Creating a branch for experimenting with some ideas for JMS client.rajith_jms_client

git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/rajith_jms_client@1128369 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 327 insertions, 0 deletions

diff --git a/qpid/dotnet/Qpid.Common/Collections/LinkedHashtable.cs b/qpid/dotnet/Qpid.Common/Collections/LinkedHashtable.cs
new file mode 100644
index 0000000000..10ab5c674d
--- /dev/null
+++ b/qpid/dotnet/Qpid.Common/Collections/LinkedHashtable.cs
@@ -0,0 +1,327 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+using System;
+using System.Collections;
+
+namespace Apache.Qpid.Collections
+{
+    public class LinkedHashtable : IDictionary
+    {
+        /// <summary>
+        /// Maps from key to LinkedDictionaryEntry        
+        /// </summary>
+        private Hashtable _indexedValues = new Hashtable();
+
+        private LinkedDictionaryEntry _head;
+
+        private LinkedDictionaryEntry _tail;
+
+        private class LinkedDictionaryEntry
+        {
+            public LinkedDictionaryEntry _previous;
+            public LinkedDictionaryEntry _next;
+            internal DictionaryEntry _entry;
+
+            public LinkedDictionaryEntry(object key, object value)
+            {
+                _entry = new DictionaryEntry(key, value);
+            }
+        }
+
+        public object this[object key]
+        {
+            get
+            {
+                LinkedDictionaryEntry entry = (LinkedDictionaryEntry)_indexedValues[key];
+                if (entry == null)
+                {
+                    return null; // key not found
+                }
+                else
+                {
+                    return entry._entry.Value;
+                }
+            }
+
+            set
+            {
+                LinkedDictionaryEntry entry = (LinkedDictionaryEntry)_indexedValues[key];
+                if (entry == null)
+                {
+                    Add(key, value);
+                }
+                else
+                {
+                    entry._entry.Value = value;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Collect keys in linked order.
+        /// </summary>
+        public ICollection Keys
+        {
+            get
+            {
+                IList result = new ArrayList();
+                foreach (DictionaryEntry entry in this)
+                {
+                    result.Add(entry.Key);
+                }
+                return result;
+            }
+        }
+
+        /// <summary>
+        /// Collect values in linked order.
+        /// </summary>
+        public ICollection Values
+        {
+            get
+            {
+                IList result = new ArrayList();
+                foreach (DictionaryEntry entry in this)
+                {
+                    result.Add(entry.Value);
+                }
+                return result;
+            }
+        }
+
+        public bool IsReadOnly
+        {
+            get { return _indexedValues.IsReadOnly; }
+        }
+
+        public bool IsFixedSize
+        {
+            get { return _indexedValues.IsFixedSize; }
+        }
+
+        public bool Contains(object key)
+        {
+            return _indexedValues.Contains(key);
+        }
+
+        public void Add(object key, object value)
+        {
+            if (key == null) throw new ArgumentNullException("key");
+            
+            if (Contains(key))
+            {
+                throw new ArgumentException("LinkedHashtable already contains key. key=" + key);
+            }
+            
+            LinkedDictionaryEntry de = new LinkedDictionaryEntry(key, value);
+            if (_head == null)
+            {
+                _head = de;
+                _tail = de;
+            }
+            else
+            {
+                _tail._next = de;
+                de._previous = _tail;
+                _tail = de;
+            }
+            _indexedValues[key] = de;
+        }
+
+        public void Clear()
+        {
+            _indexedValues.Clear();
+        }
+
+        IDictionaryEnumerator IDictionary.GetEnumerator()
+        {
+            return new LHTEnumerator(this);
+        }
+
+        public void Remove(object key)
+        {
+            if (key == null) throw new ArgumentNullException("key");
+            
+            LinkedDictionaryEntry de = (LinkedDictionaryEntry)_indexedValues[key];
+            if (de == null) return; // key not found.
+            LinkedDictionaryEntry prev = de._previous;
+            if (prev == null)
+            {
+                _head = de._next;
+            }
+            else
+            {
+                prev._next = de._next;
+            }
+
+            LinkedDictionaryEntry next = de._next;
+            if (next == null)
+            {
+                _tail = de;
+            }
+            else
+            {
+                next._previous = de._previous;
+            }
+        }
+        
+        private LinkedDictionaryEntry Head
+        {
+            get
+            {
+                return _head;
+            }
+        }
+
+//        private LinkedDictionaryEntry Tail
+//        {
+//            get
+//            {
+//                return _tail;
+//            }
+//        }
+
+        private class LHTEnumerator : IDictionaryEnumerator
+        {
+            private LinkedHashtable _container;
+
+            private LinkedDictionaryEntry _current;
+
+            /// <summary>
+            /// Set once we have navigated off the end of the collection
+            /// </summary>
+            private bool _needsReset = false;
+
+            public LHTEnumerator(LinkedHashtable container)
+            {
+                _container = container;                
+            }
+
+            public object Current
+            {
+                get
+                {
+                    if (_current == null)
+                    {
+                        throw new Exception("Iterator before first element");
+                    }
+                    else
+                    {
+                        return _current._entry;
+                    }
+                }
+            }
+
+            public object Key
+            {
+                get { return _current._entry.Key; }
+            }
+
+            public object Value
+            {
+                get { return _current._entry.Value; }
+            }
+
+            public DictionaryEntry Entry
+            {
+                get
+                {
+                    return _current._entry;
+                }
+            }
+
+            public bool MoveNext()
+            {
+                if (_needsReset)
+                {
+                    return false;
+                }
+                else if (_current == null)
+                {
+                    _current = _container.Head;                    
+                }
+                else
+                {
+                    _current = _current._next;
+                }
+                _needsReset = (_current == null);
+                return !_needsReset;                
+            }
+
+            public void Reset()
+            {
+                _current = null;
+                _needsReset = false;
+            }
+        }
+
+        public void MoveToHead(object key)
+        {
+            LinkedDictionaryEntry de = (LinkedDictionaryEntry)_indexedValues[key];
+            if (de == null)
+            {
+                throw new ArgumentException("Key " + key + " not found");
+            }
+            // if the head is the element then there is nothing to do
+            if (_head == de)
+            {
+                return;
+            }
+            de._previous._next = de._next;
+            if (de._next != null)
+            {
+                de._next._previous = de._previous;
+            }
+            else
+            {
+                _tail = de._previous;
+            }
+            de._next = _head;
+            _head = de;
+            de._previous = null;
+        }
+
+        public void CopyTo(Array array, int index)
+        {
+            _indexedValues.CopyTo(array, index);
+        }
+
+        public int Count
+        {
+            get { return _indexedValues.Count; }
+        }
+
+        public object SyncRoot
+        {
+            get { return _indexedValues.SyncRoot; }
+        }
+
+        public bool IsSynchronized
+        {
+            get { return _indexedValues.IsSynchronized; }
+        }
+
+        public IEnumerator GetEnumerator()
+        {
+            return new LHTEnumerator(this);
+        }
+    }
+}