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test/java/net/httpclient/HttpInputStreamTest.java
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@@ -30,18 +30,21 @@
import jdk.incubator.http.HttpHeaders;
import jdk.incubator.http.HttpRequest;
import jdk.incubator.http.HttpResponse;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.List;
import java.util.Locale;
import java.util.Optional;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.Flow;
import java.util.stream.Stream;
+import static java.lang.System.err;
/*
* @test
* @summary An example on how to read a response body with InputStream...
* @run main/othervm HttpInputStreamTest
@@ -59,11 +62,11 @@
* the response body is fully received.
*/
public static class HttpInputStreamHandler
implements HttpResponse.BodyHandler<InputStream> {
- public static final int MAX_BUFFERS_IN_QUEUE = 1;
+ public static final int MAX_BUFFERS_IN_QUEUE = 1; // lock-step with the producer
private final int maxBuffers;
public HttpInputStreamHandler() {
this(MAX_BUFFERS_IN_QUEUE);
@@ -84,18 +87,20 @@
*/
private static class HttpResponseInputStream extends InputStream
implements HttpResponse.BodyProcessor<InputStream> {
// An immutable ByteBuffer sentinel to mark that the last byte was received.
- private static final ByteBuffer LAST = ByteBuffer.wrap(new byte[0]);
+ private static final ByteBuffer LAST_BUFFER = ByteBuffer.wrap(new byte[0]);
+ private static final List<ByteBuffer> LAST_LIST = List.of(LAST_BUFFER);
// A queue of yet unprocessed ByteBuffers received from the flow API.
- private final BlockingQueue<ByteBuffer> buffers;
+ private final BlockingQueue<List<ByteBuffer>> buffers;
private volatile Flow.Subscription subscription;
private volatile boolean closed;
private volatile Throwable failed;
- private volatile ByteBuffer current;
+ private volatile List<ByteBuffer> currentList;
+ private volatile ByteBuffer currentBuffer;
HttpResponseInputStream() {
this(MAX_BUFFERS_IN_QUEUE);
}
@@ -117,52 +122,62 @@
// If the current buffer has no remaining data, will take the
// next buffer from the buffers queue, possibly blocking until
// a new buffer is made available through the Flow API, or the
// end of the flow is reached.
private ByteBuffer current() throws IOException {
- while (current == null || !current.hasRemaining()) {
- // Check whether the stream is claused or exhausted
+ while (currentBuffer == null || !currentBuffer.hasRemaining()) {
+ // Check whether the stream is closed or exhausted
if (closed || failed != null) {
throw new IOException("closed", failed);
}
- if (current == LAST) break;
+ if (currentBuffer == LAST_BUFFER) break;
try {
- // Take a new buffer from the queue, blocking
+ if (currentList == null || currentList.isEmpty()) {
+ // Take a new list of buffers from the queue, blocking
// if none is available yet...
- if (DEBUG) System.err.println("Taking Buffer");
- current = buffers.take();
- if (DEBUG) System.err.println("Buffer Taken");
- // Check whether some exception was encountered
- // upstream
- if (closed || failed != null) {
+ if (DEBUG) err.println("Taking list of Buffers");
+ List<ByteBuffer> lb = buffers.take();
+ if (DEBUG) err.println("List of Buffers Taken");
+
+ // Check whether an exception was encountered upstream
+ if (closed || failed != null)
throw new IOException("closed", failed);
- }
// Check whether we're done.
- if (current == LAST) break;
+ if (lb == LAST_LIST) {
+ currentList = LAST_LIST;
+ currentBuffer = LAST_BUFFER;
+ break;
+ }
- // Inform the producer that it can start sending
- // us a new buffer
- Flow.Subscription s = subscription;
- if (s != null) s.request(1);
+ currentList = new ArrayList<>(lb); // TODO: lb is immutable
+ // Request another upstream item ( list of buffers )
+ Flow.Subscription s = subscription;
+ if (s != null)
+ s.request(1);
+ }
+ assert currentList != null;
+ assert !currentList.isEmpty();
+ if (DEBUG) err.println("Next Buffer");
+ currentBuffer = currentList.remove(0);
} catch (InterruptedException ex) {
// continue
}
}
- assert current == LAST || current.hasRemaining();
- return current;
+ assert currentBuffer == LAST_BUFFER || currentBuffer.hasRemaining();
+ return currentBuffer;
}
@Override
public int read(byte[] bytes, int off, int len) throws IOException {
// get the buffer to read from, possibly blocking if
// none is available
ByteBuffer buffer;
- if ((buffer = current()) == LAST) return -1;
+ if ((buffer = current()) == LAST_BUFFER) return -1;
// don't attempt to read more than what is available
// in the current buffer.
int read = Math.min(buffer.remaining(), len);
assert read > 0 && read <= buffer.remaining();
@@ -173,26 +188,26 @@
}
@Override
public int read() throws IOException {
ByteBuffer buffer;
- if ((buffer = current()) == LAST) return -1;
+ if ((buffer = current()) == LAST_BUFFER) return -1;
return buffer.get() & 0xFF;
}
@Override
public void onSubscribe(Flow.Subscription s) {
this.subscription = s;
s.request(Math.max(2, buffers.remainingCapacity() + 1));
}
@Override
- public synchronized void onNext(ByteBuffer t) {
+ public synchronized void onNext(List<ByteBuffer> t) {
try {
- if (DEBUG) System.err.println("next buffer received");
+ if (DEBUG) err.println("next item received");
buffers.put(t);
- if (DEBUG) System.err.println("buffered offered");
+ if (DEBUG) err.println("item offered");
} catch (Exception ex) {
failed = ex;
try {
close();
} catch (IOException ex1) {
@@ -207,11 +222,11 @@
}
@Override
public synchronized void onComplete() {
subscription = null;
- onNext(LAST);
+ onNext(LAST_LIST);
}
@Override
public void close() throws IOException {
synchronized (this) {
@@ -273,11 +288,11 @@
// System.out.println(
// client.sendAsync(request, HttpResponse.BodyHandler.asString()).get().body());
CompletableFuture<HttpResponse<InputStream>> handle =
client.sendAsync(request, new HttpInputStreamHandler());
- if (DEBUG) System.err.println("Request sent");
+ if (DEBUG) err.println("Request sent");
HttpResponse<InputStream> pending = handle.get();
// At this point, the response headers have been received, but the
// response body may not have arrived yet. This comes from
@@ -299,12 +314,12 @@
// charset.get() will throw NPE if the content is not textual.
Reader r = new InputStreamReader(is, charset.get())) {
char[] buff = new char[32];
int off=0, n=0;
- if (DEBUG) System.err.println("Start receiving response body");
- if (DEBUG) System.err.println("Charset: " + charset.get());
+ if (DEBUG) err.println("Start receiving response body");
+ if (DEBUG) err.println("Charset: " + charset.get());
// Start consuming the InputStream as the data arrives.
// Will block until there is something to read...
while ((n = r.read(buff, off, buff.length - off)) > 0) {
assert (buff.length - off) > 0;
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