ConnectStats.java revision 5eb9053c4e8c788b83cfcfd7bfd39f628dd4ca45 
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.net.NetworkCapabilities;
20import android.system.OsConstants;
21import android.util.IntArray;
22import android.util.SparseIntArray;
23import com.android.internal.util.BitUtils;
24import com.android.internal.util.TokenBucket;
25
26/**
27 * A class that aggregates connect() statistics.
28 * {@hide}
29 */
30public class ConnectStats {
31    private final static int EALREADY     = OsConstants.EALREADY;
32    private final static int EINPROGRESS  = OsConstants.EINPROGRESS;
33
34    /** Network id of the network associated with the event, or 0 if unspecified. */
35    public final int netId;
36    /** Transports of the network associated with the event, as defined in NetworkCapabilities. */
37    public final long transports;
38    /** How many events resulted in a given errno. */
39    public final SparseIntArray errnos = new SparseIntArray();
40    /** Latencies of successful blocking connects. TODO: add non-blocking connects latencies. */
41    public final IntArray latencies = new IntArray();
42    /** TokenBucket for rate limiting latency recording. */
43    public final TokenBucket mLatencyTb;
44    /** Maximum number of latency values recorded. */
45    public final int mMaxLatencyRecords;
46    /** Total count of successful connects. */
47    public int connectCount = 0;
48    /** Total count of successful connects done in blocking mode. */
49    public int connectBlockingCount = 0;
50    /** Total count of successful connects with IPv6 socket address. */
51    public int ipv6ConnectCount = 0;
52
53    public ConnectStats(int netId, long transports, TokenBucket tb, int maxLatencyRecords) {
54        this.netId = netId;
55        this.transports = transports;
56        mLatencyTb = tb;
57        mMaxLatencyRecords = maxLatencyRecords;
58    }
59
60    public void addEvent(int errno, int latencyMs, String ipAddr) {
61        if (isSuccess(errno)) {
62            countConnect(errno, ipAddr);
63            countLatency(errno, latencyMs);
64        } else {
65            countError(errno);
66        }
67    }
68
69    private void countConnect(int errno, String ipAddr) {
70        connectCount++;
71        if (!isNonBlocking(errno)) {
72            connectBlockingCount++;
73        }
74        if (isIPv6(ipAddr)) {
75            ipv6ConnectCount++;
76        }
77    }
78
79    private void countLatency(int errno, int ms) {
80        if (isNonBlocking(errno)) {
81            // Ignore connect() on non-blocking sockets
82            return;
83        }
84        if (!mLatencyTb.get()) {
85            // Rate limited
86            return;
87        }
88        if (latencies.size() >= mMaxLatencyRecords) {
89            // Hard limit the total number of latency measurements.
90            return;
91        }
92        latencies.add(ms);
93    }
94
95    private void countError(int errno) {
96        final int newcount = errnos.get(errno, 0) + 1;
97        errnos.put(errno, newcount);
98    }
99
100    private static boolean isSuccess(int errno) {
101        return (errno == 0) || isNonBlocking(errno);
102    }
103
104    private static boolean isNonBlocking(int errno) {
105        // On non-blocking TCP sockets, connect() immediately returns EINPROGRESS.
106        // On non-blocking TCP sockets that are connecting, connect() immediately returns EALREADY.
107        return (errno == EINPROGRESS) || (errno == EALREADY);
108    }
109
110    private static boolean isIPv6(String ipAddr) {
111        return ipAddr.contains(":");
112    }
113
114    @Override
115    public String toString() {
116        StringBuilder builder = new StringBuilder("ConnectStats(").append(netId).append(", ");
117        for (int t : BitUtils.unpackBits(transports)) {
118            builder.append(NetworkCapabilities.transportNameOf(t)).append(", ");
119        }
120        builder.append(String.format("%d success, ", connectCount));
121        builder.append(String.format("%d blocking, ", connectBlockingCount));
122        builder.append(String.format("%d IPv6 dst", ipv6ConnectCount));
123        for (int i = 0; i < errnos.size(); i++) {
124            String errno = OsConstants.errnoName(errnos.keyAt(i));
125            int count = errnos.valueAt(i);
126            builder.append(String.format(", %s: %d", errno, count));
127        }
128        return builder.append(")").toString();
129    }
130}
131