diff options
Diffstat (limited to 'csharp/src/ProtocolBuffers.Serialization/XmlFormatReader.cs')
| -rw-r--r-- | csharp/src/ProtocolBuffers.Serialization/XmlFormatReader.cs | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/csharp/src/ProtocolBuffers.Serialization/XmlFormatReader.cs b/csharp/src/ProtocolBuffers.Serialization/XmlFormatReader.cs new file mode 100644 index 00000000..a4f111d4 --- /dev/null +++ b/csharp/src/ProtocolBuffers.Serialization/XmlFormatReader.cs @@ -0,0 +1,338 @@ +using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Xml;
+using System.Diagnostics;
+
+namespace Google.ProtocolBuffers.Serialization
+{
+ /// <summary>
+ /// Parses a proto buffer from an XML document or fragment. .NET 3.5 users may also
+ /// use this class to process Json by setting the options to support Json and providing
+ /// an XmlReader obtained from <see cref="System.Runtime.Serialization.Json.JsonReaderWriterFactory"/>.
+ /// </summary>
+ public class XmlFormatReader : AbstractTextReader
+ {
+ public const string DefaultRootElementName = XmlFormatWriter.DefaultRootElementName;
+ private readonly XmlReader _input;
+ // Tracks the message element for each nested message read
+ private readonly Stack<ElementStackEntry> _elements;
+ // The default element name for ReadMessageStart
+ private string _rootElementName;
+
+ private struct ElementStackEntry
+ {
+ public readonly string LocalName;
+ public readonly int Depth;
+ public readonly bool IsEmpty;
+
+ public ElementStackEntry(string localName, int depth, bool isEmpty) : this()
+ {
+ LocalName = localName;
+ IsEmpty = isEmpty;
+ Depth = depth;
+ }
+ }
+
+ private static XmlReaderSettings DefaultSettings
+ {
+ get
+ {
+ return new XmlReaderSettings()
+ {CheckCharacters = false, IgnoreComments = true, IgnoreProcessingInstructions = true};
+ }
+ }
+
+ /// <summary>
+ /// Constructs the XmlFormatReader using the stream provided as the xml
+ /// </summary>
+ public static XmlFormatReader CreateInstance(byte[] input)
+ {
+ return new XmlFormatReader(XmlReader.Create(new MemoryStream(input, false), DefaultSettings));
+ }
+
+ /// <summary>
+ /// Constructs the XmlFormatReader using the stream provided as the xml
+ /// </summary>
+ public static XmlFormatReader CreateInstance(Stream input)
+ {
+ return new XmlFormatReader(XmlReader.Create(input, DefaultSettings));
+ }
+
+ /// <summary>
+ /// Constructs the XmlFormatReader using the string provided as the xml to be read
+ /// </summary>
+ public static XmlFormatReader CreateInstance(String input)
+ {
+ return new XmlFormatReader(XmlReader.Create(new StringReader(input), DefaultSettings));
+ }
+
+ /// <summary>
+ /// Constructs the XmlFormatReader using the xml in the TextReader
+ /// </summary>
+ public static XmlFormatReader CreateInstance(TextReader input)
+ {
+ return new XmlFormatReader(XmlReader.Create(input, DefaultSettings));
+ }
+
+ /// <summary>
+ /// Constructs the XmlFormatReader with the XmlReader
+ /// </summary>
+ public static XmlFormatReader CreateInstance(XmlReader input)
+ {
+ return new XmlFormatReader(input);
+ }
+
+ /// <summary>
+ /// Constructs the XmlFormatReader with the XmlReader and options
+ /// </summary>
+ protected XmlFormatReader(XmlReader input)
+ {
+ _input = input;
+ _rootElementName = DefaultRootElementName;
+ _elements = new Stack<ElementStackEntry>();
+ Options = XmlReaderOptions.None;
+ }
+
+ /// <summary>
+ /// Gets or sets the options to use when reading the xml
+ /// </summary>
+ public XmlReaderOptions Options { get; set; }
+
+ /// <summary>
+ /// Sets the options to use while generating the XML
+ /// </summary>
+ public XmlFormatReader SetOptions(XmlReaderOptions options)
+ {
+ Options = options;
+ return this;
+ }
+
+ /// <summary>
+ /// Gets or sets the default element name to use when using the Merge<TBuilder>()
+ /// </summary>
+ public string RootElementName
+ {
+ get { return _rootElementName; }
+ set
+ {
+ ThrowHelper.ThrowIfNull(value, "RootElementName");
+ _rootElementName = value;
+ }
+ }
+
+ [DebuggerNonUserCode]
+ private static void Assert(bool cond)
+ {
+ if (!cond)
+ {
+ throw new FormatException();
+ }
+ }
+
+ /// <summary>
+ /// Reads the root-message preamble specific to this formatter
+ /// </summary>
+ public override void ReadMessageStart()
+ {
+ ReadMessageStart(_rootElementName);
+ }
+
+ /// <summary>
+ /// Reads the root-message preamble specific to this formatter
+ /// </summary>
+ public void ReadMessageStart(string element)
+ {
+ while (!_input.IsStartElement() && _input.Read())
+ {
+ continue;
+ }
+ Assert(_input.IsStartElement() && _input.LocalName == element);
+ _elements.Push(new ElementStackEntry(element, _input.Depth, _input.IsEmptyElement));
+ _input.Read();
+ }
+
+ /// <summary>
+ /// Reads the root-message close specific to this formatter, MUST be called
+ /// on the reader obtained from ReadMessageStart(string element).
+ /// </summary>
+ public override void ReadMessageEnd()
+ {
+ Assert(_elements.Count > 0);
+
+ ElementStackEntry stop = _elements.Peek();
+ while (_input.NodeType != XmlNodeType.EndElement && _input.NodeType != XmlNodeType.Element
+ && _input.Depth > stop.Depth && _input.Read())
+ {
+ continue;
+ }
+
+ if (!stop.IsEmpty)
+ {
+ Assert(_input.NodeType == XmlNodeType.EndElement
+ && _input.LocalName == stop.LocalName
+ && _input.Depth == stop.Depth);
+
+ _input.Read();
+ }
+ _elements.Pop();
+ }
+
+ /// <summary>
+ /// Merge the provided builder as an element named <see cref="RootElementName"/> in the current context
+ /// </summary>
+ public override TBuilder Merge<TBuilder>(TBuilder builder, ExtensionRegistry registry)
+ {
+ return Merge(_rootElementName, builder, registry);
+ }
+
+ /// <summary>
+ /// Merge the provided builder as an element of the current context
+ /// </summary>
+ public TBuilder Merge<TBuilder>(string element, TBuilder builder) where TBuilder : IBuilderLite
+ {
+ return Merge(element, builder, ExtensionRegistry.Empty);
+ }
+
+ /// <summary>
+ /// Merge the provided builder as an element of the current context
+ /// </summary>
+ public TBuilder Merge<TBuilder>(string element, TBuilder builder, ExtensionRegistry registry)
+ where TBuilder : IBuilderLite
+ {
+ ReadMessageStart(element);
+ builder.WeakMergeFrom(this, registry);
+ ReadMessageEnd();
+ return builder;
+ }
+
+ /// <summary>
+ /// Peeks at the next field in the input stream and returns what information is available.
+ /// </summary>
+ /// <remarks>
+ /// This may be called multiple times without actually reading the field. Only after the field
+ /// is either read, or skipped, should PeekNext return a different value.
+ /// </remarks>
+ protected override bool PeekNext(out string field)
+ {
+ ElementStackEntry stopNode;
+ if (_elements.Count == 0)
+ {
+ stopNode = new ElementStackEntry(null, _input.Depth - 1, false);
+ }
+ else
+ {
+ stopNode = _elements.Peek();
+ }
+
+ if (!stopNode.IsEmpty)
+ {
+ while (!_input.IsStartElement() && _input.Depth > stopNode.Depth && _input.Read())
+ {
+ continue;
+ }
+
+ if (_input.IsStartElement() && _input.Depth > stopNode.Depth)
+ {
+ field = _input.LocalName;
+ return true;
+ }
+ }
+ field = null;
+ return false;
+ }
+
+ /// <summary>
+ /// Causes the reader to skip past this field
+ /// </summary>
+ protected override void Skip()
+ {
+ if (_input.IsStartElement())
+ {
+ if (!_input.IsEmptyElement)
+ {
+ int depth = _input.Depth;
+ while (_input.Depth >= depth && _input.NodeType != XmlNodeType.EndElement)
+ {
+ Assert(_input.Read());
+ }
+ }
+ _input.Read();
+ }
+ }
+
+ /// <summary>
+ /// returns true if it was able to read a single value into the value reference. The value
+ /// stored may be of type System.String, System.Int32, or an IEnumLite from the IEnumLiteMap.
+ /// </summary>
+ protected override bool ReadEnum(ref object value)
+ {
+ int number;
+ string temp;
+ if (null != (temp = _input.GetAttribute("value")) && FrameworkPortability.TryParseInt32(temp, out number))
+ {
+ Skip();
+ value = number;
+ return true;
+ }
+ return base.ReadEnum(ref value);
+ }
+
+ /// <summary>
+ /// Returns true if it was able to read a String from the input
+ /// </summary>
+ protected override bool ReadAsText(ref string value, Type type)
+ {
+ Assert(_input.NodeType == XmlNodeType.Element);
+ value = _input.ReadElementContentAsString();
+
+ return true;
+ }
+
+ /// <summary>
+ /// Merges the input stream into the provided IBuilderLite
+ /// </summary>
+ protected override bool ReadMessage(IBuilderLite builder, ExtensionRegistry registry)
+ {
+ Assert(_input.IsStartElement());
+ ReadMessageStart(_input.LocalName);
+ builder.WeakMergeFrom(this, registry);
+ ReadMessageEnd();
+ return true;
+ }
+
+ private IEnumerable<string> NonNestedArrayItems(string field)
+ {
+ return base.ForeachArrayItem(field);
+ }
+
+ /// <summary>
+ /// Cursors through the array elements and stops at the end of the array
+ /// </summary>
+ protected override IEnumerable<string> ForeachArrayItem(string field)
+ {
+ bool isNested = (Options & XmlReaderOptions.ReadNestedArrays) != 0;
+
+ if (!isNested)
+ {
+ foreach (string item in NonNestedArrayItems(field))
+ {
+ yield return item;
+ }
+ }
+ else
+ {
+ string found;
+ ReadMessageStart(field);
+ if (PeekNext(out found) && found == "item")
+ {
+ foreach (string item in NonNestedArrayItems("item"))
+ {
+ yield return item;
+ }
+ }
+ ReadMessageEnd();
+ }
+ }
+ }
+}
\ No newline at end of file |