--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.net.http/share/classes/jdk/internal/net/http/LineSubscriberAdapter.java Wed Feb 07 21:45:37 2018 +0000
@@ -0,0 +1,467 @@
+/*
+ * Copyright (c) 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.internal.net.http;
+
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CoderResult;
+import java.nio.charset.CodingErrorAction;
+import java.util.List;
+import java.util.Objects;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.ConcurrentLinkedDeque;
+import java.util.concurrent.Flow;
+import java.util.concurrent.Flow.Subscriber;
+import java.util.concurrent.Flow.Subscription;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Function;
+import jdk.internal.net.http.common.Demand;
+import java.net.http.HttpResponse.BodySubscriber;
+import jdk.internal.net.http.common.MinimalFuture;
+import jdk.internal.net.http.common.SequentialScheduler;
+
+/** An adapter between {@code BodySubscriber} and {@code Flow.Subscriber<String>}. */
+public final class LineSubscriberAdapter<S extends Subscriber<? super String>,R>
+ implements BodySubscriber<R> {
+ private final CompletableFuture<R> cf = new MinimalFuture<>();
+ private final S subscriber;
+ private final Function<S, R> finisher;
+ private final Charset charset;
+ private final String eol;
+ private volatile LineSubscription downstream;
+
+ private LineSubscriberAdapter(S subscriber,
+ Function<S, R> finisher,
+ Charset charset,
+ String eol) {
+ if (eol != null && eol.isEmpty())
+ throw new IllegalArgumentException("empty line separator");
+ this.subscriber = Objects.requireNonNull(subscriber);
+ this.finisher = Objects.requireNonNull(finisher);
+ this.charset = Objects.requireNonNull(charset);
+ this.eol = eol;
+ }
+
+ @Override
+ public void onSubscribe(Subscription subscription) {
+ downstream = LineSubscription.create(subscription,
+ charset,
+ eol,
+ subscriber,
+ cf);
+ subscriber.onSubscribe(downstream);
+ }
+
+ @Override
+ public void onNext(List<ByteBuffer> item) {
+ try {
+ downstream.submit(item);
+ } catch (Throwable t) {
+ onError(t);
+ }
+ }
+
+ @Override
+ public void onError(Throwable throwable) {
+ try {
+ downstream.signalError(throwable);
+ } finally {
+ cf.completeExceptionally(throwable);
+ }
+ }
+
+ @Override
+ public void onComplete() {
+ try {
+ downstream.signalComplete();
+ } finally {
+ cf.complete(finisher.apply(subscriber));
+ }
+ }
+
+ @Override
+ public CompletionStage<R> getBody() {
+ return cf;
+ }
+
+ public static <S extends Subscriber<? super String>, R> LineSubscriberAdapter<S, R>
+ create(S subscriber, Function<S, R> finisher, Charset charset, String eol)
+ {
+ if (eol != null && eol.isEmpty())
+ throw new IllegalArgumentException("empty line separator");
+ return new LineSubscriberAdapter<>(Objects.requireNonNull(subscriber),
+ Objects.requireNonNull(finisher),
+ Objects.requireNonNull(charset),
+ eol);
+ }
+
+ static final class LineSubscription implements Flow.Subscription {
+ final Flow.Subscription upstreamSubscription;
+ final CharsetDecoder decoder;
+ final String newline;
+ final Demand downstreamDemand;
+ final ConcurrentLinkedDeque<ByteBuffer> queue;
+ final SequentialScheduler scheduler;
+ final Flow.Subscriber<? super String> upstream;
+ final CompletableFuture<?> cf;
+ private final AtomicReference<Throwable> errorRef = new AtomicReference<>();
+ private final AtomicLong demanded = new AtomicLong();
+ private volatile boolean completed;
+ private volatile boolean cancelled;
+
+ private final char[] chars = new char[1024];
+ private final ByteBuffer leftover = ByteBuffer.wrap(new byte[64]);
+ private final CharBuffer buffer = CharBuffer.wrap(chars);
+ private final StringBuilder builder = new StringBuilder();
+ private int lineCount;
+ private String nextLine;
+
+ private LineSubscription(Flow.Subscription s,
+ CharsetDecoder dec,
+ String separator,
+ Flow.Subscriber<? super String> subscriber,
+ CompletableFuture<?> completion) {
+ downstreamDemand = new Demand();
+ queue = new ConcurrentLinkedDeque<>();
+ upstreamSubscription = Objects.requireNonNull(s);
+ decoder = Objects.requireNonNull(dec);
+ newline = separator;
+ upstream = Objects.requireNonNull(subscriber);
+ cf = Objects.requireNonNull(completion);
+ scheduler = SequentialScheduler.synchronizedScheduler(this::loop);
+ }
+
+ @Override
+ public void request(long n) {
+ if (cancelled) return;
+ if (downstreamDemand.increase(n)) {
+ scheduler.runOrSchedule();
+ }
+ }
+
+ @Override
+ public void cancel() {
+ cancelled = true;
+ upstreamSubscription.cancel();
+ }
+
+ public void submit(List<ByteBuffer> list) {
+ queue.addAll(list);
+ demanded.decrementAndGet();
+ scheduler.runOrSchedule();
+ }
+
+ public void signalComplete() {
+ completed = true;
+ scheduler.runOrSchedule();
+ }
+
+ public void signalError(Throwable error) {
+ if (errorRef.compareAndSet(null,
+ Objects.requireNonNull(error))) {
+ scheduler.runOrSchedule();
+ }
+ }
+
+ // This method looks at whether some bytes where left over (in leftover)
+ // from decoding the previous buffer when the previous buffer was in
+ // underflow. If so, it takes bytes one by one from the new buffer 'in'
+ // and combines them with the leftover bytes until 'in' is exhausted or a
+ // character was produced in 'out', resolving the previous underflow.
+ // Returns true if the buffer is still in underflow, false otherwise.
+ // However, in both situation some chars might have been produced in 'out'.
+ private boolean isUnderFlow(ByteBuffer in, CharBuffer out, boolean endOfInput)
+ throws CharacterCodingException {
+ int limit = leftover.position();
+ if (limit == 0) {
+ // no leftover
+ return false;
+ } else {
+ CoderResult res = null;
+ while (in.hasRemaining()) {
+ leftover.position(limit);
+ leftover.limit(++limit);
+ leftover.put(in.get());
+ leftover.position(0);
+ res = decoder.decode(leftover, out,
+ endOfInput && !in.hasRemaining());
+ int remaining = leftover.remaining();
+ if (remaining > 0) {
+ assert leftover.position() == 0;
+ leftover.position(remaining);
+ } else {
+ leftover.position(0);
+ }
+ leftover.limit(leftover.capacity());
+ if (res.isUnderflow() && remaining > 0 && in.hasRemaining()) {
+ continue;
+ }
+ if (res.isError()) {
+ res.throwException();
+ }
+ assert !res.isOverflow();
+ return false;
+ }
+ return !endOfInput;
+ }
+ }
+
+ // extract characters from start to end and remove them from
+ // the StringBuilder
+ private static String take(StringBuilder b, int start, int end) {
+ assert start == 0;
+ String line;
+ if (end == start) return "";
+ line = b.substring(start, end);
+ b.delete(start, end);
+ return line;
+ }
+
+ // finds end of line, returns -1 if not found, or the position after
+ // the line delimiter if found, removing the delimiter in the process.
+ private static int endOfLine(StringBuilder b, String eol, boolean endOfInput) {
+ int len = b.length();
+ if (eol != null) { // delimiter explicitly specified
+ int i = b.indexOf(eol);
+ if (i >= 0) {
+ // remove the delimiter and returns the position
+ // of the char after it.
+ b.delete(i, i + eol.length());
+ return i;
+ }
+ } else { // no delimiter specified, behaves as BufferedReader::readLine
+ boolean crfound = false;
+ for (int i = 0; i < len; i++) {
+ char c = b.charAt(i);
+ if (c == '\n') {
+ // '\n' or '\r\n' found.
+ // remove the delimiter and returns the position
+ // of the char after it.
+ b.delete(crfound ? i - 1 : i, i + 1);
+ return crfound ? i - 1 : i;
+ } else if (crfound) {
+ // previous char was '\r', c != '\n'
+ assert i != 0;
+ // remove the delimiter and returns the position
+ // of the char after it.
+ b.delete(i - 1, i);
+ return i - 1;
+ }
+ crfound = c == '\r';
+ }
+ if (crfound && endOfInput) {
+ // remove the delimiter and returns the position
+ // of the char after it.
+ b.delete(len - 1, len);
+ return len - 1;
+ }
+ }
+ return endOfInput && len > 0 ? len : -1;
+ }
+
+ // Looks at whether the StringBuilder contains a line.
+ // Returns null if more character are needed.
+ private static String nextLine(StringBuilder b, String eol, boolean endOfInput) {
+ int next = endOfLine(b, eol, endOfInput);
+ return (next > -1) ? take(b, 0, next) : null;
+ }
+
+ // Attempts to read the next line. Returns the next line if
+ // the delimiter was found, null otherwise. The delimiters are
+ // consumed.
+ private String nextLine()
+ throws CharacterCodingException {
+ assert nextLine == null;
+ LINES:
+ while (nextLine == null) {
+ boolean endOfInput = completed && queue.isEmpty();
+ nextLine = nextLine(builder, newline,
+ endOfInput && leftover.position() == 0);
+ if (nextLine != null) return nextLine;
+ ByteBuffer b;
+ BUFFERS:
+ while ((b = queue.peek()) != null) {
+ if (!b.hasRemaining()) {
+ queue.poll();
+ continue BUFFERS;
+ }
+ BYTES:
+ while (b.hasRemaining()) {
+ buffer.position(0);
+ buffer.limit(buffer.capacity());
+ boolean endofInput = completed && queue.size() <= 1;
+ if (isUnderFlow(b, buffer, endofInput)) {
+ assert !b.hasRemaining();
+ if (buffer.position() > 0) {
+ buffer.flip();
+ builder.append(buffer);
+ }
+ continue BUFFERS;
+ }
+ CoderResult res = decoder.decode(b, buffer, endofInput);
+ if (res.isError()) res.throwException();
+ if (buffer.position() > 0) {
+ buffer.flip();
+ builder.append(buffer);
+ continue LINES;
+ }
+ if (res.isUnderflow() && b.hasRemaining()) {
+ //System.out.println("underflow: adding " + b.remaining() + " bytes");
+ leftover.put(b);
+ assert !b.hasRemaining();
+ continue BUFFERS;
+ }
+ }
+ }
+
+ assert queue.isEmpty();
+ if (endOfInput) {
+ // Time to cleanup: there may be some undecoded leftover bytes
+ // We need to flush them out.
+ // The decoder has been configured to replace malformed/unmappable
+ // chars with some replacement, in order to behave like
+ // InputStreamReader.
+ leftover.flip();
+ buffer.position(0);
+ buffer.limit(buffer.capacity());
+
+ // decode() must be called just before flush, even if there
+ // is nothing to decode. We must do this even if leftover
+ // has no remaining bytes.
+ CoderResult res = decoder.decode(leftover, buffer, endOfInput);
+ if (buffer.position() > 0) {
+ buffer.flip();
+ builder.append(buffer);
+ }
+ if (res.isError()) res.throwException();
+
+ // Now call decoder.flush()
+ buffer.position(0);
+ buffer.limit(buffer.capacity());
+ res = decoder.flush(buffer);
+ if (buffer.position() > 0) {
+ buffer.flip();
+ builder.append(buffer);
+ }
+ if (res.isError()) res.throwException();
+
+ // It's possible that we reach here twice - just for the
+ // purpose of checking that no bytes were left over, so
+ // we reset leftover/decoder to make the function reentrant.
+ leftover.position(0);
+ leftover.limit(leftover.capacity());
+ decoder.reset();
+
+ // if some chars were produced then this call will
+ // return them.
+ return nextLine = nextLine(builder, newline, endOfInput);
+ }
+ return null;
+ }
+ return null;
+ }
+
+ // The main sequential scheduler loop.
+ private void loop() {
+ try {
+ while (!cancelled) {
+ Throwable error = errorRef.get();
+ if (error != null) {
+ cancelled = true;
+ scheduler.stop();
+ upstream.onError(error);
+ cf.completeExceptionally(error);
+ return;
+ }
+ if (nextLine == null) nextLine = nextLine();
+ if (nextLine == null) {
+ if (completed) {
+ scheduler.stop();
+ if (leftover.position() != 0) {
+ // Underflow: not all bytes could be
+ // decoded, but no more bytes will be coming.
+ // This should not happen as we should already
+ // have got a MalformedInputException, or
+ // replaced the unmappable chars.
+ errorRef.compareAndSet(null,
+ new IllegalStateException(
+ "premature end of input ("
+ + leftover.position()
+ + " undecoded bytes)"));
+ continue;
+ } else {
+ upstream.onComplete();
+ }
+ return;
+ } else if (demanded.get() == 0
+ && !downstreamDemand.isFulfilled()) {
+ long incr = Math.max(1, downstreamDemand.get());
+ demanded.addAndGet(incr);
+ upstreamSubscription.request(incr);
+ continue;
+ } else return;
+ }
+ assert nextLine != null;
+ assert newline != null && !nextLine.endsWith(newline)
+ || !nextLine.endsWith("\n") || !nextLine.endsWith("\r");
+ if (downstreamDemand.tryDecrement()) {
+ String forward = nextLine;
+ nextLine = null;
+ upstream.onNext(forward);
+ } else return; // no demand: come back later
+ }
+ } catch (Throwable t) {
+ try {
+ upstreamSubscription.cancel();
+ } finally {
+ signalError(t);
+ }
+ }
+ }
+
+ static LineSubscription create(Flow.Subscription s,
+ Charset charset,
+ String lineSeparator,
+ Flow.Subscriber<? super String> upstream,
+ CompletableFuture<?> cf) {
+ return new LineSubscription(Objects.requireNonNull(s),
+ Objects.requireNonNull(charset).newDecoder()
+ // use the same decoder configuration than
+ // java.io.InputStreamReader
+ .onMalformedInput(CodingErrorAction.REPLACE)
+ .onUnmappableCharacter(CodingErrorAction.REPLACE),
+ lineSeparator,
+ Objects.requireNonNull(upstream),
+ Objects.requireNonNull(cf));
+ }
+ }
+}
+