Fast React ID Generator (#528)

* Fast ReactID Generator

* review fixes

* fix comment

Author: DaniilSokolyuk

src/React.Core/AssemblyRegistration.cs

@@ -1,4 +1,4 @@
-/*
+/*
  *  Copyright (c) 2014-Present, Facebook, Inc.
  *  All rights reserved.
  *
@@ -37,6 +37,7 @@ public void Register(TinyIoCContainer container)
 			container.Register<IFileCacheHash, FileCacheHash>().AsPerRequestSingleton();
 			container.Register<JsEngineSwitcher>((c, o) => JsEngineSwitcher.Instance);
 			container.Register<IJavaScriptEngineFactory, JavaScriptEngineFactory>().AsSingleton();
+			container.Register<IReactIdGenerator, ReactIdGenerator>().AsSingleton();
 
 			container.Register<IReactEnvironment, ReactEnvironment>().AsPerRequestSingleton();
 		}

src/React.Core/GuidExtensions.cs

@@ -1,4 +1,4 @@
-/*
+/*
  *  Copyright (c) 2016-Present, Facebook, Inc.
  *  All rights reserved.
  *
@@ -7,18 +7,14 @@
  *  of patent rights can be found in the PATENTS file in the same directory.
  */
 
-using System;
-using Xunit;
-
-namespace React.Tests.Core
+namespace React
 {
-	public class GuidExtensionsTests
+	public interface IReactIdGenerator
 	{
-		[Fact]
-		public void ToShortGuid()
-		{
-			var guid = Guid.Parse("c027191d-3785-485d-9fd7-5e0b376bd547");
-			Assert.Equal("HRknwIU3XUif114LN2vVRw", guid.ToShortGuid());
-		}
+		/// <summary>
+		/// Returns a short react identifier starts with "react_".
+		/// </summary>
+		/// <returns></returns>
+		string Generate();
 	}
 }

tests/React.Tests/Core/GuidExtensionsTests.cs renamed to src/React.Core/IReactIdGenerator.cs

@@ -97,15 +97,16 @@ public object Props
 		/// </summary>
 		/// <param name="environment">The environment.</param>
 		/// <param name="configuration">Site-wide configuration.</param>
+		/// <param name="reactIdGenerator">React Id generator.</param>
 		/// <param name="componentName">Name of the component.</param>
 		/// <param name="containerId">The ID of the container DIV for this component</param>
-		public ReactComponent(IReactEnvironment environment, IReactSiteConfiguration configuration, string componentName, string containerId)
+		public ReactComponent(IReactEnvironment environment, IReactSiteConfiguration configuration, IReactIdGenerator reactIdGenerator, string componentName, string containerId)
 		{
 			EnsureComponentNameValid(componentName);
 			_environment = environment;
 			_configuration = configuration;
 			ComponentName = componentName;
-			ContainerId = string.IsNullOrEmpty(containerId) ? GenerateId() : containerId;
+			ContainerId = string.IsNullOrEmpty(containerId) ? reactIdGenerator.Generate() : containerId;
 			ContainerTag = "div";
 		}
 
@@ -229,14 +230,5 @@ internal static void EnsureComponentNameValid(string componentName)
 				throw new ReactInvalidComponentException($"Invalid component name '{componentName}'");
 			}
 		}
-
-		/// <summary>
-		/// Generates a unique identifier for this component, if one was not passed in.
-		/// </summary>
-		/// <returns></returns>
-		private static string GenerateId()
-		{
-			return "react_" + Guid.NewGuid().ToShortGuid();
-		}
 	}
 }

src/React.Core/ReactComponent.cs

@@ -1,4 +1,4 @@
-/*
+/*
  *  Copyright (c) 2014-Present, Facebook, Inc.
  *  All rights reserved.
  *
@@ -55,6 +55,10 @@ public class ReactEnvironment : IReactEnvironment, IDisposable
 		/// Hash algorithm for file-based cache
 		/// </summary>
 		protected readonly IFileCacheHash _fileCacheHash;
+		/// <summary>
+		/// React Id generator
+		/// </summary>
+		private readonly IReactIdGenerator _reactIdGenerator;
 
 		/// <summary>
 		/// JSX Transformer instance for this environment
@@ -120,19 +124,22 @@ public static IReactEnvironment GetCurrentOrThrow
 		/// <param name="cache">The cache to use for JSX compilation</param>
 		/// <param name="fileSystem">File system wrapper</param>
 		/// <param name="fileCacheHash">Hash algorithm for file-based cache</param>
+		/// <param name="reactIdGenerator">React ID generator</param>
 		public ReactEnvironment(
 			IJavaScriptEngineFactory engineFactory,
 			IReactSiteConfiguration config,
 			ICache cache,
 			IFileSystem fileSystem,
-			IFileCacheHash fileCacheHash
+			IFileCacheHash fileCacheHash,
+			IReactIdGenerator reactIdGenerator
 		)
 		{
 			_engineFactory = engineFactory;
 			_config = config;
 			_cache = cache;
 			_fileSystem = fileSystem;
 			_fileCacheHash = fileCacheHash;
+			_reactIdGenerator = reactIdGenerator;
 			_babelTransformer = new Lazy<IBabel>(() => 
 				new Babel(this, _cache, _fileSystem, _fileCacheHash, _config)
 			);
@@ -294,7 +301,7 @@ public virtual IReactComponent CreateComponent<T>(string componentName, T props,
 				EnsureUserScriptsLoaded();
 			}
 
-			var component = new ReactComponent(this, _config, componentName, containerId)
+			var component = new ReactComponent(this, _config, _reactIdGenerator, componentName, containerId)
 			{
 				Props = props,
 				ServerOnly = serverOnly

src/React.Core/ReactEnvironment.cs

@@ -0,0 +1,68 @@
+/*
+ *  Copyright (c) 2016-Present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant 
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+using System;
+using System.Threading;
+
+namespace React
+{
+	/// <summary>
+	/// React ID generator.
+	/// </summary>
+	public class ReactIdGenerator : IReactIdGenerator
+	{
+		private static readonly string _encode32Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
+
+		private static long _random = DateTime.UtcNow.Ticks;
+
+		private static readonly char[] reactPrefix = "react_".ToCharArray();
+
+		/// <summary>
+		/// "react_".Length = 6 + 13 random symbols
+		/// </summary>
+		private const int reactIdLength = 19;
+
+		[ThreadStatic]
+		private static char[] _chars;
+
+		/// <summary>
+		/// Returns a short react identifier starts with "react_".
+		/// </summary>
+		/// <returns></returns>
+		public string Generate()
+		{
+			var chars = _chars;
+			if (chars == null)
+			{
+				_chars = chars = new char[reactIdLength];
+				Array.Copy(reactPrefix, 0, chars, 0, reactPrefix.Length);
+			}
+
+			var id = Interlocked.Increment(ref _random);
+
+			// from 6 because  "react_".Length == 6, _encode32Chars.Length == 32 (base32), 
+			// base32 characters are 5 bits in length and from long (64 bits) we can get 13 symbols
+			chars[6] = _encode32Chars[(int)(id >> 60) & 31];
+			chars[7] = _encode32Chars[(int)(id >> 55) & 31];
+			chars[8] = _encode32Chars[(int)(id >> 50) & 31];
+			chars[9] = _encode32Chars[(int)(id >> 45) & 31];
+			chars[10] = _encode32Chars[(int)(id >> 40) & 31];
+			chars[11] = _encode32Chars[(int)(id >> 35) & 31];
+			chars[12] = _encode32Chars[(int)(id >> 30) & 31];
+			chars[13] = _encode32Chars[(int)(id >> 25) & 31];
+			chars[14] = _encode32Chars[(int)(id >> 20) & 31];
+			chars[15] = _encode32Chars[(int)(id >> 15) & 31];
+			chars[16] = _encode32Chars[(int)(id >> 10) & 31];
+			chars[17] = _encode32Chars[(int)(id >> 5) & 31];
+			chars[18] = _encode32Chars[(int)id & 31];
+
+			return new string(chars, 0, reactIdLength);
+		}
+	}
+}

src/React.Core/ReactIdGenerator.cs

@@ -1,4 +1,4 @@
-/*
+/*
  *  Copyright (c) 2014-Present, Facebook, Inc.
  *  All rights reserved.
  *
@@ -35,11 +35,10 @@ public static ReactRouterComponent CreateRouterComponent<T>(
 			bool clientOnly = false
 		)
 		{
-			var config = AssemblyRegistration.Container.Resolve<IReactSiteConfiguration>();
-
 			var component = new ReactRouterComponent(
-				env, 
-				config, 
+				env,
+				AssemblyRegistration.Container.Resolve<IReactSiteConfiguration>(), 
+				AssemblyRegistration.Container.Resolve<IReactIdGenerator>(),
 				componentName, 
 				containerId, 
 				path

src/React.Router/ReactEnvironmentExtensions.cs

@@ -26,16 +26,18 @@ public class ReactRouterComponent : ReactComponent
 		/// </summary>
 		/// <param name="environment">The environment.</param>
 		/// <param name="configuration">Site-wide configuration.</param>
+		/// <param name="reactIdGenerator">React Id generator.</param>
 		/// <param name="componentName">Name of the component.</param>
 		/// <param name="containerId">The ID of the container DIV for this component</param>
 		/// <param name="path">F.x. from Request.Path. Used by React Static Router to determine context and routing.</param>
 		public ReactRouterComponent(
 			IReactEnvironment environment,
 			IReactSiteConfiguration configuration,
+			IReactIdGenerator reactIdGenerator,
 			string componentName,
 			string containerId,
 			string path
-		) : base(environment, configuration, componentName, containerId)
+		) : base(environment, configuration, reactIdGenerator, componentName, containerId)
 		{
 			_path = path;
 		}