hb-buffer-serialize.cc

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/*
 * Copyright © 2012,2013  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
 */
 
#include "hb.hh"
 
#ifndef HB_NO_BUFFER_SERIALIZE
 
#include "hb-buffer.hh"
 
 
static const char *serialize_formats[] = {
  "text",
  "json",
  nullptr
};
 
const char **
hb_buffer_serialize_list_formats ()
{
  return serialize_formats;
}
 
hb_buffer_serialize_format_t
hb_buffer_serialize_format_from_string (const char *str, int len)
{
  /* Upper-case it. */
  return (hb_buffer_serialize_format_t) (hb_tag_from_string (str, len) & ~0x20202020u);
}
 
const char *
hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format)
{
  switch ((unsigned) format)
  {
    case HB_BUFFER_SERIALIZE_FORMAT_TEXT: return serialize_formats[0];
    case HB_BUFFER_SERIALIZE_FORMAT_JSON: return serialize_formats[1];
    default:
    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:  return nullptr;
  }
}
 
static unsigned int
_hb_buffer_serialize_glyphs_json (hb_buffer_t *buffer,
                                  unsigned int start,
                                  unsigned int end,
                                  char *buf,
                                  unsigned int buf_size,
                                  unsigned int *buf_consumed,
                                  hb_font_t *font,
                                  hb_buffer_serialize_flags_t flags)
{
  hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, nullptr);
  hb_glyph_position_t *pos = (flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS) ?
                             nullptr : hb_buffer_get_glyph_positions (buffer, nullptr);
 
  *buf_consumed = 0;
  hb_position_t x = 0, y = 0;
  for (unsigned int i = start; i < end; i++)
  {
    char b[1024];
    char *p = b;
 
    /* In the following code, we know b is large enough that no overflow can happen. */
 
#define APPEND(s) HB_STMT_START { strcpy (p, s); p += strlen (s); } HB_STMT_END
 
    if (i)
      *p++ = ',';
    else
      *p++ = '[';
 
    *p++ = '{';
 
    APPEND ("\"g\":");
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES))
    {
      char g[128];
      hb_font_glyph_to_string (font, info[i].codepoint, g, sizeof (g));
      *p++ = '"';
      for (char *q = g; *q; q++)
      {
    if (unlikely (*q == '"' || *q == '\\'))
      *p++ = '\\';
    *p++ = *q;
      }
      *p++ = '"';
    }
    else
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"cl\":%u", info[i].cluster));
    }
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS))
    {
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"dx\":%d,\"dy\":%d",
           x+pos[i].x_offset, y+pos[i].y_offset));
      if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES))
        p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"ax\":%d,\"ay\":%d",
             pos[i].x_advance, pos[i].y_advance));
    }
 
    if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS)
    {
      if (info[i].mask & HB_GLYPH_FLAG_DEFINED)
        p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"fl\":%u", info[i].mask & HB_GLYPH_FLAG_DEFINED));
    }
 
    if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS)
    {
      hb_glyph_extents_t extents;
      hb_font_get_glyph_extents(font, info[i].codepoint, &extents);
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"xb\":%d,\"yb\":%d",
                                extents.x_bearing, extents.y_bearing));
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"w\":%d,\"h\":%d",
                                extents.width, extents.height));
    }
 
    *p++ = '}';
    if (i == end-1)
      *p++ = ']';
 
    unsigned int l = p - b;
    if (buf_size > l)
    {
      memcpy (buf, b, l);
      buf += l;
      buf_size -= l;
      *buf_consumed += l;
      *buf = '\0';
    } else
      return i - start;
 
    if (pos && (flags & HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES))
    {
      x += pos[i].x_advance;
      y += pos[i].y_advance;
    }
  }
 
  return end - start;
}
 
static unsigned int
_hb_buffer_serialize_unicode_json (hb_buffer_t *buffer,
          unsigned int start,
          unsigned int end,
          char *buf,
          unsigned int buf_size,
          unsigned int *buf_consumed,
          hb_buffer_serialize_flags_t flags)
{
  hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, nullptr);
 
  *buf_consumed = 0;
  for (unsigned int i = start; i < end; i++)
  {
    char b[1024];
    char *p = b;
 
    if (i)
      *p++ = ',';
    else
      *p++ = '[';
 
    *p++ = '{';
 
    APPEND ("\"u\":");
 
    p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"cl\":%u", info[i].cluster));
    }
 
    *p++ = '}';
 
    if (i == end-1)
      *p++ = ']';
 
    unsigned int l = p - b;
    if (buf_size > l)
    {
      memcpy (buf, b, l);
      buf += l;
      buf_size -= l;
      *buf_consumed += l;
      *buf = '\0';
    } else
      return i - start;
 
  }
 
  return end - start;
}
 
static unsigned int
_hb_buffer_serialize_glyphs_text (hb_buffer_t *buffer,
                                  unsigned int start,
                                  unsigned int end,
                                  char *buf,
                                  unsigned int buf_size,
                                  unsigned int *buf_consumed,
                                  hb_font_t *font,
                                  hb_buffer_serialize_flags_t flags)
{
  hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, nullptr);
  hb_glyph_position_t *pos = (flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS) ?
           nullptr : hb_buffer_get_glyph_positions (buffer, nullptr);
 
  *buf_consumed = 0;
  hb_position_t x = 0, y = 0;
  for (unsigned int i = start; i < end; i++)
  {
    char b[1024];
    char *p = b;
 
    /* In the following code, we know b is large enough that no overflow can happen. */
 
    if (i)
      *p++ = '|';
    else
      *p++ = '[';
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES))
    {
      /* TODO Escape delimiters we use. */
      hb_font_glyph_to_string (font, info[i].codepoint, p, 128);
      p += strlen (p);
    }
    else
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "=%u", info[i].cluster));
    }
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS))
    {
      if (x+pos[i].x_offset || y+pos[i].y_offset)
        p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "@%d,%d", x+pos[i].x_offset, y+pos[i].y_offset));
 
      if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES))
      {
        *p++ = '+';
        p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%d", pos[i].x_advance));
        if (pos[i].y_advance)
          p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",%d", pos[i].y_advance));
      }
    }
 
    if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS)
    {
      if (info[i].mask & HB_GLYPH_FLAG_DEFINED)
        p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "#%X", info[i].mask &HB_GLYPH_FLAG_DEFINED));
    }
 
    if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS)
    {
      hb_glyph_extents_t extents;
      hb_font_get_glyph_extents(font, info[i].codepoint, &extents);
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "<%d,%d,%d,%d>", extents.x_bearing, extents.y_bearing, extents.width, extents.height));
    }
 
    if (i == end-1) {
      *p++ = ']';
    }
 
    unsigned int l = p - b;
    if (buf_size > l)
    {
      memcpy (buf, b, l);
      buf += l;
      buf_size -= l;
      *buf_consumed += l;
      *buf = '\0';
    } else
      return i - start;
 
    if (pos && (flags & HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES))
    {
      x += pos[i].x_advance;
      y += pos[i].y_advance;
    }
  }
 
  return end - start;
}
 
 
static unsigned int
_hb_buffer_serialize_unicode_text (hb_buffer_t *buffer,
                                   unsigned int start,
                                   unsigned int end,
                                   char *buf,
                                   unsigned int buf_size,
                                   unsigned int *buf_consumed,
                                   hb_buffer_serialize_flags_t flags)
{
  hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, nullptr);
  *buf_consumed = 0;
  for (unsigned int i = start; i < end; i++)
  {
    char b[1024];
    char *p = b;
 
    if (i)
      *p++ = '|';
    else
      *p++ = '<';
 
    p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "U+%04X", info[i].codepoint));
 
    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {
      p += hb_max (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "=%u", info[i].cluster));
    }
 
    if (i == end-1)
      *p++ = '>';
 
    unsigned int l = p - b;
    if (buf_size > l)
    {
      memcpy (buf, b, l);
      buf += l;
      buf_size -= l;
      *buf_consumed += l;
      *buf = '\0';
    } else
      return i - start;
  }
  return end - start;
}
 
unsigned int
hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
                            unsigned int start,
                            unsigned int end,
                            char *buf,
                            unsigned int buf_size,
                            unsigned int *buf_consumed,
                            hb_font_t *font,
                            hb_buffer_serialize_format_t format,
                            hb_buffer_serialize_flags_t flags)
{
  end = hb_clamp (end, start, buffer->len);
  start = hb_min (start, end);
 
  unsigned int sconsumed;
  if (!buf_consumed)
    buf_consumed = &sconsumed;
  *buf_consumed = 0;
  if (buf_size)
    *buf = '\0';
 
  buffer->assert_glyphs ();
 
  if (!buffer->have_positions)
    flags |= HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS;
 
  if (unlikely (start == end))
    return 0;
 
  if (!font)
    font = hb_font_get_empty ();
 
  switch (format)
  {
    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:
      return _hb_buffer_serialize_glyphs_text (buffer, start, end,
                 buf, buf_size, buf_consumed,
                 font, flags);
 
    case HB_BUFFER_SERIALIZE_FORMAT_JSON:
      return _hb_buffer_serialize_glyphs_json (buffer, start, end,
                 buf, buf_size, buf_consumed,
                 font, flags);
 
    default:
    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:
      return 0;
 
  }
}
 
unsigned int
hb_buffer_serialize_unicode (hb_buffer_t *buffer,
                             unsigned int start,
                             unsigned int end,
                             char *buf,
                             unsigned int buf_size,
                             unsigned int *buf_consumed,
                             hb_buffer_serialize_format_t format,
                             hb_buffer_serialize_flags_t flags)
{
  end = hb_clamp (end, start, buffer->len);
  start = hb_min (start, end);
 
  unsigned int sconsumed;
  if (!buf_consumed)
    buf_consumed = &sconsumed;
  *buf_consumed = 0;
  if (buf_size)
    *buf = '\0';
 
  buffer->assert_unicode ();
 
  if (unlikely (start == end))
    return 0;
 
  switch (format)
  {
    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:
      return _hb_buffer_serialize_unicode_text (buffer, start, end,
                                                buf, buf_size, buf_consumed, flags);
 
    case HB_BUFFER_SERIALIZE_FORMAT_JSON:
      return _hb_buffer_serialize_unicode_json (buffer, start, end,
                                                buf, buf_size, buf_consumed, flags);
 
    default:
    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:
      return 0;
 
  }
}
 
static unsigned int
_hb_buffer_serialize_invalid (hb_buffer_t *buffer,
                              unsigned int start,
                              unsigned int end,
                              char *buf,
                              unsigned int buf_size,
                              unsigned int *buf_consumed,
                              hb_buffer_serialize_format_t format,
                              hb_buffer_serialize_flags_t flags)
{
  assert (!buffer->len);
 
  unsigned int sconsumed;
  if (!buf_consumed)
    buf_consumed = &sconsumed;
  if (buf_size < 3)
    return 0;
  if (format == HB_BUFFER_SERIALIZE_FORMAT_JSON) {
    *buf++ = '[';
    *buf++ = ']';
    *buf = '\0';
  } else if (format == HB_BUFFER_SERIALIZE_FORMAT_TEXT) {
    *buf++ = '!';
    *buf++ = '!';
    *buf = '\0';
  }
  *buf_consumed = 2;
  return 0;
}
 
unsigned int
hb_buffer_serialize (hb_buffer_t *buffer,
                     unsigned int start,
                     unsigned int end,
                     char *buf,
                     unsigned int buf_size,
                     unsigned int *buf_consumed,
                     hb_font_t *font,
                     hb_buffer_serialize_format_t format,
                     hb_buffer_serialize_flags_t flags)
{
  switch (buffer->content_type)
  {
 
    case HB_BUFFER_CONTENT_TYPE_GLYPHS:
      return hb_buffer_serialize_glyphs (buffer, start, end, buf, buf_size,
                     buf_consumed, font, format, flags);
 
    case HB_BUFFER_CONTENT_TYPE_UNICODE:
      return hb_buffer_serialize_unicode (buffer, start, end, buf, buf_size,
                      buf_consumed, format, flags);
 
    case HB_BUFFER_CONTENT_TYPE_INVALID:
    default:
      return _hb_buffer_serialize_invalid (buffer, start, end, buf, buf_size,
                       buf_consumed, format, flags);
  }
}
 
static bool
parse_int (const char *pp, const char *end, int32_t *pv)
{
  int v;
  const char *p = pp;
  if (unlikely (!hb_parse_int (&p, end, &v, true/* whole buffer */)))
    return false;
 
  *pv = v;
  return true;
}
 
static bool
parse_uint (const char *pp, const char *end, uint32_t *pv)
{
  unsigned int v;
  const char *p = pp;
  if (unlikely (!hb_parse_uint (&p, end, &v, true/* whole buffer */)))
    return false;
 
  *pv = v;
  return true;
}
 
static bool
parse_hex (const char *pp, const char *end, uint32_t *pv)
{
  unsigned int v;
  const char *p = pp;
  if (unlikely (!hb_parse_uint (&p, end, &v, true/* whole buffer */, 16)))
    return false;
 
  *pv = v;
  return true;
}
 
#include "hb-buffer-deserialize-json.hh"
#include "hb-buffer-deserialize-text.hh"
 
hb_bool_t
hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
                              const char *buf,
                              int buf_len, /* -1 means nul-terminated */
                              const char **end_ptr, /* May be NULL */
                              hb_font_t *font, /* May be NULL */
                              hb_buffer_serialize_format_t format)
{
  const char *end;
  if (!end_ptr)
    end_ptr = &end;
  *end_ptr = buf;
 
  buffer->assert_glyphs ();
 
  if (unlikely (hb_object_is_immutable (buffer)))
  {
    if (end_ptr)
      *end_ptr = buf;
    return false;
  }
 
  if (buf_len == -1)
    buf_len = strlen (buf);
 
  if (!buf_len)
  {
    *end_ptr = buf;
    return false;
  }
 
  hb_buffer_set_content_type (buffer, HB_BUFFER_CONTENT_TYPE_GLYPHS);
 
  if (!font)
    font = hb_font_get_empty ();
 
  switch (format)
  {
    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:
      return _hb_buffer_deserialize_text (buffer,
                                          buf, buf_len, end_ptr,
                                          font);
 
    case HB_BUFFER_SERIALIZE_FORMAT_JSON:
      return _hb_buffer_deserialize_json (buffer,
                                          buf, buf_len, end_ptr,
                                          font);
 
    default:
    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:
      return false;
 
  }
}
 
 
hb_bool_t
hb_buffer_deserialize_unicode (hb_buffer_t *buffer,
                               const char *buf,
                               int buf_len, /* -1 means nul-terminated */
                               const char **end_ptr, /* May be NULL */
                               hb_buffer_serialize_format_t format)
{
  const char *end;
  if (!end_ptr)
    end_ptr = &end;
  *end_ptr = buf;
 
  buffer->assert_unicode ();
 
  if (unlikely (hb_object_is_immutable (buffer)))
  {
    if (end_ptr)
      *end_ptr = buf;
    return false;
  }
 
  if (buf_len == -1)
    buf_len = strlen (buf);
 
  if (!buf_len)
  {
    *end_ptr = buf;
    return false;
  }
 
  hb_buffer_set_content_type (buffer, HB_BUFFER_CONTENT_TYPE_UNICODE);
 
  hb_font_t* font = hb_font_get_empty ();
 
  switch (format)
  {
    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:
      return _hb_buffer_deserialize_text (buffer,
                                          buf, buf_len, end_ptr,
                                          font);
 
    case HB_BUFFER_SERIALIZE_FORMAT_JSON:
      return _hb_buffer_deserialize_json (buffer,
                                          buf, buf_len, end_ptr,
                                          font);
 
    default:
    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:
      return false;
 
  }
}
 
 
#endif