Stub of the DMaaP Client 2.0 implementation

This is untested. Treat it as a proof of concept.

Change-Id: Ieeef7c9481324984c9772b216d001254dec11ae9
Issue-ID: DCAEGEN2-1368
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

4 files changed, 99 insertions, 20 deletions

diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpHeaders.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpHeaders.java
new file mode 100644
index 00000000..4ef43a59
--- /dev/null
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpHeaders.java
@@ -0,0 +1,34 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since April 2019
+ */
+public final class HttpHeaders {
+
+    private HttpHeaders() {
+    }
+
+    public static final String CONTENT_TYPE = "Content-Type";
+    public static final String CONTENT_LENGTH = "Content-Length";
+}
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java
index 78660833..33060c9f 100644
--- a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/HttpRequest.java
@@ -20,17 +20,11 @@
 
 package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
 
-import io.netty.buffer.ByteBuf;
 import io.vavr.collection.HashMap;
 import io.vavr.collection.Map;
-import java.util.function.BiFunction;
 import org.immutables.value.Value;
 import org.jetbrains.annotations.Nullable;
 import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
-import org.reactivestreams.Publisher;
-import reactor.core.publisher.Mono;
-import reactor.netty.NettyOutbound;
-import reactor.netty.http.client.HttpClientRequest;
 
 /**
  * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
@@ -43,6 +37,8 @@ public interface HttpRequest {
 
     HttpMethod method();
 
+    @Nullable RequestBody body();
+
     @Value.Default
     default RequestDiagnosticContext diagnosticContext() {
         return RequestDiagnosticContext.create();
@@ -53,11 +49,6 @@ public interface HttpRequest {
         return HashMap.empty();
     }
 
-    @Value.Default
-    default Publisher<ByteBuf> body() {
-        return Mono.empty();
-    }
-
     @Value.Derived
     default Map<String, String> headers() {
         final RequestDiagnosticContext ctx = diagnosticContext();
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java
index 514ea0bf..ed218887 100644
--- a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RequestBody.java
@@ -23,9 +23,14 @@ package org.onap.dcaegen2.services.sdk.rest.services.adapters.http;
 import com.google.gson.JsonElement;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufAllocator;
+import io.netty.buffer.Unpooled;
+import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
+import org.immutables.value.Value;
+import org.jetbrains.annotations.Nullable;
 import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.netty.ByteBufFlux;
 
@@ -33,20 +38,39 @@ import reactor.netty.ByteBufFlux;
  * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
  * @since March 2019
  */
-public final class RequestBody {
+@Value.Immutable
+public interface RequestBody {
 
-    private RequestBody() {
+    Publisher<ByteBuf> contents();
+
+    @Nullable Integer length();
+
+    static RequestBody chunkedFromString(Publisher<String> contents) {
+        return chunkedFromString(contents, StandardCharsets.UTF_8);
     }
 
-    public static Publisher<ByteBuf> fromString(String contents) {
+    static RequestBody chunkedFromString(Publisher<String> contents, Charset charset) {
+        return ImmutableRequestBody.builder()
+                .length(null)
+                .contents(ByteBufFlux.fromString(contents, charset, ByteBufAllocator.DEFAULT))
+                .build();
+    }
+
+    static RequestBody fromString(String contents) {
         return fromString(contents, StandardCharsets.UTF_8);
     }
 
-    public static Publisher<ByteBuf> fromString(String contents, Charset charset) {
-        return ByteBufFlux.fromString(Mono.just(contents), charset, ByteBufAllocator.DEFAULT);
+    static RequestBody fromString(String contents, Charset charset) {
+        ByteBuf encodedContents = ByteBufAllocator.DEFAULT.buffer();
+        encodedContents.writeCharSequence(contents, charset);
+
+        return ImmutableRequestBody.builder()
+                .length(encodedContents.readableBytes())
+                .contents(Mono.just(encodedContents.retain()))
+                .build();
     }
 
-    public static Publisher<ByteBuf> fromJson(JsonElement contents) {
+    static RequestBody fromJson(JsonElement contents) {
         return fromString(contents.toString());
     }
 
diff --git a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java
index f384c1c1..709f5e59 100644
--- a/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java
+++ b/rest-services/common-dependency/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/adapters/http/RxHttpClient.java
@@ -61,14 +61,44 @@ public class RxHttpClient {
     }
 
     ResponseReceiver<?> prepareRequest(HttpRequest request) {
-        return httpClient
+        final HttpClient theClient = httpClient
                 .doOnRequest((req, conn) -> logRequest(request.diagnosticContext(), req))
                 .doOnResponse((rsp, conn) -> logResponse(request.diagnosticContext(), rsp))
-                .headers(hdrs -> request.headers().forEach(hdr -> hdrs.set(hdr._1, hdr._2)))
+                .headers(hdrs -> request.headers().forEach(hdr -> hdrs.set(hdr._1, hdr._2)));
+
+        return prepareBody(request, theClient);
+    }
+
+    private ResponseReceiver<?> prepareBody(HttpRequest request, HttpClient theClient) {
+        if (request.body() == null) {
+            return prepareBodyWithoutContents(request, theClient);
+        } else {
+            return request.body().length() == null
+                    ? prepareBodyChunked(request, theClient)
+                    : prepareBodyUnchunked(request, theClient);
+        }
+    }
+
+    private ResponseReceiver<?> prepareBodyChunked(HttpRequest request, HttpClient theClient) {
+        return theClient
+                .chunkedTransfer(true)
+                .request(request.method().asNetty())
+                .send(request.body().contents())
+                .uri(request.url());
+    }
+
+    private ResponseReceiver<?> prepareBodyUnchunked(HttpRequest request, HttpClient theClient) {
+        return theClient
+                .headers(hdrs -> hdrs.set(HttpHeaders.CONTENT_LENGTH, request.body().length().toString()))
                 .request(request.method().asNetty())
-                .send(request.body())
+                .send(request.body().contents())
                 .uri(request.url());
+    }
 
+    private ResponseReceiver<?> prepareBodyWithoutContents(HttpRequest request, HttpClient theClient) {
+        return theClient
+                .request(request.method().asNetty())
+                .uri(request.url());
     }
 
     private void logRequest(RequestDiagnosticContext context, HttpClientRequest httpClientRequest) {