| /* |
| * Copyright 2017-present Open Networking Foundation |
| * |
| * 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.runtime; |
| |
| import org.onlab.util.Identifier; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| /** |
| * Identifier of a packet's header field. |
| */ |
| public final class PiHeaderFieldId extends Identifier<String> { |
| |
| // FIXME: this abstraction is brittle and we should drop any string-composition logic. |
| // e.g. in P4_14 there is no scope for match fields. |
| // In light of ONOS-7066, the best solution seems to have IDs defined as arbitrary |
| // strings equal to the entity names defined in the P4Info. |
| private final String headerName; |
| private final String fieldName; |
| private final int index; |
| |
| private PiHeaderFieldId(String headerName, String fieldName, int index) { |
| super(headerName + |
| (index > 0 ? "[" + String.valueOf(index) + "]" : "") + |
| "." + fieldName); |
| this.headerName = headerName; |
| this.fieldName = fieldName; |
| this.index = index; |
| } |
| |
| /** |
| * Returns an header field identifier for the given header name, field name and index. |
| * <p> |
| * Index represents the position of this header in the packet w.r.t. to other headers of the |
| * same type. Index 0 points to the first instance of the header, 1 the second one, etc. Helpful |
| * when dealing with stacked headers, e.g. to match on the second MPLS label. |
| * |
| * @param headerName header name |
| * @param fieldName field name |
| * @param index index |
| * @return header field identifier |
| */ |
| public static PiHeaderFieldId of(String headerName, String fieldName, int index) { |
| checkNotNull(headerName); |
| checkNotNull(fieldName); |
| checkArgument(!headerName.isEmpty(), "Header name can't be empty"); |
| checkArgument(!fieldName.isEmpty(), "Field name can't be empty"); |
| checkArgument(index >= 0, "Index must be a positive integer"); |
| return new PiHeaderFieldId(headerName, fieldName, index); |
| } |
| |
| /** |
| * Returns an header field identifier for the given header name and field name. |
| * Index is set to default value 0. |
| * |
| * @param headerName header name |
| * @param fieldName field name |
| * @return header field identifier |
| */ |
| public static PiHeaderFieldId of(String headerName, String fieldName) { |
| return of(headerName, fieldName, 0); |
| } |
| |
| /** |
| * Returns the name of the header. |
| * |
| * @return a string value |
| */ |
| public String headerName() { |
| return headerName; |
| } |
| |
| /** |
| * Returns the name of the field. |
| * |
| * @return a string value |
| */ |
| public String fieldName() { |
| return fieldName; |
| } |
| |
| /** |
| * Returns the index of this header. |
| * |
| * @return an integer value. |
| */ |
| public int index() { |
| return index; |
| } |
| } |