Implemented FnvHash

src/Sentry/Internal/FnvHash.cs

@@ -0,0 +1,43 @@
+namespace Sentry.Internal;
+
+/// <summary>
+/// FNV is a non-cryptographic hash.
+///
+/// See https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV_hash_parameters
+/// </summary>
+/// <remarks>
+/// We use a struct to avoid heap allocations.
+/// </remarks>
+internal struct FnvHash
+{
+    public FnvHash()
+    {
+    }
+
+    private const int Offset = unchecked((int)2166136261);
+    private const int Prime = 16777619;
+
+    private int HashCode { get; set; } = Offset;
+
+    private void Combine(byte data)
+    {
+        unchecked
+        {
+            HashCode ^= data;
+            HashCode *= Prime;
+        }
+    }
+
+    private static int ComputeHash(byte[] data)
+    {
+        var result = new FnvHash();
+        foreach (var b in data)
+        {
+            result.Combine(b);
+        }
+
+        return result.HashCode;
+    }
+
+    public static int ComputeHash(string data) => ComputeHash(Encoding.UTF8.GetBytes(data));
+}

test/Sentry.Tests/Internals/FnvHashTests.cs

@@ -0,0 +1,24 @@
+namespace Sentry.Tests.Internals;
+
+public class FnvHashTests
+{
+    [Theory]
+    [InlineData("", 2_166_136_261)]
+    [InlineData("h", 3_977_000_791)]
+    [InlineData("he", 1_547_363_254)]
+    [InlineData("hel", 179_613_742)]
+    [InlineData("hell", 477_198_310)]
+    [InlineData("hello", 1_335_831_723)]
+    [InlineData("hello ", 3_801_292_497)]
+    [InlineData("hello w", 1_402_552_146)]
+    [InlineData("hello wo", 3_611_200_775)]
+    [InlineData("hello wor", 1_282_977_583)]
+    [InlineData("hello worl", 2_767_971_961)]
+    [InlineData("hello world", 3_582_672_807)]
+    public void ComputeHash_WithString_ReturnsExpected(string input, uint expected)
+    {
+        var actual = FnvHash.ComputeHash(input);
+
+        Assert.Equal(unchecked((int)expected), actual);
+    }
+}