chrome/browser/net/file_downloader.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_NET_FILE_DOWNLOADER_H_
   6 #define CHROME_BROWSER_NET_FILE_DOWNLOADER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "net/url_request/url_fetcher_delegate.h"
  12
  13 namespace base {
  14 class FilePath;
  15 }  // namespace base
  16
  17 namespace net {
  18 class URLFetcher;
  19 class URLRequestContextGetter;
  20 }  // namespace net
  21
  22 class GURL;
  23
  24 // Helper class to download a file from a given URL and store it in a local
  25 // file. If the local file already exists, reports success without downloading
  26 // anything.
  27 // TODO(treib): Add a "bool overwrite" param?
  28 class FileDownloader : public net::URLFetcherDelegate {
  29  public:
  30   typedef base::Callback<void(bool /* success */)> DownloadFinishedCallback;
  31
  32   // Directly starts the download (if necessary) and runs |callback| when done.
  33   // If the instance is destroyed before it is finished, |callback| is not run.
  34   FileDownloader(const GURL& url,
  35                  const base::FilePath& path,
  36                  net::URLRequestContextGetter* request_context,
  37                  const DownloadFinishedCallback& callback);
  38   ~FileDownloader() override;
  39
  40  private:
  41   // net::URLFetcherDelegate implementation.
  42   void OnURLFetchComplete(const net::URLFetcher* source) override;
  43
  44   void OnFileExistsCheckDone(bool exists);
  45
  46   DownloadFinishedCallback callback_;
  47
  48   scoped_ptr<net::URLFetcher> fetcher_;
  49
  50   base::WeakPtrFactory<FileDownloader> weak_ptr_factory_;
  51
  52   DISALLOW_COPY_AND_ASSIGN(FileDownloader);
  53 };
  54
  55 #endif  // CHROME_BROWSER_NET_FILE_DOWNLOADER_H_