Initial implementation of Cronet Async API.

components/cronet/android/cronet_url_request_adapter.h

Index: components/cronet/android/cronet_url_request_adapter.h
diff --git a/components/cronet/android/cronet_url_request_adapter.h b/components/cronet/android/cronet_url_request_adapter.h
new file mode 100644
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+++ b/components/cronet/android/cronet_url_request_adapter.h
@@ -0,0 +1,139 @@
+// Copyright 2014 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.
+
+#ifndef COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_ADAPTER_H_
+#define COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_ADAPTER_H_
+
+#include <jni.h>
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "net/base/request_priority.h"
+#include "net/http/http_request_headers.h"
+#include "net/url_request/url_request.h"
+#include "url/gurl.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace net {
+class GrowableIOBuffer;
+class HttpResponseHeaders;
+class UploadDataStream;
+}  // namespace net
+
+namespace cronet {
+
+class CronetURLRequestContextAdapter;
+
+// An adapter from the JNI CronetUrlRequest object to the Chromium URLRequest.
+class CronetURLRequestAdapter : public net::URLRequest::Delegate {
+ public:
+  // The delegate which is called when the request_adapter finishes.
+  class CronetURLRequestAdapterDelegate
+      : public base::RefCountedThreadSafe<CronetURLRequestAdapterDelegate> {
+   public:
+    virtual void OnRedirect(const GURL& newLocation, int http_status_code) = 0;
+    virtual void OnResponseStarted(int http_status_code) = 0;
+    virtual void OnBytesRead(unsigned char* bytes_buffer,
+                             int bytes_read) = 0;
+    virtual void OnRequestFinished() = 0;
+    virtual void OnError(int error) = 0;
+
+   protected:
+    friend class base::RefCountedThreadSafe<CronetURLRequestAdapterDelegate>;
+    virtual ~CronetURLRequestAdapterDelegate() {}
+  };
+
+  CronetURLRequestAdapter(CronetURLRequestContextAdapter* context,
+                          CronetURLRequestAdapterDelegate* delegate,
+                          const GURL& url,
+                          net::RequestPriority priority);
+  ~CronetURLRequestAdapter() override;
+
+  // Sets the request method GET, POST etc.
+  void SetMethod(const std::string& method);
+
+  // Adds a header to the request before it starts.
+  void AddRequestHeader(const std::string& name, const std::string& value);
+
+  // Starts the request.
+  void Start();
+
+  // Follow redirect.

[xunjieli, 2014/10/28 14:24:19]

nit: probably we should use all third-person for consistency? eg. Follows
instead of Follow, Reads instead of Read.

[mef, 2014/10/28 16:29:00]

Done. Great suggestion!

+  void FollowDeferredRedirect();
+
+  // Read more data.
+  void ReadData();
+
+  // Releases all resources for the request and deletes the object
+  // itself.
+  void Destroy();
+
+  // Returns the URL of the request.
+  const GURL& url() const { return initial_url_; }
+
+  // Get all response headers, as a HttpResponseHeaders object.
+  net::HttpResponseHeaders* GetResponseHeaders() const;
+
+  // Returns a pointer to the downloaded data.
+  unsigned char* Data() const;
+
+  // Get NPN or ALPN Negotiated Protocol (if any) from HttpResponseInfo.
+  std::string GetNegotiatedProtocol() const;
+
+  // Returns true if response is coming from the cache.
+  bool GetWasCached() const;
+
+  // Gets the total amount of data received from network after SSL decoding and
+  // proxy handling.
+  int64 GetTotalReceivedBytes() const;
+
+  // net::URLRequest::Delegate overrides
+  void OnReceivedRedirect(net::URLRequest* request,
+                          const net::RedirectInfo& redirect_info,
+                          bool* defer_redirect) override;
+
+  void OnResponseStarted(net::URLRequest* request) override;
+
+  void OnReadCompleted(net::URLRequest* request, int bytes_read) override;
+  // Return true if currently running on network thread.
+  bool IsOnNetworkThread() const;
+
+ private:
+  void StartOnNetworkThread();
+  void FollowDeferredRedirectOnNetworkThread();
+  void ReadDataOnNetworkThread();
+  void DestroyOnNetworkThread();
+  // Check whether request was destroyed while |called_to_delegate_| and if so,
+  // then perform actual destruction and return true.
+  bool WasDestroyedWhileCalledToDelegate();
+  // Check status of the request_adapter, return true if |is_success()| is true,
+  // otherwise report error and cancel request_adapter.
+  bool CheckStatus(net::URLRequest* request);
+
+  CronetURLRequestContextAdapter* context_;
+  scoped_refptr<CronetURLRequestAdapterDelegate> delegate_;
+  GURL initial_url_;
+  net::RequestPriority initial_priority_;
+  std::string initial_method_;
+  net::HttpRequestHeaders initial_request_headers_;
+  scoped_ptr<net::URLRequest> url_request_;
+  scoped_refptr<net::IOBufferWithSize> read_buffer_;
+  bool called_to_delegate_;

[xunjieli, 2014/10/28 14:24:19]

nit: maybe add a comment to this variable? Not sure what it means from the name.

[mef, 2014/10/28 16:29:00]

Done.

+  // Set to |true| if |this| should be destroyed upon return from the delegate.
+  // Used to protect adapter from being destructed while it is accessed by
+  // delegate.
+  bool destroy_soon_;
+
+  DISALLOW_COPY_AND_ASSIGN(CronetURLRequestAdapter);
+};
+
+}  // namespace cronet
+
+#endif  // COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_ADAPTER_H_