/* * Copyright © 2012,2017 Google, Inc. * Copyright © 2021 Behdad Esfahbod * * 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_BIT_SET_HH #define HB_BIT_SET_HH #include "hb.hh" #include "hb-bit-page.hh" #include "hb-machinery.hh" struct hb_bit_set_t { hb_bit_set_t () = default; ~hb_bit_set_t () = default; hb_bit_set_t (const hb_bit_set_t& other) : hb_bit_set_t () { set (other); } hb_bit_set_t ( hb_bit_set_t&& other) : hb_bit_set_t () { hb_swap (*this, other); } hb_bit_set_t& operator= (const hb_bit_set_t& other) { set (other); return *this; } hb_bit_set_t& operator= (hb_bit_set_t&& other) { hb_swap (*this, other); return *this; } friend void swap (hb_bit_set_t &a, hb_bit_set_t &b) { if (likely (!a.successful || !b.successful)) return; hb_swap (a.population, b.population); hb_swap (a.last_page_lookup, b.last_page_lookup); hb_swap (a.page_map, b.page_map); hb_swap (a.pages, b.pages); } void init () { successful = true; population = 0; last_page_lookup = 0; page_map.init (); pages.init (); } void fini () { page_map.fini (); pages.fini (); } using page_t = hb_bit_page_t; struct page_map_t { int cmp (const page_map_t &o) const { return cmp (o.major); } int cmp (uint32_t o_major) const { return (int) o_major - (int) major; } uint32_t major; uint32_t index; }; bool successful = true; /* Allocations successful */ mutable unsigned int population = 0; mutable hb_atomic_int_t last_page_lookup = 0; hb_sorted_vector_t page_map; hb_vector_t pages; void err () { if (successful) successful = false; } /* TODO Remove */ bool in_error () const { return !successful; } bool resize (unsigned int count) { if (unlikely (!successful)) return false; if (unlikely (!pages.resize (count) || !page_map.resize (count))) { pages.resize (page_map.length); successful = false; return false; } return true; } void alloc (unsigned sz) { sz >>= (page_t::PAGE_BITS_LOG_2 - 1); pages.alloc (sz); page_map.alloc (sz); } void reset () { successful = true; clear (); } void clear () { resize (0); if (likely (successful)) population = 0; } bool is_empty () const { unsigned int count = pages.length; for (unsigned int i = 0; i < count; i++) if (!pages[i].is_empty ()) return false; return true; } explicit operator bool () const { return !is_empty (); } uint32_t hash () const { uint32_t h = 0; for (auto &map : page_map) h = h * 31 + hb_hash (map.major) + hb_hash (pages[map.index]); return h; } private: void dirty () { population = UINT_MAX; } public: void add (hb_codepoint_t g) { if (unlikely (!successful)) return; if (unlikely (g == INVALID)) return; dirty (); page_t *page = page_for (g, true); if (unlikely (!page)) return; page->add (g); } bool add_range (hb_codepoint_t a, hb_codepoint_t b) { if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */ if (unlikely (a > b || a == INVALID || b == INVALID)) return false; dirty (); unsigned int ma = get_major (a); unsigned int mb = get_major (b); if (ma == mb) { page_t *page = page_for (a, true); if (unlikely (!page)) return false; page->add_range (a, b); } else { page_t *page = page_for (a, true); if (unlikely (!page)) return false; page->add_range (a, major_start (ma + 1) - 1); for (unsigned int m = ma + 1; m < mb; m++) { page = page_for (major_start (m), true); if (unlikely (!page)) return false; page->init1 (); } page = page_for (b, true); if (unlikely (!page)) return false; page->add_range (major_start (mb), b); } return true; } template void set_array (bool v, const T *array, unsigned int count, unsigned int stride=sizeof(T)) { if (unlikely (!successful)) return; if (!count) return; dirty (); hb_codepoint_t g = *array; while (count) { unsigned int m = get_major (g); page_t *page = page_for (g, v); if (unlikely (v && !page)) return; unsigned int start = major_start (m); unsigned int end = major_start (m + 1); do { if (v || page) /* The v check is to optimize out the page check if v is true. */ page->set (g, v); array = &StructAtOffsetUnaligned (array, stride); count--; } while (count && (g = *array, start <= g && g < end)); } } template void add_array (const T *array, unsigned int count, unsigned int stride=sizeof(T)) { set_array (true, array, count, stride); } template void add_array (const hb_array_t& arr) { add_array (&arr, arr.len ()); } template void del_array (const T *array, unsigned int count, unsigned int stride=sizeof(T)) { set_array (false, array, count, stride); } template void del_array (const hb_array_t& arr) { del_array (&arr, arr.len ()); } /* Might return false if array looks unsorted. * Used for faster rejection of corrupt data. */ template bool set_sorted_array (bool v, const T *array, unsigned int count, unsigned int stride=sizeof(T)) { if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */ if (unlikely (!count)) return true; dirty (); hb_codepoint_t g = *array; hb_codepoint_t last_g = g; while (count) { unsigned int m = get_major (g); page_t *page = page_for (g, v); if (unlikely (v && !page)) return false; unsigned int end = major_start (m + 1); do { /* If we try harder we can change the following comparison to <=; * Not sure if it's worth it. */ if (g < last_g) return false; last_g = g; if (v || page) /* The v check is to optimize out the page check if v is true. */ page->add (g); array = &StructAtOffsetUnaligned (array, stride); count--; } while (count && (g = *array, g < end)); } return true; } template bool add_sorted_array (const T *array, unsigned int count, unsigned int stride=sizeof(T)) { return set_sorted_array (true, array, count, stride); } template bool add_sorted_array (const hb_sorted_array_t& arr) { return add_sorted_array (&arr, arr.len ()); } template bool del_sorted_array (const T *array, unsigned int count, unsigned int stride=sizeof(T)) { return set_sorted_array (false, array, count, stride); } template bool del_sorted_array (const hb_sorted_array_t& arr) { return del_sorted_array (&arr, arr.len ()); } void del (hb_codepoint_t g) { if (unlikely (!successful)) return; page_t *page = page_for (g); if (!page) return; dirty (); page->del (g); } private: void del_pages (int ds, int de) { if (ds <= de) { // Pre-allocate the workspace that compact() will need so we can bail on allocation failure // before attempting to rewrite the page map. hb_vector_t compact_workspace; if (unlikely (!allocate_compact_workspace (compact_workspace))) return; unsigned int write_index = 0; for (unsigned int i = 0; i < page_map.length; i++) { int m = (int) page_map[i].major; if (m < ds || de < m) page_map[write_index++] = page_map[i]; } compact (compact_workspace, write_index); resize (write_index); } } public: void del_range (hb_codepoint_t a, hb_codepoint_t b) { if (unlikely (!successful)) return; if (unlikely (a > b || a == INVALID)) return; dirty (); unsigned int ma = get_major (a); unsigned int mb = get_major (b); /* Delete pages from ds through de if ds <= de. */ int ds = (a == major_start (ma))? (int) ma: (int) (ma + 1); int de = (b + 1 == major_start (mb + 1))? (int) mb: ((int) mb - 1); if (ds > de || (int) ma < ds) { page_t *page = page_for (a); if (page) { if (ma == mb) page->del_range (a, b); else page->del_range (a, major_start (ma + 1) - 1); } } if (de < (int) mb && ma != mb) { page_t *page = page_for (b); if (page) page->del_range (major_start (mb), b); } del_pages (ds, de); } bool get (hb_codepoint_t g) const { const page_t *page = page_for (g); if (!page) return false; return page->get (g); } /* Has interface. */ static constexpr bool SENTINEL = false; typedef bool value_t; value_t operator [] (hb_codepoint_t k) const { return get (k); } bool has (hb_codepoint_t k) const { return (*this)[k] != SENTINEL; } /* Predicate. */ bool operator () (hb_codepoint_t k) const { return has (k); } /* Sink interface. */ hb_bit_set_t& operator << (hb_codepoint_t v) { add (v); return *this; } hb_bit_set_t& operator << (const hb_pair_t& range) { add_range (range.first, range.second); return *this; } bool intersects (hb_codepoint_t first, hb_codepoint_t last) const { hb_codepoint_t c = first - 1; return next (&c) && c <= last; } void set (const hb_bit_set_t &other) { if (unlikely (!successful)) return; unsigned int count = other.pages.length; if (unlikely (!resize (count))) return; population = other.population; page_map = other.page_map; pages = other.pages; } bool is_equal (const hb_bit_set_t &other) const { if (has_population () && other.has_population () && population != other.population) return false; unsigned int na = pages.length; unsigned int nb = other.pages.length; unsigned int a = 0, b = 0; for (; a < na && b < nb; ) { if (page_at (a).is_empty ()) { a++; continue; } if (other.page_at (b).is_empty ()) { b++; continue; } if (page_map[a].major != other.page_map[b].major || !page_at (a).is_equal (other.page_at (b))) return false; a++; b++; } for (; a < na; a++) if (!page_at (a).is_empty ()) { return false; } for (; b < nb; b++) if (!other.page_at (b).is_empty ()) { return false; } return true; } bool is_subset (const hb_bit_set_t &larger_set) const { if (has_population () && larger_set.has_population () && population != larger_set.population) return false; uint32_t spi = 0; for (uint32_t lpi = 0; spi < page_map.length && lpi < larger_set.page_map.length; lpi++) { uint32_t spm = page_map[spi].major; uint32_t lpm = larger_set.page_map[lpi].major; auto sp = page_at (spi); auto lp = larger_set.page_at (lpi); if (spm < lpm && !sp.is_empty ()) return false; if (lpm < spm) continue; if (!sp.is_subset (lp)) return false; spi++; } while (spi < page_map.length) if (!page_at (spi++).is_empty ()) return false; return true; } private: bool allocate_compact_workspace (hb_vector_t& workspace) { if (unlikely (!workspace.resize (pages.length))) { successful = false; return false; } return true; } /* * workspace should be a pre-sized vector allocated to hold at exactly pages.length * elements. */ void compact (hb_vector_t& workspace, unsigned int length) { assert(workspace.length == pages.length); hb_vector_t& old_index_to_page_map_index = workspace; hb_fill (old_index_to_page_map_index.writer(), 0xFFFFFFFF); for (unsigned i = 0; i < length; i++) old_index_to_page_map_index[page_map[i].index] = i; compact_pages (old_index_to_page_map_index); } void compact_pages (const hb_vector_t& old_index_to_page_map_index) { unsigned int write_index = 0; for (unsigned int i = 0; i < pages.length; i++) { if (old_index_to_page_map_index[i] == 0xFFFFFFFF) continue; if (write_index < i) pages[write_index] = pages[i]; page_map[old_index_to_page_map_index[i]].index = write_index; write_index++; } } public: void process_ (hb_bit_page_t::vector_t (*op) (const hb_bit_page_t::vector_t &, const hb_bit_page_t::vector_t &), bool passthru_left, bool passthru_right, const hb_bit_set_t &other) { if (unlikely (!successful)) return; dirty (); unsigned int na = pages.length; unsigned int nb = other.pages.length; unsigned int next_page = na; unsigned int count = 0, newCount = 0; unsigned int a = 0, b = 0; unsigned int write_index = 0; // Pre-allocate the workspace that compact() will need so we can bail on allocation failure // before attempting to rewrite the page map. hb_vector_t compact_workspace; if (!passthru_left && unlikely (!allocate_compact_workspace (compact_workspace))) return; for (; a < na && b < nb; ) { if (page_map[a].major == other.page_map[b].major) { if (!passthru_left) { // Move page_map entries that we're keeping from the left side set // to the front of the page_map vector. This isn't necessary if // passthru_left is set since no left side pages will be removed // in that case. if (write_index < a) page_map[write_index] = page_map[a]; write_index++; } count++; a++; b++; } else if (page_map[a].major < other.page_map[b].major) { if (passthru_left) count++; a++; } else { if (passthru_right) count++; b++; } } if (passthru_left) count += na - a; if (passthru_right) count += nb - b; if (!passthru_left) { na = write_index; next_page = write_index; compact (compact_workspace, write_index); } if (unlikely (!resize (count))) return; newCount = count; /* Process in-place backward. */ a = na; b = nb; for (; a && b; ) { if (page_map[a - 1].major == other.page_map[b - 1].major) { a--; b--; count--; page_map[count] = page_map[a]; page_at (count).v = op (page_at (a).v, other.page_at (b).v); } else if (page_map[a - 1].major > other.page_map[b - 1].major) { a--; if (passthru_left) { count--; page_map[count] = page_map[a]; } } else { b--; if (passthru_right) { count--; page_map[count].major = other.page_map[b].major; page_map[count].index = next_page++; page_at (count).v = other.page_at (b).v; } } } if (passthru_left) while (a) { a--; count--; page_map[count] = page_map [a]; } if (passthru_right) while (b) { b--; count--; page_map[count].major = other.page_map[b].major; page_map[count].index = next_page++; page_at (count).v = other.page_at (b).v; } assert (!count); resize (newCount); } template static hb_bit_page_t::vector_t op_ (const hb_bit_page_t::vector_t &a, const hb_bit_page_t::vector_t &b) { return Op{} (a, b); } template void process (const Op& op, const hb_bit_set_t &other) { process_ (op_, op (1, 0), op (0, 1), other); } void union_ (const hb_bit_set_t &other) { process (hb_bitwise_or, other); } void intersect (const hb_bit_set_t &other) { process (hb_bitwise_and, other); } void subtract (const hb_bit_set_t &other) { process (hb_bitwise_gt, other); } void symmetric_difference (const hb_bit_set_t &other) { process (hb_bitwise_xor, other); } bool next (hb_codepoint_t *codepoint) const { // TODO: this should be merged with prev() as both implementations // are very similar. if (unlikely (*codepoint == INVALID)) { *codepoint = get_min (); return *codepoint != INVALID; } const auto* page_map_array = page_map.arrayZ; unsigned int major = get_major (*codepoint); unsigned int i = last_page_lookup; if (unlikely (i >= page_map.length || page_map_array[i].major != major)) { page_map.bfind (major, &i, HB_NOT_FOUND_STORE_CLOSEST); if (i >= page_map.length) { *codepoint = INVALID; return false; } } const auto* pages_array = pages.arrayZ; const page_map_t ¤t = page_map_array[i]; if (likely (current.major == major)) { if (pages_array[current.index].next (codepoint)) { *codepoint += current.major * page_t::PAGE_BITS; last_page_lookup = i; return true; } i++; } for (; i < page_map.length; i++) { const page_map_t ¤t = page_map.arrayZ[i]; hb_codepoint_t m = pages_array[current.index].get_min (); if (m != INVALID) { *codepoint = current.major * page_t::PAGE_BITS + m; last_page_lookup = i; return true; } } last_page_lookup = 0; *codepoint = INVALID; return false; } bool previous (hb_codepoint_t *codepoint) const { if (unlikely (*codepoint == INVALID)) { *codepoint = get_max (); return *codepoint != INVALID; } page_map_t map = {get_major (*codepoint), 0}; unsigned int i; page_map.bfind (map, &i, HB_NOT_FOUND_STORE_CLOSEST); if (i < page_map.length && page_map[i].major == map.major) { if (pages[page_map[i].index].previous (codepoint)) { *codepoint += page_map[i].major * page_t::PAGE_BITS; return true; } } i--; for (; (int) i >= 0; i--) { hb_codepoint_t m = pages[page_map[i].index].get_max (); if (m != INVALID) { *codepoint = page_map[i].major * page_t::PAGE_BITS + m; return true; } } *codepoint = INVALID; return false; } 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; } /* TODO Speed up. */ *last = *first = i; while (next (&i) && i == *last + 1) (*last)++; return true; } bool previous_range (hb_codepoint_t *first, hb_codepoint_t *last) const { hb_codepoint_t i; i = *first; if (!previous (&i)) { *last = *first = INVALID; return false; } /* TODO Speed up. */ *last = *first = i; while (previous (&i) && i == *first - 1) (*first)--; return true; } unsigned int next_many (hb_codepoint_t codepoint, hb_codepoint_t *out, unsigned int size) const { // By default, start at the first bit of the first page of values. unsigned int start_page = 0; unsigned int start_page_value = 0; if (unlikely (codepoint != INVALID)) { const auto* page_map_array = page_map.arrayZ; unsigned int major = get_major (codepoint); unsigned int i = last_page_lookup; if (unlikely (i >= page_map.length || page_map_array[i].major != major)) { page_map.bfind (major, &i, HB_NOT_FOUND_STORE_CLOSEST); if (i >= page_map.length) return 0; // codepoint is greater than our max element. } start_page = i; start_page_value = page_remainder (codepoint + 1); if (unlikely (start_page_value == 0)) { // The export-after value was last in the page. Start on next page. start_page++; start_page_value = 0; } } unsigned int initial_size = size; for (unsigned int i = start_page; i < page_map.length && size; i++) { uint32_t base = major_start (page_map[i].major); unsigned int n = pages[page_map[i].index].write (base, start_page_value, out, size); out += n; size -= n; start_page_value = 0; } return initial_size - size; } unsigned int next_many_inverted (hb_codepoint_t codepoint, hb_codepoint_t *out, unsigned int size) const { unsigned int initial_size = size; // By default, start at the first bit of the first page of values. unsigned int start_page = 0; unsigned int start_page_value = 0; if (unlikely (codepoint != INVALID)) { const auto* page_map_array = page_map.arrayZ; unsigned int major = get_major (codepoint); unsigned int i = last_page_lookup; if (unlikely (i >= page_map.length || page_map_array[i].major != major)) { page_map.bfind(major, &i, HB_NOT_FOUND_STORE_CLOSEST); if (unlikely (i >= page_map.length)) { // codepoint is greater than our max element. while (++codepoint != INVALID && size) { *out++ = codepoint; size--; } return initial_size - size; } } start_page = i; start_page_value = page_remainder (codepoint + 1); if (unlikely (start_page_value == 0)) { // The export-after value was last in the page. Start on next page. start_page++; start_page_value = 0; } } hb_codepoint_t next_value = codepoint + 1; for (unsigned int i=start_page; i= 0; i--) { const auto& map = page_map[(unsigned) i]; const auto& page = pages[map.index]; if (!page.is_empty ()) return map.major * page_t::PAGE_BITS + page.get_max (); } return INVALID; } static constexpr hb_codepoint_t INVALID = page_t::INVALID; /* * Iterator implementation. */ struct iter_t : hb_iter_with_fallback_t { static constexpr bool is_sorted_iterator = true; iter_t (const hb_bit_set_t &s_ = Null (hb_bit_set_t), bool init = true) : s (&s_), v (INVALID), l(0) { if (init) { l = s->get_population () + 1; __next__ (); } } typedef hb_codepoint_t __item_t__; hb_codepoint_t __item__ () const { return v; } bool __more__ () const { return v != INVALID; } void __next__ () { s->next (&v); if (l) l--; } void __prev__ () { s->previous (&v); } unsigned __len__ () const { return l; } iter_t end () const { return iter_t (*s, false); } bool operator != (const iter_t& o) const { return s != o.s || v != o.v; } protected: const hb_bit_set_t *s; hb_codepoint_t v; unsigned l; }; iter_t iter () const { return iter_t (*this); } operator iter_t () const { return iter (); } protected: page_t *page_for (hb_codepoint_t g, bool insert = false) { unsigned major = get_major (g); /* The extra page_map length is necessary; can't just rely on vector here, * since the next check would be tricked because a null page also has * major==0, which we can't distinguish from an actualy major==0 page... */ unsigned i = last_page_lookup; if (likely (i < page_map.length)) { auto &cached_page = page_map.arrayZ[i]; if (cached_page.major == major) return &pages[cached_page.index]; } page_map_t map = {major, pages.length}; if (!page_map.bfind (map, &i, HB_NOT_FOUND_STORE_CLOSEST)) { if (!insert) return nullptr; if (unlikely (!resize (pages.length + 1))) return nullptr; pages[map.index].init0 (); memmove (page_map + i + 1, page_map + i, (page_map.length - 1 - i) * page_map.item_size); page_map[i] = map; } last_page_lookup = i; return &pages[page_map[i].index]; } const page_t *page_for (hb_codepoint_t g) const { unsigned major = get_major (g); /* The extra page_map length is necessary; can't just rely on vector here, * since the next check would be tricked because a null page also has * major==0, which we can't distinguish from an actualy major==0 page... */ unsigned i = last_page_lookup; if (likely (i < page_map.length)) { auto &cached_page = page_map.arrayZ[i]; if (cached_page.major == major) return &pages[cached_page.index]; } page_map_t key = {major}; if (!page_map.bfind (key, &i)) return nullptr; last_page_lookup = i; return &pages[page_map[i].index]; } page_t &page_at (unsigned int i) { return pages[page_map[i].index]; } const page_t &page_at (unsigned int i) const { return pages[page_map[i].index]; } unsigned int get_major (hb_codepoint_t g) const { return g >> page_t::PAGE_BITS_LOG_2; } unsigned int page_remainder (hb_codepoint_t g) const { return g & page_t::PAGE_BITMASK; } hb_codepoint_t major_start (unsigned int major) const { return major << page_t::PAGE_BITS_LOG_2; } }; #endif /* HB_BIT_SET_HH */