Initial implementation of Cronet Async API.

components/cronet/android/cronet_url_request_context.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 "components/cronet/android/cronet_url_request_context.h"
+
+#include <string>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/json/json_reader.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/metrics/statistics_recorder.h"
+#include "base/values.h"
+#include "components/cronet/android/cronet_url_request.h"
+#include "components/cronet/android/cronet_url_request_adapter.h"
+#include "components/cronet/android/cronet_url_request_context_adapter.h"
+#include "components/cronet/url_request_context_config.h"
+#include "jni/CronetUrlRequestContext_jni.h"
+
+namespace {
+
+void initJavaNetworkThread(jobject jowner) {
+  JNIEnv* jenv = base::android::AttachCurrentThread();
+  cronet::Java_CronetUrlRequestContext_initNetworkThread(jenv, jowner);
+  jenv->DeleteGlobalRef(jowner);
+}
+
+}  // namespace
+
+namespace cronet {
+
+// Explicitly register static JNI functions.
+bool CronetUrlRequestContextRegisterJni(JNIEnv* jenv) {
+  return RegisterNativesImpl(jenv);
+}
+
+// Sets global user-agent to be used for all subsequent requests.
+static jlong CreateRequestContextAdapter(JNIEnv* jenv,
+                                         jobject jcaller,
+                                         jobject japp_context,
+                                         jint jlog_level,
+                                         jstring jconfig) {
+  std::string config_string =
+      base::android::ConvertJavaStringToUTF8(jenv, jconfig);
+
+  scoped_ptr<base::Value> config_value(base::JSONReader::Read(config_string));
+  if (!config_value || !config_value->IsType(base::Value::TYPE_DICTIONARY)) {
+    DLOG(ERROR) << "Bad JSON: " << config_string;
+    return 0;
+  }
+
+  scoped_ptr<URLRequestContextConfig> context_config(
+      new URLRequestContextConfig());
+  base::JSONValueConverter<URLRequestContextConfig> converter;
+  if (!converter.Convert(*config_value, context_config.get())) {
+    DLOG(ERROR) << "Bad Config: " << config_value;
+    return 0;
+  }
+
+  // Set application context.
+  base::android::ScopedJavaLocalRef<jobject> scoped_context(jenv, japp_context);
+  base::android::InitApplicationContext(jenv, scoped_context);
+
+  // TODO(mef): MinLogLevel is global, shared by all URLRequestContexts.
+  // Revisit this if each URLRequestContext would need an individual log level.
+  logging::SetMinLogLevel(static_cast<int>(jlog_level));

[mmenke, 2014/10/31 15:49:22]

Suggestion:  Don't take this on context creation, make it a static method
instead.  Makes it clear its a global, and can have documentation that it
affects existing contexts as well as new ones.

[mef, 2014/10/31 20:39:15]

Done.

+
+  CronetURLRequestContextAdapter* context_adapter =
+      new CronetURLRequestContextAdapter();
+  base::Closure init_java_network_thread = base::Bind (

[mmenke, 2014/10/31 15:49:22]

nit:  Remove space before open paren.

[mef, 2014/10/31 20:39:15]

Done.

+      &initJavaNetworkThread,
+      jenv->NewGlobalRef(jcaller));

[mmenke, 2014/10/31 15:49:22]

Can we used a scoped java ref here?  Does, admittedly, result in grabbing
references twice, but prefer to avoid naked pointers and the Java equivalent to
minimize the risk of leaks, particularly given the lack of testing we have for
them.

[mef, 2014/10/31 20:39:15]

Acknowledged. We probably can, but I'm not sure how to pass it correctly.

[mmenke, 2014/10/31 21:03:24]

Think you just pass it as a ScopedJavaGlobalRef (Or const ScopedJavaGlobalRef&,
to avoid an extra increment/decrements)

So it'd look like:

ScopedJavaGlobalRef blah;
blah.Reset(env, jcaller);

...base::Bind(..., blah);

[mef, 2014/10/31 21:43:15]

Done.

+  context_adapter->Initialize(context_config.Pass(), init_java_network_thread);
+
+  return reinterpret_cast<jlong>(context_adapter);
+}
+
+// Destroys native objects.
+static void DestroyRequestContextAdapter(JNIEnv* jenv,
+                                         jobject jcaller,
+                                         jlong jurl_request_context_adapter) {
+  if (jurl_request_context_adapter == 0)
+    return;
+  CronetURLRequestContextAdapter* context_adapter =
+      reinterpret_cast<CronetURLRequestContextAdapter*>(
+          jurl_request_context_adapter);
+  context_adapter->Destroy();
+}
+
+// Starts recording statistics.
+static void InitializeStatistics(JNIEnv* jenv, jobject jcaller) {
+  base::StatisticsRecorder::Initialize();
+}
+
+// Gets current statistics with |filter| as a substring as JSON text (an empty
+// |filter| will include all registered histograms).
+static jstring GetStatisticsJSON(JNIEnv* jenv,
+                                 jobject jcaller,
+                                 jstring jfilter) {
+  std::string query = base::android::ConvertJavaStringToUTF8(jenv, jfilter);
+  std::string json = base::StatisticsRecorder::ToJSON(query);
+  return base::android::ConvertUTF8ToJavaString(jenv, json).Release();
+}
+
+// Starts recording NetLog into file with |fileName|.
+static void StartNetLogToFile(JNIEnv* jenv,
+                              jobject jcaller,
+                              jlong jurl_request_context_adapter,
+                              jstring fileName) {
+  if (jurl_request_context_adapter == 0)
+    return;
+  CronetURLRequestContextAdapter* context_adapter =
+      reinterpret_cast<CronetURLRequestContextAdapter*>(
+          jurl_request_context_adapter);
+  std::string file_name =
+      base::android::ConvertJavaStringToUTF8(jenv, fileName);
+  context_adapter->StartNetLogToFile(file_name);
+}
+
+// Stops recording NetLog.
+static void StopNetLog(JNIEnv* jenv,
+                       jobject jcaller,
+                       jlong jurl_request_context_adapter) {
+  if (jurl_request_context_adapter == 0)
+    return;
+  CronetURLRequestContextAdapter* context_adapter =
+      reinterpret_cast<CronetURLRequestContextAdapter*>(
+          jurl_request_context_adapter);
+  context_adapter->StopNetLog();
+}
+
+}  // namespace cronet