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Diffstat (limited to 'Build/source/libs/harfbuzz/harfbuzz-0.9.36/src/hb-cache-private.hh')
-rw-r--r-- | Build/source/libs/harfbuzz/harfbuzz-0.9.36/src/hb-cache-private.hh | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/Build/source/libs/harfbuzz/harfbuzz-0.9.36/src/hb-cache-private.hh b/Build/source/libs/harfbuzz/harfbuzz-0.9.36/src/hb-cache-private.hh new file mode 100644 index 00000000000..19b70b7e395 --- /dev/null +++ b/Build/source/libs/harfbuzz/harfbuzz-0.9.36/src/hb-cache-private.hh @@ -0,0 +1,74 @@ +/* + * 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_PRIVATE_HH +#define HB_CACHE_PRIVATE_HH + +#include "hb-private.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 +{ + ASSERT_STATIC (key_bits >= cache_bits); + ASSERT_STATIC (key_bits + value_bits - cache_bits < 8 * sizeof (unsigned int)); + + inline void clear (void) + { + memset (values, 255, sizeof (values)); + } + + inline bool get (unsigned int key, unsigned int *value) + { + unsigned int k = key & ((1<<cache_bits)-1); + unsigned int v = values[k]; + if ((v >> value_bits) != (key >> cache_bits)) + return false; + *value = v & ((1<<value_bits)-1); + return true; + } + + inline bool set (unsigned int key, unsigned int value) + { + if (unlikely ((key >> key_bits) || (value >> value_bits))) + return false; /* Overflows */ + unsigned int k = key & ((1<<cache_bits)-1); + unsigned int v = ((key>>cache_bits)<<value_bits) | value; + values[k] = v; + return true; + } + + private: + unsigned int values[1<<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_PRIVATE_HH */ |