tor-browser

hb-open-file.hh (15753B)

---

/*
* Copyright © 2007,2008,2009  Red Hat, Inc.
* 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.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/

#ifndef HB_OPEN_FILE_HH
#define HB_OPEN_FILE_HH

#include "hb-open-type.hh"
#include "hb-ot-head-table.hh"


namespace OT {

/*
*
* The OpenType Font File
*
*/


/*
* Organization of an OpenType Font
*/

struct OpenTypeFontFile;
struct OpenTypeOffsetTable;
struct TTCHeader;


typedef struct TableRecord
{
 int cmp (Tag t) const { return -t.cmp (tag); }

 HB_INTERNAL static int cmp (const void *pa, const void *pb)
 {
   const TableRecord *a = (const TableRecord *) pa;
   const TableRecord *b = (const TableRecord *) pb;
   return b->cmp (a->tag);
 }

 bool sanitize (hb_sanitize_context_t *c) const
 {
   TRACE_SANITIZE (this);
   return_trace (c->check_struct (this));
 }

 Tag		tag;		/* 4-byte identifier. */
 CheckSum	checkSum;	/* CheckSum for this table. */
 Offset32	offset;		/* Offset from beginning of TrueType font
			 * file. */
 HBUINT32	length;		/* Length of this table. */
 public:
 DEFINE_SIZE_STATIC (16);
} OpenTypeTable;

typedef struct OpenTypeOffsetTable
{
 friend struct OpenTypeFontFile;

 unsigned int get_table_count () const { return tables.len; }
 const TableRecord& get_table (unsigned int i) const
 { return tables[i]; }
 unsigned int get_table_tags (unsigned int  start_offset,
		       unsigned int *table_count, /* IN/OUT */
		       hb_tag_t     *table_tags /* OUT */) const
 {
   if (table_count)
   {
     + tables.as_array ().sub_array (start_offset, table_count)
     | hb_map (&TableRecord::tag)
     | hb_sink (hb_array (table_tags, *table_count))
     ;
   }
   return tables.len;
 }
 bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
 {
   Tag t;
   t = tag;
   /* Use lfind for small fonts; there are fonts that have unsorted table entries;
    * those tend to work in other tools, so tolerate them.
    * https://github.com/harfbuzz/harfbuzz/issues/3065 */
   if (tables.len < 16)
     return tables.lfind (t, table_index, HB_NOT_FOUND_STORE, Index::NOT_FOUND_INDEX);
   else
     return tables.bfind (t, table_index, HB_NOT_FOUND_STORE, Index::NOT_FOUND_INDEX);
 }
 const TableRecord& get_table_by_tag (hb_tag_t tag) const
 {
   unsigned int table_index;
   find_table_index (tag, &table_index);
   return get_table (table_index);
 }

 public:

 template <typename Iterator,
    hb_requires ((hb_is_source_of<Iterator, hb_pair_t<hb_tag_t, hb_blob_t *>>::value))>
 bool serialize (hb_serialize_context_t *c,
	  hb_tag_t sfnt_tag,
	  Iterator it)
 {
   TRACE_SERIALIZE (this);
   /* Alloc 12 for the OTHeader. */
   if (unlikely (!c->extend_min (this))) return_trace (false);
   /* Write sfntVersion (bytes 0..3). */
   sfnt_version = sfnt_tag;
   /* Take space for numTables, searchRange, entrySelector, RangeShift
    * and the TableRecords themselves.  */
   unsigned num_items = hb_len (it);
   if (unlikely (!tables.serialize (c, num_items))) return_trace (false);

   const char *dir_end = (const char *) c->head;
   HBUINT32 *checksum_adjustment = nullptr;

   /* Write OffsetTables, alloc for and write actual table blobs. */
   unsigned i = 0;
   for (hb_pair_t<hb_tag_t, hb_blob_t*> entry : it)
   {
     hb_blob_t *blob = entry.second;
     unsigned len = blob->length;

     /* Allocate room for the table and copy it. */
     char *start = (char *) c->allocate_size<void> (len, false);
     if (unlikely (!start)) return false;

     TableRecord &rec = tables.arrayZ[i];
     rec.tag = entry.first;
     rec.length = len;
     rec.offset = 0;
     if (unlikely (!c->check_assign (rec.offset,
			      (unsigned) ((char *) start - (char *) this),
			      HB_SERIALIZE_ERROR_OFFSET_OVERFLOW)))
       return_trace (false);

     if (likely (len))
hb_memcpy (start, blob->data, len);

     /* 4-byte alignment. */
     c->align (4);
     const char *end = (const char *) c->head;

     if (entry.first == HB_OT_TAG_head &&
  (unsigned) (end - start) >= head::static_size)
     {
head *h = (head *) start;
checksum_adjustment = &h->checkSumAdjustment;
*checksum_adjustment = 0;
     }

     rec.checkSum.set_for_data (start, end - start);
     i++;
   }

   tables.qsort ();

   if (checksum_adjustment)
   {
     CheckSum checksum;

     /* The following line is a slower version of the following block. */
     //checksum.set_for_data (this, (const char *) c->head - (const char *) this);
     checksum.set_for_data (this, dir_end - (const char *) this);
     for (unsigned int i = 0; i < num_items; i++)
     {
TableRecord &rec = tables.arrayZ[i];
checksum = checksum + rec.checkSum;
     }

     *checksum_adjustment = 0xB1B0AFBAu - checksum;
   }

   return_trace (true);
 }

 bool sanitize (hb_sanitize_context_t *c) const
 {
   TRACE_SANITIZE (this);
   return_trace (c->check_struct (this) && tables.sanitize (c));
 }

 protected:
 Tag		sfnt_version;	/* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
 BinSearchArrayOf<TableRecord>
	tables;
 public:
 DEFINE_SIZE_ARRAY (12, tables);
} OpenTypeFontFace;


/*
* TrueType Collections
*/

struct TTCHeaderVersion1
{
 friend struct TTCHeader;

 unsigned int get_face_count () const { return table.len; }
 const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }

 bool sanitize (hb_sanitize_context_t *c) const
 {
   TRACE_SANITIZE (this);
   return_trace (table.sanitize (c, this));
 }

 protected:
 Tag		ttcTag;		/* TrueType Collection ID string: 'ttcf' */
 FixedVersion<>version;	/* Version of the TTC Header (1.0),
			 * 0x00010000u */
 Array32Of<Offset32To<OpenTypeOffsetTable>>
	table;		/* Array of offsets to the OffsetTable for each font
			 * from the beginning of the file */
 public:
 DEFINE_SIZE_ARRAY (12, table);
};

struct TTCHeader
{
 friend struct OpenTypeFontFile;

 private:

 unsigned int get_face_count () const
 {
   switch (u.header.version.major) {
   case 2: /* version 2 is compatible with version 1 */
   case 1: hb_barrier (); return u.version1.get_face_count ();
   default:return 0;
   }
 }
 const OpenTypeFontFace& get_face (unsigned int i) const
 {
   switch (u.header.version.major) {
   case 2: /* version 2 is compatible with version 1 */
   case 1: hb_barrier (); return u.version1.get_face (i);
   default:return Null (OpenTypeFontFace);
   }
 }

 bool sanitize (hb_sanitize_context_t *c) const
 {
   TRACE_SANITIZE (this);
   if (unlikely (!u.header.version.sanitize (c))) return_trace (false);
   hb_barrier ();
   switch (u.header.version.major) {
   case 2: /* version 2 is compatible with version 1 */
   case 1: hb_barrier (); return_trace (u.version1.sanitize (c));
   default:return_trace (true);
   }
 }

 protected:
 union {
 struct {
 Tag		ttcTag;		/* TrueType Collection ID string: 'ttcf' */
 FixedVersion<>version;	/* Version of the TTC Header (1.0 or 2.0),
			 * 0x00010000u or 0x00020000u */
 }			header;
 TTCHeaderVersion1	version1;
 } u;
};

/*
* Mac Resource Fork
*
* http://mirror.informatimago.com/next/developer.apple.com/documentation/mac/MoreToolbox/MoreToolbox-99.html
*/

struct ResourceRecord
{
 const OpenTypeFontFace & get_face (const void *data_base) const
 { return * reinterpret_cast<const OpenTypeFontFace *> ((data_base+offset).arrayZ); }

 bool sanitize (hb_sanitize_context_t *c,
	 const void *data_base) const
 {
   TRACE_SANITIZE (this);
   return_trace (c->check_struct (this) &&
	  offset.sanitize (c, data_base) &&
	  hb_barrier () &&
	  get_face (data_base).sanitize (c));
 }

 protected:
 HBUINT16	id;		/* Resource ID. */
 HBINT16	nameOffset;	/* Offset from beginning of resource name list
			 * to resource name, -1 means there is none. */
 HBUINT8	attrs;		/* Resource attributes */
 NNOffset24To<Array32Of<HBUINT8>>
	offset;		/* Offset from beginning of data block to
			 * data for this resource */
 HBUINT32	reserved;	/* Reserved for handle to resource */
 public:
 DEFINE_SIZE_STATIC (12);
};

#define HB_TAG_sfnt HB_TAG ('s','f','n','t')

struct ResourceTypeRecord
{
 unsigned int get_resource_count () const
 { return tag == HB_TAG_sfnt ? resCountM1 + 1 : 0; }

 bool is_sfnt () const { return tag == HB_TAG_sfnt; }

 const ResourceRecord& get_resource_record (unsigned int i,
				     const void *type_base) const
 { return (type_base+resourcesZ).as_array (get_resource_count ())[i]; }

 bool sanitize (hb_sanitize_context_t *c,
	 const void *type_base,
	 const void *data_base) const
 {
   TRACE_SANITIZE (this);
   return_trace (c->check_struct (this) &&
	  hb_barrier () &&
	  resourcesZ.sanitize (c, type_base,
			       get_resource_count (),
			       data_base));
 }

 protected:
 Tag		tag;		/* Resource type. */
 HBUINT16	resCountM1;	/* Number of resources minus 1. */
 NNOffset16To<UnsizedArrayOf<ResourceRecord>>
	resourcesZ;	/* Offset from beginning of resource type list
			 * to reference item list for this type. */
 public:
 DEFINE_SIZE_STATIC (8);
};

struct ResourceMap
{
 unsigned int get_face_count () const
 {
   unsigned int count = get_type_count ();
   for (unsigned int i = 0; i < count; i++)
   {
     const ResourceTypeRecord& type = get_type_record (i);
     if (type.is_sfnt ())
return type.get_resource_count ();
   }
   return 0;
 }

 const OpenTypeFontFace& get_face (unsigned int idx,
			    const void *data_base) const
 {
   unsigned int count = get_type_count ();
   for (unsigned int i = 0; i < count; i++)
   {
     const ResourceTypeRecord& type = get_type_record (i);
     /* The check for idx < count is here because ResourceRecord is NOT null-safe.
      * Because an offset of 0 there does NOT mean null. */
     if (type.is_sfnt () && idx < type.get_resource_count ())
return type.get_resource_record (idx, &(this+typeList)).get_face (data_base);
   }
   return Null (OpenTypeFontFace);
 }

 bool sanitize (hb_sanitize_context_t *c, const void *data_base) const
 {
   TRACE_SANITIZE (this);
   return_trace (c->check_struct (this) &&
	  hb_barrier () &&
	  typeList.sanitize (c, this,
			     &(this+typeList),
			     data_base));
 }

 private:
 unsigned int get_type_count () const { return (this+typeList).lenM1 + 1; }

 const ResourceTypeRecord& get_type_record (unsigned int i) const
 { return (this+typeList)[i]; }

 protected:
 HBUINT8	reserved0[16];	/* Reserved for copy of resource header */
 HBUINT32	reserved1;	/* Reserved for handle to next resource map */
 HBUINT16	resreved2;	/* Reserved for file reference number */
 HBUINT16	attrs;		/* Resource fork attribute */
 NNOffset16To<ArrayOfM1<ResourceTypeRecord>>
	typeList;	/* Offset from beginning of map to
			 * resource type list */
 Offset16	nameList;	/* Offset from beginning of map to
			 * resource name list */
 public:
 DEFINE_SIZE_STATIC (28);
};

struct ResourceForkHeader
{
 unsigned int get_face_count () const
 { return (this+map).get_face_count (); }

 const OpenTypeFontFace& get_face (unsigned int idx,
			    unsigned int *base_offset = nullptr) const
 {
   const OpenTypeFontFace &face = (this+map).get_face (idx, &(this+data));
   if (base_offset)
     *base_offset = (const char *) &face - (const char *) this;
   return face;
 }

 bool sanitize (hb_sanitize_context_t *c) const
 {
   TRACE_SANITIZE (this);
   return_trace (c->check_struct (this) &&
	  hb_barrier () &&
	  data.sanitize (c, this, dataLen) &&
	  map.sanitize (c, this, &(this+data)));
 }

 protected:
 NNOffset32To<UnsizedArrayOf<HBUINT8>>
	data;		/* Offset from beginning of resource fork
			 * to resource data */
 NNOffset32To<ResourceMap >
	map;		/* Offset from beginning of resource fork
			 * to resource map */
 HBUINT32	dataLen;	/* Length of resource data */
 HBUINT32	mapLen;		/* Length of resource map */
 public:
 DEFINE_SIZE_STATIC (16);
};

/*
* OpenType Font File
*/

struct OpenTypeFontFile
{
 enum {
   CFFTag		= HB_TAG ('O','T','T','O'), /* OpenType with Postscript outlines */
   TrueTypeTag		= HB_TAG ( 0 , 1 , 0 , 0 ), /* OpenType with TrueType outlines */
   TTCTag		= HB_TAG ('t','t','c','f'), /* TrueType Collection */
   DFontTag		= HB_TAG ( 0 , 0 , 1 , 0 ), /* DFont Mac Resource Fork */
   TrueTag		= HB_TAG ('t','r','u','e'), /* Obsolete Apple TrueType */
   Typ1Tag		= HB_TAG ('t','y','p','1')  /* Obsolete Apple Type1 font in SFNT container */
 };

 hb_tag_t get_tag () const { return u.tag.v; }

 unsigned int get_face_count () const
 {
   switch (u.tag.v) {
   case CFFTag:	/* All the non-collection tags */
   case TrueTag:
   case Typ1Tag:
   case TrueTypeTag:	return 1;
   case TTCTag:	return u.ttcHeader.get_face_count ();
   case DFontTag:	return u.rfHeader.get_face_count ();
   default:		return 0;
   }
 }
 const OpenTypeFontFace& get_face (unsigned int i, unsigned int *base_offset = nullptr) const
 {
   if (base_offset)
     *base_offset = 0;
   switch (u.tag.v) {
   /* Note: for non-collection SFNT data we ignore index.  This is because
    * Apple dfont container is a container of SFNT's.  So each SFNT is a
    * non-TTC, but the index is more than zero. */
   case CFFTag:	/* All the non-collection tags */
   case TrueTag:
   case Typ1Tag:
   case TrueTypeTag:	return u.fontFace;
   case TTCTag:	return u.ttcHeader.get_face (i);
   case DFontTag:	return u.rfHeader.get_face (i, base_offset);
   default:		return Null (OpenTypeFontFace);
   }
 }

 template <typename Iterator,
    hb_requires ((hb_is_source_of<Iterator, hb_pair_t<hb_tag_t, hb_blob_t *>>::value))>
 bool serialize_single (hb_serialize_context_t *c,
		 hb_tag_t sfnt_tag,
		 Iterator items)
 {
   TRACE_SERIALIZE (this);
   assert (sfnt_tag != TTCTag);
   if (unlikely (!c->extend_min (this))) return_trace (false);
   return_trace (u.fontFace.serialize (c, sfnt_tag, items));
 }

 bool sanitize (hb_sanitize_context_t *c) const
 {
   TRACE_SANITIZE (this);
   if (unlikely (!u.tag.v.sanitize (c))) return_trace (false);
   hb_barrier ();
   switch (u.tag.v) {
   case CFFTag:	/* All the non-collection tags */
   case TrueTag:
   case Typ1Tag:
   case TrueTypeTag:	return_trace (u.fontFace.sanitize (c));
   case TTCTag:	return_trace (u.ttcHeader.sanitize (c));
   case DFontTag:	return_trace (u.rfHeader.sanitize (c));
   default:		return_trace (true);
   }
 }

 protected:
 union {
 struct { Tag v; }	tag;		/* 4-byte identifier. */
 OpenTypeFontFace	fontFace;
 TTCHeader		ttcHeader;
 ResourceForkHeader	rfHeader;
 } u;
 public:
 DEFINE_SIZE_UNION (4, tag.v);
};


} /* namespace OT */


#endif /* HB_OPEN_FILE_HH */