1 /*
   2  * Copyright (c) 2015, 2016, 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;
  27 
  28 import java.io.IOException;
  29 import java.util.concurrent.CompletableFuture;
  30 import java.util.concurrent.Executor;
  31 import jdk.incubator.http.internal.common.MinimalFuture;
  32 import static jdk.incubator.http.HttpClient.Version.HTTP_1_1;
  33 
  34 /**
  35  * Splits request so that headers and body can be sent separately with optional
  36  * (multiple) responses in between (e.g. 100 Continue). Also request and
  37  * response always sent/received in different calls.
  38  *
  39  * Synchronous and asynchronous versions of each method are provided.
  40  *
  41  * Separate implementations of this class exist for HTTP/1.1 and HTTP/2
  42  *      Http1Exchange   (HTTP/1.1)
  43  *      Stream          (HTTP/2)
  44  *
  45  * These implementation classes are where work is allocated to threads.
  46  */
  47 abstract class ExchangeImpl<T> {
  48 
  49     final Exchange<T> exchange;
  50 
  51     ExchangeImpl(Exchange<T> e) {
  52         // e == null means a http/2 pushed stream
  53         this.exchange = e;
  54     }
  55 
  56     final Exchange<T> getExchange() {
  57         return exchange;
  58     }
  59 
  60 
  61     /**
  62      * Returns the {@link HttpConnection} instance to which this exchange is
  63      * assigned.
  64      */
  65     abstract HttpConnection connection();
  66 
  67     /**
  68      * Initiates a new exchange and assigns it to a connection if one exists
  69      * already. connection usually null.
  70      */
  71     static <U> ExchangeImpl<U> get(Exchange<U> exchange, HttpConnection connection)
  72         throws IOException, InterruptedException
  73     {
  74         HttpRequestImpl req = exchange.request();
  75         if (exchange.version() == HTTP_1_1) {
  76             return new Http1Exchange<>(exchange, connection);
  77         } else {
  78             Http2ClientImpl c2 = exchange.client().client2(); // TODO: improve
  79             HttpRequestImpl request = exchange.request();
  80             Http2Connection c;
  81             try {
  82                 c = c2.getConnectionFor(request);
  83             } catch (Http2Connection.ALPNException e) {
  84                 // failed to negotiate "h2"
  85                 AbstractAsyncSSLConnection as = e.getConnection();
  86                 as.stopAsyncReading();
  87                 HttpConnection sslc = as.downgrade();
  88                 ExchangeImpl<U> ex = new Http1Exchange<>(exchange, sslc);
  89                 return ex;
  90             }
  91             if (c == null) {
  92                 // no existing connection. Send request with HTTP 1 and then
  93                 // upgrade if successful
  94                 ExchangeImpl<U> ex = new Http1Exchange<>(exchange, connection);
  95                 exchange.h2Upgrade();
  96                 return ex;
  97             }
  98             return c.createStream(exchange);
  99         }
 100     }
 101 
 102     /* The following methods have separate HTTP/1.1 and HTTP/2 implementations */
 103 
 104     /**
 105      * Sends the request headers only. May block until all sent.
 106      */
 107     abstract void sendHeadersOnly() throws IOException, InterruptedException;
 108 
 109     // Blocking impl but in async style
 110 
 111     CompletableFuture<ExchangeImpl<T>> sendHeadersAsync() {
 112         // this is blocking. cf will already be completed.
 113         return MinimalFuture.supply(() -> {
 114             sendHeadersOnly();
 115             return this;
 116         });
 117     }
 118 
 119     /**
 120      * Gets response by blocking if necessary. This may be an
 121      * intermediate response (like 101) or a final response 200 etc. Returns
 122      * before body is read.
 123      */
 124     abstract Response getResponse() throws IOException;
 125 
 126     abstract T readBody(HttpResponse.BodyHandler<T> handler,
 127                         boolean returnConnectionToPool) throws IOException;
 128 
 129     abstract CompletableFuture<T> readBodyAsync(HttpResponse.BodyHandler<T> handler,
 130                                                 boolean returnConnectionToPool,
 131                                                 Executor executor);
 132 
 133     /**
 134      * Async version of getResponse. Completes before body is read.
 135      */
 136     abstract CompletableFuture<Response> getResponseAsync(Executor executor);
 137 
 138     /**
 139      * Sends a request body after request headers.
 140      */
 141     abstract void sendBody() throws IOException, InterruptedException;
 142 
 143     // Async version of sendBody(). This only used when body sent separately
 144     // to headers (100 continue)
 145     CompletableFuture<ExchangeImpl<T>> sendBodyAsync() {
 146         return MinimalFuture.supply(() -> {
 147             sendBody();
 148             return this;
 149         });
 150     }
 151 
 152     /**
 153      * Cancels a request.  Not currently exposed through API.
 154      */
 155     abstract void cancel();
 156 
 157     /**
 158      * Cancels a request with a cause.  Not currently exposed through API.
 159      */
 160     abstract void cancel(IOException cause);
 161 }