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
|
// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/platform/media/cache_util.h"
#include <stddef.h>
#include <string>
#include <string_view>
#include "base/containers/contains.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/time/time.h"
#include "net/http/http_util.h"
#include "net/http/http_version.h"
#include "third_party/blink/public/platform/web_string.h"
#include "third_party/blink/public/platform/web_url_response.h"
namespace blink {
using ::base::Time;
using ::net::HttpVersion;
enum { kHttpOK = 200, kHttpPartialContent = 206 };
uint32_t GetReasonsForUncacheability(const WebURLResponse& response) {
uint32_t reasons = 0;
const int code = response.HttpStatusCode();
const int version = response.HttpVersion();
const HttpVersion http_version =
version == WebURLResponse::kHTTPVersion_2_0 ? HttpVersion(2, 0)
: version == WebURLResponse::kHTTPVersion_1_1 ? HttpVersion(1, 1)
: version == WebURLResponse::kHTTPVersion_1_0 ? HttpVersion(1, 0)
: version == WebURLResponse::kHTTPVersion_0_9 ? HttpVersion(0, 9)
: HttpVersion();
if (code != kHttpOK && code != kHttpPartialContent)
reasons |= kNoData;
if (http_version < HttpVersion(1, 1) && code == kHttpPartialContent)
reasons |= kPre11PartialResponse;
if (code == kHttpPartialContent &&
!net::HttpUtil::HasStrongValidators(
http_version, response.HttpHeaderField("etag").Utf8(),
response.HttpHeaderField("Last-Modified").Utf8(),
response.HttpHeaderField("Date").Utf8())) {
reasons |= kNoStrongValidatorOnPartialResponse;
}
std::string cache_control_header =
base::ToLowerASCII(response.HttpHeaderField("cache-control").Utf8());
if (base::Contains(cache_control_header, "no-cache")) {
reasons |= kNoCache;
}
if (base::Contains(cache_control_header, "no-store")) {
reasons |= kNoStore;
}
if (base::Contains(cache_control_header, "must-revalidate")) {
reasons |= kHasMustRevalidate;
}
const base::TimeDelta kMinimumAgeForUsefulness =
base::Seconds(3600); // Arbitrary value.
constexpr std::string_view kMaxAgePrefix = "max-age=";
if (cache_control_header.starts_with(kMaxAgePrefix)) {
int64_t max_age_seconds;
base::StringToInt64(
std::string_view(cache_control_header).substr(kMaxAgePrefix.size()),
&max_age_seconds);
if (base::Seconds(max_age_seconds) < kMinimumAgeForUsefulness) {
reasons |= kShortMaxAge;
}
}
Time date;
Time expires;
if (Time::FromString(response.HttpHeaderField("Date").Utf8().data(), &date) &&
Time::FromString(response.HttpHeaderField("Expires").Utf8().data(),
&expires) &&
date > Time() && expires > Time() &&
(expires - date) < kMinimumAgeForUsefulness) {
reasons |= kExpiresTooSoon;
}
return reasons;
}
base::TimeDelta GetCacheValidUntil(const WebURLResponse& response) {
std::string cache_control_header =
base::ToLowerASCII(response.HttpHeaderField("cache-control").Utf8());
if (base::Contains(cache_control_header, "no-cache") ||
base::Contains(cache_control_header, "must-revalidate")) {
return base::TimeDelta();
}
// Max cache timeout ~= 1 month.
base::TimeDelta ret = base::Days(30);
constexpr std::string_view kMaxAgePrefix = "max-age=";
if (cache_control_header.starts_with(kMaxAgePrefix)) {
int64_t max_age_seconds;
base::StringToInt64(
std::string_view(cache_control_header).substr(kMaxAgePrefix.size()),
&max_age_seconds);
ret = std::min(ret, base::Seconds(max_age_seconds));
} else {
// Note that |date| may be smaller than |expires|, which means we'll
// return a timetick some time in the past.
Time date;
Time expires;
if (Time::FromString(response.HttpHeaderField("Date").Utf8().data(),
&date) &&
Time::FromString(response.HttpHeaderField("Expires").Utf8().data(),
&expires) &&
date > Time() && expires > Time()) {
ret = std::min(ret, expires - date);
}
}
return ret;
}
} // namespace blink
|
