ref: ee19a6cbbcb28e7aab04dd13918edd46f21ecb22
dir: /src/base/ftstream.c/
/****************************************************************************
*
* ftstream.c
*
* I/O stream support (body).
*
* Copyright (C) 2000-2020 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/ftstream.h>
#include <freetype/internal/ftdebug.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 stream
FT_BASE_DEF( void )
FT_Stream_OpenMemory( FT_Stream stream,
const FT_Byte* base,
FT_ULong size )
{
stream->base = (FT_Byte*) base;
stream->size = size;
stream->pos = 0;
stream->cursor = NULL;
stream->read = NULL;
stream->close = NULL;
}
FT_BASE_DEF( void )
FT_Stream_Close( FT_Stream stream )
{
if ( stream && stream->close )
stream->close( stream );
}
FT_BASE_DEF( FT_Error )
FT_Stream_Seek( FT_Stream stream,
FT_ULong pos )
{
FT_Error error = FT_Err_Ok;
if ( stream->read )
{
if ( stream->read( stream, pos, 0, 0 ) )
{
FT_ERROR(( "FT_Stream_Seek:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
pos, stream->size ));
error = FT_THROW( Invalid_Stream_Operation );
}
}
/* note that seeking to the first position after the file is valid */
else if ( pos > stream->size )
{
FT_ERROR(( "FT_Stream_Seek:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
pos, stream->size ));
error = FT_THROW( Invalid_Stream_Operation );
}
if ( !error )
stream->pos = pos;
return error;
}
FT_BASE_DEF( FT_Error )
FT_Stream_Skip( FT_Stream stream,
FT_Long distance )
{
if ( distance < 0 )
return FT_THROW( Invalid_Stream_Operation );
return FT_Stream_Seek( stream, stream->pos + (FT_ULong)distance );
}
FT_BASE_DEF( FT_ULong )
FT_Stream_Pos( FT_Stream stream )
{
return stream->pos;
}
FT_BASE_DEF( FT_Error )
FT_Stream_Read( FT_Stream stream,
FT_Byte* buffer,
FT_ULong count )
{
return FT_Stream_ReadAt( stream, stream->pos, buffer, count );
}
FT_BASE_DEF( FT_Error )
FT_Stream_ReadAt( FT_Stream stream,
FT_ULong pos,
FT_Byte* buffer,
FT_ULong count )
{
FT_Error error = FT_Err_Ok;
FT_ULong read_bytes;
if ( pos >= stream->size )
{
FT_ERROR(( "FT_Stream_ReadAt:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
pos, stream->size ));
return FT_THROW( Invalid_Stream_Operation );
}
if ( stream->read )
read_bytes = stream->read( stream, pos, buffer, count );
else
{
read_bytes = stream->size - pos;
if ( read_bytes > count )
read_bytes = count;
FT_MEM_COPY( buffer, stream->base + pos, read_bytes );
}
stream->pos = pos + read_bytes;
if ( read_bytes < count )
{
FT_ERROR(( "FT_Stream_ReadAt:"
" invalid read; expected %lu bytes, got %lu\n",
count, read_bytes ));
error = FT_THROW( Invalid_Stream_Operation );
}
return error;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_TryRead( FT_Stream stream,
FT_Byte* buffer,
FT_ULong count )
{
FT_ULong read_bytes = 0;
if ( stream->pos >= stream->size )
goto Exit;
if ( stream->read )
read_bytes = stream->read( stream, stream->pos, buffer, count );
else
{
read_bytes = stream->size - stream->pos;
if ( read_bytes > count )
read_bytes = count;
FT_MEM_COPY( buffer, stream->base + stream->pos, read_bytes );
}
stream->pos += read_bytes;
Exit:
return read_bytes;
}
FT_BASE_DEF( FT_Error )
FT_Stream_ExtractFrame( FT_Stream stream,
FT_ULong count,
FT_Byte** pbytes )
{
FT_Error error;
error = FT_Stream_EnterFrame( stream, count );
if ( !error )
{
*pbytes = (FT_Byte*)stream->cursor;
/* equivalent to FT_Stream_ExitFrame(), with no memory block release */
stream->cursor = NULL;
stream->limit = NULL;
}
return error;
}
FT_BASE_DEF( void )
FT_Stream_ReleaseFrame( FT_Stream stream,
FT_Byte** pbytes )
{
if ( stream && stream->read )
{
FT_Memory memory = stream->memory;
#ifdef FT_DEBUG_MEMORY
ft_mem_free( memory, *pbytes );
#else
FT_FREE( *pbytes );
#endif
}
*pbytes = NULL;
}
FT_BASE_DEF( FT_Error )
FT_Stream_EnterFrame( FT_Stream stream,
FT_ULong count )
{
FT_Error error = FT_Err_Ok;
FT_ULong read_bytes;
FT_TRACE7(( "FT_Stream_EnterFrame: %ld bytes\n", count ));
/* check for nested frame access */
FT_ASSERT( stream && stream->cursor == 0 );
if ( stream->read )
{
/* allocate the frame in memory */
FT_Memory memory = stream->memory;
/* simple sanity check */
if ( count > stream->size )
{
FT_ERROR(( "FT_Stream_EnterFrame:"
" frame size (%lu) larger than stream size (%lu)\n",
count, stream->size ));
error = FT_THROW( Invalid_Stream_Operation );
goto Exit;
}
#ifdef FT_DEBUG_MEMORY
/* assume _ft_debug_file and _ft_debug_lineno are already set */
stream->base = (unsigned char*)ft_mem_qalloc( memory,
(FT_Long)count,
&error );
if ( error )
goto Exit;
#else
if ( FT_QALLOC( stream->base, count ) )
goto Exit;
#endif
/* read it */
read_bytes = stream->read( stream, stream->pos,
stream->base, count );
if ( read_bytes < count )
{
FT_ERROR(( "FT_Stream_EnterFrame:"
" invalid read; expected %lu bytes, got %lu\n",
count, read_bytes ));
FT_FREE( stream->base );
error = FT_THROW( Invalid_Stream_Operation );
}
stream->cursor = stream->base;
stream->limit = FT_OFFSET( stream->cursor, count );
stream->pos += read_bytes;
}
else
{
/* check current and new position */
if ( stream->pos >= stream->size ||
stream->size - stream->pos < count )
{
FT_ERROR(( "FT_Stream_EnterFrame:"
" invalid i/o; pos = 0x%lx, count = %lu, size = 0x%lx\n",
stream->pos, count, stream->size ));
error = FT_THROW( Invalid_Stream_Operation );
goto Exit;
}
/* set cursor */
stream->cursor = stream->base + stream->pos;
stream->limit = stream->cursor + count;
stream->pos += count;
}
Exit:
return error;
}
FT_BASE_DEF( void )
FT_Stream_ExitFrame( FT_Stream stream )
{
/* IMPORTANT: The assertion stream->cursor != 0 was removed, given */
/* that it is possible to access a frame of length 0 in */
/* some weird fonts (usually, when accessing an array of */
/* 0 records, like in some strange kern tables). */
/* */
/* In this case, the loader code handles the 0-length table */
/* gracefully; however, stream.cursor is really set to 0 by the */
/* FT_Stream_EnterFrame() call, and this is not an error. */
FT_TRACE7(( "FT_Stream_ExitFrame\n" ));
FT_ASSERT( stream );
if ( stream->read )
{
FT_Memory memory = stream->memory;
#ifdef FT_DEBUG_MEMORY
ft_mem_free( memory, stream->base );
stream->base = NULL;
#else
FT_FREE( stream->base );
#endif
}
stream->cursor = NULL;
stream->limit = NULL;
}
FT_BASE_DEF( FT_Char )
FT_Stream_GetChar( FT_Stream stream )
{
FT_Char result;
FT_ASSERT( stream && stream->cursor );
result = 0;
if ( stream->cursor < stream->limit )
result = (FT_Char)*stream->cursor++;
return result;
}
FT_BASE_DEF( FT_UShort )
FT_Stream_GetUShort( FT_Stream stream )
{
FT_Byte* p;
FT_UShort result;
FT_ASSERT( stream && stream->cursor );
result = 0;
p = stream->cursor;
if ( p + 1 < stream->limit )
result = FT_NEXT_USHORT( p );
stream->cursor = p;
return result;
}
FT_BASE_DEF( FT_UShort )
FT_Stream_GetUShortLE( FT_Stream stream )
{
FT_Byte* p;
FT_UShort result;
FT_ASSERT( stream && stream->cursor );
result = 0;
p = stream->cursor;
if ( p + 1 < stream->limit )
result = FT_NEXT_USHORT_LE( p );
stream->cursor = p;
return result;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_GetUOffset( FT_Stream stream )
{
FT_Byte* p;
FT_ULong result;
FT_ASSERT( stream && stream->cursor );
result = 0;
p = stream->cursor;
if ( p + 2 < stream->limit )
result = FT_NEXT_UOFF3( p );
stream->cursor = p;
return result;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_GetULong( FT_Stream stream )
{
FT_Byte* p;
FT_ULong result;
FT_ASSERT( stream && stream->cursor );
result = 0;
p = stream->cursor;
if ( p + 3 < stream->limit )
result = FT_NEXT_ULONG( p );
stream->cursor = p;
return result;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_GetULongLE( FT_Stream stream )
{
FT_Byte* p;
FT_ULong result;
FT_ASSERT( stream && stream->cursor );
result = 0;
p = stream->cursor;
if ( p + 3 < stream->limit )
result = FT_NEXT_ULONG_LE( p );
stream->cursor = p;
return result;
}
FT_BASE_DEF( FT_Char )
FT_Stream_ReadChar( FT_Stream stream,
FT_Error* error )
{
FT_Byte result = 0;
FT_ASSERT( stream );
*error = FT_Err_Ok;
if ( stream->read )
{
if ( stream->read( stream, stream->pos, &result, 1L ) != 1L )
goto Fail;
}
else
{
if ( stream->pos < stream->size )
result = stream->base[stream->pos];
else
goto Fail;
}
stream->pos++;
return (FT_Char)result;
Fail:
*error = FT_THROW( Invalid_Stream_Operation );
FT_ERROR(( "FT_Stream_ReadChar:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
stream->pos, stream->size ));
return 0;
}
FT_BASE_DEF( FT_UShort )
FT_Stream_ReadUShort( FT_Stream stream,
FT_Error* error )
{
FT_Byte reads[2];
FT_Byte* p = 0;
FT_UShort result = 0;
FT_ASSERT( stream );
*error = FT_Err_Ok;
if ( stream->pos + 1 < stream->size )
{
if ( stream->read )
{
if ( stream->read( stream, stream->pos, reads, 2L ) != 2L )
goto Fail;
p = reads;
}
else
p = stream->base + stream->pos;
if ( p )
result = FT_NEXT_USHORT( p );
}
else
goto Fail;
stream->pos += 2;
return result;
Fail:
*error = FT_THROW( Invalid_Stream_Operation );
FT_ERROR(( "FT_Stream_ReadUShort:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
stream->pos, stream->size ));
return 0;
}
FT_BASE_DEF( FT_UShort )
FT_Stream_ReadUShortLE( FT_Stream stream,
FT_Error* error )
{
FT_Byte reads[2];
FT_Byte* p = 0;
FT_UShort result = 0;
FT_ASSERT( stream );
*error = FT_Err_Ok;
if ( stream->pos + 1 < stream->size )
{
if ( stream->read )
{
if ( stream->read( stream, stream->pos, reads, 2L ) != 2L )
goto Fail;
p = reads;
}
else
p = stream->base + stream->pos;
if ( p )
result = FT_NEXT_USHORT_LE( p );
}
else
goto Fail;
stream->pos += 2;
return result;
Fail:
*error = FT_THROW( Invalid_Stream_Operation );
FT_ERROR(( "FT_Stream_ReadUShortLE:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
stream->pos, stream->size ));
return 0;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_ReadUOffset( FT_Stream stream,
FT_Error* error )
{
FT_Byte reads[3];
FT_Byte* p = 0;
FT_ULong result = 0;
FT_ASSERT( stream );
*error = FT_Err_Ok;
if ( stream->pos + 2 < stream->size )
{
if ( stream->read )
{
if (stream->read( stream, stream->pos, reads, 3L ) != 3L )
goto Fail;
p = reads;
}
else
p = stream->base + stream->pos;
if ( p )
result = FT_NEXT_UOFF3( p );
}
else
goto Fail;
stream->pos += 3;
return result;
Fail:
*error = FT_THROW( Invalid_Stream_Operation );
FT_ERROR(( "FT_Stream_ReadUOffset:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
stream->pos, stream->size ));
return 0;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_ReadULong( FT_Stream stream,
FT_Error* error )
{
FT_Byte reads[4];
FT_Byte* p = 0;
FT_ULong result = 0;
FT_ASSERT( stream );
*error = FT_Err_Ok;
if ( stream->pos + 3 < stream->size )
{
if ( stream->read )
{
if ( stream->read( stream, stream->pos, reads, 4L ) != 4L )
goto Fail;
p = reads;
}
else
p = stream->base + stream->pos;
if ( p )
result = FT_NEXT_ULONG( p );
}
else
goto Fail;
stream->pos += 4;
return result;
Fail:
*error = FT_THROW( Invalid_Stream_Operation );
FT_ERROR(( "FT_Stream_ReadULong:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
stream->pos, stream->size ));
return 0;
}
FT_BASE_DEF( FT_ULong )
FT_Stream_ReadULongLE( FT_Stream stream,
FT_Error* error )
{
FT_Byte reads[4];
FT_Byte* p = 0;
FT_ULong result = 0;
FT_ASSERT( stream );
*error = FT_Err_Ok;
if ( stream->pos + 3 < stream->size )
{
if ( stream->read )
{
if ( stream->read( stream, stream->pos, reads, 4L ) != 4L )
goto Fail;
p = reads;
}
else
p = stream->base + stream->pos;
if ( p )
result = FT_NEXT_ULONG_LE( p );
}
else
goto Fail;
stream->pos += 4;
return result;
Fail:
*error = FT_THROW( Invalid_Stream_Operation );
FT_ERROR(( "FT_Stream_ReadULongLE:"
" invalid i/o; pos = 0x%lx, size = 0x%lx\n",
stream->pos, stream->size ));
return 0;
}
FT_BASE_DEF( FT_Error )
FT_Stream_ReadFields( FT_Stream stream,
const FT_Frame_Field* fields,
void* structure )
{
FT_Error error;
FT_Bool frame_accessed = 0;
FT_Byte* cursor;
if ( !fields )
return FT_THROW( Invalid_Argument );
if ( !stream )
return FT_THROW( Invalid_Stream_Handle );
cursor = stream->cursor;
error = FT_Err_Ok;
do
{
FT_ULong value;
FT_Int sign_shift;
FT_Byte* p;
switch ( fields->value )
{
case ft_frame_start: /* access a new frame */
error = FT_Stream_EnterFrame( stream, fields->offset );
if ( error )
goto Exit;
frame_accessed = 1;
cursor = stream->cursor;
fields++;
continue; /* loop! */
case ft_frame_bytes: /* read a byte sequence */
case ft_frame_skip: /* skip some bytes */
{
FT_UInt len = fields->size;
if ( cursor + len > stream->limit )
{
error = FT_THROW( Invalid_Stream_Operation );
goto Exit;
}
if ( fields->value == ft_frame_bytes )
{
p = (FT_Byte*)structure + fields->offset;
FT_MEM_COPY( p, cursor, len );
}
cursor += len;
fields++;
continue;
}
case ft_frame_byte:
case ft_frame_schar: /* read a single byte */
value = FT_NEXT_BYTE( cursor );
sign_shift = 24;
break;
case ft_frame_short_be:
case ft_frame_ushort_be: /* read a 2-byte big-endian short */
value = FT_NEXT_USHORT( cursor );
sign_shift = 16;
break;
case ft_frame_short_le:
case ft_frame_ushort_le: /* read a 2-byte little-endian short */
value = FT_NEXT_USHORT_LE( cursor );
sign_shift = 16;
break;
case ft_frame_long_be:
case ft_frame_ulong_be: /* read a 4-byte big-endian long */
value = FT_NEXT_ULONG( cursor );
sign_shift = 0;
break;
case ft_frame_long_le:
case ft_frame_ulong_le: /* read a 4-byte little-endian long */
value = FT_NEXT_ULONG_LE( cursor );
sign_shift = 0;
break;
case ft_frame_off3_be:
case ft_frame_uoff3_be: /* read a 3-byte big-endian long */
value = FT_NEXT_UOFF3( cursor );
sign_shift = 8;
break;
case ft_frame_off3_le:
case ft_frame_uoff3_le: /* read a 3-byte little-endian long */
value = FT_NEXT_UOFF3_LE( cursor );
sign_shift = 8;
break;
default:
/* otherwise, exit the loop */
stream->cursor = cursor;
goto Exit;
}
/* now, compute the signed value is necessary */
if ( fields->value & FT_FRAME_OP_SIGNED )
value = (FT_ULong)( (FT_Int32)( value << sign_shift ) >> sign_shift );
/* finally, store the value in the object */
p = (FT_Byte*)structure + fields->offset;
switch ( fields->size )
{
case ( 8 / FT_CHAR_BIT ):
*(FT_Byte*)p = (FT_Byte)value;
break;
case ( 16 / FT_CHAR_BIT ):
*(FT_UShort*)p = (FT_UShort)value;
break;
case ( 32 / FT_CHAR_BIT ):
*(FT_UInt32*)p = (FT_UInt32)value;
break;
default: /* for 64-bit systems */
*(FT_ULong*)p = (FT_ULong)value;
}
/* go to next field */
fields++;
}
while ( 1 );
Exit:
/* close the frame if it was opened by this read */
if ( frame_accessed )
FT_Stream_ExitFrame( stream );
return error;
}
/* END */