Azcore cleanup httppipeline apis

applicationconfig/client/src/main/java/com/azure/applicationconfig/ConfigurationAsyncClientBuilder.java

@@ -128,9 +128,10 @@ public ConfigurationAsyncClient build() {
 
         policies.add(new HttpLoggingPolicy(httpLogDetailLevel));
 
-        HttpPipeline pipeline = httpClient == null
-            ? new HttpPipeline(policies)
-            : new HttpPipeline(httpClient, policies);
+        HttpPipeline pipeline = HttpPipeline.builder()
+            .policies(policies.toArray(new HttpPipelinePolicy[0]))
+            .httpClient(httpClient)
+            .build();
 
         return new ConfigurationAsyncClient(serviceEndpoint, pipeline);
     }

core/azure-core-management/src/main/java/com/azure/core/management/AzureProxy.java

@@ -192,14 +192,17 @@ public static HttpPipeline createDefaultPipeline(Class<?> swaggerInterface, Asyn
     public static HttpPipeline createDefaultPipeline(Class<?> swaggerInterface, HttpPipelinePolicy credentialsPolicy) {
         // Order in which policies applied will be the order in which they appear in the array
         //
-        List<HttpPipelinePolicy> policies = new ArrayList<HttpPipelinePolicy>();
+        List<HttpPipelinePolicy> policies = new ArrayList<>();
         policies.add(new UserAgentPolicy(getDefaultUserAgentString(swaggerInterface)));
         policies.add(new RetryPolicy());
         policies.add(new CookiePolicy());
         if (credentialsPolicy != null) {
             policies.add(credentialsPolicy);
         }
-        return new HttpPipeline(policies.toArray(new HttpPipelinePolicy[policies.size()]));
+
+        return HttpPipeline.builder()
+            .policies(policies.toArray(new HttpPipelinePolicy[0]))
+            .build();
     }
 
     /**

core/azure-core-management/src/test/java/com/azure/core/management/AzureProxyTests.java

@@ -850,7 +850,9 @@ public Mono<HttpResponse> send(HttpRequest request) {
     }
 
     private static <T> T createMockService(Class<T> serviceClass, MockAzureHttpClient httpClient) {
-        HttpPipeline pipeline = new HttpPipeline(httpClient);
+        HttpPipeline pipeline = HttpPipeline.builder()
+            .httpClient(httpClient)
+            .build();
 
         return AzureProxy.create(serviceClass, null, pipeline, SERIALIZER);
     }

core/azure-core-management/src/test/java/com/azure/core/management/AzureProxyToRestProxyTests.java

@@ -745,7 +745,9 @@ public void service18GetStatus500WithExpectedResponse500() {
     }
 
     private <T> T createService(Class<T> serviceClass) {
-        HttpPipeline pipeline = new HttpPipeline(createHttpClient());
+        HttpPipeline pipeline = HttpPipeline.builder()
+            .httpClient(createHttpClient())
+            .build();
         //
         return AzureProxy.create(serviceClass, null, pipeline, SERIALIZER);
     }

core/azure-core/src/main/java/com/azure/core/http/HttpPipeline.java

@@ -3,11 +3,10 @@
 
 package com.azure.core.http;
 
-import com.azure.core.util.Context;
 import com.azure.core.http.policy.HttpPipelinePolicy;
+import com.azure.core.util.Context;
 import reactor.core.publisher.Mono;
 
-import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
 
@@ -18,75 +17,47 @@ public final class HttpPipeline {
     private final HttpClient httpClient;
     private final HttpPipelinePolicy[] pipelinePolicies;
 
-    /**
-     * Creates a HttpPipeline holding array of policies that gets applied to all request initiated through
-     * {@link HttpPipeline#send(HttpPipelineCallContext)} and it's response.
-     *
-     * @param httpClient the http client to write request to wire and receive response from wire.
-     * @param pipelinePolicies pipeline policies in the order they need to applied, a copy of this array will
-     *                                  be made hence changing the original array after the creation of pipeline
-     *                                  will not  mutate the pipeline
-     */
-    public HttpPipeline(HttpClient httpClient, HttpPipelinePolicy... pipelinePolicies) {
-        Objects.requireNonNull(httpClient);
-        Objects.requireNonNull(pipelinePolicies);
-        this.pipelinePolicies = Arrays.copyOf(pipelinePolicies, pipelinePolicies.length);
-        this.httpClient = httpClient;
-    }
 
     /**
-     * Creates a HttpPipeline holding array of policies that gets applied all request initiated through
-     * {@link HttpPipeline#send(HttpPipelineCallContext)} and it's response.
+     * Creates a builder that can configure options for the HttpPipeline before creating an instance of it.
      *
-     * The default HttpClient {@link HttpClient#createDefault()} will be used to write request to wire and
-     * receive response from wire.
-     *
-     * @param pipelinePolicies pipeline policies in the order they need to applied, a copy of this array will
-     *                                  be made hence changing the original array after the creation of pipeline
-     *                                  will not  mutate the pipeline
+     * @return A new {@link HttpPipelineBuilder} to create a HttpPipeline from.
      */
-    public HttpPipeline(HttpPipelinePolicy... pipelinePolicies) {
-        this(HttpClient.createDefault(), pipelinePolicies);
+    public static HttpPipelineBuilder builder() {
+        return new HttpPipelineBuilder();
     }
 
     /**
      * Creates a HttpPipeline holding array of policies that gets applied to all request initiated through
      * {@link HttpPipeline#send(HttpPipelineCallContext)} and it's response.
      *
      * @param httpClient the http client to write request to wire and receive response from wire.
-     * @param pipelinePolicies pipeline policies in the order they need to applied, a copy of this list
-     *                         will be made so changing the original list after the creation of pipeline
-     *                         will not mutate the pipeline
+     * @param pipelinePolicies pipeline policies in the order they need to applied, a copy of this array will
+     *                                  be made hence changing the original array after the creation of pipeline
+     *                                  will not  mutate the pipeline
      */
-    public HttpPipeline(HttpClient httpClient, List<HttpPipelinePolicy> pipelinePolicies) {
+    HttpPipeline(HttpClient httpClient, List<HttpPipelinePolicy> pipelinePolicies) {
         Objects.requireNonNull(httpClient);
         Objects.requireNonNull(pipelinePolicies);
-        this.pipelinePolicies = pipelinePolicies.toArray(new HttpPipelinePolicy[0]);
         this.httpClient = httpClient;
+        this.pipelinePolicies = pipelinePolicies.toArray(new HttpPipelinePolicy[0]);
     }
 
     /**
-     * Creates a HttpPipeline holding array of policies that gets applied all request initiated through
-     * {@link HttpPipeline#send(HttpPipelineCallContext)} and it's response.
-     *
-     * The default HttpClient {@link HttpClient#createDefault()} will be used to write request to wire and
-     * receive response from wire.
-     *
-     * @param pipelinePolicies pipeline policies in the order they need to applied, a copy of this list
-     *                         will be made so changing the original list after the creation of pipeline
-     *                         will not mutate the pipeline
+     * Get the policy at the passed index in the pipeline.
+     * @param index index of the the policy to retrieve.
+     * @return the policy stored at that index.
      */
-    public HttpPipeline(List<HttpPipelinePolicy> pipelinePolicies) {
-        this(HttpClient.createDefault(), pipelinePolicies);
+    public HttpPipelinePolicy getPolicy(final int index) {
+        return this.pipelinePolicies[index];
     }
 
     /**
-     * Get the policies in the pipeline.
-     *
-     * @return policies in the pipeline
+     * Get the count of policies in the pipeline.
+     * @return count of policies.
      */
-    public HttpPipelinePolicy[] pipelinePolicies() {
-        return Arrays.copyOf(this.pipelinePolicies, this.pipelinePolicies.length);
+    public int getPolicyCount() {
+        return this.pipelinePolicies.length;
     }
 
     /**
@@ -99,34 +70,23 @@ public HttpClient httpClient() {
     }
 
     /**
-     * Creates a new context local to the provided http request.
-     *
-     * @param httpRequest the request for a context needs to be created
-     * @return the request context
-     */
-    public HttpPipelineCallContext newContext(HttpRequest httpRequest) {
-        return new HttpPipelineCallContext(httpRequest);
-    }
-
-    /**
-     * Creates a new context local to the provided http request.
+     * Wraps the request in a context and send it through pipeline.
      *
-     * @param httpRequest the request for a context needs to be created
-     * @param data the data to associate with the context
-     * @return the request context
+     * @param request the request
+     * @return a publisher upon subscription flows the context through policies, sends the request and emits response upon completion
      */
-    public HttpPipelineCallContext newContext(HttpRequest httpRequest, Context data) {
-        return new HttpPipelineCallContext(httpRequest, data);
+    public Mono<HttpResponse> send(HttpRequest request) {
+        return this.send(new HttpPipelineCallContext(request));
     }
 
     /**
-     * Wraps the request in a context and send it through pipeline.
-     *
+     * Wraps the request in a context with additional metadata and sends it through the pipeline.
      * @param request the request
+     * @param data additional metadata to pass along in the request
      * @return a publisher upon subscription flows the context through policies, sends the request and emits response upon completion
      */
-    public Mono<HttpResponse> send(HttpRequest request) {
-        return this.send(this.newContext(request));
+    public Mono<HttpResponse> send(HttpRequest request, Context data) {
+        return this.send(new HttpPipelineCallContext(request, data));
     }
 
     /**

core/azure-core/src/main/java/com/azure/core/http/HttpPipelineBuilder.java

@@ -0,0 +1,88 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.core.http;
+
+import com.azure.core.http.policy.HttpPipelinePolicy;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * This class provides a fluent builder API to help aid the configuration and instantiation of the {@link HttpPipeline},
+ * calling {@link HttpPipelineBuilder#build() build} constructs an instance of the pipeline.
+ *
+ * <p>A pipeline is configured with a HttpClient that sends the request, if no client is set a default is used.
+ * A pipeline may be configured with a list of policies that are applied to each request.</p>
+ *
+ * <p><strong>Code Samples</strong></p>
+ *
+ * <p>Create a pipeline without configuration</p>
+ *
+ * <pre>
+ * HttpPipeline.builder()
+ *     .build();
+ * </pre>
+ *
+ * <p>Create a pipeline using the default HTTP client and a retry policy</p>
+ *
+ * <pre>
+ * HttpPipeline.builder()
+ *     .httpClient(HttpClient.createDefault())
+ *     .policies(new RetryPolicy())
+ *     .build();
+ * </pre>
+ *
+ * @see HttpPipeline
+ */
+public class HttpPipelineBuilder {
+    private HttpClient httpClient;
+    private List<HttpPipelinePolicy> pipelinePolicies;
+
+
+    HttpPipelineBuilder() {
+    }
+
+    /**
+     * Creates a {@link HttpPipeline} based on options set in the Builder. Every time {@code build()} is
+     * called, a new instance of {@link HttpPipeline} is created.
+     *
+     * If HttpClient is not set then the {@link HttpClient#createDefault() default HttpClient} is used.
+     *
+     * @return A HttpPipeline with the options set from the builder.
+     */
+    public HttpPipeline build() {
+        List<HttpPipelinePolicy> policies = (pipelinePolicies == null) ? new ArrayList<>() : pipelinePolicies;
+        HttpClient client = (httpClient == null) ? HttpClient.createDefault() : httpClient;
+
+        return new HttpPipeline(client, policies);
+    }
+
+    /**
+     * Sets the HttpClient that the pipeline will use to send requests.
+     *
+     * @param httpClient The HttpClient the pipeline will use when sending requests.
+     * @return The updated HttpPipelineBuilder object.
+     */
+    public HttpPipelineBuilder httpClient(HttpClient httpClient) {
+        this.httpClient = httpClient;
+        return this;
+    }
+
+    /**
+     * Adds {@link HttpPipelinePolicy policies} to the set of policies that the pipeline will use
+     * when sending requests.
+     *
+     * @param policies Policies to add to the policy set.
+     * @return The updated HttpPipelineBuilder object.
+     */
+    public HttpPipelineBuilder policies(HttpPipelinePolicy... policies) {
+        if (pipelinePolicies == null) {
+            pipelinePolicies = new ArrayList<>();
+        }
+
+        this.pipelinePolicies.addAll(Arrays.asList(policies));
+        return this;
+    }
+}

core/azure-core/src/main/java/com/azure/core/http/HttpPipelineNextPolicy.java

@@ -34,16 +34,16 @@ public class HttpPipelineNextPolicy {
      * @return a publisher upon subscription invokes next policy and emits response from the policy.
      */
     public Mono<HttpResponse> process() {
-        final int size = this.pipeline.pipelinePolicies().length;
+        final int size = this.pipeline.getPolicyCount();
         if (this.currentPolicyIndex > size) {
             return Mono.error(new IllegalStateException("There is no more policies to execute."));
+        }
+
+        this.currentPolicyIndex++;
+        if (this.currentPolicyIndex == size) {
+            return this.pipeline.httpClient().send(this.context.httpRequest());
         } else {
-            this.currentPolicyIndex++;
-            if (this.currentPolicyIndex == size) {
-                return this.pipeline.httpClient().send(this.context.httpRequest());
-            } else {
-                return this.pipeline.pipelinePolicies()[this.currentPolicyIndex].process(this.context, this);
-            }
+            return this.pipeline.getPolicy(this.currentPolicyIndex).process(this.context, this);
         }
     }
 

core/azure-core/src/main/java/com/azure/core/implementation/RestProxy.java

@@ -7,7 +7,6 @@
 import com.azure.core.annotations.ResumeOperation;
 import com.azure.core.credentials.ServiceClientCredentials;
 import com.azure.core.exception.HttpRequestException;
-import com.azure.core.util.Context;
 import com.azure.core.http.HttpHeader;
 import com.azure.core.http.HttpHeaders;
 import com.azure.core.http.HttpMethod;
@@ -34,6 +33,7 @@
 import com.azure.core.implementation.util.FluxUtil;
 import com.azure.core.implementation.util.ImplUtils;
 import com.azure.core.implementation.util.TypeUtil;
+import com.azure.core.util.Context;
 import io.netty.buffer.ByteBuf;
 import reactor.core.Exceptions;
 import reactor.core.publisher.Flux;
@@ -112,7 +112,7 @@ public SerializerAdapter serializer() {
      * @return a {@link Mono} that emits HttpResponse asynchronously
      */
     public Mono<HttpResponse> send(HttpRequest request, Context contextData) {
-        return httpPipeline.send(httpPipeline.newContext(request, contextData));
+        return httpPipeline.send(request, contextData);
     }
 
     @Override
@@ -558,7 +558,10 @@ public static HttpPipeline createDefaultPipeline(HttpPipelinePolicy credentialsP
         if (credentialsPolicy != null) {
             policies.add(credentialsPolicy);
         }
-        return new HttpPipeline(policies.toArray(new HttpPipelinePolicy[policies.size()]));
+
+        return HttpPipeline.builder()
+            .policies(policies.toArray(new HttpPipelinePolicy[0]))
+            .build();
     }
 
     /**

core/azure-core/src/test/java/com/azure/core/CredentialsTests.java

@@ -28,9 +28,10 @@ public void basicCredentialsTest() throws Exception {
             return next.process();
         };
         //
-        final HttpPipeline pipeline = new HttpPipeline(new MockHttpClient(),
-                new CredentialsPolicy(credentials),
-                auditorPolicy);
+        final HttpPipeline pipeline = HttpPipeline.builder()
+            .httpClient(new MockHttpClient())
+            .policies(new CredentialsPolicy(credentials), auditorPolicy)
+            .build();
 
 
         HttpRequest request = new HttpRequest(HttpMethod.GET, new URL("http://localhost"));
@@ -47,9 +48,10 @@ public void tokenCredentialsTest() throws Exception {
             return next.process();
         };
 
-        final HttpPipeline pipeline = new HttpPipeline(new MockHttpClient(),
-                new CredentialsPolicy(credentials),
-                auditorPolicy);
+        final HttpPipeline pipeline = HttpPipeline.builder()
+            .httpClient(new MockHttpClient())
+            .policies(new CredentialsPolicy(credentials), auditorPolicy)
+            .build();
 
         HttpRequest request = new HttpRequest(HttpMethod.GET, new URL("http://localhost"));
         pipeline.send(request).block();