From 2da9f13db3d0e0e7b6ae69953a5356c98e321c92 Mon Sep 17 00:00:00 2001 From: Ben Adams Date: Mon, 5 Oct 2015 10:37:42 -0400 Subject: [PATCH] Less allocs in GenerateRequestId Case insentive base32 encoding --- .../FastHttpRequestIdentifierFeature.cs | 53 ++++++++++--------- src/Microsoft.AspNet.Hosting/project.json | 5 +- 2 files changed, 33 insertions(+), 25 deletions(-) diff --git a/src/Microsoft.AspNet.Hosting/Internal/FastHttpRequestIdentifierFeature.cs b/src/Microsoft.AspNet.Hosting/Internal/FastHttpRequestIdentifierFeature.cs index 74f7b36d6e..95e7806557 100644 --- a/src/Microsoft.AspNet.Hosting/Internal/FastHttpRequestIdentifierFeature.cs +++ b/src/Microsoft.AspNet.Hosting/Internal/FastHttpRequestIdentifierFeature.cs @@ -9,9 +9,12 @@ namespace Microsoft.AspNet.Hosting.Internal { public class FastHttpRequestIdentifierFeature : IHttpRequestIdentifierFeature { - private static readonly string _hexChars = "0123456789ABCDEF"; - // Seed the _requestId for this application instance with a random int - private static long _requestId = new Random().Next(); + // Base64 encoding - but in ascii sort order for easy text based sorting + private static readonly string _encode32Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUV"; + // Seed the _requestId for this application instance with + // the number of 100-nanosecond intervals that have elapsed since 12:00:00 midnight, January 1, 0001 + // for a roughly increasing _requestId over restarts + private static long _requestId = DateTime.UtcNow.Ticks; private string _id = null; @@ -32,29 +35,31 @@ namespace Microsoft.AspNet.Hosting.Internal } } - private static string GenerateRequestId(long id) + private static unsafe string GenerateRequestId(long id) { - // The following routine is ~33% faster than calling long.ToString() when testing in tight loops of - // 1 million iterations. - var charBuffer = new char[sizeof(long) * 2]; - charBuffer[0] = _hexChars[(int)(id >> 60) & 0x0f]; - charBuffer[1] = _hexChars[(int)(id >> 56) & 0x0f]; - charBuffer[2] = _hexChars[(int)(id >> 52) & 0x0f]; - charBuffer[3] = _hexChars[(int)(id >> 48) & 0x0f]; - charBuffer[4] = _hexChars[(int)(id >> 44) & 0x0f]; - charBuffer[5] = _hexChars[(int)(id >> 40) & 0x0f]; - charBuffer[6] = _hexChars[(int)(id >> 36) & 0x0f]; - charBuffer[7] = _hexChars[(int)(id >> 32) & 0x0f]; - charBuffer[8] = _hexChars[(int)(id >> 28) & 0x0f]; - charBuffer[9] = _hexChars[(int)(id >> 24) & 0x0f]; - charBuffer[10] = _hexChars[(int)(id >> 20) & 0x0f]; - charBuffer[11] = _hexChars[(int)(id >> 16) & 0x0f]; - charBuffer[12] = _hexChars[(int)(id >> 12) & 0x0f]; - charBuffer[13] = _hexChars[(int)(id >> 8) & 0x0f]; - charBuffer[14] = _hexChars[(int)(id >> 4) & 0x0f]; - charBuffer[15] = _hexChars[(int)(id >> 0) & 0x0f]; + // The following routine is ~310% faster than calling long.ToString() on x64 + // and ~600% faster than calling long.ToString() on x86 in tight loops of 1 million+ iterations + // See: https://github.com/aspnet/Hosting/pull/385 - return new string(charBuffer); + // stackalloc to allocate array on stack rather than heap + char* charBuffer = stackalloc char[13]; + + charBuffer[0] = _encode32Chars[(int)(id >> 60) & 31]; + charBuffer[1] = _encode32Chars[(int)(id >> 55) & 31]; + charBuffer[2] = _encode32Chars[(int)(id >> 50) & 31]; + charBuffer[3] = _encode32Chars[(int)(id >> 45) & 31]; + charBuffer[4] = _encode32Chars[(int)(id >> 40) & 31]; + charBuffer[5] = _encode32Chars[(int)(id >> 35) & 31]; + charBuffer[6] = _encode32Chars[(int)(id >> 30) & 31]; + charBuffer[7] = _encode32Chars[(int)(id >> 25) & 31]; + charBuffer[8] = _encode32Chars[(int)(id >> 20) & 31]; + charBuffer[9] = _encode32Chars[(int)(id >> 15) & 31]; + charBuffer[10] = _encode32Chars[(int)(id >> 10) & 31]; + charBuffer[11] = _encode32Chars[(int)(id >> 5) & 31]; + charBuffer[12] = _encode32Chars[(int)id & 31]; + + // string ctor overload that takes char* + return new string(charBuffer, 0, 13); } } } diff --git a/src/Microsoft.AspNet.Hosting/project.json b/src/Microsoft.AspNet.Hosting/project.json index 10d8cfadfb..18ea116249 100644 --- a/src/Microsoft.AspNet.Hosting/project.json +++ b/src/Microsoft.AspNet.Hosting/project.json @@ -5,7 +5,10 @@ "type": "git", "url": "git://github.com/aspnet/hosting" }, - "compilationOptions": { "warningsAsErrors": true }, + "compilationOptions": { + "warningsAsErrors": true, + "allowUnsafe": true + }, "dependencies": { "Microsoft.AspNet.FileProviders.Physical": "1.0.0-*", "Microsoft.AspNet.Hosting.Abstractions": "1.0.0-*",