net/disk_cache/simple/simple_entry_format_history.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 NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_FORMAT_HISTORY_H_
   6 #define NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_FORMAT_HISTORY_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/port.h"
  10 #include "net/base/net_export.h"
  11
  12 namespace disk_cache {
  13
  14 namespace simplecache_v5 {
  15
  16 const uint64 kSimpleInitialMagicNumber = GG_UINT64_C(0xfcfb6d1ba7725c30);
  17 const uint64 kSimpleFinalMagicNumber = GG_UINT64_C(0xf4fa6f45970d41d8);
  18
  19 // A file containing stream 0 and stream 1 in the Simple cache consists of:
  20 //   - a SimpleFileHeader.
  21 //   - the key.
  22 //   - the data from stream 1.
  23 //   - a SimpleFileEOF record for stream 1.
  24 //   - the data from stream 0.
  25 //   - a SimpleFileEOF record for stream 0.
  26
  27 // A file containing stream 2 in the Simple cache consists of:
  28 //   - a SimpleFileHeader.
  29 //   - the key.
  30 //   - the data.
  31 //   - at the end, a SimpleFileEOF record.
  32 static const int kSimpleEntryFileCount = 2;
  33 static const int kSimpleEntryStreamCount = 3;
  34
  35 struct NET_EXPORT_PRIVATE SimpleFileHeader {
  36   SimpleFileHeader();
  37
  38   uint64 initial_magic_number;
  39   uint32 version;
  40   uint32 key_length;
  41   uint32 key_hash;
  42 };
  43
  44 struct NET_EXPORT_PRIVATE SimpleFileEOF {
  45   enum Flags {
  46     FLAG_HAS_CRC32 = (1U << 0),
  47   };
  48
  49   SimpleFileEOF();
  50
  51   uint64 final_magic_number;
  52   uint32 flags;
  53   uint32 data_crc32;
  54   // |stream_size| is only used in the EOF record for stream 0.
  55   uint32 stream_size;
  56 };
  57
  58 }  // namespace simplecache_v5
  59
  60 }  // namespace disk_cache
  61
  62 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_ENTRY_FORMAT_HISTORY_H_