Code:
/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / Xml / System / Xml / Base64Decoder.cs / 1 / Base64Decoder.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //----------------------------------------------------------------------------- using System; using System.Diagnostics; namespace System.Xml { internal class Base64Decoder : IncrementalReadDecoder { // // Fields // byte[] buffer; int startIndex; int curIndex; int endIndex; int bits; int bitsFilled; private static readonly String CharsBase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; private static readonly byte[] MapBase64 = ConstructMapBase64(); private const int MaxValidChar = (int)'z'; private const byte Invalid = unchecked((byte)-1); // // IncrementalReadDecoder interface // internal override int DecodedCount { get { return curIndex - startIndex; } } internal override bool IsFull { get { return curIndex == endIndex; } } internal override unsafe int Decode( char[] chars, int startPos, int len ) { Debug.Assert( chars != null ); Debug.Assert( len >= 0 ); Debug.Assert( startPos >= 0 ); Debug.Assert( chars.Length - startPos >= len ); if ( len == 0 ) { return 0; } int bytesDecoded, charsDecoded; fixed ( char* pChars = &chars[startPos] ) { fixed ( byte* pBytes = &buffer[curIndex] ) { Decode( pChars, pChars + len, pBytes, pBytes + ( endIndex - curIndex ), out charsDecoded, out bytesDecoded ); } } curIndex += bytesDecoded; return charsDecoded; } internal override unsafe int Decode( string str, int startPos, int len ) { Debug.Assert( str != null ); Debug.Assert( len >= 0 ); Debug.Assert( startPos >= 0 ); Debug.Assert( str.Length - startPos >= len ); if ( len == 0 ) { return 0; } int bytesDecoded, charsDecoded; fixed ( char* pChars = str ) { fixed ( byte* pBytes = &buffer[curIndex] ) { Decode( pChars + startPos, pChars + startPos + len, pBytes, pBytes + ( endIndex - curIndex ), out charsDecoded, out bytesDecoded ); } } curIndex += bytesDecoded; return charsDecoded; } internal override void Reset() { bitsFilled = 0; bits = 0; } internal override void SetNextOutputBuffer( Array buffer, int index, int count ) { Debug.Assert( buffer != null ); Debug.Assert( count >= 0 ); Debug.Assert( index >= 0 ); Debug.Assert( buffer.Length - index >= count ); Debug.Assert( ( buffer as byte[] ) != null ); this.buffer = (byte[])buffer; this.startIndex = index; this.curIndex = index; this.endIndex = index + count; } // // Private methods // private static byte[] ConstructMapBase64() { byte[] mapBase64 = new byte[MaxValidChar + 1]; for ( int i = 0; i < mapBase64.Length; i++ ) { mapBase64[i]= Invalid; } for ( int i = 0; i < CharsBase64.Length; i++ ) { mapBase64[(int)CharsBase64[i]] = (byte)i; } return mapBase64; } private unsafe void Decode( char* pChars, char* pCharsEndPos, byte* pBytes, byte* pBytesEndPos, out int charsDecoded, out int bytesDecoded ) { #if DEBUG Debug.Assert( pCharsEndPos - pChars >= 0 ); Debug.Assert( pBytesEndPos - pBytes >= 0 ); #endif // walk hex digits pairing them up and shoving the value of each pair into a byte byte *pByte = pBytes; char *pChar = pChars; int b = bits; int bFilled = bitsFilled; XmlCharType xmlCharType = XmlCharType.Instance; while ( pChar < pCharsEndPos && pByte < pBytesEndPos ) { char ch = *pChar; // end? if ( ch == '=' ) { break; } pChar++; // ignore white space if ( ( xmlCharType.charProperties[ch] & XmlCharType.fWhitespace ) != 0 ) { // if ( xmlCharType.IsWhiteSpace(ch) ) { continue; } int digit; if ( ch > 122 || ( digit = MapBase64[ch] ) == Invalid ) { throw new XmlException(Res.Xml_InvalidBase64Value, new string( pChars, 0, (int)(pCharsEndPos - pChars) )); } b = ( b << 6 ) | digit; bFilled += 6; if ( bFilled >= 8 ) { // get top eight valid bits *pByte++ = (byte)( ( b >> ( bFilled - 8 ) ) & 0xFF ); bFilled -= 8; if ( pByte == pBytesEndPos ) { goto Return; } } } if ( pChar < pCharsEndPos && *pChar == '=' ) { bFilled = 0; // ignore padding chars do { pChar++; } while ( pChar < pCharsEndPos && *pChar == '=' ); // ignore whitespace after the padding chars if ( pChar < pCharsEndPos ) { do { if ( !( ( xmlCharType.charProperties[*pChar++] & XmlCharType.fWhitespace ) != 0 ) ) { // if ( !( xmlCharType.IsWhiteSpace( chars[charPos++] ) ) ) { throw new XmlException(Res.Xml_InvalidBase64Value, new string( pChars, 0, (int)( pCharsEndPos - pChars ) )); } } while ( pChar < pCharsEndPos ); } } Return: bits = b; bitsFilled = bFilled; bytesDecoded = (int)(pByte - pBytes); charsDecoded = (int)(pChar - pChars); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- EntityViewGenerationConstants.cs
- ActiveXContainer.cs
- DBSqlParserTable.cs
- BulletChrome.cs
- WebPartsPersonalization.cs
- smtppermission.cs
- EmptyReadOnlyDictionaryInternal.cs
- GenericArgumentsUpdater.cs
- ProfileSection.cs
- SqlFlattener.cs
- Base64Stream.cs
- SoapIgnoreAttribute.cs
- IntegerCollectionEditor.cs
- ButtonBase.cs
- SiteIdentityPermission.cs
- UnsafeNativeMethodsPenimc.cs
- DocumentPageTextView.cs
- UrlPath.cs
- PointCollectionConverter.cs
- ValueChangedEventManager.cs
- PersonalizationAdministration.cs
- NativeMethods.cs
- ComponentCodeDomSerializer.cs
- SparseMemoryStream.cs
- CategoryNameCollection.cs
- FormatStringEditor.cs
- WebPartConnectionsDisconnectVerb.cs
- StringConverter.cs
- DecoratedNameAttribute.cs
- HotSpotCollectionEditor.cs
- DataGridDefaultColumnWidthTypeConverter.cs
- SerializationObjectManager.cs
- WebBaseEventKeyComparer.cs
- ConnectionConsumerAttribute.cs
- FontStyleConverter.cs
- ByteRangeDownloader.cs
- ITextView.cs
- FileDialogCustomPlaces.cs
- DataGridItemEventArgs.cs
- SafePEFileHandle.cs
- Int32AnimationUsingKeyFrames.cs
- MemberAccessException.cs
- SwitchAttribute.cs
- Icon.cs
- DataTableMappingCollection.cs
- HttpEncoderUtility.cs
- BamlTreeUpdater.cs
- EncoderParameter.cs
- DataServiceStreamResponse.cs
- DrawingCollection.cs
- BigInt.cs
- MessageEventSubscriptionService.cs
- ExpressionVisitor.cs
- X509Extension.cs
- TypeInitializationException.cs
- PagerStyle.cs
- CodeArrayCreateExpression.cs
- HiddenFieldPageStatePersister.cs
- ValidatingReaderNodeData.cs
- FileRecordSequenceHelper.cs
- SemanticAnalyzer.cs
- ManualWorkflowSchedulerService.cs
- RegisteredHiddenField.cs
- UserNamePasswordServiceCredential.cs
- QilLiteral.cs
- FontUnitConverter.cs
- UnsafeNativeMethodsTablet.cs
- DefaultParameterValueAttribute.cs
- SafeRightsManagementPubHandle.cs
- ETagAttribute.cs
- DomNameTable.cs
- Material.cs
- DataGridViewRowStateChangedEventArgs.cs
- CheckBoxStandardAdapter.cs
- SafeFileMappingHandle.cs
- InputMethodStateChangeEventArgs.cs
- DocumentsTrace.cs
- VersionedStream.cs
- BinaryFormatterWriter.cs
- PathFigure.cs
- XmlSchemaSimpleContent.cs
- PropertyDescriptorCollection.cs
- PrivilegedConfigurationManager.cs
- DynamicPropertyReader.cs
- LayoutEditorPart.cs
- UnsignedPublishLicense.cs
- ProfilePropertySettingsCollection.cs
- ColumnWidthChangedEvent.cs
- AttributeData.cs
- TextSelectionHelper.cs
- SecurityRuntime.cs
- DoubleLinkList.cs
- WorkflowLayouts.cs
- SystemTcpConnection.cs
- ProxyFragment.cs
- FileNameEditor.cs
- ApplyHostConfigurationBehavior.cs
- MsmqAppDomainProtocolHandler.cs
- SqlClientMetaDataCollectionNames.cs
- SQLUtility.cs