0,0 → 1,413 |
/***************************************************************************/ |
/* */ |
/* ftlzw.c */ |
/* */ |
/* FreeType support for .Z compressed files. */ |
/* */ |
/* This optional component relies on NetBSD's zopen(). It should mainly */ |
/* be used to parse compressed PCF fonts, as found with many X11 server */ |
/* distributions. */ |
/* */ |
/* Copyright 2004-2006, 2009, 2010, 2012, 2013 by */ |
/* Albert Chin-A-Young. */ |
/* */ |
/* Based on code in src/gzip/ftgzip.c, Copyright 2004 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. */ |
/* */ |
/***************************************************************************/ |
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#include <ft2build.h> |
#include FT_INTERNAL_MEMORY_H |
#include FT_INTERNAL_STREAM_H |
#include FT_INTERNAL_DEBUG_H |
#include FT_LZW_H |
#include FT_CONFIG_STANDARD_LIBRARY_H |
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#include FT_MODULE_ERRORS_H |
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#undef __FTERRORS_H__ |
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#undef FT_ERR_PREFIX |
#define FT_ERR_PREFIX LZW_Err_ |
#define FT_ERR_BASE FT_Mod_Err_LZW |
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#include FT_ERRORS_H |
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#ifdef FT_CONFIG_OPTION_USE_LZW |
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#ifdef FT_CONFIG_OPTION_PIC |
#error "lzw code does not support PIC yet" |
#endif |
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#include "ftzopen.h" |
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/***************************************************************************/ |
/***************************************************************************/ |
/***** *****/ |
/***** M E M O R Y M A N A G E M E N T *****/ |
/***** *****/ |
/***************************************************************************/ |
/***************************************************************************/ |
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/***************************************************************************/ |
/***************************************************************************/ |
/***** *****/ |
/***** F I L E D E S C R I P T O R *****/ |
/***** *****/ |
/***************************************************************************/ |
/***************************************************************************/ |
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#define FT_LZW_BUFFER_SIZE 4096 |
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typedef struct FT_LZWFileRec_ |
{ |
FT_Stream source; /* parent/source stream */ |
FT_Stream stream; /* embedding stream */ |
FT_Memory memory; /* memory allocator */ |
FT_LzwStateRec lzw; /* lzw decompressor state */ |
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FT_Byte buffer[FT_LZW_BUFFER_SIZE]; /* output buffer */ |
FT_ULong pos; /* position in output */ |
FT_Byte* cursor; |
FT_Byte* limit; |
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} FT_LZWFileRec, *FT_LZWFile; |
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/* check and skip .Z header */ |
static FT_Error |
ft_lzw_check_header( FT_Stream stream ) |
{ |
FT_Error error; |
FT_Byte head[2]; |
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if ( FT_STREAM_SEEK( 0 ) || |
FT_STREAM_READ( head, 2 ) ) |
goto Exit; |
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/* head[0] && head[1] are the magic numbers */ |
if ( head[0] != 0x1f || |
head[1] != 0x9d ) |
error = FT_THROW( Invalid_File_Format ); |
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Exit: |
return error; |
} |
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static FT_Error |
ft_lzw_file_init( FT_LZWFile zip, |
FT_Stream stream, |
FT_Stream source ) |
{ |
FT_LzwState lzw = &zip->lzw; |
FT_Error error; |
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zip->stream = stream; |
zip->source = source; |
zip->memory = stream->memory; |
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zip->limit = zip->buffer + FT_LZW_BUFFER_SIZE; |
zip->cursor = zip->limit; |
zip->pos = 0; |
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/* check and skip .Z header */ |
error = ft_lzw_check_header( source ); |
if ( error ) |
goto Exit; |
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/* initialize internal lzw variable */ |
ft_lzwstate_init( lzw, source ); |
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Exit: |
return error; |
} |
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static void |
ft_lzw_file_done( FT_LZWFile zip ) |
{ |
/* clear the rest */ |
ft_lzwstate_done( &zip->lzw ); |
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zip->memory = NULL; |
zip->source = NULL; |
zip->stream = NULL; |
} |
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static FT_Error |
ft_lzw_file_reset( FT_LZWFile zip ) |
{ |
FT_Stream stream = zip->source; |
FT_Error error; |
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if ( !FT_STREAM_SEEK( 0 ) ) |
{ |
ft_lzwstate_reset( &zip->lzw ); |
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zip->limit = zip->buffer + FT_LZW_BUFFER_SIZE; |
zip->cursor = zip->limit; |
zip->pos = 0; |
} |
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return error; |
} |
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static FT_Error |
ft_lzw_file_fill_output( FT_LZWFile zip ) |
{ |
FT_LzwState lzw = &zip->lzw; |
FT_ULong count; |
FT_Error error = FT_Err_Ok; |
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zip->cursor = zip->buffer; |
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count = ft_lzwstate_io( lzw, zip->buffer, FT_LZW_BUFFER_SIZE ); |
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zip->limit = zip->cursor + count; |
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if ( count == 0 ) |
error = FT_THROW( Invalid_Stream_Operation ); |
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return error; |
} |
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/* fill output buffer; `count' must be <= FT_LZW_BUFFER_SIZE */ |
static FT_Error |
ft_lzw_file_skip_output( FT_LZWFile zip, |
FT_ULong count ) |
{ |
FT_Error error = FT_Err_Ok; |
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/* first, we skip what we can from the output buffer */ |
{ |
FT_ULong delta = (FT_ULong)( zip->limit - zip->cursor ); |
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if ( delta >= count ) |
delta = count; |
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zip->cursor += delta; |
zip->pos += delta; |
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count -= delta; |
} |
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/* next, we skip as many bytes remaining as possible */ |
while ( count > 0 ) |
{ |
FT_ULong delta = FT_LZW_BUFFER_SIZE; |
FT_ULong numread; |
|
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if ( delta > count ) |
delta = count; |
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numread = ft_lzwstate_io( &zip->lzw, NULL, delta ); |
if ( numread < delta ) |
{ |
/* not enough bytes */ |
error = FT_THROW( Invalid_Stream_Operation ); |
break; |
} |
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zip->pos += delta; |
count -= delta; |
} |
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return error; |
} |
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static FT_ULong |
ft_lzw_file_io( FT_LZWFile zip, |
FT_ULong pos, |
FT_Byte* buffer, |
FT_ULong count ) |
{ |
FT_ULong result = 0; |
FT_Error error; |
|
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/* seeking backwards. */ |
if ( pos < zip->pos ) |
{ |
/* If the new position is within the output buffer, simply */ |
/* decrement pointers, otherwise we reset the stream completely! */ |
if ( ( zip->pos - pos ) <= (FT_ULong)( zip->cursor - zip->buffer ) ) |
{ |
zip->cursor -= zip->pos - pos; |
zip->pos = pos; |
} |
else |
{ |
error = ft_lzw_file_reset( zip ); |
if ( error ) |
goto Exit; |
} |
} |
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/* skip unwanted bytes */ |
if ( pos > zip->pos ) |
{ |
error = ft_lzw_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) ); |
if ( error ) |
goto Exit; |
} |
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if ( count == 0 ) |
goto Exit; |
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/* now read the data */ |
for (;;) |
{ |
FT_ULong delta; |
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delta = (FT_ULong)( zip->limit - zip->cursor ); |
if ( delta >= count ) |
delta = count; |
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FT_MEM_COPY( buffer + result, zip->cursor, delta ); |
result += delta; |
zip->cursor += delta; |
zip->pos += delta; |
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count -= delta; |
if ( count == 0 ) |
break; |
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error = ft_lzw_file_fill_output( zip ); |
if ( error ) |
break; |
} |
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Exit: |
return result; |
} |
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/***************************************************************************/ |
/***************************************************************************/ |
/***** *****/ |
/***** L Z W E M B E D D I N G S T R E A M *****/ |
/***** *****/ |
/***************************************************************************/ |
/***************************************************************************/ |
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static void |
ft_lzw_stream_close( FT_Stream stream ) |
{ |
FT_LZWFile zip = (FT_LZWFile)stream->descriptor.pointer; |
FT_Memory memory = stream->memory; |
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if ( zip ) |
{ |
/* finalize lzw file descriptor */ |
ft_lzw_file_done( zip ); |
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FT_FREE( zip ); |
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stream->descriptor.pointer = NULL; |
} |
} |
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static FT_ULong |
ft_lzw_stream_io( FT_Stream stream, |
FT_ULong pos, |
FT_Byte* buffer, |
FT_ULong count ) |
{ |
FT_LZWFile zip = (FT_LZWFile)stream->descriptor.pointer; |
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return ft_lzw_file_io( zip, pos, buffer, count ); |
} |
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FT_EXPORT_DEF( FT_Error ) |
FT_Stream_OpenLZW( FT_Stream stream, |
FT_Stream source ) |
{ |
FT_Error error; |
FT_Memory memory = source->memory; |
FT_LZWFile zip = NULL; |
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/* |
* Check the header right now; this prevents allocation of a huge |
* LZWFile object (400 KByte of heap memory) if not necessary. |
* |
* Did I mention that you should never use .Z compressed font |
* files? |
*/ |
error = ft_lzw_check_header( source ); |
if ( error ) |
goto Exit; |
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FT_ZERO( stream ); |
stream->memory = memory; |
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if ( !FT_NEW( zip ) ) |
{ |
error = ft_lzw_file_init( zip, stream, source ); |
if ( error ) |
{ |
FT_FREE( zip ); |
goto Exit; |
} |
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stream->descriptor.pointer = zip; |
} |
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stream->size = 0x7FFFFFFFL; /* don't know the real size! */ |
stream->pos = 0; |
stream->base = 0; |
stream->read = ft_lzw_stream_io; |
stream->close = ft_lzw_stream_close; |
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Exit: |
return error; |
} |
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#include "ftzopen.c" |
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#else /* !FT_CONFIG_OPTION_USE_LZW */ |
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FT_EXPORT_DEF( FT_Error ) |
FT_Stream_OpenLZW( FT_Stream stream, |
FT_Stream source ) |
{ |
FT_UNUSED( stream ); |
FT_UNUSED( source ); |
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return FT_THROW( Unimplemented_Feature ); |
} |
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#endif /* !FT_CONFIG_OPTION_USE_LZW */ |
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/* END */ |