// 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_H_
#define NET_PROXY_DHCP_SCRIPT_FETCHER_H_
#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/strings/string16.h"
#include "net/base/completion_callback.h"
#include "net/base/net_export.h"
#include "net/proxy/proxy_script_fetcher.h"
#include "url/gurl.h"
namespace net {
// Interface for classes that can fetch a proxy script as configured via DHCP.
//
// The Fetch method on this interface tries to retrieve the most appropriate
// PAC script configured via DHCP.
//
// Normally there are zero or one DHCP scripts configured, but in the
// presence of multiple adapters with DHCP enabled, the fetcher resolves
// which PAC script to use if one or more are available.
class NET_EXPORT_PRIVATE DhcpProxyScriptFetcher {
public:
// Destruction should cancel any outstanding requests.
virtual ~DhcpProxyScriptFetcher();
// Attempts to retrieve the most appropriate PAC script configured via DHCP,
// and invokes |callback| on completion.
//
// Returns OK on success, otherwise the error code. If the return code is
// ERR_IO_PENDING, then the request completes asynchronously, and |callback|
// will be invoked later with the final error code.
//
// After synchronous or asynchronous completion with a result code of OK,
// |*utf16_text| is filled with the response. On failure, the result text is
// an empty string, and the result code is a network error. Some special
// network errors that may occur are:
//
// ERR_PAC_NOT_IN_DHCP -- no script configured in DHCP.
//
// The following all indicate there was one or more script configured
// in DHCP but all failed to download, and the error for the most
// preferred adapter that had a script configured was what the error
// code says:
//
// ERR_TIMED_OUT -- fetch took too long to complete.
// ERR_FILE_TOO_BIG -- response body was too large.
// ERR_PAC_STATUS_NOT_OK -- script failed to download.
// ERR_NOT_IMPLEMENTED -- script required authentication.
//
// If the request is cancelled (either using the "Cancel()" method or by
// deleting |this|), then no callback is invoked.
//
// Only one fetch is allowed to be outstanding at a time.
virtual int Fetch(base::string16* utf16_text,
const CompletionCallback& callback) = 0;
// Aborts the in-progress fetch (if any).
virtual void Cancel() = 0;
// After successful completion of |Fetch()|, this will return the URL
// retrieved from DHCP. It is reset if/when |Fetch()| is called again.
virtual const GURL& GetPacURL() const = 0;
// Intended for unit tests only, so they can test that factories return
// the right types under given circumstances.
virtual std::string GetFetcherName() const;
protected:
DhcpProxyScriptFetcher();
private:
DISALLOW_COPY_AND_ASSIGN(DhcpProxyScriptFetcher);
};
// A do-nothing retriever, always returns synchronously with
// ERR_NOT_IMPLEMENTED result and empty text.
class NET_EXPORT_PRIVATE DoNothingDhcpProxyScriptFetcher
: public DhcpProxyScriptFetcher {
public:
DoNothingDhcpProxyScriptFetcher();
virtual ~DoNothingDhcpProxyScriptFetcher();
virtual int Fetch(base::string16* utf16_text,
const CompletionCallback& callback) OVERRIDE;
virtual void Cancel() OVERRIDE;
virtual const GURL& GetPacURL() const OVERRIDE;
private:
GURL gurl_;
DISALLOW_COPY_AND_ASSIGN(DoNothingDhcpProxyScriptFetcher);
};
} // namespace net
#endif // NET_PROXY_DHCP_SCRIPT_FETCHER_H_