From 33327aa1a951a1d0717b39f8f71356f09eb7bd6e Mon Sep 17 00:00:00 2001 From: Bond_009 Date: Thu, 22 Apr 2021 12:31:47 +0200 Subject: [PATCH] Improve fast path of ManagedFileSystem.GetValidFilename | Method | Data | Mean | Error | StdDev | Median | Gen 0 | Gen 1 | Gen 2 | Allocated | |---------------------------- |-------------- |------------:|----------:|----------:|------------:|-------:|------:|------:|----------:| | GetValidFilenameBench | AC/DCKD/A | 52.29 ns | 0.537 ns | 0.448 ns | 52.35 ns | 0.0255 | - | - | 80 B | | GetValidFilenameOldBench | AC/DCKD/A | 86.68 ns | 1.205 ns | 1.127 ns | 86.33 ns | 0.0587 | - | - | 184 B | | GetValidFilenameWinBench | AC/DCKD/A | 448.55 ns | 1.228 ns | 1.088 ns | 448.33 ns | 0.0505 | - | - | 160 B | | GetValidFilenameOldWinBench | AC/DCKD/A | 865.21 ns | 5.734 ns | 5.083 ns | 866.60 ns | 0.0839 | - | - | 264 B | | GetValidFilenameBench | ValidFileName | 16.00 ns | 0.234 ns | 0.207 ns | 16.02 ns | 0.0102 | - | - | 32 B | | GetValidFilenameOldBench | ValidFileName | 100.66 ns | 1.255 ns | 1.174 ns | 101.21 ns | 0.0587 | - | - | 184 B | | GetValidFilenameWinBench | ValidFileName | 116.60 ns | 1.624 ns | 1.519 ns | 116.88 ns | 0.0356 | - | - | 112 B | | GetValidFilenameOldWinBench | ValidFileName | 1,052.66 ns | 18.077 ns | 33.056 ns | 1,037.25 ns | 0.0839 | - | - | 264 B | --- .../IO/ManagedFileSystem.cs | 27 +++++++++---------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/Emby.Server.Implementations/IO/ManagedFileSystem.cs b/Emby.Server.Implementations/IO/ManagedFileSystem.cs index 0d72cb00f6..df973f9715 100644 --- a/Emby.Server.Implementations/IO/ManagedFileSystem.cs +++ b/Emby.Server.Implementations/IO/ManagedFileSystem.cs @@ -302,28 +302,27 @@ namespace Emby.Server.Implementations.IO /// The filename is null. public string GetValidFilename(string filename) { + var invalid = Path.GetInvalidFileNameChars(); + var first = filename.IndexOfAny(invalid); + if (first == -1) + { + // Fast path for clean strings + return filename; + } + return string.Create( filename.Length, - filename, + (filename, invalid, first), (chars, state) => { - state.AsSpan().CopyTo(chars); + state.filename.AsSpan().CopyTo(chars); - var invalid = Path.GetInvalidFileNameChars(); - - var first = state.AsSpan().IndexOfAny(invalid); - if (first == -1) - { - // Fast path for clean strings - return; - } - - chars[first++] = ' '; + chars[state.first++] = ' '; var len = chars.Length; - foreach (var c in invalid) + foreach (var c in state.invalid) { - for (int i = first; i < len; i++) + for (int i = state.first; i < len; i++) { if (chars[i] == c) {