X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fclassifier.h;h=194b04e6b3b18a6b071fd427141e1b64ccf490ca;hb=2f47998baea215b996af0be4d1653032005e3ac4;hp=a632fb02452b7b71459e3ddd277a8d9d04d8833f;hpb=064af42167bf4fc9aaea2702d80ce08074b889c0;p=sliver-openvswitch.git

diff --git a/lib/classifier.h b/lib/classifier.h
index a632fb024..194b04e6b 100644
--- a/lib/classifier.h
+++ b/lib/classifier.h
@@ -1,17 +1,17 @@
 /*
  * Copyright (c) 2009 Nicira Networks.
  *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
  *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  */
 
 #ifndef 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"