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      1 /*
      2  * Copyright  2012,2013  Google, Inc.
      3  *
      4  *  This is part of HarfBuzz, a text shaping library.
      5  *
      6  * Permission is hereby granted, without written agreement and without
      7  * license or royalty fees, to use, copy, modify, and distribute this
      8  * software and its documentation for any purpose, provided that the
      9  * above copyright notice and the following two paragraphs appear in
     10  * all copies of this software.
     11  *
     12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
     13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
     14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
     15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
     16  * DAMAGE.
     17  *
     18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
     19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
     20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
     21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
     22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
     23  *
     24  * Google Author(s): Behdad Esfahbod
     25  */
     26 
     27 #include "hb-buffer-private.hh"
     28 
     29 
     30 static const char *serialize_formats[] = {
     31   "text",
     32   "json",
     33   NULL
     34 };
     35 
     36 /**
     37  * hb_buffer_serialize_list_formats:
     38  *
     39  * Returns a list of supported buffer serialization formats.
     40  *
     41  * Return value: (transfer none):
     42  * A string array of buffer serialization formats. Should not be freed.
     43  *
     44  * Since: 0.9.7
     45  **/
     46 const char **
     47 hb_buffer_serialize_list_formats (void)
     48 {
     49   return serialize_formats;
     50 }
     51 
     52 /**
     53  * hb_buffer_serialize_format_from_string:
     54  * @str: (array length=len) (element-type uint8_t): a string to parse
     55  * @len: length of @str, or -1 if string is %NULL terminated
     56  *
     57  * Parses a string into an #hb_buffer_serialize_format_t. Does not check if
     58  * @str is a valid buffer serialization format, use
     59  * hb_buffer_serialize_list_formats() to get the list of supported formats.
     60  *
     61  * Return value:
     62  * The parsed #hb_buffer_serialize_format_t.
     63  *
     64  * Since: 0.9.7
     65  **/
     66 hb_buffer_serialize_format_t
     67 hb_buffer_serialize_format_from_string (const char *str, int len)
     68 {
     69   /* Upper-case it. */
     70   return (hb_buffer_serialize_format_t) (hb_tag_from_string (str, len) & ~0x20202020u);
     71 }
     72 
     73 /**
     74  * hb_buffer_serialize_format_to_string:
     75  * @format: an #hb_buffer_serialize_format_t to convert.
     76  *
     77  * Converts @format to the string corresponding it, or %NULL if it is not a valid
     78  * #hb_buffer_serialize_format_t.
     79  *
     80  * Return value: (transfer none):
     81  * A %NULL terminated string corresponding to @format. Should not be freed.
     82  *
     83  * Since: 0.9.7
     84  **/
     85 const char *
     86 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format)
     87 {
     88   switch (format)
     89   {
     90     case HB_BUFFER_SERIALIZE_FORMAT_TEXT:	return serialize_formats[0];
     91     case HB_BUFFER_SERIALIZE_FORMAT_JSON:	return serialize_formats[1];
     92     default:
     93     case HB_BUFFER_SERIALIZE_FORMAT_INVALID:	return NULL;
     94   }
     95 }
     96 
     97 static unsigned int
     98 _hb_buffer_serialize_glyphs_json (hb_buffer_t *buffer,
     99 				  unsigned int start,
    100 				  unsigned int end,
    101 				  char *buf,
    102 				  unsigned int buf_size,
    103 				  unsigned int *buf_consumed,
    104 				  hb_font_t *font,
    105 				  hb_buffer_serialize_flags_t flags)
    106 {
    107   hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, NULL);
    108   hb_glyph_position_t *pos = (flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS) ?
    109 			     NULL : hb_buffer_get_glyph_positions (buffer, NULL);
    110 
    111   *buf_consumed = 0;
    112   for (unsigned int i = start; i < end; i++)
    113   {
    114     char b[1024];
    115     char *p = b;
    116 
    117     /* In the following code, we know b is large enough that no overflow can happen. */
    118 
    119 #define APPEND(s) HB_STMT_START { strcpy (p, s); p += strlen (s); } HB_STMT_END
    120 
    121     if (i)
    122       *p++ = ',';
    123 
    124     *p++ = '{';
    125 
    126     APPEND ("\"g\":");
    127     if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES))
    128     {
    129       char g[128];
    130       hb_font_glyph_to_string (font, info[i].codepoint, g, sizeof (g));
    131       *p++ = '"';
    132       for (char *q = g; *q; q++) {
    133         if (*q == '"')
    134 	  *p++ = '\\';
    135 	*p++ = *q;
    136       }
    137       *p++ = '"';
    138     }
    139     else
    140       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));
    141 
    142     if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {
    143       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"cl\":%u", info[i].cluster));
    144     }
    145 
    146     if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS))
    147     {
    148       p += snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"dx\":%d,\"dy\":%d",
    149 		     pos[i].x_offset, pos[i].y_offset);
    150       p += snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"ax\":%d,\"ay\":%d",
    151 		     pos[i].x_advance, pos[i].y_advance);
    152     }
    153 
    154     if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS)
    155     {
    156       hb_glyph_extents_t extents;
    157       hb_font_get_glyph_extents(font, info[i].codepoint, &extents);
    158       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"xb\":%d,\"yb\":%d",
    159         extents.x_bearing, extents.y_bearing));
    160       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"w\":%d,\"h\":%d",
    161         extents.width, extents.height));
    162     }
    163 
    164     *p++ = '}';
    165 
    166     unsigned int l = p - b;
    167     if (buf_size > l)
    168     {
    169       memcpy (buf, b, l);
    170       buf += l;
    171       buf_size -= l;
    172       *buf_consumed += l;
    173       *buf = '\0';
    174     } else
    175       return i - start;
    176   }
    177 
    178   return end - start;
    179 }
    180 
    181 static unsigned int
    182 _hb_buffer_serialize_glyphs_text (hb_buffer_t *buffer,
    183 				  unsigned int start,
    184 				  unsigned int end,
    185 				  char *buf,
    186 				  unsigned int buf_size,
    187 				  unsigned int *buf_consumed,
    188 				  hb_font_t *font,
    189 				  hb_buffer_serialize_flags_t flags)
    190 {
    191   hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, NULL);
    192   hb_glyph_position_t *pos = (flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS) ?
    193 			     NULL : hb_buffer_get_glyph_positions (buffer, NULL);
    194 
    195   *buf_consumed = 0;
    196   for (unsigned int i = start; i < end; i++)
    197   {
    198     char b[1024];
    199     char *p = b;
    200 
    201     /* In the following code, we know b is large enough that no overflow can happen. */
    202 
    203     if (i)
    204       *p++ = '|';
    205 
    206     if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES))
    207     {
    208       hb_font_glyph_to_string (font, info[i].codepoint, p, 128);
    209       p += strlen (p);
    210     }
    211     else
    212       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));
    213 
    214     if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {
    215       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "=%u", info[i].cluster));
    216     }
    217 
    218     if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS))
    219     {
    220       if (pos[i].x_offset || pos[i].y_offset)
    221 	p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "@%d,%d", pos[i].x_offset, pos[i].y_offset));
    222 
    223       *p++ = '+';
    224       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%d", pos[i].x_advance));
    225       if (pos[i].y_advance)
    226 	p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",%d", pos[i].y_advance));
    227     }
    228 
    229     if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS)
    230     {
    231       hb_glyph_extents_t extents;
    232       hb_font_get_glyph_extents(font, info[i].codepoint, &extents);
    233       p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "<%d,%d,%d,%d>", extents.x_bearing, extents.y_bearing, extents.width, extents.height));
    234     }
    235 
    236     unsigned int l = p - b;
    237     if (buf_size > l)
    238     {
    239       memcpy (buf, b, l);
    240       buf += l;
    241       buf_size -= l;
    242       *buf_consumed += l;
    243       *buf = '\0';
    244     } else
    245       return i - start;
    246   }
    247 
    248   return end - start;
    249 }
    250 
    251 /**
    252  * hb_buffer_serialize_glyphs:
    253  * @buffer: an #hb_buffer_t buffer.
    254  * @start: the first item in @buffer to serialize.
    255  * @end: the last item in @buffer to serialize.
    256  * @buf: (out) (array length=buf_size) (element-type uint8_t): output string to
    257  *       write serialized buffer into.
    258  * @buf_size: the size of @buf.
    259  * @buf_consumed: (out) (allow-none): if not %NULL, will be set to the number of byes written into @buf.
    260  * @font: (allow-none): the #hb_font_t used to shape this buffer, needed to
    261  *        read glyph names and extents. If %NULL, and empty font will be used.
    262  * @format: the #hb_buffer_serialize_format_t to use for formatting the output.
    263  * @flags: the #hb_buffer_serialize_flags_t that control what glyph properties
    264  *         to serialize.
    265  *
    266  * Serializes @buffer into a textual representation of its glyph content,
    267  * useful for showing the contents of the buffer, for example during debugging.
    268  * There are currently two supported serialization formats:
    269  *
    270  * ## text
    271  * A human-readable, plain text format.
    272  * The serialized glyphs will look something like:
    273  *
    274  * ```
    275  * [uni0651=0@518,0+0|uni0628=0+1897]
    276  * ```
    277  * - The serialized glyphs are delimited with `[` and `]`.
    278  * - Glyphs are separated with `|`
    279  * - Each glyph starts with glyph name, or glyph index if
    280  *   #HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES flag is set. Then,
    281  *   - If #HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS is not set, `=` then #hb_glyph_info_t.cluster.
    282  *   - If #HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS is not set, the #hb_glyph_position_t in the format:
    283  *     - If both #hb_glyph_position_t.x_offset and #hb_glyph_position_t.y_offset are not 0, `@x_offset,y_offset`. Then,
    284  *     - `+x_advance`, then `,y_advance` if #hb_glyph_position_t.y_advance is not 0. Then,
    285  *   - If #HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS is set, the
    286  *     #hb_glyph_extents_t in the format
    287  *     `&lt;x_bearing,y_bearing,width,height&gt;`
    288  *
    289  * ## json
    290  * TODO.
    291  *
    292  * Return value:
    293  * The number of serialized items.
    294  *
    295  * Since: 0.9.7
    296  **/
    297 unsigned int
    298 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
    299 			    unsigned int start,
    300 			    unsigned int end,
    301 			    char *buf,
    302 			    unsigned int buf_size,
    303 			    unsigned int *buf_consumed,
    304 			    hb_font_t *font,
    305 			    hb_buffer_serialize_format_t format,
    306 			    hb_buffer_serialize_flags_t flags)
    307 {
    308   assert (start <= end && end <= buffer->len);
    309 
    310   unsigned int sconsumed;
    311   if (!buf_consumed)
    312     buf_consumed = &sconsumed;
    313   *buf_consumed = 0;
    314 
    315   assert ((!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID) ||
    316 	  buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);
    317 
    318   if (!buffer->have_positions)
    319     flags |= HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS;
    320 
    321   if (unlikely (start == end))
    322     return 0;
    323 
    324   if (!font)
    325     font = hb_font_get_empty ();
    326 
    327   switch (format)
    328   {
    329     case HB_BUFFER_SERIALIZE_FORMAT_TEXT:
    330       return _hb_buffer_serialize_glyphs_text (buffer, start, end,
    331 					       buf, buf_size, buf_consumed,
    332 					       font, flags);
    333 
    334     case HB_BUFFER_SERIALIZE_FORMAT_JSON:
    335       return _hb_buffer_serialize_glyphs_json (buffer, start, end,
    336 					       buf, buf_size, buf_consumed,
    337 					       font, flags);
    338 
    339     default:
    340     case HB_BUFFER_SERIALIZE_FORMAT_INVALID:
    341       return 0;
    342 
    343   }
    344 }
    345 
    346 
    347 static hb_bool_t
    348 parse_uint (const char *pp, const char *end, uint32_t *pv)
    349 {
    350   char buf[32];
    351   unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - pp));
    352   strncpy (buf, pp, len);
    353   buf[len] = '\0';
    354 
    355   char *p = buf;
    356   char *pend = p;
    357   uint32_t v;
    358 
    359   errno = 0;
    360   v = strtol (p, &pend, 10);
    361   if (errno || p == pend || pend - p != end - pp)
    362     return false;
    363 
    364   *pv = v;
    365   return true;
    366 }
    367 
    368 static hb_bool_t
    369 parse_int (const char *pp, const char *end, int32_t *pv)
    370 {
    371   char buf[32];
    372   unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - pp));
    373   strncpy (buf, pp, len);
    374   buf[len] = '\0';
    375 
    376   char *p = buf;
    377   char *pend = p;
    378   int32_t v;
    379 
    380   errno = 0;
    381   v = strtol (p, &pend, 10);
    382   if (errno || p == pend || pend - p != end - pp)
    383     return false;
    384 
    385   *pv = v;
    386   return true;
    387 }
    388 
    389 #include "hb-buffer-deserialize-json.hh"
    390 #include "hb-buffer-deserialize-text.hh"
    391 
    392 /**
    393  * hb_buffer_deserialize_glyphs:
    394  * @buffer: an #hb_buffer_t buffer.
    395  * @buf: (array length=buf_len):
    396  * @buf_len:
    397  * @end_ptr: (out):
    398  * @font:
    399  * @format:
    400  *
    401  *
    402  *
    403  * Return value:
    404  *
    405  * Since: 0.9.7
    406  **/
    407 hb_bool_t
    408 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
    409 			      const char *buf,
    410 			      int buf_len, /* -1 means nul-terminated */
    411 			      const char **end_ptr, /* May be NULL */
    412 			      hb_font_t *font, /* May be NULL */
    413 			      hb_buffer_serialize_format_t format)
    414 {
    415   const char *end;
    416   if (!end_ptr)
    417     end_ptr = &end;
    418   *end_ptr = buf;
    419 
    420   assert ((!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID) ||
    421 	  buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);
    422 
    423   if (buf_len == -1)
    424     buf_len = strlen (buf);
    425 
    426   if (!buf_len)
    427   {
    428     *end_ptr = buf;
    429     return false;
    430   }
    431 
    432   hb_buffer_set_content_type (buffer, HB_BUFFER_CONTENT_TYPE_GLYPHS);
    433 
    434   if (!font)
    435     font = hb_font_get_empty ();
    436 
    437   switch (format)
    438   {
    439     case HB_BUFFER_SERIALIZE_FORMAT_TEXT:
    440       return _hb_buffer_deserialize_glyphs_text (buffer,
    441 						 buf, buf_len, end_ptr,
    442 						 font);
    443 
    444     case HB_BUFFER_SERIALIZE_FORMAT_JSON:
    445       return _hb_buffer_deserialize_glyphs_json (buffer,
    446 						 buf, buf_len, end_ptr,
    447 						 font);
    448 
    449     default:
    450     case HB_BUFFER_SERIALIZE_FORMAT_INVALID:
    451       return false;
    452 
    453   }
    454 }
    455