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comparison: gfx/harfbuzz/src/hb-shaper.cc
gfx/harfbuzz/src/hb-shaper.cc
- branch
- TOR_BUG_9701
- changeset 14
- 925c144e1f1f
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| -1:000000000000 | 0:575dab2476ba |
|---|---|
| 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-private.hh" | |
| 28 #include "hb-shaper-private.hh" | |
| 29 #include "hb-atomic-private.hh" | |
| 30 | |
| 31 | |
| 32 static const hb_shaper_pair_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 | |
| 39 /* Thread-safe, lock-free, shapers */ | |
| 40 | |
| 41 static const hb_shaper_pair_t *static_shapers; | |
| 42 | |
| 43 static inline | |
| 44 void free_static_shapers (void) | |
| 45 { | |
| 46 if (unlikely (static_shapers != all_shapers)) | |
| 47 free ((void *) static_shapers); | |
| 48 } | |
| 49 | |
| 50 const hb_shaper_pair_t * | |
| 51 _hb_shapers_get (void) | |
| 52 { | |
| 53 retry: | |
| 54 hb_shaper_pair_t *shapers = (hb_shaper_pair_t *) hb_atomic_ptr_get (&static_shapers); | |
| 55 | |
| 56 if (unlikely (!shapers)) | |
| 57 { | |
| 58 char *env = getenv ("HB_SHAPER_LIST"); | |
| 59 if (!env || !*env) { | |
| 60 (void) hb_atomic_ptr_cmpexch (&static_shapers, NULL, &all_shapers[0]); | |
| 61 return (const hb_shaper_pair_t *) all_shapers; | |
| 62 } | |
| 63 | |
| 64 /* Not found; allocate one. */ | |
| 65 shapers = (hb_shaper_pair_t *) malloc (sizeof (all_shapers)); | |
| 66 if (unlikely (!shapers)) { | |
| 67 (void) hb_atomic_ptr_cmpexch (&static_shapers, NULL, &all_shapers[0]); | |
| 68 return (const hb_shaper_pair_t *) all_shapers; | |
| 69 } | |
| 70 | |
| 71 memcpy (shapers, all_shapers, sizeof (all_shapers)); | |
| 72 | |
| 73 /* Reorder shaper list to prefer requested shapers. */ | |
| 74 unsigned int i = 0; | |
| 75 char *end, *p = env; | |
| 76 for (;;) { | |
| 77 end = strchr (p, ','); | |
| 78 if (!end) | |
| 79 end = p + strlen (p); | |
| 80 | |
| 81 for (unsigned int j = i; j < ARRAY_LENGTH (all_shapers); j++) | |
| 82 if (end - p == (int) strlen (shapers[j].name) && | |
| 83 0 == strncmp (shapers[j].name, p, end - p)) | |
| 84 { | |
| 85 /* Reorder this shaper to position i */ | |
| 86 struct hb_shaper_pair_t t = shapers[j]; | |
| 87 memmove (&shapers[i + 1], &shapers[i], sizeof (shapers[i]) * (j - i)); | |
| 88 shapers[i] = t; | |
| 89 i++; | |
| 90 } | |
| 91 | |
| 92 if (!*end) | |
| 93 break; | |
| 94 else | |
| 95 p = end + 1; | |
| 96 } | |
| 97 | |
| 98 if (!hb_atomic_ptr_cmpexch (&static_shapers, NULL, shapers)) { | |
| 99 free (shapers); | |
| 100 goto retry; | |
| 101 } | |
| 102 | |
| 103 #ifdef HAVE_ATEXIT | |
| 104 atexit (free_static_shapers); /* First person registers atexit() callback. */ | |
| 105 #endif | |
| 106 } | |
| 107 | |
| 108 return shapers; | |
| 109 } |
