aboutsummaryrefslogtreecommitdiffstats
path: root/src/core/SkTSearch.cpp
blob: ccdcecb9b90397e3d2c6bc4186ddce7f0e5ec517 (plain)
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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179

/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#include "SkTSearch.h"
#include <ctype.h>

static inline const char* index_into_base(const char*const* base, int index,
                                          size_t elemSize)
{
    return *(const char*const*)((const char*)base + index * elemSize);
}

int SkStrSearch(const char*const* base, int count, const char target[],
                size_t target_len, size_t elemSize)
{
    if (count <= 0)
        return ~0;

    SkASSERT(base != NULL);

    int lo = 0;
    int hi = count - 1;

    while (lo < hi)
    {
        int mid = (hi + lo) >> 1;
        const char* elem = index_into_base(base, mid, elemSize);

        int cmp = strncmp(elem, target, target_len);
        if (cmp < 0)
            lo = mid + 1;
        else if (cmp > 0 || strlen(elem) > target_len)
            hi = mid;
        else
            return mid;
    }

    const char* elem = index_into_base(base, hi, elemSize);
    int cmp = strncmp(elem, target, target_len);
    if (cmp || strlen(elem) > target_len)
    {
        if (cmp < 0)
            hi += 1;
        hi = ~hi;
    }
    return hi;
}

int SkStrSearch(const char*const* base, int count, const char target[],
                size_t elemSize)
{
    return SkStrSearch(base, count, target, strlen(target), elemSize);
}

int SkStrLCSearch(const char*const* base, int count, const char target[],
                  size_t len, size_t elemSize)
{
    SkASSERT(target);

    SkAutoAsciiToLC tolc(target, len);

    return SkStrSearch(base, count, tolc.lc(), len, elemSize);
}

int SkStrLCSearch(const char*const* base, int count, const char target[],
                  size_t elemSize)
{
    return SkStrLCSearch(base, count, target, strlen(target), elemSize);
}

//////////////////////////////////////////////////////////////////////////////

SkAutoAsciiToLC::SkAutoAsciiToLC(const char str[], size_t len)
{
    // see if we need to compute the length
    if ((long)len < 0) {
        len = strlen(str);
    }
    fLength = len;

    // assign lc to our preallocated storage if len is small enough, or allocate
    // it on the heap
    char*   lc;
    if (len <= STORAGE) {
        lc = fStorage;
    } else {
        lc = (char*)sk_malloc_throw(len + 1);
    }
    fLC = lc;
    
    // convert any asii to lower-case. we let non-ascii (utf8) chars pass
    // through unchanged
    for (int i = (int)(len - 1); i >= 0; --i) {
        int c = str[i];
        if ((c & 0x80) == 0) {   // is just ascii
            c = tolower(c);
        }
        lc[i] = c;
    }
    lc[len] = 0;
}

SkAutoAsciiToLC::~SkAutoAsciiToLC()
{
    if (fLC != fStorage) {
        sk_free(fLC);
    }
}

//////////////////////////////////////////////////////////////////////////////

#define SK_QSortTempSize    16

static inline void sk_qsort_swap(char a[], char b[], size_t elemSize)
{
    char    tmp[SK_QSortTempSize];

    while (elemSize > 0)
    {
        size_t size = elemSize;
        if (size > SK_QSortTempSize)
            size = SK_QSortTempSize;
        elemSize -= size;

        memcpy(tmp, a, size);
        memcpy(a, b, size);
        memcpy(b, tmp, size);
        a += size;
        b += size;
    }
}

static void SkQSort_Partition(char* first, char* last, size_t elemSize, SkQSortCompareProc compare)
{
    char*   left = first;
    char*   rite = last;
    char*   pivot = left;

    while (left <= rite)
    {
        while (left < last && compare(left, pivot) < 0)
            left += elemSize;
        while (first < rite && compare(rite, pivot) > 0)
            rite -= elemSize;
        if (left <= rite)
        {
            if (left < rite)
            {
                SkASSERT(compare(left, rite) >= 0);
                sk_qsort_swap(left, rite, elemSize);
            }
            left += elemSize;
            rite -= elemSize;
        }
    }
    if (first < rite)
        SkQSort_Partition(first, rite, elemSize, compare);
    if (left < last)
        SkQSort_Partition(left, last, elemSize, compare);
}

void SkQSort(void* base, size_t count, size_t elemSize, SkQSortCompareProc compare)
{
    SkASSERT(base);
    SkASSERT(compare);
    SkASSERT(elemSize > 0);

    if (count <= 1)
        return;

    SkQSort_Partition((char*)base, (char*)base + (count - 1) * elemSize, elemSize, compare);
}