Provide mutable members of UrlRequestContext via pure-virtual interface

net/url_request/url_request_context.h

 // Copyright (c) 2012 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.
 
 // This class represents contextual information (cookies, cache, etc.)
 // that's useful when processing resource requests.
 // The class is reference-counted so that it can be cleaned up after any
 // requests that are using it have been completed.
 
 #ifndef NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_
@@ skipping 22 matching lines @@
 class HostResolver;
 class HttpAuthHandlerFactory;
 class HttpTransactionFactory;
 class NetworkDelegate;
 class ServerBoundCertService;
 class ProxyService;
 class URLRequest;
 class URLRequestJobFactory;
 class URLRequestThrottlerManager;
 
+// A pure-virtual interface that provides the HTTP Accept-Language,
+// Accept-Charset and User-Agent header values.  An instance of an
+// implementation of this interface can be used by calling
+// |URLRequestContext::set_http_user_agent_settings()|.
+class NET_EXPORT HttpUserAgentSettings {

[erikwright (departed), 2012/09/21 15:06:33]

Move to http_user_agent_settings.h

+ public:
+  // Gets the value of 'Accept-Language' header field.
+  virtual const std::string& GetAcceptLanguage() = 0;
+  // Gets the value of 'Accept-Charset' header field.
+  virtual const std::string& GetAcceptCharset() = 0;
+  // Gets the UA string to use for the given URL.  Pass an invalid URL (such as

[erikwright (departed), 2012/09/21 15:06:33]

"Pass an invalid URL (such as GURL())" -> Pass an empty URL...

+  // GURL()) to get the default UA string.
+  virtual const std::string& GetUserAgent(const GURL& url) = 0;
+
+  virtual ~HttpUserAgentSettings() {}
+
+ protected:
+  HttpUserAgentSettings() {}

[erikwright (departed), 2012/09/21 15:06:33]

This can be public (no-one can call it because of the pure-virtual methods).

+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HttpUserAgentSettings);

[erikwright (departed), 2012/09/21 15:06:33]

This can be omitted on pure-virtual classes because they can't be constructed
anyways.

+};
+
+// A partial implementation of |HttpUserAgentSettings| that always provides
+// the same constant values for the HTTP Accept-Language and Accept-Charset
+// headers.  Implementors can inherit from this class and implement
+// |GetUserAgent()|.
+class NET_EXPORT ConstHttpAcceptLanguageAndCharset

[erikwright (departed), 2012/09/21 15:06:33]

move to separate file.

+  : public HttpUserAgentSettings {
+ public:
+  virtual const std::string& GetAcceptLanguage() OVERRIDE;
+  virtual const std::string& GetAcceptCharset() OVERRIDE;
+
+ protected:
+  ConstHttpAcceptLanguageAndCharset(const std::string& accept_language,
+                                    const std::string& accept_charset);
+  virtual ~ConstHttpAcceptLanguageAndCharset() {}
+
+ private:
+  const std::string accept_language_;
+  const std::string accept_charset_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConstHttpAcceptLanguageAndCharset);
+};
+
+// An implementation of |HttpUserAgentSettings| that always provides the
+// same constant values for the HTTP Accept-Language, Accept-Charset, and
+// User-Agent headers.
+class NET_EXPORT ConstHttpUserAgentSettings

[erikwright (departed), 2012/09/21 15:06:33]

move to separate file.

+  : public ConstHttpAcceptLanguageAndCharset {
+ public:
+  ConstHttpUserAgentSettings(const std::string& accept_language,
+                             const std::string& accept_charset,
+                             const std::string& user_agent);
+  virtual ~ConstHttpUserAgentSettings() {}
+
+  virtual const std::string& GetUserAgent(const GURL& url) OVERRIDE;
+
+ private:
+  const std::string user_agent_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConstHttpUserAgentSettings);
+};
+
+
 // Subclass to provide application-specific context for URLRequest
 // instances. Note that URLRequestContext typically does not provide storage for
 // these member variables, since they may be shared. For the ones that aren't
 // shared, URLRequestContextStorage can be helpful in defining their storage.
 class NET_EXPORT URLRequestContext
     : NON_EXPORTED_BASE(public base::NonThreadSafe) {
  public:
   URLRequestContext();
   virtual ~URLRequestContext();
 
@@ skipping 113 matching lines @@
   // Gets the FTP authentication cache for this context.
   FtpAuthCache* ftp_auth_cache() const {
 #if !defined(DISABLE_FTP_SUPPORT)
     return ftp_auth_cache_.get();
 #else
     return NULL;
 #endif
   }
 
   // Gets the value of 'Accept-Charset' header field.
-  const std::string& accept_charset() const { return accept_charset_; }
-  void set_accept_charset(const std::string& accept_charset) {
-    accept_charset_ = accept_charset;
-  }
+  const std::string& accept_charset() const;

[erikwright (departed), 2012/09/21 15:06:33]

Group these together with a single "Legacy accessors that delegate to ..."
comment.
Add a TODO(pauljensen): Remove after all clients are updated to directly access
...

 
   // Gets the value of 'Accept-Language' header field.
-  const std::string& accept_language() const { return accept_language_; }
-  void set_accept_language(const std::string& accept_language) {
-    accept_language_ = accept_language;
-  }
+  const std::string& accept_language() const;
 
   // Gets the UA string to use for the given URL.  Pass an invalid URL (such as
-  // GURL()) to get the default UA string.  Subclasses should override this
-  // method to provide a UA string.
-  virtual const std::string& GetUserAgent(const GURL& url) const;
+  // GURL()) to get the default UA string.
+  const std::string& GetUserAgent(const GURL& url) const;
 
   // In general, referrer_charset is not known when URLRequestContext is
   // constructed. So, we need a setter.
   const std::string& referrer_charset() const { return referrer_charset_; }
   void set_referrer_charset(const std::string& charset) {
     referrer_charset_ = charset;
   }
 
   const URLRequestJobFactory* job_factory() const { return job_factory_; }
   void set_job_factory(const URLRequestJobFactory* job_factory) {
     job_factory_ = job_factory;
   }
 
   // May be NULL.
   URLRequestThrottlerManager* throttler_manager() const {
     return throttler_manager_;
   }
   void set_throttler_manager(URLRequestThrottlerManager* throttler_manager) {
     throttler_manager_ = throttler_manager;
   }
 
   // Gets the URLRequest objects that hold a reference to this
   // URLRequestContext.
   std::set<const URLRequest*>* url_requests() const {
     return url_requests_.get();
   }
 
   void AssertNoURLRequests() const;
 
+  // Set the underlying |HttpUserAgentSettings| implementation that provides
+  // the HTTP Accept-Language, Accept-Charset and User-Agent header values that

[erikwright (departed), 2012/09/21 15:06:33]

Clients should actually access HttpUserAgentSettings directly very soon.

So just remove the bits about accept_language() etc.

+  // are returned by |accept_language|, |accept_charset|, and |GetUserAgent|.
+  // Note: This implementation is not owned by |URLRequestContext|, so it is

[erikwright (departed), 2012/09/21 15:06:33]

The "Note" is not required since it's the same as all other members. If we
weren't removing URLRequestContext ASAP I'd double check that the class comments
say as much, but right now I'm indifferent.

+  // the responsibility of the caller of |set_http_user_agent_settings| to
+  // ensure the implementation outlives the use of this |URLRequestContext|.
+  void set_http_user_agent_settings(
+    HttpUserAgentSettings* http_user_agent_settings) {
+      http_user_agent_settings_ = http_user_agent_settings;
+  }
+
  private:
   // ---------------------------------------------------------------------------
   // Important: When adding any new members below, consider whether they need to
   // be added to CopyFrom.
   // ---------------------------------------------------------------------------
 
   // Ownership for these members are not defined here. Clients should either
   // provide storage elsewhere or have a subclass take ownership.
   NetLog* net_log_;
   HostResolver* host_resolver_;
   CertVerifier* cert_verifier_;
   ServerBoundCertService* server_bound_cert_service_;
   FraudulentCertificateReporter* fraudulent_certificate_reporter_;
   HttpAuthHandlerFactory* http_auth_handler_factory_;
   ProxyService* proxy_service_;
   scoped_refptr<SSLConfigService> ssl_config_service_;
   NetworkDelegate* network_delegate_;
   HttpServerProperties* http_server_properties_;
   scoped_refptr<CookieStore> cookie_store_;
   TransportSecurityState* transport_security_state_;
 #if !defined(DISABLE_FTP_SUPPORT)
   scoped_ptr<FtpAuthCache> ftp_auth_cache_;
 #endif
-  std::string accept_language_;
-  std::string accept_charset_;
   // The charset of the referrer where this request comes from. It's not
   // used in communication with a server but is used to construct a suggested
   // filename for file download.
   std::string referrer_charset_;
   HttpTransactionFactory* http_transaction_factory_;
   FtpTransactionFactory* ftp_transaction_factory_;
   const URLRequestJobFactory* job_factory_;
   URLRequestThrottlerManager* throttler_manager_;
+  HttpUserAgentSettings* http_user_agent_settings_;
 
   // ---------------------------------------------------------------------------
   // Important: When adding any new members below, consider whether they need to
   // be added to CopyFrom.
   // ---------------------------------------------------------------------------
 
   scoped_ptr<std::set<const URLRequest*> > url_requests_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestContext);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_