Adds an optimization in case when a single number is passed to encode (#49)

Author: dompagoj

src/Hashids.net/Hashids.cs

@@ -142,6 +142,15 @@ private static void InitCharArrays(string alphabet, string seps, ReadOnlySpan<ch
             }
         }
 
+#if NETCOREAPP3_1_OR_GREATER
+        /// <summary>
+        /// Encodes the provided number into a hashed string
+        /// </summary>
+        /// <param name="number">the number</param>
+        /// <returns>the hashed string</returns>
+        public string Encode(int number) => EncodeLong(number);
+#endif
+
         /// <summary>
         /// Encodes the provided numbers into a hash string.
         /// </summary>
@@ -156,6 +165,20 @@ private static void InitCharArrays(string alphabet, string seps, ReadOnlySpan<ch
         /// <returns>Encoded hash string.</returns>
         public virtual string Encode(IEnumerable<int> numbers) => Encode(numbers.ToArray());
 
+#if NETCOREAPP3_1_OR_GREATER
+        /// <summary>
+        /// Encodes the provided number into a hashed string
+        /// </summary>
+        /// <param name="number">the number</param>
+        /// <returns>the hashed string</returns>
+        public string EncodeLong(long number)
+        {
+            ReadOnlySpan<long> span = stackalloc[] { number };
+
+            return GenerateHashFrom(span);
+        }
+#endif
+
         /// <summary>
         /// Encodes the provided numbers into a hash string.
         /// </summary>
@@ -268,7 +291,7 @@ private string GenerateHashFrom(ReadOnlySpan<long> numbers)
                     {
                         Array.Copy(alphabet, 0, shuffleBuffer, startIndex, length);
                     }
-                    
+
                     ConsistentShuffle(alphabet, _alphabet.Length, shuffleBuffer, _alphabet.Length);
                     var hashLength = BuildReversedHash(number, alphabet, hashBuffer);
 
@@ -375,7 +398,7 @@ private long[] GetNumbersFrom(string hash)
 
             if (lottery == '\0') /* default(char) == '\0' */
                 return Array.Empty<long>();
-                
+
             hashBreakdown = hashBreakdown.Substring(1);
 
             hashArray = hashBreakdown.Split(_seps, StringSplitOptions.RemoveEmptyEntries);
@@ -447,4 +470,4 @@ private static void ConsistentShuffle(char[] alphabet, int alphabetLength, ReadO
             }
         }
     }
-}
+}

src/Hashids.net/IHashids.cs

@@ -29,6 +29,15 @@ public interface IHashids
         /// <returns>the hex string</returns>
         string DecodeHex(string hash);
 
+#if NETCOREAPP3_1_OR_GREATER
+        /// <summary>
+        /// Encodes the provided number into a hashed string
+        /// </summary>
+        /// <param name="number">the number</param>
+        /// <returns>the hashed string</returns>
+        string Encode(int number);
+#endif
+
         /// <summary>
         /// Encodes the provided numbers into a hashed string
         /// </summary>
@@ -43,6 +52,15 @@ public interface IHashids
         /// <returns>the hashed string</returns>
         string Encode(IEnumerable<int> numbers);
 
+#if NETCOREAPP3_1_OR_GREATER
+        /// <summary>
+        /// Encodes the provided number into a hashed string
+        /// </summary>
+        /// <param name="number">the number</param>
+        /// <returns>the hashed string</returns>
+        string EncodeLong(long number);
+#endif
+
         /// <summary>
         /// Encodes the provided numbers into a hashed string
         /// </summary>

test/Hashids.net.benchmark/Program.cs

@@ -43,6 +43,20 @@ public void RoundtripHex()
                 var encodedValue = _hashids.EncodeHex(_hex);
                 var decodedValue = _hashids.DecodeHex(encodedValue);
             }
+
+            [Benchmark]
+            public void SingleNumber()
+            {
+                var encoded = _hashids.Encode(5);
+                var encodeLong = _hashids.EncodeLong(5);
+            }
+
+            [Benchmark]
+            public void SingleNumberAsParams()
+            {
+                var encoded = _hashids.Encode(new []{ 1 });
+                var encodedLong = _hashids.EncodeLong(new []{ (long)1 });
+            }
         }
     }
-}
+}

test/Hashids.net.test/GeneralTests.cs

@@ -338,4 +338,4 @@ public void PublicMethodsCanBeMocked()
             mock.Object.Encode(new[] { 1 }).Should().Be("It works");
         }
     }
-}
+}