Reduce allocations for Cookies. (#31258)

Author: jkotalik

src/Http/Headers/src/CookieHeaderParser.cs

@@ -1,7 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System.Diagnostics.Contracts;
 using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.Net.Http.Headers
@@ -13,83 +12,24 @@ internal CookieHeaderParser(bool supportsMultipleValues)
         {
         }
 
-        public override bool TryParseValue(StringSegment value, ref int index, out CookieHeaderValue? parsedValue)
+        public override bool TryParseValue(StringSegment value, ref int index, out CookieHeaderValue? cookieValue)
         {
-            parsedValue = null;
+            cookieValue = null;
 
-            // If multiple values are supported (i.e. list of values), then accept an empty string: The header may
-            // be added multiple times to the request/response message. E.g.
-            //  Accept: text/xml; q=1
-            //  Accept:
-            //  Accept: text/plain; q=0.2
-            if (StringSegment.IsNullOrEmpty(value) || (index == value.Length))
-            {
-                return SupportsMultipleValues;
-            }
-
-            var current = GetNextNonEmptyOrWhitespaceIndex(value, index, SupportsMultipleValues, out bool separatorFound);
-
-            if (separatorFound && !SupportsMultipleValues)
-            {
-                return false; // leading separators not allowed if we don't support multiple values.
-            }
-
-            if (current == value.Length)
-            {
-                if (SupportsMultipleValues)
-                {
-                    index = current;
-                }
-                return SupportsMultipleValues;
-            }
-
-            if (!CookieHeaderValue.TryGetCookieLength(value, ref current, out var result))
+            if (!CookieHeaderParserShared.TryParseValue(value, ref index, SupportsMultipleValues, out var parsedName, out var parsedValue))
             {
                 return false;
             }
 
-            current = GetNextNonEmptyOrWhitespaceIndex(value, current, SupportsMultipleValues, out separatorFound);
-
-            // If we support multiple values and we've not reached the end of the string, then we must have a separator.
-            if ((separatorFound && !SupportsMultipleValues) || (!separatorFound && (current < value.Length)))
+            if (parsedName == null || parsedValue == null)
             {
-                return false;
+                // Successfully parsed, but no values.
+                return true;
             }
 
-            index = current;
-            parsedValue = result;
-            return true;
-        }
-
-        private static int GetNextNonEmptyOrWhitespaceIndex(StringSegment input, int startIndex, bool skipEmptyValues, out bool separatorFound)
-        {
-            Contract.Requires(startIndex <= input.Length); // it's OK if index == value.Length.
-
-            separatorFound = false;
-            var current = startIndex + HttpRuleParser.GetWhitespaceLength(input, startIndex);
-
-            if ((current == input.Length) || (input[current] != ',' && input[current] != ';'))
-            {
-                return current;
-            }
-
-            // If we have a separator, skip the separator and all following whitespaces. If we support
-            // empty values, continue until the current character is neither a separator nor a whitespace.
-            separatorFound = true;
-            current++; // skip delimiter.
-            current = current + HttpRuleParser.GetWhitespaceLength(input, current);
-
-            if (skipEmptyValues)
-            {
-                // Most headers only split on ',', but cookies primarily split on ';'
-                while ((current < input.Length) && ((input[current] == ',') || (input[current] == ';')))
-                {
-                    current++; // skip delimiter.
-                    current = current + HttpRuleParser.GetWhitespaceLength(input, current);
-                }
-            }
+            cookieValue = new CookieHeaderValue(parsedName.Value, parsedValue.Value);
 
-            return current;
+            return true;
         }
     }
 }

src/Http/Headers/src/CookieHeaderValue.cs

@@ -165,121 +165,6 @@ public static bool TryParseStrictList(IList<string>? inputs, [NotNullWhen(true)]
             return MultipleValueParser.TryParseStrictValues(inputs, out parsedValues);
         }
 
-        // name=value; name="value"
-        internal static bool TryGetCookieLength(StringSegment input, ref int offset, [NotNullWhen(true)] out CookieHeaderValue? parsedValue)
-        {
-            Contract.Requires(offset >= 0);
-
-            parsedValue = null;
-
-            if (StringSegment.IsNullOrEmpty(input) || (offset >= input.Length))
-            {
-                return false;
-            }
-
-            var result = new CookieHeaderValue();
-
-            // The caller should have already consumed any leading whitespace, commas, etc..
-
-            // Name=value;
-
-            // Name
-            var itemLength = HttpRuleParser.GetTokenLength(input, offset);
-            if (itemLength == 0)
-            {
-                return false;
-            }
-            result._name = input.Subsegment(offset, itemLength);
-            offset += itemLength;
-
-            // = (no spaces)
-            if (!ReadEqualsSign(input, ref offset))
-            {
-                return false;
-            }
-
-            // value or "quoted value"
-            // The value may be empty
-            result._value = GetCookieValue(input, ref offset);
-
-            parsedValue = result;
-            return true;
-        }
-
-        // cookie-value      = *cookie-octet / ( DQUOTE* cookie-octet DQUOTE )
-        // cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
-        //                     ; US-ASCII characters excluding CTLs, whitespace DQUOTE, comma, semicolon, and backslash
-        internal static StringSegment GetCookieValue(StringSegment input, ref int offset)
-        {
-            Contract.Requires(offset >= 0);
-            Contract.Ensures((Contract.Result<int>() >= 0) && (Contract.Result<int>() <= (input.Length - offset)));
-
-            var startIndex = offset;
-
-            if (offset >= input.Length)
-            {
-                return StringSegment.Empty;
-            }
-            var inQuotes = false;
-
-            if (input[offset] == '"')
-            {
-                inQuotes = true;
-                offset++;
-            }
-
-            while (offset < input.Length)
-            {
-                var c = input[offset];
-                if (!IsCookieValueChar(c))
-                {
-                    break;
-                }
-
-                offset++;
-            }
-
-            if (inQuotes)
-            {
-                if (offset == input.Length || input[offset] != '"')
-                {
-                    // Missing final quote
-                    return StringSegment.Empty;
-                }
-                offset++;
-            }
-
-            int length = offset - startIndex;
-            if (offset > startIndex)
-            {
-                return input.Subsegment(startIndex, length);
-            }
-
-            return StringSegment.Empty;
-        }
-
-        private static bool ReadEqualsSign(StringSegment input, ref int offset)
-        {
-            // = (no spaces)
-            if (offset >= input.Length || input[offset] != '=')
-            {
-                return false;
-            }
-            offset++;
-            return true;
-        }
-
-        // cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
-        //                     ; US-ASCII characters excluding CTLs, whitespace DQUOTE, comma, semicolon, and backslash
-        private static bool IsCookieValueChar(char c)
-        {
-            if (c < 0x21 || c > 0x7E)
-            {
-                return false;
-            }
-            return !(c == '"' || c == ',' || c == ';' || c == '\\');
-        }
-
         internal static void CheckNameFormat(StringSegment name, string parameterName)
         {
             if (name == null)
@@ -301,7 +186,7 @@ internal static void CheckValueFormat(StringSegment value, string parameterName)
             }
 
             var offset = 0;
-            var result = GetCookieValue(value, ref offset);
+            var result = CookieHeaderParserShared.GetCookieValue(value, ref offset);
             if (result.Length != value.Length)
             {
                 throw new ArgumentException("Invalid cookie value: " + value, parameterName);

src/Http/Headers/src/Microsoft.Net.Http.Headers.csproj

@@ -13,6 +13,9 @@
 
   <ItemGroup>
     <Reference Include="Microsoft.Extensions.Primitives" />
+    <Compile Include="..\..\Shared\CookieHeaderParserShared.cs" Link="CookieHeaderParserShared.cs" />
+    <Compile Include="..\..\Shared\HttpRuleParser.cs" />
+    <Compile Include="..\..\Shared\HttpParseResult.cs" />
   </ItemGroup>
 
 </Project>

src/Http/Headers/src/SetCookieHeaderValue.cs

@@ -494,7 +494,7 @@ private static int GetSetCookieLength(StringSegment input, int startIndex, out S
 
             // value or "quoted value"
             // The value may be empty
-            result._value = CookieHeaderValue.GetCookieValue(input, ref offset);
+            result._value = CookieHeaderParserShared.GetCookieValue(input, ref offset);
 
             // *(';' SP cookie-av)
             while (offset < input.Length)

src/Http/Http/perf/Microbenchmarks/RequestCookieCollectionBenchmarks.cs

@@ -0,0 +1,25 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using BenchmarkDotNet.Attributes;
+using Microsoft.Extensions.Primitives;
+
+namespace Microsoft.AspNetCore.Http
+{
+    public class RequestCookieCollectionBenchmarks
+    {
+        private StringValues _cookie;
+
+        [IterationSetup]
+        public void Setup()
+        {
+            _cookie = ".AspNetCore.Cookies=CfDJ8BAklVa9EYREk8_ipRUUYJYhRsleKr485k18s_q5XD6vcRJ-DtowUuLCwwMiY728zRZ3rVFY3DEcXDAQUOTtg1e4tkSIVmYLX38Q6mqdFFyw-8dksclDywe9vnN84cEWvfV0wP3EgOsJGHaND7kTJ47gr7Pc1tLHWOm4Pe7Q1vrT9EkcTMr1Wts3aptBl3bdOLLqjmSdgk-OI7qG7uQGz1OGdnSer6-KLUPBcfXblzs4YCjvwu3bGnM42xLGtkZNIF8izPpyqKkIf7ec6O6LEHMp4gcq86PGHCXHn5NKuNSD";
+        }
+
+        [Benchmark]
+        public void Parse_TypicalCookie()
+        {
+            RequestCookieCollection.Parse(_cookie);
+        }
+    }
+}

src/Http/Http/perf/Microbenchmarks/RouteValueDictionaryBenchmark.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;

src/Http/Http/src/Features/RequestCookiesFeature.cs

@@ -75,7 +75,7 @@ public IRequestCookieCollection Cookies
                 if (_parsedValues == null || _original != current)
                 {
                     _original = current;
-                    _parsedValues = RequestCookieCollection.Parse(current.ToArray());
+                    _parsedValues = RequestCookieCollection.Parse(current);
                 }
 
                 return _parsedValues;

src/Http/Http/src/Internal/RequestCookieCollection.cs

@@ -5,6 +5,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using Microsoft.Extensions.Primitives;
 using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Http
@@ -56,33 +57,25 @@ public string? this[string key]
             }
         }
 
-        public static RequestCookieCollection Parse(IList<string> values)
-            => ParseInternal(values, AppContext.TryGetSwitch(ResponseCookies.EnableCookieNameEncoding, out var enabled) && enabled);
+        public static RequestCookieCollection Parse(StringValues values)
+           => ParseInternal(values, AppContext.TryGetSwitch(ResponseCookies.EnableCookieNameEncoding, out var enabled) && enabled);
 
-        internal static RequestCookieCollection ParseInternal(IList<string> values, bool enableCookieNameEncoding)
+        internal static RequestCookieCollection ParseInternal(StringValues values, bool enableCookieNameEncoding)
         {
             if (values.Count == 0)
             {
                 return Empty;
             }
+            var collection = new RequestCookieCollection(values.Count);
+            var store = collection.Store!;
 
-            if (CookieHeaderValue.TryParseList(values, out var cookies))
+            if (CookieHeaderParserShared.TryParseValues(values, store, enableCookieNameEncoding, supportsMultipleValues: true))
             {
-                if (cookies.Count == 0)
+                if (store.Count == 0)
                 {
                     return Empty;
                 }
 
-                var collection = new RequestCookieCollection(cookies.Count);
-                var store = collection.Store!;
-                for (var i = 0; i < cookies.Count; i++)
-                {
-                    var cookie = cookies[i];
-                    var name = enableCookieNameEncoding ? Uri.UnescapeDataString(cookie.Name.Value) : cookie.Name.Value;
-                    var value = Uri.UnescapeDataString(cookie.Value.Value);
-                    store[name] = value;
-                }
-
                 return collection;
             }
             return Empty;

src/Http/Http/src/Microsoft.AspNetCore.Http.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Description>ASP.NET Core default HTTP feature implementations.</Description>
@@ -15,6 +15,9 @@
     <Compile Include="$(SharedSourceRoot)CopyOnWriteDictionary\*.cs" />
     <Compile Include="$(SharedSourceRoot)ValueTaskExtensions\**\*.cs" />
     <Compile Include="..\..\Shared\StreamCopyOperationInternal.cs" Link="Internal\StreamCopyOperationInternal.cs" />
+    <Compile Include="..\..\Shared\CookieHeaderParserShared.cs" Link="Internal\CookieHeaderParserShared.cs" />
+    <Compile Include="..\..\Shared\HttpRuleParser.cs" LinkBase="Internal" />
+    <Compile Include="..\..\Shared\HttpParseResult.cs" LinkBase="Internal" />
     <Compile Include="..\..\WebUtilities\src\AspNetCoreTempDirectory.cs" LinkBase="Internal" />
   </ItemGroup>
 

src/Http/Http/src/Properties/AssemblyInfo.cs

@@ -1,3 +1,4 @@
 using System.Runtime.CompilerServices;
 
 [assembly: InternalsVisibleTo("Microsoft.AspNetCore.Http.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]
+[assembly: InternalsVisibleTo("Microsoft.AspNetCore.Http.MicroBenchmarks, PublicKey=0024000004800000940000000602000000240000525341310004000001000100f33a29044fa9d740c9b3213a93e57c84b472c84e0b8a0e1ae48e67a9f8f6de9d5f7f3d52ac23e48ac51801f1dc950abe901da34d2a9e3baadb141a17c77ef3c565dd5ee5054b91cf63bb3c6ab83f72ab3aafe93d0fc3c2348b764fafb0b1c0733de51459aeab46580384bf9d74c4e28164b7cde247f891ba07891c9d872ad2bb")]