SdFat: FsCache Class Reference

SdFat

Public Member Functions | Static Public Attributes | List of all members
FsCache Class Reference

Sector cache. More...

`#include <FsCache.h>`

## Public Member Functions
uint8_t * | cacheBuffer ()
bool | cacheSafeRead (uint32_t sector, uint8_t *dst)
bool | cacheSafeRead (uint32_t sector, uint8_t *dst, size_t count)
bool | cacheSafeWrite (uint32_t sector, const uint8_t *src)
bool | cacheSafeWrite (uint32_t sector, const uint8_t *src, size_t count)
uint8_t * | clear ()
void | dirty ()
uint8_t * | get (uint32_t sector, uint8_t option)
void | init (BlockDevice *blockDev)
void | invalidate ()
bool | isCached (uint32_t sector) const
bool | isCached (uint32_t sector, size_t count)
bool | isDirty ()
uint32_t | sector ()
void | setMirrorOffset (uint32_t offset)
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
static const uint8_t | CACHE_STATUS_DIRTY = 1
static const uint8_t | CACHE_STATUS_MASK
static const uint8_t | CACHE_STATUS_MIRROR_FAT = 2

## Detailed Description

Sector cache.

## Member Function Documentation

## ◆ cacheBuffer()

uint8_t* FsCache::cacheBuffer | ( |  | ) |
| inline

Returns
  Cache buffer address.

## ◆ cacheSafeRead() [1/2]

bool FsCache::cacheSafeRead | ( | uint32_t | sector,
|  | uint8_t * | dst
| ) |  |
| inline

Cache safe read of a sector.

Parameters

  [in] | sector | Logical sector to be read.
  [out] | dst | Pointer to the location that will receive the data.

Returns
  true for success or false for failure.

## ◆ cacheSafeRead() [2/2]

bool FsCache::cacheSafeRead | ( | uint32_t | sector,
|  | uint8_t * | dst,
|  | size_t | count
| ) |  |
| inline

Cache safe read of multiple sectors.

Parameters

  [in] | sector | Logical sector to be read.
  [in] | count | Number of sectors to be read.
  [out] | dst | Pointer to the location that will receive the data.

Returns
  true for success or false for failure.

## ◆ cacheSafeWrite() [1/2]

bool FsCache::cacheSafeWrite | ( | uint32_t | sector,
|  | const uint8_t * | src
| ) |  |
| inline

Cache safe write of a sectors.

Parameters

  [in] | sector | Logical sector to be written.
  [in] | src | Pointer to the location of the data to be written.

Returns
  true for success or false for failure.

## ◆ cacheSafeWrite() [2/2]

bool FsCache::cacheSafeWrite | ( | uint32_t | sector,
|  | const uint8_t * | src,
|  | size_t | count
| ) |  |
| inline

Cache safe write of multiple sectors.

Parameters

  [in] | sector | Logical sector to be written.
  [in] | src | Pointer to the location of the data to be written.
  [in] | count | Number of sectors to be written.

Returns
  true for success or false for failure.

## ◆ clear()

uint8_t* FsCache::clear | ( |  | ) |
| inline

Returns
  Clear the cache and returns a pointer to the cache.

## ◆ dirty()

void FsCache::dirty | ( |  | ) |
| inline

Set current sector dirty.

## ◆ get()

uint8_t * FsCache::get | ( | uint32_t | sector,
|  | uint8_t | option
| ) |  |

Fill cache with sector data.

Parameters

  [in] | sector | Sector to read.
  [in] | option | mode for cached sector.

Returns
  Address of cached sector.

## ◆ init()

void FsCache::init | ( | BlockDevice * | blockDev | ) |
| inline

Initialize the cache.

Parameters

  [in] | blockDev | Block device for this cache.

## ◆ invalidate()

void FsCache::invalidate | ( |  | ) |
| inline

Invalidate current cache sector.

## ◆ isCached() [1/2]

bool FsCache::isCached | ( | uint32_t | sector | ) | const
| inline

Check if a sector is in the cache.

Parameters

  [in] | sector | Sector to checked.

Returns
  true if the sector is cached.

## ◆ isCached() [2/2]

bool FsCache::isCached | ( | uint32_t | sector,
|  | size_t | count
| ) |  |
| inline

Check if the cache contains a sector from a range.

Parameters

  [in] | sector | Start sector of the range.
  [in] | count | Number of sectors in the range.

Returns
  true if a sector in the range is cached.

## ◆ isDirty()

bool FsCache::isDirty | ( |  | ) |
| inline

Returns
  dirty status

## ◆ sector()

uint32_t FsCache::sector | ( |  | ) |
| inline

Returns
  Logical sector number for cached sector.

## ◆ setMirrorOffset()

void FsCache::setMirrorOffset | ( | uint32_t | offset | ) |
| inline

Set the offset to the second FAT for mirroring.

Parameters

  [in] | offset | Sector offset to second FAT.

## ◆ sync()

bool FsCache::sync | ( |  | ) |

Write current sector if dirty.

Returns
  true for success or false for failure.

## Member Data Documentation

## ◆ CACHE_FOR_READ

const uint8_t FsCache::CACHE_FOR_READ = 0
| static

Cache sector for read.

## ◆ CACHE_FOR_WRITE

const uint8_t FsCache::CACHE_FOR_WRITE = CACHE_STATUS_DIRTY
| static

Cache sector for write.

## ◆ CACHE_OPTION_NO_READ

const uint8_t FsCache::CACHE_OPTION_NO_READ = 4
| static

Sync existing sector but do not read new sector.

## ◆ CACHE_RESERVE_FOR_WRITE

const uint8_t FsCache::CACHE_RESERVE_FOR_WRITE
| static

Initial value:
=
CACHE_STATUS_DIRTY | CACHE_OPTION_NO_READ

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

## ◆ CACHE_STATUS_DIRTY

const uint8_t FsCache::CACHE_STATUS_DIRTY = 1
| static

Cached sector is dirty

## ◆ CACHE_STATUS_MASK

const uint8_t FsCache::CACHE_STATUS_MASK
| static

Initial value:
=
CACHE_STATUS_DIRTY | CACHE_STATUS_MIRROR_FAT

Cache sector status bits

## ◆ CACHE_STATUS_MIRROR_FAT

const uint8_t FsCache::CACHE_STATUS_MIRROR_FAT = 2
| static

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

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

- ArduinoSdFat/libraries/SdFat/src/common/FsCache.h
- ArduinoSdFat/libraries/SdFat/src/common/FsCache.cpp

FsCache::CACHE_STATUS_MIRROR_FAT
static const uint8_t CACHE_STATUS_MIRROR_FAT
Definition: FsCache.h:42
FsCache::CACHE_OPTION_NO_READ
static const uint8_t CACHE_OPTION_NO_READ
Definition: FsCache.h:47
FsCache::CACHE_STATUS_DIRTY
static const uint8_t CACHE_STATUS_DIRTY
Definition: FsCache.h:40