Update data reduction proxy statistics prefs less often on desktop

components/data_reduction_proxy/browser/data_reduction_proxy_statistics_prefs.cc

Index: components/data_reduction_proxy/browser/data_reduction_proxy_statistics_prefs.cc
diff --git a/components/data_reduction_proxy/browser/data_reduction_proxy_statistics_prefs.cc b/components/data_reduction_proxy/browser/data_reduction_proxy_statistics_prefs.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a0e4b40147b9a14ff4b033d5cae4f78d7682f343
--- /dev/null
+++ b/components/data_reduction_proxy/browser/data_reduction_proxy_statistics_prefs.cc
@@ -0,0 +1,162 @@
+// 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/data_reduction_proxy/browser/data_reduction_proxy_statistics_prefs.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/prefs/pref_service.h"
+#include "base/prefs/scoped_user_pref_update.h"
+#include "base/sequenced_task_runner.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/task/cancelable_task_tracker.h"
+#include "base/time/time.h"
+#include "base/values.h"
+
+namespace data_reduction_proxy {
+
+DataReductionProxyStatisticsPrefs::DataReductionProxyStatisticsPrefs(
+    PrefService* prefs,
+    scoped_refptr<base::SequencedTaskRunner> task_runner,
+    base::TimeDelta delay)
+    : pref_service_(prefs),
+      task_runner_(task_runner),
+      weak_factory_(this),
+      delay_(delay),
+      delayed_task_posted_(false){
+  DCHECK(prefs);
+  DCHECK(delay >= base::TimeDelta());
+}
+
+DataReductionProxyStatisticsPrefs::~DataReductionProxyStatisticsPrefs() {
+  WritePrefs();
+}
+
+void DataReductionProxyStatisticsPrefs::Init() {

[bengr, 2014/08/27 04:53:25]

Add a comment in data_reduction_proxy_prefs to remember to update this list with
any new statistics prefs.

[megjablon, 2014/08/28 20:44:07]

Done.

+  if (delay_ != base::TimeDelta()) {
+    //Init all int64 prefs
+    InitInt64Pref(data_reduction_proxy::prefs::
+                  kDailyHttpContentLengthLastUpdateDate);
+    InitInt64Pref(data_reduction_proxy::prefs::kHttpReceivedContentLength);
+    InitInt64Pref(data_reduction_proxy::prefs::kHttpOriginalContentLength);
+
+    //Init all list prefs
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyContentLengthHttpsWithDataReductionProxyEnabled);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyContentLengthLongBypassWithDataReductionProxyEnabled);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyContentLengthShortBypassWithDataReductionProxyEnabled);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyContentLengthUnknownWithDataReductionProxyEnabled);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyContentLengthViaDataReductionProxy);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyContentLengthWithDataReductionProxyEnabled);
+    InitListPref(data_reduction_proxy::prefs::kDailyHttpOriginalContentLength);
+    InitListPref(data_reduction_proxy::prefs::kDailyHttpReceivedContentLength);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyOriginalContentLengthViaDataReductionProxy);
+    InitListPref(data_reduction_proxy::prefs::
+                 kDailyOriginalContentLengthWithDataReductionProxyEnabled);
+  }
+}
+
+void DataReductionProxyStatisticsPrefs::InitInt64Pref(const char* pref){
+  int64 pref_value = pref_service_->GetInt64(pref);
+  pref_map_[pref] = pref_value;
+}
+
+void DataReductionProxyStatisticsPrefs::InitListPref(const char* pref){
+  scoped_ptr<base::ListValue> pref_value = scoped_ptr<base::ListValue>(
+      pref_service_->GetList(pref)->DeepCopy());
+  list_pref_map_.add(pref, pref_value.Pass());
+  // need to switch ListValues to scoped_ptr to avoid memory leak

[bengr, 2014/08/27 04:53:25]

They are already, right? Explain.

[megjablon, 2014/08/28 20:44:07]

Whoops ya I forgot to move comment.

+}
+
+int64 DataReductionProxyStatisticsPrefs::GetInt64(const char* pref_path) {
+  if (delay_ == base::TimeDelta())
+    return pref_service_->GetInt64(pref_path);
+
+  DataReductionProxyPrefMap::iterator iter = pref_map_.find(pref_path);

[bengr, 2014/08/27 04:53:25]

Can't you just return pref_map_[pref_path] ? Or are you worried that pref_path
might not be a pref name tracked by this class? If the latter, you should
probably check that you find something.

[megjablon, 2014/08/28 20:44:07]

This method can't be const if the [] operator is used on a map.

+  return iter->second;
+}
+
+void DataReductionProxyStatisticsPrefs::SetInt64(const char* pref_path,
+                                                 int64 pref_value) {
+  if (delay_ == base::TimeDelta()) {
+    pref_service_->SetInt64(pref_path, pref_value);
+    return;
+  }
+
+  if (!delayed_task_posted_)
+    WritePrefsAndPost();
+  pref_map_[pref_path] = pref_value;
+}
+
+base::ListValue* DataReductionProxyStatisticsPrefs::GetList(
+    const char* pref_path) {
+  if (delay_ == base::TimeDelta()) {
+    return ListPrefUpdate(pref_service_, pref_path).Get();
+  }
+
+  if (!delayed_task_posted_)
+    WritePrefsAndPost();
+  return list_pref_map_.get(pref_path);
+}
+
+void DataReductionProxyStatisticsPrefs::WritePrefs() {
+  for (DataReductionProxyPrefMap::iterator iter = pref_map_.begin();
+       iter != pref_map_.end(); ++iter) {
+    pref_service_->SetInt64(iter->first, iter->second);
+  }
+
+  for (DataReductionProxyListPrefMap::iterator iter = list_pref_map_.begin();
+       iter != list_pref_map_.end(); ++iter) {
+    TransferList(*(iter->second),
+                 ListPrefUpdate(pref_service_, iter->first).Get());
+  }
+}
+
+void DataReductionProxyStatisticsPrefs::WritePrefsAndPost() {
+  // Only write after the first time posting the task

[bengr, 2014/08/27 04:53:25]

task.

[megjablon, 2014/08/28 20:44:07]

Done.

+  if (!delayed_task_posted_) {

[bengr, 2014/08/27 04:53:25]

if (delayed_task_posted_)
  WritePrefs();
else
  delayed_task_posted_ = true;

[megjablon, 2014/08/28 20:44:07]

Done.

+    delayed_task_posted_ = true;
+  } else {
+    WritePrefs();
+  }
+
+  task_runner_->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&DataReductionProxyStatisticsPrefs::WritePrefsAndPost,
+                 weak_factory_.GetWeakPtr()),
+                 delay_);
+}
+
+void DataReductionProxyStatisticsPrefs::TransferList(
+    const base::ListValue& from_list,
+    base::ListValue* to_list) {
+  to_list->Clear();
+  for (size_t i = 0; i < from_list.GetSize(); ++i) {
+    to_list->Set(i, new base::StringValue(base::Int64ToString(
+        GetListPrefInt64Value(from_list, i))));
+  }
+}
+
+int64 DataReductionProxyStatisticsPrefs::GetListPrefInt64Value(
+    const base::ListValue& list,
+    size_t index) {
+  std::string string_value;
+  if (!list.GetString(index, &string_value)) {
+    NOTREACHED();
+    return 0;
+  }
+
+  int64 value = 0;
+  bool rv = base::StringToInt64(string_value, &value);
+  DCHECK(rv);
+  return value;
+}
+
+} // namespace data_reduction_proxy