// 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.
#ifndef NET_PROXY_DHCP_SCRIPT_FETCHER_FACTORY_H_
#define NET_PROXY_DHCP_SCRIPT_FETCHER_FACTORY_H_
#include "base/basictypes.h"
#include "base/memory/singleton.h"
#include "net/base/completion_callback.h"
#include "net/base/net_export.h"
namespace net {
class DhcpProxyScriptFetcher;
class URLRequestContext;
// Factory object for creating the appropriate concrete base class of
// DhcpProxyScriptFetcher for your operating system and settings.
//
// You might think we could just implement a DHCP client at the protocol
// level and have cross-platform support for retrieving PAC configuration
// from DHCP, but unfortunately the DHCP protocol assumes there is a single
// client per machine (specifically per network interface card), and there
// is an implicit state machine between the client and server, so adding a
// second client to the machine would not be advisable (see e.g. some
// discussion of what can happen at this URL:
// http://www.net.princeton.edu/multi-dhcp-one-interface-handling.html).
//
// Therefore, we have platform-specific implementations, and so we use
// this factory to select the right one.
class NET_EXPORT DhcpProxyScriptFetcherFactory {
public:
// Creates a new factory object with default settings.
DhcpProxyScriptFetcherFactory();
// Ownership is transferred to the caller. url_request_context must be valid
// and its lifetime must exceed that of the returned DhcpProxyScriptFetcher.
//
// Note that while a request is in progress, the fetcher may be holding a
// reference to |url_request_context|. Be careful not to create cycles
// between the fetcher and the context; you can break such cycles by calling
// Cancel().
DhcpProxyScriptFetcher* Create(URLRequestContext* url_request_context);
// Attempts to enable/disable the DHCP WPAD feature. Does nothing
// if |IsSupported()| returns false.
//
// The default is |enabled() == true|.
void set_enabled(bool enabled);
// Returns true if the DHCP WPAD feature is enabled. Always returns
// false if |IsSupported()| is false.
bool enabled() const;
// Returns true if the DHCP WPAD feature is supported on the current
// operating system.
static bool IsSupported();
private:
bool feature_enabled_;
DISALLOW_COPY_AND_ASSIGN(DhcpProxyScriptFetcherFactory);
};
} // namespace net
#endif // NET_PROXY_DHCP_SCRIPT_FETCHER_FACTORY_H_