AU: Beginnings of delta support

src/platform/update_engine/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 UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
-#define UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
+#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>
 #include <glib.h>
 #include "base/basictypes.h"
-#include "base/logging.h"
+#include "chromeos/obsolete_logging.h"
 #include "update_engine/http_fetcher.h"
 
 // This is a concrete implementation of HttpFetcher that uses libcurl to do the
 // http work.
 
 namespace chromeos_update_engine {
 
 class LibcurlHttpFetcher : public HttpFetcher {
  public:
   LibcurlHttpFetcher()
@@ skipping 23 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_ms(long ms) {
     idle_ms_ = ms;
   }
  private:
+  // 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);
 
   // These two methods are for glib main loop callbacks. They are called
   // when either a file descriptor is ready for work or when a timer
   // has fired. The static versions are shims for libcurl which has a C API.
   bool FDCallback(GIOChannel *source, GIOCondition condition);
   static gboolean StaticFDCallback(GIOChannel *source,
                                    GIOCondition condition,
                                    gpointer data) {
     return reinterpret_cast<LibcurlHttpFetcher*>(data)->FDCallback(source,
                                                                    condition);
@@ skipping 35 matching lines @@
   // 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
   // when it fires.
   GSource* timeout_source_;
 
   bool transfer_in_progress_;
 
+  // The transfer size. -1 if not known.
+  off_t transfer_size_;
+
+  // How many bytes have been downloaded and sent to the delegate.
+  off_t bytes_downloaded_;
+
+  // If we resumed an earlier transfer, data offset that we used for the
+  // new connection.  0 otherwise.
+  off_t resume_offset_;
+
   long idle_ms_;
   DISALLOW_COPY_AND_ASSIGN(LibcurlHttpFetcher);
 };
 
 }  // namespace chromeos_update_engine
 
-#endif  // UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__