Improve performance of proxy resolver by tracing DNS dependencies.

net/base/mock_host_resolver.h

 // Copyright (c) 2011 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_BASE_MOCK_HOST_RESOLVER_H_
 #define NET_BASE_MOCK_HOST_RESOLVER_H_
 
 #include <list>
 #include <map>
 
@@ skipping 76 matching lines @@
 
   // Resolves all pending requests. It is only valid to invoke this if
   // set_ondemand_mode was set before. The requests are resolved asynchronously,
   // after this call returns.
   void ResolveAllPending();
 
   // Returns true if there are pending requests that can be resolved by invoking
   // ResolveAllPending().
   bool has_pending_requests() const { return !requests_.empty(); }
 
+  // The number of times that Resolve() has been called.
+  size_t num_resolve() const {
+    return num_resolve_;
+  }
+
+  // The number of times that ResolveFromCache() has been called.
+  size_t num_resolve_from_cache() const {
+    return num_resolve_from_cache_;
+  }
+
  protected:
   explicit MockHostResolverBase(bool use_caching);
 
  private:
   struct Request;
   typedef std::map<size_t, Request*> RequestMap;
 
   // Resolve as IP or from |cache_| return cached error or
   // DNS_CACHE_MISS if failed.
   int ResolveFromIPLiteralOrCache(const RequestInfo& info,
                                   AddressList* addresses);
   // Resolve via |proc_|.
   int ResolveProc(size_t id, const RequestInfo& info, AddressList* addresses);
   // Resolve request stored in |requests_|. Pass rv to callback.
   void ResolveNow(size_t id);
 
   bool synchronous_mode_;
   bool ondemand_mode_;
   scoped_refptr<RuleBasedHostResolverProc> rules_;
   scoped_ptr<HostCache> cache_;
   RequestMap requests_;
   size_t next_request_id_;
 
+  size_t num_resolve_;
+  size_t num_resolve_from_cache_;
+
   DISALLOW_COPY_AND_ASSIGN(MockHostResolverBase);
 };
 
 class MockHostResolver : public MockHostResolverBase {
  public:
   MockHostResolver() : MockHostResolverBase(false /*use_caching*/) {}
   virtual ~MockHostResolver() {}
 };
 
 // Same as MockHostResolver, except internally it uses a host-cache.
@@ skipping 21 matching lines @@
                const std::string& replacement);
 
   // Same as AddRule(), but further restricts to |address_family|.
   void AddRuleForAddressFamily(const std::string& host_pattern,
                                AddressFamily address_family,
                                const std::string& replacement);
 
   // Same as AddRule(), but the replacement is expected to be an IPv4 or IPv6
   // literal. This can be used in place of AddRule() to bypass the system's
   // host resolver (the address list will be constructed manually).
-  // If |canonical-name| is non-empty, it is copied to the resulting AddressList
+  // If |canonical_name| is non-empty, it is copied to the resulting AddressList
   // but does not impact DNS resolution.
+  // |ip_literal| can be a single IP address like "192.168.1.1" or a comma
+  // separated list of IP addresses, like "::1,192:168.1.2".
   void AddIPLiteralRule(const std::string& host_pattern,
                         const std::string& ip_literal,
                         const std::string& canonical_name);
 
   void AddRuleWithLatency(const std::string& host_pattern,
                           const std::string& replacement,
                           int latency_ms);
 
   // Make sure that |host| will not be re-mapped or even processed by underlying
   // host resolver procedures. It can also be a pattern.
   void AllowDirectLookup(const std::string& host);
 
   // Simulate a lookup failure for |host| (it also can be a pattern).
   void AddSimulatedFailure(const std::string& host);
 
+  // Deletes all the rules that have been added.
+  void ClearRules();
+
   // HostResolverProc methods:
   virtual int Resolve(const std::string& host,
                       AddressFamily address_family,
                       HostResolverFlags host_resolver_flags,
                       AddressList* addrlist,
                       int* os_error) OVERRIDE;
 
  private:
   struct Rule;
   typedef std::list<Rule> RuleList;
@@ skipping 39 matching lines @@
   void Init(HostResolverProc* proc);
 
  private:
   scoped_refptr<HostResolverProc> current_proc_;
   scoped_refptr<HostResolverProc> previous_proc_;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_MOCK_HOST_RESOLVER_H_