Struct MemoryDevice 

pub struct MemoryDevice<const BLOCK_SIZE: u32>(/* private fields */);

In-memory device implementation with configurable block size.

This device stores all data in memory using a Vec<u8> and provides the same interface as physical storage devices. It’s thread-safe and supports all standard device operations. The block size is configurable at compile time through the const generic parameter.

Type Parameters

• Block_size - The block size in bytes (must be a power of 2, typically 512)

Examples

extern crate alloc;
use file_system::{MemoryDevice, DirectBaseOperations, Position};

// Create a 1MB memory device with 512-byte blocks
let device = MemoryDevice::<512>::new(1024 * 1024);

// Write some data
let data = b"Hello, Memory Device!";
device.write(data, 0).unwrap();

// Reset position and read back
device.set_position(0, &Position::Start(0)).unwrap();
let mut buffer = alloc::vec![0u8; data.len()];
device.read(&mut buffer, 0).unwrap();
assert_eq!(&buffer, data);

Thread Safety

The device uses an RwLock to ensure thread-safe access to the underlying data. Multiple readers can access the device simultaneously, but writes are exclusive.

Implementations

impl<const BLOCK_SIZE: u32> MemoryDevice<BLOCK_SIZE>

pub fn new(size: usize) -> Self

Create a new memory device with the specified size.

The device will be initialized with zeros and have the specified total size. The size must be a multiple of the block size.

Arguments

• Size - Total size of the device in bytes

Panics

Panics if Size is not a multiple of Block_size.

Examples

// Create a 4KB device with 512-byte blocks
let device = MemoryDevice::<512>::new(4096);

pub fn new_static(size: usize) -> &'static Self

pub fn from_vec(data: Vec<u8>) -> Self

Create a memory device from existing data.

This allows you to create a device with pre-populated data, useful for testing with known data patterns or loading device images.

Arguments

• Data - Vector containing the initial device data

Panics

Panics if the data length is not a multiple of Block_size.

Examples

// Create device with specific data
let data = vec![0x42; 1024]; // 1KB of 0x42 bytes
let device = MemoryDevice::<512>::from_vec(data);

Trait Implementations

impl<const BLOCK_SIZE: u32> Debug for MemoryDevice<BLOCK_SIZE>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const BLOCK_SIZE: u32> DirectBaseOperations for MemoryDevice<BLOCK_SIZE>

fn read(&self, buffer: &mut [u8], absolute_position: Size) -> Result<usize>

Read data from the memory device.

Reads data from the current position into the provided buffer. The position is automatically advanced by the number of bytes read.

fn write(&self, buffer: &[u8], absolute_position: Size) -> Result<usize>

fn control( &self, command: ControlCommandIdentifier, _: &AnyByLayout, output: &mut AnyByLayout, ) -> Result<()>

fn open(&self) -> Result<()>

fn close(&self) -> Result<()>

fn read_until( &self, buffer: &mut [u8], absolute_position: Size, delimiter: &[u8], ) -> Result<usize>

fn write_pattern( &self, pattern: &[u8], count: usize, absolute_position: Size, ) -> Result<usize>

fn write_vectored( &self, buffers: &[&[u8]], absolute_position: Size, ) -> Result<usize>

fn flush(&self) -> Result<()>

fn set_position( &self, _current_position: Size, _position: &Position, ) -> Result<Size>

impl<const BLOCK_SIZE: u32> DirectBlockDevice for MemoryDevice<BLOCK_SIZE>

fn get_block_size(&self) -> Result<u32>

fn get_block_count(&self) -> Result<Size>

impl<const BLOCK_SIZE: u32> MountOperations for MemoryDevice<BLOCK_SIZE>

fn mount(&self) -> Result<()>

fn unmount(&self) -> Result<()>