1 /*

     2  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package jdk.incubator.http.internal;

    27 

    28 import java.lang.System.Logger.Level;

    29 import java.net.InetSocketAddress;

    30 import java.net.URI;

    31 import java.util.Base64;

    32 import java.util.Collections;

    33 import java.util.HashSet;

    34 import java.util.HashMap;

    35 import java.util.Map;

    36 import java.util.Set;

    37 import java.util.concurrent.ConcurrentHashMap;

    38 import java.util.concurrent.CompletableFuture;

    39 

    40 import jdk.incubator.http.internal.common.Log;

    41 import jdk.incubator.http.internal.common.MinimalFuture;

    42 import jdk.incubator.http.internal.common.Utils;

    43 import jdk.incubator.http.internal.frame.SettingsFrame;

    44 import static jdk.incubator.http.internal.frame.SettingsFrame.INITIAL_WINDOW_SIZE;

    45 import static jdk.incubator.http.internal.frame.SettingsFrame.ENABLE_PUSH;

    46 import static jdk.incubator.http.internal.frame.SettingsFrame.HEADER_TABLE_SIZE;

    47 import static jdk.incubator.http.internal.frame.SettingsFrame.MAX_CONCURRENT_STREAMS;

    48 import static jdk.incubator.http.internal.frame.SettingsFrame.MAX_FRAME_SIZE;

    49 

    50 /**

    51  *  Http2 specific aspects of HttpClientImpl

    52  */

    53 class Http2ClientImpl {

    54 

    55     static final boolean DEBUG = Utils.DEBUG; // Revisit: temporary dev flag.

    56     final static System.Logger debug =

    57             Utils.getDebugLogger("Http2ClientImpl"::toString, DEBUG);

    58 

    59     private final HttpClientImpl client;

    60 

    61     Http2ClientImpl(HttpClientImpl client) {

    62         this.client = client;

    63     }

    64 

    65     /* Map key is "scheme:host:port" */

    66     private final Map<String,Http2Connection> connections = new ConcurrentHashMap<>();

    67 

    68     private final Set<String> failures = Collections.synchronizedSet(new HashSet<>());

    69 

    70     /**

    71      * When HTTP/2 requested only. The following describes the aggregate behavior including the

    72      * calling code. In all cases, the HTTP2 connection cache

    73      * is checked first for a suitable connection and that is returned if available.

    74      * If not, a new connection is opened, except in https case when a previous negotiate failed.

    75      * In that case, we want to continue using http/1.1. When a connection is to be opened and

    76      * if multiple requests are sent in parallel then each will open a new connection.

    77      *

    78      * If negotiation/upgrade succeeds then

    79      * one connection will be put in the cache and the others will be closed

    80      * after the initial request completes (not strictly necessary for h2, only for h2c)

    81      *

    82      * If negotiate/upgrade fails, then any opened connections remain open (as http/1.1)

    83      * and will be used and cached in the http/1 cache. Note, this method handles the

    84      * https failure case only (by completing the CF with an ALPN exception, handled externally)

    85      * The h2c upgrade is handled externally also.

    86      *

    87      * Specific CF behavior of this method.

    88      * 1. completes with ALPN exception: h2 negotiate failed for first time. failure recorded.

    89      * 2. completes with other exception: failure not recorded. Caller must handle

    90      * 3. completes normally with null: no connection in cache for h2c or h2 failed previously

    91      * 4. completes normally with connection: h2 or h2c connection in cache. Use it.

    92      */

    93     CompletableFuture<Http2Connection> getConnectionFor(HttpRequestImpl req) {

    94         URI uri = req.uri();

    95         InetSocketAddress proxy = req.proxy();

    96         String key = Http2Connection.keyFor(uri, proxy);

    97 

    98         synchronized (this) {

    99             Http2Connection connection = connections.get(key);

   100             if (connection != null) { // fast path if connection already exists

   101                 return MinimalFuture.completedFuture(connection);

   102             }

   103 

   104             if (!req.secure() || failures.contains(key)) {

   105                 // secure: negotiate failed before. Use http/1.1

   106                 // !secure: no connection available in cache. Attempt upgrade

   107                 return MinimalFuture.completedFuture(null);

   108             }

   109         }

   110         return Http2Connection

   111                 .createAsync(req, this)

   112                 .whenComplete((conn, t) -> {

   113                     synchronized (Http2ClientImpl.this) {

   114                         if (conn != null) {

   115                             offerConnection(conn);

   116                         } else {

   117                             Throwable cause = Utils.getCompletionCause(t);

   118                             if (cause instanceof Http2Connection.ALPNException)

   119                                 failures.add(key);

   120                         }

   121                     }

   122                 });

   123     }

   124 

   125     /*

   126      * Cache the given connection, if no connection to the same

   127      * destination exists. If one exists, then we let the initial stream

   128      * complete but allow it to close itself upon completion.

   129      * This situation should not arise with https because the request

   130      * has not been sent as part of the initial alpn negotiation

   131      */

   132     boolean offerConnection(Http2Connection c) {

   133         String key = c.key();

   134         Http2Connection c1 = connections.putIfAbsent(key, c);

   135         if (c1 != null) {

   136             c.setSingleStream(true);

   137             return false;

   138         }

   139         return true;

   140     }

   141 

   142     void deleteConnection(Http2Connection c) {

   143         connections.remove(c.key());

   144     }

   145 

   146     void stop() {

   147         debug.log(Level.DEBUG, "stopping");

   148         connections.values().forEach(this::close);

   149         connections.clear();

   150     }

   151 

   152     private void close(Http2Connection h2c) {

   153         try { h2c.close(); } catch (Throwable t) {}

   154     }

   155 

   156     HttpClientImpl client() {

   157         return client;

   158     }

   159 

   160     /** Returns the client settings as a base64 (url) encoded string */

   161     String getSettingsString() {

   162         SettingsFrame sf = getClientSettings();

   163         byte[] settings = sf.toByteArray(); // without the header

   164         Base64.Encoder encoder = Base64.getUrlEncoder()

   165                                        .withoutPadding();

   166         return encoder.encodeToString(settings);

   167     }

   168 

   169     private static final int K = 1024;

   170 

   171     private static int getParameter(String property, int min, int max, int defaultValue) {

   172         int value =  Utils.getIntegerNetProperty(property, defaultValue);

   173         // use default value if misconfigured

   174         if (value < min || value > max) {

   175             Log.logError("Property value for {0}={1} not in [{2}..{3}]: " +

   176                     "using default={4}", property, value, min, max, defaultValue);

   177             value = defaultValue;

   178         }

   179         return value;

   180     }

   181 

   182     // used for the connection window, to have a connection window size

   183     // bigger than the initial stream window size.

   184     int getConnectionWindowSize(SettingsFrame clientSettings) {

   185         // Maximum size is 2^31-1. Don't allow window size to be less

   186         // than the stream window size. HTTP/2 specify a default of 64 * K -1,

   187         // but we use 2^26 by default for better performance.

   188         int streamWindow = clientSettings.getParameter(INITIAL_WINDOW_SIZE);

   189 

   190         // The default is the max between the stream window size

   191         // and the connection window size.

   192         int defaultValue = Math.min(Integer.MAX_VALUE,

   193                 Math.max(streamWindow, K*K*32));

   194 

   195         return getParameter(

   196                 "jdk.httpclient.connectionWindowSize",

   197                 streamWindow, Integer.MAX_VALUE, defaultValue);

   198     }

   199 

   200     SettingsFrame getClientSettings() {

   201         SettingsFrame frame = new SettingsFrame();

   202         // default defined for HTTP/2 is 4 K, we use 16 K.

   203         frame.setParameter(HEADER_TABLE_SIZE, getParameter(

   204                 "jdk.httpclient.hpack.maxheadertablesize",

   205                 0, Integer.MAX_VALUE, 16 * K));

   206         // O: does not accept push streams. 1: accepts push streams.

   207         frame.setParameter(ENABLE_PUSH, getParameter(

   208                 "jdk.httpclient.enablepush",

   209                 0, 1, 1));

   210         // HTTP/2 recommends to set the number of concurrent streams

   211         // no lower than 100. We use 100. 0 means no stream would be

   212         // accepted. That would render the client to be non functional,

   213         // so we won't let 0 be configured for our Http2ClientImpl.

   214         frame.setParameter(MAX_CONCURRENT_STREAMS, getParameter(

   215                 "jdk.httpclient.maxstreams",

   216                 1, Integer.MAX_VALUE, 100));

   217         // Maximum size is 2^31-1. Don't allow window size to be less

   218         // than the minimum frame size as this is likely to be a

   219         // configuration error. HTTP/2 specify a default of 64 * K -1,

   220         // but we use 16 M  for better performance.

   221         frame.setParameter(INITIAL_WINDOW_SIZE, getParameter(

   222                 "jdk.httpclient.windowsize",

   223                 16 * K, Integer.MAX_VALUE, 16*K*K));

   224         // HTTP/2 specify a minimum size of 16 K, a maximum size of 2^24-1,

   225         // and a default of 16 K. We use 16 K as default.

   226         frame.setParameter(MAX_FRAME_SIZE, getParameter(

   227                 "jdk.httpclient.maxframesize",

   228                 16 * K, 16 * K * K -1, 16 * K));

   229         return frame;

   230     }

   231 }