1   
//
1   
//
2   
// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
2   
// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
3   
//
3   
//
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6   
//
6   
//
7   
// Official repository: https://github.com/boostorg/url
7   
// Official repository: https://github.com/boostorg/url
8   
//
8   
//
9  
9  
10  
10  
11   
#include <boost/url/detail/config.hpp>
11   
#include <boost/url/detail/config.hpp>
12   
#include <boost/url/grammar/ci_string.hpp>
12   
#include <boost/url/grammar/ci_string.hpp>
13  
13  
14   
namespace boost {
14   
namespace boost {
15   
namespace urls {
15   
namespace urls {
16   
namespace grammar {
16   
namespace grammar {
17  
17  
18   
namespace detail {
18   
namespace detail {
19  
19  
20   
//------------------------------------------------
20   
//------------------------------------------------
21  
21  
22   
// https://lemire.me/blog/2020/04/30/for-case-insensitive-string-comparisons-avoid-char-by-char-functions/
22   
// https://lemire.me/blog/2020/04/30/for-case-insensitive-string-comparisons-avoid-char-by-char-functions/
23   
// https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/blob/master/2020/04/30/tolower.cpp
23   
// https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/blob/master/2020/04/30/tolower.cpp
24  
24  
25   
bool
25   
bool
26   
ci_is_equal(
26   
ci_is_equal(
27   
    core::string_view s0,
27   
    core::string_view s0,
28   
    core::string_view s1) noexcept
28   
    core::string_view s1) noexcept
29   
{
29   
{
30   
    auto n = s0.size();
30   
    auto n = s0.size();
31   
    auto p1 = s0.data();
31   
    auto p1 = s0.data();
32   
    auto p2 = s1.data();
32   
    auto p2 = s1.data();
33   
    char a, b;
33   
    char a, b;
34   
    // fast loop
34   
    // fast loop
35   
    while(n--)
35   
    while(n--)
36   
    {
36   
    {
37   
        a = *p1++;
37   
        a = *p1++;
38   
        b = *p2++;
38   
        b = *p2++;
39   
        if(a != b)
39   
        if(a != b)
40   
            goto slow;
40   
            goto slow;
41   
    }
41   
    }
42   
    return true;
42   
    return true;
43   
    do
43   
    do
44   
    {
44   
    {
45   
        a = *p1++;
45   
        a = *p1++;
46   
        b = *p2++;
46   
        b = *p2++;
47   
    slow:
47   
    slow:
48   
        if( to_lower(a) !=
48   
        if( to_lower(a) !=
49   
            to_lower(b))
49   
            to_lower(b))
50   
            return false;
50   
            return false;
51   
    }
51   
    }
52   
    while(n--);
52   
    while(n--);
53   
    return true;
53   
    return true;
54   
}
54   
}
55  
55  
56   
//------------------------------------------------
56   
//------------------------------------------------
57  
57  
58   
bool
58   
bool
59   
ci_is_less(
59   
ci_is_less(
60   
    core::string_view s0,
60   
    core::string_view s0,
61   
    core::string_view s1) noexcept
61   
    core::string_view s1) noexcept
62   
{
62   
{
63   
    auto p1 = s0.data();
63   
    auto p1 = s0.data();
64   
    auto p2 = s1.data();
64   
    auto p2 = s1.data();
65   
    auto n = s0.size() < s1.size()
65   
    auto n = s0.size() < s1.size()
66   
        ? s0.size() : s1.size();
66   
        ? s0.size() : s1.size();
67   
    while(n--)
67   
    while(n--)
68   
    {
68   
    {
69   
        auto c1 = to_lower(*p1++);
69   
        auto c1 = to_lower(*p1++);
70   
        auto c2 = to_lower(*p2++);
70   
        auto c2 = to_lower(*p2++);
71   
        if(c1 != c2)
71   
        if(c1 != c2)
72   
            return c1 < c2;
72   
            return c1 < c2;
73   
    }
73   
    }
74   
    return s0.size() < s1.size();
74   
    return s0.size() < s1.size();
75   
}
75   
}
76  
76  
77   
} // detail
77   
} // detail
78  
78  
79   
//------------------------------------------------
79   
//------------------------------------------------
80  
80  
81   
int
81   
int
82   
ci_compare(
82   
ci_compare(
83   
    core::string_view s0,
83   
    core::string_view s0,
84   
    core::string_view s1) noexcept
84   
    core::string_view s1) noexcept
85   
{
85   
{
86   
    int bias;
86   
    int bias;
87   
    std::size_t n;
87   
    std::size_t n;
88   
    if( s0.size() <
88   
    if( s0.size() <
89   
        s1.size())
89   
        s1.size())
90   
    {
90   
    {
91   
        bias = -1;
91   
        bias = -1;
92   
        n = s0.size();
92   
        n = s0.size();
93   
    }
93   
    }
94   
    else
94   
    else
95   
    {
95   
    {
96   
        if( s0.size() >
96   
        if( s0.size() >
97   
            s1.size())
97   
            s1.size())
98   
            bias = 1;
98   
            bias = 1;
99   
        else
99   
        else
100   
            bias = 0;
100   
            bias = 0;
101   
        n = s1.size();
101   
        n = s1.size();
102   
    }
102   
    }
103   
    auto it0 = s0.data();
103   
    auto it0 = s0.data();
104   
    auto it1 = s1.data();
104   
    auto it1 = s1.data();
105   
    while(n--)
105   
    while(n--)
106   
    {
106   
    {
107   
        auto c0 =
107   
        auto c0 =
108   
            to_lower(*it0++);
108   
            to_lower(*it0++);
109   
        auto c1 =
109   
        auto c1 =
110   
            to_lower(*it1++);
110   
            to_lower(*it1++);
111   
        if(c0 == c1)
111   
        if(c0 == c1)
112   
            continue;
112   
            continue;
113   
        if(c0 < c1)
113   
        if(c0 < c1)
114   
            return -1;
114   
            return -1;
115   
        return 1;
115   
        return 1;
116   
    }
116   
    }
117   
    return bias;
117   
    return bias;
118   
}
118   
}
119  
119  
120   
//------------------------------------------------
120   
//------------------------------------------------
121  
121  
122   
std::size_t
122   
std::size_t
123   
ci_digest(
123   
ci_digest(
124   
    core::string_view s) noexcept
124   
    core::string_view s) noexcept
125   
{
125   
{
126   
    // Only 4 and 8 byte sizes are supported
126   
    // Only 4 and 8 byte sizes are supported
127   
    static_assert(
127   
    static_assert(
128   
        sizeof(std::size_t) == 4 ||
128   
        sizeof(std::size_t) == 4 ||
129   
        sizeof(std::size_t) == 8, "");
129   
        sizeof(std::size_t) == 8, "");
130   
    constexpr std::size_t prime = (
130   
    constexpr std::size_t prime = (
131   
        sizeof(std::size_t) == 8) ?
131   
        sizeof(std::size_t) == 8) ?
132   
            0x100000001B3ULL :
132   
            0x100000001B3ULL :
133   
            0x01000193UL;
133   
            0x01000193UL;
134   
    constexpr std::size_t hash0 = (
134   
    constexpr std::size_t hash0 = (
135   
        sizeof(std::size_t) == 8) ?
135   
        sizeof(std::size_t) == 8) ?
136   
            0xcbf29ce484222325ULL :
136   
            0xcbf29ce484222325ULL :
137   
            0x811C9DC5UL;
137   
            0x811C9DC5UL;
138   
    auto hash = hash0;
138   
    auto hash = hash0;
139   
    auto p = s.data();
139   
    auto p = s.data();
140   
    auto n = s.size();
140   
    auto n = s.size();
141   
    for(;n--;++p)
141   
    for(;n--;++p)
142   
    {
142   
    {
143   
        // VFALCO NOTE Consider using a lossy
143   
        // VFALCO NOTE Consider using a lossy
144   
        // to_lower which works 4 or 8 chars at a time.
144   
        // to_lower which works 4 or 8 chars at a time.
145   
        hash = (to_lower(*p) ^ hash) * prime;
145   
        hash = (to_lower(*p) ^ hash) * prime;
146   
    }
146   
    }
147   
    return hash;
147   
    return hash;
148   
}
148   
}
149  
149  
150   
} // grammar
150   
} // grammar
151   
} // urls
151   
} // urls
152   
} // boost
152   
} // boost
153  
153