ConnectStats.java revision a2decca4f25b6d3adfd396cdc475807985783bab 
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 done in blocking mode. */
47    private int mConnectBlockingCount = 0;
48    /** Total count of successful connects with IPv6 socket address. */
49    private int mIpv6ConnectCount = 0;
50
51    public ConnectStats(TokenBucket tb, int maxLatencyRecords) {
52        mLatencyTb = tb;
53        mMaxLatencyRecords = maxLatencyRecords;
54    }
55
56    public ConnectStatistics toProto() {
57        ConnectStatistics stats = new ConnectStatistics();
58        stats.connectCount = mConnectCount;
59        stats.connectBlockingCount = mConnectBlockingCount;
60        stats.ipv6AddrCount = mIpv6ConnectCount;
61        stats.latenciesMs = mLatencies.toArray();
62        stats.errnosCounters = toPairArrays(mErrnos);
63        return stats;
64    }
65
66    public void addEvent(int errno, int latencyMs, String ipAddr) {
67        if (isSuccess(errno)) {
68            countConnect(errno, ipAddr);
69            countLatency(errno, latencyMs);
70        } else {
71            countError(errno);
72        }
73    }
74
75    private void countConnect(int errno, String ipAddr) {
76        mConnectCount++;
77        if (!isNonBlocking(errno)) {
78            mConnectBlockingCount++;
79        }
80        if (isIPv6(ipAddr)) {
81            mIpv6ConnectCount++;
82        }
83    }
84
85    private void countLatency(int errno, int ms) {
86        if (isNonBlocking(errno)) {
87            // Ignore connect() on non-blocking sockets
88            return;
89        }
90        if (!mLatencyTb.get()) {
91            // Rate limited
92            return;
93        }
94        if (mLatencies.size() >= mMaxLatencyRecords) {
95            // Hard limit the total number of latency measurements.
96            return;
97        }
98        mLatencies.add(ms);
99    }
100
101    private void countError(int errno) {
102        final int newcount = mErrnos.get(errno, 0) + 1;
103        mErrnos.put(errno, newcount);
104    }
105
106    private static boolean isSuccess(int errno) {
107        return (errno == 0) || isNonBlocking(errno);
108    }
109
110    private static boolean isNonBlocking(int errno) {
111        // On non-blocking TCP sockets, connect() immediately returns EINPROGRESS.
112        // On non-blocking TCP sockets that are connecting, connect() immediately returns EALREADY.
113        return (errno == EINPROGRESS) || (errno == EALREADY);
114    }
115
116    private static boolean isIPv6(String ipAddr) {
117        return ipAddr.contains(":");
118    }
119
120    private static Pair[] toPairArrays(SparseIntArray counts) {
121        final int s = counts.size();
122        Pair[] pairs = new Pair[s];
123        for (int i = 0; i < s; i++) {
124            Pair p = new Pair();
125            p.key = counts.keyAt(i);
126            p.value = counts.valueAt(i);
127            pairs[i] = p;
128        }
129        return pairs;
130    }
131
132    @Override
133    public String toString() {
134        StringBuilder builder = new StringBuilder("ConnectStats(")
135                .append(String.format("%d success, ", mConnectCount))
136                .append(String.format("%d blocking, ", mConnectBlockingCount))
137                .append(String.format("%d IPv6 dst", mIpv6ConnectCount));
138        for (int i = 0; i < mErrnos.size(); i++) {
139            String errno = OsConstants.errnoName(mErrnos.keyAt(i));
140            int count = mErrnos.valueAt(i);
141            builder.append(String.format(", %s: %d", errno, count));
142        }
143        return builder.append(")").toString();
144    }
145}
146