File: DNSCache.cpp

package info (click to toggle)
webkit2gtk 2.42.2-1~deb12u1
  • links: PTS, VCS
  • area: main
  • in suites:
  • size: 362,452 kB
  • sloc: cpp: 2,881,971; javascript: 282,447; ansic: 134,088; python: 43,789; ruby: 18,308; perl: 15,872; asm: 14,389; xml: 4,395; yacc: 2,350; sh: 2,074; java: 1,734; lex: 1,323; makefile: 288; pascal: 60
file content (140 lines) | stat: -rw-r--r-- 4,265 bytes parent folder | download | duplicates (8)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/*
 * Copyright (C) 2019 Igalia S.L.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "DNSCache.h"

#include <wtf/glib/RunLoopSourcePriority.h>

namespace WebKit {

static const Seconds expireInterval = 60_s;
static const unsigned maxCacheSize = 400;

DNSCache::DNSCache()
    : m_expiredTimer(RunLoop::main(), this, &DNSCache::removeExpiredResponsesFired)
{
    m_expiredTimer.setPriority(RunLoopSourcePriority::ReleaseUnusedResourcesTimer);
}

DNSCache::DNSCacheMap& DNSCache::mapForType(Type type)
{
    switch (type) {
    case Type::Default:
        return m_dnsMap;
    case Type::IPv4Only:
#if GLIB_CHECK_VERSION(2, 59, 0)
        return m_ipv4Map;
#else
        return m_dnsMap;
#endif
    case Type::IPv6Only:
#if GLIB_CHECK_VERSION(2, 59, 0)
        return m_ipv6Map;
#else
        return m_dnsMap;
#endif
    }

    RELEASE_ASSERT_NOT_REACHED();
    return m_dnsMap;
}

std::optional<Vector<GRefPtr<GInetAddress>>> DNSCache::lookup(const CString& host, Type type)
{
    Locker locker { m_lock };
    auto& map = mapForType(type);
    auto it = map.find(host);
    if (it == map.end())
        return std::nullopt;

    auto& response = it->value;
    if (response.expirationTime <= MonotonicTime::now()) {
        map.remove(it);
        return std::nullopt;
    }

    return response.addressList;
}

void DNSCache::update(const CString& host, Vector<GRefPtr<GInetAddress>>&& addressList, Type type)
{
    Locker locker { m_lock };
    auto& map = mapForType(type);
    CachedResponse response = { WTFMove(addressList), MonotonicTime::now() + expireInterval };
    auto addResult = map.set(host, WTFMove(response));
    if (addResult.isNewEntry)
        pruneResponsesInMap(map);
    m_expiredTimer.startOneShot(expireInterval);
}

void DNSCache::removeExpiredResponsesInMap(DNSCacheMap& map)
{
    map.removeIf([now = MonotonicTime::now()](auto& entry) {
        return entry.value.expirationTime <= now;
    });
}

void DNSCache::pruneResponsesInMap(DNSCacheMap& map)
{
    if (map.size() <= maxCacheSize)
        return;

    // First try to remove expired responses.
    removeExpiredResponsesInMap(map);
    if (map.size() <= maxCacheSize)
        return;

    Vector<CString> keys = copyToVector(map.keys());
    std::sort(keys.begin(), keys.end(), [&map](const CString& a, const CString& b) {
        return map.get(a).expirationTime < map.get(b).expirationTime;
    });

    unsigned responsesToRemoveCount = keys.size() - maxCacheSize;
    for (unsigned i = 0; i < responsesToRemoveCount; ++i)
        map.remove(keys[i]);
}

void DNSCache::removeExpiredResponsesFired()
{
    Locker locker { m_lock };
    removeExpiredResponsesInMap(m_dnsMap);
#if GLIB_CHECK_VERSION(2, 59, 0)
    removeExpiredResponsesInMap(m_ipv4Map);
    removeExpiredResponsesInMap(m_ipv6Map);
#endif
}

void DNSCache::clear()
{
    Locker locker { m_lock };
    m_dnsMap.clear();
#if GLIB_CHECK_VERSION(2, 59, 0)
    m_ipv4Map.clear();
    m_ipv6Map.clear();
#endif
}

} // namespace WebKit