Refactor RestClientTransport to allow using other http client libraries (#584)

Author: swallez

Diff for: .github/workflows/checkstyle.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java-version: [ 11 ]
+        java-version: [ 17 ]
     steps:
       - uses: actions/checkout@v2
 

Diff for: example-transports/README.md

@@ -0,0 +1 @@
+This directory contains experimental implementations of the `TransportHttpClient` interface. They are to be used as examples and inspiration and should not be considered production-ready.

Diff for: example-transports/build.gradle.kts

@@ -0,0 +1,55 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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.
+ */
+
+plugins {
+    java
+    `java-library`
+    `java-test-fixtures`
+}
+
+tasks.withType<Test> {
+    useJUnitPlatform()
+}
+
+java {
+    targetCompatibility = JavaVersion.VERSION_17
+}
+
+
+dependencies {
+    val jacksonVersion = "2.13.3"
+
+    api("io.netty", "netty-codec-http", "4.1.93.Final")
+
+    implementation(project(":java-client"))
+
+    // Apache 2.0
+    // https://github.com/FasterXML/jackson
+    testImplementation("com.fasterxml.jackson.core", "jackson-core", jacksonVersion)
+    testImplementation("com.fasterxml.jackson.core", "jackson-databind", jacksonVersion)
+
+    // EPL-2.0
+    // https://junit.org/junit5/
+    testImplementation("org.junit.jupiter:junit-jupiter-api:5.9.0")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.9.0")
+
+}
+repositories {
+    mavenCentral()
+}

Diff for: example-transports/src/main/java/co/elastic/clients/transport/netty/InputStreamBinaryData.java

@@ -0,0 +1,90 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 co.elastic.clients.transport.netty;
+
+import co.elastic.clients.util.BinaryData;
+import co.elastic.clients.util.NoCopyByteArrayOutputStream;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+
+public class InputStreamBinaryData implements BinaryData {
+
+    private final String contentType;
+    private final InputStream inputStream;
+    private boolean consumed = false;
+
+    public InputStreamBinaryData(String contentType, InputStream inputStream) {
+        this.contentType = contentType;
+        this.inputStream = inputStream;
+    }
+
+    @Override
+    public String contentType() {
+        return contentType;
+    }
+
+    @Override
+    public void writeTo(OutputStream out) throws IOException {
+        consume();
+        try {
+            byte[] buffer = new byte[8192];
+            int len;
+            while ((len = inputStream.read(buffer)) > 0) {
+                out.write(buffer, 0, len);
+            }
+        } finally {
+            inputStream.close();
+        }
+    }
+
+    @Override
+    public ByteBuffer asByteBuffer() throws IOException {
+        consume();
+        NoCopyByteArrayOutputStream baos = new NoCopyByteArrayOutputStream();
+        writeTo(baos);
+        return baos.asByteBuffer();
+    }
+
+    @Override
+    public InputStream asInputStream() throws IOException {
+        consume();
+        return inputStream;
+    }
+
+    @Override
+    public boolean isRepeatable() {
+        return false;
+    }
+
+    @Override
+    public long size() {
+        return -1;
+    }
+
+    private void consume() throws IllegalStateException {
+        if (consumed) {
+            throw new IllegalStateException("Data has already been consumed");
+        }
+        consumed = true;
+    }
+}

Diff for: example-transports/src/main/java/co/elastic/clients/transport/netty/NettyElasticsearchTransport.java

@@ -0,0 +1,70 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 co.elastic.clients.transport.netty;
+
+import co.elastic.clients.json.JsonpMapper;
+import co.elastic.clients.transport.ElasticsearchTransportBase;
+import co.elastic.clients.transport.TransportOptions;
+import co.elastic.clients.transport.http.TransportHttpClient;
+
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+
+public class NettyElasticsearchTransport extends ElasticsearchTransportBase {
+
+    public NettyElasticsearchTransport(TransportHttpClient.Node node, TransportOptions options, JsonpMapper jsonpMapper) {
+        super(new SingleNodeHttpClient(new NettyTransportHttpClient(), node), options, jsonpMapper);
+    }
+
+    public static class SingleNodeHttpClient implements TransportHttpClient {
+        private final TransportHttpClient client;
+        private final Node node;
+
+        public SingleNodeHttpClient(TransportHttpClient client, Node node) {
+            this.client = client;
+            this.node = node;
+        }
+
+        @Override
+        public TransportOptions createOptions(@Nullable TransportOptions options) {
+            return client.createOptions(options);
+        }
+
+        @Override
+        public Response performRequest(
+            String endpointId, @Nullable Node ignoredNode, Request request, TransportOptions options
+        ) throws IOException {
+            return client.performRequest(endpointId, node, request, options);
+        }
+
+        @Override
+        public CompletableFuture<Response> performRequestAsync(
+            String endpointId, @Nullable Node ignoredNode, Request request, TransportOptions options
+        ) {
+            return client.performRequestAsync(endpointId, node, request, options);
+        }
+
+        @Override
+        public void close() throws IOException {
+            client.close();
+        }
+    }
+}