Performance improvements to HTTP client after profiling session.

The profiling suggested to reduce the number of unneeded allocations
and this required a couple of API changes.

jetty-client/src/main/java/org/eclipse/jetty/client/AuthenticationProtocolHandler.java

@@ -18,6 +18,7 @@
 
 package org.eclipse.jetty.client;
 
+import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -98,7 +99,7 @@ public class AuthenticationProtocolHandler implements ProtocolHandler
                 return;
             }
 
-            final String uri = request.getURI();
+            final URI uri = request.getURI();
             Authentication authentication = null;
             WWWAuthenticate wwwAuthenticate = null;
             for (WWWAuthenticate wwwAuthn : wwwAuthenticates)
@@ -125,7 +126,7 @@ public class AuthenticationProtocolHandler implements ProtocolHandler
                 return;
             }
 
-            Request newRequest = client.copyRequest(request, request.getURI());
+            Request newRequest = client.copyRequest(request, uri);
             authnResult.apply(newRequest);
             newRequest.onResponseSuccess(new Response.SuccessListener()
             {

jetty-client/src/main/java/org/eclipse/jetty/client/HttpAuthenticationStore.java

@@ -18,6 +18,7 @@
 
 package org.eclipse.jetty.client;
 
+import java.net.URI;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -29,7 +30,7 @@ import org.eclipse.jetty.client.api.AuthenticationStore;
 public class HttpAuthenticationStore implements AuthenticationStore
 {
     private final List<Authentication> authentications = new CopyOnWriteArrayList<>();
-    private final Map<String, Authentication.Result> results = new ConcurrentHashMap<>();
+    private final Map<URI, Authentication.Result> results = new ConcurrentHashMap<>();
 
     @Override
     public void addAuthentication(Authentication authentication)
@@ -50,7 +51,7 @@ public class HttpAuthenticationStore implements AuthenticationStore
     }
 
     @Override
-    public Authentication findAuthentication(String type, String uri, String realm)
+    public Authentication findAuthentication(String type, URI uri, String realm)
     {
         for (Authentication authentication : authentications)
         {
@@ -79,12 +80,12 @@ public class HttpAuthenticationStore implements AuthenticationStore
     }
 
     @Override
-    public Authentication.Result findAuthenticationResult(String uri)
+    public Authentication.Result findAuthenticationResult(URI uri)
     {
         // TODO: I should match the longest URI
-        for (Map.Entry<String, Authentication.Result> entry : results.entrySet())
+        for (Map.Entry<URI, Authentication.Result> entry : results.entrySet())
         {
-            if (uri.startsWith(entry.getKey()))
+            if (uri.toString().startsWith(entry.getKey().toString()))
                 return entry.getValue();
         }
         return null;

jetty-client/src/main/java/org/eclipse/jetty/client/HttpClient.java

@@ -30,14 +30,15 @@ import java.nio.channels.SelectionKey;
 import java.nio.channels.SocketChannel;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Future;
@@ -111,10 +112,10 @@ public class HttpClient extends ContainerLifeCycle
 
     private final ConcurrentMap<String, HttpDestination> destinations = new ConcurrentHashMap<>();
     private final ConcurrentMap<Long, HttpConversation> conversations = new ConcurrentHashMap<>();
-    private final List<ProtocolHandler> handlers = new CopyOnWriteArrayList<>();
+    private final List<ProtocolHandler> handlers = new ArrayList<>();
-    private final List<Request.Listener> requestListeners = new CopyOnWriteArrayList<>();
+    private final List<Request.Listener> requestListeners = new ArrayList<>();
     private final AuthenticationStore authenticationStore = new HttpAuthenticationStore();
-    private final Set<ContentDecoder.Factory> decoderFactories = Collections.newSetFromMap(new ConcurrentHashMap<ContentDecoder.Factory, Boolean>());
+    private final Set<ContentDecoder.Factory> decoderFactories = new ContentDecoderFactorySet();
     private final SslContextFactory sslContextFactory;
     private volatile CookieManager cookieManager;
     private volatile CookieStore cookieStore;
@@ -122,7 +123,7 @@ public class HttpClient extends ContainerLifeCycle
     private volatile ByteBufferPool byteBufferPool;
     private volatile Scheduler scheduler;
     private volatile SelectorManager selectorManager;
-    private volatile String agent = "Jetty/" + Jetty.VERSION;
+    private volatile HttpField agentField = new HttpField(HttpHeader.USER_AGENT, "Jetty/" + Jetty.VERSION);
     private volatile boolean followRedirects = true;
     private volatile int maxConnectionsPerDestination = 64;
     private volatile int maxRequestsQueuedPerDestination = 1024;
@@ -135,6 +136,7 @@ public class HttpClient extends ContainerLifeCycle
     private volatile boolean tcpNoDelay = true;
     private volatile boolean dispatchIO = true;
     private volatile ProxyConfiguration proxyConfig;
+    private volatile HttpField encodingField;
 
     /**
      * Creates a {@link HttpClient} instance that can perform requests to non-TLS destinations only
@@ -249,6 +251,9 @@ public class HttpClient extends ContainerLifeCycle
     }
 
     /**
+     * Returns a <em>non</em> thread-safe list of {@link Request.Listener}s that can be modified before
+     * performing requests.
+     *
      * @return a list of {@link Request.Listener} that can be used to add and remove listeners
      */
     public List<Request.Listener> getRequestListeners()
@@ -293,6 +298,9 @@ public class HttpClient extends ContainerLifeCycle
     }
 
     /**
+     * Returns a <em>non</em> thread-safe set of {@link ContentDecoder.Factory}s that can be modified before
+     * performing requests.
+     *
      * @return a set of {@link ContentDecoder.Factory} that can be used to add and remove content decoder factories
      */
     public Set<ContentDecoder.Factory> getContentDecoderFactories()
@@ -381,9 +389,9 @@ public class HttpClient extends ContainerLifeCycle
         return new HttpRequest(this, uri);
     }
 
-    protected Request copyRequest(Request oldRequest, String newURI)
+    protected Request copyRequest(Request oldRequest, URI newURI)
     {
-        Request newRequest = new HttpRequest(this, oldRequest.getConversationID(), URI.create(newURI));
+        Request newRequest = new HttpRequest(this, oldRequest.getConversationID(), newURI);
         newRequest.method(oldRequest.getMethod())
                 .version(oldRequest.getVersion())
                 .content(oldRequest.getContent());
@@ -537,8 +545,11 @@ public class HttpClient extends ContainerLifeCycle
 
     protected ProtocolHandler findProtocolHandler(Request request, Response response)
     {
-        for (ProtocolHandler handler : getProtocolHandlers())
+        // Optimized to avoid allocations of iterator instances
+        List<ProtocolHandler> protocolHandlers = getProtocolHandlers();
+        for (int i = 0; i < protocolHandlers.size(); ++i)
         {
+            ProtocolHandler handler = protocolHandlers.get(i);
             if (handler.accept(request, response))
                 return handler;
         }
@@ -614,19 +625,21 @@ public class HttpClient extends ContainerLifeCycle
     }
 
     /**
-     * @return the "User-Agent" HTTP header string of this {@link HttpClient}
+     * @return the "User-Agent" HTTP field of this {@link HttpClient}
      */
-    public String getUserAgent()
+    public HttpField getUserAgentField()
     {
-        return agent;
+        return agentField;
     }
 
     /**
      * @param agent the "User-Agent" HTTP header string of this {@link HttpClient}
      */
-    public void setUserAgent(String agent)
+    public void setUserAgentField(HttpField agent)
     {
-        this.agent = agent;
+        if (agent.getHeader() != HttpHeader.USER_AGENT)
+            throw new IllegalArgumentException();
+        this.agentField = agent;
     }
 
     /**
@@ -844,6 +857,11 @@ public class HttpClient extends ContainerLifeCycle
         this.proxyConfig = proxyConfig;
     }
 
+    protected HttpField getAcceptEncodingField()
+    {
+        return encodingField;
+    }
+
     @Override
     public void dump(Appendable out, String indent) throws IOException
     {
@@ -930,4 +948,118 @@ public class HttpClient extends ContainerLifeCycle
             this.promise = promise;
         }
     }
+
+    private class ContentDecoderFactorySet implements Set<ContentDecoder.Factory>
+    {
+        private final Set<ContentDecoder.Factory> set = new HashSet<>();
+
+        @Override
+        public boolean add(ContentDecoder.Factory e)
+        {
+            boolean result = set.add(e);
+            invalidate();
+            return result;
+        }
+
+        @Override
+        public boolean addAll(Collection<? extends ContentDecoder.Factory> c)
+        {
+            boolean result = set.addAll(c);
+            invalidate();
+            return result;
+        }
+
+        @Override
+        public boolean remove(Object o)
+        {
+            boolean result = set.remove(o);
+            invalidate();
+            return result;
+        }
+
+        @Override
+        public boolean removeAll(Collection<?> c)
+        {
+            boolean result = set.removeAll(c);
+            invalidate();
+            return result;
+        }
+
+        @Override
+        public boolean retainAll(Collection<?> c)
+        {
+            boolean result = set.retainAll(c);
+            invalidate();
+            return result;
+        }
+
+        @Override
+        public void clear()
+        {
+            set.clear();
+            invalidate();
+        }
+
+        @Override
+        public int size()
+        {
+            return set.size();
+        }
+
+        @Override
+        public boolean isEmpty()
+        {
+            return set.isEmpty();
+        }
+
+        @Override
+        public boolean contains(Object o)
+        {
+            return set.contains(o);
+        }
+
+        @Override
+        public boolean containsAll(Collection<?> c)
+        {
+            return set.containsAll(c);
+        }
+
+        @Override
+        public Iterator<ContentDecoder.Factory> iterator()
+        {
+            return set.iterator();
+        }
+
+        @Override
+        public Object[] toArray()
+        {
+            return set.toArray();
+        }
+
+        @Override
+        public <T> T[] toArray(T[] a)
+        {
+            return set.toArray(a);
+        }
+
+        protected void invalidate()
+        {
+            if (set.isEmpty())
+            {
+                encodingField = null;
+            }
+            else
+            {
+                StringBuilder value = new StringBuilder();
+                for (Iterator<ContentDecoder.Factory> iterator = set.iterator(); iterator.hasNext();)
+                {
+                    ContentDecoder.Factory decoderFactory = iterator.next();
+                    value.append(decoderFactory.getEncoding());
+                    if (iterator.hasNext())
+                        value.append(",");
+                }
+                encodingField = new HttpField(HttpHeader.ACCEPT_ENCODING, value.toString());
+            }
+        }
+    }
 }

jetty-client/src/main/java/org/eclipse/jetty/client/HttpConnection.java

@@ -20,14 +20,12 @@ package org.eclipse.jetty.client;
 
 import java.io.UnsupportedEncodingException;
 import java.net.HttpCookie;
-import java.net.URI;
 import java.net.URLEncoder;
 import java.nio.charset.UnsupportedCharsetException;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -37,8 +35,10 @@ import org.eclipse.jetty.client.api.ContentProvider;
 import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.client.api.Response;
 import org.eclipse.jetty.client.util.StringContentProvider;
+import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
 import org.eclipse.jetty.http.HttpHeader;
+import org.eclipse.jetty.http.HttpHeaderValue;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MimeTypes;
@@ -51,6 +51,7 @@ import org.eclipse.jetty.util.log.Logger;
 public class HttpConnection extends AbstractConnection implements Connection
 {
     private static final Logger LOG = Log.getLogger(HttpConnection.class);
+    private static final HttpField CHUNKED_FIELD = new HttpField(HttpHeader.TRANSFER_ENCODING, HttpHeaderValue.CHUNKED);
 
     private final AtomicReference<HttpExchange> exchange = new AtomicReference<>();
     private final HttpClient client;
@@ -139,9 +140,6 @@ public class HttpConnection extends AbstractConnection implements Connection
         if (request.getVersion() == null)
             request.version(HttpVersion.HTTP_1_1);
 
-        if (request.getAgent() == null)
-            request.agent(client.getUserAgent());
-
         if (request.getIdleTimeout() <= 0)
             request.idleTimeout(client.getIdleTimeout(), TimeUnit.MILLISECONDS);
 
@@ -150,16 +148,19 @@ public class HttpConnection extends AbstractConnection implements Connection
         HttpFields headers = request.getHeaders();
         ContentProvider content = request.getContent();
 
+        if (request.getAgent() == null)
+            headers.put(client.getUserAgentField());
+
         // Make sure the path is there
         String path = request.getPath();
-        if (path.matches("\\s*"))
+        if (path.trim().length() == 0)
         {
             path = "/";
             request.path(path);
         }
         if (destination.isProxied() && HttpMethod.CONNECT != request.getMethod())
         {
-            path = request.getURI();
+            path = request.getURI().toString();
             request.path(path);
         }
 
@@ -208,13 +209,7 @@ public class HttpConnection extends AbstractConnection implements Connection
         if (version.getVersion() > 10)
         {
             if (!headers.containsKey(HttpHeader.HOST.asString()))
-            {
+                headers.put(getDestination().getHostField());
-                String value = request.getHost();
-                int port = request.getPort();
-                if (port > 0)
-                    value += ":" + port;
-                headers.put(HttpHeader.HOST, value);
-            }
         }
 
         // Add content headers
@@ -229,12 +224,12 @@ public class HttpConnection extends AbstractConnection implements Connection
             else
             {
                 if (!headers.containsKey(HttpHeader.TRANSFER_ENCODING.asString()))
-                    headers.put(HttpHeader.TRANSFER_ENCODING, "chunked");
+                    headers.put(CHUNKED_FIELD);
             }
         }
 
         // Cookies
-        List<HttpCookie> cookies = client.getCookieStore().get(URI.create(request.getURI()));
+        List<HttpCookie> cookies = client.getCookieStore().get(request.getURI());
         StringBuilder cookieString = null;
         for (int i = 0; i < cookies.size(); ++i)
         {
@@ -255,19 +250,9 @@ public class HttpConnection extends AbstractConnection implements Connection
 
         if (!headers.containsKey(HttpHeader.ACCEPT_ENCODING.asString()))
         {
-            Set<ContentDecoder.Factory> decoderFactories = client.getContentDecoderFactories();
+            HttpField acceptEncodingField = client.getAcceptEncodingField();
-            if (!decoderFactories.isEmpty())
+            if (acceptEncodingField != null)
-            {
+                headers.put(acceptEncodingField);
-                StringBuilder value = new StringBuilder();
-                for (Iterator<ContentDecoder.Factory> iterator = decoderFactories.iterator(); iterator.hasNext();)
-                {
-                    ContentDecoder.Factory decoderFactory = iterator.next();
-                    value.append(decoderFactory.getEncoding());
-                    if (iterator.hasNext())
-                        value.append(",");
-                }
-                headers.put(HttpHeader.ACCEPT_ENCODING, value.toString());
-            }
         }
     }
 

jetty-client/src/main/java/org/eclipse/jetty/client/HttpDestination.java

@@ -38,6 +38,7 @@ import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.client.api.Response;
 import org.eclipse.jetty.client.api.Result;
 import org.eclipse.jetty.client.util.TimedResponseListener;
+import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpScheme;
@@ -63,6 +64,7 @@ public class HttpDestination implements Destination, AutoCloseable, Dumpable
     private final RequestNotifier requestNotifier;
     private final ResponseNotifier responseNotifier;
     private final InetSocketAddress proxyAddress;
+    private final HttpField hostField;
 
     public HttpDestination(HttpClient client, String scheme, String host, int port)
     {
@@ -79,6 +81,12 @@ public class HttpDestination implements Destination, AutoCloseable, Dumpable
         ProxyConfiguration proxyConfig = client.getProxyConfiguration();
         proxyAddress = proxyConfig != null && proxyConfig.matches(host, port) ?
                 new InetSocketAddress(proxyConfig.getHost(), proxyConfig.getPort()) : null;
+
+        String hostValue = host;
+        if ("https".equalsIgnoreCase(scheme) && port != 443 ||
+                "http".equalsIgnoreCase(scheme) && port != 80)
+            hostValue += ":" + port;
+        hostField = new HttpField(HttpHeader.HOST, hostValue);
     }
 
     protected BlockingQueue<Connection> getIdleConnections()
@@ -121,6 +129,11 @@ public class HttpDestination implements Destination, AutoCloseable, Dumpable
         return proxyAddress != null;
     }
 
+    public HttpField getHostField()
+    {
+        return hostField;
+    }
+
     public void send(Request request, List<Response.ResponseListener> listeners)
     {
         if (!scheme.equals(request.getScheme()))

jetty-client/src/main/java/org/eclipse/jetty/client/HttpReceiver.java

@@ -224,13 +224,13 @@ public class HttpReceiver implements HttpParser.ResponseHandler<ByteBuffer>
         return false;
     }
 
-    private void storeCookie(String uri, HttpField field)
+    private void storeCookie(URI uri, HttpField field)
     {
         try
         {
             Map<String, List<String>> header = new HashMap<>(1);
             header.put(field.getHeader().asString(), Collections.singletonList(field.getValue()));
-            connection.getHttpClient().getCookieManager().put(URI.create(uri), header);
+            connection.getHttpClient().getCookieManager().put(uri, header);
         }
         catch (IOException x)
         {

jetty-client/src/main/java/org/eclipse/jetty/client/HttpRequest.java

@@ -59,6 +59,7 @@ public class HttpRequest implements Request
     private final long conversation;
     private final String host;
     private final int port;
+    private URI uri;
     private String scheme;
     private String path;
     private HttpMethod method;
@@ -91,6 +92,7 @@ public class HttpRequest implements Request
                 param(parts[0], parts.length < 2 ? "" : urlDecode(parts[1]));
             }
         }
+        this.uri = buildURI();
         followRedirects(client.isFollowRedirects());
     }
 
@@ -123,6 +125,7 @@ public class HttpRequest implements Request
     public Request scheme(String scheme)
     {
         this.scheme = scheme;
+        this.uri = buildURI();
         return this;
     }
 
@@ -161,19 +164,14 @@ public class HttpRequest implements Request
     public Request path(String path)
     {
         this.path = path;
+        this.uri = buildURI();
         return this;
     }
 
     @Override
-    public String getURI()
+    public URI getURI()
     {
-        String scheme = getScheme();
+        return uri;
-        String result = scheme + "://" + getHost();
-        int port = getPort();
-        result += "http".equals(scheme) && port != 80 ? ":" + port : "";
-        result += "https".equals(scheme) && port != 443 ? ":" + port : "";
-        result += getPath();
-        return result;
     }
 
     @Override
@@ -247,9 +245,14 @@ public class HttpRequest implements Request
     @Override
     public <T extends RequestListener> List<T> getRequestListeners(Class<T> type)
     {
+        // This method is invoked often in a request/response conversation,
+        // so we avoid allocation if there is no need to filter.
+        if (type == null)
+            return (List<T>)requestListeners;
+
         ArrayList<T> result = new ArrayList<>();
         for (RequestListener listener : requestListeners)
-            if (type == null || type.isInstance(listener))
+            if (type.isInstance(listener))
                 result.add((T)listener);
         return result;
     }
@@ -466,6 +469,11 @@ public class HttpRequest implements Request
         return aborted;
     }
 
+    private URI buildURI()
+    {
+        return URI.create(getScheme() + "://" + getHost() + ":" + getPort() + getPath());
+    }
+
     @Override
     public String toString()
     {

jetty-client/src/main/java/org/eclipse/jetty/client/RedirectProtocolHandler.java

@@ -18,6 +18,7 @@
 
 package org.eclipse.jetty.client;
 
+import java.net.URI;
 import java.util.List;
 
 import org.eclipse.jetty.client.api.Request;
@@ -65,7 +66,7 @@ public class RedirectProtocolHandler extends Response.Listener.Empty implements
         {
             Request request = result.getRequest();
             Response response = result.getResponse();
-            String location = response.getHeaders().get("location");
+            URI location = URI.create(response.getHeaders().get("location"));
             int status = response.getStatus();
             switch (status)
             {
@@ -103,7 +104,7 @@ public class RedirectProtocolHandler extends Response.Listener.Empty implements
         }
     }
 
-    private void redirect(Result result, HttpMethod method, String location)
+    private void redirect(Result result, HttpMethod method, URI location)
     {
         final Request request = result.getRequest();
         HttpConversation conversation = client.getConversation(request.getConversationID(), false);

jetty-client/src/main/java/org/eclipse/jetty/client/RequestNotifier.java

@@ -18,6 +18,8 @@
 
 package org.eclipse.jetty.client;
 
+import java.util.List;
+
 import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
@@ -35,17 +37,26 @@ public class RequestNotifier
 
     public void notifyQueued(Request request)
     {
-        for (Request.QueuedListener listener : request.getRequestListeners(Request.QueuedListener.class))
+        // Optimized to avoid allocations of iterator instances
-            notifyQueued(listener, request);
+        List<Request.RequestListener> requestListeners = request.getRequestListeners(null);
-        for (Request.Listener listener : client.getRequestListeners())
+        for (int i = 0; i < requestListeners.size(); ++i)
+        {
+            Request.RequestListener listener = requestListeners.get(i);
+            if (listener instanceof Request.QueuedListener)
+                notifyQueued((Request.QueuedListener)listener, request);
+        }
+        List<Request.Listener> listeners = client.getRequestListeners();
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Request.Listener listener = listeners.get(i);
             notifyQueued(listener, request);
         }
+    }
 
     private void notifyQueued(Request.QueuedListener listener, Request request)
     {
         try
         {
-            if (listener != null)
             listener.onQueued(request);
         }
         catch (Exception x)
@@ -56,17 +67,26 @@ public class RequestNotifier
 
     public void notifyBegin(Request request)
     {
-        for (Request.BeginListener listener : request.getRequestListeners(Request.BeginListener.class))
+        // Optimized to avoid allocations of iterator instances
-            notifyBegin(listener, request);
+        List<Request.RequestListener> requestListeners = request.getRequestListeners(null);
-        for (Request.Listener listener : client.getRequestListeners())
+        for (int i = 0; i < requestListeners.size(); ++i)
+        {
+            Request.RequestListener listener = requestListeners.get(i);
+            if (listener instanceof Request.BeginListener)
+                notifyBegin((Request.BeginListener)listener, request);
+        }
+        List<Request.Listener> listeners = client.getRequestListeners();
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Request.Listener listener = listeners.get(i);
             notifyBegin(listener, request);
         }
+    }
 
     private void notifyBegin(Request.BeginListener listener, Request request)
     {
         try
         {
-            if (listener != null)
             listener.onBegin(request);
         }
         catch (Exception x)
@@ -77,17 +97,26 @@ public class RequestNotifier
 
     public void notifyHeaders(Request request)
     {
-        for (Request.HeadersListener listener : request.getRequestListeners(Request.HeadersListener.class))
+        // Optimized to avoid allocations of iterator instances
-            notifyHeaders(listener, request);
+        List<Request.RequestListener> requestListeners = request.getRequestListeners(null);
-        for (Request.Listener listener : client.getRequestListeners())
+        for (int i = 0; i < requestListeners.size(); ++i)
+        {
+            Request.RequestListener listener = requestListeners.get(i);
+            if (listener instanceof Request.HeadersListener)
+                notifyHeaders((Request.HeadersListener)listener, request);
+        }
+        List<Request.Listener> listeners = client.getRequestListeners();
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Request.Listener listener = listeners.get(i);
             notifyHeaders(listener, request);
         }
+    }
 
     private void notifyHeaders(Request.HeadersListener listener, Request request)
     {
         try
         {
-            if (listener != null)
             listener.onHeaders(request);
         }
         catch (Exception x)
@@ -98,17 +127,26 @@ public class RequestNotifier
 
     public void notifyCommit(Request request)
     {
-        for (Request.CommitListener listener : request.getRequestListeners(Request.CommitListener.class))
+        // Optimized to avoid allocations of iterator instances
-            notifyCommit(listener, request);
+        List<Request.RequestListener> requestListeners = request.getRequestListeners(null);
-        for (Request.Listener listener : client.getRequestListeners())
+        for (int i = 0; i < requestListeners.size(); ++i)
+        {
+            Request.RequestListener listener = requestListeners.get(i);
+            if (listener instanceof Request.CommitListener)
+                notifyCommit((Request.CommitListener)listener, request);
+        }
+        List<Request.Listener> listeners = client.getRequestListeners();
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Request.Listener listener = listeners.get(i);
             notifyCommit(listener, request);
         }
+    }
 
     private void notifyCommit(Request.CommitListener listener, Request request)
     {
         try
         {
-            if (listener != null)
             listener.onCommit(request);
         }
         catch (Exception x)
@@ -119,17 +157,26 @@ public class RequestNotifier
 
     public void notifySuccess(Request request)
     {
-        for (Request.SuccessListener listener : request.getRequestListeners(Request.SuccessListener.class))
+        // Optimized to avoid allocations of iterator instances
-            notifySuccess(listener, request);
+        List<Request.RequestListener> requestListeners = request.getRequestListeners(null);
-        for (Request.Listener listener : client.getRequestListeners())
+        for (int i = 0; i < requestListeners.size(); ++i)
+        {
+            Request.RequestListener listener = requestListeners.get(i);
+            if (listener instanceof Request.SuccessListener)
+                notifySuccess((Request.SuccessListener)listener, request);
+        }
+        List<Request.Listener> listeners = client.getRequestListeners();
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Request.Listener listener = listeners.get(i);
             notifySuccess(listener, request);
         }
+    }
 
     private void notifySuccess(Request.SuccessListener listener, Request request)
     {
         try
         {
-            if (listener != null)
             listener.onSuccess(request);
         }
         catch (Exception x)
@@ -140,17 +187,26 @@ public class RequestNotifier
 
     public void notifyFailure(Request request, Throwable failure)
     {
-        for (Request.FailureListener listener : request.getRequestListeners(Request.FailureListener.class))
+        // Optimized to avoid allocations of iterator instances
-            notifyFailure(listener, request, failure);
+        List<Request.RequestListener> requestListeners = request.getRequestListeners(null);
-        for (Request.Listener listener : client.getRequestListeners())
+        for (int i = 0; i < requestListeners.size(); ++i)
+        {
+            Request.RequestListener listener = requestListeners.get(i);
+            if (listener instanceof Request.FailureListener)
+                notifyFailure((Request.FailureListener)listener, request, failure);
+        }
+        List<Request.Listener> listeners = client.getRequestListeners();
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Request.Listener listener = listeners.get(i);
             notifyFailure(listener, request, failure);
         }
+    }
 
     private void notifyFailure(Request.FailureListener listener, Request request, Throwable failure)
     {
         try
         {
-            if (listener != null)
             listener.onFailure(request, failure);
         }
         catch (Exception x)

jetty-client/src/main/java/org/eclipse/jetty/client/ResponseNotifier.java

@@ -42,10 +42,14 @@ public class ResponseNotifier
 
     public void notifyBegin(List<Response.ResponseListener> listeners, Response response)
     {
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.BeginListener)
                 notifyBegin((Response.BeginListener)listener, response);
         }
+    }
 
     private void notifyBegin(Response.BeginListener listener, Response response)
     {
@@ -62,9 +66,13 @@ public class ResponseNotifier
     public boolean notifyHeader(List<Response.ResponseListener> listeners, Response response, HttpField field)
     {
         boolean result = true;
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.HeaderListener)
                 result &= notifyHeader((Response.HeaderListener)listener, response, field);
+        }
         return result;
     }
 
@@ -83,10 +91,14 @@ public class ResponseNotifier
 
     public void notifyHeaders(List<Response.ResponseListener> listeners, Response response)
     {
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.HeadersListener)
                 notifyHeaders((Response.HeadersListener)listener, response);
         }
+    }
 
     private void notifyHeaders(Response.HeadersListener listener, Response response)
     {
@@ -102,10 +114,13 @@ public class ResponseNotifier
 
     public void notifyContent(List<Response.ResponseListener> listeners, Response response, ByteBuffer buffer)
     {
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.ContentListener)
                 notifyContent((Response.ContentListener)listener, response, buffer);
-
+        }
     }
 
     private void notifyContent(Response.ContentListener listener, Response response, ByteBuffer buffer)
@@ -122,10 +137,14 @@ public class ResponseNotifier
 
     public void notifySuccess(List<Response.ResponseListener> listeners, Response response)
     {
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.SuccessListener)
                 notifySuccess((Response.SuccessListener)listener, response);
         }
+    }
 
     private void notifySuccess(Response.SuccessListener listener, Response response)
     {
@@ -141,10 +160,14 @@ public class ResponseNotifier
 
     public void notifyFailure(List<Response.ResponseListener> listeners, Response response, Throwable failure)
     {
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.FailureListener)
                 notifyFailure((Response.FailureListener)listener, response, failure);
         }
+    }
 
     private void notifyFailure(Response.FailureListener listener, Response response, Throwable failure)
     {
@@ -160,10 +183,14 @@ public class ResponseNotifier
 
     public void notifyComplete(List<Response.ResponseListener> listeners, Result result)
     {
-        for (Response.ResponseListener listener : listeners)
+        // Optimized to avoid allocations of iterator instances
+        for (int i = 0; i < listeners.size(); ++i)
+        {
+            Response.ResponseListener listener = listeners.get(i);
             if (listener instanceof Response.CompleteListener)
                 notifyComplete((Response.CompleteListener)listener, result);
         }
+    }
 
     private void notifyComplete(Response.CompleteListener listener, Result result)
     {

jetty-client/src/main/java/org/eclipse/jetty/client/api/Authentication.java

@@ -18,6 +18,8 @@
 
 package org.eclipse.jetty.client.api;
 
+import java.net.URI;
+
 import org.eclipse.jetty.util.Attributes;
 
 /**
@@ -42,7 +44,7 @@ public interface Authentication
      * @param realm the authentication realm as provided in the {@code WWW-Authenticate} response header
      * @return true if this authentication matches, false otherwise
      */
-    boolean matches(String type, String uri, String realm);
+    boolean matches(String type, URI uri, String realm);
 
     /**
      * Executes the authentication mechanism for the given request, returning a {@link Result} that can be
@@ -70,7 +72,7 @@ public interface Authentication
         /**
          * @return the URI of the request that has been used to generate this {@link Result}
          */
-        String getURI();
+        URI getURI();
 
         /**
          * Applies the authentication result to the given request.

jetty-client/src/main/java/org/eclipse/jetty/client/api/AuthenticationStore.java

@@ -18,6 +18,8 @@
 
 package org.eclipse.jetty.client.api;
 
+import java.net.URI;
+
 /**
  * A store for {@link Authentication}s and {@link Authentication.Result}s.
  */
@@ -48,7 +50,7 @@ public interface AuthenticationStore
      * @param realm the authentication realm
      * @return the authentication that matches the given parameters, or null
      */
-    public Authentication findAuthentication(String type, String uri, String realm);
+    public Authentication findAuthentication(String type, URI uri, String realm);
 
     /**
      * @param result the {@link Authentication.Result} to add
@@ -72,5 +74,5 @@ public interface AuthenticationStore
      * @param uri the request URI
      * @return the {@link Authentication.Result} that matches the given URI, or null
      */
-    public Authentication.Result findAuthenticationResult(String uri);
+    public Authentication.Result findAuthenticationResult(URI uri);
 }

jetty-client/src/main/java/org/eclipse/jetty/client/api/Request.java

@@ -19,6 +19,7 @@
 package org.eclipse.jetty.client.api;
 
 import java.io.IOException;
+import java.net.URI;
 import java.nio.file.Path;
 import java.util.EventListener;
 import java.util.List;
@@ -96,7 +97,7 @@ public interface Request
     /**
      * @return the full URI of this request such as "http://host:port/path"
      */
-    String getURI();
+    URI getURI();
 
     /**
      * @return the HTTP version of this request, such as "HTTP/1.1"

jetty-client/src/main/java/org/eclipse/jetty/client/util/BasicAuthentication.java

@@ -18,6 +18,8 @@
 
 package org.eclipse.jetty.client.util;
 
+import java.net.URI;
+
 import org.eclipse.jetty.client.HttpClient;
 import org.eclipse.jetty.client.api.Authentication;
 import org.eclipse.jetty.client.api.AuthenticationStore;
@@ -37,7 +39,7 @@ import org.eclipse.jetty.util.StringUtil;
  */
 public class BasicAuthentication implements Authentication
 {
-    private final String uri;
+    private final URI uri;
     private final String realm;
     private final String user;
     private final String password;
@@ -48,7 +50,7 @@ public class BasicAuthentication implements Authentication
      * @param user the user that wants to authenticate
      * @param password the password of the user
      */
-    public BasicAuthentication(String uri, String realm, String user, String password)
+    public BasicAuthentication(URI uri, String realm, String user, String password)
     {
         this.uri = uri;
         this.realm = realm;
@@ -57,12 +59,12 @@ public class BasicAuthentication implements Authentication
     }
 
     @Override
-    public boolean matches(String type, String uri, String realm)
+    public boolean matches(String type, URI uri, String realm)
     {
         if (!"basic".equalsIgnoreCase(type))
             return false;
 
-        if (!uri.startsWith(this.uri))
+        if (!uri.toString().startsWith(this.uri.toString()))
             return false;
 
         return this.realm.equals(realm);
@@ -78,17 +80,17 @@ public class BasicAuthentication implements Authentication
 
     private static class BasicResult implements Result
     {
-        private final String uri;
+        private final URI uri;
         private final String value;
 
-        public BasicResult(String uri, String value)
+        public BasicResult(URI uri, String value)
         {
             this.uri = uri;
             this.value = value;
         }
 
         @Override
-        public String getURI()
+        public URI getURI()
         {
             return uri;
         }
@@ -96,7 +98,7 @@ public class BasicAuthentication implements Authentication
         @Override
         public void apply(Request request)
         {
-            if (request.getURI().startsWith(uri))
+            if (request.getURI().toString().startsWith(uri.toString()))
                 request.header(HttpHeader.AUTHORIZATION.asString(), value);
         }
 

jetty-client/src/main/java/org/eclipse/jetty/client/util/DigestAuthentication.java

@@ -18,6 +18,7 @@
 
 package org.eclipse.jetty.client.util;
 
+import java.net.URI;
 import java.nio.charset.Charset;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -52,7 +53,7 @@ public class DigestAuthentication implements Authentication
 {
     private static final Pattern PARAM_PATTERN = Pattern.compile("([^=]+)=(.*)");
 
-    private final String uri;
+    private final URI uri;
     private final String realm;
     private final String user;
     private final String password;
@@ -63,7 +64,7 @@ public class DigestAuthentication implements Authentication
      * @param user the user that wants to authenticate
      * @param password the password of the user
      */
-    public DigestAuthentication(String uri, String realm, String user, String password)
+    public DigestAuthentication(URI uri, String realm, String user, String password)
     {
         this.uri = uri;
         this.realm = realm;
@@ -72,12 +73,12 @@ public class DigestAuthentication implements Authentication
     }
 
     @Override
-    public boolean matches(String type, String uri, String realm)
+    public boolean matches(String type, URI uri, String realm)
     {
         if (!"digest".equalsIgnoreCase(type))
             return false;
 
-        if (!uri.startsWith(this.uri))
+        if (!uri.toString().startsWith(this.uri.toString()))
             return false;
 
         return this.realm.equals(realm);
@@ -180,7 +181,7 @@ public class DigestAuthentication implements Authentication
     private class DigestResult implements Result
     {
         private final AtomicInteger nonceCount = new AtomicInteger();
-        private final String uri;
+        private final URI uri;
         private final byte[] content;
         private final String realm;
         private final String user;
@@ -190,7 +191,7 @@ public class DigestAuthentication implements Authentication
         private final String qop;
         private final String opaque;
 
-        public DigestResult(String uri, byte[] content, String realm, String user, String password, String algorithm, String nonce, String qop, String opaque)
+        public DigestResult(URI uri, byte[] content, String realm, String user, String password, String algorithm, String nonce, String qop, String opaque)
         {
             this.uri = uri;
             this.content = content;
@@ -204,7 +205,7 @@ public class DigestAuthentication implements Authentication
         }
 
         @Override
-        public String getURI()
+        public URI getURI()
         {
             return uri;
         }
@@ -212,7 +213,7 @@ public class DigestAuthentication implements Authentication
         @Override
         public void apply(Request request)
         {
-            if (!request.getURI().startsWith(uri))
+            if (!request.getURI().toString().startsWith(uri.toString()))
                 return;
 
             MessageDigest digester = getMessageDigest(algorithm);

jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientAuthenticationTest.java

@@ -20,6 +20,7 @@ package org.eclipse.jetty.client;
 
 import java.io.File;
 import java.io.IOException;
+import java.net.URI;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -34,7 +35,6 @@ import org.eclipse.jetty.client.api.ContentResponse;
 import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.client.util.BasicAuthentication;
 import org.eclipse.jetty.client.util.DigestAuthentication;
-import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.security.Authenticator;
 import org.eclipse.jetty.security.ConstraintMapping;
 import org.eclipse.jetty.security.ConstraintSecurityHandler;
@@ -99,7 +99,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
     public void test_BasicAuthentication() throws Exception
     {
         startBasic(new EmptyServerHandler());
-        String uri = scheme + "://localhost:" + connector.getLocalPort();
+        URI uri = URI.create(scheme + "://localhost:" + connector.getLocalPort());
         test_Authentication(new BasicAuthentication(uri, realm, "basic", "basic"));
     }
 
@@ -107,7 +107,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
     public void test_DigestAuthentication() throws Exception
     {
         startDigest(new EmptyServerHandler());
-        String uri = scheme + "://localhost:" + connector.getLocalPort();
+        URI uri = URI.create(scheme + "://localhost:" + connector.getLocalPort());
         test_Authentication(new DigestAuthentication(uri, realm, "digest", "digest"));
     }
 
@@ -148,6 +148,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
         client.getRequestListeners().add(requestListener);
 
         // Request with authentication causes a 401 (no previous successful authentication) + 200
+        request = client.newRequest("localhost", connector.getLocalPort()).scheme(scheme).path("/secure");
         response = request.timeout(5, TimeUnit.SECONDS).send();
         Assert.assertNotNull(response);
         Assert.assertEquals(200, response.getStatus());
@@ -167,7 +168,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
 
         // Further requests do not trigger 401 because there is a previous successful authentication
         // Remove existing header to be sure it's added by the implementation
-        request.header(HttpHeader.AUTHORIZATION.asString(), null);
+        request = client.newRequest("localhost", connector.getLocalPort()).scheme(scheme).path("/secure");
         response = request.timeout(5, TimeUnit.SECONDS).send();
         Assert.assertNotNull(response);
         Assert.assertEquals(200, response.getStatus());
@@ -191,7 +192,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
             }
         });
 
-        String uri = scheme + "://localhost:" + connector.getLocalPort();
+        URI uri = URI.create(scheme + "://localhost:" + connector.getLocalPort());
         client.getAuthenticationStore().addAuthentication(new BasicAuthentication(uri, realm, "basic", "basic"));
 
         final CountDownLatch requests = new CountDownLatch(3);
@@ -230,7 +231,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
             }
         });
 
-        String uri = scheme + "://localhost:" + connector.getLocalPort();
+        URI uri = URI.create(scheme + "://localhost:" + connector.getLocalPort());
         client.getAuthenticationStore().addAuthentication(new BasicAuthentication(uri, realm, "basic", "basic"));
 
         final CountDownLatch requests = new CountDownLatch(3);
@@ -272,7 +273,7 @@ public class HttpClientAuthenticationTest extends AbstractHttpClientServerTest
         client.getRequestListeners().add(requestListener);
 
         AuthenticationStore authenticationStore = client.getAuthenticationStore();
-        String uri = scheme + "://localhost:" + connector.getLocalPort();
+        URI uri = URI.create(scheme + "://localhost:" + connector.getLocalPort());
         BasicAuthentication authentication = new BasicAuthentication(uri, realm, "basic", "basic");
         authenticationStore.addAuthentication(authentication);
 

jetty-client/src/test/java/org/eclipse/jetty/client/HttpClientLoadTest.java

@@ -19,6 +19,7 @@
 package org.eclipse.jetty.client;
 
 import java.io.IOException;
+import java.net.URI;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -113,13 +114,14 @@ public class HttpClientLoadTest extends AbstractHttpClientServerTest
         Assert.assertTrue(failures.toString(), failures.isEmpty());
     }
 
-    private void test(Random random, final CountDownLatch latch, final List<String> failures)
+    private void test(Random random, final CountDownLatch latch, final List<String> failures) throws InterruptedException
     {
         int maxContentLength = 64 * 1024;
 
         // Choose a random destination
         String host = random.nextBoolean() ? "localhost" : "127.0.0.1";
-        Request request = client.newRequest(host, connector.getLocalPort()).scheme(scheme);
+        URI uri = URI.create(scheme + "://" + host + ":" + connector.getLocalPort());
+        Request request = client.newRequest(uri);
 
         // Choose a random method
         HttpMethod method = random.nextBoolean() ? HttpMethod.GET : HttpMethod.POST;
@@ -147,6 +149,7 @@ public class HttpClientLoadTest extends AbstractHttpClientServerTest
                 break;
         }
 
+        final CountDownLatch requestLatch = new CountDownLatch(1);
         request.send(new Response.Listener.Empty()
         {
             private final AtomicInteger contentLength = new AtomicInteger();
@@ -175,9 +178,11 @@ public class HttpClientLoadTest extends AbstractHttpClientServerTest
                 }
                 if (contentLength.get() != 0)
                     failures.add("Content length mismatch " + contentLength);
+                requestLatch.countDown();
                 latch.countDown();
             }
         });
+        requestLatch.await(5, TimeUnit.SECONDS);
     }
 
     private class LoadHandler extends AbstractHandler

jetty-client/src/test/java/org/eclipse/jetty/client/api/Usage.java

@@ -192,7 +192,7 @@ public class Usage
         HttpClient client = new HttpClient();
         client.start();
 
-        String uri = "http://localhost:8080/secure";
+        URI uri = URI.create("http://localhost:8080/secure");
 
         // Setup Basic authentication credentials for TestRealm
         client.getAuthenticationStore().addAuthentication(new BasicAuthentication(uri, "TestRealm", "username", "password"));

tests/test-loginservice/src/test/java/org/eclipse/jetty/JdbcLoginServiceTest.java

@@ -25,6 +25,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.URI;
 import java.net.URLDecoder;
 import java.sql.Connection;
 import java.sql.DriverManager;
@@ -301,7 +302,7 @@ public class JdbcLoginServiceTest
          executor.setName(executor.getName() + "-client");
          _client.setExecutor(executor);
          AuthenticationStore authStore = _client.getAuthenticationStore();
-         authStore.addAuthentication(new BasicAuthentication(_baseUrl, __realm, "jetty", "jetty"));
+         authStore.addAuthentication(new BasicAuthentication(URI.create(_baseUrl), __realm, "jetty", "jetty"));
          _client.start();
      }