Callbacks for Connection initialization

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/BasicHttpClientConnectionManager.java

@@ -45,6 +45,7 @@
 import org.apache.hc.client5.http.config.TlsConfig;
 import org.apache.hc.client5.http.impl.ConnPoolSupport;
 import org.apache.hc.client5.http.impl.ConnectionShutdownException;
+import org.apache.hc.client5.http.io.ConnectionCallback;
 import org.apache.hc.client5.http.io.ConnectionEndpoint;
 import org.apache.hc.client5.http.io.HttpClientConnectionManager;
 import org.apache.hc.client5.http.io.HttpClientConnectionOperator;
@@ -137,6 +138,20 @@ public BasicHttpClientConnectionManager(
         this.lock = new ReentrantLock();
     }
 
+    /**
+     * @since 5.4
+     */
+    public static BasicHttpClientConnectionManager create(
+            final SchemePortResolver schemePortResolver,
+            final DnsResolver dnsResolver,
+            final Lookup<TlsSocketStrategy> tlsSocketStrategyRegistry,
+            final HttpConnectionFactory<ManagedHttpClientConnection> connFactory,
+            final ConnectionCallback connectionCallback) {
+        return new BasicHttpClientConnectionManager(
+                new DefaultHttpClientConnectionOperator(schemePortResolver, dnsResolver, tlsSocketStrategyRegistry, connectionCallback),
+                connFactory);
+    }
+
     /**
      * @since 5.4
      */
@@ -146,7 +161,7 @@ public static BasicHttpClientConnectionManager create(
             final Lookup<TlsSocketStrategy> tlsSocketStrategyRegistry,
             final HttpConnectionFactory<ManagedHttpClientConnection> connFactory) {
         return new BasicHttpClientConnectionManager(
-                new DefaultHttpClientConnectionOperator(schemePortResolver, dnsResolver, tlsSocketStrategyRegistry),
+                new DefaultHttpClientConnectionOperator(schemePortResolver, dnsResolver, tlsSocketStrategyRegistry, null),
                 connFactory);
     }
 
@@ -157,7 +172,7 @@ public static BasicHttpClientConnectionManager create(
             final Lookup<TlsSocketStrategy> tlsSocketStrategyRegistry,
             final HttpConnectionFactory<ManagedHttpClientConnection> connFactory) {
         return new BasicHttpClientConnectionManager(
-                new DefaultHttpClientConnectionOperator(null, null, tlsSocketStrategyRegistry), connFactory);
+                new DefaultHttpClientConnectionOperator(null, null, tlsSocketStrategyRegistry, null), connFactory);
     }
 
     /**
@@ -166,7 +181,7 @@ public static BasicHttpClientConnectionManager create(
     public static BasicHttpClientConnectionManager create(
             final Lookup<TlsSocketStrategy> tlsSocketStrategyRegistry) {
         return new BasicHttpClientConnectionManager(
-                new DefaultHttpClientConnectionOperator(null, null, tlsSocketStrategyRegistry), null);
+                new DefaultHttpClientConnectionOperator(null, null, tlsSocketStrategyRegistry, null), null);
     }
 
     /**
@@ -205,7 +220,7 @@ public BasicHttpClientConnectionManager() {
         this(new DefaultHttpClientConnectionOperator(null, null,
                 RegistryBuilder.<TlsSocketStrategy>create()
                         .register(URIScheme.HTTPS.id, DefaultClientTlsStrategy.createDefault())
-                        .build()),
+                        .build(), null),
                 null);
     }
 

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/DefaultHttpClientConnectionOperator.java

@@ -44,6 +44,7 @@
 import org.apache.hc.client5.http.UnsupportedSchemeException;
 import org.apache.hc.client5.http.impl.ConnPoolSupport;
 import org.apache.hc.client5.http.impl.DefaultSchemePortResolver;
+import org.apache.hc.client5.http.io.ConnectionCallback;
 import org.apache.hc.client5.http.io.DetachedSocketFactory;
 import org.apache.hc.client5.http.io.HttpClientConnectionOperator;
 import org.apache.hc.client5.http.io.ManagedHttpClientConnection;
@@ -91,6 +92,7 @@ public Socket create(final Proxy socksProxy) throws IOException {
     private final Lookup<TlsSocketStrategy> tlsSocketStrategyLookup;
     private final SchemePortResolver schemePortResolver;
     private final DnsResolver dnsResolver;
+    private final ConnectionCallback connectionCallback;
 
     /**
      * @deprecated Provided for backward compatibility
@@ -111,14 +113,16 @@ public DefaultHttpClientConnectionOperator(
             final DetachedSocketFactory detachedSocketFactory,
             final SchemePortResolver schemePortResolver,
             final DnsResolver dnsResolver,
-            final Lookup<TlsSocketStrategy> tlsSocketStrategyLookup) {
+            final Lookup<TlsSocketStrategy> tlsSocketStrategyLookup,
+            final ConnectionCallback connectionCallback) {
         super();
         this.detachedSocketFactory = Args.notNull(detachedSocketFactory, "Plain socket factory");
         this.tlsSocketStrategyLookup = Args.notNull(tlsSocketStrategyLookup, "Socket factory registry");
         this.schemePortResolver = schemePortResolver != null ? schemePortResolver :
                 DefaultSchemePortResolver.INSTANCE;
         this.dnsResolver = dnsResolver != null ? dnsResolver :
                 SystemDefaultDnsResolver.INSTANCE;
+        this.connectionCallback = connectionCallback;
     }
 
     /**
@@ -129,14 +133,15 @@ public DefaultHttpClientConnectionOperator(
             final Lookup<org.apache.hc.client5.http.socket.ConnectionSocketFactory> socketFactoryRegistry,
             final SchemePortResolver schemePortResolver,
             final DnsResolver dnsResolver) {
-        this(PLAIN_SOCKET_FACTORY, schemePortResolver, dnsResolver, adapt(socketFactoryRegistry));
+        this(PLAIN_SOCKET_FACTORY, schemePortResolver, dnsResolver, adapt(socketFactoryRegistry), null);
     }
 
     public DefaultHttpClientConnectionOperator(
             final SchemePortResolver schemePortResolver,
             final DnsResolver dnsResolver,
-            final Lookup<TlsSocketStrategy> tlsSocketStrategyLookup) {
-        this(PLAIN_SOCKET_FACTORY, schemePortResolver, dnsResolver, tlsSocketStrategyLookup);
+            final Lookup<TlsSocketStrategy> tlsSocketStrategyLookup,
+            final ConnectionCallback connectionCallback) {
+        this(PLAIN_SOCKET_FACTORY, schemePortResolver, dnsResolver, tlsSocketStrategyLookup, connectionCallback);
     }
 
     @Override
@@ -169,12 +174,18 @@ public void connect(
         if (endpointHost.getAddress() != null) {
             remoteAddresses = new InetAddress[] { endpointHost.getAddress() };
         } else {
+            if (connectionCallback != null) {
+                connectionCallback.onBeforeDnsResolve(context);
+            }
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} resolving remote address", endpointHost.getHostName());
             }
 
             remoteAddresses = this.dnsResolver.resolve(endpointHost.getHostName());
 
+            if (connectionCallback != null) {
+                connectionCallback.onAfterDnsResolve(context);
+            }
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} resolved to {}", endpointHost.getHostName(), remoteAddresses == null ? "null" : Arrays.asList(remoteAddresses));
             }
@@ -192,6 +203,9 @@ public void connect(
             final InetAddress address = remoteAddresses[i];
             final boolean last = i == remoteAddresses.length - 1;
             final InetSocketAddress remoteAddress = new InetSocketAddress(address, port);
+            if (connectionCallback != null) {
+                connectionCallback.onBeforeSocketConnect(context, endpointHost);
+            }
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} connecting {}->{} ({})", endpointHost, localAddress, remoteAddress, connectTimeout);
             }
@@ -221,6 +235,9 @@ public void connect(
                 }
                 socket.connect(remoteAddress, TimeValue.isPositive(connectTimeout) ? connectTimeout.toMillisecondsIntBound() : 0);
                 conn.bind(socket);
+                if (connectionCallback != null) {
+                    connectionCallback.onAfterSocketConnect(context, endpointHost);
+                }
                 if (LOG.isDebugEnabled()) {
                     LOG.debug("{} {} connected {}->{}", ConnPoolSupport.getId(conn), endpointHost,
                             conn.getLocalAddress(), conn.getRemoteAddress());
@@ -229,11 +246,20 @@ public void connect(
                 final TlsSocketStrategy tlsSocketStrategy = tlsSocketStrategyLookup != null ? tlsSocketStrategyLookup.lookup(endpointHost.getSchemeName()) : null;
                 if (tlsSocketStrategy != null) {
                     final NamedEndpoint tlsName = endpointName != null ? endpointName : endpointHost;
+                    if (connectionCallback != null) {
+                        connectionCallback.onBeforeTlsHandshake(context, endpointHost);
+                    }
                     if (LOG.isDebugEnabled()) {
                         LOG.debug("{} {} upgrading to TLS", ConnPoolSupport.getId(conn), tlsName);
                     }
                     final Socket upgradedSocket = tlsSocketStrategy.upgrade(socket, tlsName.getHostName(), tlsName.getPort(), attachment, context);
                     conn.bind(upgradedSocket);
+                    if (connectionCallback != null) {
+                        connectionCallback.onAfterTlsHandshake(context, endpointHost);
+                    }
+                    if (LOG.isDebugEnabled()) {
+                        LOG.debug("{} {} upgraded to TLS", ConnPoolSupport.getId(conn), tlsName);
+                    }
                 }
                 return;
             } catch (final RuntimeException ex) {
@@ -278,11 +304,20 @@ public void upgrade(
         final TlsSocketStrategy tlsSocketStrategy = tlsSocketStrategyLookup != null ? tlsSocketStrategyLookup.lookup(newProtocol) : null;
         if (tlsSocketStrategy != null) {
             final NamedEndpoint tlsName = endpointName != null ? endpointName : endpointHost;
+            if (connectionCallback != null) {
+                connectionCallback.onBeforeTlsHandshake(context, endpointHost);
+            }
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} upgrading to TLS {}:{}", ConnPoolSupport.getId(conn), tlsName.getHostName(), tlsName.getPort());
             }
             final SSLSocket upgradedSocket = tlsSocketStrategy.upgrade(socket, tlsName.getHostName(), tlsName.getPort(), attachment, context);
             conn.bind(upgradedSocket);
+            if (connectionCallback != null) {
+                connectionCallback.onAfterTlsHandshake(context, endpointHost);
+            }
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("{} upgraded to TLS {}:{}", ConnPoolSupport.getId(conn), tlsName.getHostName(), tlsName.getPort());
+            }
         } else {
             throw new UnsupportedSchemeException(newProtocol + " protocol is not supported");
         }

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/PoolingHttpClientConnectionManager.java

@@ -123,7 +123,7 @@ public PoolingHttpClientConnectionManager() {
         this(new DefaultHttpClientConnectionOperator(null, null,
                 RegistryBuilder.<TlsSocketStrategy>create()
                     .register(URIScheme.HTTPS.id, DefaultClientTlsStrategy.createDefault())
-                    .build()),
+                    .build(), null),
                 PoolConcurrencyPolicy.STRICT,
                 PoolReusePolicy.LIFO,
                 TimeValue.NEG_ONE_MILLISECOND,

httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/PoolingHttpClientConnectionManagerBuilder.java

@@ -34,6 +34,7 @@
 import org.apache.hc.client5.http.SchemePortResolver;
 import org.apache.hc.client5.http.config.ConnectionConfig;
 import org.apache.hc.client5.http.config.TlsConfig;
+import org.apache.hc.client5.http.io.ConnectionCallback;
 import org.apache.hc.client5.http.io.ManagedHttpClientConnection;
 import org.apache.hc.client5.http.ssl.DefaultClientTlsStrategy;
 import org.apache.hc.client5.http.ssl.TlsSocketStrategy;
@@ -84,6 +85,7 @@ public class PoolingHttpClientConnectionManagerBuilder {
     private Resolver<HttpRoute, SocketConfig> socketConfigResolver;
     private Resolver<HttpRoute, ConnectionConfig> connectionConfigResolver;
     private Resolver<HttpHost, TlsConfig> tlsConfigResolver;
+    private ConnectionCallback connectionCallback;
 
     private boolean systemProperties;
 
@@ -237,6 +239,16 @@ public final PoolingHttpClientConnectionManagerBuilder setTlsConfigResolver(
         return this;
     }
 
+    /**
+     * Assigns {@link ConnectionCallback} instance.
+     *
+     * @since 5.4
+     */
+    public final PoolingHttpClientConnectionManagerBuilder setConnectionCallback(final ConnectionCallback connectionCallback) {
+        this.connectionCallback = connectionCallback;
+        return this;
+    }
+
     /**
      * Sets maximum time to live for persistent connections
      *
@@ -281,7 +293,8 @@ public PoolingHttpClientConnectionManager build() {
                                         (systemProperties ?
                                                 DefaultClientTlsStrategy.createSystemDefault() :
                                                 DefaultClientTlsStrategy.createDefault()))
-                                .build()),
+                                .build(),
+                        connectionCallback),
                 poolConcurrencyPolicy,
                 poolReusePolicy,
                 null,

httpclient5/src/main/java/org/apache/hc/client5/http/io/ConnectionCallback.java

@@ -0,0 +1,52 @@
+/*
+ * ====================================================================
+ * 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.hc.client5.http.io;
+
+import org.apache.hc.core5.http.HttpHost;
+import org.apache.hc.core5.http.protocol.HttpContext;
+
+/**
+ * A callback interface that gets invoked upon different steps of connection initialization.
+ * Useful for measuring duration of initialization steps.
+ *
+ * @since 5.4
+ */
+public interface ConnectionCallback {
+
+    void onBeforeDnsResolve(HttpContext httpContext);
+
+    void onAfterDnsResolve(HttpContext httpContext);
+
+    void onBeforeSocketConnect(HttpContext httpContext, HttpHost endpointHost);
+
+    void onAfterSocketConnect(HttpContext httpContext, HttpHost endpointHost);
+
+    void onBeforeTlsHandshake(HttpContext httpContext, HttpHost endpointHost);
+
+    void onAfterTlsHandshake(HttpContext httpContext, HttpHost endpointHost);
+
+}

httpclient5/src/test/java/org/apache/hc/client5/http/impl/io/TestBasicHttpClientConnectionManager.java

@@ -86,7 +86,7 @@ public class TestBasicHttpClientConnectionManager {
     public void setup() throws Exception {
         MockitoAnnotations.openMocks(this);
         mgr = new BasicHttpClientConnectionManager(new DefaultHttpClientConnectionOperator(
-                detachedSocketFactory, schemePortResolver, dnsResolver, tlsSocketStrategyLookup),
+                detachedSocketFactory, schemePortResolver, dnsResolver, tlsSocketStrategyLookup, null),
                 connFactory);
     }