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Public Member Functions | Protected Member Functions | Protected Attributes
BufferedBlockDevice Class Reference

#include <BufferedBlockDevice.h>

Inheritance diagram for BufferedBlockDevice:
BlockDevice

Public Member Functions

 BufferedBlockDevice (BlockDevice *bd)
 
virtual ~BufferedBlockDevice ()
 
virtual int init ()
 
virtual int deinit ()
 
virtual int sync ()
 
virtual int read (void *buffer, bd_addr_t addr, bd_size_t size)
 
virtual int program (const void *buffer, bd_addr_t addr, bd_size_t size)
 
virtual int erase (bd_addr_t addr, bd_size_t size)
 
virtual int trim (bd_addr_t addr, bd_size_t size)
 
virtual bd_size_t get_read_size () const
 
virtual bd_size_t get_program_size () const
 
virtual bd_size_t get_erase_size () const
 
virtual bd_size_t get_erase_size (bd_addr_t addr) const
 
virtual int get_erase_value () const
 
virtual bd_size_t size () const
 
- Public Member Functions inherited from BlockDevice
virtual ~BlockDevice ()
 
bool is_valid_read (bd_addr_t addr, bd_size_t size) const
 
bool is_valid_program (bd_addr_t addr, bd_size_t size) const
 
bool is_valid_erase (bd_addr_t addr, bd_size_t size) const
 

Protected Member Functions

int flush ()
 

Protected Attributes

BlockDevice_bd
 
bd_size_t _bd_program_size
 
bd_size_t _curr_aligned_addr
 
bool _flushed
 
uint8_t * _cache
 
uint32_t _init_ref_count
 

Detailed Description

Block device for allowing minimal read and program sizes (of 1) for the underlying BD, using a buffer on the heap.

Constructor & Destructor Documentation

BufferedBlockDevice::BufferedBlockDevice ( BlockDevice bd)

Lifetime of the memory block device

Parameters
bdBlock device to back the BufferedBlockDevice
BufferedBlockDevice::~BufferedBlockDevice ( )
virtual

Lifetime of a block device

Member Function Documentation

int BufferedBlockDevice::deinit ( )
virtual

Deinitialize a block device

Returns
0 on success or a negative error code on failure

Implements BlockDevice.

int BufferedBlockDevice::erase ( bd_addr_t  addr,
bd_size_t  size 
)
virtual

Erase blocks on a block device

The state of an erased block is undefined until it has been programmed, unless get_erase_value returns a non-negative byte value

Parameters
addrAddress of block to begin erasing
sizeSize to erase in bytes, must be a multiple of erase block size
Returns
0 on success, negative error code on failure

Reimplemented from BlockDevice.

int BufferedBlockDevice::flush ( )
protected

Flush data in cache

Returns
0 on success or a negative error code on failure
bd_size_t BufferedBlockDevice::get_erase_size ( ) const
virtual

Get the size of an erasable block

Returns
Size of an erasable block in bytes
Note
Must be a multiple of the program size

Reimplemented from BlockDevice.

bd_size_t BufferedBlockDevice::get_erase_size ( bd_addr_t  addr) const
virtual

Get the size of an erasable block given address

Parameters
addrAddress within the erasable block
Returns
Size of an erasable block in bytes
Note
Must be a multiple of the program size

Reimplemented from BlockDevice.

int BufferedBlockDevice::get_erase_value ( ) const
virtual

Get the value of storage when erased

If get_erase_value returns a non-negative byte value, the underlying storage is set to that value when erased, and storage containing that value can be programmed without another erase.

Returns
The value of storage when erased, or -1 if you can't rely on the value of erased storage

Reimplemented from BlockDevice.

bd_size_t BufferedBlockDevice::get_program_size ( ) const
virtual

Get the size of a programmable block

Returns
Size of a programmable block in bytes
Note
Must be a multiple of the read size

Implements BlockDevice.

bd_size_t BufferedBlockDevice::get_read_size ( ) const
virtual

Get the size of a readable block

Returns
Size of a readable block in bytes

Implements BlockDevice.

int BufferedBlockDevice::init ( )
virtual

Initialize a block device

Returns
0 on success or a negative error code on failure

Implements BlockDevice.

int BufferedBlockDevice::program ( const void *  buffer,
bd_addr_t  addr,
bd_size_t  size 
)
virtual

Program blocks to a block device

The blocks must have been erased prior to being programmed

Parameters
bufferBuffer of data to write to blocks
addrAddress of block to begin writing to
sizeSize to write in bytes, must be a multiple of program block size
Returns
0 on success, negative error code on failure

Implements BlockDevice.

int BufferedBlockDevice::read ( void *  buffer,
bd_addr_t  addr,
bd_size_t  size 
)
virtual

Read blocks from a block device

Parameters
bufferBuffer to read blocks into
addrAddress of block to begin reading from
sizeSize to read in bytes, must be a multiple of read block size
Returns
0 on success, negative error code on failure

Implements BlockDevice.

bd_size_t BufferedBlockDevice::size ( ) const
virtual

Get the total size of the underlying device

Returns
Size of the underlying device in bytes

Implements BlockDevice.

int BufferedBlockDevice::sync ( )
virtual

Ensure data on storage is in sync with the driver

Returns
0 on success or a negative error code on failure

Reimplemented from BlockDevice.

int BufferedBlockDevice::trim ( bd_addr_t  addr,
bd_size_t  size 
)
virtual

Mark blocks as no longer in use

This function provides a hint to the underlying block device that a region of blocks is no longer in use and may be erased without side effects. Erase must still be called before programming, but trimming allows flash-translation-layers to schedule erases when the device is not busy.

Parameters
addrAddress of block to mark as unused
sizeSize to mark as unused in bytes, must be a multiple of erase block size
Returns
0 on success, negative error code on failure

Reimplemented from BlockDevice.


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