// Copyright (c) 2011 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.
#ifndef NET_BASE_NETWORK_DELEGATE_H_
#define NET_BASE_NETWORK_DELEGATE_H_
#pragma once
#include "base/threading/non_thread_safe.h"
#include "net/base/completion_callback.h"
class GURL;
namespace net {
// NOTE: Layering violations!
// We decided to accept these violations (depending
// on other net/ submodules from net/base/), because otherwise NetworkDelegate
// would have to be broken up into too many smaller interfaces targeted to each
// submodule. Also, since the lower levels in net/ may callback into higher
// levels, we may encounter dangerous casting issues.
//
// NOTE: It is not okay to add any compile-time dependencies on symbols outside
// of net/base here, because we have a net_base library. Forward declarations
// are ok.
class HttpRequestHeaders;
class URLRequest;
class URLRequestJob;
class NetworkDelegate : public base::NonThreadSafe {
public:
virtual ~NetworkDelegate() {}
// Notification interface called by the network stack. Note that these
// functions mostly forward to the private virtuals. They also add some sanity
// checking on parameters. See the corresponding virtuals for explanations of
// the methods and their arguments.
int NotifyBeforeURLRequest(URLRequest* request,
CompletionCallback* callback,
GURL* new_url);
int NotifyBeforeSendHeaders(uint64 request_id,
CompletionCallback* callback,
HttpRequestHeaders* headers);
void NotifyResponseStarted(URLRequest* request);
void NotifyReadCompleted(URLRequest* request, int bytes_read);
void NotifyURLRequestDestroyed(URLRequest* request);
// Returns a URLRequestJob that will be used to handle the request if
// non-null.
// TODO(koz): Currently this is called inside registered ProtocolFactories,
// so that we can perform Delegate-dependent request handling from the static
// factories, but ultimately it should be called directly from
// URLRequestJobManager::CreateJob() as a general override mechanism.
URLRequestJob* MaybeCreateURLRequestJob(URLRequest* request);
private:
// This is the interface for subclasses of NetworkDelegate to implement. This
// member functions will be called by the respective public notification
// member function, which will perform basic sanity checking.
// Called before a request is sent. Allows the delegate to rewrite the URL
// being fetched by modifying |new_url|. The callback can be called at any
// time, but will have no effect if the request has already been cancelled or
// deleted. Returns a net status code, generally either OK to continue with
// the request or ERR_IO_PENDING if the result is not ready yet.
virtual int OnBeforeURLRequest(URLRequest* request,
CompletionCallback* callback,
GURL* new_url) = 0;
// Called right before the HTTP headers are sent. Allows the delegate to
// read/write |headers| before they get sent out. The callback can be called
// at any time, but will have no effect if the transaction handling this
// request has been cancelled. Returns a net status code.
virtual int OnBeforeSendHeaders(uint64 request_id,
CompletionCallback* callback,
HttpRequestHeaders* headers) = 0;
// This corresponds to URLRequestDelegate::OnResponseStarted.
virtual void OnResponseStarted(URLRequest* request) = 0;
// This corresponds to URLRequestDelegate::OnReadCompleted.
virtual void OnReadCompleted(URLRequest* request, int bytes_read) = 0;
// Called when an URLRequest is being destroyed. Note that the request is
// being deleted, so it's not safe to call any methods that may result in
// a virtual method call.
virtual void OnURLRequestDestroyed(URLRequest* request) = 0;
// Called before a request is sent and before a URLRequestJob is created to
// handle the request.
virtual URLRequestJob* OnMaybeCreateURLRequestJob(URLRequest* request) = 0;
};
} // namespace net
#endif // NET_BASE_NETWORK_DELEGATE_H_