Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Runtime.Serialization/System/Xml/XmlDictionaryString.cs

@@ -0,0 +1,142 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+namespace System.Xml
+{
+    using System;
+    using System.Xml;
+    using System.Text;
+    using System.Diagnostics;
+    using System.Runtime.Serialization;
+
+    public class XmlDictionaryString
+    {
+        internal const int MinKey = 0;
+        internal const int MaxKey = int.MaxValue / 4;
+
+        IXmlDictionary dictionary;
+        string value;
+        int key;
+        byte[] buffer;
+        static EmptyStringDictionary emptyStringDictionary = new EmptyStringDictionary();
+
+        public XmlDictionaryString(IXmlDictionary dictionary, string value, int key)
+        {
+            if (dictionary == null)
+                throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException("dictionary"));
+            if (value == null)
+                throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException("value"));
+            if (key < MinKey || key > MaxKey)
+                throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentOutOfRangeException("key", SR.GetString(SR.ValueMustBeInRange, MinKey, MaxKey)));
+            this.dictionary = dictionary;
+            this.value = value;
+            this.key = key;
+        }
+
+        static internal string GetString(XmlDictionaryString s)
+        {
+            if (s == null)
+                return null;
+            return s.Value;
+        }
+
+        static public XmlDictionaryString Empty
+        {
+            get
+            {
+                return emptyStringDictionary.EmptyString;
+            }
+        }
+
+        public IXmlDictionary Dictionary
+        {
+            get
+            {
+                return dictionary;
+            }
+        }
+
+        public int Key
+        {
+            get
+            {
+                return key;
+            }
+        }
+
+        public string Value
+        {
+            get
+            {
+                return value;
+            }
+        }
+
+        internal byte[] ToUTF8()
+        {
+            if (buffer == null)
+                buffer = System.Text.Encoding.UTF8.GetBytes(value);
+            return buffer;
+        }
+
+        public override string ToString()
+        {
+            return value;
+        }
+
+        class EmptyStringDictionary : IXmlDictionary
+        {
+            XmlDictionaryString empty;
+
+            public EmptyStringDictionary()
+            {
+                empty = new XmlDictionaryString(this, string.Empty, 0);
+            }
+
+            public XmlDictionaryString EmptyString
+            {
+                get
+                {
+                    return empty;
+                }
+            }
+
+            public bool TryLookup(string value, out XmlDictionaryString result)
+            {
+                if (value == null)
+                    throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("value");
+                if (value.Length == 0)
+                {
+                    result = empty;
+                    return true;
+                }
+                result = null;
+                return false;
+            }
+
+            public bool TryLookup(int key, out XmlDictionaryString result)
+            {
+                if (key == 0)
+                {
+                    result = empty;
+                    return true;
+                }
+                result = null;
+                return false;
+            }
+
+            public bool TryLookup(XmlDictionaryString value, out XmlDictionaryString result)
+            {
+                if (value == null)
+                    throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException("value"));
+                if (value.Dictionary != this)
+                {
+                    result = null;
+                    return false;
+                }
+                result = value;
+                return true;
+            }
+        }
+    }
+}