src/hb-set-private.hh - third_party/harfbuzz - Git at Google

 /*
  * 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-set.h"
 #include "hb-object-private.hh"


 struct hb_set_digest_common_bits_t
 {
   ASSERT_POD ();

   typedef unsigned int mask_t;

   inline void init (void) {
     mask = ~0;
     value = (mask_t) -1;
   }

   inline void add (hb_codepoint_t g) {
     if (unlikely (value == (mask_t) -1)) {
       value = g;
       return;
     }

     mask ^= (g & mask) ^ value;
     value &= mask;
   }

   inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
     /* The negation here stands for ~(x-1). */
     mask &= -(1 << _hb_bit_storage (a ^ b));
     value &= mask;
   }

   inline bool may_have (hb_codepoint_t g) const {
     return (g & mask) == value;
   }

   private:
   mask_t mask;
   mask_t value;
 };

 struct hb_set_digest_lowest_bits_t
 {
   ASSERT_POD ();

   typedef unsigned long mask_t;

   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 - a >= sizeof (mask_t) * 8 - 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 & (sizeof (mask_t) * 8 - 1)); }
   mask_t mask;
 };

 struct hb_set_digest_t
 {
   ASSERT_POD ();

   inline void init (void) {
     digest1.init ();
     digest2.init ();
   }

   inline void add (hb_codepoint_t g) {
     digest1.add (g);
     digest2.add (g);
   }

   inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
     digest1.add_range (a, b);
     digest2.add_range (a, b);
   }

   inline bool may_have (hb_codepoint_t g) const {
     return digest1.may_have (g) && digest2.may_have (g);
   }

   private:
   hb_set_digest_common_bits_t digest1;
   hb_set_digest_lowest_bits_t digest2;
 };


 /* TODO Make this faster and memmory efficient. */

 struct hb_set_t
 {
   hb_object_header_t header;
   ASSERT_POD ();

   inline void init (void) {
     header.init ();
     clear ();
   }
   inline void fini (void) {
   }
   inline void clear (void) {
     memset (elts, 0, sizeof elts);
   }
   inline bool 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 (g == SENTINEL)) return;
     if (unlikely (g > MAX_G)) return;
     elt (g) |= mask (g);
   }
   inline void add_range (hb_codepoint_t a, hb_codepoint_t b)
   {
     for (unsigned int i = a; i < b + 1; i++)
       add (i);
   }
   inline void del (hb_codepoint_t g)
   {
     if (unlikely (g > MAX_G)) return;
     elt (g) &= ~mask (g);
   }
   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 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)
   {
     for (unsigned int i = 0; i < ELTS; i++)
       elts[i] = other->elts[i];
   }
   inline void union_ (const hb_set_t *other)
   {
     for (unsigned int i = 0; i < ELTS; i++)
       elts[i] |= other->elts[i];
   }
   inline void intersect (const hb_set_t *other)
   {
     for (unsigned int i = 0; i < ELTS; i++)
       elts[i] &= other->elts[i];
   }
   inline void subtract (const hb_set_t *other)
   {
     for (unsigned int i = 0; i < ELTS; i++)
       elts[i] &= ~other->elts[i];
   }
   inline void symmetric_difference (const hb_set_t *other)
   {
     for (unsigned int i = 0; i < ELTS; i++)
       elts[i] ^= other->elts[i];
   }
   inline bool next (hb_codepoint_t *codepoint)
   {
     if (unlikely (*codepoint == SENTINEL)) {
       hb_codepoint_t i = get_min ();
       if (i != SENTINEL) {
         *codepoint = i;
 	return true;
       } else
         return false;
     }
     for (hb_codepoint_t i = *codepoint + 1; i < MAX_G + 1; i++)
       if (has (i)) {
         *codepoint = i;
 	return true;
       }
     return false;
   }
   inline hb_codepoint_t get_min (void) const
   {
     for (unsigned int i = 0; i < ELTS; i++)
       if (elts[i])
 	for (unsigned int j = 0; i < BITS; j++)
 	  if (elts[i] & (1 << j))
 	    return i * BITS + j;
     return SENTINEL;
   }
   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 SENTINEL;
   }

   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 SENTINEL = (hb_codepoint_t) -1;

   elt_t &elt (hb_codepoint_t g) { return elts[g >> SHIFT]; }
   elt_t 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);
 };


 #endif /* HB_SET_PRIVATE_HH */
	/*
	* 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-set.h"
	#include "hb-object-private.hh"


	struct hb_set_digest_common_bits_t
	{
	ASSERT_POD ();

	typedef unsigned int mask_t;

	inline void init (void) {
	mask = ~0;
	value = (mask_t) -1;
	}

	inline void add (hb_codepoint_t g) {
	if (unlikely (value == (mask_t) -1)) {
	value = g;
	return;
	}

	mask ^= (g & mask) ^ value;
	value &= mask;
	}

	inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
	/* The negation here stands for ~(x-1). */
	mask &= -(1 << _hb_bit_storage (a ^ b));
	value &= mask;
	}

	inline bool may_have (hb_codepoint_t g) const {
	return (g & mask) == value;
	}

	private:
	mask_t mask;
	mask_t value;
	};

	struct hb_set_digest_lowest_bits_t
	{
	ASSERT_POD ();

	typedef unsigned long mask_t;

	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 - a >= sizeof (mask_t) * 8 - 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 & (sizeof (mask_t) * 8 - 1)); }
	mask_t mask;
	};

	struct hb_set_digest_t
	{
	ASSERT_POD ();

	inline void init (void) {
	digest1.init ();
	digest2.init ();
	}

	inline void add (hb_codepoint_t g) {
	digest1.add (g);
	digest2.add (g);
	}

	inline void add_range (hb_codepoint_t a, hb_codepoint_t b) {
	digest1.add_range (a, b);
	digest2.add_range (a, b);
	}

	inline bool may_have (hb_codepoint_t g) const {
	return digest1.may_have (g) && digest2.may_have (g);
	}

	private:
	hb_set_digest_common_bits_t digest1;
	hb_set_digest_lowest_bits_t digest2;
	};


	/* TODO Make this faster and memmory efficient. */

	struct hb_set_t
	{
	hb_object_header_t header;
	ASSERT_POD ();

	inline void init (void) {
	header.init ();
	clear ();
	}
	inline void fini (void) {
	}
	inline void clear (void) {
	memset (elts, 0, sizeof elts);
	}
	inline bool 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 (g == SENTINEL)) return;
	if (unlikely (g > MAX_G)) return;
	elt (g) \|= mask (g);
	}
	inline void add_range (hb_codepoint_t a, hb_codepoint_t b)
	{
	for (unsigned int i = a; i < b + 1; i++)
	add (i);
	}
	inline void del (hb_codepoint_t g)
	{
	if (unlikely (g > MAX_G)) return;
	elt (g) &= ~mask (g);
	}
	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 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)
	{
	for (unsigned int i = 0; i < ELTS; i++)
	elts[i] = other->elts[i];
	}
	inline void union_ (const hb_set_t *other)
	{
	for (unsigned int i = 0; i < ELTS; i++)
	elts[i] \|= other->elts[i];
	}
	inline void intersect (const hb_set_t *other)
	{
	for (unsigned int i = 0; i < ELTS; i++)
	elts[i] &= other->elts[i];
	}
	inline void subtract (const hb_set_t *other)
	{
	for (unsigned int i = 0; i < ELTS; i++)
	elts[i] &= ~other->elts[i];
	}
	inline void symmetric_difference (const hb_set_t *other)
	{
	for (unsigned int i = 0; i < ELTS; i++)
	elts[i] ^= other->elts[i];
	}
	inline bool next (hb_codepoint_t *codepoint)
	{
	if (unlikely (*codepoint == SENTINEL)) {
	hb_codepoint_t i = get_min ();
	if (i != SENTINEL) {
	*codepoint = i;
	return true;
	} else
	return false;
	}
	for (hb_codepoint_t i = *codepoint + 1; i < MAX_G + 1; i++)
	if (has (i)) {
	*codepoint = i;
	return true;
	}
	return false;
	}
	inline hb_codepoint_t get_min (void) const
	{
	for (unsigned int i = 0; i < ELTS; i++)
	if (elts[i])
	for (unsigned int j = 0; i < BITS; j++)
	if (elts[i] & (1 << j))
	return i * BITS + j;
	return SENTINEL;
	}
	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 SENTINEL;
	}

	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 SENTINEL = (hb_codepoint_t) -1;

	elt_t &elt (hb_codepoint_t g) { return elts[g >> SHIFT]; }
	elt_t 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);
	};



	#endif /* HB_SET_PRIVATE_HH */