blob: 11cf0798f246769e015c07a76e418c161a5acd35 [file] [log] [blame]
// Copyright 2018 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 "services/device/geolocation/position_cache_impl.h"
#include <algorithm>
#include "base/strings/utf_string_conversions.h"
#include "services/device/geolocation/wifi_data.h"
#include "services/device/public/mojom/geoposition.mojom.h"
namespace device {
// static
const size_t PositionCacheImpl::kMaximumSize = 10;
// static
const base::TimeDelta PositionCacheImpl::kMaximumLifetime =
base::TimeDelta::FromDays(1);
PositionCacheImpl::CacheEntry::CacheEntry(
const Hash& hash,
const mojom::Geoposition& position,
std::unique_ptr<base::OneShotTimer> eviction_timer)
: hash_(hash),
position_(position),
eviction_timer_(std::move(eviction_timer)) {}
PositionCacheImpl::CacheEntry::~CacheEntry() = default;
PositionCacheImpl::CacheEntry::CacheEntry(CacheEntry&&) = default;
PositionCacheImpl::CacheEntry& PositionCacheImpl::CacheEntry::operator=(
CacheEntry&&) = default;
// static
PositionCacheImpl::Hash PositionCacheImpl::MakeKey(const WifiData& wifi_data) {
// Currently we use only WiFi data and base the key only on the MAC addresses.
base::string16 key;
const size_t kCharsPerMacAddress = 6 * 3 + 1; // e.g. "11:22:33:44:55:66|"
key.reserve(wifi_data.access_point_data.size() * kCharsPerMacAddress);
const base::string16 separator(base::ASCIIToUTF16("|"));
for (const auto& access_point_data : wifi_data.access_point_data) {
key += separator;
key += access_point_data.mac_address;
key += separator;
}
return key;
}
PositionCacheImpl::PositionCacheImpl(const base::TickClock* clock)
: clock_(clock) {
net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
}
PositionCacheImpl::~PositionCacheImpl() {
net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
}
void PositionCacheImpl::CachePosition(const WifiData& wifi_data,
const mojom::Geoposition& position) {
const Hash key = MakeKey(wifi_data);
// If the cache is full, remove the oldest entry.
if (data_.size() == kMaximumSize)
data_.erase(data_.begin());
DCHECK_LT(data_.size(), kMaximumSize);
auto eviction_timer = std::make_unique<base::OneShotTimer>(clock_);
// Ensure that the entry we're adding will be evicted after kMaximumLifetime.
// base::Unretained safe because the timer is indirectly owned by |this|.
eviction_timer->Start(FROM_HERE, kMaximumLifetime,
base::BindOnce(&PositionCacheImpl::EvictEntry,
base::Unretained(this), key));
data_.emplace_back(key, position, std::move(eviction_timer));
}
const mojom::Geoposition* PositionCacheImpl::FindPosition(
const WifiData& wifi_data) const {
const Hash key = MakeKey(wifi_data);
auto it = std::find(data_.begin(), data_.end(), key);
return it == data_.end() ? nullptr : (it->position());
}
const mojom::Geoposition& PositionCacheImpl::GetLastUsedNetworkPosition()
const {
return last_used_position_;
}
void PositionCacheImpl::SetLastUsedNetworkPosition(
const mojom::Geoposition& position) {
last_used_position_ = position;
}
void PositionCacheImpl::OnNetworkChanged(
net::NetworkChangeNotifier::ConnectionType) {
// OnNetworkChanged is called " when a change occurs to the host
// computer's hardware or software that affects the route network packets
// take to any network server.". This means that whatever position we had
// stored for a wired connection (empty WifiData) could have become stale.
EvictEntry(MakeKey(WifiData()));
last_used_position_ = {};
}
void PositionCacheImpl::EvictEntry(const Hash& hash) {
data_.erase(std::remove(data_.begin(), data_.end(), hash), data_.end());
}
} // namespace device