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// Copyright (c) 2010 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/geolocation/location_arbitrator.h"
#include <map>
#include "base/logging.h"
#include "base/non_thread_safe.h"
#include "base/ref_counted.h"
#include "base/scoped_ptr.h"
#include "base/string_util.h"
#include "base/scoped_vector.h"
#include "chrome/browser/geolocation/access_token_store.h"
#include "chrome/browser/geolocation/location_provider.h"
#include "chrome/browser/profile.h"
#include "chrome/common/geoposition.h"
#include "chrome/common/net/url_request_context_getter.h"
#include "googleurl/src/gurl.h"
namespace {
const char* kDefaultNetworkProviderUrl = "https://www.google.com/loc/json";
GeolocationArbitrator* g_instance_ = NULL;
// TODO(joth): Remove this global function pointer and update all tests to use
// an injected ProviderFactory class instead.
GeolocationArbitrator::LocationProviderFactoryFunction
g_provider_factory_function_for_test = NULL;
} // namespace
// To avoid oscillations, set this to twice the expected update interval of a
// a GPS-type location provider (in case it misses a beat) plus a little.
const int64 GeolocationArbitrator::kFixStaleTimeoutMilliseconds =
11 * base::Time::kMillisecondsPerSecond;
class GeolocationArbitratorImpl
: public GeolocationArbitrator,
public LocationProviderBase::ListenerInterface,
public NonThreadSafe {
public:
GeolocationArbitratorImpl(AccessTokenStore* access_token_store,
URLRequestContextGetter* context_getter,
GetTimeNow get_time_now,
ProviderFactory* provider_factory);
virtual ~GeolocationArbitratorImpl();
// GeolocationArbitrator
virtual void AddObserver(GeolocationArbitrator::Delegate* delegate,
const UpdateOptions& update_options);
virtual bool RemoveObserver(GeolocationArbitrator::Delegate* delegate);
virtual Geoposition GetCurrentPosition();
virtual void OnPermissionGranted(const GURL& requesting_frame);
virtual bool HasPermissionBeenGranted() const;
// ListenerInterface
virtual void LocationUpdateAvailable(LocationProviderBase* provider);
void OnAccessTokenStoresLoaded(
AccessTokenStore::AccessTokenSet access_token_store);
private:
// Takes ownership of |provider| on entry; it will either be added to
// |provider_vector| or deleted on error (e.g. it fails to start).
void RegisterProvider(LocationProviderBase* provider,
ScopedVector<LocationProviderBase>* provider_vector);
void StartProviders();
// Returns true if |new_position| is an improvement over |old_position|.
// Set |from_same_provider| to true if both the positions came from the same
// provider.
bool IsNewPositionBetter(const Geoposition& old_position,
const Geoposition& new_position,
bool from_same_provider) const;
scoped_refptr<AccessTokenStore> access_token_store_;
scoped_refptr<URLRequestContextGetter> context_getter_;
GetTimeNow get_time_now_;
scoped_refptr<ProviderFactory> provider_factory_;
ScopedVector<LocationProviderBase> providers_;
typedef std::map<GeolocationArbitrator::Delegate*, UpdateOptions> DelegateMap;
DelegateMap observers_;
// The current best estimate of our position.
Geoposition position_;
// The provider which supplied the current |position_|
const LocationProviderBase* position_provider_;
GURL most_recent_authorized_frame_;
CancelableRequestConsumer request_consumer_;
};
class DefaultLocationProviderFactory
: public GeolocationArbitratorImpl::ProviderFactory {
public:
virtual LocationProviderBase* NewNetworkLocationProvider(
AccessTokenStore* access_token_store,
URLRequestContextGetter* context,
const GURL& url,
const string16& access_token) {
if (g_provider_factory_function_for_test)
return g_provider_factory_function_for_test();
return ::NewNetworkLocationProvider(access_token_store, context,
url, access_token);
}
virtual LocationProviderBase* NewGpsLocationProvider() {
if (g_provider_factory_function_for_test)
return NULL;
return ::NewGpsLocationProvider();
}
};
GeolocationArbitratorImpl::GeolocationArbitratorImpl(
AccessTokenStore* access_token_store,
URLRequestContextGetter* context_getter,
GetTimeNow get_time_now,
ProviderFactory* provider_factory)
: access_token_store_(access_token_store),
context_getter_(context_getter),
get_time_now_(get_time_now),
provider_factory_(provider_factory),
position_provider_(NULL) {
DCHECK(NULL == g_instance_);
DCHECK(GURL(kDefaultNetworkProviderUrl).is_valid());
g_instance_ = this;
access_token_store_->LoadAccessTokens(
&request_consumer_,
NewCallback(this,
&GeolocationArbitratorImpl::OnAccessTokenStoresLoaded));
}
GeolocationArbitratorImpl::~GeolocationArbitratorImpl() {
DCHECK(CalledOnValidThread());
DCHECK(observers_.empty()) << "Not all observers have unregistered";
DCHECK(this == g_instance_);
g_instance_ = NULL;
}
void GeolocationArbitratorImpl::AddObserver(
GeolocationArbitrator::Delegate* delegate,
const UpdateOptions& update_options) {
DCHECK(CalledOnValidThread());
observers_[delegate] = update_options;
StartProviders();
if (position_.IsInitialized()) {
delegate->OnLocationUpdate(position_);
}
}
bool GeolocationArbitratorImpl::RemoveObserver(
GeolocationArbitrator::Delegate* delegate) {
DCHECK(CalledOnValidThread());
size_t remove = observers_.erase(delegate);
if (observers_.empty()) {
// TODO(joth): Delayed callback to linger before stopping providers.
for (ScopedVector<LocationProviderBase>::iterator i = providers_.begin();
i != providers_.end(); ++i) {
(*i)->StopProvider();
}
} else { // The high accuracy requirement may have changed.
StartProviders();
}
return remove > 0;
}
Geoposition GeolocationArbitratorImpl::GetCurrentPosition() {
return position_;
}
void GeolocationArbitratorImpl::OnPermissionGranted(
const GURL& requesting_frame) {
DCHECK(CalledOnValidThread());
most_recent_authorized_frame_ = requesting_frame;
for (ScopedVector<LocationProviderBase>::iterator i = providers_.begin();
i != providers_.end(); ++i) {
(*i)->OnPermissionGranted(requesting_frame);
}
}
bool GeolocationArbitratorImpl::HasPermissionBeenGranted() const {
DCHECK(CalledOnValidThread());
return most_recent_authorized_frame_.is_valid();
}
void GeolocationArbitratorImpl::LocationUpdateAvailable(
LocationProviderBase* provider) {
DCHECK(CalledOnValidThread());
DCHECK(provider);
Geoposition new_position;
provider->GetPosition(&new_position);
DCHECK(new_position.IsInitialized());
if (!IsNewPositionBetter(position_, new_position,
provider == position_provider_))
return;
position_ = new_position;
position_provider_ = provider;
DelegateMap::const_iterator it = observers_.begin();
while (it != observers_.end()) {
// Advance iterator before callback to guard against synchronous unregister.
Delegate* delegate = it->first;
++it;
delegate->OnLocationUpdate(position_);
}
}
void GeolocationArbitratorImpl::OnAccessTokenStoresLoaded(
AccessTokenStore::AccessTokenSet access_token_set) {
DCHECK(providers_.empty())
<< "OnAccessTokenStoresLoaded : has existing location "
<< "provider. Race condition caused repeat load of tokens?";
// If there are no access tokens, boot strap it with the default server URL.
if (access_token_set.empty())
access_token_set[GURL(kDefaultNetworkProviderUrl)];
for (AccessTokenStore::AccessTokenSet::iterator i =
access_token_set.begin();
i != access_token_set.end(); ++i) {
RegisterProvider(
provider_factory_->NewNetworkLocationProvider(
access_token_store_.get(), context_getter_.get(),
i->first, i->second),
&providers_);
}
RegisterProvider(provider_factory_->NewGpsLocationProvider(),
&providers_);
StartProviders();
}
void GeolocationArbitratorImpl::RegisterProvider(
LocationProviderBase* provider,
ScopedVector<LocationProviderBase>* provider_vector) {
DCHECK(provider_vector);
if (!provider)
return;
provider->RegisterListener(this);
if (most_recent_authorized_frame_.is_valid())
provider->OnPermissionGranted(most_recent_authorized_frame_);
provider_vector->push_back(provider);
}
void GeolocationArbitratorImpl::StartProviders() {
DCHECK(CalledOnValidThread());
const bool high_accuracy_required =
UpdateOptions::Collapse(observers_).use_high_accuracy;
for (ScopedVector<LocationProviderBase>::iterator i = providers_.begin();
i != providers_.end(); ++i) {
(*i)->StartProvider(high_accuracy_required);
}
}
bool GeolocationArbitratorImpl::IsNewPositionBetter(
const Geoposition& old_position, const Geoposition& new_position,
bool from_same_provider) const {
// Updates location_info if it's better than what we currently have,
// or if it's a newer update from the same provider.
if (!old_position.IsValidFix()) {
// Older location wasn't locked.
return true;
}
if (new_position.IsValidFix()) {
// New location is locked, let's check if it's any better.
if (old_position.accuracy >= new_position.accuracy) {
// Accuracy is better.
return true;
} else if (from_same_provider) {
// Same provider, fresher location.
return true;
} else if ((get_time_now_() - old_position.timestamp).InMilliseconds() >
kFixStaleTimeoutMilliseconds) {
// Existing fix is stale.
return true;
}
}
return false;
}
GeolocationArbitrator* GeolocationArbitrator::Create(
AccessTokenStore* access_token_store,
URLRequestContextGetter* context_getter,
GetTimeNow get_time_now,
ProviderFactory* provider_factory) {
return new GeolocationArbitratorImpl(access_token_store, context_getter,
get_time_now, provider_factory);
}
GeolocationArbitrator* GeolocationArbitrator::GetInstance() {
if (!g_instance_) {
// Construct the arbitrator using default token store and url context. We
// get the url context getter from the default profile as it's not
// particularly important which profile it is attached to: the network
// request implementation disables cookies anyhow.
Create(NewChromePrefsAccessTokenStore(),
Profile::GetDefaultRequestContext(),
base::Time::Now,
new DefaultLocationProviderFactory);
DCHECK(g_instance_);
}
return g_instance_;
}
void GeolocationArbitrator::SetProviderFactoryForTest(
LocationProviderFactoryFunction factory_function) {
g_provider_factory_function_for_test = factory_function;
}
GeolocationArbitrator::GeolocationArbitrator() {
}
GeolocationArbitrator::~GeolocationArbitrator() {
}
GeolocationArbitrator::ProviderFactory::~ProviderFactory() {
}
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