1/*
2 * Copyright © 2012 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27#include "hb.hh"
28#include "hb-shaper.hh"
29#include "hb-machinery.hh"
30
31
32static const hb_shaper_entry_t all_shapers[] = {
33#define HB_SHAPER_IMPLEMENT(name) {#name, _hb_##name##_shape},
34#include "hb-shaper-list.hh"
35#undef HB_SHAPER_IMPLEMENT
36};
37
38#if HB_USE_ATEXIT
39static void free_static_shapers ();
40#endif
41
42static struct hb_shapers_lazy_loader_t : hb_lazy_loader_t<const hb_shaper_entry_t,
43 hb_shapers_lazy_loader_t>
44{
45 static hb_shaper_entry_t *create ()
46 {
47 char *env = getenv ("HB_SHAPER_LIST");
48 if (!env || !*env)
49 return nullptr;
50
51 hb_shaper_entry_t *shapers = (hb_shaper_entry_t *) calloc (1, sizeof (all_shapers));
52 if (unlikely (!shapers))
53 return nullptr;
54
55 memcpy (shapers, all_shapers, sizeof (all_shapers));
56
57 /* Reorder shaper list to prefer requested shapers. */
58 unsigned int i = 0;
59 char *end, *p = env;
60 for (;;)
61 {
62 end = strchr (p, ',');
63 if (!end)
64 end = p + strlen (p);
65
66 for (unsigned int j = i; j < ARRAY_LENGTH (all_shapers); j++)
67 if (end - p == (int) strlen (shapers[j].name) &&
68 0 == strncmp (shapers[j].name, p, end - p))
69 {
70 /* Reorder this shaper to position i */
71 struct hb_shaper_entry_t t = shapers[j];
72 memmove (&shapers[i + 1], &shapers[i], sizeof (shapers[i]) * (j - i));
73 shapers[i] = t;
74 i++;
75 }
76
77 if (!*end)
78 break;
79 else
80 p = end + 1;
81 }
82
83#if HB_USE_ATEXIT
84 atexit (free_static_shapers);
85#endif
86
87 return shapers;
88 }
89 static void destroy (const hb_shaper_entry_t *p) { free ((void *) p); }
90 static const hb_shaper_entry_t *get_null () { return all_shapers; }
91} static_shapers;
92
93#if HB_USE_ATEXIT
94static
95void free_static_shapers ()
96{
97 static_shapers.free_instance ();
98}
99#endif
100
101const hb_shaper_entry_t *
102_hb_shapers_get ()
103{
104 return static_shapers.get_unconst ();
105}
106