| /* |
| * Copyright (C) 2016 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 android.net.metrics; |
| |
| import android.net.NetworkCapabilities; |
| import java.util.Arrays; |
| import com.android.internal.util.BitUtils; |
| |
| /** |
| * A DNS event recorded by NetdEventListenerService. |
| * {@hide} |
| */ |
| final public class DnsEvent { |
| |
| private static final int SIZE_LIMIT = 20000; |
| |
| // Network id of the network associated with the event, or 0 if unspecified. |
| public final int netId; |
| // Transports of the network associated with the event, as defined in NetworkCapabilities. |
| // It is the caller responsability to ensure the value of transports does not change between |
| // calls to addResult. |
| public final long transports; |
| // The number of DNS queries recorded. Queries are stored in the structure-of-array style where |
| // the eventTypes, returnCodes, and latenciesMs arrays have the same length and the i-th event |
| // is spread across the three array at position i. |
| public int eventCount; |
| // The types of DNS queries as defined in INetdEventListener. |
| public byte[] eventTypes; |
| // Current getaddrinfo codes go from 1 to EAI_MAX = 15. gethostbyname returns errno, but there |
| // are fewer than 255 errno values. So we store the result code in a byte as well. |
| public byte[] returnCodes; |
| // Latencies in milliseconds of queries, stored as ints. |
| public int[] latenciesMs; |
| |
| public DnsEvent(int netId, long transports, int initialCapacity) { |
| this.netId = netId; |
| this.transports = transports; |
| eventTypes = new byte[initialCapacity]; |
| returnCodes = new byte[initialCapacity]; |
| latenciesMs = new int[initialCapacity]; |
| } |
| |
| public void addResult(byte eventType, byte returnCode, int latencyMs) { |
| if (eventCount >= SIZE_LIMIT) { |
| // TODO: implement better rate limiting that does not biases metrics. |
| return; |
| } |
| if (eventCount == eventTypes.length) { |
| resize((int) (1.4 * eventCount)); |
| } |
| eventTypes[eventCount] = eventType; |
| returnCodes[eventCount] = returnCode; |
| latenciesMs[eventCount] = latencyMs; |
| eventCount++; |
| } |
| |
| public void resize(int newLength) { |
| eventTypes = Arrays.copyOf(eventTypes, newLength); |
| returnCodes = Arrays.copyOf(returnCodes, newLength); |
| latenciesMs = Arrays.copyOf(latenciesMs, newLength); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder builder = new StringBuilder("DnsEvent(").append(netId).append(", "); |
| for (int t : BitUtils.unpackBits(transports)) { |
| builder.append(NetworkCapabilities.transportNameOf(t)).append(", "); |
| } |
| return builder.append(eventCount).append(" events)").toString(); |
| } |
| } |