| /* |
| * 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_SET_PRIVATE_HH |
| #define HB_SET_PRIVATE_HH |
| |
| #include "hb-private.hh" |
| #include "hb-object-private.hh" |
| |
| |
| /* |
| * The set digests here implement various "filters" that support |
| * "approximate member query". Conceptually these are like Bloom |
| * Filter and Quotient Filter, however, much smaller, faster, and |
| * designed to fit the requirements of our uses for glyph coverage |
| * queries. |
| * |
| * Our filters are highly accurate if the lookup covers fairly local |
| * set of glyphs, but fully flooded and ineffective if coverage is |
| * all over the place. |
| * |
| * The frozen-set can be used instead of a digest, to trade more |
| * memory for 100% accuracy, but in practice, that doesn't look like |
| * an attractive trade-off. |
| */ |
| |
| template <typename mask_t, unsigned int shift> |
| struct hb_set_digest_lowest_bits_t |
| { |
| ASSERT_POD (); |
| |
| static const unsigned int mask_bytes = sizeof (mask_t); |
| static const unsigned int mask_bits = sizeof (mask_t) * 8; |
| static const unsigned int num_bits = 0 |
| + (mask_bytes >= 1 ? 3 : 0) |
| + (mask_bytes >= 2 ? 1 : 0) |
| + (mask_bytes >= 4 ? 1 : 0) |
| + (mask_bytes >= 8 ? 1 : 0) |
| + (mask_bytes >= 16? 1 : 0) |
| + 0; |
| |
| ASSERT_STATIC (shift < sizeof (hb_codepoint_t) * 8); |
| ASSERT_STATIC (shift + num_bits <= sizeof (hb_codepoint_t) * 8); |
| |
| inline void init (void) { |
| mask = 0; |
| } |
| |
| inline void add (hb_codepoint_t g) { |
| mask |= mask_for (g); |
| } |
| |
| inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { |
| if ((b >> shift) - (a >> shift) >= mask_bits - 1) |
| mask = (mask_t) -1; |
| else { |
| mask_t ma = mask_for (a); |
| mask_t mb = mask_for (b); |
| mask |= mb + (mb - ma) - (mb < ma); |
| } |
| } |
| |
| inline bool may_have (hb_codepoint_t g) const { |
| return !!(mask & mask_for (g)); |
| } |
| |
| private: |
| |
| static inline mask_t mask_for (hb_codepoint_t g) { |
| return ((mask_t) 1) << ((g >> shift) & (mask_bits - 1)); |
| } |
| mask_t mask; |
| }; |
| |
| template <typename head_t, typename tail_t> |
| struct hb_set_digest_combiner_t |
| { |
| ASSERT_POD (); |
| |
| inline void init (void) { |
| head.init (); |
| tail.init (); |
| } |
| |
| inline void add (hb_codepoint_t g) { |
| head.add (g); |
| tail.add (g); |
| } |
| |
| inline void add_range (hb_codepoint_t a, hb_codepoint_t b) { |
| head.add_range (a, b); |
| tail.add_range (a, b); |
| } |
| |
| inline bool may_have (hb_codepoint_t g) const { |
| return head.may_have (g) && tail.may_have (g); |
| } |
| |
| private: |
| head_t head; |
| tail_t tail; |
| }; |
| |
| |
| /* |
| * hb_set_digest_t |
| * |
| * This is a combination of digests that performs "best". |
| * There is not much science to this: it's a result of intuition |
| * and testing. |
| */ |
| typedef hb_set_digest_combiner_t |
| < |
| hb_set_digest_lowest_bits_t<unsigned long, 4>, |
| hb_set_digest_combiner_t |
| < |
| hb_set_digest_lowest_bits_t<unsigned long, 0>, |
| hb_set_digest_lowest_bits_t<unsigned long, 9> |
| > |
| > hb_set_digest_t; |
| |
| |
| |
| /* |
| * hb_set_t |
| */ |
| |
| |
| /* TODO Make this faster and memmory efficient. */ |
| |
| struct hb_set_t |
| { |
| friend struct hb_frozen_set_t; |
| |
| hb_object_header_t header; |
| ASSERT_POD (); |
| bool in_error; |
| |
| inline void init (void) { |
| hb_object_init (this); |
| clear (); |
| } |
| inline void fini (void) { |
| } |
| inline void clear (void) { |
| if (unlikely (hb_object_is_inert (this))) |
| return; |
| in_error = false; |
| memset (elts, 0, sizeof elts); |
| } |
| inline bool is_empty (void) const { |
| for (unsigned int i = 0; i < ARRAY_LENGTH (elts); i++) |
| if (elts[i]) |
| return false; |
| return true; |
| } |
| inline void add (hb_codepoint_t g) |
| { |
| if (unlikely (in_error)) return; |
| if (unlikely (g == INVALID)) return; |
| if (unlikely (g > MAX_G)) return; |
| elt (g) |= mask (g); |
| } |
| inline void add_range (hb_codepoint_t a, hb_codepoint_t b) |
| { |
| if (unlikely (in_error)) return; |
| /* TODO Speedup */ |
| for (unsigned int i = a; i < b + 1; i++) |
| add (i); |
| } |
| inline void del (hb_codepoint_t g) |
| { |
| if (unlikely (in_error)) return; |
| if (unlikely (g > MAX_G)) return; |
| elt (g) &= ~mask (g); |
| } |
| inline void del_range (hb_codepoint_t a, hb_codepoint_t b) |
| { |
| if (unlikely (in_error)) return; |
| /* TODO Speedup */ |
| for (unsigned int i = a; i < b + 1; i++) |
| del (i); |
| } |
| inline bool has (hb_codepoint_t g) const |
| { |
| if (unlikely (g > MAX_G)) return false; |
| return !!(elt (g) & mask (g)); |
| } |
| inline bool intersects (hb_codepoint_t first, |
| hb_codepoint_t last) const |
| { |
| if (unlikely (first > MAX_G)) return false; |
| if (unlikely (last > MAX_G)) last = MAX_G; |
| unsigned int end = last + 1; |
| for (hb_codepoint_t i = first; i < end; i++) |
| if (has (i)) |
| return true; |
| return false; |
| } |
| inline bool is_equal (const hb_set_t *other) const |
| { |
| for (unsigned int i = 0; i < ELTS; i++) |
| if (elts[i] != other->elts[i]) |
| return false; |
| return true; |
| } |
| inline void set (const hb_set_t *other) |
| { |
| if (unlikely (in_error)) return; |
| for (unsigned int i = 0; i < ELTS; i++) |
| elts[i] = other->elts[i]; |
| } |
| inline void union_ (const hb_set_t *other) |
| { |
| if (unlikely (in_error)) return; |
| for (unsigned int i = 0; i < ELTS; i++) |
| elts[i] |= other->elts[i]; |
| } |
| inline void intersect (const hb_set_t *other) |
| { |
| if (unlikely (in_error)) return; |
| for (unsigned int i = 0; i < ELTS; i++) |
| elts[i] &= other->elts[i]; |
| } |
| inline void subtract (const hb_set_t *other) |
| { |
| if (unlikely (in_error)) return; |
| for (unsigned int i = 0; i < ELTS; i++) |
| elts[i] &= ~other->elts[i]; |
| } |
| inline void symmetric_difference (const hb_set_t *other) |
| { |
| if (unlikely (in_error)) return; |
| for (unsigned int i = 0; i < ELTS; i++) |
| elts[i] ^= other->elts[i]; |
| } |
| inline void invert (void) |
| { |
| if (unlikely (in_error)) return; |
| for (unsigned int i = 0; i < ELTS; i++) |
| elts[i] = ~elts[i]; |
| } |
| inline bool next (hb_codepoint_t *codepoint) const |
| { |
| if (unlikely (*codepoint == INVALID)) { |
| hb_codepoint_t i = get_min (); |
| if (i != INVALID) { |
| *codepoint = i; |
| return true; |
| } else { |
| *codepoint = INVALID; |
| return false; |
| } |
| } |
| for (hb_codepoint_t i = *codepoint + 1; i < MAX_G + 1; i++) |
| if (has (i)) { |
| *codepoint = i; |
| return true; |
| } |
| *codepoint = INVALID; |
| return false; |
| } |
| inline bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const |
| { |
| hb_codepoint_t i; |
| |
| i = *last; |
| if (!next (&i)) |
| { |
| *last = *first = INVALID; |
| return false; |
| } |
| |
| *last = *first = i; |
| while (next (&i) && i == *last + 1) |
| (*last)++; |
| |
| return true; |
| } |
| |
| inline unsigned int get_population (void) const |
| { |
| unsigned int count = 0; |
| for (unsigned int i = 0; i < ELTS; i++) |
| count += _hb_popcount32 (elts[i]); |
| return count; |
| } |
| inline hb_codepoint_t get_min (void) const |
| { |
| for (unsigned int i = 0; i < ELTS; i++) |
| if (elts[i]) |
| for (unsigned int j = 0; j < BITS; j++) |
| if (elts[i] & (1 << j)) |
| return i * BITS + j; |
| return INVALID; |
| } |
| inline hb_codepoint_t get_max (void) const |
| { |
| for (unsigned int i = ELTS; i; i--) |
| if (elts[i - 1]) |
| for (unsigned int j = BITS; j; j--) |
| if (elts[i - 1] & (1 << (j - 1))) |
| return (i - 1) * BITS + (j - 1); |
| return INVALID; |
| } |
| |
| typedef uint32_t elt_t; |
| static const unsigned int MAX_G = 65536 - 1; /* XXX Fix this... */ |
| static const unsigned int SHIFT = 5; |
| static const unsigned int BITS = (1 << SHIFT); |
| static const unsigned int MASK = BITS - 1; |
| static const unsigned int ELTS = (MAX_G + 1 + (BITS - 1)) / BITS; |
| static const hb_codepoint_t INVALID = HB_SET_VALUE_INVALID; |
| |
| elt_t &elt (hb_codepoint_t g) { return elts[g >> SHIFT]; } |
| elt_t const &elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; } |
| elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & MASK); } |
| |
| elt_t elts[ELTS]; /* XXX 8kb */ |
| |
| ASSERT_STATIC (sizeof (elt_t) * 8 == BITS); |
| ASSERT_STATIC (sizeof (elt_t) * 8 * ELTS > MAX_G); |
| }; |
| |
| struct hb_frozen_set_t |
| { |
| static const unsigned int SHIFT = hb_set_t::SHIFT; |
| static const unsigned int BITS = hb_set_t::BITS; |
| static const unsigned int MASK = hb_set_t::MASK; |
| typedef hb_set_t::elt_t elt_t; |
| |
| inline void init (const hb_set_t &set) |
| { |
| start = count = 0; |
| elts = NULL; |
| |
| unsigned int max = set.get_max (); |
| if (max == set.INVALID) |
| return; |
| unsigned int min = set.get_min (); |
| const elt_t &min_elt = set.elt (min); |
| |
| start = min & ~MASK; |
| count = max - start + 1; |
| unsigned int num_elts = (count + BITS - 1) / BITS; |
| unsigned int elts_size = num_elts * sizeof (elt_t); |
| elts = (elt_t *) malloc (elts_size); |
| if (unlikely (!elts)) |
| { |
| start = count = 0; |
| return; |
| } |
| memcpy (elts, &min_elt, elts_size); |
| } |
| |
| inline void fini (void) |
| { |
| if (elts) |
| free (elts); |
| } |
| |
| inline bool has (hb_codepoint_t g) const |
| { |
| /* hb_codepoint_t is unsigned. */ |
| g -= start; |
| if (unlikely (g > count)) return false; |
| return !!(elt (g) & mask (g)); |
| } |
| |
| elt_t const &elt (hb_codepoint_t g) const { return elts[g >> SHIFT]; } |
| elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & MASK); } |
| |
| private: |
| hb_codepoint_t start, count; |
| elt_t *elts; |
| }; |
| |
| |
| #endif /* HB_SET_PRIVATE_HH */ |