From 318e2e6d604927bf63abc1f76cd034c61d8e8e49 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Tue, 24 Nov 2009 09:59:54 -0800 Subject: [PATCH] classifier: Improve comments. --- lib/classifier.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/lib/classifier.h b/lib/classifier.h index 8b095e91..194b04e6 100644 --- a/lib/classifier.h +++ b/lib/classifier.h @@ -25,6 +25,20 @@ * fields after F tend to be wildcarded as well. If this assumption is * violated, then the classifier will still classify flows correctly, but its * performance will suffer. + * + * The classifier uses a collection of CLS_N_FIELDS hash tables for wildcarded + * flows. Each of these tables contains the flows that wildcard a given field + * and do not wildcard any of the fields that precede F in the ordering. The + * key for each hash table is the value of the fields preceding F that are not + * wildcarded. All the flows that fall within a table and have the same key + * are kept as a linked list ordered from highest to lowest priority. + * + * The classifier also maintains a separate hash table of exact-match flows. + * + * To search the classifier we first search the table of exact-match flows, + * since exact-match flows always have highest priority. If there is a match, + * we're done. Otherwise, we search each of the CLS_N_FIELDS hash tables in + * turn, looking for the highest-priority match, and return it (if any). */ #include "flow.h" -- 2.30.2