net/proxy/proxy_script_fetcher.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // ProxyScriptFetcher is an async interface for fetching a proxy auto config
   6 // script. It is specific to fetching a PAC script; enforces timeout, max-size,
   7 // status code.
   8
   9 #ifndef NET_PROXY_PROXY_SCRIPT_FETCHER_H_
  10 #define NET_PROXY_PROXY_SCRIPT_FETCHER_H_
  11
  12 #include "base/strings/string16.h"
  13 #include "net/base/completion_callback.h"
  14 #include "net/base/net_export.h"
  15
  16 class GURL;
  17
  18 namespace net {
  19
  20 class URLRequestContext;
  21
  22 // Interface for downloading a PAC script. Implementations can enforce
  23 // timeouts, maximum size constraints, content encoding, etc..
  24 class NET_EXPORT_PRIVATE ProxyScriptFetcher {
  25  public:
  26   // Destruction should cancel any outstanding requests.
  27   virtual ~ProxyScriptFetcher() {}
  28
  29   // Downloads the given PAC URL, and invokes |callback| on completion.
  30   // Returns OK on success, otherwise the error code. If the return code is
  31   // ERR_IO_PENDING, then the request completes asynchronously, and |callback|
  32   // will be invoked later with the final error code.
  33   // After synchronous or asynchronous completion with a result code of OK,
  34   // |*utf16_text| is filled with the response. On failure, the result text is
  35   // an empty string, and the result code is a network error. Some special
  36   // network errors that may occur are:
  37   //
  38   //    ERR_TIMED_OUT         -- the fetch took too long to complete.
  39   //    ERR_FILE_TOO_BIG      -- the response's body was too large.
  40   //    ERR_PAC_STATUS_NOT_OK -- non-200 HTTP status code.
  41   //    ERR_NOT_IMPLEMENTED   -- the response required authentication.
  42   //
  43   // If the request is cancelled (either using the "Cancel()" method or by
  44   // deleting |this|), then no callback is invoked.
  45   //
  46   // Only one fetch is allowed to be outstanding at a time.
  47   virtual int Fetch(const GURL& url, base::string16* utf16_text,
  48                     const net::CompletionCallback& callback) = 0;
  49
  50   // Aborts the in-progress fetch (if any).
  51   virtual void Cancel() = 0;
  52
  53   // Returns the request context that this fetcher uses to issue downloads,
  54   // or NULL.
  55   virtual URLRequestContext* GetRequestContext() const = 0;
  56 };
  57
  58 }  // namespace net
  59
  60 #endif  // NET_PROXY_PROXY_SCRIPT_FETCHER_H_