ref: c948df52e40bca30a510694cc6ca00b49abd334c
dir: /src/bzip2/ftbzip2.c/
/****************************************************************************
*
* ftbzip2.c
*
* FreeType support for .bz2 compressed files.
*
* This optional component relies on libbz2. It should mainly be used to
* parse compressed PCF fonts, as found with many X11 server
* distributions.
*
* Copyright (C) 2010-2020 by
* Joel Klinghed.
*
* based on `src/gzip/ftgzip.c'
*
* 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/ftmemory.h>
#include <freetype/internal/ftstream.h>
#include <freetype/internal/ftdebug.h>
#include <freetype/ftbzip2.h>
#include FT_CONFIG_STANDARD_LIBRARY_H
#include <freetype/ftmoderr.h>
#undef FTERRORS_H_
#undef FT_ERR_PREFIX
#define FT_ERR_PREFIX Bzip2_Err_
#define FT_ERR_BASE FT_Mod_Err_Bzip2
#include <freetype/fterrors.h>
#ifdef FT_CONFIG_OPTION_USE_BZIP2
#define BZ_NO_STDIO /* Do not need FILE */
#include <bzlib.h>
/***************************************************************************/
/***************************************************************************/
/***** *****/
/***** B Z I P 2 M E M O R Y M A N A G E M E N T *****/
/***** *****/
/***************************************************************************/
/***************************************************************************/
/* it is better to use FreeType memory routines instead of raw
'malloc/free' */
typedef void *(* alloc_func)(void*, int, int);
typedef void (* free_func)(void*, void*);
static void*
ft_bzip2_alloc( FT_Memory memory,
int items,
int size )
{
FT_ULong sz = (FT_ULong)size * (FT_ULong)items;
FT_Error error;
FT_Pointer p = NULL;
(void)FT_ALLOC( p, sz );
return p;
}
static void
ft_bzip2_free( FT_Memory memory,
void* address )
{
FT_MEM_FREE( address );
}
/***************************************************************************/
/***************************************************************************/
/***** *****/
/***** B Z I P 2 F I L E D E S C R I P T O R *****/
/***** *****/
/***************************************************************************/
/***************************************************************************/
#define FT_BZIP2_BUFFER_SIZE 4096
typedef struct FT_BZip2FileRec_
{
FT_Stream source; /* parent/source stream */
FT_Stream stream; /* embedding stream */
FT_Memory memory; /* memory allocator */
bz_stream bzstream; /* bzlib input stream */
FT_Byte input[FT_BZIP2_BUFFER_SIZE]; /* input read buffer */
FT_Byte buffer[FT_BZIP2_BUFFER_SIZE]; /* output buffer */
FT_ULong pos; /* position in output */
FT_Byte* cursor;
FT_Byte* limit;
} FT_BZip2FileRec, *FT_BZip2File;
/* check and skip .bz2 header - we don't support `transparent' compression */
static FT_Error
ft_bzip2_check_header( FT_Stream stream )
{
FT_Error error = FT_Err_Ok;
FT_Byte head[4];
if ( FT_STREAM_SEEK( 0 ) ||
FT_STREAM_READ( head, 4 ) )
goto Exit;
/* head[0] && head[1] are the magic numbers; */
/* head[2] is the version, and head[3] the blocksize */
if ( head[0] != 0x42 ||
head[1] != 0x5A ||
head[2] != 0x68 ) /* only support bzip2 (huffman) */
{
error = FT_THROW( Invalid_File_Format );
goto Exit;
}
Exit:
return error;
}
static FT_Error
ft_bzip2_file_init( FT_BZip2File zip,
FT_Stream stream,
FT_Stream source )
{
bz_stream* bzstream = &zip->bzstream;
FT_Error error = FT_Err_Ok;
zip->stream = stream;
zip->source = source;
zip->memory = stream->memory;
zip->limit = zip->buffer + FT_BZIP2_BUFFER_SIZE;
zip->cursor = zip->limit;
zip->pos = 0;
/* check .bz2 header */
{
stream = source;
error = ft_bzip2_check_header( stream );
if ( error )
goto Exit;
if ( FT_STREAM_SEEK( 0 ) )
goto Exit;
}
/* initialize bzlib */
bzstream->bzalloc = (alloc_func)ft_bzip2_alloc;
bzstream->bzfree = (free_func) ft_bzip2_free;
bzstream->opaque = zip->memory;
bzstream->avail_in = 0;
bzstream->next_in = (char*)zip->buffer;
if ( BZ2_bzDecompressInit( bzstream, 0, 0 ) != BZ_OK ||
!bzstream->next_in )
error = FT_THROW( Invalid_File_Format );
Exit:
return error;
}
static void
ft_bzip2_file_done( FT_BZip2File zip )
{
bz_stream* bzstream = &zip->bzstream;
BZ2_bzDecompressEnd( bzstream );
/* clear the rest */
bzstream->bzalloc = NULL;
bzstream->bzfree = NULL;
bzstream->opaque = NULL;
bzstream->next_in = NULL;
bzstream->next_out = NULL;
bzstream->avail_in = 0;
bzstream->avail_out = 0;
zip->memory = NULL;
zip->source = NULL;
zip->stream = NULL;
}
static FT_Error
ft_bzip2_file_reset( FT_BZip2File zip )
{
FT_Stream stream = zip->source;
FT_Error error;
if ( !FT_STREAM_SEEK( 0 ) )
{
bz_stream* bzstream = &zip->bzstream;
BZ2_bzDecompressEnd( bzstream );
bzstream->avail_in = 0;
bzstream->next_in = (char*)zip->input;
bzstream->avail_out = 0;
bzstream->next_out = (char*)zip->buffer;
zip->limit = zip->buffer + FT_BZIP2_BUFFER_SIZE;
zip->cursor = zip->limit;
zip->pos = 0;
BZ2_bzDecompressInit( bzstream, 0, 0 );
}
return error;
}
static FT_Error
ft_bzip2_file_fill_input( FT_BZip2File zip )
{
bz_stream* bzstream = &zip->bzstream;
FT_Stream stream = zip->source;
FT_ULong size;
if ( stream->read )
{
size = stream->read( stream, stream->pos, zip->input,
FT_BZIP2_BUFFER_SIZE );
if ( size == 0 )
{
zip->limit = zip->cursor;
return FT_THROW( Invalid_Stream_Operation );
}
}
else
{
size = stream->size - stream->pos;
if ( size > FT_BZIP2_BUFFER_SIZE )
size = FT_BZIP2_BUFFER_SIZE;
if ( size == 0 )
{
zip->limit = zip->cursor;
return FT_THROW( Invalid_Stream_Operation );
}
FT_MEM_COPY( zip->input, stream->base + stream->pos, size );
}
stream->pos += size;
bzstream->next_in = (char*)zip->input;
bzstream->avail_in = size;
return FT_Err_Ok;
}
static FT_Error
ft_bzip2_file_fill_output( FT_BZip2File zip )
{
bz_stream* bzstream = &zip->bzstream;
FT_Error error = FT_Err_Ok;
zip->cursor = zip->buffer;
bzstream->next_out = (char*)zip->cursor;
bzstream->avail_out = FT_BZIP2_BUFFER_SIZE;
while ( bzstream->avail_out > 0 )
{
int err;
if ( bzstream->avail_in == 0 )
{
error = ft_bzip2_file_fill_input( zip );
if ( error )
break;
}
err = BZ2_bzDecompress( bzstream );
if ( err == BZ_STREAM_END )
{
zip->limit = (FT_Byte*)bzstream->next_out;
if ( zip->limit == zip->cursor )
error = FT_THROW( Invalid_Stream_Operation );
break;
}
else if ( err != BZ_OK )
{
zip->limit = zip->cursor;
error = FT_THROW( Invalid_Stream_Operation );
break;
}
}
return error;
}
/* fill output buffer; `count' must be <= FT_BZIP2_BUFFER_SIZE */
static FT_Error
ft_bzip2_file_skip_output( FT_BZip2File zip,
FT_ULong count )
{
FT_Error error = FT_Err_Ok;
FT_ULong delta;
for (;;)
{
delta = (FT_ULong)( zip->limit - zip->cursor );
if ( delta >= count )
delta = count;
zip->cursor += delta;
zip->pos += delta;
count -= delta;
if ( count == 0 )
break;
error = ft_bzip2_file_fill_output( zip );
if ( error )
break;
}
return error;
}
static FT_ULong
ft_bzip2_file_io( FT_BZip2File zip,
FT_ULong pos,
FT_Byte* buffer,
FT_ULong count )
{
FT_ULong result = 0;
FT_Error error;
/* Reset inflate stream if we're seeking backwards. */
/* Yes, that is not too efficient, but it saves memory :-) */
if ( pos < zip->pos )
{
error = ft_bzip2_file_reset( zip );
if ( error )
goto Exit;
}
/* skip unwanted bytes */
if ( pos > zip->pos )
{
error = ft_bzip2_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) );
if ( error )
goto Exit;
}
if ( count == 0 )
goto Exit;
/* now read the data */
for (;;)
{
FT_ULong delta;
delta = (FT_ULong)( zip->limit - zip->cursor );
if ( delta >= count )
delta = count;
FT_MEM_COPY( buffer, zip->cursor, delta );
buffer += delta;
result += delta;
zip->cursor += delta;
zip->pos += delta;
count -= delta;
if ( count == 0 )
break;
error = ft_bzip2_file_fill_output( zip );
if ( error )
break;
}
Exit:
return result;
}
/***************************************************************************/
/***************************************************************************/
/***** *****/
/***** B Z E M B E D D I N G S T R E A M *****/
/***** *****/
/***************************************************************************/
/***************************************************************************/
static void
ft_bzip2_stream_close( FT_Stream stream )
{
FT_BZip2File zip = (FT_BZip2File)stream->descriptor.pointer;
FT_Memory memory = stream->memory;
if ( zip )
{
/* finalize bzip file descriptor */
ft_bzip2_file_done( zip );
FT_FREE( zip );
stream->descriptor.pointer = NULL;
}
}
static unsigned long
ft_bzip2_stream_io( FT_Stream stream,
unsigned long offset,
unsigned char* buffer,
unsigned long count )
{
FT_BZip2File zip = (FT_BZip2File)stream->descriptor.pointer;
return ft_bzip2_file_io( zip, offset, buffer, count );
}
FT_EXPORT_DEF( FT_Error )
FT_Stream_OpenBzip2( FT_Stream stream,
FT_Stream source )
{
FT_Error error;
FT_Memory memory;
FT_BZip2File zip = NULL;
if ( !stream || !source )
{
error = FT_THROW( Invalid_Stream_Handle );
goto Exit;
}
memory = source->memory;
/*
* check the header right now; this prevents allocating unnecessary
* objects when we don't need them
*/
error = ft_bzip2_check_header( source );
if ( error )
goto Exit;
FT_ZERO( stream );
stream->memory = memory;
if ( !FT_QNEW( zip ) )
{
error = ft_bzip2_file_init( zip, stream, source );
if ( error )
{
FT_FREE( zip );
goto Exit;
}
stream->descriptor.pointer = zip;
}
stream->size = 0x7FFFFFFFL; /* don't know the real size! */
stream->pos = 0;
stream->base = 0;
stream->read = ft_bzip2_stream_io;
stream->close = ft_bzip2_stream_close;
Exit:
return error;
}
#else /* !FT_CONFIG_OPTION_USE_BZIP2 */
FT_EXPORT_DEF( FT_Error )
FT_Stream_OpenBzip2( FT_Stream stream,
FT_Stream source )
{
FT_UNUSED( stream );
FT_UNUSED( source );
return FT_THROW( Unimplemented_Feature );
}
#endif /* !FT_CONFIG_OPTION_USE_BZIP2 */
/* END */