Carmelo Cascone | 00a5996 | 2017-06-16 17:51:49 +0900 | [diff] [blame] | 1 | /* |
Brian O'Connor | a09fe5b | 2017-08-03 21:12:30 -0700 | [diff] [blame] | 2 | * Copyright 2017-present Open Networking Foundation |
Carmelo Cascone | 00a5996 | 2017-06-16 17:51:49 +0900 | [diff] [blame] | 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.net.pi.impl; |
| 18 | |
| 19 | |
| 20 | import org.apache.commons.lang3.tuple.Pair; |
| 21 | import org.onlab.util.ImmutableByteSequence; |
| 22 | import org.onosproject.net.flow.criteria.Criterion; |
| 23 | |
| 24 | import static org.onlab.util.ImmutableByteSequence.ByteSequenceTrimException; |
| 25 | |
| 26 | /** |
| 27 | * A translator of a criterion instance to different match types represented as primitive byte sequences. |
| 28 | */ |
| 29 | interface CriterionTranslator { |
| 30 | |
| 31 | /** |
| 32 | * Initialize this translator with the given criterion and field match bit-width. |
| 33 | * |
| 34 | * @param criterion criterion |
| 35 | * @param bitWidth field bit-width |
| 36 | * @throws ByteSequenceTrimException if the criterion cannot be trimmed to fit the field match bit-width |
| 37 | */ |
| 38 | void init(Criterion criterion, int bitWidth) throws ByteSequenceTrimException; |
| 39 | |
| 40 | /** |
| 41 | * Returns a pair of byte sequences representing a ternary match (value and mask) equivalent to the criterion given |
| 42 | * when initialized. The returned byte sequences will have minimum size (i.e. rounded to the nearest byte) to |
| 43 | * contain the initialized field bit-width. |
| 44 | * |
| 45 | * @return a pair of byte sequences with value on the left and mask on the right |
| 46 | * @throws CriterionTranslatorException if the criterion cannot be translated |
| 47 | */ |
| 48 | Pair<ImmutableByteSequence, ImmutableByteSequence> ternaryMatch() throws CriterionTranslatorException; |
| 49 | |
| 50 | /** |
| 51 | * Returns a pair comprising a byte sequence and a prefix length representing a longest-prefix match equivalent to |
| 52 | * the criterion given when initialized. The returned byte sequence will have minimum size (i.e. rounded to the |
| 53 | * nearest byte) to contain the initialized field bit-width. |
| 54 | * |
| 55 | * @return a pair with the match value's byte sequence on the left, and prefix length on the right |
| 56 | * @throws CriterionTranslatorException if the criterion cannot be translated |
| 57 | */ |
| 58 | Pair<ImmutableByteSequence, Integer> lpmMatch() throws CriterionTranslatorException; |
| 59 | |
| 60 | /** |
| 61 | * Returns a byte sequence representing an exact match equivalent to the criterion given when initialized. The |
| 62 | * returned byte sequence will have minimum size (i.e. rounded to the nearest byte) to contain the initialized field |
| 63 | * bit-width. |
| 64 | * |
| 65 | * @return exact match value as a byte sequence |
| 66 | * @throws CriterionTranslatorException if the criterion cannot be translated |
| 67 | */ |
| 68 | ImmutableByteSequence exactMatch() throws CriterionTranslatorException; |
| 69 | |
| 70 | /** |
| 71 | * Signifies that the criterion cannot be translated. |
| 72 | */ |
| 73 | class CriterionTranslatorException extends Exception { |
| 74 | CriterionTranslatorException(String message) { |
| 75 | super(message); |
| 76 | } |
| 77 | } |
| 78 | } |