cache garbage collector

Experimental code for cache GC.

I've set the defaults to values that seemed to work well (clear about ~10% of cache when 80% full, use 100 operations per transaction). Higher values for allowed cache usage didn't seem to properly prevent complete cache flush. High values of ops per transaction (or unlimited) caused issues as well.

Closes #257 (closed)

utils/kr_cache_gc/kr_cache_gc.c

@@ -60,8 +60,8 @@ static knot_db_val_t *dbval_copy(const knot_db_val_t *from)
 
 // section: rrtype list
 
-dynarray_declare(rrtype, uint16_t, DYNARRAY_VISIBILITY_STATIC, 64);
-dynarray_define(rrtype, uint16_t, DYNARRAY_VISIBILITY_STATIC);
+dynarray_declare(rrtype, uint16_t, DYNARRAY_VISIBILITY_STATIC, 64)
+dynarray_define(rrtype, uint16_t, DYNARRAY_VISIBILITY_STATIC)
 
 static void rrtypelist_add(rrtype_dynarray_t *arr, uint16_t add_type)
 {
@@ -87,8 +87,8 @@ static void rrtypelist_print(rrtype_dynarray_t *arr)
 	printf("\n");
 }
 
-dynarray_declare(entry, knot_db_val_t*, DYNARRAY_VISIBILITY_STATIC, 256);
-dynarray_define(entry, knot_db_val_t*, DYNARRAY_VISIBILITY_STATIC);
+dynarray_declare(entry, knot_db_val_t*, DYNARRAY_VISIBILITY_STATIC, 256)
+dynarray_define(entry, knot_db_val_t*, DYNARRAY_VISIBILITY_STATIC)
 static void entry_dynarray_deep_free(entry_dynarray_t *d)
 {
 	dynarray_foreach(entry, knot_db_val_t*, i, *d) {
@@ -158,7 +158,7 @@ int kr_cache_gc(kr_cache_gc_cfg_t *cfg)
 	gc_timer_t timer_analyze = { 0 }, timer_choose = { 0 }, timer_delete = { 0 }, timer_rw_txn = { 0 };
 
 	gc_timer_start(&timer_analyze);
-	ctx_compute_categories_t cats = { 0 };
+	ctx_compute_categories_t cats = {{ 0 }};
 	ret = kr_gc_cache_iter(db, cb_compute_categories, &cats);
 	if (ret != KNOT_EOK) {
 		kr_gc_cache_close(&kres_db, db);