Cronet API Refactoring

components/cronet/android/java/src/org/chromium/net/impl/CronetEngineBase.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+package org.chromium.net.impl;
+
+import android.support.annotation.IntDef;
+
+import static org.chromium.net.UrlRequest.Builder.REQUEST_PRIORITY_HIGHEST;
+import static org.chromium.net.UrlRequest.Builder.REQUEST_PRIORITY_IDLE;
+import static org.chromium.net.UrlRequest.Builder.REQUEST_PRIORITY_LOW;
+import static org.chromium.net.UrlRequest.Builder.REQUEST_PRIORITY_LOWEST;
+import static org.chromium.net.UrlRequest.Builder.REQUEST_PRIORITY_MEDIUM;
+
+import org.chromium.net.BidirectionalStream;
+import org.chromium.net.ExperimentalBidirectionalStream;
+import org.chromium.net.ExperimentalCronetEngine;
+import org.chromium.net.ExperimentalUrlRequest;
+import org.chromium.net.UrlRequest;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.net.URL;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Executor;
+
+/**
+ * Base class of {@link CronetUrlRequestContext} and {@link JavaCronetEngine} that contains
+ * shared logic.
+ */
+public abstract class CronetEngineBase extends ExperimentalCronetEngine {
+    /**
+     * Creates a {@link UrlRequest} object. All callbacks will
+     * be called on {@code executor}'s thread. {@code executor} must not run
+     * tasks on the current thread to prevent blocking networking operations
+     * and causing exceptions during shutdown.
+     *
+     * @param url {@link URL} for the request.
+     * @param callback callback object that gets invoked on different events.
+     * @param executor {@link Executor} on which all callbacks will be invoked.
+     * @param priority priority of the request which should be one of the
+     *         {@link UrlRequest.Builder#REQUEST_PRIORITY_IDLE REQUEST_PRIORITY_*}
+     *         values.
+     * @param requestAnnotations Objects to pass on to
+     *        {@link org.chromium.net.RequestFinishedInfo.Listener}.
+     * @param disableCache disables cache for the request.
+     *         If context is not set up to use cache this param has no effect.
+     * @param disableConnectionMigration disables connection migration for this
+     *         request if it is enabled for the session.
+     * @param allowDirectExecutor whether executors used by this request are permitted
+     *         to execute submitted tasks inline.
+     * @return new request.
+     */
+    protected abstract UrlRequestBase createRequest(String url, UrlRequest.Callback callback,
+            Executor executor, int priority, Collection<Object> requestAnnotations,

[pauljensen, 2016/10/03 15:22:37]

@RequestPriority?

[kapishnikov, 2016/10/03 23:49:28]

I am actually getting a lint error if I do so:

------
/tmp/tmpKBxsvT/SRC_ROOT1/components/cronet/android/java/src/org/chromium/net/impl/UrlRequestBuilderImpl.java:174
Must be one of: 0, 1, 2, 3, 4: WrongConstant [warning]
                mPriority, mRequestAnnotations, mDisableCache,
mDisableConnectionMigration,
                ~~~~~~~~~
-----

Both mPriority and the input parameter are annotated with the same
@RequestPriority annotation. Need to figure it out.

[kapishnikov, 2016/10/05 17:16:31]

Done but had to add @SuppressLint("WrongConstant").

+            boolean disableCache, boolean disableConnectionMigration, boolean allowDirectExecutor);
+
+    /**
+     * Creates a {@link BidirectionalStream} object. {@code callback} methods will
+     * be invoked on {@code executor}. {@code executor} must not run
+     * tasks on the current thread to prevent blocking networking operations
+     * and causing exceptions during shutdown.
+     *
+     * @param url the URL for the stream
+     * @param callback the object whose methods get invoked upon different events
+     * @param executor the {@link Executor} on which all callbacks will be called
+     * @param httpMethod the HTTP method to use for the stream
+     * @param requestHeaders the list of request headers
+     * @param priority priority of the stream which should be one of the
+     *         {@link BidirectionalStream.Builder#STREAM_PRIORITY_IDLE STREAM_PRIORITY_*}
+     *         values.
+     * @param delayRequestHeadersUntilFirstFlush whether to delay sending request
+     *         headers until flush() is called, and try to combine them
+     *         with the next data frame.
+     * @param requestAnnotations Objects to pass on to
+     *       {@link org.chromium.net.RequestFinishedInfo.Listener}.
+     * @return a new stream.
+     */
+    public abstract ExperimentalBidirectionalStream createBidirectionalStream(String url,

[pauljensen, 2016/10/03 15:22:37]

how come this is public but createRequest() is protected?  override of
createBidiStream looks to be public

[kapishnikov, 2016/10/03 23:49:28]

Good catch. Changed to 'protected'.

+            BidirectionalStream.Callback callback, Executor executor, String httpMethod,
+            List<Map.Entry<String, String>> requestHeaders,
+            @BidirectionalStreamBuilderImpl.StreamPriority int priority,
+            boolean delayRequestHeadersUntilFirstFlush, Collection<Object> requestAnnotations);
+
+    /**
+     * @return {@code true} if the engine is enabled.
+     */
+    public abstract boolean isEnabled();

[pauljensen, 2016/10/03 15:22:37]

is this used anymore?  can we get rid of it and the overrides?

[kapishnikov, 2016/10/03 23:49:28]

Another good catch. It is not used anymore.

+
+    @Override
+    public ExperimentalUrlRequest.Builder newUrlRequestBuilder(
+            String url, UrlRequest.Callback callback, Executor executor) {
+        return new UrlRequestBuilderImpl(url, callback, executor, this);
+    }
+
+    @IntDef({
+            REQUEST_PRIORITY_IDLE, REQUEST_PRIORITY_LOWEST, REQUEST_PRIORITY_LOW,
+            REQUEST_PRIORITY_MEDIUM, REQUEST_PRIORITY_HIGHEST,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface RequestPriority {}
+}