AU: Don't use network on expensive connection types

libcurl_http_fetcher.h

 // Copyright (c) 2009 The Chromium OS 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
 
 #include <map>
 #include <string>
 #include <curl/curl.h>
@@ skipping 15 matching lines @@
       : curl_multi_handle_(NULL),
         curl_handle_(NULL),
         timeout_source_(NULL),
         transfer_in_progress_(false),
         transfer_size_(0),
         bytes_downloaded_(0),
         resume_offset_(0),
         retry_count_(0),
         retry_seconds_(60),
         idle_seconds_(1),
+        force_connection_type_(false),
+        forced_expensive_connection_(false),
         in_write_callback_(false),
         terminate_requested_(false) {}
 
   // Cleans up all internal state. Does not notify delegate
   ~LibcurlHttpFetcher();
 
   void SetOffset(off_t offset) { bytes_downloaded_ = offset; }
 
   // Begins the transfer if it hasn't already begun.
   virtual void BeginTransfer(const std::string& url);
@@ skipping 14 matching lines @@
   // primarily useful for testing.
   // From http://curl.haxx.se/libcurl/c/curl_multi_timeout.html:
   //     if libcurl returns a -1 timeout here, it just means that libcurl
   //     currently has no stored timeout value. You must not wait too long
   //     (more than a few seconds perhaps) before you call
   //     curl_multi_perform() again.
   void set_idle_seconds(int seconds) { idle_seconds_ = seconds; }
 
   // Sets the retry timeout. Useful for testing.
   void set_retry_seconds(int seconds) { retry_seconds_ = seconds; }
+  
+  void SetConnectionAsExpensive(bool is_expensive) {
+    force_connection_type_ = true;
+    forced_expensive_connection_ = is_expensive;
+  }
 
  private:
   // Asks libcurl for the http response code and stores it in the object.
   void GetHttpResponseCode();
 
   // Resumes a transfer where it left off. This will use the
   // HTTP Range: header to make a new connection from where the last
   // left off.
   virtual void ResumeTransfer(const std::string& url);
 
@@ skipping 35 matching lines @@
   static size_t StaticLibcurlWrite(void *ptr, size_t size,
                                    size_t nmemb, void *stream) {
     return reinterpret_cast<LibcurlHttpFetcher*>(stream)->
         LibcurlWrite(ptr, size, nmemb);
   }
 
   // Cleans up the following if they are non-null:
   // curl(m) handles, io_channels_, timeout_source_.
   void CleanUp();
 
+  // Returns whether or not the current network connection is considered
+  // expensive.
+  bool ConnectionIsExpensive() const;
+
   // Handles for the libcurl library
   CURLM *curl_multi_handle_;
   CURL *curl_handle_;
 
   // a list of all file descriptors that we're waiting on from the
   // glib main loop
   typedef std::map<int, std::pair<GIOChannel*, guint> > IOChannels;
   IOChannels io_channels_;
 
   // if non-NULL, a timer we're waiting on. glib main loop will call us back
@@ skipping 15 matching lines @@
   off_t resume_offset_;
 
   // Number of resumes performed.
   int retry_count_;
 
   // Seconds to wait before retrying a resume.
   int retry_seconds_;
 
   // Seconds to wait before asking libcurl to "perform".
   int idle_seconds_;
+  
+  // If true, assume the network is expensive or not, according to
+  // forced_expensive_connection_. (Useful for testing).
+  bool force_connection_type_;
+  bool forced_expensive_connection_;
 
   // If true, we are currently performing a write callback on the delegate.
   bool in_write_callback_;
   
   // We can't clean everything up while we're in a write callback, so
   // if we get a terminate request, queue it until we can handle it.
   bool terminate_requested_;
 
   DISALLOW_COPY_AND_ASSIGN(LibcurlHttpFetcher);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__