Initial implementation of Cronet Async API.

components/cronet/android/cronet_url_request_adapter.cc

+// 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.
+
+#include "cronet_url_request_adapter.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "components/cronet/android/cronet_url_request_context_adapter.h"
+#include "components/cronet/android/wrapped_channel_upload_element_reader.h"
+#include "net/base/io_buffer.h"
+#include "net/base/load_flags.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/redirect_info.h"
+#include "net/url_request/url_request_context.h"
+
+namespace cronet {
+
+static const size_t kBufferSizeIncrement = 32768;
+
+CronetURLRequestAdapter::CronetURLRequestAdapter(
+    CronetURLRequestContextAdapter* context,
+    CronetURLRequestAdapterDelegate* delegate,
+    GURL url,
+    net::RequestPriority priority)
+    : method_("GET"),
+      read_buffer_(new net::IOBufferWithSize(kBufferSizeIncrement)),
+      http_status_code_(0),
+      called_to_delegate_(false),
+      cancel_soon_(false) {

[xunjieli, 2014/10/22 21:02:16]

nit: Not exactly sure what cancel_soon_ does from its name. Could you add a
comment in the header file? 

[mef, 2014/10/24 03:31:42]

Done.

+  context_ = context;
+  delegate_ = delegate;
+  url_ = url;
+  priority_ = priority;
+}
+
+CronetURLRequestAdapter::~CronetURLRequestAdapter() {
+  url_request_.reset();
+}
+
+void CronetURLRequestAdapter::SetMethod(const std::string& method) {
+  method_ = method;
+}
+
+void CronetURLRequestAdapter::AddRequestHeader(const std::string& name,
+                                               const std::string& value) {
+  request_headers_.SetHeader(name, value);
+}
+
+net::HttpResponseHeaders* CronetURLRequestAdapter::GetResponseHeaders() const {
+  DCHECK(IsOnNetworkThread());
+  if (url_request_ == NULL)
+    return NULL;
+  return url_request_->response_headers();
+}
+
+std::string CronetURLRequestAdapter::GetNegotiatedProtocol() const {
+  DCHECK(IsOnNetworkThread());
+  if (url_request_ == NULL)
+    return std::string();
+  return url_request_->response_info().npn_negotiated_protocol;
+}
+
+bool CronetURLRequestAdapter::GetWasCached() const {
+  DCHECK(IsOnNetworkThread());
+  if (url_request_ == NULL)
+    return false;
+  return url_request_->response_info().was_cached;
+}
+
+int64 CronetURLRequestAdapter::GetTotalReceivedBytes() const {
+  DCHECK(IsOnNetworkThread());
+  if (url_request_ == NULL)
+    return 0;
+  return url_request_->GetTotalReceivedBytes();
+}
+
+void CronetURLRequestAdapter::Start() {
+  DCHECK(!IsOnNetworkThread());
+  context_->GetNetworkTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&CronetURLRequestAdapter::StartOnNetworkThread,
+                 base::Unretained(this)));
+}
+
+void CronetURLRequestAdapter::FollowDeferredRedirect() {
+  DCHECK(!IsOnNetworkThread());
+  context_->GetNetworkTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &CronetURLRequestAdapter::FollowDeferredRedirectOnNetworkThread,
+          base::Unretained(this)));
+}
+
+// Receive more data.
+void CronetURLRequestAdapter::ReadData() {
+  DCHECK(!IsOnNetworkThread());
+  context_->GetNetworkTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&CronetURLRequestAdapter::ReadDataOnNetworkThread,
+                 base::Unretained(this)));
+}
+
+void CronetURLRequestAdapter::Cancel() {
+  DCHECK(!IsOnNetworkThread());
+  context_->GetNetworkTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&CronetURLRequestAdapter::CancelOnNetworkThread,
+                 base::Unretained(this)));
+}
+
+void CronetURLRequestAdapter::Destroy() {
+  DCHECK(!IsOnNetworkThread());
+  context_->GetNetworkTaskRunner()->DeleteSoon(FROM_HERE, this);
+}
+
+// net::URLRequest::Delegate overrides (called on network thread).
+void CronetURLRequestAdapter::OnReceivedRedirect(
+    net::URLRequest* request,
+    const net::RedirectInfo& redirect_info,
+    bool* defer_redirect) {
+  DCHECK(request->status().is_success());
+  called_to_delegate_ = true;
+  delegate_->OnRedirect(this, redirect_info.new_url);
+  *defer_redirect = true;
+}
+
+void CronetURLRequestAdapter::OnResponseStarted(net::URLRequest* request) {
+  if (!CheckStatus(request))
+    return;
+  http_status_code_ = request->GetResponseCode();

[mmenke, 2014/10/23 16:26:00]

Think it's simpler to pass this in to the delegate instead - keep the number of
accessors down a bit.

[mef, 2014/10/24 03:31:43]

Ack. Not sure how it helps, but I'll think about it.

[mmenke, 2014/10/24 03:46:19]

How it helps:  One less accessor method, one less class variable with weird
properties (It's the status code of the most recently received response - I'd
really like to get rid of all variables in the adapter that do that, just a bit
less complexity)

+  called_to_delegate_ = true;
+  delegate_->OnResponseStarted(this);
+}
+
+void CronetURLRequestAdapter::OnReadCompleted(net::URLRequest* request,
+                                              int bytes_read) {
+  if (!CheckStatus(request))
+    return;
+  called_to_delegate_ = true;
+  if (bytes_read != 0) {
+    delegate_->OnBytesRead(this, bytes_read);
+  } else {
+    delegate_->OnRequestFinished(this);
+  }
+}
+bool CronetURLRequestAdapter::IsOnNetworkThread() const {
+  return context_->GetNetworkTaskRunner()->BelongsToCurrentThread();
+}
+
+void CronetURLRequestAdapter::StartOnNetworkThread() {
+  DCHECK(IsOnNetworkThread());
+  if (cancel_soon_)
+    return;
+
+  VLOG(1) << "Starting chromium request: "
+          << url_.possibly_invalid_spec().c_str()
+          << " priority: " << RequestPriorityToString(priority_);
+  url_request_ = context_->GetURLRequestContext()->CreateRequest(
+      url_, net::DEFAULT_PRIORITY, this, NULL);
+  url_request_->SetLoadFlags(net::LOAD_DISABLE_CACHE |
+                             net::LOAD_DO_NOT_SAVE_COOKIES |
+                             net::LOAD_DO_NOT_SEND_COOKIES);
+  url_request_->set_method(method_);
+  url_request_->SetExtraRequestHeaders(request_headers_);
+  if (!request_headers_.HasHeader(net::HttpRequestHeaders::kUserAgent)) {
+    std::string user_agent;
+    user_agent = context_->GetUserAgent(url_);
+    url_request_->SetExtraRequestHeaderByName(
+        net::HttpRequestHeaders::kUserAgent, user_agent, true /* override */);
+  }
+
+  url_request_->SetPriority(priority_);
+  url_request_->Start();
+}
+
+void CronetURLRequestAdapter::FollowDeferredRedirectOnNetworkThread() {
+  DCHECK(IsOnNetworkThread());
+  if (WasCanceledWhileCalledToDelegate())
+    return;
+
+  url_request_->FollowDeferredRedirect();
+}
+
+// Reads all available data or starts an asynchronous read.
+void CronetURLRequestAdapter::ReadDataOnNetworkThread() {
+  DCHECK(IsOnNetworkThread());
+  if (WasCanceledWhileCalledToDelegate())
+    return;
+  int bytes_read = 0;
+  // If read completes synchronously, pass data to delegate.
+  if (url_request_->Read(
+          read_buffer_.get(), read_buffer_->size(), &bytes_read)) {
+    OnReadCompleted(url_request_.get(), bytes_read);
+  } else if (url_request_->status().status() !=
+             net::URLRequestStatus::IO_PENDING) {
+    OnReadCompleted(url_request_.get(), -1);
+  }
+}
+
+void CronetURLRequestAdapter::CancelOnNetworkThread() {
+  DCHECK(IsOnNetworkThread());
+  VLOG(1) << "Cancelling chromium request: " << url_.possibly_invalid_spec();
+
+  if (called_to_delegate_) {
+    cancel_soon_ = true;
+    return;
+  }
+
+  if (url_request_ != NULL)
+    url_request_->Cancel();
+
+  delegate_->OnRequestCanceled(this);
+}
+
+bool CronetURLRequestAdapter::WasCanceledWhileCalledToDelegate() {
+  DCHECK(IsOnNetworkThread());
+  DCHECK(called_to_delegate_);
+  called_to_delegate_ = false;
+  if (cancel_soon_) {
+    CancelOnNetworkThread();
+    return true;
+  }
+  return false;
+}
+
+bool CronetURLRequestAdapter::CheckStatus(net::URLRequest* request) {
+  DCHECK_NE(net::URLRequestStatus::IO_PENDING, url_request_->status().status());
+  DCHECK_EQ(request, url_request_);
+  if (url_request_->status().is_success())
+    return true;
+  VLOG(1) << "Error " << url_request_->status().error()
+          << " on chromium request: " << url_.possibly_invalid_spec();
+  called_to_delegate_ = true;
+  delegate_->OnError(this, url_request_->status().error());
+  return false;
+}
+
+unsigned char* CronetURLRequestAdapter::Data() const {
+  return reinterpret_cast<unsigned char*>(read_buffer_->data());
+}
+
+}  // namespace cronet