| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * 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 com.android.tradefed.util; |
| |
| import com.android.tradefed.log.LogUtil.CLog; |
| |
| import com.google.protobuf.Descriptors.FieldDescriptor; |
| import com.google.protobuf.Message; |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.stream.Collectors; |
| |
| /** Utility methods for dealing with protobuf messages type-agnostically. */ |
| public class ProtoUtil { |
| |
| /** |
| * Get values of a nested field reference, i.e. field_1.field_2.field_3, from a proto message as |
| * a list of strings. Returns an empty list when a field cannot be found. |
| * |
| * <p>If the field reference contains repeated fields, each instance is expanded, resulting in a |
| * list of strings. |
| * |
| * @param message The protobuf {@link Message} or object to be parsed. |
| * @param references A list of field references starting at the root of the message. e.g. if we |
| * want to read {@code field_2} under the value of {@code field_1} in {@code |
| * messageOrObject} the list would be {@code field1}, {@code field2}. |
| * @return A list of all the fields values referred to by the reference. If {@code references} |
| * is empty, returns {@code message.toString()} as a list. If {@code references} is invalid, |
| * returns an empty list. |
| */ |
| public static List<String> getNestedFieldFromMessageAsStrings( |
| Message message, List<String> references) { |
| return getNestedFieldFromMessageAsStringsHelper(message, references); |
| } |
| |
| /** |
| * A helper method to {@code getNestedFieldFromMessageAsStrings} where the "message" can be an |
| * object in case we reach a primitive value field during recursive parsing. |
| */ |
| private static List<String> getNestedFieldFromMessageAsStringsHelper( |
| Object messageOrObject, List<String> references) { |
| if (references.isEmpty()) { |
| return Arrays.asList(String.valueOf(messageOrObject)); |
| } |
| if (!(messageOrObject instanceof Message)) { |
| CLog.e( |
| "Attempting to read field %s from object of type %s, " |
| + "which is not a proto message.", |
| references.get(0), messageOrObject.getClass()); |
| return new ArrayList<String>(); |
| } |
| Message message = (Message) messageOrObject; |
| String reference = references.get(0); |
| FieldDescriptor fieldDescriptor = message.getDescriptorForType().findFieldByName(reference); |
| if (fieldDescriptor == null) { |
| CLog.e("Could not find field %s in message %s.", reference, message); |
| return new ArrayList<String>(); |
| } |
| Object fieldValue = message.getField(fieldDescriptor); |
| if (fieldValue instanceof List) { |
| return ((List<? extends Object>) fieldValue) |
| .stream() |
| .flatMap( |
| v -> |
| getNestedFieldFromMessageAsStringsHelper( |
| v, references.subList(1, references.size())) |
| .stream()) |
| .collect(Collectors.toList()); |
| } |
| return getNestedFieldFromMessageAsStringsHelper( |
| fieldValue, references.subList(1, references.size())); |
| } |
| } |