1/*
2 * Copyright (C) 2019 Igalia S.L.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "PrefetchCache.h"
28
29#include <WebCore/HTTPHeaderNames.h>
30
31namespace WebKit {
32
33PrefetchCache::Entry::Entry(WebCore::ResourceResponse&& response, RefPtr<WebCore::SharedBuffer>&& buffer)
34 : response(WTFMove(response)), buffer(WTFMove(buffer))
35{
36}
37
38PrefetchCache::Entry::Entry(WebCore::ResourceResponse&& redirectResponse, WebCore::ResourceRequest&& redirectRequest)
39 : response(WTFMove(redirectResponse)), redirectRequest(WTFMove(redirectRequest))
40{
41}
42
43PrefetchCache::PrefetchCache()
44 : m_expirationTimer(*this, &PrefetchCache::clearExpiredEntries)
45{
46}
47
48PrefetchCache::~PrefetchCache()
49{
50}
51
52void PrefetchCache::clear()
53{
54 m_expirationTimer.stop();
55 m_sessionExpirationList.clear();
56 if (m_sessionPrefetches)
57 m_sessionPrefetches->clear();
58}
59
60std::unique_ptr<PrefetchCache::Entry> PrefetchCache::take(const URL& url)
61{
62 auto* resources = m_sessionPrefetches.get();
63 if (!resources)
64 return nullptr;
65 m_sessionExpirationList.removeAllMatching([&url] (const auto& tuple) {
66 return std::get<0>(tuple) == url;
67 });
68 return resources->take(url);
69}
70
71static const Seconds expirationTimeout { 5_s };
72
73void PrefetchCache::store(const URL& requestUrl, WebCore::ResourceResponse&& response, RefPtr<WebCore::SharedBuffer>&& buffer)
74{
75 if (!m_sessionPrefetches)
76 m_sessionPrefetches = std::make_unique<PrefetchEntriesMap>();
77 auto addResult = m_sessionPrefetches->add(requestUrl, std::make_unique<PrefetchCache::Entry>(WTFMove(response), WTFMove(buffer)));
78 // Limit prefetches for same url to 1.
79 if (!addResult.isNewEntry)
80 return;
81 m_sessionExpirationList.append(std::make_tuple(requestUrl, WallTime::now()));
82 if (!m_expirationTimer.isActive())
83 m_expirationTimer.startOneShot(expirationTimeout);
84}
85
86void PrefetchCache::storeRedirect(const URL& requestUrl, WebCore::ResourceResponse&& redirectResponse, WebCore::ResourceRequest&& redirectRequest)
87{
88 if (!m_sessionPrefetches)
89 m_sessionPrefetches = std::make_unique<PrefetchEntriesMap>();
90 redirectRequest.clearPurpose();
91 m_sessionPrefetches->set(requestUrl, std::make_unique<PrefetchCache::Entry>(WTFMove(redirectResponse), WTFMove(redirectRequest)));
92 m_sessionExpirationList.append(std::make_tuple(requestUrl, WallTime::now()));
93 if (!m_expirationTimer.isActive())
94 m_expirationTimer.startOneShot(expirationTimeout);
95}
96
97void PrefetchCache::clearExpiredEntries()
98{
99 URL requestUrl;
100 WallTime timestamp;
101 auto timeout = WallTime::now();
102 while (!m_sessionExpirationList.isEmpty()) {
103 std::tie(requestUrl, timestamp) = m_sessionExpirationList.first();
104 auto* resources = m_sessionPrefetches.get();
105 ASSERT(resources);
106 ASSERT(resources->contains(requestUrl));
107 auto elapsed = timeout - timestamp;
108 if (elapsed > expirationTimeout) {
109 resources->remove(requestUrl);
110 m_sessionExpirationList.removeFirst();
111 } else {
112 m_expirationTimer.startOneShot(expirationTimeout - elapsed);
113 break;
114 }
115 }
116}
117
118}
119