Back off if encoding is already given

riptide-compression/README.md

@@ -50,6 +50,27 @@ In order to specify the compression algorithm you can pass in a custom `Compress
 new RequestCompressionPlugin(Compression.of("br", BrotliOutputStream::new));
 ```
 
+## Usage
+
+```java
+http.post("/events")
+        .contentType(MediaType.APPLICATION_JSON)
+        .body(asList(events))
+        .call(pass())
+        .join();
+```
+
+All request bodies will be compressed using the configured compression method using `chunked` transfer-encoding.
+
+If there is already a `Content-Encoding` specified on the request, the plugin does nothing.
+
+### Limitations
+
+* You must only configure a single `RequestCompressionPlugin` as only a single encoding is applied currently.
+* Starting with Spring 4.3 the `Netty4ClientHttpRequestFactory` unconditionally adds a `Content-Length` header,
+which breaks if used together with  `RequestCompressionPlugin`. Use `riptide-httpclient` instead.
+
+
 ## Getting Help
 
 If you have questions, concerns, bug reports, etc., please file an issue in this repository's [Issue Tracker](../../../../issues).

riptide-compression/src/main/java/org/zalando/riptide/compression/RequestCompressionPlugin.java

@@ -36,7 +36,7 @@ public RequestExecution aroundNetwork(final RequestExecution execution) {
         return arguments -> {
             final Entity entity = arguments.getEntity();
 
-            if (entity.isEmpty()) {
+            if (entity.isEmpty() || arguments.getHeaders().containsKey(CONTENT_ENCODING)) {
                 return execution.execute(arguments);
             }
 

riptide-compression/src/test/java/org/zalando/riptide/compression/GzipClientDriver.java

@@ -13,12 +13,12 @@
 @Hack
 final class GzipClientDriver extends ClientDriver {
 
+    private int port;
+
     static ClientDriver create() {
         return new GzipClientDriver(new DefaultClientDriverJettyHandler(new DefaultRequestMatcher()));
     }
 
-    private int port;
-
     private GzipClientDriver(ClientDriverJettyHandler handler) {
         super(handler);
     }

riptide-compression/src/test/java/org/zalando/riptide/compression/RequestCompressionPluginTest.java

@@ -30,6 +30,7 @@
 import static java.util.concurrent.Executors.newSingleThreadExecutor;
 import static org.hamcrest.Matchers.emptyString;
 import static org.hamcrest.Matchers.equalTo;
+import static org.springframework.http.HttpHeaders.CONTENT_ENCODING;
 import static org.zalando.riptide.PassRoute.pass;
 
 class RequestCompressionPluginTest {
@@ -46,7 +47,7 @@ void tearDown() throws Exception {
 
     @ParameterizedTest
     @ArgumentsSource(RequestFactorySource.class)
-    void shouldCompressRequestUsingFactory(final ClientHttpRequestFactory factory) {
+    void shouldCompressRequestBody(final ClientHttpRequestFactory factory) {
         driver.addExpectation(onRequestTo("/")
                         .withMethod(POST)
                         .withHeader("X-Content-Encoding", "gzip") // written by Jetty's GzipHandler
@@ -63,16 +64,17 @@ void shouldCompressRequestUsingFactory(final ClientHttpRequestFactory factory) {
 
     @ParameterizedTest
     @ArgumentsSource(RequestFactorySource.class)
-    void shouldNotCompressEmptyBody(final ClientHttpRequestFactory factory) {
+    void shouldNotCompressEmptyRequestBody(final ClientHttpRequestFactory factory) {
         driver.addExpectation(onRequestTo("/")
-                        .withBody(emptyString(), "text/plain")
+                        .withMethod(POST)
+                        .withBody(emptyString(), "application/json")
                         .withoutHeader("Content-Encoding")
                         .withoutHeader("X-Content-Encoding"),
                 giveResponse("", "text/plain"));
 
         final Http http = buildHttp(factory, new RequestCompressionPlugin());
-        http.get("/")
-                .contentType(MediaType.TEXT_PLAIN)
+        http.post("/")
+                .contentType(MediaType.APPLICATION_JSON)
                 .call(pass())
                 .join();
     }
@@ -95,6 +97,25 @@ void shouldCompressWithGivenAlgorithm(final ClientHttpRequestFactory factory) {
                 .join();
     }
 
+    @ParameterizedTest
+    @ArgumentsSource(RequestFactorySource.class)
+    void shouldBackOffIfAlreadyEncoded(final ClientHttpRequestFactory factory) {
+        driver.addExpectation(onRequestTo("/")
+                        .withMethod(POST)
+                        .withHeader("Content-Encoding", "custom") // not handled by Jetty
+                        .withoutHeader("X-Content-Encoding")
+                        .withBody(equalTo("{}"), "application/json"),
+                giveResponse("", "text/plain"));
+
+        final Http http = buildHttp(factory, new RequestCompressionPlugin());
+        http.post("/")
+                .header(CONTENT_ENCODING, "custom")
+                .contentType(MediaType.APPLICATION_JSON)
+                .body(new HashMap<>())
+                .call(pass())
+                .join();
+    }
+
     private Http buildHttp(final ClientHttpRequestFactory factory, final Plugin... plugins) {
         return Http.builder()
                 .executor(executor)
@@ -109,7 +130,7 @@ static class RequestFactorySource implements ArgumentsProvider {
         public Stream<? extends Arguments> provideArguments(ExtensionContext extensionContext) {
             return Stream.of(
                     new SimpleClientHttpRequestFactory(),
-                    new Netty4ClientHttpRequestFactory(),
+                    // new Netty4ClientHttpRequestFactory(), # broken, see #823
                     new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory()),
                     new ApacheClientHttpRequestFactory(HttpClients.createDefault(), Mode.BUFFERING),
                     new ApacheClientHttpRequestFactory(HttpClients.createDefault(), Mode.STREAMING)