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// Copyright 2016 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/contextual_search/browser/weekly_activity_storage.h"
#include <algorithm> // std::min
#include "base/logging.h"
namespace {
// Keys for ChromePreferenceManager storage of oldest and newest week written.
const char kOldestWeekWrittenKey[] = "contextual_search_oldest_week";
const char kNewestWeekWrittenKey[] = "contextual_search_newest_week";
// Prefixes for ChromePreferenceManager storage keyed by week.
const char kClicksWeekKeyPrefix[] = "contextual_search_clicks_week_";
const char kImpressionsWeekKeyPrefix[] = "contextual_search_impressions_week_";
// Used for validation in debug build. Week numbers are > 2300 as of year 2016.
const int kReasonableMinWeek = 2000;
} // namespace
namespace contextual_search {
WeeklyActivityStorage::WeeklyActivityStorage(int weeks_needed) {
weeks_needed_ = weeks_needed;
}
WeeklyActivityStorage::~WeeklyActivityStorage() {}
int WeeklyActivityStorage::ReadClicks(int week_number) {
std::string key = GetWeekClicksKey(week_number);
return ReadInt(key);
}
void WeeklyActivityStorage::WriteClicks(int week_number, int value) {
std::string key = GetWeekClicksKey(week_number);
WriteInt(key, value);
}
int WeeklyActivityStorage::ReadImpressions(int week_number) {
std::string key = GetWeekImpressionsKey(week_number);
return ReadInt(key);
}
void WeeklyActivityStorage::WriteImpressions(int week_number, int value) {
std::string key = GetWeekImpressionsKey(week_number);
WriteInt(key, value);
}
bool WeeklyActivityStorage::HasData(int week_number) {
return ReadInt(kOldestWeekWrittenKey) <= week_number &&
ReadInt(kNewestWeekWrittenKey) >= week_number;
}
void WeeklyActivityStorage::ClearData(int week_number) {
WriteImpressions(week_number, 0);
WriteClicks(week_number, 0);
}
void WeeklyActivityStorage::AdvanceToWeek(int week_number) {
EnsureHasActivity(week_number);
}
// private
std::string WeeklyActivityStorage::GetWeekImpressionsKey(int which_week) {
return kImpressionsWeekKeyPrefix + GetWeekKey(which_week);
}
std::string WeeklyActivityStorage::GetWeekClicksKey(int which_week) {
return kClicksWeekKeyPrefix + GetWeekKey(which_week);
}
// Round-robin implementation:
// GetWeekKey and EnsureHasActivity are implemented with a round-robin
// implementation that simply recycles usage of the last N weeks, where N is
// less than weeks_needed_.
std::string WeeklyActivityStorage::GetWeekKey(int which_week) {
return std::to_string(which_week % (weeks_needed_ + 1));
}
void WeeklyActivityStorage::EnsureHasActivity(int which_week) {
DCHECK(which_week > kReasonableMinWeek);
// If still on the newest week we're done!
int newest_week = ReadInt(kNewestWeekWrittenKey);
if (newest_week == which_week)
return;
// Update the newest and oldest week written.
if (which_week > newest_week) {
WriteInt(kNewestWeekWrittenKey, which_week);
}
int oldest_week = ReadInt(kOldestWeekWrittenKey);
if (oldest_week == 0 || oldest_week > which_week)
WriteInt(kOldestWeekWrittenKey, which_week);
// Any stale weeks to update?
if (newest_week == 0)
return;
// Moved to some new week beyond the newest previously recorded.
// Since we recycle storage we must clear the new week and all that we
// may have skipped since our last access.
int weeks_to_clear = std::min(which_week - newest_week, weeks_needed_);
int week = which_week;
while (weeks_to_clear > 0) {
WriteInt(GetWeekImpressionsKey(week), 0);
WriteInt(GetWeekClicksKey(week), 0);
week--;
weeks_to_clear--;
}
}
// Storage access bottlenecks
int WeeklyActivityStorage::ReadInt(std::string storage_bucket) {
return ReadStorage(storage_bucket);
}
void WeeklyActivityStorage::WriteInt(std::string storage_bucket, int value) {
WriteStorage(storage_bucket, value);
}
} // namespace contextual_search
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