1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/harfbuzz/src/hb-cache-private.hh Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,74 @@
1.4 +/*
1.5 + * Copyright © 2012 Google, Inc.
1.6 + *
1.7 + * This is part of HarfBuzz, a text shaping library.
1.8 + *
1.9 + * Permission is hereby granted, without written agreement and without
1.10 + * license or royalty fees, to use, copy, modify, and distribute this
1.11 + * software and its documentation for any purpose, provided that the
1.12 + * above copyright notice and the following two paragraphs appear in
1.13 + * all copies of this software.
1.14 + *
1.15 + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
1.16 + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
1.17 + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
1.18 + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
1.19 + * DAMAGE.
1.20 + *
1.21 + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
1.22 + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
1.23 + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
1.24 + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
1.25 + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
1.26 + *
1.27 + * Google Author(s): Behdad Esfahbod
1.28 + */
1.29 +
1.30 +#ifndef HB_CACHE_PRIVATE_HH
1.31 +#define HB_CACHE_PRIVATE_HH
1.32 +
1.33 +#include "hb-private.hh"
1.34 +
1.35 +
1.36 +/* Implements a lock-free cache for int->int functions. */
1.37 +
1.38 +template <unsigned int key_bits, unsigned int value_bits, unsigned int cache_bits>
1.39 +struct hb_cache_t
1.40 +{
1.41 + ASSERT_STATIC (key_bits >= cache_bits);
1.42 + ASSERT_STATIC (key_bits + value_bits - cache_bits < 8 * sizeof (unsigned int));
1.43 +
1.44 + inline void clear (void)
1.45 + {
1.46 + memset (values, 255, sizeof (values));
1.47 + }
1.48 +
1.49 + inline bool get (unsigned int key, unsigned int *value)
1.50 + {
1.51 + unsigned int k = key & ((1<<cache_bits)-1);
1.52 + unsigned int v = values[k];
1.53 + if ((v >> value_bits) != (key >> cache_bits))
1.54 + return false;
1.55 + *value = v & ((1<<value_bits)-1);
1.56 + return true;
1.57 + }
1.58 +
1.59 + inline bool set (unsigned int key, unsigned int value)
1.60 + {
1.61 + if (unlikely ((key >> key_bits) || (value >> value_bits)))
1.62 + return false; /* Overflows */
1.63 + unsigned int k = key & ((1<<cache_bits)-1);
1.64 + unsigned int v = ((key>>cache_bits)<<value_bits) | value;
1.65 + values[k] = v;
1.66 + return true;
1.67 + }
1.68 +
1.69 + private:
1.70 + unsigned int values[1<<cache_bits];
1.71 +};
1.72 +
1.73 +typedef hb_cache_t<21, 16, 8> hb_cmap_cache_t;
1.74 +typedef hb_cache_t<16, 24, 8> hb_advance_cache_t;
1.75 +
1.76 +
1.77 +#endif /* HB_CACHE_PRIVATE_HH */
