lru.h File Reference

#include <stddef.h>
#include <stdint.h>
#include <uthash.h>

Go to the source code of this file.

Data Structures
struct	CacheEntry
	Single hash entry in the in-memory cache. More...
struct	CacheHeader
	Cache top-level descriptor encapsulating the hash table root and capacity limit. More...

Functions
void *	find_in_cache_uint64 (struct CacheHeader *cache, uint64_t key)
	Finds a value in the cache by uint64_t key.
void	add_to_cache_uint64 (struct CacheHeader *cache, uint64_t key, void *value, size_t size)
	Adds a value to the cache with a uint64_t key, evicting LRU entries if over budget.
void	free_cache (struct CacheHeader *cache)
	Frees all entries in the cache and clears it.

Function Documentation

add_to_cache_uint64()

void add_to_cache_uint64	(	struct CacheHeader *	cache,
		const uint64_t	key,
		void *	value,
		const size_t	size )

Adds a value to the cache with a uint64_t key, evicting LRU entries if over budget.

Adds a new entry to the cache. If an entry with the same key is already present, its value is freed and replaced. If the cache exceeds its memory budget, the least recently used entries are evicted until it fits again. The entry just inserted is never evicted, so the caller may keep using the pointer it handed over for the remainder of the call.

Parameters

cache	Pointer to the cache header.
key	64-bit integer key to add.
value	Pointer to the value to store.
size	Size in bytes of the memory pointed to by value.

Definition at line 68 of file lru.c.

References add_to_cache_uint64(), CacheHeader::cache, CacheHeader::cur_bytes, drop_entry(), CacheHeader::free_func, CacheEntry::hh, CacheEntry::key, CacheHeader::max_bytes, CacheEntry::size, and CacheEntry::value.

Referenced by aaruf_read_sector(), add_to_cache_uint64(), and ec_recover_data_block().

find_in_cache_uint64()

void * find_in_cache_uint64	(	struct CacheHeader *	cache,
		const uint64_t	key )

Finds a value in the cache by uint64_t key.

Searches for a value using a native 64-bit integer key and promotes it to the front of the insertion-order list (LRU refresh) if found.

Parameters

cache	Pointer to the cache header.
key	64-bit integer key to search for.

Returns

Pointer to the value if found, or NULL if not found.

Definition at line 41 of file lru.c.

References CacheHeader::cache, find_in_cache_uint64(), CacheEntry::hh, CacheEntry::key, and CacheEntry::value.

Referenced by aaruf_read_sector(), and find_in_cache_uint64().

free_cache()

void free_cache

(

struct CacheHeader *

cache

)

Frees all entries in the cache and clears it.

Iterates through all cache entries, frees them, then clears the hash table. Uses the cache's free_func if set to free cached values.

Parameters

cache

Pointer to the cache header.

Definition at line 118 of file lru.c.

References CacheHeader::cache, CacheHeader::cur_bytes, drop_entry(), free_cache(), and CacheEntry::hh.

Referenced by aaruf_close(), and free_cache().