1 /* 2 * Copyright (C) 2024 The Android Open Source Project 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 package com.android.adservices.shared.flags; 17 18 import java.util.Objects; 19 20 /** 21 * Abstraction for how {@code Flags} are stored and retrieved. 22 * 23 * <p>By default all methods uses {@link #getFlag(String)}, but implementations can override them to 24 * call backend-specific methods (like those provided by {@code DeviceConfig}. 25 */ 26 public interface FlagsBackend { 27 28 /** Gets the canonical value of a flag, or {@code null} when not present. */ getFlag(String name)29 String getFlag(String name); 30 31 /** Gets the value of a {@code boolean} flag, or {@code defaultValue} when not present. */ getFlag(String name, boolean defaultValue)32 default boolean getFlag(String name, boolean defaultValue) { 33 String value = getFlagChecked(name); 34 return value == null ? defaultValue : Boolean.parseBoolean(value); 35 } 36 37 /** Gets the value of a {@code String} flag, or {@code defaultValue} when not present. */ getFlag(String name, String defaultValue)38 default String getFlag(String name, String defaultValue) { 39 String value = getFlagChecked(name); 40 return value == null ? defaultValue : value; 41 } 42 43 /** Gets the value of a {@code int} flag, or {@code defaultValue} when not present. */ getFlag(String name, int defaultValue)44 default int getFlag(String name, int defaultValue) { 45 String value = getFlagChecked(name); 46 return value == null ? defaultValue : Integer.parseInt(value); 47 } 48 49 /** Gets the value of a {@code long} flag, or {@code defaultValue} when not present. */ getFlag(String name, long defaultValue)50 default long getFlag(String name, long defaultValue) { 51 String value = getFlagChecked(name); 52 return value == null ? defaultValue : Long.parseLong(value); 53 } 54 55 /** Gets the value of a {@code float} flag, or {@code defaultValue} when not present. */ getFlag(String name, float defaultValue)56 default float getFlag(String name, float defaultValue) { 57 String value = getFlagChecked(name); 58 return value == null ? defaultValue : Float.parseFloat(value); 59 } 60 getFlagChecked(String name)61 private String getFlagChecked(String name) { 62 Objects.requireNonNull(name, "name cannot be null"); 63 return getFlag(name); 64 } 65 } 66