/** Return a pointer to the microdescriptor cache, creating (but not loading)
* it if necessary. */
static microdesc_cache_t *
get_microdesc_cache_noload(void)
{
if (PREDICT_UNLIKELY(the_microdesc_cache==NULL)) {
microdesc_cache_t *cache = tor_malloc_zero(sizeof(*cache));
HT_INIT(microdesc_map, &cache->map);
cache->cache_fname = get_cachedir_fname("cached-microdescs");
cache->journal_fname = get_cachedir_fname("cached-microdescs.new");
the_microdesc_cache = cache;
}
return the_microdesc_cache;
}
/**
* Helper: Open a consensus cache in subdirectory <b>subdir</b> of the
* data directory, to hold up to <b>max_entries</b> of data.
*/
consensus_cache_t *
consensus_cache_open(const char *subdir, int max_entries)
{
int storagedir_max_entries;
consensus_cache_t *cache = tor_malloc_zero(sizeof(consensus_cache_t));
char *directory = get_cachedir_fname(subdir);
cache->max_entries = max_entries;
#ifdef MUST_UNMAP_TO_UNLINK
/* If we can't unlink the files that we're still using, then we need to
* tell the storagedir backend to allow far more files than this consensus
* cache actually wants, so that it can hold files which, from this cache's
* perspective, have become useless.
*/
#define VERY_LARGE_STORAGEDIR_LIMIT (1000*1000)
storagedir_max_entries = VERY_LARGE_STORAGEDIR_LIMIT;
#else /* !(defined(MUST_UNMAP_TO_UNLINK)) */
/* Otherwise, we can just tell the storagedir to use the same limits
* as this cache. */
storagedir_max_entries = max_entries;
#endif /* defined(MUST_UNMAP_TO_UNLINK) */
cache->dir = storage_dir_new(directory, storagedir_max_entries);
tor_free(directory);
if (!cache->dir) {
tor_free(cache);
return NULL;
}
consensus_cache_rescan(cache);
return cache;
}
