http-client-branch: move BufferingSubscriber to internal http-client-branch
authorchegar
Tue, 06 Feb 2018 10:34:47 +0000
branchhttp-client-branch
changeset 56075 c76699d2e572
parent 56074 06459c34105f
child 56076 9a2855e0a796
http-client-branch: move BufferingSubscriber to internal
src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/BufferingSubscriber.java
src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/HttpResponse.java
src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/BufferingSubscriber.java
--- a/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/BufferingSubscriber.java	Mon Feb 05 19:12:00 2018 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,314 +0,0 @@
-/*
- * Copyright (c) 2017, 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 jdk.incubator.http;
-
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.ListIterator;
-import java.util.Objects;
-import java.util.concurrent.CompletionStage;
-import java.util.concurrent.Flow;
-import java.util.concurrent.atomic.AtomicBoolean;
-import jdk.incubator.http.internal.common.Demand;
-import jdk.incubator.http.internal.common.SequentialScheduler;
-import jdk.incubator.http.internal.common.Utils;
-
-/**
- * A buffering BodySubscriber. When subscribed, accumulates ( buffers ) a given
- * amount ( in bytes ) of a publisher's data before pushing it to a downstream
- * subscriber.
- */
-class BufferingSubscriber<T> implements HttpResponse.BodySubscriber<T>
-{
-    /** The downstream consumer of the data. */
-    private final HttpResponse.BodySubscriber<T> downstreamSubscriber;
-    /** The amount of data to be accumulate before pushing downstream. */
-    private final int bufferSize;
-
-    /** The subscription, created lazily. */
-    private volatile Flow.Subscription subscription;
-    /** The downstream subscription, created lazily. */
-    private volatile DownstreamSubscription downstreamSubscription;
-
-    /** Must be held when accessing the internal buffers. */
-    private final Object buffersLock = new Object();
-    /** The internal buffers holding the buffered data. */
-    private ArrayList<ByteBuffer> internalBuffers;
-    /** The actual accumulated remaining bytes in internalBuffers. */
-    private int accumulatedBytes;
-
-    /** Holds the Throwable from upstream's onError. */
-    private volatile Throwable throwable;
-
-    /** State of the buffering subscriber:
-     *  1) [UNSUBSCRIBED] when initially created
-     *  2) [ACTIVE] when subscribed and can receive data
-     *  3) [ERROR | CANCELLED | COMPLETE] (terminal state)
-     */
-    static final int UNSUBSCRIBED = 0x01;
-    static final int ACTIVE       = 0x02;
-    static final int ERROR        = 0x04;
-    static final int CANCELLED    = 0x08;
-    static final int COMPLETE     = 0x10;
-
-    private volatile int state;
-
-    BufferingSubscriber(HttpResponse.BodySubscriber<T> downstreamSubscriber,
-                        int bufferSize) {
-        this.downstreamSubscriber = Objects.requireNonNull(downstreamSubscriber);
-        this.bufferSize = bufferSize;
-        synchronized (buffersLock) {
-            internalBuffers = new ArrayList<>();
-        }
-        state = UNSUBSCRIBED;
-    }
-
-    /** Returns the number of bytes remaining in the given buffers. */
-    private static final long remaining(List<ByteBuffer> buffers) {
-        return buffers.stream().mapToLong(ByteBuffer::remaining).sum();
-    }
-
-    /**
-     * Tells whether, or not, there is at least a sufficient number of bytes
-     * accumulated in the internal buffers. If the subscriber is COMPLETE, and
-     * has some buffered data, then there is always enough ( to pass downstream ).
-     */
-    private final boolean hasEnoughAccumulatedBytes() {
-        assert Thread.holdsLock(buffersLock);
-        return accumulatedBytes >= bufferSize
-                || (state == COMPLETE && accumulatedBytes > 0);
-    }
-
-    /**
-     * Returns a new, unmodifiable, List<ByteBuffer> containing exactly the
-     * amount of data as required before pushing downstream. The amount of data
-     * may be less than required ( bufferSize ), in the case where the subscriber
-     * is COMPLETE.
-     */
-    private List<ByteBuffer> fromInternalBuffers() {
-        assert Thread.holdsLock(buffersLock);
-        int leftToFill = bufferSize;
-        int state = this.state;
-        assert (state == ACTIVE || state == CANCELLED)
-                ? accumulatedBytes >= leftToFill : true;
-        List<ByteBuffer> dsts = new ArrayList<>();
-
-        ListIterator<ByteBuffer> itr = internalBuffers.listIterator();
-        while (itr.hasNext()) {
-            ByteBuffer b = itr.next();
-            if (b.remaining() <= leftToFill) {
-                itr.remove();
-                if (b.position() != 0)
-                    b = b.slice();  // ensure position = 0 when propagated
-                dsts.add(b);
-                leftToFill -= b.remaining();
-                accumulatedBytes -= b.remaining();
-                if (leftToFill == 0)
-                    break;
-            } else {
-                int prevLimit = b.limit();
-                b.limit(b.position() + leftToFill);
-                ByteBuffer slice = b.slice();
-                dsts.add(slice);
-                b.limit(prevLimit);
-                b.position(b.position() + leftToFill);
-                accumulatedBytes -= leftToFill;
-                leftToFill = 0;
-                break;
-            }
-        }
-        assert (state == ACTIVE || state == CANCELLED)
-                ? leftToFill == 0 : state == COMPLETE;
-        assert (state == ACTIVE || state == CANCELLED)
-                ? remaining(dsts) == bufferSize : state == COMPLETE;
-        assert accumulatedBytes >= 0;
-        assert dsts.stream().noneMatch(b -> b.position() != 0);
-        return Collections.unmodifiableList(dsts);
-    }
-
-    /** Subscription that is passed to the downstream subscriber. */
-    private class DownstreamSubscription implements Flow.Subscription {
-        private final AtomicBoolean cancelled = new AtomicBoolean(); // false
-        private final Demand demand = new Demand();
-        private volatile boolean illegalArg;
-
-        @Override
-        public void request(long n) {
-            if (cancelled.get() || illegalArg) {
-                return;
-            }
-            if (n <= 0L) {
-                // pass the "bad" value upstream so the Publisher can deal with
-                // it appropriately, i.e. invoke onError
-                illegalArg = true;
-                subscription.request(n);
-                return;
-            }
-
-            demand.increase(n);
-
-            pushDemanded();
-        }
-
-        private final SequentialScheduler pushDemandedScheduler =
-                new SequentialScheduler(new PushDemandedTask());
-
-        void pushDemanded() {
-            if (cancelled.get())
-                return;
-            pushDemandedScheduler.runOrSchedule();
-        }
-
-        class PushDemandedTask extends SequentialScheduler.CompleteRestartableTask {
-            @Override
-            public void run() {
-                try {
-                    Throwable t = throwable;
-                    if (t != null) {
-                        pushDemandedScheduler.stop(); // stop the demand scheduler
-                        downstreamSubscriber.onError(t);
-                        return;
-                    }
-
-                    while (true) {
-                        List<ByteBuffer> item;
-                        synchronized (buffersLock) {
-                            if (cancelled.get())
-                                return;
-                            if (!hasEnoughAccumulatedBytes())
-                                break;
-                            if (!demand.tryDecrement())
-                                break;
-                            item = fromInternalBuffers();
-                        }
-                        assert item != null;
-
-                        downstreamSubscriber.onNext(item);
-                    }
-                    if (cancelled.get())
-                        return;
-
-                    // complete only if all data consumed
-                    boolean complete;
-                    synchronized (buffersLock) {
-                        complete = state == COMPLETE && internalBuffers.isEmpty();
-                    }
-                    if (complete) {
-                        assert internalBuffers.isEmpty();
-                        pushDemandedScheduler.stop(); // stop the demand scheduler
-                        downstreamSubscriber.onComplete();
-                        return;
-                    }
-                } catch (Throwable t) {
-                    cancel();  // cancel if there is any error
-                    throw t;
-                }
-
-                boolean requestMore = false;
-                synchronized (buffersLock) {
-                    if (!hasEnoughAccumulatedBytes() && !demand.isFulfilled()) {
-                        // request more upstream data
-                        requestMore = true;
-                    }
-                }
-                if (requestMore)
-                    subscription.request(1);
-            }
-        }
-
-        @Override
-        public void cancel() {
-            if (cancelled.compareAndExchange(false, true))
-                return;  // already cancelled
-
-            state = CANCELLED;  // set CANCELLED state of upstream subscriber
-            subscription.cancel();  // cancel upstream subscription
-            pushDemandedScheduler.stop(); // stop the demand scheduler
-        }
-    }
-
-    @Override
-    public void onSubscribe(Flow.Subscription subscription) {
-        Objects.requireNonNull(subscription);
-        if (this.subscription != null) {
-            subscription.cancel();
-            return;
-        }
-
-        int s = this.state;
-        assert s == UNSUBSCRIBED;
-        state = ACTIVE;
-        this.subscription = subscription;
-        downstreamSubscription = new DownstreamSubscription();
-        downstreamSubscriber.onSubscribe(downstreamSubscription);
-    }
-
-    @Override
-    public void onNext(List<ByteBuffer> item) {
-        Objects.requireNonNull(item);
-
-        int s = state;
-        if (s == CANCELLED)
-            return;
-
-        if (s != ACTIVE)
-            throw new InternalError("onNext on inactive subscriber");
-
-        synchronized (buffersLock) {
-            internalBuffers.addAll(item);
-            accumulatedBytes += remaining(item);
-        }
-
-        downstreamSubscription.pushDemanded();
-    }
-
-    @Override
-    public void onError(Throwable incomingThrowable) {
-        Objects.requireNonNull(incomingThrowable);
-        int s = state;
-        assert s == ACTIVE : "Expected ACTIVE, got:" + s;
-        state = ERROR;
-        Throwable t = this.throwable;
-        assert t == null : "Expected null, got:" + t;
-        this.throwable = incomingThrowable;
-        downstreamSubscription.pushDemanded();
-    }
-
-    @Override
-    public void onComplete() {
-        int s = state;
-        assert s == ACTIVE : "Expected ACTIVE, got:" + s;
-        state = COMPLETE;
-        downstreamSubscription.pushDemanded();
-    }
-
-    @Override
-    public CompletionStage<T> getBody() {
-        return downstreamSubscriber.getBody();
-    }
-}
--- a/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/HttpResponse.java	Mon Feb 05 19:12:00 2018 +0000
+++ b/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/HttpResponse.java	Tue Feb 06 10:34:47 2018 +0000
@@ -25,13 +25,10 @@
 
 package jdk.incubator.http;
 
-import jdk.incubator.http.internal.common.MinimalFuture;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URI;
-import static jdk.incubator.http.internal.common.Utils.unchecked;
-import static jdk.incubator.http.internal.common.Utils.charsetFrom;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.nio.channels.FileChannel;
@@ -54,6 +51,9 @@
 import java.util.function.Function;
 import java.util.stream.Stream;
 import javax.net.ssl.SSLParameters;
+import jdk.incubator.http.internal.BufferingSubscriber;
+import static jdk.incubator.http.internal.common.Utils.unchecked;
+import static jdk.incubator.http.internal.common.Utils.charsetFrom;
 
 /**
  * Represents a response to a {@link HttpRequest}.
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/BufferingSubscriber.java	Tue Feb 06 10:34:47 2018 +0000
@@ -0,0 +1,315 @@
+/*
+ * Copyright (c) 2017, 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 jdk.incubator.http.internal;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Objects;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.Flow;
+import java.util.concurrent.atomic.AtomicBoolean;
+import jdk.incubator.http.HttpResponse.BodySubscriber;
+import jdk.incubator.http.internal.common.Demand;
+import jdk.incubator.http.internal.common.SequentialScheduler;
+import jdk.incubator.http.internal.common.Utils;
+
+/**
+ * A buffering BodySubscriber. When subscribed, accumulates ( buffers ) a given
+ * amount ( in bytes ) of a publisher's data before pushing it to a downstream
+ * subscriber.
+ */
+public class BufferingSubscriber<T> implements BodySubscriber<T>
+{
+    /** The downstream consumer of the data. */
+    private final BodySubscriber<T> downstreamSubscriber;
+    /** The amount of data to be accumulate before pushing downstream. */
+    private final int bufferSize;
+
+    /** The subscription, created lazily. */
+    private volatile Flow.Subscription subscription;
+    /** The downstream subscription, created lazily. */
+    private volatile DownstreamSubscription downstreamSubscription;
+
+    /** Must be held when accessing the internal buffers. */
+    private final Object buffersLock = new Object();
+    /** The internal buffers holding the buffered data. */
+    private ArrayList<ByteBuffer> internalBuffers;
+    /** The actual accumulated remaining bytes in internalBuffers. */
+    private int accumulatedBytes;
+
+    /** Holds the Throwable from upstream's onError. */
+    private volatile Throwable throwable;
+
+    /** State of the buffering subscriber:
+     *  1) [UNSUBSCRIBED] when initially created
+     *  2) [ACTIVE] when subscribed and can receive data
+     *  3) [ERROR | CANCELLED | COMPLETE] (terminal state)
+     */
+    static final int UNSUBSCRIBED = 0x01;
+    static final int ACTIVE       = 0x02;
+    static final int ERROR        = 0x04;
+    static final int CANCELLED    = 0x08;
+    static final int COMPLETE     = 0x10;
+
+    private volatile int state;
+
+    public BufferingSubscriber(BodySubscriber<T> downstreamSubscriber,
+                               int bufferSize) {
+        this.downstreamSubscriber = Objects.requireNonNull(downstreamSubscriber);
+        this.bufferSize = bufferSize;
+        synchronized (buffersLock) {
+            internalBuffers = new ArrayList<>();
+        }
+        state = UNSUBSCRIBED;
+    }
+
+    /** Returns the number of bytes remaining in the given buffers. */
+    private static final long remaining(List<ByteBuffer> buffers) {
+        return buffers.stream().mapToLong(ByteBuffer::remaining).sum();
+    }
+
+    /**
+     * Tells whether, or not, there is at least a sufficient number of bytes
+     * accumulated in the internal buffers. If the subscriber is COMPLETE, and
+     * has some buffered data, then there is always enough ( to pass downstream ).
+     */
+    private final boolean hasEnoughAccumulatedBytes() {
+        assert Thread.holdsLock(buffersLock);
+        return accumulatedBytes >= bufferSize
+                || (state == COMPLETE && accumulatedBytes > 0);
+    }
+
+    /**
+     * Returns a new, unmodifiable, List<ByteBuffer> containing exactly the
+     * amount of data as required before pushing downstream. The amount of data
+     * may be less than required ( bufferSize ), in the case where the subscriber
+     * is COMPLETE.
+     */
+    private List<ByteBuffer> fromInternalBuffers() {
+        assert Thread.holdsLock(buffersLock);
+        int leftToFill = bufferSize;
+        int state = this.state;
+        assert (state == ACTIVE || state == CANCELLED)
+                ? accumulatedBytes >= leftToFill : true;
+        List<ByteBuffer> dsts = new ArrayList<>();
+
+        ListIterator<ByteBuffer> itr = internalBuffers.listIterator();
+        while (itr.hasNext()) {
+            ByteBuffer b = itr.next();
+            if (b.remaining() <= leftToFill) {
+                itr.remove();
+                if (b.position() != 0)
+                    b = b.slice();  // ensure position = 0 when propagated
+                dsts.add(b);
+                leftToFill -= b.remaining();
+                accumulatedBytes -= b.remaining();
+                if (leftToFill == 0)
+                    break;
+            } else {
+                int prevLimit = b.limit();
+                b.limit(b.position() + leftToFill);
+                ByteBuffer slice = b.slice();
+                dsts.add(slice);
+                b.limit(prevLimit);
+                b.position(b.position() + leftToFill);
+                accumulatedBytes -= leftToFill;
+                leftToFill = 0;
+                break;
+            }
+        }
+        assert (state == ACTIVE || state == CANCELLED)
+                ? leftToFill == 0 : state == COMPLETE;
+        assert (state == ACTIVE || state == CANCELLED)
+                ? remaining(dsts) == bufferSize : state == COMPLETE;
+        assert accumulatedBytes >= 0;
+        assert dsts.stream().noneMatch(b -> b.position() != 0);
+        return Collections.unmodifiableList(dsts);
+    }
+
+    /** Subscription that is passed to the downstream subscriber. */
+    private class DownstreamSubscription implements Flow.Subscription {
+        private final AtomicBoolean cancelled = new AtomicBoolean(); // false
+        private final Demand demand = new Demand();
+        private volatile boolean illegalArg;
+
+        @Override
+        public void request(long n) {
+            if (cancelled.get() || illegalArg) {
+                return;
+            }
+            if (n <= 0L) {
+                // pass the "bad" value upstream so the Publisher can deal with
+                // it appropriately, i.e. invoke onError
+                illegalArg = true;
+                subscription.request(n);
+                return;
+            }
+
+            demand.increase(n);
+
+            pushDemanded();
+        }
+
+        private final SequentialScheduler pushDemandedScheduler =
+                new SequentialScheduler(new PushDemandedTask());
+
+        void pushDemanded() {
+            if (cancelled.get())
+                return;
+            pushDemandedScheduler.runOrSchedule();
+        }
+
+        class PushDemandedTask extends SequentialScheduler.CompleteRestartableTask {
+            @Override
+            public void run() {
+                try {
+                    Throwable t = throwable;
+                    if (t != null) {
+                        pushDemandedScheduler.stop(); // stop the demand scheduler
+                        downstreamSubscriber.onError(t);
+                        return;
+                    }
+
+                    while (true) {
+                        List<ByteBuffer> item;
+                        synchronized (buffersLock) {
+                            if (cancelled.get())
+                                return;
+                            if (!hasEnoughAccumulatedBytes())
+                                break;
+                            if (!demand.tryDecrement())
+                                break;
+                            item = fromInternalBuffers();
+                        }
+                        assert item != null;
+
+                        downstreamSubscriber.onNext(item);
+                    }
+                    if (cancelled.get())
+                        return;
+
+                    // complete only if all data consumed
+                    boolean complete;
+                    synchronized (buffersLock) {
+                        complete = state == COMPLETE && internalBuffers.isEmpty();
+                    }
+                    if (complete) {
+                        assert internalBuffers.isEmpty();
+                        pushDemandedScheduler.stop(); // stop the demand scheduler
+                        downstreamSubscriber.onComplete();
+                        return;
+                    }
+                } catch (Throwable t) {
+                    cancel();  // cancel if there is any error
+                    throw t;
+                }
+
+                boolean requestMore = false;
+                synchronized (buffersLock) {
+                    if (!hasEnoughAccumulatedBytes() && !demand.isFulfilled()) {
+                        // request more upstream data
+                        requestMore = true;
+                    }
+                }
+                if (requestMore)
+                    subscription.request(1);
+            }
+        }
+
+        @Override
+        public void cancel() {
+            if (cancelled.compareAndExchange(false, true))
+                return;  // already cancelled
+
+            state = CANCELLED;  // set CANCELLED state of upstream subscriber
+            subscription.cancel();  // cancel upstream subscription
+            pushDemandedScheduler.stop(); // stop the demand scheduler
+        }
+    }
+
+    @Override
+    public void onSubscribe(Flow.Subscription subscription) {
+        Objects.requireNonNull(subscription);
+        if (this.subscription != null) {
+            subscription.cancel();
+            return;
+        }
+
+        int s = this.state;
+        assert s == UNSUBSCRIBED;
+        state = ACTIVE;
+        this.subscription = subscription;
+        downstreamSubscription = new DownstreamSubscription();
+        downstreamSubscriber.onSubscribe(downstreamSubscription);
+    }
+
+    @Override
+    public void onNext(List<ByteBuffer> item) {
+        Objects.requireNonNull(item);
+
+        int s = state;
+        if (s == CANCELLED)
+            return;
+
+        if (s != ACTIVE)
+            throw new InternalError("onNext on inactive subscriber");
+
+        synchronized (buffersLock) {
+            internalBuffers.addAll(item);
+            accumulatedBytes += remaining(item);
+        }
+
+        downstreamSubscription.pushDemanded();
+    }
+
+    @Override
+    public void onError(Throwable incomingThrowable) {
+        Objects.requireNonNull(incomingThrowable);
+        int s = state;
+        assert s == ACTIVE : "Expected ACTIVE, got:" + s;
+        state = ERROR;
+        Throwable t = this.throwable;
+        assert t == null : "Expected null, got:" + t;
+        this.throwable = incomingThrowable;
+        downstreamSubscription.pushDemanded();
+    }
+
+    @Override
+    public void onComplete() {
+        int s = state;
+        assert s == ACTIVE : "Expected ACTIVE, got:" + s;
+        state = COMPLETE;
+        downstreamSubscription.pushDemanded();
+    }
+
+    @Override
+    public CompletionStage<T> getBody() {
+        return downstreamSubscriber.getBody();
+    }
+}