src/java.net.http/share/classes/java/net/http/internal/Http1Exchange.java
branchhttp-client-branch
changeset 56092 fd85b2bf2b0d
parent 56091 aedd6133e7a0
child 56093 22d94c4a3641
--- a/src/java.net.http/share/classes/java/net/http/internal/Http1Exchange.java	Wed Feb 07 15:46:30 2018 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,616 +0,0 @@
-/*
- * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package java.net.http.internal;
-
-import java.io.IOException;
-import java.lang.System.Logger.Level;
-import java.net.InetSocketAddress;
-import java.net.http.HttpResponse.BodyHandler;
-import java.net.http.HttpResponse.BodySubscriber;
-import java.nio.ByteBuffer;
-import java.util.Objects;
-import java.util.concurrent.CompletableFuture;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.concurrent.ConcurrentLinkedDeque;
-import java.util.concurrent.Executor;
-import java.util.concurrent.Flow;
-import java.net.http.internal.common.Demand;
-import java.net.http.internal.common.Log;
-import java.net.http.internal.common.FlowTube;
-import java.net.http.internal.common.SequentialScheduler;
-import java.net.http.internal.common.MinimalFuture;
-import java.net.http.internal.common.Utils;
-import static java.net.http.HttpClient.Version.HTTP_1_1;
-
-/**
- * Encapsulates one HTTP/1.1 request/response exchange.
- */
-class Http1Exchange<T> extends ExchangeImpl<T> {
-
-    static final boolean DEBUG = Utils.DEBUG; // Revisit: temporary dev flag.
-    final System.Logger  debug = Utils.getDebugLogger(this::dbgString, DEBUG);
-    private static final System.Logger DEBUG_LOGGER =
-            Utils.getDebugLogger("Http1Exchange"::toString, DEBUG);
-
-    final HttpRequestImpl request; // main request
-    final Http1Request requestAction;
-    private volatile Http1Response<T> response;
-    final HttpConnection connection;
-    final HttpClientImpl client;
-    final Executor executor;
-    private final Http1AsyncReceiver asyncReceiver;
-
-    /** Records a possible cancellation raised before any operation
-     * has been initiated, or an error received while sending the request. */
-    private Throwable failed;
-    private final List<CompletableFuture<?>> operations; // used for cancel
-
-    /** Must be held when operating on any internal state or data. */
-    private final Object lock = new Object();
-
-    /** Holds the outgoing data, either the headers or a request body part. Or
-     * an error from the request body publisher. At most there can be ~2 pieces
-     * of outgoing data ( onComplete|onError can be invoked without demand ).*/
-    final ConcurrentLinkedDeque<DataPair> outgoing = new ConcurrentLinkedDeque<>();
-
-    /** The write publisher, responsible for writing the complete request ( both
-     * headers and body ( if any ). */
-    private final Http1Publisher writePublisher = new Http1Publisher();
-
-    /** Completed when the header have been published, or there is an error */
-    private final CompletableFuture<ExchangeImpl<T>> headersSentCF  = new MinimalFuture<>();
-     /** Completed when the body has been published, or there is an error */
-    private final CompletableFuture<ExchangeImpl<T>> bodySentCF = new MinimalFuture<>();
-
-    /** The subscriber to the request's body published. Maybe null. */
-    private volatile Http1BodySubscriber bodySubscriber;
-
-    enum State { INITIAL,
-                 HEADERS,
-                 BODY,
-                 ERROR,          // terminal state
-                 COMPLETING,
-                 COMPLETED }     // terminal state
-
-    private State state = State.INITIAL;
-
-    /** A carrier for either data or an error. Used to carry data, and communicate
-     * errors from the request ( both headers and body ) to the exchange. */
-    static class DataPair {
-        Throwable throwable;
-        List<ByteBuffer> data;
-        DataPair(List<ByteBuffer> data, Throwable throwable){
-            this.data = data;
-            this.throwable = throwable;
-        }
-        @Override
-        public String toString() {
-            return "DataPair [data=" + data + ", throwable=" + throwable + "]";
-        }
-    }
-
-    /** An abstract supertype for HTTP/1.1 body subscribers. There are two
-     * concrete implementations: {@link Http1Request.StreamSubscriber}, and
-     * {@link Http1Request.FixedContentSubscriber}, for receiving chunked and
-     * fixed length bodies, respectively. */
-    static abstract class Http1BodySubscriber implements Flow.Subscriber<ByteBuffer> {
-        protected volatile Flow.Subscription subscription;
-        protected volatile boolean complete;
-
-        /** Final sentinel in the stream of request body. */
-        static final List<ByteBuffer> COMPLETED = List.of(ByteBuffer.allocate(0));
-
-        void request(long n) {
-            DEBUG_LOGGER.log(Level.DEBUG, () ->
-                "Http1BodySubscriber requesting " + n + ", from " + subscription);
-            subscription.request(n);
-        }
-
-        static Http1BodySubscriber completeSubscriber() {
-            return new Http1BodySubscriber() {
-                @Override public void onSubscribe(Flow.Subscription subscription) { error(); }
-                @Override public void onNext(ByteBuffer item) { error(); }
-                @Override public void onError(Throwable throwable) { error(); }
-                @Override public void onComplete() { error(); }
-                private void error() {
-                    throw new InternalError("should not reach here");
-                }
-            };
-        }
-    }
-
-    @Override
-    public String toString() {
-        return "HTTP/1.1 " + request.toString();
-    }
-
-    HttpRequestImpl request() {
-        return request;
-    }
-
-    Http1Exchange(Exchange<T> exchange, HttpConnection connection)
-        throws IOException
-    {
-        super(exchange);
-        this.request = exchange.request();
-        this.client = exchange.client();
-        this.executor = exchange.executor();
-        this.operations = new LinkedList<>();
-        operations.add(headersSentCF);
-        operations.add(bodySentCF);
-        if (connection != null) {
-            this.connection = connection;
-        } else {
-            InetSocketAddress addr = request.getAddress();
-            this.connection = HttpConnection.getConnection(addr, client, request, HTTP_1_1);
-        }
-        this.requestAction = new Http1Request(request, this);
-        this.asyncReceiver = new Http1AsyncReceiver(executor, this);
-        asyncReceiver.subscribe(new InitialErrorReceiver());
-    }
-
-    /** An initial receiver that handles no data, but cancels the request if
-     * it receives an error. Will be replaced when reading response body. */
-    final class InitialErrorReceiver implements Http1AsyncReceiver.Http1AsyncDelegate {
-        volatile AbstractSubscription s;
-        @Override
-        public boolean tryAsyncReceive(ByteBuffer ref) {
-            return false;  // no data has been processed, leave it in the queue
-        }
-
-        @Override
-        public void onReadError(Throwable ex) {
-            cancelImpl(ex);
-        }
-
-        @Override
-        public void onSubscribe(AbstractSubscription s) {
-            this.s = s;
-        }
-
-        public AbstractSubscription subscription() {
-            return s;
-        }
-    }
-
-    @Override
-    HttpConnection connection() {
-        return connection;
-    }
-
-    private void connectFlows(HttpConnection connection) {
-        FlowTube tube =  connection.getConnectionFlow();
-        debug.log(Level.DEBUG, "%s connecting flows", tube);
-
-        // Connect the flow to our Http1TubeSubscriber:
-        //   asyncReceiver.subscriber().
-        tube.connectFlows(writePublisher,
-                          asyncReceiver.subscriber());
-    }
-
-    @Override
-    CompletableFuture<ExchangeImpl<T>> sendHeadersAsync() {
-        // create the response before sending the request headers, so that
-        // the response can set the appropriate receivers.
-        debug.log(Level.DEBUG, "Sending headers only");
-        if (response == null) {
-            response = new Http1Response<>(connection, this, asyncReceiver);
-        }
-
-        debug.log(Level.DEBUG, "response created in advance");
-        // If the first attempt to read something triggers EOF, or
-        // IOException("channel reset by peer"), we're going to retry.
-        // Instruct the asyncReceiver to throw ConnectionExpiredException
-        // to force a retry.
-        asyncReceiver.setRetryOnError(true);
-
-        CompletableFuture<Void> connectCF;
-        if (!connection.connected()) {
-            debug.log(Level.DEBUG, "initiating connect async");
-            connectCF = connection.connectAsync();
-            synchronized (lock) {
-                operations.add(connectCF);
-            }
-        } else {
-            connectCF = new MinimalFuture<>();
-            connectCF.complete(null);
-        }
-
-        return connectCF
-                .thenCompose(unused -> {
-                    CompletableFuture<Void> cf = new MinimalFuture<>();
-                    try {
-                        connectFlows(connection);
-
-                        debug.log(Level.DEBUG, "requestAction.headers");
-                        List<ByteBuffer> data = requestAction.headers();
-                        synchronized (lock) {
-                            state = State.HEADERS;
-                        }
-                        debug.log(Level.DEBUG, "setting outgoing with headers");
-                        assert outgoing.isEmpty() : "Unexpected outgoing:" + outgoing;
-                        appendToOutgoing(data);
-                        cf.complete(null);
-                        return cf;
-                    } catch (Throwable t) {
-                        debug.log(Level.DEBUG, "Failed to send headers: %s", t);
-                        connection.close();
-                        cf.completeExceptionally(t);
-                        return cf;
-                    } })
-                .thenCompose(unused -> headersSentCF);
-    }
-
-    @Override
-    CompletableFuture<ExchangeImpl<T>> sendBodyAsync() {
-        assert headersSentCF.isDone();
-        try {
-            bodySubscriber = requestAction.continueRequest();
-            if (bodySubscriber == null) {
-                bodySubscriber = Http1BodySubscriber.completeSubscriber();
-                appendToOutgoing(Http1BodySubscriber.COMPLETED);
-            } else {
-                bodySubscriber.request(1);  // start
-            }
-        } catch (Throwable t) {
-            connection.close();
-            bodySentCF.completeExceptionally(t);
-        }
-        return bodySentCF;
-    }
-
-    @Override
-    CompletableFuture<Response> getResponseAsync(Executor executor) {
-        CompletableFuture<Response> cf = response.readHeadersAsync(executor);
-        Throwable cause;
-        synchronized (lock) {
-            operations.add(cf);
-            cause = failed;
-            failed = null;
-        }
-
-        if (cause != null) {
-            Log.logTrace("Http1Exchange: request [{0}/timeout={1}ms]"
-                            + "\n\tCompleting exceptionally with {2}\n",
-                         request.uri(),
-                         request.timeout().isPresent() ?
-                            // calling duration.toMillis() can throw an exception.
-                            // this is just debugging, we don't care if it overflows.
-                            (request.timeout().get().getSeconds() * 1000
-                             + request.timeout().get().getNano() / 1000000) : -1,
-                         cause);
-            boolean acknowledged = cf.completeExceptionally(cause);
-            debug.log(Level.DEBUG,
-                      () -> acknowledged
-                            ? ("completed response with " + cause)
-                            : ("response already completed, ignoring " + cause));
-        }
-        return cf;
-    }
-
-    @Override
-    CompletableFuture<T> readBodyAsync(BodyHandler<T> handler,
-                                       boolean returnConnectionToPool,
-                                       Executor executor)
-    {
-        BodySubscriber<T> bs = handler.apply(response.responseCode(),
-                                             response.responseHeaders());
-        CompletableFuture<T> bodyCF = response.readBody(bs,
-                                                        returnConnectionToPool,
-                                                        executor);
-        return bodyCF;
-    }
-
-    @Override
-    CompletableFuture<Void> ignoreBody() {
-        return response.ignoreBody(executor);
-    }
-
-    ByteBuffer drainLeftOverBytes() {
-        synchronized (lock) {
-            asyncReceiver.stop();
-            return asyncReceiver.drain(Utils.EMPTY_BYTEBUFFER);
-        }
-    }
-
-    void released() {
-        Http1Response<T> resp = this.response;
-        if (resp != null) resp.completed();
-        asyncReceiver.clear();
-    }
-
-    void completed() {
-        Http1Response<T> resp = this.response;
-        if (resp != null) resp.completed();
-    }
-
-    /**
-     * Cancel checks to see if request and responseAsync finished already.
-     * If not it closes the connection and completes all pending operations
-     */
-    @Override
-    void cancel() {
-        cancelImpl(new IOException("Request cancelled"));
-    }
-
-    /**
-     * Cancel checks to see if request and responseAsync finished already.
-     * If not it closes the connection and completes all pending operations
-     */
-    @Override
-    void cancel(IOException cause) {
-        cancelImpl(cause);
-    }
-
-    private void cancelImpl(Throwable cause) {
-        LinkedList<CompletableFuture<?>> toComplete = null;
-        int count = 0;
-        synchronized (lock) {
-            if (failed == null)
-                failed = cause;
-            if (requestAction != null && requestAction.finished()
-                    && response != null && response.finished()) {
-                return;
-            }
-            connection.close();   // TODO: ensure non-blocking if holding the lock
-            writePublisher.writeScheduler.stop();
-            if (operations.isEmpty()) {
-                Log.logTrace("Http1Exchange: request [{0}/timeout={1}ms] no pending operation."
-                                + "\n\tCan''t cancel yet with {2}",
-                             request.uri(),
-                             request.timeout().isPresent() ?
-                                // calling duration.toMillis() can throw an exception.
-                                // this is just debugging, we don't care if it overflows.
-                                (request.timeout().get().getSeconds() * 1000
-                                 + request.timeout().get().getNano() / 1000000) : -1,
-                             cause);
-            } else {
-                for (CompletableFuture<?> cf : operations) {
-                    if (!cf.isDone()) {
-                        if (toComplete == null) toComplete = new LinkedList<>();
-                        toComplete.add(cf);
-                        count++;
-                    }
-                }
-                operations.clear();
-            }
-        }
-        Log.logError("Http1Exchange.cancel: count=" + count);
-        if (toComplete != null) {
-            // We might be in the selector thread in case of timeout, when
-            // the SelectorManager calls purgeTimeoutsAndReturnNextDeadline()
-            // There may or may not be other places that reach here
-            // from the SelectorManager thread, so just make sure we
-            // don't complete any CF from within the selector manager
-            // thread.
-            Executor exec = client.isSelectorThread()
-                            ? executor
-                            : this::runInline;
-            while (!toComplete.isEmpty()) {
-                CompletableFuture<?> cf = toComplete.poll();
-                exec.execute(() -> {
-                    if (cf.completeExceptionally(cause)) {
-                        debug.log(Level.DEBUG, "completed cf with %s",
-                                 (Object) cause);
-                    }
-                });
-            }
-        }
-    }
-
-    private void runInline(Runnable run) {
-        assert !client.isSelectorThread();
-        run.run();
-    }
-
-    /** Returns true if this exchange was canceled. */
-    boolean isCanceled() {
-        synchronized (lock) {
-            return failed != null;
-        }
-    }
-
-    /** Returns the cause for which this exchange was canceled, if available. */
-    Throwable getCancelCause() {
-        synchronized (lock) {
-            return failed;
-        }
-    }
-
-    /** Convenience for {@link #appendToOutgoing(DataPair)}, with just a Throwable. */
-    void appendToOutgoing(Throwable throwable) {
-        appendToOutgoing(new DataPair(null, throwable));
-    }
-
-    /** Convenience for {@link #appendToOutgoing(DataPair)}, with just data. */
-    void appendToOutgoing(List<ByteBuffer> item) {
-        appendToOutgoing(new DataPair(item, null));
-    }
-
-    private void appendToOutgoing(DataPair dp) {
-        debug.log(Level.DEBUG, "appending to outgoing " + dp);
-        outgoing.add(dp);
-        writePublisher.writeScheduler.runOrSchedule();
-    }
-
-    /** Tells whether, or not, there is any outgoing data that can be published,
-     * or if there is an error. */
-    private boolean hasOutgoing() {
-        return !outgoing.isEmpty();
-    }
-
-    // Invoked only by the publisher
-    // ALL tasks should execute off the Selector-Manager thread
-    /** Returns the next portion of the HTTP request, or the error. */
-    private DataPair getOutgoing() {
-        final Executor exec = client.theExecutor();
-        final DataPair dp = outgoing.pollFirst();
-
-        if (dp == null)  // publisher has not published anything yet
-            return null;
-
-        synchronized (lock) {
-            if (dp.throwable != null) {
-                state = State.ERROR;
-                exec.execute(() -> {
-                    connection.close();
-                    headersSentCF.completeExceptionally(dp.throwable);
-                    bodySentCF.completeExceptionally(dp.throwable);
-                });
-                return dp;
-            }
-
-            switch (state) {
-                case HEADERS:
-                    state = State.BODY;
-                    // completeAsync, since dependent tasks should run in another thread
-                    debug.log(Level.DEBUG, "initiating completion of headersSentCF");
-                    headersSentCF.completeAsync(() -> this, exec);
-                    break;
-                case BODY:
-                    if (dp.data == Http1BodySubscriber.COMPLETED) {
-                        state = State.COMPLETING;
-                        debug.log(Level.DEBUG, "initiating completion of bodySentCF");
-                        bodySentCF.completeAsync(() -> this, exec);
-                    } else {
-                        debug.log(Level.DEBUG, "requesting more body from the subscriber");
-                        exec.execute(() -> bodySubscriber.request(1));
-                    }
-                    break;
-                case INITIAL:
-                case ERROR:
-                case COMPLETING:
-                case COMPLETED:
-                default:
-                    assert false : "Unexpected state:" + state;
-            }
-
-            return dp;
-        }
-    }
-
-    /** A Publisher of HTTP/1.1 headers and request body. */
-    final class Http1Publisher implements FlowTube.TubePublisher {
-
-        final System.Logger  debug = Utils.getDebugLogger(this::dbgString);
-        volatile Flow.Subscriber<? super List<ByteBuffer>> subscriber;
-        volatile boolean cancelled;
-        final Http1WriteSubscription subscription = new Http1WriteSubscription();
-        final Demand demand = new Demand();
-        final SequentialScheduler writeScheduler =
-                SequentialScheduler.synchronizedScheduler(new WriteTask());
-
-        @Override
-        public void subscribe(Flow.Subscriber<? super List<ByteBuffer>> s) {
-            assert state == State.INITIAL;
-            Objects.requireNonNull(s);
-            assert subscriber == null;
-
-            subscriber = s;
-            debug.log(Level.DEBUG, "got subscriber: %s", s);
-            s.onSubscribe(subscription);
-        }
-
-        volatile String dbgTag;
-        String dbgString() {
-            String tag = dbgTag;
-            Object flow = connection.getConnectionFlow();
-            if (tag == null && flow != null) {
-                dbgTag = tag = "Http1Publisher(" + flow + ")";
-            } else if (tag == null) {
-                tag = "Http1Publisher(?)";
-            }
-            return tag;
-        }
-
-        final class WriteTask implements Runnable {
-            @Override
-            public void run() {
-                assert state != State.COMPLETED : "Unexpected state:" + state;
-                debug.log(Level.DEBUG, "WriteTask");
-                if (subscriber == null) {
-                    debug.log(Level.DEBUG, "no subscriber yet");
-                    return;
-                }
-                debug.log(Level.DEBUG, () -> "hasOutgoing = " + hasOutgoing());
-                while (hasOutgoing() && demand.tryDecrement()) {
-                    DataPair dp = getOutgoing();
-
-                    if (dp.throwable != null) {
-                        debug.log(Level.DEBUG, "onError");
-                        // Do not call the subscriber's onError, it is not required.
-                        writeScheduler.stop();
-                    } else {
-                        List<ByteBuffer> data = dp.data;
-                        if (data == Http1BodySubscriber.COMPLETED) {
-                            synchronized (lock) {
-                                assert state == State.COMPLETING : "Unexpected state:" + state;
-                                state = State.COMPLETED;
-                            }
-                            debug.log(Level.DEBUG,
-                                     "completed, stopping %s", writeScheduler);
-                            writeScheduler.stop();
-                            // Do nothing more. Just do not publish anything further.
-                            // The next Subscriber will eventually take over.
-
-                        } else {
-                            debug.log(Level.DEBUG, () ->
-                                    "onNext with " + Utils.remaining(data) + " bytes");
-                            subscriber.onNext(data);
-                        }
-                    }
-                }
-            }
-        }
-
-        final class Http1WriteSubscription implements Flow.Subscription {
-
-            @Override
-            public void request(long n) {
-                if (cancelled)
-                    return;  //no-op
-                demand.increase(n);
-                debug.log(Level.DEBUG,
-                        "subscription request(%d), demand=%s", n, demand);
-                writeScheduler.runOrSchedule(client.theExecutor());
-            }
-
-            @Override
-            public void cancel() {
-                debug.log(Level.DEBUG, "subscription cancelled");
-                if (cancelled)
-                    return;  //no-op
-                cancelled = true;
-                writeScheduler.stop();
-            }
-        }
-    }
-
-    String dbgString() {
-        return "Http1Exchange";
-    }
-}