Merge pull request #2 from DI20ID/master

added PatternScan ALittleBitNaiveFor

Author: uberhalit

PatternScanBench/Implementations/PatternScanALittleBitNaiveFor.cs

@@ -0,0 +1,81 @@
+using System.Collections.Generic;
+
+namespace PatternScanBench.Implementations
+{
+    /// <summary>
+    /// Pattern scan implementation 'ALittleBitNaiveFor' - by DI20ID
+    /// https://github.com/DI20ID
+    /// </summary>
+    internal class PatternScanALittleBitNaiveFor : PatternScanAlgorithm
+    {
+        /// <summary>
+        /// Authors name.
+        /// </summary>
+        internal override string Creator => "DI20ID";
+        internal PatternScanALittleBitNaiveFor() { }
+
+        /// <summary>
+        /// Initializes a new 'PatternScanTest'.
+        /// </summary>
+        /// <param name="cbMemory">The byte array to scan.</param>
+        /// <returns>An optional string to display next to benchmark results.</returns>
+        internal override string Init(in byte[] cbMemory)
+        {
+            return "";
+        }
+
+        /// <summary>
+        /// Returns address of pattern using 'ALittleBitNaiveFor' implementation by DI20ID. Can match 0.
+        /// </summary>
+        /// <param name="cbMemory">The byte array to scan.</param>
+        /// <param name="cbPattern">The byte pattern to look for, wildcard positions are replaced by 0.</param>
+        /// <param name="szMask">A string that determines how pattern should be matched, 'x' is match, '?' acts as wildcard.</param>
+        /// <returns>-1 if pattern is not found.</returns>
+        internal override long FindPattern(in byte[] cbMemory, in byte[] cbPattern, string szMask)
+        {
+            long ix;
+            int iy;
+
+            List<byte> ls = new List<byte>();
+            List<int> ini = new List<int>();
+
+            int dataLength = cbMemory.Length - cbPattern.Length;
+
+            for (iy = cbPattern.Length - 1; iy > -1; iy--)
+            {
+                if (szMask[iy] == 'x')
+                {
+
+                    ls.Add(cbPattern[iy]);
+                    ini.Add(iy);
+                }
+            }
+
+            byte[] arr = ls.ToArray();
+            byte[] arr1 = new byte[arr.Length];
+
+            for (ix = 0; ix < dataLength; ix++)
+            {
+                if (arr[arr.Length - 1] == cbMemory[ix])
+                {
+                    bool check = true;
+
+                    for (iy = arr.Length - 1; iy > -1; iy--)
+                    {
+                        if (arr[iy] == cbMemory[ix + ini[iy]])
+                            continue;
+                        check = false;
+                        break;
+                    }
+
+                    if (check)
+                    {
+                        return ix;
+                    }
+                }
+            }
+
+            return -1;
+        }
+    }
+}

PatternScanBench/PatternScanBench.csproj

@@ -55,6 +55,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Implementations\PatternScanALittleBitNaiveFor.cs" />
     <Compile Include="Implementations\PatternScanNaiveFor.cs" />
     <Compile Include="Implementations\PatternScanNaiveLINQ.cs" />
     <Compile Include="Implementations\PatternScanBoyerMooreHorspool.cs" />

PatternScanBench/Program.cs

@@ -16,6 +16,7 @@ Add your implementation here
          */
         static readonly Dictionary<string, PatternScanAlgorithm> PATTERN_SCAN_ALGORITHMS = new Dictionary<string, PatternScanAlgorithm>
         {
+            { "ALittleBitNaiveFor", new PatternScanALittleBitNaiveFor() }, // by DI20ID
             { "LearnMore", new PatternScanLearnMore() }, // by learn_more
             { "Trainer", new PatternScanTrainer() }, // by erfg12
             { "NaiveSIMD", new PatternScanNaiveSIMD() }, // by uberhalit