| // 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_PAC_FILE_FETCHER_FACTORY_H_ |
| #define NET_PROXY_DHCP_PAC_FILE_FETCHER_FACTORY_H_ |
| |
| #include <memory> |
| |
| #include "base/macros.h" |
| #include "base/memory/singleton.h" |
| #include "net/base/net_export.h" |
| #include "net/proxy_resolution/dhcp_pac_file_fetcher.h" |
| |
| namespace net { |
| |
| class URLRequestContext; |
| |
| // Factory object for creating the appropriate concrete base class of |
| // DhcpPacFileFetcher 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 DhcpPacFileFetcherFactory { |
| public: |
| DhcpPacFileFetcherFactory(); |
| |
| virtual ~DhcpPacFileFetcherFactory(); |
| |
| // url_request_context must be valid and its lifetime must exceed that of the |
| // returned DhcpPacFileFetcher. |
| // |
| // 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(). |
| virtual std::unique_ptr<DhcpPacFileFetcher> Create( |
| URLRequestContext* url_request_context); |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(DhcpPacFileFetcherFactory); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_PROXY_DHCP_PAC_FILE_FETCHER_FACTORY_H_ |