blob: b1adaca3a399d57fee8522934ad48386023cc4fa [file] [log] [blame]
// Copyright (c) 2012 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 "content/common/content_export.h"
namespace net {
struct RedirectInfo;
namespace content {
class AsyncRevalidationDriver;
class ResourceController;
class ThrottlingResourceHandler;
// A ResourceThrottle gets notified at various points during the process of
// loading a resource. At each stage, it has the opportunity to defer the
// resource load. The ResourceController interface may be used to resume a
// deferred resource load, or it may be used to cancel a resource load at any
// time.
class CONTENT_EXPORT ResourceThrottle {
// An interface to get notified when the throttle implementation considers
// it's ready to resume the deferred resource load. The throttle
// implementation may also tell the delegate to cancel the resource loading.
class CONTENT_EXPORT Delegate {
// Cancels the resource load.
virtual void Cancel() = 0;
// Cancels the resource load with the specified error code.
virtual void CancelWithError(int error_code) = 0;
// Tells the delegate to resume the deferred resource load.
virtual void Resume() = 0;
virtual ~Delegate() {}
virtual ~ResourceThrottle() {}
// Called before the resource request is started.
virtual void WillStartRequest(bool* defer) {}
// Called when the request was redirected. |redirect_info| contains the
// redirect responses's HTTP status code and some information about the new
// request that will be sent if the redirect is followed, including the new
// URL and new method.
virtual void WillRedirectRequest(const net::RedirectInfo& redirect_info,
bool* defer) {}
// Called when the response headers and meta data are available.
virtual void WillProcessResponse(bool* defer) {}
// Returns the name of the throttle, as a UTF-8 C-string, for logging
// purposes. nullptr is not allowed. Caller does *not* take ownership of the
// returned string.
virtual const char* GetNameForLogging() const = 0;
// Whether this ResourceThrottle needs to execute WillProcessResponse before
// any part of the response body is read. Normally this is false. This should
// be set to true if the ResourceThrottle wants to ensure that no part of the
// response body will be cached if the request is canceled in
// WillProcessResponse.
virtual bool MustProcessResponseBeforeReadingBody();
void set_delegate_for_testing(Delegate* delegate) { delegate_ = delegate; }
ResourceThrottle() : delegate_(nullptr) {}
// Helper methods for subclasses. When these methods are called, methods with
// the same name on |delegate_| are called.
void Cancel();
void CancelWithError(int error_code);
void Resume();
friend class AsyncRevalidationDriver;
friend class ThrottlingResourceHandler;
void set_delegate(Delegate* delegate) { delegate_ = delegate; }
Delegate* delegate_;
} // namespace content