Remove InplaceStringBuilder usages (#6163)

src/Http/Headers/src/HeaderUtilities.cs

@@ -625,7 +625,7 @@ namespace Microsoft.Net.Http.Headers
         {
             input = RemoveQuotes(input);
 
-            // First pass to calculate the size of the InplaceStringBuilder
+            // First pass to calculate the size of the string
             var backSlashCount = CountBackslashesForDecodingQuotedString(input);
 
             if (backSlashCount == 0)
@@ -633,26 +633,32 @@ namespace Microsoft.Net.Http.Headers
                 return input;
             }
 
-            var stringBuilder = new InplaceStringBuilder(input.Length - backSlashCount);
+            return string.Create(input.Length - backSlashCount, input, (span, segment) =>
-
-            for (var i = 0; i < input.Length; i++)
             {
-                if (i < input.Length - 1 && input[i] == '\\')
+                var spanIndex = 0;
+                var spanLength = span.Length;
+                for (var i = 0; i < segment.Length && (uint)spanIndex < (uint)spanLength; i++)
                 {
-                    // If there is an backslash character as the last character in the string,
+                    int nextIndex = i + 1;
-                    // we will assume that it should be included literally in the unescaped string
+                    if ((uint)nextIndex < (uint)segment.Length && segment[i] == '\\')
-                    // Ex: "hello\\" => "hello\\"
+                    {
-                    // Also, if a sender adds a quoted pair like '\\''n',
+                        // If there is an backslash character as the last character in the string,
-                    // we will assume it is over escaping and just add a n to the string.
+                        // we will assume that it should be included literally in the unescaped string
-                    // Ex: "he\\llo" => "hello"
+                        // Ex: "hello\\" => "hello\\"
-                    stringBuilder.Append(input[i + 1]);
+                        // Also, if a sender adds a quoted pair like '\\''n',
-                    i++;
+                        // we will assume it is over escaping and just add a n to the string.
-                    continue;
+                        // Ex: "he\\llo" => "hello"
-                }
+                        span[spanIndex] = segment[nextIndex];
-                stringBuilder.Append(input[i]);
+                        i++;
-            }
+                    }
+                    else
+                    {
+                        span[spanIndex] = segment[i];
+                    }
 
-            return stringBuilder.ToString();
+                    spanIndex++;
+                }
+            });
         }
 
         private static int CountBackslashesForDecodingQuotedString(StringSegment input)
@@ -696,25 +702,27 @@ namespace Microsoft.Net.Http.Headers
             // By calling this, we know that the string requires quotes around it to be a valid token.
             var backSlashCount = CountAndCheckCharactersNeedingBackslashesWhenEncoding(input);
 
-            var stringBuilder = new InplaceStringBuilder(input.Length + backSlashCount + 2); // 2 for quotes
+            // 2 for quotes
-            stringBuilder.Append('\"');
+            return string.Create(input.Length + backSlashCount + 2, input, (span, segment) => {
+                // Helps to elide the bounds check for span[0]
+                span[span.Length - 1] = span[0] = '\"';
 
-            for (var i = 0; i < input.Length; i++)
+                var spanIndex = 1;
-            {
+                for (var i = 0; i < segment.Length; i++)
-                if (input[i] == '\\' || input[i] == '\"')
                 {
-                    stringBuilder.Append('\\');
+                    if (segment[i] == '\\' || segment[i] == '\"')
+                    {
+                        span[spanIndex++] = '\\';
+                    }
+                    else if ((segment[i] <= 0x1F || segment[i] == 0x7F) && segment[i] != 0x09)
+                    {
+                        // Control characters are not allowed in a quoted-string, which include all characters
+                        // below 0x1F (except for 0x09 (TAB)) and 0x7F.
+                        throw new FormatException($"Invalid control character '{segment[i]}' in input.");
+                    }
+                    span[spanIndex++] = segment[i];
                 }
-                else if ((input[i] <= 0x1F || input[i] == 0x7F) && input[i] != 0x09)
+            });
-                {
-                    // Control characters are not allowed in a quoted-string, which include all characters
-                    // below 0x1F (except for 0x09 (TAB)) and 0x7F.
-                    throw new FormatException($"Invalid control character '{input[i]}' in input.");
-                }
-                stringBuilder.Append(input[i]);
-            }
-            stringBuilder.Append('\"');
-            return stringBuilder.ToString();
         }
 
         private static int CountAndCheckCharactersNeedingBackslashesWhenEncoding(StringSegment input)

src/Http/Headers/src/SetCookieHeaderValue.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Diagnostics.Contracts;
 using System.Text;
 using Microsoft.Extensions.Primitives;
@@ -24,7 +25,8 @@ namespace Microsoft.Net.Http.Headers
         private const string HttpOnlyToken = "httponly";
         private const string SeparatorToken = "; ";
         private const string EqualsToken = "=";
-        private const string DefaultPath = "/"; // TODO: Used?
+        private const int ExpiresDateLength = 29;
+        private const string ExpiresDateFormat = "r";
 
         private static readonly HttpHeaderParser<SetCookieHeaderValue> SingleValueParser
             = new GenericHeaderParser<SetCookieHeaderValue>(false, GetSetCookieLength);
@@ -99,14 +101,11 @@ namespace Microsoft.Net.Http.Headers
         {
             var length = _name.Length + EqualsToken.Length + _value.Length;
 
-            string expires = null;
             string maxAge = null;
-            string sameSite = null;
 
             if (Expires.HasValue)
             {
-                expires = HeaderUtilities.FormatDate(Expires.GetValueOrDefault());
+                length += SeparatorToken.Length + ExpiresToken.Length + EqualsToken.Length + ExpiresDateLength;
-                length += SeparatorToken.Length + ExpiresToken.Length + EqualsToken.Length + expires.Length;
             }
 
             if (MaxAge.HasValue)
@@ -132,7 +131,7 @@ namespace Microsoft.Net.Http.Headers
 
             if (SameSite != SameSiteMode.None)
             {
-                sameSite = SameSite == SameSiteMode.Lax ? SameSiteLaxToken : SameSiteStrictToken;
+                var sameSite = SameSite == SameSiteMode.Lax ? SameSiteLaxToken : SameSiteStrictToken;
                 length += SeparatorToken.Length + SameSiteToken.Length + EqualsToken.Length + sameSite.Length;
             }
 
@@ -141,61 +140,75 @@ namespace Microsoft.Net.Http.Headers
                 length += SeparatorToken.Length + HttpOnlyToken.Length;
             }
 
-            var sb = new InplaceStringBuilder(length);
+            return string.Create(length, (this, maxAge), (span, tuple) =>
-
-            sb.Append(_name);
-            sb.Append(EqualsToken);
-            sb.Append(_value);
-
-            if (expires != null)
             {
-                AppendSegment(ref sb, ExpiresToken, expires);
+                var (headerValue, maxAgeValue) = tuple;
-            }
 
-            if (maxAge != null)
+                Append(ref span, headerValue._name);
-            {
+                Append(ref span, EqualsToken);
-                AppendSegment(ref sb, MaxAgeToken, maxAge);
+                Append(ref span, headerValue._value);
-            }
 
-            if (Domain != null)
+                if (headerValue.Expires is DateTimeOffset expiresValue)
-            {
+                {
-                AppendSegment(ref sb, DomainToken, Domain);
+                    Append(ref span, SeparatorToken);
-            }
+                    Append(ref span, ExpiresToken);
+                    Append(ref span, EqualsToken);
 
-            if (Path != null)
+                    var formatted = expiresValue.TryFormat(span, out var charsWritten, ExpiresDateFormat);
-            {
+                    span = span.Slice(charsWritten);
-                AppendSegment(ref sb, PathToken, Path);
-            }
 
-            if (Secure)
+                    Debug.Assert(formatted);
-            {
+                }
-                AppendSegment(ref sb, SecureToken, null);
-            }
 
-            if (SameSite != SameSiteMode.None)
+                if (maxAgeValue != null)
-            {
+                {
-                AppendSegment(ref sb, SameSiteToken, sameSite);
+                    AppendSegment(ref span, MaxAgeToken, maxAgeValue);
-            }
+                }
 
-            if (HttpOnly)
+                if (headerValue.Domain != null)
-            {
+                {
-                AppendSegment(ref sb, HttpOnlyToken, null);
+                    AppendSegment(ref span, DomainToken, headerValue.Domain);
-            }
+                }
 
-            return sb.ToString();
+                if (headerValue.Path != null)
+                {
+                    AppendSegment(ref span, PathToken, headerValue.Path);
+                }
+
+                if (headerValue.Secure)
+                {
+                    AppendSegment(ref span, SecureToken, null);
+                }
+
+                if (headerValue.SameSite != SameSiteMode.None)
+                {
+                    AppendSegment(ref span, SameSiteToken, headerValue.SameSite == SameSiteMode.Lax ? SameSiteLaxToken : SameSiteStrictToken);
+                }
+
+                if (headerValue.HttpOnly)
+                {
+                    AppendSegment(ref span, HttpOnlyToken, null);
+                }
+            });
         }
 
-        private static void AppendSegment(ref InplaceStringBuilder builder, StringSegment name, StringSegment value)
+        private static void AppendSegment(ref Span<char> span, StringSegment name, StringSegment value)
         {
-            builder.Append(SeparatorToken);
+            Append(ref span, SeparatorToken);
-            builder.Append(name);
+            Append(ref span, name.AsSpan());
             if (value != null)
             {
-                builder.Append(EqualsToken);
+                Append(ref span, EqualsToken);
-                builder.Append(value);
+                Append(ref span, value.AsSpan());
             }
         }
 
+        private static void Append(ref Span<char> span, ReadOnlySpan<char> other)
+        {
+            other.CopyTo(span);
+            span = span.Slice(other.Length);
+        }
+
         /// <summary>
         /// Append string representation of this <see cref="SetCookieHeaderValue"/> to given
         /// <paramref name="builder"/>.
@@ -452,14 +465,14 @@ namespace Microsoft.Net.Http.Headers
                     result.HttpOnly = true;
                 }
                 // extension-av = <any CHAR except CTLs or ";">
-                else 
+                else
-                {   
+                {
                     // TODO: skiping it for now to avoid parsing failure? Store it in a list?
                     // = (no spaces)
                     if (!ReadEqualsSign(input, ref offset))
                     {
                         return 0;
-                    }                    
+                    }
                     ReadToSemicolonOrEnd(input, ref offset);
                 }
             }

src/Http/Http/perf/HeaderUtilitiesBenchmark.cs

@@ -0,0 +1,24 @@
+// 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;
+using BenchmarkDotNet.Attributes;
+using Microsoft.Extensions.Primitives;
+
+namespace Microsoft.Net.Http.Headers
+{
+    public class HeaderUtilitiesBenchmark
+    {
+        [Benchmark]
+        public StringSegment UnescapeAsQuotedString()
+        {
+            return HeaderUtilities.UnescapeAsQuotedString("\"hello\\\"foo\\\\bar\\\\baz\\\\\"");
+        }
+
+        [Benchmark]
+        public StringSegment EscapeAsQuotedString()
+        {
+            return HeaderUtilities.EscapeAsQuotedString("\"hello\\\"foo\\\\bar\\\\baz\\\\\"");
+        }
+    }
+}

src/Mvc/src/Microsoft.AspNetCore.Mvc.Razor/ViewPath.cs

@@ -1,8 +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 Microsoft.Extensions.Primitives;
-
 namespace Microsoft.AspNetCore.Mvc.Razor
 {
     internal static class ViewPath
@@ -23,23 +21,21 @@ namespace Microsoft.AspNetCore.Mvc.Razor
                 length++;
             }
 
-            var builder = new InplaceStringBuilder(length);
+            return string.Create(length, (path, addLeadingSlash), (span, tuple) =>
-            if (addLeadingSlash)
             {
-                builder.Append('/');
+                var (pathValue, addLeadingSlashValue) = tuple;
-            }
+                var spanIndex = 0;
 
-            for (var i = 0; i < path.Length; i++)
+                if (addLeadingSlashValue)
-            {
-                var ch = path[i];
-                if (ch == '\\')
                 {
-                    ch = '/';
+                    span[spanIndex++] = '/';
                 }
-                builder.Append(ch);
-            }
 
-            return builder.ToString();
+                foreach (var ch in pathValue)
+                {
+                    span[spanIndex++] = ch == '\\' ? '/' : ch;
+                }
+            });
         }
     }
 }

src/Mvc/src/Microsoft.AspNetCore.Mvc.RazorPages/ApplicationModels/PageRouteModelFactory.cs

@@ -144,12 +144,18 @@ namespace Microsoft.AspNetCore.Mvc.ApplicationModels
             Debug.Assert(!string.IsNullOrEmpty(viewEnginePath));
             Debug.Assert(viewEnginePath.StartsWith("/", StringComparison.Ordinal));
 
-            var builder = new InplaceStringBuilder(1 + areaName.Length + viewEnginePath.Length);
+            return string.Create(1 + areaName.Length + viewEnginePath.Length, (areaName, viewEnginePath), (span, tuple) =>
-            builder.Append('/');
+            {
-            builder.Append(areaName);
+                var (areaNameValue, viewEnginePathValue) = tuple;
-            builder.Append(viewEnginePath);
 
-            return builder.ToString();
+                span[0] = '/';
+                span = span.Slice(1);
+
+                areaNameValue.AsSpan().CopyTo(span);
+                span = span.Slice(areaNameValue.Length);
+
+                viewEnginePathValue.AsSpan().CopyTo(span);
+            });
         }
 
         private static SelectorModel CreateSelectorModel(string prefix, string routeTemplate)