int dict_cache_delete(DICT_CACHE *cp, const char *cache_key)
{
const char *myname = "dict_cache_delete";
int del_res;
DICT *db = cp->db;
/*
* Delete the entry, unless we would delete the current first/next entry.
* In that case, schedule the "current" entry for delete-behind to avoid
* mis-behavior by some databases.
*/
if (DC_MATCH_SAVED_CURRENT_KEY(cp, cache_key)) {
DC_SCHEDULE_FOR_DELETE_BEHIND(cp);
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: key=%s (current entry - schedule for delete-behind)",
myname, cache_key);
DICT_ERR_VAL_RETURN(cp, DICT_ERR_NONE, DICT_STAT_SUCCESS);
} else {
del_res = dict_del(db, cache_key);
if (del_res != 0)
msg_rate_delay(&cp->del_log_stamp, cp->log_delay, msg_warn,
"%s: could not delete entry for %s", cp->name, cache_key);
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: key=%s (%s)", myname, cache_key,
del_res == 0 ? "found" :
db->error ? "error" : "not found");
DICT_ERR_VAL_RETURN(cp, db->error, del_res);
}
}
int dict_cache_delete(DICT_CACHE *cp, const char *cache_key)
{
const char *myname = "dict_cache_delete";
int zero_means_found;
/*
* Delete the entry, unless we would delete the current first/next entry.
* In that case, schedule the "current" entry for delete-behind to avoid
* mis-behavior by some databases.
*/
if (DC_MATCH_SAVED_CURRENT_KEY(cp, cache_key)) {
DC_SCHEDULE_FOR_DELETE_BEHIND(cp);
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: key=%s (current entry - schedule for delete-behind)",
myname, cache_key);
zero_means_found = 0;
} else {
zero_means_found = dict_del(cp->db, cache_key);
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: key=%s (%s)", myname, cache_key,
zero_means_found == 0 ? "found" : "not found");
}
return (zero_means_found);
}
static void dict_cache_clean_event(int unused_event, char *cache_context)
{
const char *myname = "dict_cache_clean_event";
DICT_CACHE *cp = (DICT_CACHE *) cache_context;
const char *cache_key;
const char *cache_val;
int next_interval;
VSTRING *stamp_buf;
int first_next;
/*
* We interleave cache cleanup with other processing, so that the
* application's service remains available, with perhaps increased
* latency.
*/
/*
* Start a new cache cleanup run.
*/
if (cp->saved_curr_key == 0) {
cp->retained = cp->dropped = 0;
first_next = DICT_SEQ_FUN_FIRST;
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: start %s cache cleanup", myname, cp->name);
}
/*
* Continue a cache cleanup run in progress.
*/
else {
first_next = DICT_SEQ_FUN_NEXT;
}
/*
* Examine one cache entry.
*/
if (dict_cache_sequence(cp, first_next, &cache_key, &cache_val) == 0) {
if (cp->exp_validator(cache_key, cache_val, cp->exp_context) == 0) {
DC_SCHEDULE_FOR_DELETE_BEHIND(cp);
cp->dropped++;
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: drop %s cache entry for %s",
myname, cp->name, cache_key);
} else {
cp->retained++;
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: keep %s cache entry for %s",
myname, cp->name, cache_key);
}
next_interval = 0;
}
/*
* Cache cleanup completed. Report vital statistics.
*/
else if (cp->error != 0) {
msg_warn("%s: cache cleanup scan terminated due to error", cp->name);
dict_cache_clean_stat_log_reset(cp, "partial");
next_interval = cp->exp_interval;
} else {
if (cp->user_flags & DICT_CACHE_FLAG_VERBOSE)
msg_info("%s: done %s cache cleanup scan", myname, cp->name);
dict_cache_clean_stat_log_reset(cp, "full");
stamp_buf = vstring_alloc(100);
vstring_sprintf(stamp_buf, "%ld", (long) event_time());
dict_put(cp->db, DC_LAST_CACHE_CLEANUP_COMPLETED,
vstring_str(stamp_buf));
vstring_free(stamp_buf);
next_interval = cp->exp_interval;
}
event_request_timer(dict_cache_clean_event, cache_context, next_interval);
}
