/****************************************************************************
*
* ftgzip.c
*
* FreeType support for .gz compressed files.
*
* This optional component relies on zlib. It should mainly be used to
* parse compressed PCF fonts, as found with many X11 server
* distributions.
*
* Copyright (C) 2002-2023 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/ftmemory.h>
#include <freetype/internal/ftstream.h>
#include <freetype/internal/ftdebug.h>
#include <freetype/ftgzip.h>
#include FT_CONFIG_STANDARD_LIBRARY_H
#include <freetype/ftmoderr.h>
#undef FTERRORS_H_
#undef FT_ERR_PREFIX
#define FT_ERR_PREFIX Gzip_Err_
#define FT_ERR_BASE FT_Mod_Err_Gzip
#include <freetype/fterrors.h>
#ifdef FT_CONFIG_OPTION_USE_ZLIB
#ifdef FT_CONFIG_OPTION_SYSTEM_ZLIB
#include <zlib.h>
#else /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */
/* In this case, we include our own modified sources of the ZLib */
/* within the `gzip' component. The modifications were necessary */
/* to #include all files without conflicts, as well as preventing */
/* the definition of `extern' functions that may cause linking */
/* conflicts when a program is linked with both FreeType and the */
/* original ZLib. */
#ifndef USE_ZLIB_ZCALLOC
#define MY_ZCALLOC /* prevent all zcalloc() & zfree() in zutil.c */
#endif
/* Note that our `zlib.h' includes `ftzconf.h' instead of `zconf.h'; */
/* the main reason is that even a global `zlib.h' includes `zconf.h' */
/* with */
/* */
/* #include "zconf.h" */
/* */
/* instead of the expected */
/* */
/* #include <zconf.h> */
/* */
/* so that configuration with `FT_CONFIG_OPTION_SYSTEM_ZLIB' might */
/* include the wrong `zconf.h' file, leading to errors. */
#if defined( __GNUC__ ) || defined( __clang__ )
#define ZEXPORT
#define ZEXTERN static
#endif
#define HAVE_MEMCPY 1
#define Z_SOLO 1
#define Z_FREETYPE 1
#if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */
/* We disable the warning `conversion from XXX to YYY, */
/* possible loss of data' in order to compile cleanly with */
/* the maximum level of warnings: zlib is non-FreeType */
/* code. */
#pragma warning( push )
#pragma warning( disable : 4244 )
#endif /* _MSC_VER */
#if defined( __GNUC__ )
#pragma GCC diagnostic push
#ifndef __cplusplus
#pragma GCC diagnostic ignored "-Wstrict-prototypes"
#endif
#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
#pragma GCC diagnostic ignored "-Wredundant-decls"
#endif
#include "zutil.c"
#include "inffast.c"
#include "inflate.c"
#include "inftrees.c"
#include "adler32.c"
#include "crc32.c"
#if defined( __GNUC__ )
#pragma GCC diagnostic pop
#endif
#if defined( _MSC_VER )
#pragma warning( pop )
#endif
#endif /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */
/***************************************************************************/
/***************************************************************************/
/***** *****/
/***** Z L I B 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' */
static voidpf
ft_gzip_alloc( voidpf opaque,
uInt items,
uInt size )
{
FT_Memory memory = (FT_Memory)opaque;
FT_ULong sz = (FT_ULong)size * items;
FT_Error error;
FT_Pointer p = NULL;
/* allocate and zero out */
FT_MEM_ALLOC( p, sz );
return p;
}
static void
ft_gzip_free( voidpf opaque,
voidpf address )
{
FT_Memory memory = (FT_Memory)opaque;
FT_MEM_FREE( address );
}
/***************************************************************************/
/***************************************************************************/
/***** *****/
/***** Z L I B F I L E D E S C R I P T O R *****/
/***** *****/
/***************************************************************************/
/***************************************************************************/
#define FT_GZIP_BUFFER_SIZE 4096
typedef struct FT_GZipFileRec_
{
FT_Stream source; /* parent/source stream */
FT_Stream stream; /* embedding stream */
FT_Memory memory; /* memory allocator */
z_stream zstream; /* zlib input stream */
FT_ULong start; /* starting position, after .gz header */
FT_Byte input[FT_GZIP_BUFFER_SIZE]; /* input read buffer */
FT_Byte buffer[FT_GZIP_BUFFER_SIZE]; /* output buffer */
FT_ULong pos; /* position in output */
FT_Byte* cursor;
FT_Byte* limit;
} FT_GZipFileRec, *FT_GZipFile;
/* gzip flag byte */
#define FT_GZIP_ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define FT_GZIP_HEAD_CRC 0x02 /* bit 1 set: header CRC present */
#define FT_GZIP_EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define FT_GZIP_ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define FT_GZIP_COMMENT 0x10 /* bit 4 set: file comment present */
#define FT_GZIP_RESERVED 0xE0 /* bits 5..7: reserved */
/* check and skip .gz header - we don't support `transparent' compression */
static FT_Error
ft_gzip_check_header( FT_Stream stream )
{
FT_Error error;
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 method, and head[3] the flags */
if ( head[0] != 0x1F ||
head[1] != 0x8B ||
head[2] != Z_DEFLATED ||
(head[3] & FT_GZIP_RESERVED) )
{
error = FT_THROW( Invalid_File_Format );
goto Exit;
}
/* skip time, xflags and os code */
(void)FT_STREAM_SKIP( 6 );
/* skip the extra field */
if ( head[3] & FT_GZIP_EXTRA_FIELD )
{
FT_UInt len;
if ( FT_READ_USHORT_LE( len ) ||
FT_STREAM_SKIP( len ) )
goto Exit;
}
/* skip original file name */
if ( head[3] & FT_GZIP_ORIG_NAME )
for (;;)
{
FT_UInt c;
if ( FT_READ_BYTE( c ) )
goto Exit;
if ( c == 0 )
break;
}
/* skip .gz comment */
if ( head[3] & FT_GZIP_COMMENT )
for (;;)
{
FT_UInt c;
if ( FT_READ_BYTE( c ) )
goto Exit;
if ( c == 0 )
break;
}
/* skip CRC */
if ( head[3] & FT_GZIP_HEAD_CRC )
if ( FT_STREAM_SKIP( 2 ) )
goto Exit;
Exit:
return error;
}
static FT_Error
ft_gzip_file_init( FT_GZipFile zip,
FT_Stream stream,
FT_Stream source )
{
z_stream* zstream = &zip->zstream;
FT_Error error = FT_Err_Ok;
zip->stream = stream;
zip->source = source;
zip->memory = stream->memory;
zip->limit = zip->buffer + FT_GZIP_BUFFER_SIZE;
zip->cursor = zip->limit;
zip->pos = 0;
/* check and skip .gz header */
{
stream = source;
error = ft_gzip_check_header( stream );
if ( error )
goto Exit;
zip->start = FT_STREAM_POS();
}
/* initialize zlib -- there is no zlib header in the compressed stream */
zstream->zalloc = ft_gzip_alloc;
zstream->zfree = ft_gzip_free;
zstream->opaque = stream->memory;
zstream->avail_in = 0;
zstream->next_in = zip->buffer;
if ( inflateInit2( zstream, -MAX_WBITS ) != Z_OK ||
!zstream->next_in )
error = FT_THROW( Invalid_File_Format );
Exit:
return error;
}
static void
ft_gzip_file_done( FT_GZipFile zip )
{
z_stream* zstream = &zip->zstream;
inflateEnd( zstream );
/* clear the rest */
zstream->zalloc = NULL;
zstream->zfree = NULL;
zstream->opaque = NULL;
zstream->next_in = NULL;
zstream->next_out = NULL;
zstream->avail_in = 0;
zstream->avail_out = 0;
zip->memory = NULL;
zip->source = NULL;
zip->stream = NULL;
}
static FT_Error
ft_gzip_file_reset( FT_GZipFile zip )
{
FT_Stream stream = zip->source;
FT_Error error;
if ( !FT_STREAM_SEEK( zip->start ) )
{
z_stream* zstream = &zip->zstream;
inflateReset( zstream );
zstream->avail_in = 0;
zstream->next_in = zip->input;
zstream->avail_out = 0;
zstream->next_out = zip->buffer;
zip->limit = zip->buffer + FT_GZIP_BUFFER_SIZE;
zip->cursor = zip->limit;
zip->pos = 0;
}
return error;
}
static FT_Error
ft_gzip_file_fill_input( FT_GZipFile zip )
{
z_stream* zstream = &zip->zstream;
FT_Stream stream = zip->source;
FT_ULong size;
if ( stream->read )
{
size = stream->read( stream, stream->pos, zip->input,
FT_GZIP_BUFFER_SIZE );
if ( size == 0 )
{
zip->limit = zip->cursor;
return FT_THROW( Invalid_Stream_Operation );
}
}
else
{
size = stream->size - stream->pos;
if ( size > FT_GZIP_BUFFER_SIZE )
size = FT_GZIP_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;
zstream->next_in = zip->input;
zstream->avail_in = size;
return FT_Err_Ok;
}
static FT_Error
ft_gzip_file_fill_output( FT_GZipFile zip )
{
z_stream* zstream = &zip->zstream;
FT_Error error = FT_Err_Ok;
zip->cursor = zip->buffer;
zstream->next_out = zip->cursor;
zstream->avail_out = FT_GZIP_BUFFER_SIZE;
while ( zstream->avail_out > 0 )
{
int err;
if ( zstream->avail_in == 0 )
{
error = ft_gzip_file_fill_input( zip );
if ( error )
break;
}
err = inflate( zstream, Z_NO_FLUSH );
if ( err == Z_STREAM_END )
{
zip->limit = zstream->next_out;
if ( zip->limit == zip->cursor )
error = FT_THROW( Invalid_Stream_Operation );
break;
}
else if ( err != Z_OK )
{
zip->limit = zip->cursor;
error = FT_THROW( Invalid_Stream_Operation );
break;
}
}
return error;
}
/* fill output buffer; `count' must be <= FT_GZIP_BUFFER_SIZE */
static FT_Error
ft_gzip_file_skip_output( FT_GZipFile zip,
FT_ULong count )
{
FT_Error error = FT_Err_Ok;
for (;;)
{
FT_ULong 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_gzip_file_fill_output( zip );
if ( error )
break;
}
return error;
}
static FT_ULong
ft_gzip_file_io( FT_GZipFile 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_gzip_file_reset( zip );
if ( error )
goto Exit;
}
/* skip unwanted bytes */
if ( pos > zip->pos )
{
error = ft_gzip_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_gzip_file_fill_output( zip );
if ( error )
break;
}
Exit:
return result;
}
/***************************************************************************/
/***************************************************************************/
/***** *****/
/***** G Z E M B E D D I N G S T R E A M *****/
/***** *****/
/***************************************************************************/
/***************************************************************************/
static void
ft_gzip_stream_close( FT_Stream stream )
{
FT_GZipFile zip = (FT_GZipFile)stream->descriptor.pointer;
FT_Memory memory = stream->memory;
if ( zip )
{
/* finalize gzip file descriptor */
ft_gzip_file_done( zip );
FT_FREE( zip );
stream->descriptor.pointer = NULL;
}
if ( !stream->read )
FT_FREE( stream->base );
}
static unsigned long
ft_gzip_stream_io( FT_Stream stream,
unsigned long offset,
unsigned char* buffer,
unsigned long count )
{
FT_GZipFile zip = (FT_GZipFile)stream->descriptor.pointer;
return ft_gzip_file_io( zip, offset, buffer, count );
}
static FT_ULong
ft_gzip_get_uncompressed_size( FT_Stream stream )
{
FT_Error error;
FT_ULong old_pos;
FT_ULong result = 0;
old_pos = stream->pos;
if ( !FT_Stream_Seek( stream, stream->size - 4 ) )
{
result = FT_Stream_ReadULongLE( stream, &error );
if ( error )
result = 0;
(void)FT_Stream_Seek( stream, old_pos );
}
return result;
}
/* documentation is in ftgzip.h */
FT_EXPORT_DEF( FT_Error )
FT_Stream_OpenGzip( FT_Stream stream,
FT_Stream source )
{
FT_Error error;
FT_Memory memory;
FT_GZipFile zip = NULL;
if ( !stream || !source )
{
error = FT_THROW( Invalid_Stream_Handle );
goto Exit;
}
memory = source->memory;
/*
* check the header right now; this prevents allocating un-necessary
* objects when we don't need them
*/
error = ft_gzip_check_header( source );
if ( error )
goto Exit;
FT_ZERO( stream );
stream->memory = memory;
if ( !FT_QNEW( zip ) )
{
error = ft_gzip_file_init( zip, stream, source );
if ( error )
{
FT_FREE( zip );
goto Exit;
}
stream->descriptor.pointer = zip;
}
/*
* We use the following trick to try to dramatically improve the
* performance while dealing with small files. If the original stream
* size is less than a certain threshold, we try to load the whole font
* file into memory. This saves us from using the 32KB buffer needed
* to inflate the file, plus the two 4KB intermediate input/output
* buffers used in the `FT_GZipFile' structure.
*/
{
FT_ULong zip_size = ft_gzip_get_uncompressed_size( source );
if ( zip_size != 0 && zip_size < 40 * 1024 )
{
FT_Byte* zip_buff = NULL;
if ( !FT_QALLOC( zip_buff, zip_size ) )
{
FT_ULong count;
count = ft_gzip_file_io( zip, 0, zip_buff, zip_size );
if ( count == zip_size )
{
ft_gzip_file_done( zip );
FT_FREE( zip );
stream->descriptor.pointer = NULL;
stream->size = zip_size;
stream->pos = 0;
stream->base = zip_buff;
stream->read = NULL;
stream->close = ft_gzip_stream_close;
goto Exit;
}
ft_gzip_file_io( zip, 0, NULL, 0 );
FT_FREE( zip_buff );
}
error = FT_Err_Ok;
}
if ( zip_size )
stream->size = zip_size;
else
stream->size = 0x7FFFFFFFL; /* don't know the real size! */
}
stream->pos = 0;
stream->base = NULL;
stream->read = ft_gzip_stream_io;
stream->close = ft_gzip_stream_close;
Exit:
return error;
}
/* documentation is in ftgzip.h */
FT_EXPORT_DEF( FT_Error )
FT_Gzip_Uncompress( FT_Memory memory,
FT_Byte* output,
FT_ULong* output_len,
const FT_Byte* input,
FT_ULong input_len )
{
z_stream stream;
int err;
/* check for `input' delayed to `inflate' */
if ( !memory || !output_len || !output )
return FT_THROW( Invalid_Argument );
/* this function is modeled after zlib's `uncompress' function */
stream.next_in = (Bytef*)input;
stream.avail_in = (uInt)input_len;
stream.next_out = output;
stream.avail_out = (uInt)*output_len;
stream.zalloc = ft_gzip_alloc;
stream.zfree = ft_gzip_free;
stream.opaque = memory;
err = inflateInit2( &stream, MAX_WBITS|32 );
if ( err != Z_OK )
return FT_THROW( Invalid_Argument );
err = inflate( &stream, Z_FINISH );
if ( err != Z_STREAM_END )
{
inflateEnd( &stream );
if ( err == Z_OK )
err = Z_BUF_ERROR;
}
else
{
*output_len = stream.total_out;
err = inflateEnd( &stream );
}
if ( err == Z_MEM_ERROR )
return FT_THROW( Out_Of_Memory );
if ( err == Z_BUF_ERROR )
return FT_THROW( Array_Too_Large );
if ( err == Z_DATA_ERROR )
return FT_THROW( Invalid_Table );
if ( err == Z_NEED_DICT )
return FT_THROW( Invalid_Table );
return FT_Err_Ok;
}
#else /* !FT_CONFIG_OPTION_USE_ZLIB */
FT_EXPORT_DEF( FT_Error )
FT_Stream_OpenGzip( FT_Stream stream,
FT_Stream source )
{
FT_UNUSED( stream );
FT_UNUSED( source );
return FT_THROW( Unimplemented_Feature );
}
FT_EXPORT_DEF( FT_Error )
FT_Gzip_Uncompress( FT_Memory memory,
FT_Byte* output,
FT_ULong* output_len,
const FT_Byte* input,
FT_ULong input_len )
{
FT_UNUSED( memory );
FT_UNUSED( output );
FT_UNUSED( output_len );
FT_UNUSED( input );
FT_UNUSED( input_len );
return FT_THROW( Unimplemented_Feature );
}
#endif /* !FT_CONFIG_OPTION_USE_ZLIB */
/* END */
