gfx/harfbuzz/src/hb-shaper.cc@925c144e1f1f (annotated)
gfx/harfbuzz/src/hb-shaper.cc
Fri, 16 Jan 2015 18:13:44 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Fri, 16 Jan 2015 18:13:44 +0100
- branch
- TOR_BUG_9701
- changeset 14
- 925c144e1f1f
- permissions
- -rw-r--r--
Integrate suggestion from review to improve consistency with existing code.
| michael@0 | 1 | /* |
| michael@0 | 2 | * Copyright © 2012 Google, Inc. |
| michael@0 | 3 | * |
| michael@0 | 4 | * This is part of HarfBuzz, a text shaping library. |
| michael@0 | 5 | * |
| michael@0 | 6 | * Permission is hereby granted, without written agreement and without |
| michael@0 | 7 | * license or royalty fees, to use, copy, modify, and distribute this |
| michael@0 | 8 | * software and its documentation for any purpose, provided that the |
| michael@0 | 9 | * above copyright notice and the following two paragraphs appear in |
| michael@0 | 10 | * all copies of this software. |
| michael@0 | 11 | * |
| michael@0 | 12 | * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR |
| michael@0 | 13 | * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES |
| michael@0 | 14 | * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN |
| michael@0 | 15 | * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH |
| michael@0 | 16 | * DAMAGE. |
| michael@0 | 17 | * |
| michael@0 | 18 | * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, |
| michael@0 | 19 | * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| michael@0 | 20 | * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS |
| michael@0 | 21 | * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO |
| michael@0 | 22 | * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
| michael@0 | 23 | * |
| michael@0 | 24 | * Google Author(s): Behdad Esfahbod |
| michael@0 | 25 | */ |
| michael@0 | 26 | |
| michael@0 | 27 | #include "hb-private.hh" |
| michael@0 | 28 | #include "hb-shaper-private.hh" |
| michael@0 | 29 | #include "hb-atomic-private.hh" |
| michael@0 | 30 | |
| michael@0 | 31 | |
| michael@0 | 32 | static const hb_shaper_pair_t all_shapers[] = { |
| michael@0 | 33 | #define HB_SHAPER_IMPLEMENT(name) {#name, _hb_##name##_shape}, |
| michael@0 | 34 | #include "hb-shaper-list.hh" |
| michael@0 | 35 | #undef HB_SHAPER_IMPLEMENT |
| michael@0 | 36 | }; |
| michael@0 | 37 | |
| michael@0 | 38 | |
| michael@0 | 39 | /* Thread-safe, lock-free, shapers */ |
| michael@0 | 40 | |
| michael@0 | 41 | static const hb_shaper_pair_t *static_shapers; |
| michael@0 | 42 | |
| michael@0 | 43 | static inline |
| michael@0 | 44 | void free_static_shapers (void) |
| michael@0 | 45 | { |
| michael@0 | 46 | if (unlikely (static_shapers != all_shapers)) |
| michael@0 | 47 | free ((void *) static_shapers); |
| michael@0 | 48 | } |
| michael@0 | 49 | |
| michael@0 | 50 | const hb_shaper_pair_t * |
| michael@0 | 51 | _hb_shapers_get (void) |
| michael@0 | 52 | { |
| michael@0 | 53 | retry: |
| michael@0 | 54 | hb_shaper_pair_t *shapers = (hb_shaper_pair_t *) hb_atomic_ptr_get (&static_shapers); |
| michael@0 | 55 | |
| michael@0 | 56 | if (unlikely (!shapers)) |
| michael@0 | 57 | { |
| michael@0 | 58 | char *env = getenv ("HB_SHAPER_LIST"); |
| michael@0 | 59 | if (!env || !*env) { |
| michael@0 | 60 | (void) hb_atomic_ptr_cmpexch (&static_shapers, NULL, &all_shapers[0]); |
| michael@0 | 61 | return (const hb_shaper_pair_t *) all_shapers; |
| michael@0 | 62 | } |
| michael@0 | 63 | |
| michael@0 | 64 | /* Not found; allocate one. */ |
| michael@0 | 65 | shapers = (hb_shaper_pair_t *) malloc (sizeof (all_shapers)); |
| michael@0 | 66 | if (unlikely (!shapers)) { |
| michael@0 | 67 | (void) hb_atomic_ptr_cmpexch (&static_shapers, NULL, &all_shapers[0]); |
| michael@0 | 68 | return (const hb_shaper_pair_t *) all_shapers; |
| michael@0 | 69 | } |
| michael@0 | 70 | |
| michael@0 | 71 | memcpy (shapers, all_shapers, sizeof (all_shapers)); |
| michael@0 | 72 | |
| michael@0 | 73 | /* Reorder shaper list to prefer requested shapers. */ |
| michael@0 | 74 | unsigned int i = 0; |
| michael@0 | 75 | char *end, *p = env; |
| michael@0 | 76 | for (;;) { |
| michael@0 | 77 | end = strchr (p, ','); |
| michael@0 | 78 | if (!end) |
| michael@0 | 79 | end = p + strlen (p); |
| michael@0 | 80 | |
| michael@0 | 81 | for (unsigned int j = i; j < ARRAY_LENGTH (all_shapers); j++) |
| michael@0 | 82 | if (end - p == (int) strlen (shapers[j].name) && |
| michael@0 | 83 | 0 == strncmp (shapers[j].name, p, end - p)) |
| michael@0 | 84 | { |
| michael@0 | 85 | /* Reorder this shaper to position i */ |
| michael@0 | 86 | struct hb_shaper_pair_t t = shapers[j]; |
| michael@0 | 87 | memmove (&shapers[i + 1], &shapers[i], sizeof (shapers[i]) * (j - i)); |
| michael@0 | 88 | shapers[i] = t; |
| michael@0 | 89 | i++; |
| michael@0 | 90 | } |
| michael@0 | 91 | |
| michael@0 | 92 | if (!*end) |
| michael@0 | 93 | break; |
| michael@0 | 94 | else |
| michael@0 | 95 | p = end + 1; |
| michael@0 | 96 | } |
| michael@0 | 97 | |
| michael@0 | 98 | if (!hb_atomic_ptr_cmpexch (&static_shapers, NULL, shapers)) { |
| michael@0 | 99 | free (shapers); |
| michael@0 | 100 | goto retry; |
| michael@0 | 101 | } |
| michael@0 | 102 | |
| michael@0 | 103 | #ifdef HAVE_ATEXIT |
| michael@0 | 104 | atexit (free_static_shapers); /* First person registers atexit() callback. */ |
| michael@0 | 105 | #endif |
| michael@0 | 106 | } |
| michael@0 | 107 | |
| michael@0 | 108 | return shapers; |
| michael@0 | 109 | } |
