[12]] << 7 | DecodeMap[xidStr[13]] << 2 | DecodeMap[xidStr[14]] >> 3);
+			retVal[9] = (byte)(DecodeMap[xidStr[14]] << 5 | DecodeMap[xidStr[15]]);
+			retVal[10] = (byte)(DecodeMap[xidStr[16]] << 3 | DecodeMap[xidStr[17]] >> 2);
+			retVal[11] = (byte)(DecodeMap[xidStr[17]] << 6 | DecodeMap[xidStr[18]] << 1 | DecodeMap[xidStr[19]] >> 4);
 
 			return retVal;
 		}