cas_cache: Generic classifier for string conditions.

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>

modules/cas_cache/classifier_defs.h

@@ -6,6 +6,8 @@
 #ifndef __CLASSIFIER_DEFS_H__
 #define __CLASSIFIER_DEFS_H__
 
+#define MAX_STRING_SPECIFIER_LEN 256
+
 /* Rule matches 1:1 with io class. It contains multiple conditions with
  * associated logical operator (and/or) */
 struct cas_cls_rule {
@@ -118,6 +120,12 @@ struct cas_cls_numeric {
 	uint64_t v_u64;
 };
 
+/* String condition context */
+struct cas_cls_string {
+	/* String specifier*/
+	char string[MAX_STRING_SPECIFIER_LEN];
+};
+
 /* Directory condition context */
 struct cas_cls_directory {
 	/* 1 if directory had been resolved */