net/base/upload_disk_cache_entry_element_reader.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 NET_BASE_UPLOAD_DISK_CACHE_ENTRY_ELEMENT_READER_H_
   6 #define NET_BASE_UPLOAD_DISK_CACHE_ENTRY_ELEMENT_READER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "net/base/completion_callback.h"
  12 #include "net/base/net_export.h"
  13 #include "net/base/upload_element_reader.h"
  14
  15 namespace disk_cache {
  16 class Entry;
  17 }
  18
  19 namespace net {
  20
  21 // An UploadElementReader implementation for disk_cache::Entry objects. The
  22 // caller keeps ownership of |disk_cache_entry|, and is responsible for ensuring
  23 // it outlives the UploadDiskCacheEntryElementReader.
  24 class NET_EXPORT UploadDiskCacheEntryElementReader
  25     : public UploadElementReader {
  26  public:
  27   // Construct a new UploadDiskCacheEntryElementReader which reads from the disk
  28   // cache entry |disk_cache_entry| with stream index |disk_cache_stream_index|.
  29   // The new upload reader object will read |range_length| bytes, starting from
  30   // |range_offset|. To read an whole cache entry give a 0 as |range_offset| and
  31   // provide the length of the entry's stream as |range_length|.
  32   UploadDiskCacheEntryElementReader(disk_cache::Entry* disk_cache_entry,
  33                                     int disk_cache_stream_index,
  34                                     int range_offset,
  35                                     int range_length);
  36   ~UploadDiskCacheEntryElementReader() override;
  37
  38   int range_offset_for_tests() const { return range_begin_offset_; }
  39   int range_length_for_tests() const {
  40     return range_end_offset_ - range_begin_offset_;
  41   }
  42
  43   // UploadElementReader overrides:
  44   const UploadDiskCacheEntryElementReader* AsDiskCacheEntryReaderForTests()
  45       const override;
  46   int Init(const CompletionCallback& callback) override;
  47   uint64_t GetContentLength() const override;
  48   uint64_t BytesRemaining() const override;
  49   bool IsInMemory() const override;
  50   int Read(IOBuffer* buf,
  51            int buf_length,
  52            const CompletionCallback& callback) override;
  53
  54  private:
  55   void OnReadCompleted(const CompletionCallback& callback, int result);
  56
  57   disk_cache::Entry* const disk_cache_entry_;
  58   const int disk_cache_stream_index_;
  59
  60   const int range_begin_offset_;
  61   const int range_end_offset_;
  62
  63   int current_read_offset_;
  64
  65   base::WeakPtrFactory<UploadDiskCacheEntryElementReader> weak_factory_;
  66
  67   DISALLOW_COPY_AND_ASSIGN(UploadDiskCacheEntryElementReader);
  68 };
  69
  70 }  // namespace net
  71
  72 #endif  // NET_BASE_UPLOAD_DISK_CACHE_ENTRY_ELEMENT_READER_H_