[Feature] Fix order of pre and postfilters

Prefilters are executed in order inverse to their priorities, e.g.
prefilter with priority 10 will be called before prefilter witj priority
0.

Postfilters are executed in the opposite order: so postfilter with
priority 10 will be executed after postfilter with priority 0.

It is also possible to specify negative priorities for pre and post
filters to inverse this logic.

1 files changed, 42 insertions, 2 deletions

diff --git a/src/libserver/symbols_cache.c b/src/libserver/symbols_cache.c
index a01b95d42..c69a59383 100644
--- a/src/libserver/symbols_cache.c
+++ b/src/libserver/symbols_cache.c
@@ -210,6 +210,46 @@ rspamd_symbols_cache_order_new (gsize nelts)
 }
 
 static gint
+postfilters_cmp (const void *p1, const void *p2, gpointer ud)
+{
+	const struct cache_item *i1 = *(struct cache_item **)p1,
+			*i2 = *(struct cache_item **)p2;
+	double w1, w2;
+
+	w1 = i1->priority;
+	w2 = i2->priority;
+
+	if (w1 > w2) {
+		return 1;
+	}
+	else if (w1 < w2) {
+		return -1;
+	}
+
+	return 0;
+}
+
+static gint
+prefilters_cmp (const void *p1, const void *p2, gpointer ud)
+{
+	const struct cache_item *i1 = *(struct cache_item **)p1,
+			*i2 = *(struct cache_item **)p2;
+	double w1, w2;
+
+	w1 = i1->priority;
+	w2 = i2->priority;
+
+	if (w1 < w2) {
+		return 1;
+	}
+	else if (w1 > w2) {
+		return -1;
+	}
+
+	return 0;
+}
+
+static gint
 cache_logic_cmp (const void *p1, const void *p2, gpointer ud)
 {
 	const struct cache_item *i1 = *(struct cache_item **)p1,
@@ -404,8 +444,8 @@ rspamd_symbols_cache_post_init (struct symbols_cache *cache)
 		}
 	}
 
-	g_ptr_array_sort_with_data (cache->prefilters, cache_logic_cmp, cache);
-	g_ptr_array_sort_with_data (cache->postfilters, cache_logic_cmp, cache);
+	g_ptr_array_sort_with_data (cache->prefilters, prefilters_cmp, cache);
+	g_ptr_array_sort_with_data (cache->postfilters, postfilters_cmp, cache);
 }
 
 static gboolean