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FatCache Class Reference

Block cache. More...

`#include <FatVolume.h>`

## Public Member Functions
cache_t * | block ()
void | dirty ()
void | init (FatVolume *vol)
void | invalidate ()
uint32_t | lbn ()
cache_t * | read (uint32_t lbn, uint8_t option)
bool | sync ()

## Static Public Attributes
static const uint8_t | CACHE_FOR_READ = 0
static const uint8_t | CACHE_FOR_WRITE = CACHE_STATUS_DIRTY
static const uint8_t | CACHE_OPTION_NO_READ = 4
static const uint8_t | CACHE_RESERVE_FOR_WRITE = CACHE_STATUS_DIRTY | CACHE_OPTION_NO_READ
static const uint8_t | CACHE_STATUS_DIRTY = 1
static const uint8_t | CACHE_STATUS_MASK = CACHE_STATUS_DIRTY | CACHE_STATUS_MIRROR_FAT
static const uint8_t | CACHE_STATUS_MIRROR_FAT = 2

## Detailed Description

Block cache.

## Member Function Documentation

cache_t* FatCache::block | ( |  | ) |
| inline

Returns
  Cache block address.

void FatCache::dirty | ( |  | ) |
| inline

Set current block dirty.

void FatCache::init | ( | FatVolume * | vol | ) |
| inline

Initialize the cache.

Parameters

  [in] | vol | FatVolume that owns this FatCache.

void FatCache::invalidate | ( |  | ) |
| inline

Invalidate current cache block.

uint32_t FatCache::lbn | ( |  | ) |
| inline

Returns
  Logical block number for cached block.

cache_t * FatCache::read | ( | uint32_t | lbn,
|  | uint8_t | option
| ) |  |

Read a block into the cache.

Parameters

  [in] | lbn | Block to read.
  [in] | option | mode for cached block.

Returns
  Address of cached block.

bool FatCache::sync | ( |  | ) |

Write current block if dirty.

Returns
  true for success else false.

## Member Data Documentation

const uint8_t FatCache::CACHE_FOR_READ = 0
| static

Cache block for read.

const uint8_t FatCache::CACHE_FOR_WRITE = CACHE_STATUS_DIRTY
| static

Cache block for write.

const uint8_t FatCache::CACHE_OPTION_NO_READ = 4
| static

Sync existing block but do not read new block.

const uint8_t FatCache::CACHE_RESERVE_FOR_WRITE = CACHE_STATUS_DIRTY | CACHE_OPTION_NO_READ
| static

Reserve cache block for write - do not read from block device.

const uint8_t FatCache::CACHE_STATUS_DIRTY = 1
| static

Cached block is dirty

const uint8_t FatCache::CACHE_STATUS_MASK = CACHE_STATUS_DIRTY | CACHE_STATUS_MIRROR_FAT
| static

Cache block status bits

const uint8_t FatCache::CACHE_STATUS_MIRROR_FAT = 2
| static

Cashed block is FAT entry and must be mirrored in second FAT.

The documentation for this class was generated from the following files:

- Arduino/libraries/SdFat/src/FatLib/FatVolume.h
- Arduino/libraries/SdFat/src/FatLib/FatVolume.cpp