ONOS-6605 PI flow rule translator implementation
Change-Id: Icac66f17677c494152207f4b52355ad647e1227b
diff --git a/core/net/src/main/java/org/onosproject/net/pi/impl/CriterionTranslator.java b/core/net/src/main/java/org/onosproject/net/pi/impl/CriterionTranslator.java
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+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * 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
+ *
+ * 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.
+ */
+
+package org.onosproject.net.pi.impl;
+
+
+import org.apache.commons.lang3.tuple.Pair;
+import org.onlab.util.ImmutableByteSequence;
+import org.onosproject.net.flow.criteria.Criterion;
+
+import static org.onlab.util.ImmutableByteSequence.ByteSequenceTrimException;
+
+/**
+ * A translator of a criterion instance to different match types represented as primitive byte sequences.
+ */
+interface CriterionTranslator {
+
+ /**
+ * Initialize this translator with the given criterion and field match bit-width.
+ *
+ * @param criterion criterion
+ * @param bitWidth field bit-width
+ * @throws ByteSequenceTrimException if the criterion cannot be trimmed to fit the field match bit-width
+ */
+ void init(Criterion criterion, int bitWidth) throws ByteSequenceTrimException;
+
+ /**
+ * Returns a pair of byte sequences representing a ternary match (value and mask) equivalent to the criterion given
+ * when initialized. The returned byte sequences will have minimum size (i.e. rounded to the nearest byte) to
+ * contain the initialized field bit-width.
+ *
+ * @return a pair of byte sequences with value on the left and mask on the right
+ * @throws CriterionTranslatorException if the criterion cannot be translated
+ */
+ Pair<ImmutableByteSequence, ImmutableByteSequence> ternaryMatch() throws CriterionTranslatorException;
+
+ /**
+ * Returns a pair comprising a byte sequence and a prefix length representing a longest-prefix match equivalent to
+ * the criterion given when initialized. The returned byte sequence will have minimum size (i.e. rounded to the
+ * nearest byte) to contain the initialized field bit-width.
+ *
+ * @return a pair with the match value's byte sequence on the left, and prefix length on the right
+ * @throws CriterionTranslatorException if the criterion cannot be translated
+ */
+ Pair<ImmutableByteSequence, Integer> lpmMatch() throws CriterionTranslatorException;
+
+ /**
+ * Returns a byte sequence representing an exact match equivalent to the criterion given when initialized. The
+ * returned byte sequence will have minimum size (i.e. rounded to the nearest byte) to contain the initialized field
+ * bit-width.
+ *
+ * @return exact match value as a byte sequence
+ * @throws CriterionTranslatorException if the criterion cannot be translated
+ */
+ ImmutableByteSequence exactMatch() throws CriterionTranslatorException;
+
+ /**
+ * Signifies that the criterion cannot be translated.
+ */
+ class CriterionTranslatorException extends Exception {
+ CriterionTranslatorException(String message) {
+ super(message);
+ }
+ }
+}