Perf - enumerate with struct

Conflicts:
	src/Microsoft.AspNet.Server.Kestrel/project.json

src/Microsoft.AspNet.Server.Kestrel.GeneratedCode/KnownHeaders.cs

@@ -10,9 +10,9 @@ namespace Microsoft.AspNet.Server.Kestrel.GeneratedCode
     // To enable this option, right-click on the project and select the Properties menu item. In the Build tab select "Produce outputs on build".
     public class KnownHeaders : ICompileModule
     {
-        string Each<T>(IEnumerable<T> values, Func<T, string> formatter)
+        static string Each<T>(IEnumerable<T> values, Func<T, string> formatter)
         {
-            return values.Select(formatter).Aggregate((a, b) => a + b + "\r\n");
+            return values.Select(formatter).Aggregate((a, b) => a + b);
         }
 
         class KnownHeader
@@ -26,6 +26,12 @@ namespace Microsoft.AspNet.Server.Kestrel.GeneratedCode
         }
 
         public virtual void BeforeCompile(BeforeCompileContext context)
+        {
+            var syntaxTree = Microsoft.CodeAnalysis.CSharp.CSharpSyntaxTree.ParseText(GeneratedFile());
+            context.Compilation = context.Compilation.AddSyntaxTrees(syntaxTree);
+        }
+
+        public static string GeneratedFile()
         {
             var commonHeaders = new[]
             {
@@ -71,7 +77,7 @@ namespace Microsoft.AspNet.Server.Kestrel.GeneratedCode
                 "Referer",
                 "Range",
                 "TE",
-                "Translage",
+                "Translate",
                 "User-Agent",
             }).Select((header, index) => new KnownHeader
             {
@@ -113,7 +119,7 @@ namespace Microsoft.AspNet.Server.Kestrel.GeneratedCode
                 }
             };
 
-            var syntaxTree = Microsoft.CodeAnalysis.CSharp.CSharpSyntaxTree.ParseText($@"
+            return $@"
 using System;
 using System.Collections.Generic;
 
@@ -122,11 +128,12 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
     public partial class {loop.ClassName} 
     {{
         long _bits = 0;
-        {Each(loop.Headers, header => "string[] _" + header.Identifier + ";")}
+        {Each(loop.Headers, header => @"
+        string[] _" + header.Identifier + ";")}
 
         protected override int GetCountFast()
         {{
-            var count = Unknown.Count;
+            var count = MaybeUnknown?.Count ?? 0;
             {Each(loop.Headers, header => $@"
                 if ({header.TestBit()}) 
                 {{
@@ -142,7 +149,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             {{{Each(loop.HeadersByLength, byLength => $@"
                 case {byLength.Key}:
                     {{{Each(byLength, header => $@"
-                        if (0 == StringComparer.OrdinalIgnoreCase.Compare(key, ""{header.Name}"")) 
+                        if (""{header.Name}"".Equals(key, StringComparison.OrdinalIgnoreCase)) 
                         {{
                             if ({header.TestBit()})
                             {{
@@ -156,7 +163,11 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
                     ")}}}
                     break;
             ")}}}
-            return Unknown[key];
+            if (MaybeUnknown == null) 
+            {{
+                throw new System.Collections.Generic.KeyNotFoundException();
+            }}
+            return MaybeUnknown[key];
         }}
 
         protected override bool TryGetValueFast(string key, out string[] value)
@@ -165,7 +176,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             {{{Each(loop.HeadersByLength, byLength => $@"
                 case {byLength.Key}:
                     {{{Each(byLength, header => $@"
-                        if (0 == StringComparer.OrdinalIgnoreCase.Compare(key, ""{header.Name}"")) 
+                        if (""{header.Name}"".Equals(key, StringComparison.OrdinalIgnoreCase)) 
                         {{
                             if ({header.TestBit()})
                             {{
@@ -181,7 +192,8 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
                     ")}}}
                     break;
             ")}}}
-            return Unknown.TryGetValue(key, out value);
+            value = null;
+            return MaybeUnknown?.TryGetValue(key, out value) ?? false;
         }}
 
         protected override void SetValueFast(string key, string[] value)
@@ -190,7 +202,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             {{{Each(loop.HeadersByLength, byLength => $@"
                 case {byLength.Key}:
                     {{{Each(byLength, header => $@"
-                        if (0 == StringComparer.OrdinalIgnoreCase.Compare(key, ""{header.Name}"")) 
+                        if (""{header.Name}"".Equals(key, StringComparison.OrdinalIgnoreCase)) 
                         {{
                             {header.SetBit()};
                             _{header.Identifier} = value;
@@ -208,7 +220,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             {{{Each(loop.HeadersByLength, byLength => $@"
                 case {byLength.Key}:
                     {{{Each(byLength, header => $@"
-                        if (0 == StringComparer.OrdinalIgnoreCase.Compare(key, ""{header.Name}"")) 
+                        if (""{header.Name}"".Equals(key, StringComparison.OrdinalIgnoreCase)) 
                         {{
                             if ({header.TestBit()})
                             {{
@@ -230,7 +242,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             {{{Each(loop.HeadersByLength, byLength => $@"
                 case {byLength.Key}:
                     {{{Each(byLength, header => $@"
-                        if (0 == StringComparer.OrdinalIgnoreCase.Compare(key, ""{header.Name}"")) 
+                        if (""{header.Name}"".Equals(key, StringComparison.OrdinalIgnoreCase)) 
                         {{
                             if ({header.TestBit()})
                             {{
@@ -245,13 +257,13 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
                     ")}}}
                     break;
             ")}}}
-            return Unknown.Remove(key);
+            return MaybeUnknown?.Remove(key) ?? false;
         }}
 
         protected override void ClearFast()
         {{
             _bits = 0;
-            Unknown.Clear();
+            MaybeUnknown?.Clear();
         }}
         
         protected override void CopyToFast(KeyValuePair<string, string[]>[] array, int arrayIndex)
@@ -273,27 +285,44 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
                     ++arrayIndex;
                 }}
             ")}
-            ((ICollection<KeyValuePair<string, string[]>>)Unknown).CopyTo(array, arrayIndex);
+            ((ICollection<KeyValuePair<string, string[]>>)MaybeUnknown)?.CopyTo(array, arrayIndex);
         }}
 
-        protected override IEnumerable<KeyValuePair<string, string[]>> EnumerateFast()
+        public partial struct Enumerator
         {{
-            {Each(loop.Headers, header => $@"
+            public bool MoveNext()
-                if ({header.TestBit()}) 
-                {{
-                    yield return new KeyValuePair<string, string[]>(""{header.Name}"", _{header.Identifier});
-                }}
-            ")}
-            foreach(var kv in Unknown)
             {{
-                yield return kv;
+                switch (_state)
+                {{
+                    {Each(loop.Headers, header => $@"
+                        case {header.Index}:
+                            goto state{header.Index};
+                    ")}
+                    default:
+                        goto state_default;
+                }}
+                {Each(loop.Headers, header => $@"
+                state{header.Index}:
+                    if ({header.TestBit()})
+                    {{
+                        _current = new KeyValuePair<string, string[]>(""{header.Name}"", _collection._{header.Identifier});
+                        _state = {header.Index + 1};
+                        return true;
+                    }}
+                ")}
+                state_default:
+                    if (!_hasUnknown || !_unknownEnumerator.MoveNext())
+                    {{
+                        _current = default(KeyValuePair<string, string[]>);
+                        return false;
+                    }}
+                    _current = _unknownEnumerator.Current;
+                    return true;
             }}
         }}
     }}
 ")}}}
-");
+";
-
-            context.Compilation = context.Compilation.AddSyntaxTrees(syntaxTree);
         }
 
         public virtual void AfterCompile(AfterCompileContext context)

src/Microsoft.AspNet.Server.Kestrel.GeneratedCode/Program.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNet.Server.Kestrel.GeneratedCode
+{
+    public class Program
+    {
+        public int Main(string[] args)
+        {
+            var text = KnownHeaders.GeneratedFile();
+
+            if (args.Length == 1)
+            {
+                var existing = File.Exists(args[0]) ? File.ReadAllText(args[0]) : "";
+                if (!string.Equals(text, existing))
+                {
+                    File.WriteAllText(args[0], text);
+                }
+            }
+            else
+            {
+                Console.WriteLine(text);
+            }
+            return 0;
+        }
+    }
+}

src/Microsoft.AspNet.Server.Kestrel/Http/Frame.cs

@@ -27,6 +27,8 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
         private bool _resultStarted;
         private bool _responseStarted;
         private bool _keepAlive;
+        private readonly FrameRequestHeaders _requestHeaders = new FrameRequestHeaders();
+        private readonly FrameResponseHeaders _responseHeaders = new FrameResponseHeaders();
 
         /*
         //IDictionary<string, object> _environment;
@@ -43,8 +45,8 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
         {
             FrameControl = this;
             StatusCode = 200;
-            RequestHeaders = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase);
+            RequestHeaders = _requestHeaders;
-            ResponseHeaders = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase);
+            ResponseHeaders = _responseHeaders;
         }
 
         public string Method { get; set; }

src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.cs

@@ -5,17 +5,11 @@ using System.Linq;
 
 namespace Microsoft.AspNet.Server.Kestrel.Http
 {
-    public partial class FrameRequestHeaders : FrameHeaders
-    {
-    }
-
-    public partial class FrameResponseHeaders : FrameHeaders
-    {
-    }
-
     public abstract class FrameHeaders : IDictionary<string, string[]>
     {
-        protected Dictionary<string, string[]> Unknown = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase);
+        protected Dictionary<string, string[]> MaybeUnknown;
+
+        protected Dictionary<string, string[]> Unknown => MaybeUnknown ?? (MaybeUnknown = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase));
 
         protected virtual int GetCountFast()
         { throw new NotImplementedException(); }
@@ -41,7 +35,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
         protected virtual void CopyToFast(KeyValuePair<string, string[]>[] array, int arrayIndex)
         { throw new NotImplementedException(); }
 
-        protected virtual IEnumerable<KeyValuePair<string, string[]>> EnumerateFast()
+        protected virtual IEnumerator<KeyValuePair<string, string[]>> GetEnumeratorFast()
         { throw new NotImplementedException(); }
 
 
@@ -62,9 +56,9 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
 
         bool ICollection<KeyValuePair<string, string[]>>.IsReadOnly => false;
 
-        ICollection<string> IDictionary<string, string[]>.Keys => EnumerateFast().Select(x => x.Key).ToList();
+        ICollection<string> IDictionary<string, string[]>.Keys => ((IDictionary<string,string[]>)this).Select(x => x.Key).ToList();
 
-        ICollection<string[]> IDictionary<string, string[]>.Values => EnumerateFast().Select(x => x.Value).ToList();
+        ICollection<string[]> IDictionary<string, string[]>.Values => ((IDictionary<string, string[]>)this).Select(x => x.Value).ToList();
 
         void ICollection<KeyValuePair<string, string[]>>.Add(KeyValuePair<string, string[]> item)
         {
@@ -102,12 +96,12 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
 
         IEnumerator IEnumerable.GetEnumerator()
         {
-            return EnumerateFast().GetEnumerator();
+            return GetEnumeratorFast();
         }
 
         IEnumerator<KeyValuePair<string, string[]>> IEnumerable<KeyValuePair<string, string[]>>.GetEnumerator()
         {
-            return EnumerateFast().GetEnumerator();
+            return GetEnumeratorFast();
         }
 
         bool ICollection<KeyValuePair<string, string[]>>.Remove(KeyValuePair<string, string[]> item)
@@ -129,4 +123,100 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             return TryGetValueFast(key, out value);
         }
     }
+
+    public partial class FrameRequestHeaders : FrameHeaders
+    {
+        public Enumerator GetEnumerator()
+        {
+            return new Enumerator(this);
+        }
+
+        protected override IEnumerator<KeyValuePair<string, string[]>> GetEnumeratorFast()
+        {
+            return GetEnumerator();
+        }
+
+        public partial struct Enumerator : IEnumerator<KeyValuePair<string, string[]>>
+        {
+            FrameRequestHeaders _collection;
+            long _bits;
+            int _state;
+            KeyValuePair<string, string[]> _current;
+            bool _hasUnknown;
+            Dictionary<string, string[]>.Enumerator _unknownEnumerator;
+
+            internal Enumerator(FrameRequestHeaders collection)
+            {
+                _collection = collection;
+                _bits = collection._bits;
+                _state = 0;
+                _current = default(KeyValuePair<string, string[]>);
+                _hasUnknown = collection.MaybeUnknown != null;
+                _unknownEnumerator = _hasUnknown
+                    ? collection.MaybeUnknown.GetEnumerator()
+                    : default(Dictionary<string, string[]>.Enumerator);
+            }
+
+            public KeyValuePair<string, string[]> Current => _current;
+
+            object IEnumerator.Current => _current;
+
+            public void Dispose()
+            {
+            }
+
+            public void Reset()
+            {
+                _state = 0;
+            }
+        }
+    }
+
+    public partial class FrameResponseHeaders : FrameHeaders
+    {
+        public Enumerator GetEnumerator()
+        {
+            return new Enumerator(this);
+        }
+
+        protected override IEnumerator<KeyValuePair<string, string[]>> GetEnumeratorFast()
+        {
+            return GetEnumerator();
+        }
+
+        public partial struct Enumerator : IEnumerator<KeyValuePair<string, string[]>>
+        {
+            FrameResponseHeaders _collection;
+            long _bits;
+            int _state;
+            KeyValuePair<string, string[]> _current;
+            bool _hasUnknown;
+            Dictionary<string, string[]>.Enumerator _unknownEnumerator;
+
+            internal Enumerator(FrameResponseHeaders collection)
+            {
+                _collection = collection;
+                _bits = collection._bits;
+                _state = 0;
+                _current = default(KeyValuePair<string, string[]>);
+                _hasUnknown = collection.MaybeUnknown != null;
+                _unknownEnumerator = _hasUnknown
+                    ? collection.MaybeUnknown.GetEnumerator()
+                    : default(Dictionary<string, string[]>.Enumerator);
+            }
+
+            public KeyValuePair<string, string[]> Current => _current;
+
+            object IEnumerator.Current => _current;
+
+            public void Dispose()
+            {
+            }
+
+            public void Reset()
+            {
+                _state = 0;
+            }
+        }
+    }
 }

src/Microsoft.AspNet.Server.Kestrel/compiler/preprocess/KnownHeaders.cs

@@ -1,11 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-
-namespace Microsoft.AspNet.Server.Kestrel
-{
-    public class KnownHeaders : Microsoft.AspNet.Server.Kestrel.GeneratedCode.KnownHeaders
-    {
-    }
-}

src/Microsoft.AspNet.Server.Kestrel/project.json

@@ -6,8 +6,7 @@
         "url": "git://github.com/aspnet/kestrelhttpserver"
     },
     "dependencies": {
-        "Microsoft.Dnx.Runtime.Abstractions": "1.0.0-beta7-*",
+        "Microsoft.Dnx.Runtime.Abstractions": "1.0.0-beta7-*"
-        "Microsoft.AspNet.Server.Kestrel.GeneratedCode": { "version": "1.0.0-*", "type": "build" }
     },
     "frameworks": {
         "dnx451": { },
@@ -33,5 +32,8 @@
     },
     "compilationOptions": {
         "allowUnsafe": true
+    },
+    "scripts": {
+        "prepare": "dnx ../Microsoft.AspNet.Server.Kestrel.GeneratedCode run Http/FrameHeaders.Generated.cs"
     }
 }