ref: eb2b5bb10754da426b4ea9da78fbb017f0bcb9ec
dir: /src/cid/cidparse.c/
/****************************************************************************
*
* cidparse.c
*
* CID-keyed Type1 parser (body).
*
* Copyright (C) 1996-2020 by
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* This file is part of the FreeType project, and may only be used,
* modified, and distributed under the terms of the FreeType project
* license, LICENSE.TXT. By continuing to use, modify, or distribute
* this file you indicate that you have read the license and
* understand and accept it fully.
*
*/
#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftobjs.h>
#include <freetype/internal/ftstream.h>
#include "cidparse.h"
#include "ciderrs.h"
/**************************************************************************
*
* The macro FT_COMPONENT is used in trace mode. It is an implicit
* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
* messages during execution.
*/
#undef FT_COMPONENT
#define FT_COMPONENT cidparse
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** INPUT STREAM PARSER *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#define STARTDATA "StartData"
#define STARTDATA_LEN ( sizeof ( STARTDATA ) - 1 )
#define SFNTS "/sfnts"
#define SFNTS_LEN ( sizeof ( SFNTS ) - 1 )
FT_LOCAL_DEF( FT_Error )
cid_parser_new( CID_Parser* parser,
FT_Stream stream,
FT_Memory memory,
PSAux_Service psaux )
{
FT_Error error;
FT_ULong base_offset, offset, ps_len;
FT_Byte *cur, *limit;
FT_Byte *arg1, *arg2;
FT_ZERO( parser );
psaux->ps_parser_funcs->init( &parser->root, 0, 0, memory );
parser->stream = stream;
base_offset = FT_STREAM_POS();
/* first of all, check the font format in the header */
if ( FT_FRAME_ENTER( 31 ) )
goto Exit;
if ( ft_strncmp( (char *)stream->cursor,
"%!PS-Adobe-3.0 Resource-CIDFont", 31 ) )
{
FT_TRACE2(( " not a CID-keyed font\n" ));
error = FT_THROW( Unknown_File_Format );
}
FT_FRAME_EXIT();
if ( error )
goto Exit;
Again:
/* now, read the rest of the file until we find */
/* `StartData' or `/sfnts' */
{
/*
* The algorithm is as follows (omitting the case with less than 256
* bytes to fill for simplicity).
*
* 1. Fill the buffer with 256 + STARTDATA_LEN bytes.
*
* 2. Search for the STARTDATA and SFNTS strings at positions
* buffer[0], buffer[1], ...,
* buffer[255 + STARTDATA_LEN - SFNTS_LEN].
*
* 3. Move the last STARTDATA_LEN bytes to buffer[0].
*
* 4. Fill the buffer with 256 bytes, starting at STARTDATA_LEN.
*
* 5. Repeat with step 2.
*
*/
FT_Byte buffer[256 + STARTDATA_LEN + 1];
/* values for the first loop */
FT_ULong read_len = 256 + STARTDATA_LEN;
FT_ULong read_offset = 0;
FT_Byte* p = buffer;
for ( offset = FT_STREAM_POS(); ; offset += 256 )
{
FT_ULong stream_len;
stream_len = stream->size - FT_STREAM_POS();
read_len = FT_MIN( read_len, stream_len );
if ( FT_STREAM_READ( p, read_len ) )
goto Exit;
/* ensure that we do not compare with data beyond the buffer */
p[read_len] = '\0';
limit = p + read_len - SFNTS_LEN;
for ( p = buffer; p < limit; p++ )
{
if ( p[0] == 'S' &&
ft_strncmp( (char*)p, STARTDATA, STARTDATA_LEN ) == 0 )
{
/* save offset of binary data after `StartData' */
offset += (FT_ULong)( p - buffer ) + STARTDATA_LEN + 1;
goto Found;
}
else if ( p[1] == 's' &&
ft_strncmp( (char*)p, SFNTS, SFNTS_LEN ) == 0 )
{
offset += (FT_ULong)( p - buffer ) + SFNTS_LEN + 1;
goto Found;
}
}
if ( read_offset + read_len < STARTDATA_LEN )
{
FT_TRACE2(( "cid_parser_new: no `StartData' keyword found\n" ));
error = FT_THROW( Invalid_File_Format );
goto Exit;
}
FT_MEM_MOVE( buffer,
buffer + read_offset + read_len - STARTDATA_LEN,
STARTDATA_LEN );
/* values for the next loop */
read_len = 256;
read_offset = STARTDATA_LEN;
p = buffer + read_offset;
}
}
Found:
/* We have found the start of the binary data or the `/sfnts' token. */
/* Now rewind and extract the frame corresponding to this PostScript */
/* section. */
ps_len = offset - base_offset;
if ( FT_STREAM_SEEK( base_offset ) ||
FT_FRAME_EXTRACT( ps_len, parser->postscript ) )
goto Exit;
parser->data_offset = offset;
parser->postscript_len = ps_len;
parser->root.base = parser->postscript;
parser->root.cursor = parser->postscript;
parser->root.limit = parser->root.cursor + ps_len;
parser->num_dict = -1;
/* Finally, we check whether `StartData' or `/sfnts' was real -- */
/* it could be in a comment or string. We also get the arguments */
/* of `StartData' to find out whether the data is represented in */
/* binary or hex format. */
arg1 = parser->root.cursor;
cid_parser_skip_PS_token( parser );
cid_parser_skip_spaces ( parser );
arg2 = parser->root.cursor;
cid_parser_skip_PS_token( parser );
cid_parser_skip_spaces ( parser );
limit = parser->root.limit;
cur = parser->root.cursor;
while ( cur <= limit - SFNTS_LEN )
{
if ( parser->root.error )
{
error = parser->root.error;
goto Exit;
}
if ( cur[0] == 'S' &&
cur <= limit - STARTDATA_LEN &&
ft_strncmp( (char*)cur, STARTDATA, STARTDATA_LEN ) == 0 )
{
if ( ft_strncmp( (char*)arg1, "(Hex)", 5 ) == 0 )
{
FT_Long tmp = ft_strtol( (const char *)arg2, NULL, 10 );
if ( tmp < 0 )
{
FT_ERROR(( "cid_parser_new: invalid length of hex data\n" ));
error = FT_THROW( Invalid_File_Format );
}
else
parser->binary_length = (FT_ULong)tmp;
}
goto Exit;
}
else if ( cur[1] == 's' &&
ft_strncmp( (char*)cur, SFNTS, SFNTS_LEN ) == 0 )
{
FT_TRACE2(( "cid_parser_new: cannot handle Type 11 fonts\n" ));
error = FT_THROW( Unknown_File_Format );
goto Exit;
}
cid_parser_skip_PS_token( parser );
cid_parser_skip_spaces ( parser );
arg1 = arg2;
arg2 = cur;
cur = parser->root.cursor;
}
/* we haven't found the correct `StartData'; go back and continue */
/* searching */
FT_FRAME_RELEASE( parser->postscript );
if ( !FT_STREAM_SEEK( offset ) )
goto Again;
Exit:
return error;
}
#undef STARTDATA
#undef STARTDATA_LEN
#undef SFNTS
#undef SFNTS_LEN
FT_LOCAL_DEF( void )
cid_parser_done( CID_Parser* parser )
{
/* always free the private dictionary */
if ( parser->postscript )
{
FT_Stream stream = parser->stream;
FT_FRAME_RELEASE( parser->postscript );
}
parser->root.funcs.done( &parser->root );
}
/* END */