Refactored query parser to disallow usage of "avg" with incompatible attributes

code/Core/QueryParser.py

@@ -3,17 +3,20 @@ import pyparsing as pp
 
 class QueryParser:
     def __init__(self):
-        # TODO: Try to disallow invalid combinations
-        # TODO: Have tests for invalid combinations
         # TODO: allow lists as input, like: ipaddress(macaddress in [1,2,3])
         extractor = pp.Keyword("random") ^ pp.Keyword("first") ^ pp.Keyword("last")
-        selector = pp.Keyword("most_used") ^ pp.Keyword("least_used") ^ pp.Keyword("avg") ^ pp.Keyword("all")
-        attribute = pp.Keyword("ipaddress") ^ pp.Keyword("macaddress") ^ pp.Keyword("portnumber") ^\
-                    pp.Keyword("protocolname") ^ pp.Keyword("ttlvalue") ^ pp.Keyword("mssvalue") ^\
-                    pp.Keyword("winsize") ^ pp.Keyword("ipclass") ^ pp.Keyword("pktssent") ^\
-                    pp.Keyword("pktsreceived") ^ pp.Keyword("mss") ^ pp.Keyword("kbytesreceived") ^\
-                    pp.Keyword("kbytessent")
-        simple_selector_query = selector + pp.Suppress("(") + attribute + pp.Suppress(")")
+        # Valid selectors - except "avg", because not all attributes can be combined with it
+        selector_no_avg = pp.Keyword("most_used") ^ pp.Keyword("least_used") ^ pp.Keyword("all")
+        attributes_no_avg = pp.Keyword("ipaddress") ^ pp.Keyword("macaddress") ^ pp.Keyword("portnumber") ^\
+                            pp.Keyword("protocolname") ^ pp.Keyword("winsize") ^ pp.Keyword("ipclass")
+
+        attributes_avg = pp.Keyword("ttlvalue") ^ pp.Keyword("mssvalue") ^\
+                         pp.Keyword("pktssent") ^ pp.Keyword("pktsreceived") ^ pp.Keyword("mss") ^\
+                         pp.Keyword("kbytesreceived") ^ pp.Keyword("kbytessent")
+
+        attributes_all = attributes_no_avg ^ attributes_avg
+        simple_selector_query = (selector_no_avg + pp.Suppress("(") + attributes_all + pp.Suppress(")")) ^\
+                                (pp.Keyword("avg") + pp.Suppress("(") + attributes_avg + pp.Suppress(")"))
 
         param_selectors = pp.Keyword("ipaddress").setParseAction(pp.replaceWith("ipaddress_param")) ^\
                           pp.Keyword("macaddress").setParseAction(pp.replaceWith("macaddress_param"))
@@ -21,9 +24,8 @@ class QueryParser:
         operators = pp.Literal("<=") ^ pp.Literal("<") ^ pp.Literal("=") ^\
                     pp.Literal(">=") ^ pp.Literal(">") ^ pp.CaselessLiteral("in")
         expr = pp.Forward()
-        comparison = pp.Group(attribute + operators + (pp.Word(pp.alphanums + ".:") ^ expr))
+        comparison = pp.Group(attributes_all + operators + (pp.Word(pp.alphanums + ".:") ^ expr))
         parameterized_query = param_selectors + pp.Suppress("(") + pp.Group(pp.delimitedList(comparison)) + pp.Suppress(")")
-        # parameterized_query = param_selectors + pp.Suppress("(") + comparison + pp.Suppress(")")
 
         all_selector_queries = (simple_selector_query ^ parameterized_query)
         extractor_selector_query = extractor + pp.Suppress("(") + all_selector_queries + pp.Suppress(")")