Add an asByteArrayAsync method taking promise for Content.Source

jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/Content.java

@@ -326,7 +326,7 @@ static ByteBuffer asByteBuffer(Source source) throws IOException
          * @param maxSize The maximum size to read, or -1 for no limit
          * @return A {@link CompletableFuture} that will be completed when the complete content is read or
          * failed if the max size is exceeded or there is a read error.
-         * @deprecated no replacement
+         * @deprecated see {@link #asByteArrayAsync(Source, int, Promise)}
          */
         @Deprecated(forRemoval = true, since = "12.0.15")
         static CompletableFuture<byte[]> asByteArrayAsync(Source source, int maxSize)
@@ -340,6 +340,33 @@ static CompletableFuture<byte[]> asByteArrayAsync(Source source, int maxSize)
             });
         }
 
+        /**
+         * <p>Reads, non-blocking, the whole content source into a {@code byte} array.</p>
+         *
+         * @param source the source to read
+         * @param maxSize The maximum size to read, or -1 for no limit
+         * @param promise the promise to notify when the whole content has been read into a byte array.
+         */
+        static void asByteArrayAsync(Source source, int maxSize, Promise<byte[]> promise)
+        {
+            asRetainableByteBuffer(source, null, false, maxSize, new Promise.Completable<>()
+            {
+                @Override
+                public void succeeded(RetainableByteBuffer result)
+                {
+                    super.succeeded(result);
+                    promise.succeeded(result.takeByteArray());
+                }
+
+                @Override
+                public void failed(Throwable x)
+                {
+                    super.failed(x);
+                    promise.failed(x);
+                }
+            });
+        }
+
         /**
          * <p>Reads, non-blocking, the whole content source into a {@link ByteBuffer}.</p>
          *

jetty-core/jetty-io/src/test/java/org/eclipse/jetty/io/ContentSourceTest.java

@@ -1036,7 +1036,8 @@ public void testAsByteArrayAsync() throws Exception
     {
         TestContentSource source = new TestContentSource();
 
-        CompletableFuture<byte[]> completableFuture = Content.Source.asByteArrayAsync(source, -1);
+        FuturePromise<byte[]> promise = new FuturePromise<>();
+        Content.Source.asByteArrayAsync(source, -1, promise);
 
         Retainable.ReferenceCounter counter = new Retainable.ReferenceCounter();
         counter.retain();
@@ -1046,7 +1047,7 @@ public void testAsByteArrayAsync() throws Exception
         assertNotNull(todo);
         source.add(Content.Chunk.asChunk(BufferUtil.toBuffer("hello"), false, counter));
         todo.run();
-        assertFalse(completableFuture.isDone());
+        assertFalse(promise.isDone());
 
         todo = source.takeDemand();
         assertNotNull(todo);
@@ -1056,9 +1057,9 @@ public void testAsByteArrayAsync() throws Exception
 
         todo = source.takeDemand();
         assertNull(todo);
-        assertTrue(completableFuture.isDone());
+        assertTrue(promise.isDone());
 
-        byte[] buffer = completableFuture.get();
+        byte[] buffer = promise.get();
         assertNotNull(buffer);
 
         assertThat(new String(buffer, UTF_8), equalTo("hello cruel world"));