Improve performance and reduce memory use and reduce array allocation…

…s by reusing char[] (#9166)

* Reduce array allocations by reusing char[]

* don't hide .Equals()

* Reduce memory use by reducing array allocations

* Revert "Reduce memory use by reducing array allocations"

This reverts commit faf6b60.

* reuse char[] for string.split() to avoid params [] allocation

src/Umbraco.Core/Composing/TypeFinder.cs

@@ -35,7 +35,7 @@ private static string[] AssembliesAcceptingLoadExceptions
                 var s = ConfigurationManager.AppSettings[Constants.AppSettings.AssembliesAcceptingLoadExceptions];
                 return _assembliesAcceptingLoadExceptions = string.IsNullOrWhiteSpace(s)
                     ? Array.Empty<string>()
-                    : s.Split(',').Select(x => x.Trim()).ToArray();
+                    : s.Split(Constants.CharArrays.Comma).Select(x => x.Trim()).ToArray();
             }
         }
 

src/Umbraco.Core/Configuration/GlobalSettingsExtensions.cs

@@ -44,7 +44,7 @@ internal static string GetUmbracoMvcAreaNoCache(this IGlobalSettings globalSetti
             var path = globalSettings.Path;
             if (path.StartsWith(SystemDirectories.Root)) // beware of TrimStart, see U4-2518
                 path = path.Substring(SystemDirectories.Root.Length);
-            return path.TrimStart('~').TrimStart('/').Replace('/', '-').Trim().ToLower();
+            return path.TrimStart(Constants.CharArrays.Tilde).TrimStart(Constants.CharArrays.ForwardSlash).Replace('/', '-').Trim().ToLower();
         }
 
     }

src/Umbraco.Core/Configuration/UmbracoSettings/ContentSectionExtensions.cs

@@ -15,7 +15,7 @@ public static bool IsImageFile(this IContentSection contentConfig, string extens
         {
             if (contentConfig == null) throw new ArgumentNullException(nameof(contentConfig));
             if (extension == null) return false;
-            extension = extension.TrimStart('.');
+            extension = extension.TrimStart(Constants.CharArrays.Period);
             return contentConfig.ImageFileTypes.InvariantContains(extension);
         }
 

src/Umbraco.Core/Constants-CharArrays.cs

@@ -0,0 +1,138 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Umbraco.Core
+{
+    public static partial class Constants
+    {
+        /// <summary>
+        /// Char Arrays to avoid allocations
+        /// </summary>
+        public static class CharArrays
+        {
+            /// <summary>
+            /// Char array containing only /
+            /// </summary>
+            public static readonly char[] ForwardSlash = new char[] { '/' };
+
+            /// <summary>
+            /// Char array containing only \
+            /// </summary>
+            public static readonly char[] Backslash = new char[] { '\\' };
+
+            /// <summary>
+            /// Char array containing only '
+            /// </summary>
+            public static readonly char[] SingleQuote = new char[] { '\'' };
+
+            /// <summary>
+            /// Char array containing only "
+            /// </summary>
+            public static readonly char[] DoubleQuote = new char[] { '\"' };
+
+
+            /// <summary>
+            /// Char array containing ' "
+            /// </summary>
+            public static readonly char[] DoubleQuoteSingleQuote = new char[] { '\"', '\'' };
+
+            /// <summary>
+            /// Char array containing only _
+            /// </summary>
+            public static readonly char[] Underscore = new char[] { '_' };
+
+            /// <summary>
+            /// Char array containing \n \r
+            /// </summary>
+            public static readonly char[] LineFeedCarriageReturn = new char[] { '\n', '\r' };
+
+
+            /// <summary>
+            /// Char array containing \n
+            /// </summary>
+            public static readonly char[] LineFeed = new char[] { '\n' };
+
+            /// <summary>
+            /// Char array containing only ,
+            /// </summary>
+            public static readonly char[] Comma = new char[] { ',' };
+
+            /// <summary>
+            /// Char array containing only &
+            /// </summary>
+            public static readonly char[] Ampersand = new char[] { '&' };
+
+            /// <summary>
+            /// Char array containing only \0
+            /// </summary>
+            public static readonly char[] NullTerminator = new char[] { '\0' };
+
+            /// <summary>
+            /// Char array containing only .
+            /// </summary>
+            public static readonly char[] Period = new char[] { '.' };
+
+            /// <summary>
+            /// Char array containing only ~
+            /// </summary>
+            public static readonly char[] Tilde = new char[] { '~' };
+            /// <summary>
+            /// Char array containing ~ /
+            /// </summary>
+            public static readonly char[] TildeForwardSlash = new char[] { '~', '/' };
+
+            /// <summary>
+            /// Char array containing only ?
+            /// </summary>
+            public static readonly char[] QuestionMark = new char[] { '?' };
+
+            /// <summary>
+            /// Char array containing ? &
+            /// </summary>
+            public static readonly char[] QuestionMarkAmpersand = new char[] { '?', '&' };
+
+            /// <summary>
+            /// Char array containing XML 1.1 whitespace chars
+            /// </summary>
+            public static readonly char[] XmlWhitespaceChars = new char[] { ' ', '\t', '\r', '\n' };
+
+            /// <summary>
+            /// Char array containing only the Space char
+            /// </summary>
+            public static readonly char[] Space = new char[] { ' ' };
+
+            /// <summary>
+            /// Char array containing only ;
+            /// </summary>
+            public static readonly char[] Semicolon = new char[] { ';' };
+
+            /// <summary>
+            /// Char array containing a comma and a space
+            /// </summary>
+            public static readonly char[] CommaSpace = new char[] { ',', ' ' };
+
+            /// <summary>
+            /// Char array containing  _ -
+            /// </summary>
+            public static readonly char[] UnderscoreDash = new char[] { '_', '-' };
+
+            /// <summary>
+            /// Char array containing =
+            /// </summary>
+            public static readonly char[] EqualsChar = new char[] { '=' };
+
+            /// <summary>
+            /// Char array containing >
+            /// </summary>
+            public static readonly char[] GreaterThan = new char[] { '>' };
+
+            /// <summary>
+            /// Char array containing |
+            /// </summary>
+            public static readonly char[] VerticalTab = new char[] { '|' };
+        }
+    }
+}

src/Umbraco.Core/DictionaryExtensions.cs

@@ -253,7 +253,7 @@ public static string ToQueryString(this IDictionary<string, object> d)
             {
                 builder.Append(String.Format("{0}={1}&", HttpUtility.UrlEncode(i.Key), i.Value == null ? string.Empty : HttpUtility.UrlEncode(i.Value.ToString())));
             }
-            return builder.ToString().TrimEnd('&');
+            return builder.ToString().TrimEnd(Constants.CharArrays.Ampersand);
         }
 
         /// <summary>The get entry ignore case.</summary>

src/Umbraco.Core/GuidUdi.cs

@@ -33,7 +33,7 @@ public GuidUdi(Uri uriValue)
             : base(uriValue)
         {
             Guid guid;
-            if (Guid.TryParse(uriValue.AbsolutePath.TrimStart('/'), out guid) == false)
+            if (Guid.TryParse(uriValue.AbsolutePath.TrimStart(Constants.CharArrays.ForwardSlash), out guid) == false)
                 throw new FormatException("URI \"" + uriValue + "\" is not a GUID entity ID.");
 
             Guid = guid;

src/Umbraco.Core/HttpContextExtensions.cs

@@ -50,7 +50,7 @@ public static string GetCurrentRequestIpAddress(this HttpContextBase httpContext
                 if (string.IsNullOrEmpty(ipAddress))
                     return request.UserHostAddress;
 
-                var addresses = ipAddress.Split(',');
+                var addresses = ipAddress.Split(Constants.CharArrays.Comma);
                 if (addresses.Length != 0)
                     return addresses[0];
 

src/Umbraco.Core/IO/IOHelper.cs

@@ -40,7 +40,7 @@ public static string FindFile(string virtualPath)
                 retval = virtualPath.Replace("~", SystemDirectories.Root);
 
             if (virtualPath.StartsWith("/") && virtualPath.StartsWith(SystemDirectories.Root) == false)
-                retval = SystemDirectories.Root + "/" + virtualPath.TrimStart('/');
+                retval = SystemDirectories.Root + "/" + virtualPath.TrimStart(Constants.CharArrays.ForwardSlash);
 
             return retval;
         }
@@ -98,11 +98,11 @@ public static string MapPath(string path, bool useHttpContext)
                 if (String.IsNullOrEmpty(path) == false && (path.StartsWith("~") || path.StartsWith(SystemDirectories.Root)))
                     return HostingEnvironment.MapPath(path);
                 else
-                    return HostingEnvironment.MapPath("~/" + path.TrimStart('/'));
+                    return HostingEnvironment.MapPath("~/" + path.TrimStart(Constants.CharArrays.ForwardSlash));
             }
 
             var root = GetRootDirectorySafe();
-            var newPath = path.TrimStart('~', '/').Replace('/', IOHelper.DirSepChar);
+            var newPath = path.TrimStart(Constants.CharArrays.TildeForwardSlash).Replace('/', IOHelper.DirSepChar);
             var retval = root + IOHelper.DirSepChar.ToString(CultureInfo.InvariantCulture) + newPath;
 
             return retval;
@@ -121,7 +121,7 @@ internal static string ReturnPath(string settingsKey, string standardPath, bool
             if (string.IsNullOrEmpty(retval))
                 retval = standardPath;
 
-            return retval.TrimEnd('/');
+            return retval.TrimEnd(Constants.CharArrays.ForwardSlash);
         }
 
         internal static string ReturnPath(string settingsKey, string standardPath)
@@ -188,7 +188,7 @@ internal static bool VerifyEditPath(string filePath, IEnumerable<string> validDi
         internal static bool VerifyFileExtension(string filePath, IEnumerable<string> validFileExtensions)
         {
             var ext = Path.GetExtension(filePath);
-            return ext != null && validFileExtensions.Contains(ext.TrimStart('.'));
+            return ext != null && validFileExtensions.Contains(ext.TrimStart(Constants.CharArrays.Period));
         }
 
         public static bool PathStartsWith(string path, string root, char separator)

src/Umbraco.Core/IO/PhysicalFileSystem.cs

@@ -33,7 +33,7 @@ public PhysicalFileSystem(string virtualRoot)
 
             _rootPath = EnsureDirectorySeparatorChar(IOHelper.MapPath(virtualRoot)).TrimEnd(Path.DirectorySeparatorChar);
             _rootPathFwd = EnsureUrlSeparatorChar(_rootPath);
-            _rootUrl = EnsureUrlSeparatorChar(IOHelper.ResolveUrl(virtualRoot)).TrimEnd('/');
+            _rootUrl = EnsureUrlSeparatorChar(IOHelper.ResolveUrl(virtualRoot)).TrimEnd(Constants.CharArrays.ForwardSlash);
         }
 
         public PhysicalFileSystem(string rootPath, string rootUrl)
@@ -54,7 +54,7 @@ public PhysicalFileSystem(string rootPath, string rootUrl)
 
             _rootPath = EnsureDirectorySeparatorChar(rootPath).TrimEnd(Path.DirectorySeparatorChar);
             _rootPathFwd = EnsureUrlSeparatorChar(_rootPath);
-            _rootUrl = EnsureUrlSeparatorChar(rootUrl).TrimEnd('/');
+            _rootUrl = EnsureUrlSeparatorChar(rootUrl).TrimEnd(Constants.CharArrays.ForwardSlash);
         }
 
         /// <summary>
@@ -259,12 +259,12 @@ public string GetRelativePath(string fullPathOrUrl)
             // if it starts with the root URL, strip it and trim the starting slash to make it relative
             // eg "/Media/1234/img.jpg" => "1234/img.jpg"
             if (IOHelper.PathStartsWith(path, _rootUrl, '/'))
-                return path.Substring(_rootUrl.Length).TrimStart('/');
+                return path.Substring(_rootUrl.Length).TrimStart(Constants.CharArrays.ForwardSlash);
 
             // if it starts with the root path, strip it and trim the starting slash to make it relative
             // eg "c:/websites/test/root/Media/1234/img.jpg" => "1234/img.jpg"
             if (IOHelper.PathStartsWith(path, _rootPathFwd, '/'))
-                return path.Substring(_rootPathFwd.Length).TrimStart('/');
+                return path.Substring(_rootPathFwd.Length).TrimStart(Constants.CharArrays.ForwardSlash);
 
             // unchanged - what else?
             return path;
@@ -326,7 +326,7 @@ public string GetFullPath(string path)
         /// <remarks>All separators are forward-slashes.</remarks>
         public string GetUrl(string path)
         {
-            path = EnsureUrlSeparatorChar(path).Trim('/');
+            path = EnsureUrlSeparatorChar(path).Trim(Constants.CharArrays.ForwardSlash);
             return _rootUrl + "/" + path;
         }
 

src/Umbraco.Core/IO/ShadowFileSystem.cs

@@ -182,7 +182,7 @@ public void AddFile(string path, Stream stream, bool overrideIfExists)
             if (Nodes.TryGetValue(normPath, out sf) && sf.IsExist && (sf.IsDir || overrideIfExists == false))
                 throw new InvalidOperationException(string.Format("A file at path '{0}' already exists", path));
 
-            var parts = normPath.Split('/');
+            var parts = normPath.Split(Constants.CharArrays.ForwardSlash);
             for (var i = 0; i < parts.Length - 1; i++)
             {
                 var dirPath = string.Join("/", parts.Take(i + 1));
@@ -297,7 +297,7 @@ public void AddFile(string path, string physicalPath, bool overrideIfExists = tr
             if (Nodes.TryGetValue(normPath, out sf) && sf.IsExist && (sf.IsDir || overrideIfExists == false))
                 throw new InvalidOperationException(string.Format("A file at path '{0}' already exists", path));
 
-            var parts = normPath.Split('/');
+            var parts = normPath.Split(Constants.CharArrays.ForwardSlash);
             for (var i = 0; i < parts.Length - 1; i++)
             {
                 var dirPath = string.Join("/", parts.Take(i + 1));

src/Umbraco.Core/Migrations/Install/DatabaseBuilder.cs

@@ -354,7 +354,7 @@ internal bool IsConnectionStringConfigured(ConnectionStringSettings databaseSett
             var sqlCeDatabaseExists = false;
             if (dbIsSqlCe)
             {
-                var parts = databaseSettings.ConnectionString.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
+                var parts = databaseSettings.ConnectionString.Split(Constants.CharArrays.Semicolon, StringSplitOptions.RemoveEmptyEntries);
                 var dataSourcePart = parts.FirstOrDefault(x => x.InvariantStartsWith("Data Source="));
                 if (dataSourcePart != null)
                 {

src/Umbraco.Core/Migrations/Upgrade/V_8_0_0/PropertyEditorsMigrationBase.cs

@@ -30,7 +30,7 @@ internal List<DataTypeDto> GetDataTypes(string editorAlias, bool strict = true)
 
         protected int[] ConvertStringValues(string val)
         {
-            var splitVals = val.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+            var splitVals = val.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries);
 
             var intVals = splitVals
                 .Select(x => int.TryParse(x, out var i) ? i : int.MinValue)

src/Umbraco.Core/Models/PathValidationExtensions.cs

@@ -25,7 +25,7 @@ public static void ValidatePathWithException(this NodeDto entity)
             if (entity.Path.IsNullOrWhiteSpace())
                 throw new InvalidDataException($"The content item {entity.NodeId} has an empty path: {entity.Path} with parentID: {entity.ParentId}");
 
-            var pathParts = entity.Path.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+            var pathParts = entity.Path.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries);
             if (pathParts.Length < 2)
             {
                 //a path cannot be less than 2 parts, at a minimum it must be root (-1) and it's own id
@@ -53,7 +53,7 @@ public static bool ValidatePath(this IUmbracoEntity entity)
             if (entity.Path.IsNullOrWhiteSpace())
                 return false;
 
-            var pathParts = entity.Path.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+            var pathParts = entity.Path.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries);
             if (pathParts.Length < 2)
             {
                 //a path cannot be less than 2 parts, at a minimum it must be root (-1) and it's own id

src/Umbraco.Core/Packaging/PackageDataInstallation.cs

@@ -522,7 +522,7 @@ private Dictionary<string, int> CreateContentTypeFolderStructure(IEnumerable<XEl
                     && ((string)infoElement.Element("Master")).IsNullOrWhiteSpace())
                 {
                     var alias = documentType.Element("Info").Element("Alias").Value;
-                    var folders = foldersAttribute.Value.Split('/');
+                    var folders = foldersAttribute.Value.Split(Constants.CharArrays.ForwardSlash);
                     var rootFolder = HttpUtility.UrlDecode(folders[0]);
                     //level 1 = root level folders, there can only be one with the same name
                     var current = _contentTypeService.GetContainers(rootFolder, 1).FirstOrDefault();
@@ -942,7 +942,7 @@ private Dictionary<string, int> CreateDataTypeFolderStructure(IEnumerable<XEleme
                 if (foldersAttribute != null)
                 {
                     var name = datatypeElement.Attribute("Name").Value;
-                    var folders = foldersAttribute.Value.Split('/');
+                    var folders = foldersAttribute.Value.Split(Constants.CharArrays.ForwardSlash);
                     var rootFolder = HttpUtility.UrlDecode(folders[0]);
                     //there will only be a single result by name for level 1 (root) containers
                     var current = _dataTypeService.GetContainers(rootFolder, 1).FirstOrDefault();

src/Umbraco.Core/Packaging/PackageDefinitionXmlParser.cs

@@ -44,13 +44,13 @@ public PackageDefinition ToPackageDefinition(XElement xml)
                 Actions = xml.Element("actions")?.ToString(SaveOptions.None) ?? "<actions></actions>", //take the entire outer xml value
                 ContentNodeId = xml.Element("content")?.AttributeValue<string>("nodeId") ?? string.Empty,
                 ContentLoadChildNodes = xml.Element("content")?.AttributeValue<bool>("loadChildNodes") ?? false,
-                Macros = xml.Element("macros")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
-                Templates = xml.Element("templates")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
-                Stylesheets = xml.Element("stylesheets")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
-                DocumentTypes = xml.Element("documentTypes")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
-                Languages = xml.Element("languages")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
-                DictionaryItems = xml.Element("dictionaryitems")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
-                DataTypes = xml.Element("datatypes")?.Value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                Macros = xml.Element("macros")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                Templates = xml.Element("templates")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                Stylesheets = xml.Element("stylesheets")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                DocumentTypes = xml.Element("documentTypes")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                Languages = xml.Element("languages")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                DictionaryItems = xml.Element("dictionaryitems")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
+                DataTypes = xml.Element("datatypes")?.Value.Split(Constants.CharArrays.Comma, StringSplitOptions.RemoveEmptyEntries).ToList() ?? new List<string>(),
                 Files = xml.Element("files")?.Elements("file").Select(x => x.Value).ToList() ?? new List<string>()
             };