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      1 // Copyright (c) 2010 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 #ifndef NET_PROXY_INIT_PROXY_RESOLVER_H_
      6 #define NET_PROXY_INIT_PROXY_RESOLVER_H_
      7 #pragma once
      8 
      9 #include <vector>
     10 
     11 #include "base/string16.h"
     12 #include "base/time.h"
     13 #include "base/timer.h"
     14 #include "googleurl/src/gurl.h"
     15 #include "net/base/completion_callback.h"
     16 #include "net/base/net_log.h"
     17 
     18 namespace net {
     19 
     20 class ProxyConfig;
     21 class ProxyResolver;
     22 class ProxyScriptFetcher;
     23 
     24 // InitProxyResolver is a helper class used by ProxyService to
     25 // initialize a ProxyResolver with the PAC script data specified
     26 // by a particular ProxyConfig.
     27 //
     28 // This involves trying to use PAC scripts in this order:
     29 //
     30 //   (1) WPAD (DNS) if auto-detect is on.
     31 //   (2) Custom PAC script if a URL was given.
     32 //
     33 // If no PAC script was successfully downloaded + parsed, then it fails with
     34 // a network error. Otherwise the proxy resolver is left initialized with
     35 // the PAC script.
     36 //
     37 // Deleting InitProxyResolver while Init() is in progress, will
     38 // cancel the request.
     39 //
     40 class InitProxyResolver {
     41  public:
     42   // |resolver|, |proxy_script_fetcher| and |net_log| must remain valid for
     43   // the lifespan of InitProxyResolver.
     44   InitProxyResolver(ProxyResolver* resolver,
     45                     ProxyScriptFetcher* proxy_script_fetcher,
     46                     NetLog* net_log);
     47 
     48   // Aborts any in-progress request.
     49   ~InitProxyResolver();
     50 
     51   // Applies the PAC settings of |config| to |resolver_|.
     52   // If |wait_delay| is positive, the initialization will pause for this
     53   // amount of time before getting started.
     54   // If |effective_config| is non-NULL, then on successful initialization of
     55   // |resolver_| the "effective" proxy settings we ended up using will be
     56   // written out to |*effective_config|. Note that this may differ from
     57   // |config| since we will have stripped any manual settings, and decided
     58   // whether to use auto-detect or the custom PAC URL. Finally, if auto-detect
     59   // was used we may now have resolved that to a specific script URL.
     60   int Init(const ProxyConfig& config,
     61            const base::TimeDelta wait_delay,
     62            ProxyConfig* effective_config,
     63            CompletionCallback* callback);
     64 
     65  private:
     66   struct PacURL {
     67     PacURL(bool auto_detect, const GURL& url)
     68         : auto_detect(auto_detect), url(url) {}
     69     bool auto_detect;
     70     GURL url;
     71   };
     72 
     73   typedef std::vector<PacURL> UrlList;
     74 
     75   enum State {
     76     STATE_NONE,
     77     STATE_WAIT,
     78     STATE_WAIT_COMPLETE,
     79     STATE_FETCH_PAC_SCRIPT,
     80     STATE_FETCH_PAC_SCRIPT_COMPLETE,
     81     STATE_SET_PAC_SCRIPT,
     82     STATE_SET_PAC_SCRIPT_COMPLETE,
     83   };
     84 
     85   // Returns ordered list of PAC urls to try for |config|.
     86   UrlList BuildPacUrlsFallbackList(const ProxyConfig& config) const;
     87 
     88   void OnIOCompletion(int result);
     89   int DoLoop(int result);
     90   void DoCallback(int result);
     91 
     92   int DoWait();
     93   int DoWaitComplete(int result);
     94 
     95   int DoFetchPacScript();
     96   int DoFetchPacScriptComplete(int result);
     97 
     98   int DoSetPacScript();
     99   int DoSetPacScriptComplete(int result);
    100 
    101   // Tries restarting using the next fallback PAC URL:
    102   // |pac_urls_[++current_pac_url_index]|.
    103   // Returns OK and rewinds the state machine when there
    104   // is something to try, otherwise returns |error|.
    105   int TryToFallbackPacUrl(int error);
    106 
    107   // Gets the initial state (we skip fetching when the
    108   // ProxyResolver doesn't |expect_pac_bytes()|.
    109   State GetStartState() const;
    110 
    111   // Returns the current PAC URL we are fetching/testing.
    112   const PacURL& current_pac_url() const;
    113 
    114   void OnWaitTimerFired();
    115   void DidCompleteInit();
    116   void Cancel();
    117 
    118   ProxyResolver* resolver_;
    119   ProxyScriptFetcher* proxy_script_fetcher_;
    120 
    121   CompletionCallbackImpl<InitProxyResolver> io_callback_;
    122   CompletionCallback* user_callback_;
    123 
    124   size_t current_pac_url_index_;
    125 
    126   // Filled when the PAC script fetch completes.
    127   string16 pac_script_;
    128 
    129   UrlList pac_urls_;
    130   State next_state_;
    131 
    132   BoundNetLog net_log_;
    133 
    134   base::TimeDelta wait_delay_;
    135   base::OneShotTimer<InitProxyResolver> wait_timer_;
    136 
    137   ProxyConfig* effective_config_;
    138 
    139   DISALLOW_COPY_AND_ASSIGN(InitProxyResolver);
    140 };
    141 
    142 }  // namespace net
    143 
    144 #endif  // NET_PROXY_INIT_PROXY_RESOLVER_H_
    145