Struct InodeLruCache 

struct InodeLruCache {
    map: HashMap<u32, u32>,
    nodes: HashMap<u32, InodeLruNode>,
    head: Option<u32>,
    tail: Option<u32>,
    next_id: u32,
    max_size: usize,
    hits: u64,
    misses: u64,
    access_counter: u64,
}

O(1) LRU cache implementation for inodes using HashMap + doubly-linked list

Fields

map: HashMap<u32, u32>

Map from inode number to node ID

nodes: HashMap<u32, InodeLruNode>

Storage for all nodes

head: Option<u32>

Head of doubly-linked list (most recently used)

tail: Option<u32>

Tail of doubly-linked list (least recently used)

next_id: u32

Next available node ID

max_size: usize

Maximum cache size

hits: u64

Cache statistics

misses: u64

access_counter: u64

Access counter for approximate LRU

Implementations

impl InodeLruCache

fn new(max_size: usize) -> Self

fn get(&mut self, inode_num: u32) -> Option<Ext2Inode>

O(1) get operation with LRU update

fn insert(&mut self, inode_num: u32, inode: Ext2Inode)

O(1) insert operation with LRU eviction

fn remove(&mut self, inode_num: u32)

O(1) remove operation

fn move_to_head(&mut self, node_id: u32)

O(1) move node to head of LRU list

fn remove_tail(&mut self)

O(1) remove tail (LRU) node

fn remove_node(&mut self, node_id: u32)

O(1) remove node completely

fn remove_node_from_list(&mut self, node_id: u32)

O(1) remove node from doubly-linked list (but keep in nodes map)

fn len(&self) -> usize

fn get_stats(&self) -> (u64, u64, usize)

Get cache statistics for debugging and performance analysis

fn print_stats(&self, cache_name: &str)

Print cache statistics