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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /gfx/harfbuzz/src/hb-cache.hh | |
parent | Initial commit. (diff) | |
download | firefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
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 | 86 |
1 files changed, 86 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..f8c8108f1f --- /dev/null +++ b/gfx/harfbuzz/src/hb-cache.hh @@ -0,0 +1,86 @@ +/* + * 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 lockfree cache for int->int functions. */ + +template <unsigned int key_bits=16, + unsigned int value_bits=8 + 32 - key_bits, + unsigned int cache_bits=8, + bool thread_safe=true> +struct hb_cache_t +{ + using item_t = typename std::conditional<thread_safe, + hb_atomic_int_t, + typename std::conditional<key_bits + value_bits - cache_bits <= 16, + short, + int>::type + >::type; + + static_assert ((key_bits >= cache_bits), ""); + static_assert ((key_bits + value_bits <= cache_bits + 8 * sizeof (item_t)), ""); + + void init () { clear (); } + void fini () {} + + void clear () + { + for (unsigned i = 0; i < ARRAY_LENGTH (values); i++) + values[i] = -1; + } + + bool get (unsigned int key, unsigned int *value) const + { + unsigned int k = key & ((1u<<cache_bits)-1); + unsigned int v = values[k]; + if ((key_bits + value_bits - cache_bits == 8 * sizeof (item_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] = v; + return true; + } + + private: + item_t values[1u<<cache_bits]; +}; + + +#endif /* HB_CACHE_HH */ |