Add external data use observer

chrome/browser/android/datausage/external_data_use_observer_android.cc

+// Copyright 2015 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 "chrome/browser/android/datausage/external_data_use_observer_android.h"
+
+#include "base/android/jni_string.h"
+#include "jni/ExternalDataUseObserverAndroid_jni.h"
+#include "third_party/re2/re2/re2.h"
+#include "url/gurl.h"
+
+using base::android::ConvertUTF8ToJavaString;
+
+namespace chrome {
+
+namespace android {
+
+ExternalDataUseObserverAndroid::ExternalDataUseObserverAndroid(
+    data_usage::DataUseAggregator* data_use_aggregator)
+    : data_use_aggregator_(data_use_aggregator) {
+  DCHECK(data_use_aggregator_);
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  DCHECK(j_external_data_use_observer_.is_null());

[newt (away), 2015/10/13 19:05:21]

This DCHECK is superfluous. Of course the member variable hasn't been
initialized yet -- we're still at the beginning of the constructor.

[tbansal1, 2015/10/13 21:30:21]

Done.

+  j_external_data_use_observer_.Reset(
+      Java_ExternalDataUseObserverAndroid_create(
+          env, base::android::GetApplicationContext(),
+          reinterpret_cast<intptr_t>(this)));
+  DCHECK(!j_external_data_use_observer_.is_null());
+}
+
+ExternalDataUseObserverAndroid::~ExternalDataUseObserverAndroid() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (url_patterns_.size() > 0)
+    data_use_aggregator_->RemoveObserver(this);
+}
+
+bool ExternalDataUseObserverAndroid::Matches(const GURL& gurl) const {
+  if (!gurl.is_valid() || gurl.is_empty())
+    return false;
+
+  for (size_t i = 0; i < url_patterns_.size(); ++i) {

[sclittle, 2015/10/13 19:46:56]

nit: If you change |url_patterns_| to a ScopedVector, you can just use a
range-based for loop here.

[tbansal1, 2015/10/13 21:30:21]

Done.

+    if (re2::RE2::FullMatch(gurl.spec(), *(url_patterns_.at(i))))
+      return true;
+  }
+
+  return false;
+}
+
+void ExternalDataUseObserverAndroid::OnDataUse(
+    const std::vector<data_usage::DataUse>& data_use_sequence) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!j_external_data_use_observer_.is_null());
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+
+  for (const auto& data_use : data_use_sequence) {
+    if (!Matches(data_use.url))
+      continue;
+
+    // TODO(tbansal): Use buffering to avoid frequent JNI calls.
+    std::string tag = "";  // data_use.tab_id;
+    int64_t bytes_downloaded = data_use.rx_bytes;
+    int64_t bytes_uploaded = data_use.tx_bytes;
+    Java_ExternalDataUseObserverAndroid_onDataUse(
+        env, j_external_data_use_observer_.obj(),
+        ConvertUTF8ToJavaString(env, tag).obj(), bytes_downloaded,
+        bytes_uploaded);
+  }
+}
+
+void ExternalDataUseObserverAndroid::RegisterURLRegexes(
+    const std::vector<std::string>& url_regexes) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  bool registered_as_observer = url_patterns_.size() > 0;
+  if (!registered_as_observer && url_regexes.size() > 0) {
+    registered_as_observer = true;
+    data_use_aggregator_->AddObserver(this);
+  }
+
+  url_patterns_.clear();
+
+  re2::RE2::Options options(re2::RE2::DefaultOptions);
+  options.set_case_sensitive(false);
+
+  for (const std::string& url_regex : url_regexes) {
+    if (url_regex.empty())
+      continue;
+    scoped_ptr<re2::RE2> pattern(new re2::RE2(url_regex, options));
+    if (!pattern->ok())
+      continue;
+    url_patterns_.push_back(pattern.Pass());
+  }
+
+  // Unregister as an observer if no regular expressions were received.
+  if (url_patterns_.size() == 0 && registered_as_observer)
+    data_use_aggregator_->RemoveObserver(this);
+}
+
+bool RegisterExternalDataUseObserverAndroid(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace android
+
+}  // namespace chrome