Bepis Comments - Answer Overflow

Bepis

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

| Method                      | TestString | Mean      | Error     | StdDev   |
|---------------------------- |----------- |----------:|----------:|---------:|
| BareImplementation          | benchmarks |  25.90 ns |  4.169 ns | 2.481 ns |
| BareImplementationWithCheck | benchmarks |  16.13 ns |  2.335 ns | 1.389 ns |
| AsciiToLower                | benchmarks |  40.56 ns |  1.616 ns | 0.845 ns |
| ToLowerInvariant            | benchmarks |  47.25 ns |  0.531 ns | 0.278 ns |
| DeferredCreation            | benchmarks | 136.06 ns |  9.650 ns | 5.743 ns |
| BareImplementation          | BenchMarks |  21.46 ns |  1.496 ns | 0.890 ns |
| BareImplementationWithCheck | BenchMarks |  26.97 ns |  1.720 ns | 1.023 ns |
| AsciiToLower                | BenchMarks |  40.60 ns |  1.062 ns | 0.555 ns |
| ToLowerInvariant            | BenchMarks |  47.16 ns |  0.902 ns | 0.472 ns |
| DeferredCreation            | BenchMarks | 147.46 ns | 10.854 ns | 5.677 ns |

| Method                      | TestString | Mean      | Error     | StdDev   |
|---------------------------- |----------- |----------:|----------:|---------:|
| BareImplementation          | benchmarks |  25.90 ns |  4.169 ns | 2.481 ns |
| BareImplementationWithCheck | benchmarks |  16.13 ns |  2.335 ns | 1.389 ns |
| AsciiToLower                | benchmarks |  40.56 ns |  1.616 ns | 0.845 ns |
| ToLowerInvariant            | benchmarks |  47.25 ns |  0.531 ns | 0.278 ns |
| DeferredCreation            | benchmarks | 136.06 ns |  9.650 ns | 5.743 ns |
| BareImplementation          | BenchMarks |  21.46 ns |  1.496 ns | 0.890 ns |
| BareImplementationWithCheck | BenchMarks |  26.97 ns |  1.720 ns | 1.023 ns |
| AsciiToLower                | BenchMarks |  40.60 ns |  1.062 ns | 0.555 ns |
| ToLowerInvariant            | BenchMarks |  47.16 ns |  0.902 ns | 0.472 ns |
| DeferredCreation            | BenchMarks | 147.46 ns | 10.854 ns | 5.677 ns |

    public class LowercaseBenchmark
    {
        [Params("benchmarks", "BenchMarks")]
        public string TestString { get; set; }
        
        [Benchmark]
        public string BareImplementation()
        {
            ReadOnlySpan<char> span = TestString;
            Span<char> chars = stackalloc char[span.Length];

            for (int i = 0; i < span.Length; i++)
            {
                char c = span[i];
                chars[i] = (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
            }

            return new string(chars);
        }
        
        [Benchmark]
        public string BareImplementationWithCheck()
        {
            ReadOnlySpan<char> span = TestString;

            bool hasUppercase = false;
            for (int i = 0; i < span.Length; i++)
            {
                char c = span[i];
                if (c >= 'A' && c <= 'Z')
                {
                    hasUppercase = true;
                    break;
                }
            }

            if (!hasUppercase)
                return new string(span);

            Span<char> chars = stackalloc char[span.Length];

            for (int i = 0; i < span.Length; i++)
            {
                char c = span[i];
                chars[i] = (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
            }

            return new string(chars);
        }
        
        [Benchmark]
        public string AsciiToLower()
        {
            ReadOnlySpan<char> span = TestString;
            Span<char> chars = stackalloc char[span.Length];
        
            Ascii.ToLower(span, chars, out _);

            return new string(chars);
        }
        
        [Benchmark]
        public string ToLowerInvariant()
        {
            ReadOnlySpan<char> span = TestString;
            Span<char> chars = stackalloc char[span.Length];
        
            span.ToLowerInvariant(chars);

            return new string(chars);
        }
        
        [Benchmark]
        public string DeferredCreation()
        {
            ReadOnlySpan<char> span = TestString;

            unsafe
            {
                var ptr = &span;
                return String.Create(span.Length, (nint)ptr, static (buffer, ptr) =>
                {
                    var span = *(ReadOnlySpan<char>*)ptr;
                    for (int i = 0; i < span.Length; i++)
                    {
                        char c = span[i];
                        buffer[i] = (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
                    }
                });
            }
        }
    }

    public class LowercaseBenchmark
    {
        [Params("benchmarks", "BenchMarks")]
        public string TestString { get; set; }
        
        [Benchmark]
        public string BareImplementation()
        {
            ReadOnlySpan<char> span = TestString;
            Span<char> chars = stackalloc char[span.Length];

            for (int i = 0; i < span.Length; i++)
            {
                char c = span[i];
                chars[i] = (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
            }

            return new string(chars);
        }
        
        [Benchmark]
        public string BareImplementationWithCheck()
        {
            ReadOnlySpan<char> span = TestString;

            bool hasUppercase = false;
            for (int i = 0; i < span.Length; i++)
            {
                char c = span[i];
                if (c >= 'A' && c <= 'Z')
                {
                    hasUppercase = true;
                    break;
                }
            }

            if (!hasUppercase)
                return new string(span);

            Span<char> chars = stackalloc char[span.Length];

            for (int i = 0; i < span.Length; i++)
            {
                char c = span[i];
                chars[i] = (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
            }

            return new string(chars);
        }
        
        [Benchmark]
        public string AsciiToLower()
        {
            ReadOnlySpan<char> span = TestString;
            Span<char> chars = stackalloc char[span.Length];
        
            Ascii.ToLower(span, chars, out _);

            return new string(chars);
        }
        
        [Benchmark]
        public string ToLowerInvariant()
        {
            ReadOnlySpan<char> span = TestString;
            Span<char> chars = stackalloc char[span.Length];
        
            span.ToLowerInvariant(chars);

            return new string(chars);
        }
        
        [Benchmark]
        public string DeferredCreation()
        {
            ReadOnlySpan<char> span = TestString;

            unsafe
            {
                var ptr = &span;
                return String.Create(span.Length, (nint)ptr, static (buffer, ptr) =>
                {
                    var span = *(ReadOnlySpan<char>*)ptr;
                    for (int i = 0; i < span.Length; i++)
                    {
                        char c = span[i];
                        buffer[i] = (c >= 'A' && c <= 'Z') ? (char)(c + 32) : c;
                    }
                });
            }
        }
    }

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

so it seems that ToLowerInvariant is faster in this context but not in the other

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

even more interestingly, it avgs at around 550ms

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

lets take a look

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

things that generally feel like they should perform better, don't

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

yes i think that sums up the last 4 or so hours i've been staring at this

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

this is actually slower as well somehow. for a 5MB batch of documents its avg is 500ms, the direct copy to stackalloc and checking each char avg is about 450ms

30 replies

CC#

•Created by Bepis on 10/19/2024 in #help

Is there a faster way of splitting strings?

30 replies

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