Add async document/element loading for XLinq.

src/System.Xml.XDocument/System.Xml.XDocument.csproj

@@ -1,13 +1,13 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  
-  
+
+
   <PropertyGroup>
     <!-- Work around known Dev14 bug - see
          https://connect.microsoft.com/VisualStudio/feedback/details/1000796/connect-file-uap-props-not-found-cant-build-a-portable-lib-on-vs14
-    --> 
-     
+    -->
+
     <_WindowsKitBinPath>$(MSBuildProgramFiles32)\Windows Kits\8.1\bin\x86</_WindowsKitBinPath>
     <_WindowsPhoneKitBinPath>$(MSBuildProgramFiles32)\Windows Phone Kits\8.1\bin</_WindowsPhoneKitBinPath>
     <MakePriExeFullPath>$(_WindowsKitBinPath)\makepri.exe</MakePriExeFullPath>
@@ -16,8 +16,8 @@
     <MakePriExtensionPath>$(_WindowsPhoneKitBinPath)\x86\MrmEnvironmentExtDl.dll</MakePriExtensionPath>
     <MakePriExtensionPath_x64>$(_WindowsPhoneKitBinPath)\x64\MrmEnvironmentExtDl.dll</MakePriExtensionPath_x64>
   </PropertyGroup>
-  
-  
+
+
   <PropertyGroup>
     <Configuration Condition="'$(Configuration)' == ''">Debug</Configuration>
     <Platform Condition="'$(Platform)' == ''">AnyCPU</Platform>
@@ -61,6 +61,7 @@
     <Reference Include="System.Runtime.Extensions" />
     <!--System.Environment.get_CurrentManagedThreadId-->
     <Reference Include="System.Threading" />
+    <Reference Include="System.Threading.Tasks" />
     <!--For locking-->
     <Reference Include="System.Reflection" />
     <!--Need to reimplement Type.IsInstanceOfType-->

src/System.Xml.XDocument/System/Xml/Linq/XComment.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System.Threading;
+using System.Threading.Tasks;
 namespace System.Xml.Linq
 {
     /// <summary>
@@ -92,6 +94,21 @@ public override void WriteTo(XmlWriter writer)
             writer.WriteComment(value);
         }
 
+        /// <summary>
+        /// Write this <see cref="XComment"/> to the passed in <see cref="XmlWriter"/>.
+        /// </summary>
+        /// <param name="writer">
+        /// The <see cref="XmlWriter"/> to write this <see cref="XComment"/> to.
+        /// </param>
+        /// <param name="cancellationToken">A cancellation token.</param>
+        public override async Task WriteToAsync(XmlWriter writer, CancellationToken cancellationToken)
+        {
+            if (writer == null) throw new ArgumentNullException("writer");
+
+            cancellationToken.ThrowIfCancellationRequested();
+            await writer.WriteCommentAsync(value).ConfigureAwait(false);
+        }
+
         internal override XNode CloneNode()
         {
             return new XComment(this);

src/System.Xml.XDocument/System/Xml/Linq/XDocument.cs

@@ -2,6 +2,8 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 
 using SuppressMessageAttribute = System.Diagnostics.CodeAnalysis.SuppressMessageAttribute;
 using Encoding = System.Text.Encoding;
@@ -267,6 +269,42 @@ public static XDocument Load(Stream stream, LoadOptions options)
             }
         }
 
+        /// <summary>
+        /// Create a new <see cref="XDocument"/> and initialize its underlying XML tree using
+        /// the passed <see cref="Stream"/> parameter.  Optionally whitespace handling
+        /// can be preserved.
+        /// </summary>
+        /// <remarks>
+        /// If LoadOptions.PreserveWhitespace is enabled then
+        /// the underlying <see cref="XmlReaderSettings"/> property <see cref="XmlReaderSettings.IgnoreWhitespace"/>
+        /// is set to false.
+        /// </remarks>
+        /// <param name="stream">
+        /// A <see cref="Stream"/> containing the raw XML to read into the newly
+        /// created <see cref="XDocument"/>.
+        /// </param>
+        /// <param name="options">
+        /// A set of <see cref="LoadOptions"/>.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// A cancellation token.
+        /// </param>
+        /// <returns>
+        /// A new <see cref="XDocument"/> containing the contents of the passed in
+        /// <see cref="Stream"/>.
+        /// </returns>
+        public static async Task<XDocument> LoadAsync(Stream stream, LoadOptions options, CancellationToken cancellationToken)
+        {
+            XmlReaderSettings rs = GetXmlReaderSettings(options);
+
+            rs.Async = true;
+
+            using (XmlReader r = XmlReader.Create(stream, rs))
+            {
+                return await LoadAsync(r, options, cancellationToken).ConfigureAwait(false);
+            }
+        }
+
         /// <summary>
         /// Create a new <see cref="XDocument"/> and initialize its underlying XML tree using
         /// the passed <see cref="TextReader"/> parameter.  
@@ -314,6 +352,42 @@ public static XDocument Load(TextReader textReader, LoadOptions options)
             }
         }
 
+        /// <summary>
+        /// Create a new <see cref="XDocument"/> and initialize its underlying XML tree using
+        /// the passed <see cref="TextReader"/> parameter.  Optionally whitespace handling
+        /// can be preserved.
+        /// </summary>
+        /// <remarks>
+        /// If LoadOptions.PreserveWhitespace is enabled then
+        /// the <see cref="XmlReaderSettings"/> property <see cref="XmlReaderSettings.IgnoreWhitespace"/>
+        /// is set to false.
+        /// </remarks>
+        /// <param name="textReader">
+        /// A <see cref="TextReader"/> containing the raw XML to read into the newly
+        /// created <see cref="XDocument"/>.
+        /// </param>
+        /// <param name="options">
+        /// A set of <see cref="LoadOptions"/>.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// A cancellation token.
+        /// </param>
+        /// <returns>
+        /// A new <see cref="XDocument"/> containing the contents of the passed in
+        /// <see cref="TextReader"/>.
+        /// </returns>
+        public static async Task<XDocument> LoadAsync(TextReader textReader, LoadOptions options, CancellationToken cancellationToken)
+        {
+            XmlReaderSettings rs = GetXmlReaderSettings(options);
+
+            rs.Async = true;
+
+            using (XmlReader r = XmlReader.Create(textReader, rs))
+            {
+                return await LoadAsync(r, options, cancellationToken).ConfigureAwait(false);
+            }
+        }
+
         /// <summary>
         /// Create a new <see cref="XDocument"/> containing the contents of the
         /// passed in <see cref="XmlReader"/>.
@@ -350,6 +424,55 @@ public static XDocument Load(XmlReader reader, LoadOptions options)
         {
             if (reader == null) throw new ArgumentNullException("reader");
             if (reader.ReadState == ReadState.Initial) reader.Read();
+
+            XDocument d = InitLoad(reader, options);
+            d.ReadContentFrom(reader, options);
+
+            if (!reader.EOF) throw new InvalidOperationException(SR.InvalidOperation_ExpectedEndOfFile);
+            if (d.Root == null) throw new InvalidOperationException(SR.InvalidOperation_MissingRoot);
+            return d;
+        }
+
+        /// <summary>
+        /// Create a new <see cref="XDocument"/> containing the contents of the
+        /// passed in <see cref="XmlReader"/>.
+        /// </summary>
+        /// <param name="reader">
+        /// An <see cref="XmlReader"/> containing the XML to be read into the new
+        /// <see cref="XDocument"/>.
+        /// </param>
+        /// <param name="options">
+        /// A set of <see cref="LoadOptions"/>.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// A cancellation token.
+        /// </param>
+        /// <returns>
+        /// A new <see cref="XDocument"/> containing the contents of the passed
+        /// in <see cref="XmlReader"/>.
+        /// </returns>
+        public static async Task<XDocument> LoadAsync(XmlReader reader, LoadOptions options, CancellationToken cancellationToken)
+        {
+            if (reader == null) throw new ArgumentNullException("reader");
+            if (reader.ReadState == ReadState.Initial)
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+                await reader.ReadAsync().ConfigureAwait(false);
+            }
+
+            XDocument d = InitLoad(reader, options);
+            await d.ReadContentFromAsync(reader, options, cancellationToken);
+
+            if (!reader.EOF) throw new InvalidOperationException(SR.InvalidOperation_ExpectedEndOfFile);
+            if (d.Root == null) throw new InvalidOperationException(SR.InvalidOperation_MissingRoot);
+            return d;
+        }
+
+        /// <summary>
+        /// Performs shared initialization between Load and LoadAsync.
+        /// </summary>
+        static XDocument InitLoad(XmlReader reader, LoadOptions options)
+        {
             XDocument d = new XDocument();
             if ((options & LoadOptions.SetBaseUri) != 0)
             {
@@ -371,9 +494,6 @@ public static XDocument Load(XmlReader reader, LoadOptions options)
             {
                 d.Declaration = new XDeclaration(reader);
             }
-            d.ReadContentFrom(reader, options);
-            if (!reader.EOF) throw new InvalidOperationException(SR.InvalidOperation_ExpectedEndOfFile);
-            if (d.Root == null) throw new InvalidOperationException(SR.InvalidOperation_MissingRoot);
             return d;
         }
 
@@ -478,6 +598,40 @@ public void Save(Stream stream, SaveOptions options)
             }
         }
 
+        /// <summary>
+        /// Output this <see cref="XDocument"/> to a <see cref="Stream"/>.
+        /// </summary>
+        /// <param name="stream">
+        /// The <see cref="Stream"/> to output the XML to.  
+        /// </param>
+        /// <param name="options">
+        /// If SaveOptions.DisableFormatting is enabled the output is not indented.
+        /// If SaveOptions.OmitDuplicateNamespaces is enabled duplicate namespace declarations will be removed.
+        /// </param>
+        /// <param name="cancellationToken">A cancellation token.</param>
+        public async Task SaveAsync(Stream stream, SaveOptions options, CancellationToken cancellationToken)
+        {
+            XmlWriterSettings ws = GetXmlWriterSettings(options);
+
+            ws.Async = true;
+
+            if (declaration != null && !string.IsNullOrEmpty(declaration.Encoding))
+            {
+                try
+                {
+                    ws.Encoding = Encoding.GetEncoding(declaration.Encoding);
+                }
+                catch (ArgumentException)
+                {
+                }
+            }
+
+            using (XmlWriter w = XmlWriter.Create(stream, ws))
+            {
+                await WriteToAsync(w, cancellationToken).ConfigureAwait(false);
+            }
+        }
+
         /// <summary>
         /// Output this <see cref="XDocument"/> to the passed in <see cref="TextWriter"/>.
         /// </summary>
@@ -516,6 +670,29 @@ public void Save(TextWriter textWriter, SaveOptions options)
             }
         }
 
+        /// <summary>
+        /// Output this <see cref="XDocument"/> to a <see cref="TextWriter"/>.
+        /// </summary>
+        /// <param name="textWriter">
+        /// The <see cref="TextWriter"/> to output the XML to.  
+        /// </param>
+        /// <param name="options">
+        /// If SaveOptions.DisableFormatting is enabled the output is not indented.
+        /// If SaveOptions.OmitDuplicateNamespaces is enabled duplicate namespace declarations will be removed.
+        /// </param>
+        /// <param name="cancellationToken">A cancellation token.</param>
+        public async Task SaveAsync(TextWriter textWriter, SaveOptions options, CancellationToken cancellationToken)
+        {
+            XmlWriterSettings ws = GetXmlWriterSettings(options);
+
+            ws.Async = true;
+
+            using (XmlWriter w = XmlWriter.Create(textWriter, ws))
+            {
+                await WriteToAsync(w, cancellationToken).ConfigureAwait(false);
+            }
+        }
+
         /// <summary>
         /// Output this <see cref="XDocument"/> to an <see cref="XmlWriter"/>.
         /// </summary>
@@ -527,6 +704,19 @@ public void Save(XmlWriter writer)
             WriteTo(writer);
         }
 
+        /// <summary>
+        /// Output this <see cref="XDocument"/> to an <see cref="XmlWriter"/>.
+        /// </summary>
+        /// <param name="writer">
+        /// The <see cref="XmlWriter"/> to output the XML to.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// A cancellation token.
+        /// </param>
+        public async Task SaveAsync(XmlWriter writer, CancellationToken cancellationToken)
+        {
+            await WriteToAsync(writer, cancellationToken).ConfigureAwait(false);
+        }
 
         /// <summary>
         /// Output this <see cref="XDocument"/>'s underlying XML tree to the
@@ -556,6 +746,42 @@ public override void WriteTo(XmlWriter writer)
             writer.WriteEndDocument();
         }
 
+        /// <summary>
+        /// Output this <see cref="XDocument"/>'s underlying XML tree to the
+        /// passed in <see cref="XmlWriter"/>.
+        /// <seealso cref="XDocument.Save(XmlWriter)"/>
+        /// </summary>
+        /// <param name="writer">
+        /// The <see cref="XmlWriter"/> to output the content of this 
+        /// <see cref="XDocument"/>.
+        /// </param>
+        /// <param name="cancellationToken">A cancellation token.</param>
+        public override async Task WriteToAsync(XmlWriter writer, CancellationToken cancellationToken)
+        {
+            if (writer == null) throw new ArgumentNullException("writer");
+
+            cancellationToken.ThrowIfCancellationRequested();
+
+            Task tStart;
+
+            if (declaration != null && declaration.Standalone == "yes")
+            {
+                tStart = writer.WriteStartDocumentAsync(true);
+            }
+            else if (declaration != null && declaration.Standalone == "no")
+            {
+                tStart = writer.WriteStartDocumentAsync(false);
+            }
+            else
+            {
+                tStart = writer.WriteStartDocumentAsync();
+            }
+
+            await tStart.ConfigureAwait(false);
+            await WriteContentToAsync(writer, cancellationToken).ConfigureAwait(false);
+            await writer.WriteEndDocumentAsync().ConfigureAwait(false);
+        }
+
         internal override void AddAttribute(XAttribute a)
         {
             throw new ArgumentException(SR.Argument_AddAttribute);

src/System.Xml.XDocument/System/Xml/Linq/XDocumentType.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System.Threading;
+using System.Threading.Tasks;
 namespace System.Xml.Linq
 {
     /// <summary>
@@ -142,6 +144,23 @@ public override void WriteTo(XmlWriter writer)
             writer.WriteDocType(name, publicId, systemId, internalSubset);
         }
 
+        /// <summary>
+        /// Write this <see cref="XDocumentType"/> to the passed in <see cref="XmlWriter"/>.
+        /// </summary>
+        /// <param name="writer">
+        /// The <see cref="XmlWriter"/> to write this <see cref="XDocumentType"/> to.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// A cancellation token.
+        /// </param>
+        public override async Task WriteToAsync(XmlWriter writer, CancellationToken cancellationToken)
+        {
+            if (writer == null) throw new ArgumentNullException("writer");
+
+            cancellationToken.ThrowIfCancellationRequested();
+            await writer.WriteDocTypeAsync(name, publicId, systemId, internalSubset).ConfigureAwait(false);
+        }
+
         internal override XNode CloneNode()
         {
             return new XDocumentType(this);