ConnectStats.java revision 0d4a398b7846f26e4452180915ecb5a9d4566148 
1/*
2 * Copyright (C) 2016 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
17package android.net.metrics;
18
19import android.system.OsConstants;
20import android.util.IntArray;
21import android.util.SparseIntArray;
22import com.android.internal.util.TokenBucket;
23import com.android.server.connectivity.metrics.nano.IpConnectivityLogClass.ConnectStatistics;
24import com.android.server.connectivity.metrics.nano.IpConnectivityLogClass.Pair;
25
26/**
27 * A class that aggregates connect() statistics and helps build
28 * IpConnectivityLogClass.ConnectStatistics instances.
29 *
30 * {@hide}
31 */
32public class ConnectStats {
33    private final static int EALREADY     = OsConstants.EALREADY;
34    private final static int EINPROGRESS  = OsConstants.EINPROGRESS;
35
36    /** How many events resulted in a given errno. */
37    private final SparseIntArray mErrnos = new SparseIntArray();
38    /** Latencies of blocking connects. TODO: add non-blocking connects latencies. */
39    private final IntArray mLatencies = new IntArray();
40    /** TokenBucket for rate limiting latency recording. */
41    private final TokenBucket mLatencyTb;
42    /** Maximum number of latency values recorded. */
43    private final int mMaxLatencyRecords;
44    /** Total count of successful connects. */
45    private int mConnectCount = 0;
46    /** Total count of successful connects with IPv6 socket address. */
47    private int mIpv6ConnectCount = 0;
48
49    public ConnectStats(TokenBucket tb, int maxLatencyRecords) {
50        mLatencyTb = tb;
51        mMaxLatencyRecords = maxLatencyRecords;
52    }
53
54    public ConnectStatistics toProto() {
55        ConnectStatistics stats = new ConnectStatistics();
56        stats.connectCount = mConnectCount;
57        stats.ipv6AddrCount = mIpv6ConnectCount;
58        stats.latenciesMs = mLatencies.toArray();
59        stats.errnosCounters = toPairArrays(mErrnos);
60        return stats;
61    }
62
63    public void addEvent(int errno, int latencyMs, String ipAddr) {
64        if (isSuccess(errno)) {
65            countConnect(ipAddr);
66            countLatency(errno, latencyMs);
67        } else {
68            countError(errno);
69        }
70    }
71
72    private void countConnect(String ipAddr) {
73        mConnectCount++;
74        if (isIPv6(ipAddr)) mIpv6ConnectCount++;
75    }
76
77    private void countLatency(int errno, int ms) {
78        if (isNonBlocking(errno)) {
79            // Ignore connect() on non-blocking sockets
80            return;
81        }
82        if (!mLatencyTb.get()) {
83            // Rate limited
84            return;
85        }
86        if (mLatencies.size() >= mMaxLatencyRecords) {
87            // Hard limit the total number of latency measurements.
88            return;
89        }
90        mLatencies.add(ms);
91    }
92
93    private void countError(int errno) {
94        final int newcount = mErrnos.get(errno, 0) + 1;
95        mErrnos.put(errno, newcount);
96    }
97
98    private static boolean isSuccess(int errno) {
99        return (errno == 0) || isNonBlocking(errno);
100    }
101
102    private static boolean isNonBlocking(int errno) {
103        // On non-blocking TCP sockets, connect() immediately returns EINPROGRESS.
104        // On non-blocking TCP sockets that are connecting, connect() immediately returns EALREADY.
105        return (errno == EINPROGRESS) || (errno == EALREADY);
106    }
107
108    private static boolean isIPv6(String ipAddr) {
109        return ipAddr.contains(":");
110    }
111
112    private static Pair[] toPairArrays(SparseIntArray counts) {
113        final int s = counts.size();
114        Pair[] pairs = new Pair[s];
115        for (int i = 0; i < s; i++) {
116            Pair p = new Pair();
117            p.key = counts.keyAt(i);
118            p.value = counts.valueAt(i);
119            pairs[i] = p;
120        }
121        return pairs;
122    }
123}
124