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//------------------------------------------------------------------------------
// <copyright file="XmlNamespaceManager.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Xml {
using System;
using System.IO;
using System.Collections;
using System.Diagnostics;
using System.Collections.Generic;
public class XmlNamespaceManager : IXmlNamespaceResolver, IEnumerable {
#if !SILVERLIGHT // EmptyResolver is not used in Silverlight
static volatile IXmlNamespaceResolver s_EmptyResolver;
#endif
struct NamespaceDeclaration {
public string prefix;
public string uri;
public int scopeId;
public int previousNsIndex;
public void Set( string prefix, string uri, int scopeId, int previousNsIndex ) {
this.prefix = prefix;
this.uri = uri;
this.scopeId = scopeId;
this.previousNsIndex = previousNsIndex;
}
}
// array with namespace declarations
NamespaceDeclaration[] nsdecls;
// index of last declaration
int lastDecl = 0;
// name table
XmlNameTable nameTable;
// ID (depth) of the current scope
int scopeId;
// hash table for faster lookup when there is lots of namespaces
Dictionary<string,int> hashTable;
bool useHashtable;
// atomized prefixes for "xml" and "xmlns"
string xml;
string xmlNs;
// Constants
const int MinDeclsCountForHashtable = 16;
#if !SILVERLIGHT // EmptyResolver is not used in Silverlight
internal static IXmlNamespaceResolver EmptyResolver {
get {
if ( s_EmptyResolver == null ) {
// no locking; the empty resolver is immutable so it's not a problem that it may get initialized more than once
s_EmptyResolver = new XmlNamespaceManager( new NameTable() );
}
return s_EmptyResolver;
}
}
#endif
#if !SILVERLIGHT // This constructor is not used in Silverlight
internal XmlNamespaceManager() {
}
#endif
public XmlNamespaceManager( XmlNameTable nameTable ) {
this.nameTable = nameTable;
xml = nameTable.Add("xml");
xmlNs = nameTable.Add("xmlns");
nsdecls = new NamespaceDeclaration[8];
string emptyStr = nameTable.Add( string.Empty );
nsdecls[0].Set( emptyStr, emptyStr, -1, -1 );
nsdecls[1].Set( xmlNs, nameTable.Add( XmlReservedNs.NsXmlNs ), -1, -1 );
nsdecls[2].Set( xml, nameTable.Add( XmlReservedNs.NsXml ), 0, -1 );
lastDecl = 2;
scopeId = 1;
}
public virtual XmlNameTable NameTable {
get {
return nameTable;
}
}
public virtual string DefaultNamespace {
get {
string defaultNs = LookupNamespace( string.Empty );
return ( defaultNs == null ) ? string.Empty : defaultNs;
}
}
public virtual void PushScope() {
scopeId++;
}
public virtual bool PopScope() {
int decl = lastDecl;
if ( scopeId == 1 ) {
return false;
}
while( nsdecls[decl].scopeId == scopeId ) {
if ( useHashtable ) {
hashTable[nsdecls[decl].prefix] = nsdecls[decl].previousNsIndex;
}
decl--;
Debug.Assert( decl >= 2 );
}
lastDecl = decl;
scopeId--;
return true;
}
public virtual void AddNamespace( string prefix, string uri ) {
if ( uri == null )
throw new ArgumentNullException( "uri" );
if ( prefix == null )
throw new ArgumentNullException( "prefix" );
prefix = nameTable.Add( prefix );
uri = nameTable.Add( uri );
if ( ( Ref.Equal( xml, prefix ) && !uri.Equals( XmlReservedNs.NsXml ) ) ) {
throw new ArgumentException( Res.GetString( Res.Xml_XmlPrefix ) );
}
if ( Ref.Equal( xmlNs, prefix ) ) {
throw new ArgumentException( Res.GetString( Res.Xml_XmlnsPrefix ) );
}
int declIndex = LookupNamespaceDecl( prefix );
int previousDeclIndex = -1;
if ( declIndex != -1 ) {
if ( nsdecls[declIndex].scopeId == scopeId ) {
// redefine if in the same scope
nsdecls[declIndex].uri = uri;
return;
}
else {
// othewise link
previousDeclIndex = declIndex;
}
}
// set new namespace declaration
if ( lastDecl == nsdecls.Length - 1 ) {
NamespaceDeclaration[] newNsdecls = new NamespaceDeclaration[nsdecls.Length * 2];
Array.Copy( nsdecls, 0, newNsdecls, 0, nsdecls.Length );
nsdecls = newNsdecls;
}
nsdecls[++lastDecl].Set( prefix, uri, scopeId, previousDeclIndex );
// add to hashTable
if ( useHashtable ) {
hashTable[prefix] = lastDecl;
}
// or create a new hashTable if the threashold has been reached
else if ( lastDecl >= MinDeclsCountForHashtable ) {
// add all to hash table
Debug.Assert( hashTable == null );
hashTable = new Dictionary<string,int>( lastDecl );
for ( int i = 0; i <= lastDecl; i++ ) {
hashTable[nsdecls[i].prefix] = i;
}
useHashtable = true;
}
}
public virtual void RemoveNamespace( string prefix, string uri ) {
if ( uri == null ) {
throw new ArgumentNullException( "uri" );
}
if ( prefix == null ) {
throw new ArgumentNullException( "prefix" );
}
int declIndex = LookupNamespaceDecl( prefix );
while ( declIndex != -1 ) {
if ( String.Equals( nsdecls[declIndex].uri, uri ) && nsdecls[declIndex].scopeId == scopeId ) {
nsdecls[declIndex].uri = null;
}
declIndex = nsdecls[declIndex].previousNsIndex;
}
}
public virtual IEnumerator GetEnumerator() {
Dictionary<string, string> prefixes = new Dictionary<string, string>(lastDecl + 1);
for( int thisDecl = 0; thisDecl <= lastDecl; thisDecl ++ ) {
if ( nsdecls[thisDecl].uri != null ) {
prefixes[nsdecls[thisDecl].prefix] = nsdecls[thisDecl].prefix;
}
}
return prefixes.Keys.GetEnumerator();
}
// This pragma disables a warning that the return type is not CLS-compliant, but generics are part of CLS in Whidbey.
#pragma warning disable 3002
public virtual IDictionary<string,string> GetNamespacesInScope( XmlNamespaceScope scope ) {
#pragma warning restore 3002
int i = 0;
switch ( scope ) {
case XmlNamespaceScope.All:
i = 2;
break;
case XmlNamespaceScope.ExcludeXml:
i = 3;
break;
case XmlNamespaceScope.Local:
i = lastDecl;
while ( nsdecls[i].scopeId == scopeId ) {
i--;
Debug.Assert( i >= 2 );
}
i++;
break;
}
Dictionary<string,string> dict = new Dictionary<string, string>( lastDecl - i + 1 );
for( ; i <= lastDecl; i++ ) {
string prefix = nsdecls[i].prefix;
string uri = nsdecls[i].uri;
Debug.Assert( prefix != null );
if ( uri != null ) {
if ( uri.Length > 0 || prefix.Length > 0 || scope == XmlNamespaceScope.Local ) {
dict[prefix] = uri;
}
else {
// default namespace redeclared to "" -> remove from list for all scopes other than local
dict.Remove( prefix );
}
}
}
return dict;
}
public virtual string LookupNamespace( string prefix ) {
int declIndex = LookupNamespaceDecl( prefix );
return ( declIndex == -1 ) ? null : nsdecls[declIndex].uri;
}
private int LookupNamespaceDecl( string prefix ) {
if ( useHashtable ) {
int declIndex;
if ( hashTable.TryGetValue( prefix, out declIndex ) ) {
while ( declIndex != -1 && nsdecls[declIndex].uri == null ) {
declIndex = nsdecls[declIndex].previousNsIndex;
}
return declIndex;
}
return -1;
}
else {
// First assume that prefix is atomized
for( int thisDecl = lastDecl; thisDecl >= 0; thisDecl -- ) {
if ( (object)nsdecls[thisDecl].prefix == (object)prefix && nsdecls[thisDecl].uri != null ) {
return thisDecl;
}
}
// Non-atomized lookup
for( int thisDecl = lastDecl; thisDecl >= 0; thisDecl -- ) {
if ( String.Equals( nsdecls[thisDecl].prefix, prefix ) && nsdecls[thisDecl].uri != null ) {
return thisDecl;
}
}
}
return -1;
}
public virtual string LookupPrefix( string uri ) {
// Don't assume that prefix is atomized
for( int thisDecl = lastDecl; thisDecl >= 0; thisDecl -- ) {
if ( String.Equals( nsdecls[thisDecl].uri, uri ) ) {
string prefix = nsdecls[thisDecl].prefix;
if ( String.Equals( LookupNamespace( prefix ), uri ) ) {
return prefix;
}
}
}
return null;
}
public virtual bool HasNamespace( string prefix ) {
// Don't assume that prefix is atomized
for( int thisDecl = lastDecl; nsdecls[thisDecl].scopeId == scopeId; thisDecl-- ) {
if ( String.Equals( nsdecls[thisDecl].prefix, prefix ) && nsdecls[thisDecl].uri != null ) {
if ( prefix.Length > 0 || nsdecls[thisDecl].uri.Length > 0 ) {
return true;
}
return false;
}
}
return false;
}
#if !SILVERLIGHT // This method is not used in Silverlight
internal bool GetNamespaceDeclaration( int idx, out string prefix, out string uri ) {
idx = lastDecl - idx;
if ( idx < 0 ) {
prefix = uri = null;
return false;
}
prefix = nsdecls[idx].prefix;
uri = nsdecls[idx].uri;
return true;
}
#endif
} //XmlNamespaceManager
}
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