C++ png_memcpy函数代码示例

/* Initialize PNG structure for reading, and allocate any memory needed.
   This interface is deprecated in favour of the png_create_read_struct(),
   and it will eventually disappear. */
void
png_read_init(png_structp png_ptr)
{
   jmp_buf tmp_jmp;  /* to save current jump buffer */

   png_debug(1, "in png_read_init\n");
   /* save jump buffer and error functions */
   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));

   /* reset all variables to 0 */
   png_memset(png_ptr, 0, sizeof (png_struct));

   /* restore jump buffer */
   png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));

   /* initialize zbuf - compression buffer */
   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
     (png_uint_32)png_ptr->zbuf_size);
   png_ptr->zstream.zalloc = png_zalloc;
   png_ptr->zstream.zfree = png_zfree;
   png_ptr->zstream.opaque = (voidpf)png_ptr;

   switch (inflateInit(&png_ptr->zstream))
   {
     case Z_OK: /* Do nothing */ break;
     case Z_MEM_ERROR:
     case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
     case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
     default: png_error(png_ptr, "Unknown zlib error");
   }

   png_ptr->zstream.next_out = png_ptr->zbuf;
   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;

   png_set_read_fn(png_ptr, NULL, NULL);
}

void PNGAPI
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
{
   png_bytep ptr;

   ptr = buffer;
   if (png_ptr->save_buffer_size)
   {
      png_size_t save_size;

      if (length < png_ptr->save_buffer_size)
         save_size = length;
      else
         save_size = png_ptr->save_buffer_size;

      png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
      length -= save_size;
      ptr += save_size;
      png_ptr->buffer_size -= save_size;
      png_ptr->save_buffer_size -= save_size;
      png_ptr->save_buffer_ptr += save_size;
   }
   if (length && png_ptr->current_buffer_size)
   {
      png_size_t save_size;

      if (length < png_ptr->current_buffer_size)
         save_size = length;
      else
         save_size = png_ptr->current_buffer_size;

      png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
      png_ptr->buffer_size -= save_size;
      png_ptr->current_buffer_size -= save_size;
      png_ptr->current_buffer_ptr += save_size;
   }
}

static void PNGAPI
png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
   int check;
   png_byte *n_data;
   png_FILE_p io_ptr;

   if (png_ptr == NULL)
      return;
   /* Check if data really is near. If so, use usual code. */
   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
   if ((png_bytep)n_data == data)
   {
#if defined(_WIN32_WCE)
      if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
         check = 0;
#else
      check = fread(n_data, 1, length, io_ptr);
#endif
   }
   else
   {
      png_byte buf[NEAR_BUF_SIZE];
      png_size_t read, remaining, err;
      check = 0;
      remaining = length;
      do
      {
         read = MIN(NEAR_BUF_SIZE, remaining);
#if defined(_WIN32_WCE)
         if ( !ReadFile((HANDLE)(io_ptr), buf, read, &err, NULL) )
            err = 0;
#else
         err = fread(buf, (png_size_t)1, read, io_ptr);
#endif
         png_memcpy(data, buf, read); /* copy far buffer to near buffer */
         if (err != read)
            break;
         else
            check += err;
         data += read;
         remaining -= read;
      }
      while (remaining != 0);
   }
   if ((png_uint_32)check != (png_uint_32)length)
      png_error(png_ptr, "read Error");
}

void PNGAPI
png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
   png_uint_32 check;
   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
   png_FILE_p io_ptr;

   if (png_ptr == NULL) return;
   /* Check if data really is near. If so, use usual code. */
   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
   if ((png_bytep)near_data == data)
   {
#if defined(_WIN32_WCE)
      if ( !WriteFile(io_ptr, near_data, length, &check, NULL) )
         check = 0;
#else
      check = fwrite(near_data, 1, length, io_ptr);
#endif
   }
   else
   {
      png_byte buf[NEAR_BUF_SIZE];
      png_size_t written, remaining, err;
      check = 0;
      remaining = length;
      do
      {
         written = MIN(NEAR_BUF_SIZE, remaining);
         png_memcpy(buf, data, written); /* copy far buffer to near buffer */
#if defined(_WIN32_WCE)
         if ( !WriteFile(io_ptr, buf, written, &err, NULL) )
            err = 0;
#else
         err = fwrite(buf, 1, written, io_ptr);
#endif
         if (err != written)
            break;
         else
            check += err;
         data += written;
         remaining -= written;
      }
      while (remaining != 0);
   }
   if (check != length)
      png_error(png_ptr, "Write Error");
}

static void PNGCBAPI
png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
    png_size_t check;
    png_byte *n_data;
    png_FILE_p io_ptr;

    if (png_ptr == NULL)
        return;

    /* Check if data really is near. If so, use usual code. */
    n_data = (png_byte *)CVT_PTR_NOCHECK(data);
    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);

    if ((png_bytep)n_data == data)
    {
        check = fread(n_data, 1, length, io_ptr);
    }

    else
    {
        png_byte buf[NEAR_BUF_SIZE];
        png_size_t read, remaining, err;
        check = 0;
        remaining = length;

        do
        {
            read = MIN(NEAR_BUF_SIZE, remaining);
            err = fread(buf, 1, read, io_ptr);
            png_memcpy(data, buf, read); /* copy FAR buffer to near buffer */

            if (err != read)
                break;

            else
                check += err;

            data += read;
            remaining -= read;
        }
        while (remaining != 0);
    }

    if ((png_uint_32)check != (png_uint_32)length)
        png_error(png_ptr, "read Error");
}

static void
png_default_write_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
{
   png_uint_32 check;
   png_byte *n_data;

   /* Check if data really is near. If so, use usual code. */
#ifdef _MSC_VER
   /* do it this way just to quiet warning */
   FP_OFF(n_data) = FP_OFF(data);
   if (FP_SEG(n_data) == FP_SEG(data))
#else
   /* this works in MSC also but with lost segment warning */
   n_data = (png_byte *)data;
   if ((png_bytep)n_data == data)
#endif
   {
      check = fwrite(n_data, 1, (png_size_t)length, (FILE *)(png_ptr->io_ptr));
   }
   else
   {
      png_byte buf[NEAR_BUF_SIZE];
      png_size_t written, remaining, err;
      check = 0;
      remaining = (png_size_t)length;
      do
      {
         written = MIN(NEAR_BUF_SIZE, remaining);
         png_memcpy(buf, data, written); /* copy far buffer to near buffer */
         err = fwrite(buf, 1, written, (FILE *)(png_ptr->io_ptr));
         if (err != written)
            break;
         else
            check += err;
         data += written;
         remaining -= written;
      }
      while (remaining != 0);
   }
   if (check != length)
   {
      png_error(png_ptr, "Write Error");
   }
}

/* Convert the supplied time into an RFC 1123 string suitable for use in
 * a "Creation Time" or other text-based time string.
 */
png_charp PNGAPI
png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
{
   static PNG_CONST char short_months[12][4] =
        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

   if (png_ptr->time_buffer == NULL)
   {
      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
         sizeof(char)));
   }

#if defined(_WIN32_WCE)
   {
      wchar_t time_buf[29];
      wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
          ptime->day % 32, short_months[(ptime->month - 1) % 12],
        ptime->year, ptime->hour % 24, ptime->minute % 60,
          ptime->second % 61);
      WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
          NULL, NULL);
   }
#else
#ifdef USE_FAR_KEYWORD
   {
      char near_time_buf[29];
      sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
          ptime->day % 32, short_months[(ptime->month - 1) % 12],
          ptime->year, ptime->hour % 24, ptime->minute % 60,
          ptime->second % 61);
      png_memcpy(png_ptr->time_buffer, near_time_buf,
          29*sizeof(char));
   }
#else
   sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
       ptime->day % 32, short_months[(ptime->month - 1) % 12],
       ptime->year, ptime->hour % 24, ptime->minute % 60,
       ptime->second % 61);
#endif
#endif /* _WIN32_WCE */
   return ((png_charp)png_ptr->time_buffer);
}

void PNGAPI
png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
             png_const_colorp palette, int num_palette)
{

    png_debug1(1, "in %s storage function", "PLTE");

    if (png_ptr == NULL || info_ptr == NULL)
        return;

    if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH)
    {
        if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
            png_error(png_ptr, "Invalid palette length");

        else
        {
            png_warning(png_ptr, "Invalid palette length");
            return;
        }
    }

    /* It may not actually be necessary to set png_ptr->palette here;
     * we do it for backward compatibility with the way the png_handle_tRNS
     * function used to do the allocation.
     */
    png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0);

    /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead
     * of num_palette entries, in case of an invalid PNG file that has
     * too-large sample values.
     */
    png_ptr->palette = (png_colorp)png_calloc(png_ptr,
                       PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color));

    png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof(png_color));
    info_ptr->palette = png_ptr->palette;
    info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;

    info_ptr->free_me |= PNG_FREE_PLTE;

    info_ptr->valid |= PNG_INFO_PLTE;
}

void
png_read_tRNS(png_structp png_ptr, png_infop info,
   png_bytep trans, int num_trans,   png_color_16p trans_values)
{
   if (!png_ptr || !info)
      return;

   if (trans)
   {
      info->trans = trans;
   }
   else
   {
      png_memcpy(&(info->trans_values), trans_values,
         sizeof(png_color_16));
   }
   info->num_trans = (png_uint_16)num_trans;
   info->valid |= PNG_INFO_tRNS;
}

void
png_read_zTXt(png_structp png_ptr, png_infop info,
   png_charp key, png_charp text, png_uint_32 text_len, int compression)
{
   if (!png_ptr || !info)
      return;

   if (info->max_text <= info->num_text)
   {
      if (info->text)
      {
         png_uint_32 old_max;

         old_max = info->max_text;
         info->max_text = info->num_text + 16;
         {
            png_textp old_text;

            old_text = info->text;
            info->text = (png_textp)png_large_malloc(png_ptr,
               info->max_text * sizeof (png_text));
            png_memcpy(info->text, old_text,
               (png_size_t)(old_max * sizeof (png_text)));
            png_large_free(png_ptr, old_text);
         }
      }
      else
      {
         info->max_text = 16;
         info->num_text = 0;
         info->text = (png_textp)png_large_malloc(png_ptr,
            info->max_text * sizeof (png_text));
      }
   }

   info->text[info->num_text].key = key;
   info->text[info->num_text].text = text;
   info->text[info->num_text].text_length = text_len;
   info->text[info->num_text].compression = compression;
   info->num_text++;
}

void PNGAPI
png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time)
{
    png_debug1(1, "in %s storage function", "tIME");

    if (png_ptr == NULL || info_ptr == NULL ||
            (png_ptr->mode & PNG_WROTE_tIME))
        return;

    if (mod_time->month == 0   || mod_time->month > 12  ||
            mod_time->day   == 0   || mod_time->day   > 31  ||
            mod_time->hour  > 23   || mod_time->minute > 59 ||
            mod_time->second > 60)
    {
        png_warning(png_ptr, "Ignoring invalid time value");
        return;
    }

    png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time));
    info_ptr->valid |= PNG_INFO_tIME;
}

void
png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
   png_bytep trans, int num_trans, png_color_16p trans_values)
{
   png_debug1(1, "in %s storage function\n", "tRNS");
   if (png_ptr == NULL || info_ptr == NULL)
      return;

   if (trans != NULL)
      info_ptr->trans = trans;

   if (trans_values != NULL)
   {
      png_memcpy(&(info_ptr->trans_values), trans_values,
         sizeof(png_color_16));
      if (num_trans == 0)
        num_trans = 1;
   }
   info_ptr->num_trans = (png_uint_16)num_trans;
   info_ptr->valid |= PNG_INFO_tRNS;
}

static void
pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
   int check;
   png_byte *n_data;
   png_FILE_p io_ptr;

   /* Check if data really is near. If so, use usual code. */
   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
   if ((png_bytep)n_data == data)
   {
      READFILE(io_ptr, n_data, length, check);
   }
   else
   {
      png_byte buf[NEAR_BUF_SIZE];
      png_size_t read, remaining, err;
      check = 0;
      remaining = length;
      do
      {
         read = MIN(NEAR_BUF_SIZE, remaining);
         READFILE(io_ptr, buf, 1, err);
         png_memcpy(data, buf, read); /* copy far buffer to near buffer */
         if(err != read)
            break;
         else
            check += err;
         data += read;
         remaining -= read;
      }
      while (remaining != 0);
   }
   if (check != length)
   {
      png_error(png_ptr, "read Error");
   }
}

static void
png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
   png_uint_32 check;
   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
   FILE *io_ptr;

   /* Check if data really is near. If so, use usual code. */
   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
   io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr);
   if ((png_bytep)near_data == data)
   {
      check = fwrite(near_data, 1, length, io_ptr);
   }
   else
   {
      png_byte buf[NEAR_BUF_SIZE];
      png_size_t written, remaining, err;
      check = 0;
      remaining = length;
      do
      {
         written = MIN(NEAR_BUF_SIZE, remaining);
         png_memcpy(buf, data, written); /* copy far buffer to near buffer */
         err = fwrite(buf, 1, written, io_ptr);
         if (err != written)
            break;
         else
            check += err;
         data += written;
         remaining -= written;
      }
      while (remaining != 0);
   }
   if (check != length)
   {
      png_error(png_ptr, "Write Error");
   }
}

static void
png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
   png_uint_32 check;
   png_byte *near_data;
   FILE *io_ptr;

   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
   io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr);
   if ((png_bytep)near_data == data)
   {
      check = fwrite(near_data, 1, length, io_ptr);
   }
   else
   {
      png_byte buf[NEAR_BUF_SIZE];
      png_size_t written, remaining, err;
      check = 0;
      remaining = length;
      do
      {
         written = MIN(NEAR_BUF_SIZE, remaining);
         png_memcpy(buf, data, written);
         err = fwrite(buf, 1, written, io_ptr);
         if (err != written)
            break;
         else
            check += err;
         data += written;
         remaining -= written;
      }
      while (remaining != 0);
   }
   if (check != length)
   {
      png_error(png_ptr, "Write Error");
   }
}