Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,179 @@
+//------------------------------------------------------------------------------
+// <copyright file="XmlComplianceUtil.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+//------------------------------------------------------------------------------
+
+using System;
+using System.IO;
+
+namespace System.Xml {
+    using System.Text;
+
+    internal static class XmlComplianceUtil {
+
+        // Replaces \r\n, \n, \r and \t with single space (0x20) and then removes spaces
+        // at the beggining and and the end of the string and replaces sequences of spaces
+        // with a single space.
+        public static string NonCDataNormalize( string value ) {
+            int len = value.Length;
+            if ( len <= 0 ) {
+               return string.Empty;
+            }
+
+            int startPos = 0;
+            StringBuilder norValue = null;
+            XmlCharType xmlCharType = XmlCharType.Instance;
+            while ( xmlCharType.IsWhiteSpace( value[startPos] ) ) {
+                startPos++;
+                if ( startPos == len ) {
+                    return " ";
+                }
+            }
+
+            int i = startPos;
+            while ( i < len ) {
+                if ( !xmlCharType.IsWhiteSpace( value[i] ) ) {
+                    i++;
+                    continue;
+                }
+
+                int j = i + 1;
+                while ( j < len && xmlCharType.IsWhiteSpace( value[j] ) ) {
+                    j++;
+                }
+                if ( j == len ) {
+                    if ( norValue == null ) {
+                        return value.Substring( startPos, i - startPos );
+                    }
+                    else {
+                        norValue.Append( value, startPos, i - startPos );
+                        return norValue.ToString();
+                    }
+                }
+                if (j > i + 1 || value[i] != 0x20 ) {
+                    if ( norValue == null ) {
+                        norValue = new StringBuilder( len );
+                    }
+                    norValue.Append( value, startPos, i - startPos );
+                    norValue.Append( (char)0x20 );
+                    startPos = j;
+                    i = j;
+                }
+                else {
+                    i++;
+                }
+            }
+
+            if ( norValue != null ) {
+                if ( startPos < i ) {
+                    norValue.Append( value, startPos, i - startPos );
+                }
+                return norValue.ToString();
+            }
+            else {
+                if ( startPos > 0 ) {
+                    return value.Substring( startPos, len - startPos );
+                }
+                else {
+                    return value;
+                }
+            }
+        }
+
+        // Replaces \r\n, \n, \r and \t with single space (0x20) 
+        public static string CDataNormalize( string value ) {
+            int len = value.Length;
+
+            if ( len <= 0 ) {
+               return string.Empty;
+            }
+
+            int i = 0;
+            int startPos = 0;
+            StringBuilder norValue = null;
+
+            while ( i < len ) {
+                char ch = value[i];
+                if ( ch >= 0x20 || ( ch != 0x9 && ch != 0xA && ch != 0xD ) ) {
+                    i++;
+                    continue;
+                }
+
+                if ( norValue == null ) {
+                    norValue = new StringBuilder( len );
+                }
+                if ( startPos < i ) {
+                    norValue.Append( value, startPos, i - startPos );
+                }
+                norValue.Append( (char)0x20 );
+
+                if ( ch == 0xD && ( i+1 < len && value[i+1] == 0xA ) ) {
+                    i += 2;
+                }
+                else {
+                    i++;
+                }
+                startPos = i;
+            }
+
+            if ( norValue == null ) {
+                return value;
+            }
+            else {
+               if ( i > startPos ) {
+                   norValue.Append(value, startPos, i-startPos);
+               }
+               return norValue.ToString();
+            }
+        }
+
+        public static bool IsValidLanguageID( char[] value, int startPos, int length ) {
+            int len = length;
+            if ( len < 2 ) {
+                return false;
+            }
+
+            bool fSeenLetter = false;
+            int i = startPos;
+            XmlCharType xmlCharType = XmlCharType.Instance;
+
+            char ch = value[i];
+            if ( xmlCharType.IsLetter(ch) ) {
+                if ( xmlCharType.IsLetter( value[++i] ) ) {
+                    if ( len == 2 ) {
+                        return true;
+                    }
+                    len--;
+                    i++;
+                }
+                else if ( ('I' != ch && 'i' != ch ) && ( 'X' != ch && 'x' != ch ) ) {  //IANA or custom Code
+                    return false;
+                }
+
+                if ( value[i] != '-' ) {
+                    return false;
+                }
+
+                len -= 2;
+                while ( len-- > 0 ) {
+                    ch = value[++i];
+                    if ( xmlCharType.IsLetter( ch ) ) {
+                        fSeenLetter = true;
+                    }
+                    else if ( ch == '-' && fSeenLetter ) {
+                        fSeenLetter = false;
+                    }
+                    else {
+                        return false;
+                    }
+                }
+                if ( fSeenLetter ) {
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
+}