Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Xml/System/Xml/BinHexDecoder.cs

@@ -0,0 +1,212 @@
+//------------------------------------------------------------------------------
+// <copyright file="BinHexDecoder.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+using System;
+using System.Diagnostics;
+
+namespace System.Xml
+{
+    internal class BinHexDecoder : IncrementalReadDecoder {
+//
+// Fields
+//
+        byte[]  buffer;
+        int     startIndex;
+        int     curIndex;
+        int     endIndex;
+        bool    hasHalfByteCached;
+        byte    cachedHalfByte;
+
+//
+// IncrementalReadDecoder interface
+//
+        internal override int DecodedCount { 
+            get { 
+                return curIndex - startIndex; 
+            } 
+        }
+
+        internal override bool IsFull { 
+            get { 
+                return curIndex == endIndex; 
+            }
+        }
+
+#if SILVERLIGHT && !SILVERLIGHT_DISABLE_SECURITY
+        [System.Security.SecuritySafeCritical]
+#endif
+        internal override unsafe int Decode(char[] chars, int startPos, int len) {
+            if ( chars == null ) {
+                throw new ArgumentNullException( "chars" );
+            }
+            if ( len < 0 ) {
+                throw new ArgumentOutOfRangeException( "len" );
+            }
+            if ( startPos < 0 ) {
+                throw new ArgumentOutOfRangeException( "startPos" );
+            }
+            if ( chars.Length - startPos < len ) {
+                throw new ArgumentOutOfRangeException( "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 ),  
+                            ref this.hasHalfByteCached, ref this.cachedHalfByte, out charsDecoded, out bytesDecoded );
+                }
+            }
+            curIndex += bytesDecoded;
+            return charsDecoded;
+        }
+
+#if SILVERLIGHT && !SILVERLIGHT_DISABLE_SECURITY
+        [System.Security.SecuritySafeCritical]
+#endif
+        internal override unsafe int Decode(string str, int startPos, int len) {
+            if ( str == null ) {
+                throw new ArgumentNullException( "str" );
+            }
+            if ( len < 0 ) {
+                throw new ArgumentOutOfRangeException( "len" );
+            }
+            if ( startPos < 0 ) {
+                throw new ArgumentOutOfRangeException( "startPos" );
+            }
+            if ( str.Length - startPos < len ) {
+                throw new ArgumentOutOfRangeException( "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 ),  
+                            ref this.hasHalfByteCached, ref this.cachedHalfByte, out charsDecoded, out bytesDecoded );
+                }
+            }
+            curIndex += bytesDecoded;
+            return charsDecoded;
+        }
+
+        internal override void Reset() {
+            this.hasHalfByteCached = false;
+            this.cachedHalfByte = 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;
+        }
+
+//
+// Static methods
+//
+#if SILVERLIGHT && !SILVERLIGHT_DISABLE_SECURITY
+        [System.Security.SecuritySafeCritical]
+#endif
+        public static unsafe byte[] Decode(char[] chars, bool allowOddChars) {
+            if ( chars == null ) {
+                throw new ArgumentNullException( "chars" );
+            }
+            
+            int len = chars.Length;
+            if ( len == 0 ) {
+                return new byte[0];
+            }
+
+            byte[] bytes = new byte[ ( len + 1 ) / 2 ];
+            int bytesDecoded, charsDecoded;
+            bool hasHalfByteCached = false;
+            byte cachedHalfByte = 0;
+            
+            fixed ( char* pChars = &chars[0] ) {
+                fixed ( byte* pBytes = &bytes[0] ) {
+                    Decode( pChars, pChars + len, pBytes, pBytes + bytes.Length, ref hasHalfByteCached, ref cachedHalfByte, out charsDecoded, out bytesDecoded );
+                }
+            }
+
+            if ( hasHalfByteCached && !allowOddChars ) {
+                throw new XmlException( Res.Xml_InvalidBinHexValueOddCount, new string( chars ) );
+            }
+
+            if ( bytesDecoded < bytes.Length ) {
+                byte[] tmp = new byte[ bytesDecoded ];
+                Array.Copy( bytes, 0, tmp, 0, bytesDecoded );
+                bytes = tmp;
+            }
+
+            return bytes;
+        }
+
+//
+// Private methods
+//
+
+#if SILVERLIGHT && !SILVERLIGHT_DISABLE_SECURITY
+        [System.Security.SecurityCritical]
+#endif
+        private static unsafe void Decode(char* pChars, char* pCharsEndPos, 
+                                    byte* pBytes, byte* pBytesEndPos, 
+                                    ref bool hasHalfByteCached, ref byte cachedHalfByte,
+								    out int charsDecoded, out int bytesDecoded ) {
+#if DEBUG
+            Debug.Assert( pCharsEndPos - pChars >= 0 );
+            Debug.Assert( pBytesEndPos - pBytes >= 0 );
+#endif
+
+            char* pChar = pChars;
+            byte* pByte = pBytes;
+            XmlCharType xmlCharType = XmlCharType.Instance;
+            while ( pChar < pCharsEndPos && pByte < pBytesEndPos ) {
+                byte halfByte;
+                char ch = *pChar++;
+
+                if ( ch >= 'a' && ch <= 'f' ) {
+                    halfByte = (byte)(ch - 'a' + 10);
+                }
+                else if ( ch >= 'A' && ch <= 'F' ) {
+                    halfByte = (byte)(ch - 'A' + 10);
+                }
+                else if ( ch >= '0' && ch <= '9' ) {
+                    halfByte = (byte)(ch - '0');
+                }
+                else if ( ( xmlCharType.charProperties[ch] & XmlCharType.fWhitespace ) != 0 ) { // else if ( xmlCharType.IsWhiteSpace( ch ) ) {
+                    continue; 
+                }
+                else {
+                    throw new XmlException( Res.Xml_InvalidBinHexValue, new string( pChars, 0, (int)( pCharsEndPos - pChars ) ) );
+                }
+
+                if ( hasHalfByteCached ) {
+                    *pByte++ = (byte)( ( cachedHalfByte << 4 ) + halfByte );
+                    hasHalfByteCached = false;
+                }
+                else {
+                    cachedHalfByte = halfByte;
+                    hasHalfByteCached = true;
+                }
+            }
+
+            bytesDecoded = (int)(pByte - pBytes);
+            charsDecoded = (int)(pChar - pChars);
+        }
+    }
+}