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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
// Description:
// An AnnotationStore subclass based on XML streams. Processes XML
// streams and returns CAF 2.0 OM objects. Useful to other
// AnnotationStore subclass who can get an XML stream of their
// content.
// Spec: CAF Storage Spec.doc
//
using System.IO;
using System.Xml;
using System.Xml.XPath;
using MS.Internal;
using MS.Internal.Annotations;
using MS.Internal.Annotations.Storage;
using MS.Utility;
using System.Windows.Markup;
namespace System.Windows.Annotations.Storage
{
/// <summary>
/// An AnnotationStore subclass based on XML streams. Processes XML
/// streams and returns CAF 2.0 OM objects. Useful to other
/// AnnotationStore subclass who can get an XML stream of their
/// content.
/// </summary>
public sealed class XmlStreamStore : AnnotationStore
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
/// <summary>
/// This ctor initializes the Dictionary with predefined namespases
/// and their compatibility
/// </summary>
static XmlStreamStore()
{
_predefinedNamespaces = new Dictionary<Uri, IList<Uri>>(6);
_predefinedNamespaces.Add(new Uri(AnnotationXmlConstants.Namespaces.CoreSchemaNamespace), null);
_predefinedNamespaces.Add(new Uri(AnnotationXmlConstants.Namespaces.BaseSchemaNamespace), null);
_predefinedNamespaces.Add(new Uri(XamlReaderHelper.DefaultNamespaceURI), null);
}
/// <summary>
/// Creates an instance using the XML stream passed in as the
/// content. The XML in the stream must be valid XML and conform
/// to the CAF 2.0 schema.
/// </summary>
/// <param name="stream">stream containing annotation data in XML format</param>
/// <exception cref="ArgumentNullException">stream is null</exception>
/// <exception cref="XmlException">stream contains invalid XML</exception>
public XmlStreamStore(Stream stream)
: base()
{
ArgumentNullException.ThrowIfNull(stream);
if (!stream.CanSeek)
throw new ArgumentException(SR.StreamDoesNotSupportSeek);
SetStream(stream, null);
}
/// <summary>
/// Creates an instance using the XML stream passed in as the
/// content. The XML in the stream must be valid XML and conform
/// to the Annotations V1 schema or a valid future version XML which
/// compatibility rules are that when applied they will produce
/// a valid Annotations V1 XML. This .ctor allows registration of
/// application specific known namespaces.
/// </summary>
/// <param name="stream">stream containing annotation data in XML format</param>
/// <param name="knownNamespaces">A dictionary with known and compatible namespaces. The keys in
/// this dictionary are known namespaces. The value of each key is a list of namespaces that are compatible with
/// the key one, i.e. each of the namespaces in the value list will be transformed to the
/// key namespace while reading the input XML.</param>
/// <exception cref="ArgumentNullException">stream is null</exception>
/// <exception cref="XmlException">stream contains invalid XML</exception>
/// <exception cref="ArgumentException">duplicate namespace in knownNamespaces dictionary</exception>
/// <exception cref="ArgumentException">null key in knownNamespaces dictionary</exception>
public XmlStreamStore(Stream stream, IDictionary<Uri, IList<Uri>> knownNamespaces)
: base()
{
ArgumentNullException.ThrowIfNull(stream);
SetStream(stream, knownNamespaces);
}
#endregion Constructors
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Add a new annotation to this store. The new annotation's Id
/// is set to a new value.
/// </summary>
/// <param name="newAnnotation">the annotation to be added to the store</param>
/// <exception cref="ArgumentNullException">newAnnotation is null</exception>
/// <exception cref="ArgumentException">newAnnotation already exists in this store, as determined by its Id</exception>
/// <exception cref="InvalidOperationException">if no stream has been set on the store</exception>
/// <exception cref="ObjectDisposedException">if object has been Disposed</exception>
public override void AddAnnotation(Annotation newAnnotation)
{
ArgumentNullException.ThrowIfNull(newAnnotation);
// We are going to modify internal data. Lock the object
// to avoid modifications from other threads
lock (SyncRoot)
{
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.AddAnnotationBegin);
try
{
CheckStatus();
XPathNavigator editor = GetAnnotationNodeForId(newAnnotation.Id);
// we are making sure that the newAnnotation doesn't already exist in the store
if (editor != null)
throw new ArgumentException(SR.AnnotationAlreadyExists, "newAnnotation");
// we are making sure that the newAnnotation doesn't already exist in the store map
if (_storeAnnotationsMap.FindAnnotation(newAnnotation.Id) != null)
throw new ArgumentException(SR.AnnotationAlreadyExists, "newAnnotation");
// simply add the annotation to the map to save on performance
// notice that we need to tell the map that this instance of the annotation is dirty
_storeAnnotationsMap.AddAnnotation(newAnnotation, true);
}
finally
{
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.AddAnnotationEnd);
}
}
OnStoreContentChanged(new StoreContentChangedEventArgs(StoreContentAction.Added, newAnnotation));
}
/// <summary>
/// Delete the specified annotation.
/// </summary>
/// <param name="annotationId">the Id of the annotation to be deleted</param>
/// <returns>the annotation that was deleted, or null if no annotation
/// with the specified Id was found</returns>
/// <exception cref="InvalidOperationException">if no stream has been set on the store</exception>
/// <exception cref="ObjectDisposedException">if object has been disposed</exception>
public override Annotation DeleteAnnotation(Guid annotationId)
{
Annotation annotation = null;
// We are now going to modify internal data. Lock the object
// to avoid modifications from other threads
lock (SyncRoot)
{
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.DeleteAnnotationBegin);
try
{
CheckStatus();
annotation = _storeAnnotationsMap.FindAnnotation(annotationId);
XPathNavigator editor = GetAnnotationNodeForId(annotationId);
if (editor != null)
{
// Only deserialize the annotation if its not already in our map
if (annotation == null)
{
annotation = (Annotation)_serializer.Deserialize(editor.ReadSubtree());
}
editor.DeleteSelf();
}
// Remove the instance from the map
_storeAnnotationsMap.RemoveAnnotation(annotationId);
// notice that in Add we add the annotation to the map only
// but in delete we delete it from both to the Xml and the map
}
finally
{
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.DeleteAnnotationEnd);
}
}
// Only fire notification if we actually removed an annotation
if (annotation != null)
{
OnStoreContentChanged(new StoreContentChangedEventArgs(StoreContentAction.Deleted, annotation));
}
return annotation;
}
/// <summary>
/// Queries the Xml stream for annotations that have an anchor
/// that contains a locator that begins with the locator parts
/// in anchorLocator.
/// </summary>
/// <param name="anchorLocator">the locator we are looking for</param>
/// <returns>
/// A list of annotations that have locators in their anchors
/// starting with the same locator parts list as of the input locator
/// If no such annotations an empty list will be returned. The method
/// never returns null.
/// </returns>
/// <exception cref="ObjectDisposedException">if object has been Disposed</exception>
/// <exception cref="InvalidOperationException">the stream is null</exception>
public override IList<Annotation> GetAnnotations(ContentLocator anchorLocator)
{
// First we generate the XPath expression
ArgumentNullException.ThrowIfNull(anchorLocator);
if (anchorLocator.Parts == null)
throw new ArgumentNullException("anchorLocator.Parts");
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.GetAnnotationByLocBegin);
IList<Annotation> annotations = null;
try
{
string query = $@"//{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:{AnnotationXmlConstants.Elements.ContentLocator}";
if (anchorLocator.Parts.Count > 0)
{
query += @"/child::*[1]/self::";
for (int i = 0; i < anchorLocator.Parts.Count; i++)
{
if (anchorLocator.Parts[i] != null)
{
if (i > 0)
{
query += @"/following-sibling::";
}
string fragment = anchorLocator.Parts[i].GetQueryFragment(_namespaceManager);
if (fragment != null)
{
query += fragment;
}
else
{
query += "*";
}
}
}
}
query += $@"/ancestor::{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:Anchors/ancestor::{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:Annotation";
annotations = InternalGetAnnotations(query, anchorLocator);
}
finally
{
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.GetAnnotationByLocEnd);
}
return annotations;
}
/// <summary>
/// Returns a list of all annotations in the store
/// </summary>
/// <returns>annotations list. Can return an empty list, but never null.</returns>
/// <exception cref="ObjectDisposedException">if object has been disposed</exception>
public override IList<Annotation> GetAnnotations()
{
IList<Annotation> annotations = null;
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.GetAnnotationsBegin);
try
{
string query = $"//{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:Annotation";
annotations = InternalGetAnnotations(query, null);
}
finally
{
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.GetAnnotationsEnd);
}
return annotations;
}
/// <summary>
/// Finds annotation by Id
/// </summary>
/// <param name="annotationId">annotation id</param>
/// <returns>The annotation. Null if the annotation does not exists</returns>
/// <exception cref="ObjectDisposedException">if object has been disposed</exception>
public override Annotation GetAnnotation(Guid annotationId)
{
lock (SyncRoot)
{
Annotation annotation = null;
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.GetAnnotationByIdBegin);
try
{
CheckStatus();
annotation = _storeAnnotationsMap.FindAnnotation(annotationId);
// If there is no pre-existing instance, we deserialize and create an instance.
if (annotation != null)
{
return annotation;
}
XPathNavigator editor = GetAnnotationNodeForId(annotationId);
if (editor != null)
{
annotation = (Annotation)_serializer.Deserialize(editor.ReadSubtree());
// Add the new instance to the map
_storeAnnotationsMap.AddAnnotation(annotation, false);
}
}
finally
{
//fire trace event
EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordAnnotation, EventTrace.Event.GetAnnotationByIdEnd);
}
return annotation;
}
}
/// <summary>
/// Causes any buffered data to be written to the underlying
/// storage mechanism. Gets called after each operation if
/// AutoFlush is set to true. The stream is truncated to
/// the length of the data written out by the store.
/// </summary>
/// <exception cref="UnauthorizedAccessException">stream cannot be written to</exception>
/// <exception cref="InvalidOperationException">if no stream has been set on the store</exception>
/// <exception cref="ObjectDisposedException">if object has been disposed</exception>
/// <seealso cref="AutoFlush"/>
public override void Flush()
{
lock (SyncRoot)
{
CheckStatus();
if (!_stream.CanWrite)
{
throw new UnauthorizedAccessException(SR.StreamCannotBeWritten);
}
if (_dirty)
{
SerializeAnnotations();
_stream.Position = 0;
_stream.SetLength(0);
_document.PreserveWhitespace = true;
_document.Save(_stream);
_stream.Flush();
_dirty = false;
}
}
}
/// <summary>
/// Returns a list of namespaces that are compatible with an input namespace
/// </summary>
/// <param name="name">namespace</param>
/// <returns>a list of compatible namespaces. Can be null</returns>
/// <remarks>This method works only with built-in AnnotationFramework namespaces.
/// For any other input namespace the return value will be null even if it is
/// registered with the XmlStreamStore ctor</remarks>
public static IList<Uri> GetWellKnownCompatibleNamespaces(Uri name)
{
ArgumentNullException.ThrowIfNull(name);
if (_predefinedNamespaces.ContainsKey(name))
return _predefinedNamespaces[name];
return null;
}
#endregion Public Methods
//------------------------------------------------------
//
// Public Operators
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
#region Public Properties
/// <summary>
/// When set to true an implementation should call Flush()
/// as a side-effect after each operation.
/// </summary>
/// <value>
/// true if the implementation is set to call Flush() after
/// each operation; false otherwise
/// </value>
public override bool AutoFlush
{
get
{
lock (SyncRoot)
{
return _autoFlush;
}
}
set
{
lock (SyncRoot)
{
_autoFlush = value;
// Commit anything that needs to be committed up to this point
if (_autoFlush)
{
Flush();
}
}
}
}
/// <summary>
/// Returns a list of the namespaces that are ignored while loading
/// the Xml stream
/// </summary>
/// <remarks>The value is never null, but can be an empty list if nothing has been ignored</remarks>
public IList<Uri> IgnoredNamespaces
{
get
{
return _ignoredNamespaces;
}
}
/// <summary>
/// Returns a list of all namespaces that are internaly used by the framework
/// </summary>
public static IList<Uri> WellKnownNamespaces
{
get
{
Uri[] res = new Uri[_predefinedNamespaces.Keys.Count];
_predefinedNamespaces.Keys.CopyTo(res, 0);
return res;
}
}
#endregion Public Properties
//------------------------------------------------------
//
// Protected Methods
//
//------------------------------------------------------
#region Protected Methods
/// <summary>
/// Disposes of the resources (other than memory) used by the store.
/// </summary>
/// <param name="disposing">true to release both managed and unmanaged
/// resources; false to release only unmanaged resources</param>
protected override void Dispose(bool disposing)
{
//call the base class first to set _disposed to false
//in order to avoid working with the store when the resources
//are released
base.Dispose(disposing);
if (disposing)
{
Cleanup();
}
}
/// <summary>
/// Called after every annotation action on the store. We override it
/// to update the dirty state of the store.
/// </summary>
/// <param name="e">arguments for the event to fire</param>
protected override void OnStoreContentChanged(StoreContentChangedEventArgs e)
{
lock (SyncRoot)
{
_dirty = true;
}
base.OnStoreContentChanged(e);
}
#endregion Protected Methods
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
/// <summary>
/// Applies the specified XPath expression to the store and returns
/// the results.
/// </summary>
/// <param name="queryExpression">the XPath expression to be applied to the store</param>
/// <returns>
/// An IList containing zero or more annotations that match the
/// criteria in the XPath expression; never will return null. If
/// no annotations meet the criteria, an empty list is returned.
/// </returns>
/// <exception cref="InvalidOperationException">if no stream has been set on the store</exception>
/// <exception cref="ObjectDisposedException">if object has been Disposed</exception>
/// <exception cref="ArgumentNullException">queryExpression is null</exception>
/// <exception cref="ArgumentException">queryExpression is empty string</exception>
private List<Guid> FindAnnotationIds(string queryExpression)
{
Invariant.Assert(queryExpression != null && queryExpression.Length > 0,
"Invalid query expression");
Guid annId;
List<Guid> retObj = null;
// Lock the object so nobody can change the document
// while the query is executed
lock (SyncRoot)
{
CheckStatus();
XPathNavigator navigator = _document.CreateNavigator();
XPathNodeIterator iterator = navigator.Select(queryExpression, _namespaceManager);
if (iterator != null && iterator.Count > 0)
{
retObj = new List<Guid>(iterator.Count);
foreach (XPathNavigator node in iterator)
{
string nodeId = node.GetAttribute("Id", "");
if (String.IsNullOrEmpty(nodeId))
{
throw new XmlException(SR.Format(SR.RequiredAttributeMissing, AnnotationXmlConstants.Attributes.Id, AnnotationXmlConstants.Elements.Annotation));
}
try
{
annId = XmlConvert.ToGuid(nodeId);
}
catch (FormatException fe)
{
throw new InvalidOperationException(SR.CannotParseId, fe);
}
retObj.Add(annId);
}
}
else
{
retObj = new List<Guid>(0);
}
}
return retObj;
}
/// <summary>
/// Used as AuthorChanged event handler for all annotations
/// handed out by the map.
/// </summary>
/// <param name="sender">annotation that sent the event</param>
/// <param name="e">args for the event</param>
private void HandleAuthorChanged(object sender, AnnotationAuthorChangedEventArgs e)
{
lock (SyncRoot)
{
_dirty = true;
}
OnAuthorChanged(e);
}
/// <summary>
/// Used as AnchorChanged event handler for all annotations
/// handed out by the map.
/// </summary>
/// <param name="sender">annotation that sent the event</param>
/// <param name="e">args for the event</param>
private void HandleAnchorChanged(object sender, AnnotationResourceChangedEventArgs e)
{
lock (SyncRoot)
{
_dirty = true;
}
OnAnchorChanged(e);
}
/// <summary>
/// Used as CargoChanged event handler for all annotations
/// handed out by the map.
/// </summary>
/// <param name="sender">annotation that sent the event</param>
/// <param name="e">args for the event</param>
private void HandleCargoChanged(object sender, AnnotationResourceChangedEventArgs e)
{
lock (SyncRoot)
{
_dirty = true;
}
OnCargoChanged(e);
}
/// <summary>
/// 1- Merge Annotations queried from both the map and the Xml stream
/// 2- Add the annotations found in the Xml stream to the map
/// </summary>
/// <param name="mapAnnotations">A dictionary of map annotations</param>
/// <param name="storeAnnotationsId">A list of annotation ids from the Xml stream</param>
/// <returns></returns>
private IList<Annotation> MergeAndCacheAnnotations(Dictionary<Guid, Annotation> mapAnnotations, List<Guid> storeAnnotationsId)
{
// first put all annotations from the map in the return list
List<Annotation> annotations = new List<Annotation>((IEnumerable<Annotation>)mapAnnotations.Values);
// there three possible conditions
// 1- An annotation exists in xml and in the store map results
// 2- An annotation exists in xml and not in the store map results
// 2-1- The annotation is found in the map
// 2-2- The annotation is not found in the map
// Now, we need to find annotations in the store that are not in the map results
// and verify that they should be serialized
foreach (Guid annotationId in storeAnnotationsId)
{
Annotation annot;
bool foundInMapResults = mapAnnotations.TryGetValue(annotationId, out annot);
if (!foundInMapResults)
{
// it is not in the map - get it from the store
annot = GetAnnotation(annotationId);
annotations.Add(annot);
}
}
return annotations;
}
/// <summary>
/// Do the GetAnnotations work inside a lock statement for thread safety reasons
/// </summary>
/// <param name="query"></param>
/// <param name="anchorLocator"></param>
/// <returns></returns>
private IList<Annotation> InternalGetAnnotations(string query, ContentLocator anchorLocator)
{
// anchorLocator being null is handled appropriately below
Invariant.Assert(query != null, "Parameter 'query' is null.");
lock (SyncRoot)
{
CheckStatus();
List<Guid> annotationIds = FindAnnotationIds(query);
Dictionary<Guid, Annotation> annotations = null;
// Now, get the annotations in the map that satisfies the query criterion
if (anchorLocator == null)
{
annotations = _storeAnnotationsMap.FindAnnotations();
}
else
{
annotations = _storeAnnotationsMap.FindAnnotations(anchorLocator);
}
// merge both query results
return MergeAndCacheAnnotations(annotations, annotationIds);
}
}
/// <summary>
/// Loads the current stream into the XmlDocument used by this
/// store as a backing store. If the stream doesn't contain any
/// data we load up a default XmlDocument for the Annotations schema.
/// The "http://schemas.microsoft.com/windows/annotations/2003/11/core"
/// namespace is registered with "anc" prefix and the
/// "http://schemas.microsoft.com/windows/annotations/2003/11/base" namespace
/// is registered with "anb" prefix as global namespaces.
/// We also select from the newly loaded document the new top
/// level node. This is used later for insertions, etc.
/// </summary>
/// <exception cref="XmlException">if the stream contains invalid XML</exception>
private void LoadStream(IDictionary<Uri, IList<Uri>> knownNamespaces)
{
//check input data first
CheckKnownNamespaces(knownNamespaces);
lock (SyncRoot)
{
_document = new XmlDocument();
_document.PreserveWhitespace = false;
if (_stream.Length == 0)
{
_document.LoadXml(
$"<?xml version=\"1.0\" encoding=\"utf-8\"?> <{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:Annotations xmlns:{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}=\"{AnnotationXmlConstants.Namespaces.CoreSchemaNamespace}\" xmlns:{AnnotationXmlConstants.Prefixes.BaseSchemaPrefix}=\"{AnnotationXmlConstants.Namespaces.BaseSchemaNamespace}\" />");
}
else
{
_xmlCompatibilityReader = SetupReader(knownNamespaces);
_document.Load(_xmlCompatibilityReader);
}
_namespaceManager = new XmlNamespaceManager(_document.NameTable);
_namespaceManager.AddNamespace(AnnotationXmlConstants.Prefixes.CoreSchemaPrefix, AnnotationXmlConstants.Namespaces.CoreSchemaNamespace);
_namespaceManager.AddNamespace(AnnotationXmlConstants.Prefixes.BaseSchemaPrefix, AnnotationXmlConstants.Namespaces.BaseSchemaNamespace);
// This use of an iterator is necessary because SelectSingleNode isn't available in the PD3
// drop of the CLR. Eventually we should be able to call SelectSingleNode and not have to
// use an iterator to get a single node.
XPathNavigator navigator = _document.CreateNavigator();
XPathNodeIterator iterator = navigator.Select($"//{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:Annotations", _namespaceManager);
Invariant.Assert(iterator.Count == 1, "More than one annotation returned for the query");
iterator.MoveNext();
_rootNavigator = (XPathNavigator)iterator.Current;
}
}
/// <summary>
/// Checks if passed external known namespaces are valid
/// </summary>
/// <param name="knownNamespaces">namespaces dictionary</param>
/// <remarks>We do not allow internal namespases in this dictionary nor
/// duplicates</remarks>
private void CheckKnownNamespaces(IDictionary<Uri, IList<Uri>> knownNamespaces)
{
if (knownNamespaces == null)
return;
IList<Uri> allNamespaces = new List<Uri>();
//add AnnotationFramework namespaces
foreach (Uri name in _predefinedNamespaces.Keys)
{
allNamespaces.Add(name);
}
//add external namespaces
foreach (Uri knownNamespace in knownNamespaces.Keys)
{
if (knownNamespace == null)
{
throw new ArgumentException(SR.NullUri, "knownNamespaces");
}
if (allNamespaces.Contains(knownNamespace))
{
throw new ArgumentException(SR.DuplicatedUri, "knownNamespaces");
}
allNamespaces.Add(knownNamespace);
}
// check compatible namespaces
foreach (KeyValuePair<Uri, IList<Uri>> item in knownNamespaces)
{
if (item.Value != null)
{
foreach (Uri name in item.Value)
{
if (name == null)
{
throw new ArgumentException(SR.NullUri, "knownNamespaces");
}
if (allNamespaces.Contains(name))
{
throw new ArgumentException(SR.DuplicatedCompatibleUri, "knownNamespaces");
}
allNamespaces.Add(name);
}//foreach
}//if
}//foreach
}
/// <summary>
/// Creates and initializes the XmlCompatibilityReader
/// </summary>
/// <param name="knownNamespaces">Dictionary of external known namespaces</param>
/// <returns>The XmlCompatibilityReader</returns>
private XmlCompatibilityReader SetupReader(IDictionary<Uri, IList<Uri>> knownNamespaces)
{
IList<string> supportedNamespaces = new List<string>();
//add AnnotationFramework namespaces
foreach (Uri name in _predefinedNamespaces.Keys)
{
supportedNamespaces.Add(name.ToString());
}
//add external namespaces
if (knownNamespaces != null)
{
foreach (Uri knownNamespace in knownNamespaces.Keys)
{
Debug.Assert(knownNamespace != null, "null knownNamespace");
supportedNamespaces.Add(knownNamespace.ToString());
}
}
//create XmlCompatibilityReader first
XmlCompatibilityReader reader = new XmlCompatibilityReader(new XmlTextReader(_stream),
new IsXmlNamespaceSupportedCallback(IsXmlNamespaceSupported), supportedNamespaces);
// Declare compatibility.
// Skip the Framework ones because they are all null in this version
if (knownNamespaces != null)
{
foreach (KeyValuePair<Uri, IList<Uri>> item in knownNamespaces)
{
if (item.Value != null)
{
foreach (Uri name in item.Value)
{
Debug.Assert(name != null, "null compatible namespace");
reader.DeclareNamespaceCompatibility(item.Key.ToString(), name.ToString());
}//foreach
}//if
}//foreach
}//if
//cleanup the _ignoredNamespaces
_ignoredNamespaces.Clear();
return reader;
}
/// <summary>
/// A callback for XmlCompatibilityReader
/// </summary>
/// <param name="xmlNamespace">inquired namespace</param>
/// <param name="newXmlNamespace">the newer subsumming namespace</param>
/// <returns>true if the namespace is known, false if not</returns>
/// <remarks>This API always returns false because all known namespaces are registered
/// before loading the Xml. It stores the namespace as ignored.</remarks>
private bool IsXmlNamespaceSupported(string xmlNamespace, out string newXmlNamespace)
{
//store the namespace if needed
if (!String.IsNullOrEmpty(xmlNamespace))
{
if (!Uri.IsWellFormedUriString(xmlNamespace, UriKind.RelativeOrAbsolute))
{
throw new ArgumentException(SR.Format(SR.InvalidNamespace, xmlNamespace), "xmlNamespace");
}
Uri namespaceUri = new Uri(xmlNamespace, UriKind.RelativeOrAbsolute);
if (!_ignoredNamespaces.Contains(namespaceUri))
_ignoredNamespaces.Add(namespaceUri);
}
newXmlNamespace = null;
return false;
}
/// <summary>
/// Selects the annotation XmlElement from the current document
/// with the given id.
/// </summary>
/// <param name="id">the id to query for in the XmlDocument</param>
/// <returns>the XmlElement representing the annotation with the given id</returns>
private XPathNavigator GetAnnotationNodeForId(Guid id)
{
XPathNavigator navigator = null;
lock (SyncRoot)
{
XPathNavigator tempNavigator = _document.CreateNavigator();
// This use of an iterator is necessary because SelectSingleNode isn't available in the PD3
// drop of the CLR. Eventually we should be able to call SelectSingleNode and not have to
// use an iterator to get a single node.
// We use XmlConvert.ToString to turn the Guid into a string because
// that's what is used by the Annotation's serialization methods.
XPathNodeIterator iterator = tempNavigator.Select($@"//{AnnotationXmlConstants.Prefixes.CoreSchemaPrefix}:Annotation[@Id=""{XmlConvert.ToString(id)}""]", _namespaceManager);
if (iterator.MoveNext())
{
navigator = (XPathNavigator)iterator.Current;
}
}
return navigator;
}
/// <summary>
/// Verifies the store is in a valid state. Throws exceptions otherwise.
/// </summary>
private void CheckStatus()
{
lock (SyncRoot)
{
if (IsDisposed)
throw new ObjectDisposedException(null, SR.ObjectDisposed_StoreClosed);
if (_stream == null)
throw new InvalidOperationException(SR.StreamNotSet);
}
}
/// <summary>
/// Called from flush to serialize all annotations in the map
/// notice that delete takes care of the delete action both in the map
/// and in the store
/// </summary>
private void SerializeAnnotations()
{
List<Annotation> mapAnnotations = _storeAnnotationsMap.FindDirtyAnnotations();
foreach (Annotation annotation in mapAnnotations)
{
XPathNavigator editor = GetAnnotationNodeForId(annotation.Id);
if (editor == null)
{
editor = (XPathNavigator)_rootNavigator.CreateNavigator();
XmlWriter writer = editor.AppendChild();
_serializer.Serialize(writer, annotation);
writer.Close();
}
else
{
XmlWriter writer = editor.InsertBefore();
_serializer.Serialize(writer, annotation);
writer.Close();
editor.DeleteSelf();
}
}
_storeAnnotationsMap.ValidateDirtyAnnotations();
}
/// <summary>
/// Discards changes and cleans up references.
/// </summary>
private void Cleanup()
{
lock (SyncRoot)
{
_xmlCompatibilityReader = null;
_ignoredNamespaces = null;
_stream = null;
_document = null;
_rootNavigator = null;
_storeAnnotationsMap = null;
}
}
/// <summary>
/// Sets the stream for this store. Assumes Cleanup has
/// been previously called (or this is a new store).
/// </summary>
/// <param name="stream">new stream for this store</param>
/// <param name="knownNamespaces">List of known and compatible namespaces used to initialize
/// the XmlCompatibilityReader</param>
private void SetStream(Stream stream, IDictionary<Uri, IList<Uri>> knownNamespaces)
{
try
{
lock (SyncRoot)
{
_storeAnnotationsMap = new StoreAnnotationsMap(HandleAuthorChanged, HandleAnchorChanged, HandleCargoChanged);
_stream = stream;
LoadStream(knownNamespaces);
}
}
catch
{
Cleanup();
throw;
}
}
#endregion Private Methods
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
// Dirty bit for the store's in-memory cache
private bool _dirty;
// Boolean flag represents whether the store should perform a flush
// after every operation or not
private bool _autoFlush;
// XmlDocument used as an in-memory cache of the stream's XML content
private XmlDocument _document;
// Namespace manager used for all queries.
private XmlNamespaceManager _namespaceManager;
// Stream passed in by the creator of this instance.
private Stream _stream;
// The xpath navigator used to navigate the annotations Xml stream
private XPathNavigator _rootNavigator;
// map that holds AnnotationId->Annotation
StoreAnnotationsMap _storeAnnotationsMap;
//list of ignored namespaces during XmlLoad
List<Uri> _ignoredNamespaces = new List<Uri>();
//XmlCompatibilityReader - we need to hold that one open, so the underlying stream stays open too
// if the store is disposed the reader will be disposed and the stream will be closed too.
XmlCompatibilityReader _xmlCompatibilityReader;
///
///Static fields
///
//predefined namespaces
private static readonly Dictionary<Uri, IList<Uri>> _predefinedNamespaces;
// Serializer for Annotations
private static readonly Serializer _serializer = new Serializer(typeof(Annotation));
#endregion Private Fields
}
}
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