/*
* Copyright © 2012,2017 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_HH
#define HB_SET_HH
#include "hb.hh"
/*
* hb_set_t
*/
/* TODO Keep a free-list so we can free pages that are completely zeroed. At that
* point maybe also use a sentinel value for "all-1" pages? */
struct hb_set_t
{
HB_NO_COPY_ASSIGN (hb_set_t);
hb_set_t () { init (); }
~hb_set_t () { fini (); }
struct page_map_t
{
int cmp (const page_map_t &o) const { return (int) o.major - (int) major; }
uint32_t major;
uint32_t index;
};
struct page_t
{
void init0 () { v.clear (); }
void init1 () { v.clear (0xFF); }
unsigned int len () const
{ return ARRAY_LENGTH_CONST (v); }
bool is_empty () const
{
for (unsigned int i = 0; i < len (); i++)
if (v[i])
return false;
return true;
}
void add (hb_codepoint_t g) { elt (g) |= mask (g); }
void del (hb_codepoint_t g) { elt (g) &= ~mask (g); }
bool has (hb_codepoint_t g) const { return !!(elt (g) & mask (g)); }
void add_range (hb_codepoint_t a, hb_codepoint_t b)
{
elt_t *la = &elt (a);
elt_t *lb = &elt (b);
if (la == lb)
*la |= (mask (b) << 1) - mask(a);
else
{
*la |= ~(mask (a) - 1);
la++;
memset (la, 0xff, (char *) lb - (char *) la);
*lb |= ((mask (b) << 1) - 1);
}
}
bool is_equal (const page_t *other) const
{
return 0 == hb_memcmp (&v, &other->v, sizeof (v));
}
unsigned int get_population () const
{
unsigned int pop = 0;
for (unsigned int i = 0; i < len (); i++)
pop += hb_popcount (v[i]);
return pop;
}
bool next (hb_codepoint_t *codepoint) const
{
unsigned int m = (*codepoint + 1) & MASK;
if (!m)
{
*codepoint = INVALID;
return false;
}
unsigned int i = m / ELT_BITS;
unsigned int j = m & ELT_MASK;
const elt_t vv = v[i] & ~((elt_t (1) << j) - 1);
for (const elt_t *p = &vv; i < len (); p = &v[++i])
if (*p)
{
*codepoint = i * ELT_BITS + elt_get_min (*p);
return true;
}
*codepoint = INVALID;
return false;
}
bool previous (hb_codepoint_t *codepoint) const
{
unsigned int m = (*codepoint - 1) & MASK;
if (m == MASK)
{
*codepoint = INVALID;
return false;
}
unsigned int i = m / ELT_BITS;
unsigned int j = m & ELT_MASK;
const elt_t vv = v[i] & ((elt_t (1) << (j + 1)) - 1);
for (const elt_t *p = &vv; (int) i >= 0; p = &v[--i])
if (*p)
{
*codepoint = i * ELT_BITS + elt_get_max (*p);
return true;
}
*codepoint = INVALID;
return false;
}
hb_codepoint_t get_min () const
{
for (unsigned int i = 0; i < len (); i++)
if (v[i])
return i * ELT_BITS + elt_get_min (v[i]);
return INVALID;
}
hb_codepoint_t get_max () const
{
for (int i = len () - 1; i >= 0; i--)
if (v[i])
return i * ELT_BITS + elt_get_max (v[i]);
return 0;
}
typedef unsigned long long elt_t;
enum { PAGE_BITS = 512 };
static_assert ((PAGE_BITS & ((PAGE_BITS) - 1)) == 0, "");
static unsigned int elt_get_min (const elt_t &elt) { return hb_ctz (elt); }
static unsigned int elt_get_max (const elt_t &elt) { return hb_bit_storage (elt) - 1; }
typedef hb_vector_size_t<elt_t, PAGE_BITS / 8> vector_t;
enum { ELT_BITS = sizeof (elt_t) * 8 };
enum { ELT_MASK = ELT_BITS - 1 };
enum { BITS = sizeof (vector_t) * 8 };
enum { MASK = BITS - 1 };
static_assert ((unsigned) PAGE_BITS == (unsigned) BITS, "");
elt_t &elt (hb_codepoint_t g) { return v[(g & MASK) / ELT_BITS]; }
elt_t const &elt (hb_codepoint_t g) const { return v[(g & MASK) / ELT_BITS]; }
elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & ELT_MASK); }
vector_t v;
};
static_assert (page_t::PAGE_BITS == sizeof (page_t) * 8, "");
hb_object_header_t header;
bool successful; /* Allocations successful */
mutable unsigned int population;
hb_vector_t<page_map_t, 1> page_map;
hb_vector_t<page_t, 1> pages;
void init_shallow ()
{
successful = true;
population = 0;
page_map.init ();
pages.init ();
}
void init ()
{
hb_object_init (this);
init_shallow ();
}
void fini_shallow ()
{
population = 0;
page_map.fini ();
pages.fini ();
}
void fini ()
{
hb_object_fini (this);
fini_shallow ();
}
bool in_error () const { return !successful; }
bool resize (unsigned int count)
{
if (unlikely (!successful)) return false;
if (!pages.resize (count) || !page_map.resize (count))
{
pages.resize (page_map.len);
successful = false;
return false;
}
return true;
}
void clear ()
{
if (unlikely (hb_object_is_immutable (this)))
return;
successful = true;
population = 0;
page_map.resize (0);
pages.resize (0);
}
bool is_empty () const
{
unsigned int count = pages.len;
for (unsigned int i = 0; i < count; i++)
if (!pages[i].is_empty ())
return false;
return true;
}
void dirty () { population = (unsigned int) -1; }
void add (hb_codepoint_t g)
{
if (unlikely (!successful)) return;
if (unlikely (g == INVALID)) return;
dirty ();
page_t *page = page_for_insert (g); 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_insert (a); if (unlikely (!page)) return false;
page->add_range (a, b);
}
else
{
page_t *page = page_for_insert (a); 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_insert (major_start (m)); if (unlikely (!page)) return false;
page->init1 ();
}
page = page_for_insert (b); if (unlikely (!page)) return false;
page->add_range (major_start (mb), b);
}
return true;
}
template <typename T>
void add_array (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_insert (g); if (unlikely (!page)) return;
unsigned int start = major_start (m);
unsigned int end = major_start (m + 1);
do
{
page->add (g);
array = (const T *) ((const char *) array + stride);
count--;
}
while (count && (g = *array, start <= g && g < end));
}
}
/* Might return false if array looks unsorted.
* Used for faster rejection of corrupt data. */
template <typename T>
bool add_sorted_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
{
if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */
if (!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_insert (g); if (unlikely (!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;
page->add (g);
array = (const T *) ((const char *) array + stride);
count--;
}
while (count && (g = *array, g < end));
}
return true;
}
void del (hb_codepoint_t g)
{
/* TODO perform op even if !successful. */
if (unlikely (!successful)) return;
page_t *page = page_for (g);
if (!page)
return;
dirty ();
page->del (g);
}
void del_range (hb_codepoint_t a, hb_codepoint_t b)
{
/* TODO perform op even if !successful. */
/* TODO Optimize, like add_range(). */
if (unlikely (!successful)) return;
for (unsigned int i = a; i < b + 1; i++)
del (i);
}
bool has (hb_codepoint_t g) const
{
const page_t *page = page_for (g);
if (!page)
return false;
return page->has (g);
}
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_set_t *other)
{
if (unlikely (!successful)) return;
unsigned int count = other->pages.len;
if (!resize (count))
return;
population = other->population;
memcpy ((void *) pages, (const void *) other->pages, count * pages.item_size);
memcpy ((void *) page_map, (const void *) other->page_map, count * page_map.item_size);
}
bool is_equal (const hb_set_t *other) const
{
if (get_population () != other->get_population ())
return false;
unsigned int na = pages.len;
unsigned int nb = other->pages.len;
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_set_t *larger_set) const
{
if (get_population () > larger_set->get_population ())
return false;
/* TODO Optimize to use pages. */
hb_codepoint_t c = INVALID;
while (next (&c))
if (!larger_set->has (c))
return false;
return true;
}
template <class Op>
void process (const hb_set_t *other)
{
if (unlikely (!successful)) return;
dirty ();
unsigned int na = pages.len;
unsigned int nb = other->pages.len;
unsigned int next_page = na;
unsigned int count = 0, newCount = 0;
unsigned int a = 0, b = 0;
for (; a < na && b < nb; )
{
if (page_map[a].major == other->page_map[b].major)
{
count++;
a++;
b++;
}
else if (page_map[a].major < other->page_map[b].major)
{
if (Op::passthru_left)
count++;
a++;
}
else
{
if (Op::passthru_right)
count++;
b++;
}
}
if (Op::passthru_left)
count += na - a;
if (Op::passthru_right)
count += nb - b;
if (count > pages.len)
if (!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];
Op::process (page_at (count).v, page_at (a).v, other->page_at (b).v);
}
else if (page_map[a - 1].major > other->page_map[b - 1].major)
{
a--;
if (Op::passthru_left)
{
count--;
page_map[count] = page_map[a];
}
}
else
{
b--;
if (Op::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 (Op::passthru_left)
while (a)
{
a--;
count--;
page_map[count] = page_map [a];
}
if (Op::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);
if (pages.len > newCount)
resize (newCount);
}
void union_ (const hb_set_t *other)
{
process<HbOpOr> (other);
}
void intersect (const hb_set_t *other)
{
process<HbOpAnd> (other);
}
void subtract (const hb_set_t *other)
{
process<HbOpMinus> (other);
}
void symmetric_difference (const hb_set_t *other)
{
process<HbOpXor> (other);
}
bool next (hb_codepoint_t *codepoint) const
{
if (unlikely (*codepoint == INVALID)) {
*codepoint = get_min ();
return *codepoint != INVALID;
}
page_map_t map = {get_major (*codepoint), 0};
unsigned int i;
page_map.bfind (map, &i, HB_BFIND_NOT_FOUND_STORE_CLOSEST);
if (i < page_map.len && page_map[i].major == map.major)
{
if (pages[page_map[i].index].next (codepoint))
{
*codepoint += page_map[i].major * page_t::PAGE_BITS;
return true;
}
i++;
}
for (; i < page_map.len; i++)
{
hb_codepoint_t m = pages[page_map[i].index].get_min ();
if (m != INVALID)
{
*codepoint = page_map[i].major * page_t::PAGE_BITS + m;
return true;
}
}
*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_BFIND_NOT_FOUND_STORE_CLOSEST);
if (i < page_map.len && 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 get_population () const
{
if (population != (unsigned int) -1)
return population;
unsigned int pop = 0;
unsigned int count = pages.len;
for (unsigned int i = 0; i < count; i++)
pop += pages[i].get_population ();
population = pop;
return pop;
}
hb_codepoint_t get_min () const
{
unsigned int count = pages.len;
for (unsigned int i = 0; i < count; i++)
if (!page_at (i).is_empty ())
return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_min ();
return INVALID;
}
hb_codepoint_t get_max () const
{
unsigned int count = pages.len;
for (int i = count - 1; i >= 0; i++)
if (!page_at (i).is_empty ())
return page_map[(unsigned) i].major * page_t::PAGE_BITS + page_at (i).get_max ();
return INVALID;
}
static const hb_codepoint_t INVALID = HB_SET_VALUE_INVALID;
page_t *page_for_insert (hb_codepoint_t g)
{
page_map_t map = {get_major (g), pages.len};
unsigned int i;
if (!page_map.bfind (map, &i, HB_BFIND_NOT_FOUND_STORE_CLOSEST))
{
if (!resize (pages.len + 1))
return nullptr;
pages[map.index].init0 ();
memmove (page_map + i + 1,
page_map + i,
(page_map.len - 1 - i) * page_map.item_size);
page_map[i] = map;
}
return &pages[page_map[i].index];
}
page_t *page_for (hb_codepoint_t g)
{
page_map_t key = {get_major (g)};
const page_map_t *found = page_map.bsearch (key);
if (found)
return &pages[found->index];
return nullptr;
}
const page_t *page_for (hb_codepoint_t g) const
{
page_map_t key = {get_major (g)};
const page_map_t *found = page_map.bsearch (key);
if (found)
return &pages[found->index];
return nullptr;
}
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; }
hb_codepoint_t major_start (unsigned int major) const { return major * page_t::PAGE_BITS; }
};
#endif /* HB_SET_HH */