net/base/mapped_host_resolver.h

   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_BASE_MAPPED_HOST_RESOLVER_H_
   6 #define NET_BASE_MAPPED_HOST_RESOLVER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/ref_counted.h"
  12 #include "net/base/host_resolver.h"
  13
  14 namespace net {
  15
  16 // This class wraps an existing HostResolver instance, but modifies the
  17 // request before passing it off to |impl|. This is different from
  18 // MockHostResolver which does the remapping at the HostResolverProc
  19 // layer, so it is able to preserve the effectiveness of the cache.
  20 class MappedHostResolver : public HostResolver {
  21  public:
  22   // Creates a MappedHostResolver that forwards all of its requests through
  23   // |impl|.
  24   explicit MappedHostResolver(HostResolver* impl);
  25
  26   // HostResolver methods:
  27   virtual int Resolve(const RequestInfo& info,
  28                       AddressList* addresses,
  29                       CompletionCallback* callback,
  30                       RequestHandle* out_req,
  31                       LoadLog* load_log);
  32   virtual void CancelRequest(RequestHandle req);
  33   virtual void AddObserver(Observer* observer);
  34   virtual void RemoveObserver(Observer* observer);
  35   virtual HostResolverImpl* GetAsHostResolverImpl();
  36
  37   // Adds a rule to this mapper. The format of the rule can be one of:
  38   //
  39   //   "MAP" <hostname_pattern> <replacement_host> [":" <replacement_port>]
  40   //   "EXCLUDE" <hostname_pattern>
  41   //
  42   // The <replacement_host> can be either a hostname, or an IP address literal.
  43   //
  44   // Returns true if the rule was successfully parsed and added.
  45   bool AddRuleFromString(const std::string& rule_string);
  46
  47   // Takes a comma separated list of rules, and assigns them to this resolver.
  48   void SetRulesFromString(const std::string& rules_string);
  49
  50  private:
  51   struct MapRule {
  52     MapRule() : replacement_port(-1) {}
  53
  54     std::string hostname_pattern;
  55     std::string replacement_hostname;
  56     int replacement_port;
  57   };
  58
  59   struct ExclusionRule {
  60     std::string hostname_pattern;
  61   };
  62
  63   typedef std::vector<MapRule> MapRuleList;
  64   typedef std::vector<ExclusionRule> ExclusionRuleList;
  65
  66   virtual ~MappedHostResolver();
  67
  68   // Modifies |*info| based on the current rules. Returns true if the
  69   // RequestInfo was modified, false otherwise.
  70   bool RewriteRequest(RequestInfo* info) const;
  71
  72   scoped_refptr<HostResolver> impl_;
  73
  74   MapRuleList map_rules_;
  75   ExclusionRuleList exclusion_rules_;
  76 };
  77
  78 }  // namespace net
  79
  80 #endif  // NET_BASE_MAPPED_HOST_RESOLVER_H_