Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/ServiceModelDictionary.cs

@@ -0,0 +1,121 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+namespace System.ServiceModel
+{
+    using System.Xml;
+    using System.Collections.Generic;
+
+    class ServiceModelDictionary : IXmlDictionary
+    {
+        static public readonly ServiceModelDictionary Version1 = new ServiceModelDictionary(new ServiceModelStringsVersion1());
+        ServiceModelStrings strings;
+        int count;
+        XmlDictionaryString[] dictionaryStrings1;
+        XmlDictionaryString[] dictionaryStrings2;
+        Dictionary<string, int> dictionary;
+        XmlDictionaryString[] versionedDictionaryStrings;
+
+        public ServiceModelDictionary(ServiceModelStrings strings)
+        {
+            this.strings = strings;
+            this.count = strings.Count;
+        }
+
+        static public ServiceModelDictionary CurrentVersion
+        {
+            get
+            {
+                return Version1;
+            }
+        }
+
+        public XmlDictionaryString CreateString(string value, int key)
+        {
+            return new XmlDictionaryString(this, value, key);
+        }
+
+        public bool TryLookup(string key, out XmlDictionaryString value)
+        {
+            if (key == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException("key"));
+            if (this.dictionary == null)
+            {
+                Dictionary<string, int> dictionary = new Dictionary<string, int>(count);
+                for (int i = 0; i < count; i++)
+                    dictionary.Add(strings[i], i);
+                this.dictionary = dictionary;
+            }
+            int id;
+            if (this.dictionary.TryGetValue(key, out id))
+                return TryLookup(id, out value);
+            value = null;
+            return false;
+        }
+
+        public bool TryLookup(int key, out XmlDictionaryString value)
+        {
+            const int keyThreshold = 32;
+            if (key < 0 || key >= count)
+            {
+                value = null;
+                return false;
+            }
+            XmlDictionaryString s;
+            if (key < keyThreshold)
+            {
+                if (dictionaryStrings1 == null)
+                    dictionaryStrings1 = new XmlDictionaryString[keyThreshold];
+                s = dictionaryStrings1[key];
+                if (s == null)
+                {
+                    s = CreateString(strings[key], key);
+                    dictionaryStrings1[key] = s;
+                }
+            }
+            else
+            {
+                if (dictionaryStrings2 == null)
+                    dictionaryStrings2 = new XmlDictionaryString[count - keyThreshold];
+                s = dictionaryStrings2[key - keyThreshold];
+                if (s == null)
+                {
+                    s = CreateString(strings[key], key);
+                    dictionaryStrings2[key - keyThreshold] = s;
+                }
+            }
+            value = s;
+            return true;
+        }
+
+        public bool TryLookup(XmlDictionaryString key, out XmlDictionaryString value)
+        {
+            if (key == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException("key"));
+            if (key.Dictionary == this)
+            {
+                value = key;
+                return true;
+            }
+            if (key.Dictionary == CurrentVersion)
+            {
+                if (versionedDictionaryStrings == null)
+                    versionedDictionaryStrings = new XmlDictionaryString[CurrentVersion.count];
+                XmlDictionaryString s = versionedDictionaryStrings[key.Key];
+                if (s == null)
+                {
+                    if (!TryLookup(key.Value, out s))
+                    {
+                        value = null;
+                        return false;
+                    }
+                    versionedDictionaryStrings[key.Key] = s;
+                }
+                value = s;
+                return true;
+            }
+            value = null;
+            return false;
+        }
+    }
+}