4.x: HTTP/2.0 Client trailers support #6544

http/http/src/main/java/io/helidon/http/ClientResponseTrailers.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.http;
+
+/**
+ * HTTP Trailer headers of a client response.
+ */
+public interface ClientResponseTrailers extends io.helidon.http.Headers {
+
+    /**
+     * Create new trailers from headers future.
+     *
+     * @param headers trailer headers
+     * @return new client trailers from headers future
+     */
+    static ClientResponseTrailers create(io.helidon.http.Headers headers) {
+        return new ClientResponseTrailersImpl(headers);
+    }
+
+    /**
+     * Create new empty trailers.
+     *
+     * @return new empty client trailers
+     */
+    static ClientResponseTrailers create() {
+        return new ClientResponseTrailersImpl();
+    }
+}

http/http/src/main/java/io/helidon/http/ClientResponseTrailersImpl.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.http;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.function.Supplier;
+
+class ClientResponseTrailersImpl implements ClientResponseTrailers {
+    private static final Headers EMPTY_TRAILERS = WritableHeaders.create();
+    private final Headers trailers;
+
+    ClientResponseTrailersImpl(Headers trailers) {
+        this.trailers = trailers;
+    }
+
+    ClientResponseTrailersImpl() {
+        this.trailers = EMPTY_TRAILERS;
+    }
+
+    @Override
+    public List<String> all(HeaderName name, Supplier<List<String>> defaultSupplier) {
+        return trailers.all(name, defaultSupplier);
+    }
+
+    @Override
+    public boolean contains(HeaderName name) {
+        return trailers.contains(name);
+    }
+
+    @Override
+    public boolean contains(Header value) {
+        return trailers.contains(value);
+    }
+
+    @Override
+    public Header get(HeaderName name) {
+        return trailers.get(name);
+    }
+
+    @Override
+    public int size() {
+        return trailers.size();
+    }
+
+    @Override
+    public List<HttpMediaType> acceptedTypes() {
+        return trailers.acceptedTypes();
+    }
+
+    @Override
+    public Iterator<Header> iterator() {
+        return trailers.iterator();
+    }
+}

http/http2/src/main/java/io/helidon/http/http2/Http2Stream.java

@@ -40,11 +40,19 @@ public interface Http2Stream {
     /**
      * Headers received.
      *
-     * @param headers     request headers
+     * @param headers     headers
      * @param endOfStream whether these headers are the last data that would be received
      */
     void headers(Http2Headers headers, boolean endOfStream);
 
+    /**
+     * Trailers received.
+     *
+     * @param headers     trailer headers
+     * @param endOfStream whether these headers are the last data that would be received
+     */
+    void trailers(Http2Headers headers, boolean endOfStream);
+
     /**
      * Data frame.
      *

webclient/api/src/main/java/io/helidon/webclient/api/ClientResponseBase.java

@@ -17,6 +17,7 @@
 package io.helidon.webclient.api;
 
 import io.helidon.http.ClientResponseHeaders;
+import io.helidon.http.ClientResponseTrailers;
 import io.helidon.http.Status;
 
 /**
@@ -37,6 +38,15 @@ interface ClientResponseBase {
      */
     ClientResponseHeaders headers();
 
+    /**
+     * Response trailer headers.
+     * Blocks until trailers are available.
+     *
+     * @throws java.lang.IllegalStateException when invoked before entity is requested
+     * @return trailers
+     */
+    ClientResponseTrailers trailers();
+
     /**
      * URI of the last request. (after redirection)
      *

webclient/api/src/main/java/io/helidon/webclient/api/ClientResponseTypedImpl.java

@@ -17,6 +17,7 @@
 package io.helidon.webclient.api;
 
 import io.helidon.http.ClientResponseHeaders;
+import io.helidon.http.ClientResponseTrailers;
 import io.helidon.http.Status;
 
 class ClientResponseTypedImpl<T> implements ClientResponseTyped<T> {
@@ -51,6 +52,11 @@ public ClientResponseHeaders headers() {
         return response.headers();
     }
 
+    @Override
+    public ClientResponseTrailers trailers() {
+        return response.trailers();
+    }
+
     @Override
     public ClientUri lastEndpointUri() {
         return response.lastEndpointUri();

webclient/api/src/main/java/io/helidon/webclient/api/WebClientServiceResponseBlueprint.java

@@ -22,12 +22,13 @@
 
 import io.helidon.builder.api.Prototype;
 import io.helidon.http.ClientResponseHeaders;
+import io.helidon.http.ClientResponseTrailers;
 import io.helidon.http.Status;
 
 /**
  * Response which is created upon receiving of server response.
  */
-@Prototype.Blueprint
+@Prototype.Blueprint(decorator = WebClientServiceResponseDecorator.class)
 interface WebClientServiceResponseBlueprint {
 
     /**
@@ -37,6 +38,13 @@ interface WebClientServiceResponseBlueprint {
      */
     ClientResponseHeaders headers();
 
+    /**
+     * Received response trailer headers.
+     *
+     * @return immutable response trailer headers
+     */
+    CompletableFuture<ClientResponseTrailers> trailers();
+
     /**
      * Status of the response.
      *

webclient/api/src/main/java/io/helidon/webclient/api/WebClientServiceResponseDecorator.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.helidon.webclient.api;
+
+import java.util.concurrent.CompletableFuture;
+
+import io.helidon.builder.api.Prototype;
+import io.helidon.http.ClientResponseTrailers;
+
+class WebClientServiceResponseDecorator implements Prototype.BuilderDecorator<WebClientServiceResponse.BuilderBase<?, ?>> {
+    @Override
+    public void decorate(WebClientServiceResponse.BuilderBase<?, ?> target) {
+        if (target.trailers().isEmpty()) {
+            // Empty trailers by default
+            target.trailers(CompletableFuture.completedFuture(ClientResponseTrailers.create()));
+        }
+    }
+}

webclient/http1/src/main/java/io/helidon/webclient/http1/Http1CallChainBase.java

@@ -511,8 +511,10 @@ private void ensureBuffer() {
                                                            + BufferData.create(hex.getBytes(US_ASCII)).debugDataHex());
             }
             if (length == 0) {
-                reader.skip(2); // second CRLF finishing the entity
-
+                if (reader.startsWithNewLine()) {
+                    // No trailers, skip second CRLF
+                    reader.skip(2);
+                }
                 helidonSocket.log(LOGGER, TRACE, "read last (empty) chunk");
                 finished = true;
                 currentBuffer = null;

webclient/http1/src/main/java/io/helidon/webclient/http1/Http1ClientResponseImpl.java

@@ -17,9 +17,13 @@
 package io.helidon.webclient.http1;
 
 import java.io.InputStream;
+import java.time.Duration;
 import java.util.List;
 import java.util.ServiceLoader;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import io.helidon.common.GenericType;
@@ -28,11 +32,11 @@
 import io.helidon.common.media.type.ParserMode;
 import io.helidon.http.ClientRequestHeaders;
 import io.helidon.http.ClientResponseHeaders;
+import io.helidon.http.ClientResponseTrailers;
 import io.helidon.http.HeaderNames;
 import io.helidon.http.HeaderValues;
 import io.helidon.http.Http1HeadersParser;
 import io.helidon.http.Status;
-import io.helidon.http.WritableHeaders;
 import io.helidon.http.media.MediaContext;
 import io.helidon.http.media.ReadableEntity;
 import io.helidon.http.media.ReadableEntityBase;
@@ -49,9 +53,10 @@ class Http1ClientResponseImpl implements Http1ClientResponse {
     @SuppressWarnings("rawtypes")
     private static final List<SourceHandlerProvider> SOURCE_HANDLERS
             = HelidonServiceLoader.builder(ServiceLoader.load(SourceHandlerProvider.class)).build().asList();
-
+    private static final long ENTITY_LENGTH_CHUNKED = -1;
     private final AtomicBoolean closed = new AtomicBoolean();
 
+    private final HttpClientConfig clientConfig;
     private final Status responseStatus;
     private final ClientRequestHeaders requestHeaders;
     private final ClientResponseHeaders responseHeaders;
@@ -65,9 +70,9 @@ class Http1ClientResponseImpl implements Http1ClientResponse {
     private final ClientUri lastEndpointUri;
 
     private final ClientConnection connection;
+    private final CompletableFuture<io.helidon.http.Headers> trailers = new CompletableFuture<>();
+    private boolean entityRequested;
     private long entityLength;
-    private boolean entityFullyRead;
-    private WritableHeaders<?> trailers;
 
     Http1ClientResponseImpl(HttpClientConfig clientConfig,
                             Status responseStatus,
@@ -79,6 +84,7 @@ class Http1ClientResponseImpl implements Http1ClientResponse {
                             ParserMode parserMode,
                             ClientUri lastEndpointUri,
                             CompletableFuture<Void> whenComplete) {
+        this.clientConfig = clientConfig;
         this.responseStatus = responseStatus;
         this.requestHeaders = requestHeaders;
         this.responseHeaders = responseHeaders;
@@ -92,7 +98,7 @@ class Http1ClientResponseImpl implements Http1ClientResponse {
         if (responseHeaders.contains(HeaderNames.CONTENT_LENGTH)) {
             this.entityLength = Long.parseLong(responseHeaders.get(HeaderNames.CONTENT_LENGTH).value());
         } else if (responseHeaders.contains(HeaderValues.TRANSFER_ENCODING_CHUNKED)) {
-            this.entityLength = -1;
+            this.entityLength = ENTITY_LENGTH_CHUNKED;
         }
         if (responseHeaders.contains(HeaderNames.TRAILER)) {
             this.hasTrailers = true;
@@ -113,8 +119,38 @@ public ClientResponseHeaders headers() {
         return responseHeaders;
     }
 
+    @Override
+    public ClientResponseTrailers trailers() {
+        if (hasTrailers) {
+            // Block until trailers arrive
+            Duration timeout = clientConfig.readTimeout()
+                    .orElseGet(() -> clientConfig.socketOptions().readTimeout());
+
+            if (!this.entityRequested) {
+                throw new IllegalStateException("Trailers requested before reading entity.");
+            }
+
+            try {
+                return ClientResponseTrailers.create(this.trailers.get(timeout.toMillis(), TimeUnit.MILLISECONDS));
+            } catch (TimeoutException e) {
+                throw new IllegalStateException("Timeout " + timeout + " reached while waiting for trailers.", e);
+            } catch (InterruptedException e) {
+                throw new IllegalStateException("Interrupted while waiting for trailers.", e);
+            } catch (ExecutionException e) {
+                if (e.getCause() instanceof IllegalStateException ise) {
+                    throw ise;
+                } else {
+                    throw new IllegalStateException(e.getCause());
+                }
+            }
+        } else {
+            return ClientResponseTrailers.create();
+        }
+    }
+
     @Override
     public ReadableEntity entity() {
+        this.entityRequested = true;
         return entity(requestHeaders, responseHeaders);
     }
 
@@ -125,11 +161,15 @@ public void close() {
                 if (headers().contains(HeaderValues.CONNECTION_CLOSE)) {
                     connection.closeResource();
                 } else {
-                    if (entityFullyRead || entityLength == 0) {
+                    if (entityLength == 0) {
+                        connection.releaseResource();
+                    } else if (entityLength == ENTITY_LENGTH_CHUNKED) {
                         if (hasTrailers) {
                             readTrailers();
+                            connection.releaseResource();
+                        } else {
+                            connection.closeResource();
                         }
-                        connection.releaseResource();
                     } else {
                         connection.closeResource();
                     }
@@ -176,7 +216,7 @@ private ReadableEntity entity(ClientRequestHeaders requestHeaders,
     }
 
     private void readTrailers() {
-        this.trailers = Http1HeadersParser.readHeaders(connection.reader(), 1024, true);
+        this.trailers.complete(Http1HeadersParser.readHeaders(connection.reader(), 1024, true));
     }
 
     private BufferData readBytes(int estimate) {