1 files changed, 681 insertions, 0 deletions

diff --git a/OpenSim/Framework/RestClient.cs b/OpenSim/Framework/RestClient.cs
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--- /dev/null
+++ b/OpenSim/Framework/RestClient.cs
@@ -0,0 +1,681 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using System.Reflection;
+using System.Text;
+using System.Threading;
+using System.Web;
+using log4net;
+
+using OpenSim.Framework.ServiceAuth;
+
+namespace OpenSim.Framework
+{
+    /// <summary>
+    /// Implementation of a generic REST client
+    /// </summary>
+    /// <remarks>
+    /// This class is a generic implementation of a REST (Representational State Transfer) web service. This
+    /// class is designed to execute both synchronously and asynchronously.
+    ///
+    /// Internally the implementation works as a two stage asynchronous web-client.
+    /// When the request is initiated, RestClient will query asynchronously for for a web-response,
+    /// sleeping until the initial response is returned by the server. Once the initial response is retrieved
+    /// the second stage of asynchronous requests will be triggered, in an attempt to read of the response
+    /// object into a memorystream as a sequence of asynchronous reads.
+    ///
+    /// The asynchronisity of RestClient is designed to move as much processing into the back-ground, allowing
+    /// other threads to execute, while it waits for a response from the web-service. RestClient itself can be
+    /// invoked by the caller in either synchronous mode or asynchronous modes.
+    /// </remarks>
+    public class RestClient : IDisposable
+    {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        // private string realuri;
+
+        #region member variables
+
+        /// <summary>
+        /// The base Uri of the web-service e.g. http://www.google.com
+        /// </summary>
+        private string _url;
+
+        /// <summary>
+        /// Path elements of the query
+        /// </summary>
+        private List<string> _pathElements = new List<string>();
+
+        /// <summary>
+        /// Parameter elements of the query, e.g. min=34
+        /// </summary>
+        private Dictionary<string, string> _parameterElements = new Dictionary<string, string>();
+
+        /// <summary>
+        /// Request method. E.g. GET, POST, PUT or DELETE
+        /// </summary>
+        private string _method;
+
+        /// <summary>
+        /// Temporary buffer used to store bytes temporarily as they come in from the server
+        /// </summary>
+        private byte[] _readbuf;
+
+        /// <summary>
+        /// MemoryStream representing the resulting resource
+        /// </summary>
+        private Stream _resource;
+
+        /// <summary>
+        /// WebRequest object, held as a member variable
+        /// </summary>
+        private HttpWebRequest _request;
+
+        /// <summary>
+        /// WebResponse object, held as a member variable, so we can close it
+        /// </summary>
+        private HttpWebResponse _response;
+
+        /// <summary>
+        /// This flag will help block the main synchroneous method, in case we run in synchroneous mode
+        /// </summary>
+        //public static ManualResetEvent _allDone = new ManualResetEvent(false);
+
+        /// <summary>
+        /// Default time out period
+        /// </summary>
+        //private const int DefaultTimeout = 10*1000; // 10 seconds timeout
+
+        /// <summary>
+        /// Default Buffer size of a block requested from the web-server
+        /// </summary>
+        private const int BufferSize = 4096; // Read blocks of 4 KB.
+
+
+        /// <summary>
+        /// if an exception occours during async processing, we need to save it, so it can be
+        /// rethrown on the primary thread;
+        /// </summary>
+        private Exception _asyncException;
+
+        #endregion member variables
+
+        #region constructors
+
+        /// <summary>
+        /// Instantiate a new RestClient
+        /// </summary>
+        /// <param name="url">Web-service to query, e.g. http://osgrid.org:8003</param>
+        public RestClient(string url)
+        {
+            _url = url;
+            _readbuf = new byte[BufferSize];
+            _resource = new MemoryStream();
+            _request = null;
+            _response = null;
+            _lock = new object();
+        }
+
+        private object _lock;
+
+        #endregion constructors
+
+
+        #region Dispose
+
+        private bool disposed = false;
+
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this); 
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposed)
+                return;
+
+            if (disposing)
+            {
+                _resource.Dispose();
+            }
+
+            disposed = true;
+        }
+
+        #endregion Dispose
+
+
+        /// <summary>
+        /// Add a path element to the query, e.g. assets
+        /// </summary>
+        /// <param name="element">path entry</param>
+        public void AddResourcePath(string element)
+        {
+            if (isSlashed(element))
+                _pathElements.Add(element.Substring(0, element.Length - 1));
+            else
+                _pathElements.Add(element);
+        }
+
+        /// <summary>
+        /// Add a query parameter to the Url
+        /// </summary>
+        /// <param name="name">Name of the parameter, e.g. min</param>
+        /// <param name="value">Value of the parameter, e.g. 42</param>
+        public void AddQueryParameter(string name, string value)
+        {
+            try
+            {
+                _parameterElements.Add(HttpUtility.UrlEncode(name), HttpUtility.UrlEncode(value));
+            }
+            catch (ArgumentException)
+            {
+                m_log.Error("[REST]: Query parameter " + name + " is already added.");
+            }
+            catch (Exception e)
+            {
+                m_log.Error("[REST]: An exception was raised adding query parameter to dictionary. Exception: {0}",e);
+            }
+        }
+
+        /// <summary>
+        /// Add a query parameter to the Url
+        /// </summary>
+        /// <param name="name">Name of the parameter, e.g. min</param>
+        public void AddQueryParameter(string name)
+        {
+            try
+            {
+                _parameterElements.Add(HttpUtility.UrlEncode(name), null);
+            }
+            catch (ArgumentException)
+            {
+                m_log.Error("[REST]: Query parameter " + name + " is already added.");
+            }
+            catch (Exception e)
+            {
+                m_log.Error("[REST]: An exception was raised adding query parameter to dictionary. Exception: {0}",e);
+            }
+        }
+
+        /// <summary>
+        /// Web-Request method, e.g. GET, PUT, POST, DELETE
+        /// </summary>
+        public string RequestMethod
+        {
+            get { return _method; }
+            set { _method = value; }
+        }
+
+        /// <summary>
+        /// True if string contains a trailing slash '/'
+        /// </summary>
+        /// <param name="s">string to be examined</param>
+        /// <returns>true if slash is present</returns>
+        private static bool isSlashed(string s)
+        {
+            return s.Substring(s.Length - 1, 1) == "/";
+        }
+
+        /// <summary>
+        /// Build a Uri based on the initial Url, path elements and parameters
+        /// </summary>
+        /// <returns>fully constructed Uri</returns>
+        private Uri buildUri()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.Append(_url);
+
+            foreach (string e in _pathElements)
+            {
+                sb.Append("/");
+                sb.Append(e);
+            }
+
+            bool firstElement = true;
+            foreach (KeyValuePair<string, string> kv in _parameterElements)
+            {
+                if (firstElement)
+                {
+                    sb.Append("?");
+                    firstElement = false;
+                }
+                else
+                    sb.Append("&");
+
+                sb.Append(kv.Key);
+                if (!string.IsNullOrEmpty(kv.Value))
+                {
+                    sb.Append("=");
+                    sb.Append(kv.Value);
+                }
+            }
+            // realuri = sb.ToString();
+            //m_log.InfoFormat("[REST CLIENT]: RestURL: {0}", realuri);
+            return new Uri(sb.ToString());
+        }
+
+        #region Async communications with server
+
+        /// <summary>
+        /// Async method, invoked when a block of data has been received from the service
+        /// </summary>
+        /// <param name="ar"></param>
+        private void StreamIsReadyDelegate(IAsyncResult ar)
+        {
+            try
+            {
+                Stream s = (Stream) ar.AsyncState;
+                int read = s.EndRead(ar);
+
+                if (read > 0)
+                {
+                    _resource.Write(_readbuf, 0, read);
+                    // IAsyncResult asynchronousResult =
+                    //     s.BeginRead(_readbuf, 0, BufferSize, new AsyncCallback(StreamIsReadyDelegate), s);
+                    s.BeginRead(_readbuf, 0, BufferSize, new AsyncCallback(StreamIsReadyDelegate), s);
+
+                    // TODO! Implement timeout, without killing the server
+                    //ThreadPool.RegisterWaitForSingleObject(asynchronousResult.AsyncWaitHandle, new WaitOrTimerCallback(TimeoutCallback), _request, DefaultTimeout, true);
+                }
+                else
+                {
+                    s.Close();
+                    //_allDone.Set();
+                }
+            }
+            catch (Exception e)
+            {
+                //_allDone.Set();
+                _asyncException = e;
+            }
+        }
+
+        #endregion Async communications with server
+
+        /// <summary>
+        /// Perform a synchronous request
+        /// </summary>
+        public Stream Request()
+        {
+            return Request(null);
+        }
+
+        /// <summary>
+        /// Perform a synchronous request
+        /// </summary>
+        public Stream Request(IServiceAuth auth)
+        {
+            lock (_lock)
+            {
+                _request = (HttpWebRequest) WebRequest.Create(buildUri());
+                _request.KeepAlive = false;
+                _request.ContentType = "application/xml";
+                _request.Timeout = 200000;
+                _request.Method = RequestMethod;
+                _asyncException = null;
+                if (auth != null)
+                    auth.AddAuthorization(_request.Headers);
+
+                int reqnum = WebUtil.RequestNumber++;
+                if (WebUtil.DebugLevel >= 3)
+                    m_log.DebugFormat("[LOGHTTP]: HTTP OUT {0} REST {1} to {2}", reqnum, _request.Method, _request.RequestUri);
+
+//                IAsyncResult responseAsyncResult = _request.BeginGetResponse(new AsyncCallback(ResponseIsReadyDelegate), _request);
+
+                try
+                {
+                    using (_response = (HttpWebResponse) _request.GetResponse())
+                    {
+                        using (Stream src = _response.GetResponseStream())
+                        {
+                            int length = src.Read(_readbuf, 0, BufferSize);
+                            while (length > 0)
+                            {
+                                _resource.Write(_readbuf, 0, length);
+                                length = src.Read(_readbuf, 0, BufferSize);
+                            }
+
+                            // TODO! Implement timeout, without killing the server
+                            // this line implements the timeout, if there is a timeout, the callback fires and the request becomes aborted
+                            //ThreadPool.RegisterWaitForSingleObject(responseAsyncResult.AsyncWaitHandle, new WaitOrTimerCallback(TimeoutCallback), _request, DefaultTimeout, true);
+
+                            //                _allDone.WaitOne();
+                        }
+                    }
+                }
+                catch (WebException e)
+                {
+                    using (HttpWebResponse errorResponse = e.Response as HttpWebResponse)
+                    {
+                        if (null != errorResponse && HttpStatusCode.NotFound == errorResponse.StatusCode)
+                        {
+                            // This is often benign. E.g., requesting a missing asset will return 404.
+                            m_log.DebugFormat("[REST CLIENT] Resource not found (404): {0}", _request.Address.ToString());
+                        }
+                        else
+                        {
+                            m_log.Error(string.Format("[REST CLIENT] Error fetching resource from server: {0} ", _request.Address.ToString()), e);
+                        }
+                    }
+                    return null;
+                }
+
+
+                if (_asyncException != null)
+                    throw _asyncException;
+
+                if (_resource != null)
+                {
+                    _resource.Flush();
+                    _resource.Seek(0, SeekOrigin.Begin);
+                }
+
+                if (WebUtil.DebugLevel >= 5)
+                    WebUtil.LogResponseDetail(reqnum, _resource);
+
+                return _resource;
+            }
+        }
+
+        public Stream Request(Stream src, IServiceAuth auth)
+        {
+            _request = (HttpWebRequest) WebRequest.Create(buildUri());
+            _request.KeepAlive = false;
+            _request.ContentType = "application/xml";
+            _request.Timeout = 90000;
+            _request.Method = RequestMethod;
+            _asyncException = null;
+            _request.ContentLength = src.Length;
+            if (auth != null)
+                auth.AddAuthorization(_request.Headers);
+
+            src.Seek(0, SeekOrigin.Begin);
+
+            int reqnum = WebUtil.RequestNumber++;
+            if (WebUtil.DebugLevel >= 3)
+                m_log.DebugFormat("[LOGHTTP]: HTTP OUT {0} REST {1} to {2}", reqnum, _request.Method, _request.RequestUri);
+            if (WebUtil.DebugLevel >= 5)
+                WebUtil.LogOutgoingDetail(string.Format("SEND {0}: ", reqnum), src);
+
+            using (Stream dst = _request.GetRequestStream())
+            {
+                m_log.Info("[REST]: GetRequestStream is ok");
+
+                byte[] buf = new byte[1024];
+                int length = src.Read(buf, 0, 1024);
+                m_log.Info("[REST]: First Read is ok");
+                while (length > 0)
+                {
+                    dst.Write(buf, 0, length);
+                    length = src.Read(buf, 0, 1024);
+                }
+            }
+
+            try
+            {
+                _response = (HttpWebResponse)_request.GetResponse();
+            }
+            catch (WebException e)
+            {
+                m_log.WarnFormat("[REST]: Request {0} {1} failed with status {2} and message {3}",
+                                  RequestMethod, _request.RequestUri, e.Status, e.Message);
+                return null;
+            }
+            catch (Exception e)
+            {
+                m_log.WarnFormat(
+                    "[REST]: Request {0} {1} failed with exception {2} {3}",
+                    RequestMethod, _request.RequestUri, e.Message, e.StackTrace);
+                return null;
+            }
+
+            if (WebUtil.DebugLevel >= 5)
+            {
+                using (Stream responseStream = _response.GetResponseStream())
+                {
+                    using (StreamReader reader = new StreamReader(responseStream))
+                    {
+                        string responseStr = reader.ReadToEnd();
+                        WebUtil.LogResponseDetail(reqnum, responseStr);
+                    }
+                }
+            }
+
+            if (_response != null)
+                _response.Close();
+
+//            IAsyncResult responseAsyncResult = _request.BeginGetResponse(new AsyncCallback(ResponseIsReadyDelegate), _request);
+
+            // TODO! Implement timeout, without killing the server
+            // this line implements the timeout, if there is a timeout, the callback fires and the request becomes aborted
+            //ThreadPool.RegisterWaitForSingleObject(responseAsyncResult.AsyncWaitHandle, new WaitOrTimerCallback(TimeoutCallback), _request, DefaultTimeout, true);
+
+            return null;
+        }
+
+        #region Async Invocation
+
+        public IAsyncResult BeginRequest(AsyncCallback callback, object state)
+        {
+            /// <summary>
+            /// In case, we are invoked asynchroneously this object will keep track of the state
+            /// </summary>
+            AsyncResult<Stream> ar = new AsyncResult<Stream>(callback, state);
+            Util.FireAndForget(RequestHelper, ar, "RestClient.BeginRequest");
+            return ar;
+        }
+
+        public Stream EndRequest(IAsyncResult asyncResult)
+        {
+            AsyncResult<Stream> ar = (AsyncResult<Stream>) asyncResult;
+
+            // Wait for operation to complete, then return result or
+            // throw exception
+            return ar.EndInvoke();
+        }
+
+        private void RequestHelper(Object asyncResult)
+        {
+            // We know that it's really an AsyncResult<DateTime> object
+            AsyncResult<Stream> ar = (AsyncResult<Stream>) asyncResult;
+            try
+            {
+                // Perform the operation; if sucessful set the result
+                Stream s = Request(null);
+                ar.SetAsCompleted(s, false);
+            }
+            catch (Exception e)
+            {
+                // If operation fails, set the exception
+                ar.HandleException(e, false);
+            }
+        }
+
+        #endregion Async Invocation
+    }
+
+    internal class SimpleAsyncResult : IAsyncResult
+    {
+        private readonly AsyncCallback m_callback;
+
+        /// <summary>
+        /// Is process completed?
+        /// </summary>
+        /// <remarks>Should really be boolean, but VolatileRead has no boolean method</remarks>
+        private byte m_completed;
+
+        /// <summary>
+        /// Did process complete synchronously?
+        /// </summary>
+        /// <remarks>I have a hard time imagining a scenario where this is the case, again, same issue about
+        /// booleans and VolatileRead as m_completed
+        /// </remarks>
+        private byte m_completedSynchronously;
+
+        private readonly object m_asyncState;
+        private ManualResetEvent m_waitHandle;
+        private Exception m_exception;
+
+        internal SimpleAsyncResult(AsyncCallback cb, object state)
+        {
+            m_callback = cb;
+            m_asyncState = state;
+            m_completed = 0;
+            m_completedSynchronously = 1;
+        }
+
+        #region IAsyncResult Members
+
+        public object AsyncState
+        {
+            get { return m_asyncState; }
+        }
+
+        public WaitHandle AsyncWaitHandle
+        {
+            get
+            {
+                if (m_waitHandle == null)
+                {
+                    bool done = IsCompleted;
+                    ManualResetEvent mre = new ManualResetEvent(done);
+                    if (Interlocked.CompareExchange(ref m_waitHandle, mre, null) != null)
+                    {
+                        mre.Close();
+                    }
+                    else
+                    {
+                        if (!done && IsCompleted)
+                        {
+                            m_waitHandle.Set();
+                        }
+                    }
+                }
+
+                return m_waitHandle;
+            }
+        }
+
+
+        public bool CompletedSynchronously
+        {
+            get { return Thread.VolatileRead(ref m_completedSynchronously) == 1; }
+        }
+
+
+        public bool IsCompleted
+        {
+            get { return Thread.VolatileRead(ref m_completed) == 1; }
+        }
+
+        #endregion
+
+        #region class Methods
+
+        internal void SetAsCompleted(bool completedSynchronously)
+        {
+            m_completed = 1;
+            if (completedSynchronously)
+                m_completedSynchronously = 1;
+            else
+                m_completedSynchronously = 0;
+
+            SignalCompletion();
+        }
+
+        internal void HandleException(Exception e, bool completedSynchronously)
+        {
+            m_completed = 1;
+            if (completedSynchronously)
+                m_completedSynchronously = 1;
+            else
+                m_completedSynchronously = 0;
+            m_exception = e;
+
+            SignalCompletion();
+        }
+
+        private void SignalCompletion()
+        {
+            if (m_waitHandle != null) m_waitHandle.Set();
+
+            if (m_callback != null) m_callback(this);
+        }
+
+        public void EndInvoke()
+        {
+            // This method assumes that only 1 thread calls EndInvoke
+            if (!IsCompleted)
+            {
+                // If the operation isn't done, wait for it
+                AsyncWaitHandle.WaitOne();
+                AsyncWaitHandle.Close();
+                m_waitHandle.Close();
+                m_waitHandle = null; // Allow early GC
+            }
+
+            // Operation is done: if an exception occured, throw it
+            if (m_exception != null) throw m_exception;
+        }
+
+        #endregion
+    }
+
+    internal class AsyncResult<T> : SimpleAsyncResult
+    {
+        private T m_result = default(T);
+
+        public AsyncResult(AsyncCallback asyncCallback, Object state) :
+            base(asyncCallback, state)
+        {
+        }
+
+        public void SetAsCompleted(T result, bool completedSynchronously)
+        {
+            // Save the asynchronous operation's result
+            m_result = result;
+
+            // Tell the base class that the operation completed
+            // sucessfully (no exception)
+            base.SetAsCompleted(completedSynchronously);
+        }
+
+        public new T EndInvoke()
+        {
+            base.EndInvoke();
+            return m_result;
+        }
+    }
+
+}