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// 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 "chrome/browser/component_updater/component_updater_resource_throttle.h"
#include "base/location.h"
#include "base/memory/weak_ptr.h"
#include "components/component_updater/component_updater_service.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/resource_controller.h"
#include "content/public/browser/resource_throttle.h"
using content::BrowserThread;
namespace component_updater {
namespace {
///////////////////////////////////////////////////////////////////////////////
// In charge of blocking url requests until the |crx_id| component has been
// updated. This class is touched solely from the IO thread. The UI thread
// can post tasks to it via weak pointers. By default the request is blocked
// unless the CrxUpdateService calls Unblock().
// The lifetime is controlled by Chrome's resource loader so the component
// updater cannot touch objects from this class except via weak pointers.
class CUResourceThrottle : public content::ResourceThrottle,
public base::SupportsWeakPtr<CUResourceThrottle> {
public:
CUResourceThrottle();
~CUResourceThrottle() override;
// Overriden from ResourceThrottle.
void WillStartRequest(bool* defer) override;
void WillRedirectRequest(const net::RedirectInfo& redirect_info,
bool* defer) override;
const char* GetNameForLogging() const override;
// Component updater calls this function via PostTask to unblock the request.
void Unblock();
typedef std::vector<base::WeakPtr<CUResourceThrottle> > WeakPtrVector;
private:
enum State { NEW, BLOCKED, UNBLOCKED };
State state_;
};
CUResourceThrottle::CUResourceThrottle() : state_(NEW) {
DCHECK_CURRENTLY_ON(BrowserThread::IO);
}
CUResourceThrottle::~CUResourceThrottle() {
DCHECK_CURRENTLY_ON(BrowserThread::IO);
}
void CUResourceThrottle::WillStartRequest(bool* defer) {
if (state_ != UNBLOCKED) {
state_ = BLOCKED;
*defer = true;
} else {
*defer = false;
}
}
void CUResourceThrottle::WillRedirectRequest(
const net::RedirectInfo& redirect_info, bool* defer) {
WillStartRequest(defer);
}
const char* CUResourceThrottle::GetNameForLogging() const {
return "ComponentUpdateResourceThrottle";
}
void CUResourceThrottle::Unblock() {
DCHECK_CURRENTLY_ON(BrowserThread::IO);
if (state_ == BLOCKED)
controller()->Resume();
state_ = UNBLOCKED;
}
void UnblockThrottleOnUIThread(base::WeakPtr<CUResourceThrottle> rt) {
BrowserThread::PostTask(BrowserThread::IO,
FROM_HERE,
base::Bind(&CUResourceThrottle::Unblock, rt));
}
} // namespace
content::ResourceThrottle* GetOnDemandResourceThrottle(
ComponentUpdateService* cus,
const std::string& crx_id) {
DCHECK_CURRENTLY_ON(BrowserThread::IO);
// We give the raw pointer to the caller, who will delete it at will
// and we keep for ourselves a weak pointer to it so we can post tasks
// from the UI thread without having to track lifetime directly.
CUResourceThrottle* rt = new CUResourceThrottle;
BrowserThread::PostTask(
BrowserThread::UI,
FROM_HERE,
base::Bind(&ComponentUpdateService::MaybeThrottle,
base::Unretained(cus),
crx_id,
base::Bind(&UnblockThrottleOnUIThread, rt->AsWeakPtr())));
return rt;
}
} // namespace component_updater
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