From: Petr Špaček <petr.spacek@nic.cz>
Date: Wed, 15 Aug 2018 15:53:29 +0000 (+0200)
Subject: cache: return number of removed entries from remove_* functions
X-Git-Tag: v3.0.0~1^2~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6a8e28b844f3f58fb016bba46b65898a3dc5cc91;p=thirdparty%2Fknot-resolver.git

cache: return number of removed entries from remove_* functions

It is more convenient to return 0 instead of ENOENT.
---

diff --git a/lib/cache/api.c b/lib/cache/api.c
index eae62d401..a3e3bb794 100644
--- a/lib/cache/api.c
+++ b/lib/cache/api.c
@@ -775,13 +775,7 @@ int kr_cache_remove(struct kr_cache *cache, const knot_dname_t *name, uint16_t t
 	if (ret) return kr_error(ret);
 
 	knot_db_val_t key = key_exact_type(k, type);
-	ret = cache_op(cache, remove, &key, 1);
-	switch (ret) {
-		case 0: return 1;
-		case -ABS(ENOENT): return 0;
-		default: return ret;
-	}
-
+	return cache_op(cache, remove, &key, 1);
 }
 
 int kr_cache_match(struct kr_cache *cache, const knot_dname_t *name,
@@ -852,8 +846,8 @@ int kr_cache_remove_subtree(struct kr_cache *cache, const knot_dname_t *name,
 
 	knot_db_val_t keyval[maxcount][2], keys[maxcount];
 	int ret = kr_cache_match(cache, name, exact_name, keyval, maxcount);
-	if (ret < 0) {
-		return ret;
+	if (ret <= 0) { /* ENOENT -> nothing to remove */
+		return (ret == KNOT_ENOENT) ? 0 : ret;
 	}
 	const int count = ret;
 	/* Duplicate the key strings, as deletion may invalidate the pointers. */
@@ -874,6 +868,6 @@ cleanup:
 	while (--i >= 0) {
 		free(keys[i].data);
 	}
-	return ret ? ret : count;
+	return ret;
 }
 
diff --git a/lib/cache/api.h b/lib/cache/api.h
index 72751ce38..9034fa182 100644
--- a/lib/cache/api.h
+++ b/lib/cache/api.h
@@ -166,6 +166,7 @@ int kr_cache_match(struct kr_cache *cache, const knot_dname_t *name,
 
 /**
  * Remove a subtree in cache.  It's like _match but removing them instead of returning.
+ * @return number of deleted entries or an errcode
  */
 KR_EXPORT
 int kr_cache_remove_subtree(struct kr_cache *cache, const knot_dname_t *name,
diff --git a/lib/cache/cdb_api.h b/lib/cache/cdb_api.h
index 8836d57a2..814a5f5dd 100644
--- a/lib/cache/cdb_api.h
+++ b/lib/cache/cdb_api.h
@@ -47,7 +47,10 @@ struct kr_cdb_api {
 			int maxcount);
 	int (*write)(knot_db_t *db, const knot_db_val_t *key, knot_db_val_t *val,
 			int maxcount);
-	/** Remove maxcount keys.  Return error code.  (Returns on first error.) */
+
+	/** Remove maxcount keys.
+	 * \returns the number of succesfully removed keys or the first error code
+	 * It returns on first error, but ENOENT is not considered an error. */
 	int (*remove)(knot_db_t *db, knot_db_val_t keys[], int maxcount);
 
 	/* Specialised operations */
diff --git a/lib/cache/cdb_lmdb.c b/lib/cache/cdb_lmdb.c
index e4e323638..621d2e881 100644
--- a/lib/cache/cdb_lmdb.c
+++ b/lib/cache/cdb_lmdb.c
@@ -552,14 +552,19 @@ static int cdb_remove(knot_db_t *db, knot_db_val_t keys[], int maxcount)
 	struct lmdb_env *env = db;
 	MDB_txn *txn = NULL;
 	int ret = txn_get(env, &txn, false);
+	int deleted = 0;
 
 	for (int i = 0; ret == kr_ok() && i < maxcount; ++i) {
 		MDB_val _key = val_knot2mdb(keys[i]);
 		MDB_val val = { 0, NULL };
 		ret = lmdb_error(mdb_del(txn, env->dbi, &_key, &val));
+		if (ret == kr_ok())
+			deleted++;
+		else if (ret == KNOT_ENOENT)
+			ret = kr_ok();  /* skip over non-existing entries */
 	}
 
-	return ret;
+	return ret < 0 ? ret : deleted;
 }
 
 static int cdb_match(knot_db_t *db, knot_db_val_t *key, knot_db_val_t keyval[][2], int maxcount)