chrome/browser/extensions/blob_reader.h

   1 // Copyright 2013 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_EXTENSIONS_BLOB_READER_H_
   6 #define CHROME_BROWSER_EXTENSIONS_BLOB_READER_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "net/base/io_buffer.h"
  13 #include "net/url_request/url_fetcher_delegate.h"
  14 #include "net/url_request/url_request.h"
  15 #include "url/gurl.h"
  16
  17 class Profile;
  18 namespace net {
  19 class URLFetcher;
  20 }
  21
  22 // This class may only be used from the UI thread.
  23 class BlobReader : public net::URLFetcherDelegate {
  24  public:
  25   // |blob_data| contains the portion of the Blob requested. |blob_total_size|
  26   // is the total size of the Blob, and may be larger than |blob_data->size()|.
  27   // |blob_total_size| is -1 if it cannot be determined.
  28   typedef base::Callback<void(scoped_ptr<std::string> blob_data,
  29                               int64 blob_total_size)>
  30       BlobReadCallback;
  31
  32   BlobReader(Profile* profile,
  33              const std::string& blob_uuid,
  34              BlobReadCallback callback);
  35   ~BlobReader() override;
  36
  37   void SetByteRange(int64 offset, int64 length);
  38
  39   void Start();
  40
  41  private:
  42   // Overridden from net::URLFetcherDelegate.
  43   void OnURLFetchComplete(const net::URLFetcher* source) override;
  44
  45   BlobReadCallback callback_;
  46   scoped_ptr<net::URLFetcher> fetcher_;
  47
  48   DISALLOW_COPY_AND_ASSIGN(BlobReader);
  49 };
  50
  51 #endif  // CHROME_BROWSER_EXTENSIONS_BLOB_READER_H_