tor-browser

hb-bimap.hh (5411B)

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/*
* Copyright © 2019 Adobe 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.
*
* Adobe Author(s): Michiharu Ariza
*/

#ifndef HB_BIMAP_HH
#define HB_BIMAP_HH

#include "hb.hh"
#include "hb-map.hh"

/* Bi-directional map */
struct hb_bimap_t
{
 void reset ()
 {
   forw_map.reset ();
   back_map.reset ();
 }

 void alloc (unsigned pop)
 {
   forw_map.alloc (pop);
   back_map.alloc (pop);
 }

 bool in_error () const { return forw_map.in_error () || back_map.in_error (); }

 void set (hb_codepoint_t lhs, hb_codepoint_t rhs)
 {
   if (in_error ()) return;
   if (unlikely (lhs == HB_MAP_VALUE_INVALID)) return;
   if (unlikely (rhs == HB_MAP_VALUE_INVALID)) { del (lhs); return; }

   forw_map.set (lhs, rhs);
   if (unlikely (in_error ())) return;

   back_map.set (rhs, lhs);
   if (unlikely (in_error ())) forw_map.del (lhs);
 }

 hb_codepoint_t get (hb_codepoint_t lhs) const { return forw_map.get (lhs); }
 hb_codepoint_t backward (hb_codepoint_t rhs) const { return back_map.get (rhs); }

 hb_codepoint_t operator [] (hb_codepoint_t lhs) const { return get (lhs); }
 bool has (hb_codepoint_t lhs) const { return forw_map.has (lhs); }


 void del (hb_codepoint_t lhs)
 {
   back_map.del (get (lhs));
   forw_map.del (lhs);
 }

 void clear ()
 {
   forw_map.clear ();
   back_map.clear ();
 }

 bool is_empty () const { return forw_map.is_empty (); }

 unsigned int get_population () const { return forw_map.get_population (); }

 protected:
 hb_map_t  forw_map;
 hb_map_t  back_map;

 public:
 auto keys () const HB_AUTO_RETURN (+ forw_map.keys())
 auto values () const HB_AUTO_RETURN (+ forw_map.values())
 auto iter () const HB_AUTO_RETURN (+ forw_map.iter())
};

/* Incremental bimap: only lhs is given, rhs is incrementally assigned */
struct hb_inc_bimap_t
{
 bool in_error () const { return forw_map.in_error () || back_map.in_error (); }

 unsigned int get_population () const { return forw_map.get_population (); }

 void reset ()
 {
   forw_map.reset ();
   back_map.reset ();
 }

 void alloc (unsigned pop)
 {
   forw_map.alloc (pop);
   back_map.alloc (pop);
 }

 void clear ()
 {
   forw_map.clear ();
   back_map.resize (0);
 }

 /* Add a mapping from lhs to rhs with a unique value if lhs is unknown.
  * Return the rhs value as the result.
  */
 hb_codepoint_t add (hb_codepoint_t lhs)
 {
   hb_codepoint_t  rhs = forw_map[lhs];
   if (rhs == HB_MAP_VALUE_INVALID)
   {
     rhs = back_map.length;
     forw_map.set (lhs, rhs);
     back_map.push (lhs);
   }
   return rhs;
 }

 hb_codepoint_t skip ()
 {
   hb_codepoint_t start = back_map.length;
   back_map.push (HB_MAP_VALUE_INVALID);
   return start;
 }

 hb_codepoint_t skip (unsigned count)
 {
   hb_codepoint_t start = back_map.length;
   back_map.alloc (back_map.length + count);
   for (unsigned i = 0; i < count; i++)
     back_map.push (HB_MAP_VALUE_INVALID);
   return start;
 }

 hb_codepoint_t get_next_value () const
 { return back_map.length; }

 void add_set (const hb_set_t *set)
 {
   for (auto i : *set) add (i);
 }

 /* Create an identity map. */
 bool identity (unsigned int size)
 {
   clear ();
   for (hb_codepoint_t i = 0; i < size; i++) add (i);
   return !in_error ();
 }

 protected:
 static int cmp_id (const void* a, const void* b)
 { return (int)*(const hb_codepoint_t *)a - (int)*(const hb_codepoint_t *)b; }

 public:
 /* Optional: after finished adding all mappings in a random order,
  * reassign rhs to lhs so that they are in the same order. */
 void sort ()
 {
   hb_codepoint_t  count = get_population ();
   hb_vector_t <hb_codepoint_t> work;
   if (unlikely (!work.resize_dirty  (count))) return;

   for (hb_codepoint_t rhs = 0; rhs < count; rhs++)
     work.arrayZ[rhs] = back_map[rhs];

   work.qsort (cmp_id);

   clear ();
   for (hb_codepoint_t rhs = 0; rhs < count; rhs++)
     add (work.arrayZ[rhs]);
 }

 hb_codepoint_t get (hb_codepoint_t lhs) const { return forw_map.get (lhs); }
 hb_codepoint_t backward (hb_codepoint_t rhs) const { return back_map[rhs]; }

 hb_codepoint_t operator [] (hb_codepoint_t lhs) const { return get (lhs); }
 bool has (hb_codepoint_t lhs) const { return forw_map.has (lhs); }

 protected:
 hb_map_t forw_map;
 hb_vector_t<hb_codepoint_t> back_map;

 public:
 auto keys () const HB_AUTO_RETURN (+ back_map.iter())
};

#endif /* HB_BIMAP_HH */