Struct FatSectorCache 

pub struct FatSectorCache { /* private fields */ }

FAT sector cache with LRU eviction.

This cache stores FAT table sectors in memory to reduce seek operations during cluster chain traversal and allocation.

Implementations

impl FatSectorCache

pub fn new( fat_start: usize, fat_size: usize, fat_count: usize, sector_size: usize, capacity: usize, ) -> Self

Create a new FAT sector cache.

Arguments

• fat_start - Start offset of the FAT in bytes
• fat_size - Size of one FAT copy in bytes
• fat_count - Number of FAT copies (typically 2)
• sector_size - Size of each sector in bytes
• capacity - Maximum number of sectors to cache

pub fn with_default_capacity( fat_start: usize, fat_size: usize, fat_count: usize, sector_size: usize, ) -> Self

Create a cache with default capacity.

pub fn stats(&self) -> CacheStats

Get cache statistics.

pub fn reset_stats(&mut self)

Reset cache statistics.

pub fn clear<T: Read + Write + Seek>( &mut self, writer: Option<&mut T>, ) -> Result<()>

Clear the cache, optionally flushing dirty sectors first.

pub fn len(&self) -> usize

Get the number of cached sectors.

pub fn is_empty(&self) -> bool

Check if the cache is empty.

pub fn flush<T: Write + Seek>(&mut self, writer: &mut T) -> Result<()>

Flush all dirty sectors to disk.

pub fn read_fat12_entry<T: Read + Seek>( &mut self, reader: &mut T, cluster: usize, ) -> Result<u16>

Read a FAT12 entry using the cache.

pub fn write_fat12_entry<T: Read + Write + Seek>( &mut self, io: &mut T, cluster: usize, value: u16, ) -> Result<()>

Write a FAT12 entry through the cache.

Requires Read + Write + Seek because the cache is write-back: an LRU eviction during this call must flush a dirty sector to disk before discarding it.

pub fn read_fat16_entry<T: Read + Seek>( &mut self, reader: &mut T, cluster: usize, ) -> Result<u16>

Read a FAT16 entry using the cache.

pub fn write_fat16_entry<T: Read + Write + Seek>( &mut self, io: &mut T, cluster: usize, value: u16, ) -> Result<()>

Write a FAT16 entry through the cache.

Requires Read + Write + Seek because eviction may flush a dirty sector before discarding it (see Self::write_fat12_entry).

pub fn read_fat32_entry<T: Read + Seek>( &mut self, reader: &mut T, cluster: usize, ) -> Result<u32>

Read a FAT32 entry using the cache.

pub fn write_fat32_entry<T: Read + Write + Seek>( &mut self, io: &mut T, cluster: usize, value: u32, ) -> Result<()>

Write a FAT32 entry through the cache.

Requires Read + Write + Seek because eviction may flush a dirty sector before discarding it (see Self::write_fat12_entry).

Trait Implementations

impl Debug for FatSectorCache

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

Formats the value using the given formatter.