From: Vladimír Čunát <vladimir.cunat@nic.cz>
Date: Sat, 22 Aug 2020 09:47:51 +0000 (+0200)
Subject: lib/cache kr_cdb_api::space_usage(): also use kr_cdb_pt
X-Git-Tag: v5.2.0~37^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9b469602ea8a9cdec38e5fd6d31fab25198dc05a;p=thirdparty%2Fknot-resolver.git

lib/cache kr_cdb_api::space_usage(): also use kr_cdb_pt

- The malloc-free pair could be avoided without difficulty,
  but it seemed like premature optimization.
- The libknot functions make error handling a bit difficult
  (zero is theoretically valid and doesn't show error type),
  but writing this properly without libknot would need 10-20
  additional lines of code and the risk of encountering errors
  in this function seems very low anyway.
---

diff --git a/daemon/bindings/cache.c b/daemon/bindings/cache.c
index 56b75fc93..7b08374e3 100644
--- a/daemon/bindings/cache.c
+++ b/daemon/bindings/cache.c
@@ -3,7 +3,6 @@
  */
 
 #include "daemon/bindings/impl.h"
-#include "lib/cache/cdb_lmdb.h"
 
 #include "daemon/zimport.h"
 
@@ -95,11 +94,9 @@ static int cache_stats(lua_State *L)
 	add_stat(read_leq);
 	add_stat(read_leq_miss);
 	/* usage_percent statistics special case - double */
-	struct libknot_lmdb_env *libknot_db = kr_cdb_pt2knot_db_t(cache->db);
-	cache->stats.usage_percent = cache->api->usage_percent(libknot_db);
+	cache->stats.usage_percent = cache->api->usage_percent(cache->db);
 	lua_pushnumber(L, cache->stats.usage_percent);
 	lua_setfield(L, -2, "usage_percent");
-	free(libknot_db);
 #undef add_stat
 
 	return 1;
diff --git a/lib/cache/cdb_api.h b/lib/cache/cdb_api.h
index 33ec2ffa2..d94ea5e95 100644
--- a/lib/cache/cdb_api.h
+++ b/lib/cache/cdb_api.h
@@ -83,7 +83,8 @@ struct kr_cdb_api {
 	int (*read_leq)(kr_cdb_pt db, struct kr_cdb_stats *stat,
 			knot_db_val_t *key, knot_db_val_t *val);
 
-	double (*usage_percent)(knot_db_t *db);
+	/** Return estimated space usage (0--100). */
+	double (*usage_percent)(kr_cdb_pt db);
 
 	/** Return the current cache size limit in bytes; could be cached by check_health(). */
 	size_t (*get_maxsize)(kr_cdb_pt db);
diff --git a/lib/cache/cdb_lmdb.c b/lib/cache/cdb_lmdb.c
index ff152fb7a..68346480a 100644
--- a/lib/cache/cdb_lmdb.c
+++ b/lib/cache/cdb_lmdb.c
@@ -810,12 +810,13 @@ failure:
 	return lmdb_error(ret);
 }
 
-static double cdb_usage(knot_db_t *db)
+static double cdb_usage_percent(kr_cdb_pt db)
 {
-	const size_t db_size = knot_db_lmdb_get_mapsize(db);
-	const size_t db_usage_abs = knot_db_lmdb_get_usage(db);
+	knot_db_t *kdb = kr_cdb_pt2knot_db_t(db);
+	const size_t db_size = knot_db_lmdb_get_mapsize(kdb);
+	const size_t db_usage_abs = knot_db_lmdb_get_usage(kdb);
 	const double db_usage = (double)db_usage_abs / db_size * 100.0;
-
+	free(kdb);
 	return db_usage;
 }
 
@@ -847,7 +848,7 @@ const struct kr_cdb_api *kr_cdb_lmdb(void)
 		cdb_readv, cdb_writev, cdb_remove,
 		cdb_match,
 		cdb_read_leq,
-		cdb_usage,
+		cdb_usage_percent,
 		cdb_get_maxsize,
 		cdb_check_health,
 	};