summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/xkbcommon/src/atom.c
blob: 044f56681a121b50caf234c515acf206279736d5 (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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
/***********************************************************
 * Copyright 1987, 1998  The Open Group
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name of The Open Group shall not be
 * used in advertising or otherwise to promote the sale, use or other dealings
 * in this Software without prior written authorization from The Open Group.
 *
 *
 * Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
 *
 *                      All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and that
 * both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of Digital not be
 * used in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 *
 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
 * DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
 * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 *
 ******************************************************************/

/************************************************************
 * Copyright 1994 by Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of Silicon Graphics not be
 * used in advertising or publicity pertaining to distribution
 * of the software without specific prior written permission.
 * Silicon Graphics makes no representation about the suitability
 * of this software for any purpose. It is provided "as is"
 * without any express or implied warranty.
 *
 * SILICON GRAPHICS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
 * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
 * GRAPHICS BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION  WITH
 * THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 ********************************************************/

#include "utils.h"
#include "atom.h"

struct atom_node {
    xkb_atom_t left, right;
    xkb_atom_t atom;
    unsigned int fingerprint;
    char *string;
};

struct atom_table {
    xkb_atom_t root;
    darray(struct atom_node) table;
};

struct atom_table *
atom_table_new(void)
{
    struct atom_table *table;

    table = calloc(1, sizeof(*table));
    if (!table)
        return NULL;

    darray_init(table->table);
    /* The original throw-away root is here, at the illegal atom 0. */
    darray_resize0(table->table, 1);

    return table;
}

void
atom_table_free(struct atom_table *table)
{
    struct atom_node *node;

    if (!table)
        return;

    darray_foreach(node, table->table)
        free(node->string);
    darray_free(table->table);
    free(table);
}

const char *
atom_text(struct atom_table *table, xkb_atom_t atom)
{
    if (atom == XKB_ATOM_NONE || atom >= darray_size(table->table))
        return NULL;

    return darray_item(table->table, atom).string;
}

static bool
find_atom_pointer(struct atom_table *table, const char *string, size_t len,
                  xkb_atom_t **atomp_out, unsigned int *fingerprint_out)
{
    xkb_atom_t *atomp = &table->root;
    unsigned int fingerprint = 0;
    bool found = false;

    for (size_t i = 0; i < (len + 1) / 2; i++) {
        fingerprint = fingerprint * 27 + string[i];
        fingerprint = fingerprint * 27 + string[len - 1 - i];
    }

    while (*atomp != XKB_ATOM_NONE) {
        struct atom_node *node = &darray_item(table->table, *atomp);

        if (fingerprint < node->fingerprint) {
            atomp = &node->left;
        }
        else if (fingerprint > node->fingerprint) {
            atomp = &node->right;
        }
        else {
            /* Now start testing the strings. */
            const int cmp = strncmp(string, node->string, len);
            if (cmp < 0 || (cmp == 0 && len < strlen(node->string))) {
                atomp = &node->left;
            }
            else if (cmp > 0) {
                atomp = &node->right;
            }
            else {
                found = true;
                break;
            }
        }
    }

    if (fingerprint_out)
        *fingerprint_out = fingerprint;
    if (atomp_out)
        *atomp_out = atomp;
    return found;
}

xkb_atom_t
atom_lookup(struct atom_table *table, const char *string, size_t len)
{
    xkb_atom_t *atomp;

    if (!string)
        return XKB_ATOM_NONE;

    if (!find_atom_pointer(table, string, len, &atomp, NULL))
        return XKB_ATOM_NONE;

    return *atomp;
}

/*
 * If steal is true, we do not strdup @string; therefore it must be
 * dynamically allocated, NUL-terminated, not be free'd by the caller
 * and not be used afterwards. Use to avoid some redundant allocations.
 */
xkb_atom_t
atom_intern(struct atom_table *table, const char *string, size_t len,
            bool steal)
{
    xkb_atom_t *atomp;
    struct atom_node node;
    unsigned int fingerprint;

    if (!string)
        return XKB_ATOM_NONE;

    if (find_atom_pointer(table, string, len, &atomp, &fingerprint)) {
        if (steal)
            free(UNCONSTIFY(string));
        return *atomp;
    }

    if (steal) {
        node.string = UNCONSTIFY(string);
    }
    else {
        node.string = strndup(string, len);
        if (!node.string)
            return XKB_ATOM_NONE;
    }

    node.left = node.right = XKB_ATOM_NONE;
    node.fingerprint = fingerprint;
    node.atom = darray_size(table->table);
    /* Do this before the append, as it may realloc and change the offsets. */
    *atomp = node.atom;
    darray_append(table->table, node);

    return node.atom;
}