From: gmungoc <g.m.carstairs@dundee.ac.uk>
Date: Wed, 6 May 2015 14:30:00 +0000 (+0100)
Subject: JAL-1725 limit thread pool size; prefix /jalview to paths
X-Git-Tag: Jalview_2_9~31
X-Git-Url: http://source.jalview.org/gitweb/?p=jalview.git;a=commitdiff_plain;h=bf1ef95b21f5a0c470e33c6cf10022cc732f0df5

JAL-1725 limit thread pool size; prefix /jalview to paths
---

diff --git a/src/jalview/httpserver/HttpServer.java b/src/jalview/httpserver/HttpServer.java
index 6f4aa75..e60db9a 100644
--- a/src/jalview/httpserver/HttpServer.java
+++ b/src/jalview/httpserver/HttpServer.java
@@ -11,19 +11,29 @@ import javax.servlet.http.HttpServletResponse;
 
 import org.eclipse.jetty.server.Handler;
 import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.server.handler.ContextHandler;
 import org.eclipse.jetty.server.handler.HandlerCollection;
 import org.eclipse.jetty.util.thread.QueuedThreadPool;
 
 /**
- * An HttpServer built on Jetty
+ * An HttpServer built on Jetty. To use it
+ * <ul>
+ * <li>call getInstance() to create and start the server</li>
+ * <li>call registerHandler to add a handler for a path (below /jalview)</li>
+ * <li>when finished, call removedHandler</li>
+ * </ul>
  * 
  * @author gmcarstairs
  * @see http://eclipse.org/jetty/documentation/current/embedding-jetty.html
  */
 public class HttpServer
 {
-  private static final String JALVIEW_PATH = "/jalview";
+  /*
+   * 'context root' - actually just prefixed to the path for each handler for
+   * now - see registerHandler
+   */
+  private static final String JALVIEW_PATH = "jalview";
 
   /*
    * Singleton instance of this server
@@ -79,7 +89,7 @@ public class HttpServer
   }
 
   /**
-   * Start the http server with a default thread pool size of 1
+   * Start the http server
    * 
    * @throws BindException
    */
@@ -87,11 +97,15 @@ public class HttpServer
   {
     try
     {
-      // problem: how to both limit thread pool size and
-      // pick a random free port - two alternative constructors
-      QueuedThreadPool tp = new QueuedThreadPool(1, 1);
-      // server = new Server(tp); // ? fails with URI null
-      server = new Server(0); // pick a free port number
+      /*
+       * Create a server with a small number of threads; jetty will allocate a
+       * free port
+       */
+      QueuedThreadPool tp = new QueuedThreadPool(4, 1); // max, min
+      server = new Server(tp);
+      // 2 selector threads to handle incoming connections
+      ServerConnector connector = new ServerConnector(server, 0, 2);
+      server.addConnector(connector);
 
       /*
        * HttpServer shuts down with Jalview process
@@ -100,13 +114,15 @@ public class HttpServer
 
       /*
        * Create a mutable set of handlers (can add handlers while the server is
-       * running)
+       * running). Using vanilla handlers here rather than servlets
        */
-      // TODO how to combine this with context root "/jalview"
+      // TODO how to properly configure context root "/jalview"
       contextHandlers = new HandlerCollection(true);
       server.setHandler(contextHandlers);
-
       server.start();
+      // System.out.println(String.format(
+      // "HttpServer started with %d threads", server.getThreadPool()
+      // .getThreads()));
       contextRoot = server.getURI();
       System.out.println("Jalview endpoint " + contextRoot);
     } catch (Exception e)
@@ -197,7 +213,7 @@ public class HttpServer
     // http://stackoverflow.com/questions/20043097/jetty-9-embedded-adding-handlers-during-runtime
     ContextHandler ch = new ContextHandler();
     ch.setAllowNullPathInfo(true);
-    ch.setContextPath("/" + path);
+    ch.setContextPath("/" + JALVIEW_PATH + "/" + path);
     ch.setResourceBase(".");
     ch.setClassLoader(Thread.currentThread()
             .getContextClassLoader());