src/add-ons/kernel/file_systems/ext2/DataStream.h

   1 /*
   2  * Copyright 2001-2010, Haiku Inc. All rights reserved.
   3  * This file may be used under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Janito V. Ferreira Filho
   7  */
   8 #ifndef DATASTREAM_H
   9 #define DATASTREAM_H
  10
  11
  12 #include "ext2.h"
  13 #include "Transaction.h"
  14
  15
  16 class Volume;
  17
  18
  19 class DataStream
  20 {
  21 public:
  22                                         DataStream(Volume* volume, ext2_data_stream* stream,
  23                                                 off_t size);
  24                                         ~DataStream();
  25
  26         status_t                FindBlock(off_t offset, fsblock_t& block,
  27                                                 uint32 *_count = NULL);
  28         status_t                Enlarge(Transaction& transaction, off_t& numBlocks);
  29         status_t                Shrink(Transaction& transaction, off_t& numBlocks);
  30
  31 private:
  32         uint32                  _BlocksNeeded(off_t end);
  33
  34         status_t                _GetBlock(Transaction& transaction, uint32& block);
  35         status_t                _PrepareBlock(Transaction& transaction, uint32* pos,
  36                                                 uint32& blockNum, bool& clear);
  37
  38         status_t                _AddBlocks(Transaction& transaction, uint32* block,
  39                                                 off_t count);
  40         status_t                _AddBlocks(Transaction& transaction, uint32* block,
  41                                                 off_t start, off_t end, int recursion);
  42
  43         status_t                _AddForDirectBlocks(Transaction& transaction,
  44                                                 uint32 numBlocks);
  45         status_t                _AddForIndirectBlock(Transaction& transaction,
  46                                                 uint32 numBlocks);
  47         status_t                _AddForDoubleIndirectBlock(Transaction& transaction,
  48                                                 uint32 numBlocks);
  49         status_t                _AddForTripleIndirectBlock(Transaction& transaction,
  50                                                 uint32 numBlocks);
  51
  52         status_t                _PerformFree(Transaction& transaction);
  53         status_t                _MarkBlockForRemoval(Transaction& transaction,
  54                                                 uint32* block);
  55
  56         status_t                _FreeBlocks(Transaction& transaction, uint32* block,
  57                                                 uint32 count);
  58         status_t                _FreeBlocks(Transaction& transaction, uint32* block,
  59                                                 off_t start, off_t end, bool freeParent,
  60                                                 int recursion);
  61
  62         status_t                _RemoveFromDirectBlocks(Transaction& transaction,
  63                                                 uint32 numBlocks);
  64         status_t                _RemoveFromIndirectBlock(Transaction& transaction,
  65                                                 uint32 numBlocks);
  66         status_t                _RemoveFromDoubleIndirectBlock(Transaction& transaction,
  67                                                 uint32 numBlocks);
  68         status_t                _RemoveFromTripleIndirectBlock(Transaction& transaction,
  69                                                 uint32 numBlocks);
  70
  71
  72         const uint32    kBlockSize;
  73         const uint32    kIndirectsPerBlock;
  74         const uint32    kIndirectsPerBlock2;
  75         const uint32    kIndirectsPerBlock3;
  76
  77         const uint32    kMaxDirect;
  78         const uint32    kMaxIndirect;
  79         const uint32    kMaxDoubleIndirect;
  80
  81         Volume*                 fVolume;
  82         ext2_data_stream* fStream;
  83         uint32                  fFirstBlock;
  84
  85         uint32                  fAllocated;
  86         fsblock_t               fAllocatedPos;
  87         uint32                  fWaiting;
  88
  89         uint32                  fFreeStart;
  90         uint32                  fFreeCount;
  91
  92         off_t                   fNumBlocks;
  93         uint32                  fRemovedBlocks;
  94         off_t                   fSize;
  95 };
  96
  97 #endif  // DATASTREAM_H
  98