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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 "net/proxy/polling_proxy_config_service.h"
#include "base/lock.h"
#include "base/message_loop_proxy.h"
#include "base/observer_list.h"
#include "base/scoped_ptr.h"
#include "base/worker_pool.h"
#include "net/proxy/proxy_config.h"
namespace net {
// Reference-counted wrapper that does all the work (needs to be
// reference-counted since we post tasks between threads; may outlive
// the parent PollingProxyConfigService).
class PollingProxyConfigService::Core
: public base::RefCountedThreadSafe<PollingProxyConfigService::Core> {
public:
Core(base::TimeDelta poll_interval,
GetConfigFunction get_config_func)
: get_config_func_(get_config_func),
has_config_(false),
poll_task_outstanding_(false),
poll_interval_(poll_interval),
have_initialized_origin_loop_(false) {
}
// Called when the parent PollingProxyConfigService is destroyed
// (observers should not be called past this point).
void Orphan() {
AutoLock l(lock_);
origin_loop_proxy_ = NULL;
}
bool GetLatestProxyConfig(ProxyConfig* config) {
LazyInitializeOriginLoop();
DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
OnLazyPoll();
// If we have already retrieved the proxy settings (on worker thread)
// then return what we last saw.
if (has_config_) {
*config = last_config_;
return true;
}
return false;
}
void AddObserver(Observer* observer) {
LazyInitializeOriginLoop();
DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
observers_.AddObserver(observer);
}
void RemoveObserver(Observer* observer) {
DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
observers_.RemoveObserver(observer);
}
// Check for a new configuration if enough time has elapsed.
void OnLazyPoll() {
LazyInitializeOriginLoop();
DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
if (poll_task_outstanding_)
return; // Still waiting for earlier test to finish.
base::TimeTicks now = base::TimeTicks::Now();
if (last_poll_time_.is_null() ||
(now - last_poll_time_) > poll_interval_) {
last_poll_time_ = now;
poll_task_outstanding_ = true;
WorkerPool::PostTask(
FROM_HERE,
NewRunnableMethod(
this, &Core::PollOnWorkerThread, get_config_func_), true);
}
}
private:
void PollOnWorkerThread(GetConfigFunction func) {
ProxyConfig config;
func(&config);
AutoLock l(lock_);
if (origin_loop_proxy_) {
origin_loop_proxy_->PostTask(
FROM_HERE,
NewRunnableMethod(this, &Core::GetConfigCompleted, config));
}
}
// Called after the worker thread has finished retrieving a configuration.
void GetConfigCompleted(const ProxyConfig& config) {
DCHECK(poll_task_outstanding_);
poll_task_outstanding_ = false;
if (!origin_loop_proxy_)
return; // Was orphaned (parent has already been destroyed).
DCHECK(origin_loop_proxy_->BelongsToCurrentThread());
if (!has_config_ || !last_config_.Equals(config)) {
// If the configuration has changed, notify the observers.
has_config_ = true;
last_config_ = config;
FOR_EACH_OBSERVER(Observer, observers_, OnProxyConfigChanged(config));
}
}
void LazyInitializeOriginLoop() {
// TODO(eroman): Really this should be done in the constructor, but right
// now chrome is constructing the ProxyConfigService on the
// UI thread so we can't cache the IO thread for the purpose
// of DCHECKs until the first call is made.
if (!have_initialized_origin_loop_) {
origin_loop_proxy_ = base::MessageLoopProxy::CreateForCurrentThread();
have_initialized_origin_loop_ = true;
}
}
GetConfigFunction get_config_func_;
ObserverList<Observer> observers_;
bool has_config_;
bool poll_task_outstanding_;
ProxyConfig last_config_;
base::TimeTicks last_poll_time_;
base::TimeDelta poll_interval_;
bool have_initialized_origin_loop_;
Lock lock_;
scoped_refptr<base::MessageLoopProxy> origin_loop_proxy_;
};
PollingProxyConfigService::PollingProxyConfigService(
base::TimeDelta poll_interval,
GetConfigFunction get_config_func)
: core_(new Core(poll_interval, get_config_func)) {
}
PollingProxyConfigService::~PollingProxyConfigService() {
core_->Orphan();
}
void PollingProxyConfigService::AddObserver(Observer* observer) {
core_->AddObserver(observer);
}
void PollingProxyConfigService::RemoveObserver(Observer* observer) {
core_->RemoveObserver(observer);
}
bool PollingProxyConfigService::GetLatestProxyConfig(ProxyConfig* config) {
return core_->GetLatestProxyConfig(config);
}
void PollingProxyConfigService::OnLazyPoll() {
core_->OnLazyPoll();
}
} // namespace net
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