A bounded cache of files in one directory, keyed by content. More...

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "nilorea/n_disk_cache.h"
#include "nilorea/n_hash.h"
#include "nilorea/n_log.h"
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>

Include dependency graph for n_disk_cache.c:

Data Structures
struct	_N_DC_ENTRY
	one entry found by a walk of the directory More...
struct	_N_DC_GROUP_ENTRY
	one entry of a group prune: the entry and the cache it is in More...
struct	N_DISK_CACHE
	a cache: only where it is More...

Macros
#define	N_DISK_CACHE_PATH_MAX 4096
	longest path this module builds
#define	N_DISK_CACHE_SEED 0x4E444331u
	seed of the key hash.

Functions
static FILE *	_n_dc_fopen (const char path, const char mode)
	helper: fopen a UTF-8 path
static int	_n_dc_group_older (const void a, const void b)
	qsort order for a group: least recently used first
static int	_n_dc_is_dir (const char *path)
	helper: is `path` a directory
static int	_n_dc_join (const N_DISK_CACHE cache, const char name, char *out, size_t out_len)
	helper: join the directory and a file name
static int	_n_dc_older (const void a, const void b)
	qsort order: least recently used first
static int	_n_dc_owned (const char *name)
	helper: is `name` one this module could have made: 32 lowercase hex digits, then the end or a '.
static int	_n_dc_remove (const char *path)
	helper: remove a UTF-8 path.
static int	_n_dc_replace (const char from, const char to)
	helper: rename over an existing target
static int	_n_dc_walk (const N_DISK_CACHE cache, _N_DC_ENTRY *out)
	helper: every entry of the cache, in a new array the caller frees.
void	n_disk_cache_close (N_DISK_CACHE **cache)
	Forget a cache.
const char *	n_disk_cache_dir (const N_DISK_CACHE *cache)
	The cache's directory, as it was opened.
int	n_disk_cache_expire (const N_DISK_CACHE *cache, int64_t max_age_seconds)
	Remove every entry unused for longer than an age.
int	n_disk_cache_get (const N_DISK_CACHE cache, const void key, size_t key_len, const char ext, size_t max_len, unsigned char data, size_t len)
	Read an entry.
N_DISK_CACHE *	n_disk_cache_open (const char *dir)
	Use a directory as a cache.
int	n_disk_cache_path (const N_DISK_CACHE cache, const void key, size_t key_len, const char ext, char out, size_t out_len)
	The file an entry lives in, whether or not it exists.
int	n_disk_cache_prune (const N_DISK_CACHE *cache, uint64_t max_bytes)
	Remove least recently used entries until the rest fit a budget.
int	n_disk_cache_prune_group (const N_DISK_CACHE const caches, int count, uint64_t max_bytes)
	n_disk_cache_prune() over several caches that share one budget.
int	n_disk_cache_put (const N_DISK_CACHE cache, const void key, size_t key_len, const char ext, const void data, size_t len)
	Store an entry, replacing any under the same key and extension.
int	n_disk_cache_remove (const N_DISK_CACHE cache, const void key, size_t key_len, const char *ext)
	Remove one entry, for a caller that found it unreadable.
int	n_disk_cache_size (const N_DISK_CACHE cache, uint64_t total)
	How many bytes the cache's entries take.