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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /gfx/harfbuzz/src/hb-cache.hh | |
parent | Initial commit. (diff) | |
download | firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/harfbuzz/src/hb-cache.hh')
-rw-r--r-- | gfx/harfbuzz/src/hb-cache.hh | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-cache.hh b/gfx/harfbuzz/src/hb-cache.hh new file mode 100644 index 0000000000..bf26d96be4 --- /dev/null +++ b/gfx/harfbuzz/src/hb-cache.hh @@ -0,0 +1,80 @@ +/* + * Copyright © 2012 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#ifndef HB_CACHE_HH +#define HB_CACHE_HH + +#include "hb.hh" + + +/* Implements a lock-free cache for int->int functions. */ + +template <unsigned int key_bits, unsigned int value_bits, unsigned int cache_bits> +struct hb_cache_t +{ + static_assert ((key_bits >= cache_bits), ""); + static_assert ((key_bits + value_bits - cache_bits <= 8 * sizeof (hb_atomic_int_t)), ""); + static_assert (sizeof (hb_atomic_int_t) == sizeof (unsigned int), ""); + + void init () { clear (); } + void fini () {} + + void clear () + { + for (unsigned i = 0; i < ARRAY_LENGTH (values); i++) + values[i].set_relaxed (-1); + } + + bool get (unsigned int key, unsigned int *value) const + { + unsigned int k = key & ((1u<<cache_bits)-1); + unsigned int v = values[k].get_relaxed (); + if ((key_bits + value_bits - cache_bits == 8 * sizeof (hb_atomic_int_t) && v == (unsigned int) -1) || + (v >> value_bits) != (key >> cache_bits)) + return false; + *value = v & ((1u<<value_bits)-1); + return true; + } + + bool set (unsigned int key, unsigned int value) + { + if (unlikely ((key >> key_bits) || (value >> value_bits))) + return false; /* Overflows */ + unsigned int k = key & ((1u<<cache_bits)-1); + unsigned int v = ((key>>cache_bits)<<value_bits) | value; + values[k].set_relaxed (v); + return true; + } + + private: + hb_atomic_int_t values[1u<<cache_bits]; +}; + +typedef hb_cache_t<21, 16, 8> hb_cmap_cache_t; +typedef hb_cache_t<16, 24, 8> hb_advance_cache_t; + + +#endif /* HB_CACHE_HH */ |