MXS-1992 Allow the setting/getting of cache size at runtime

include/maxscale/query_classifier.h

@@ -863,6 +863,22 @@ void qc_set_server_version(uint64_t version);
  */
 uint64_t qc_get_server_version();
 
+/**
+ * Get the cache properties.
+ *
+ * @param properties[out]  Cache properties.
+ *
+ * @return True, if caching is enabled, false otherwise.
+ */
+bool qc_get_cache_properties(QC_CACHE_PROPERTIES* properties);
+
+/**
+ * Set the cache properties.
+ *
+ * @param properties[in]  Cache properties.
+ */
+void qc_set_cache_properties(const QC_CACHE_PROPERTIES* properties);
+
 /**
  * Get cache statistics for the calling thread.
  *