Add unit-tests for SingleRequestHostResolver.

net/base/single_request_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_HOST_RESOLVER_H_
-#define NET_BASE_HOST_RESOLVER_H_
+#ifndef NET_BASE_SINGLE_REQUEST_HOST_RESOLVER_H_
+#define NET_BASE_SINGLE_REQUEST_HOST_RESOLVER_H_
 #pragma once
 
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "googleurl/src/gurl.h"
-#include "net/base/address_family.h"
-#include "net/base/completion_callback.h"
-#include "net/base/host_port_pair.h"
-#include "net/base/net_api.h"
-#include "net/base/request_priority.h"
+#include "net/base/host_resolver.h"
 
 namespace net {
 
-class AddressList;
-class BoundNetLog;
-class HostResolverImpl;
-class HostResolverProc;
-class NetLog;
-
-// This class represents the task of resolving hostnames (or IP address
-// literal) to an AddressList object.
-//
-// HostResolver can handle multiple requests at a time, so when cancelling a
-// request the RequestHandle that was returned by Resolve() needs to be
-// given.  A simpler alternative for consumers that only have 1 outstanding
-// request at a time is to create a SingleRequestHostResolver wrapper around
-// HostResolver (which will automatically cancel the single request when it
-// goes out of scope).
-class NET_API HostResolver {
- public:
-  // The parameters for doing a Resolve(). A hostname and port are required,
-  // the rest are optional (and have reasonable defaults).
-  class NET_API RequestInfo {
-   public:
-    explicit RequestInfo(const HostPortPair& host_port_pair);
-
-    const HostPortPair& host_port_pair() const { return host_port_pair_; }
-    void set_host_port_pair(const HostPortPair& host_port_pair) {
-      host_port_pair_ = host_port_pair;
-    }
-
-    int port() const { return host_port_pair_.port(); }
-    const std::string& hostname() const { return host_port_pair_.host(); }
-
-    AddressFamily address_family() const { return address_family_; }
-    void set_address_family(AddressFamily address_family) {
-      address_family_ = address_family;
-    }
-
-    HostResolverFlags host_resolver_flags() const {
-      return host_resolver_flags_;
-    }
-    void set_host_resolver_flags(HostResolverFlags host_resolver_flags) {
-      host_resolver_flags_ = host_resolver_flags;
-    }
-
-    bool allow_cached_response() const { return allow_cached_response_; }
-    void set_allow_cached_response(bool b) { allow_cached_response_ = b; }
-
-    bool only_use_cached_response() const { return only_use_cached_response_; }
-    void set_only_use_cached_response(bool b) { only_use_cached_response_ = b; }
-
-    bool is_speculative() const { return is_speculative_; }
-    void set_is_speculative(bool b) { is_speculative_ = b; }
-
-    RequestPriority priority() const { return priority_; }
-    void set_priority(RequestPriority priority) { priority_ = priority; }
-
-    const GURL& referrer() const { return referrer_; }
-    void set_referrer(const GURL& referrer) { referrer_ = referrer; }
-
-   private:
-    // The hostname to resolve, and the port to use in resulting sockaddrs.
-    HostPortPair host_port_pair_;
-
-    // The address family to restrict results to.
-    AddressFamily address_family_;
-
-    // Flags to use when resolving this request.
-    HostResolverFlags host_resolver_flags_;
-
-    // Whether it is ok to return a result from the host cache.
-    bool allow_cached_response_;
-
-    // Whether the response will only use the cache.
-    bool only_use_cached_response_;
-
-    // Whether this request was started by the DNS prefetcher.
-    bool is_speculative_;
-
-    // The priority for the request.
-    RequestPriority priority_;
-
-    // Optional data for consumption by observers. This is the URL of the
-    // page that lead us to the navigation, for DNS prefetcher's benefit.
-    GURL referrer_;
-  };
-
-  // Interface for observing the requests that flow through a HostResolver.
-  class Observer {
-   public:
-    virtual ~Observer() {}
-
-    // Called at the start of HostResolver::Resolve(). |id| is a unique number
-    // given to the request, so it can be matched up with a corresponding call
-    // to OnFinishResolutionWithStatus() or OnCancelResolution().
-    virtual void OnStartResolution(int id, const RequestInfo& info) = 0;
-
-    // Called on completion of request |id|. Note that if the request was
-    // cancelled, OnCancelResolution() will be called instead.
-    virtual void OnFinishResolutionWithStatus(int id, bool was_resolved,
-                                              const RequestInfo& info) = 0;
-
-    // Called when request |id| has been cancelled. A request is "cancelled"
-    // if either the HostResolver is destroyed while a resolution is in
-    // progress, or HostResolver::CancelRequest() is called.
-    virtual void OnCancelResolution(int id, const RequestInfo& info) = 0;
-  };
-
-  // Opaque type used to cancel a request.
-  typedef void* RequestHandle;
-
-  // This value can be passed into CreateSystemHostResolver as the
-  // |max_concurrent_resolves| parameter. It will select a default level of
-  // concurrency.
-  static const size_t kDefaultParallelism = 0;
-
-  // This value can be passed into CreateSystemHostResolver as the
-  // |max_retry_attempts| parameter. This is the maximum number of times we
-  // will retry for host resolution.
-  static const size_t kDefaultRetryAttempts = -1;
-
-  // If any completion callbacks are pending when the resolver is destroyed,
-  // the host resolutions are cancelled, and the completion callbacks will not
-  // be called.
-  virtual ~HostResolver();
-
-  // Resolves the given hostname (or IP address literal), filling out the
-  // |addresses| object upon success.  The |info.port| parameter will be set as
-  // the sin(6)_port field of the sockaddr_in{6} struct.  Returns OK if
-  // successful or an error code upon failure.
-  //
-  // When callback is null, the operation completes synchronously.
-  //
-  // When callback is non-null, the operation may be performed asynchronously.
-  // If the operation cannnot be completed synchronously, ERR_IO_PENDING will
-  // be returned and the real result code will be passed to the completion
-  // callback.  Otherwise the result code is returned immediately from this
-  // call.
-  // If |out_req| is non-NULL, then |*out_req| will be filled with a handle to
-  // the async request. This handle is not valid after the request has
-  // completed.
-  //
-  // Profiling information for the request is saved to |net_log| if non-NULL.
-  virtual int Resolve(const RequestInfo& info,
-                      AddressList* addresses,
-                      CompletionCallback* callback,
-                      RequestHandle* out_req,
-                      const BoundNetLog& net_log) = 0;
-
-  // Cancels the specified request. |req| is the handle returned by Resolve().
-  // After a request is cancelled, its completion callback will not be called.
-  virtual void CancelRequest(RequestHandle req) = 0;
-
-  // Adds an observer to this resolver. The observer will be notified of the
-  // start and completion of all requests (excluding cancellation). |observer|
-  // must remain valid for the duration of this HostResolver's lifetime.
-  virtual void AddObserver(Observer* observer) = 0;
-
-  // Unregisters an observer previously added by AddObserver().
-  virtual void RemoveObserver(Observer* observer) = 0;
-
-  // Sets the default AddressFamily to use when requests have left it
-  // unspecified. For example, this could be used to restrict resolution
-  // results to AF_INET by passing in ADDRESS_FAMILY_IPV4, or to
-  // AF_INET6 by passing in ADDRESS_FAMILY_IPV6.
-  virtual void SetDefaultAddressFamily(AddressFamily address_family) {}
-  virtual AddressFamily GetDefaultAddressFamily() const;
-
-  // Returns |this| cast to a HostResolverImpl*, or NULL if the subclass
-  // is not compatible with HostResolverImpl. Used primarily to expose
-  // additional functionality on the about:net-internals page.
-  virtual HostResolverImpl* GetAsHostResolverImpl();
-
-  // Does additional cleanup prior to destruction.
-  virtual void Shutdown() {}
-
- protected:
-  HostResolver();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(HostResolver);
-};
-
 // This class represents the task of resolving a hostname (or IP address
 // literal) to an AddressList object.  It wraps HostResolver to resolve only a
 // single hostname at a time and cancels this request when going out of scope.
-class SingleRequestHostResolver {
+class NET_API SingleRequestHostResolver {
  public:
   // |resolver| must remain valid for the lifetime of |this|.
   explicit SingleRequestHostResolver(HostResolver* resolver);
 
   // If a completion callback is pending when the resolver is destroyed, the
   // host resolution is cancelled, and the completion callback will not be
   // called.
   ~SingleRequestHostResolver();
 
   // Resolves the given hostname (or IP address literal), filling out the
@@ skipping 18 matching lines @@
   // The current request (if any).
   HostResolver::RequestHandle cur_request_;
   CompletionCallback* cur_request_callback_;
 
   // Completion callback for when request to |resolver_| completes.
   CompletionCallbackImpl<SingleRequestHostResolver> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleRequestHostResolver);
 };
 
-// Creates a HostResolver implementation that queries the underlying system.
-// (Except if a unit-test has changed the global HostResolverProc using
-// ScopedHostResolverProc to intercept requests to the system).
-// |max_concurrent_resolves| is how many resolve requests will be allowed to
-// run in parallel. Pass HostResolver::kDefaultParallelism to choose a
-// default value.
-// |max_retry_attempts| is the maximum number of times we will retry for host
-// resolution. Pass HostResolver::kDefaultRetryAttempts to choose a default
-// value.
-NET_API HostResolver* CreateSystemHostResolver(size_t max_concurrent_resolves,
-                                               size_t max_retry_attempts,
-                                               NetLog* net_log);
-
 }  // namespace net
 
-#endif  // NET_BASE_HOST_RESOLVER_H_
+#endif  // NET_BASE_SINGLE_REQUEST_HOST_RESOLVER_H_