internal static XNamespace Get(string namespaceName, int index, int count)
{
XNamespace namespace2;
if (count == 0)
{
return(None);
}
if (namespaces == null)
{
Interlocked.CompareExchange <XHashtable <WeakReference> >(ref namespaces, new XHashtable <WeakReference>(new XHashtable <WeakReference> .ExtractKeyDelegate(XNamespace.ExtractNamespace), 0x20), null);
}
do
{
WeakReference reference;
if (!namespaces.TryGetValue(namespaceName, index, count, out reference))
{
if ((count == "http://www.w3.org/XML/1998/namespace".Length) && (string.CompareOrdinal(namespaceName, index, "http://www.w3.org/XML/1998/namespace", 0, count) == 0))
{
return(Xml);
}
if ((count == "http://www.w3.org/2000/xmlns/".Length) && (string.CompareOrdinal(namespaceName, index, "http://www.w3.org/2000/xmlns/", 0, count) == 0))
{
return(Xmlns);
}
reference = namespaces.Add(new WeakReference(new XNamespace(namespaceName.Substring(index, count))));
}
namespace2 = (reference != null) ? ((XNamespace)reference.Target) : null;
}while (namespace2 == null);
return(namespace2);
}
/// <summary>
/// Returns an <see cref="XName"/> created from this XNamespace <see cref="XName"/> and a portion of the passed in
/// local name parameter. The returned <see cref="XName"/> object is guaranteed to be atomic (i.e. the only one in the system for
/// this particular expanded name).
/// </summary>
internal XName GetName(string localName, int index, int count)
{
Debug.Assert(index >= 0 && index <= localName.Length, "Caller should have checked that index was in bounds");
Debug.Assert(count >= 0 && index + count <= localName.Length, "Caller should have checked that count was in bounds");
// Attempt to get the local name from the hash table
XName?name;
if (_names.TryGetValue(localName, index, count, out name))
{
return(name);
}
// No local name has yet been added, so add it now
return(_names.Add(new XName(this, localName.Substring(index, count))));
}
/// <summary>
/// Returns an <see cref="XNamespace"/> created from a portion of the passed in namespace name parameter. The returned <see cref="XNamespace"/>
/// object is guaranteed to be atomic (i.e. the only one in the system for this particular namespace name).
/// </summary>
internal static XNamespace Get(string namespaceName, int index, int count)
{
Debug.Assert(index >= 0 && index <= namespaceName.Length, "Caller should have checked that index was in bounds");
Debug.Assert(count >= 0 && index + count <= namespaceName.Length, "Caller should have checked that count was in bounds");
if (count == 0)
{
return(None);
}
// Use CompareExchange to ensure that exactly one XHashtable<WeakReference> is used to store namespaces
if (s_namespaces == null)
{
Interlocked.CompareExchange(ref s_namespaces, new XHashtable <WeakReference <XNamespace> >(ExtractNamespace, NamespacesCapacity), null);
}
WeakReference <XNamespace>?refNamespace;
XNamespace?ns;
// Keep looping until a non-null namespace has been retrieved
do
{
// Attempt to get the WeakReference for the namespace from the hash table
if (!s_namespaces.TryGetValue(namespaceName, index, count, out refNamespace))
{
// If it is not there, first determine whether it's a special namespace
if (count == xmlPrefixNamespace.Length && string.CompareOrdinal(namespaceName, index, xmlPrefixNamespace, 0, count) == 0)
{
return(Xml);
}
if (count == xmlnsPrefixNamespace.Length && string.CompareOrdinal(namespaceName, index, xmlnsPrefixNamespace, 0, count) == 0)
{
return(Xmlns);
}
// Go ahead and create the namespace and add it to the table
refNamespace = s_namespaces.Add(new WeakReference <XNamespace>(new XNamespace(namespaceName.Substring(index, count))));
}
ns = refNamespace != null && refNamespace.TryGetTarget(out XNamespace? target) ? target : null;
}while (ns == null);
return(ns);
}