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/***************************************************************************/
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/* FreeType support for .gz compressed files. */
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/* This optional component relies on zlib. It should mainly be used to */
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/* parse compressed PCF fonts, as found with many X11 server */
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/* Copyright 2002, 2003, 2004, 2005, 2006, 2009, 2010 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/***************************************************************************/
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#include FT_INTERNAL_MEMORY_H
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#include FT_INTERNAL_STREAM_H
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#include FT_INTERNAL_DEBUG_H
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#include FT_CONFIG_STANDARD_LIBRARY_H
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#include FT_MODULE_ERRORS_H
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#define FT_ERR_PREFIX Gzip_Err_
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#define FT_ERR_BASE FT_Mod_Err_Gzip
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#ifdef FT_CONFIG_OPTION_USE_ZLIB
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#ifdef FT_CONFIG_OPTION_PIC
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#error "gzip code does not support PIC yet"
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#ifdef FT_CONFIG_OPTION_SYSTEM_ZLIB
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#else /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */
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/* In this case, we include our own modified sources of the ZLib */
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/* within the "ftgzip" component. The modifications were necessary */
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/* to #include all files without conflicts, as well as preventing */
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/* the definition of "extern" functions that may cause linking */
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/* conflicts when a program is linked with both FreeType and the */
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#ifndef USE_ZLIB_ZCALLOC
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#define MY_ZCALLOC /* prevent all zcalloc() & zfree() in zutils.c */
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#define SLOW 1 /* we can't use asm-optimized sources here! */
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/* Urgh. `inflate_mask' must not be declared twice -- C++ doesn't like
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this. We temporarily disable it and load all necessary header files. */
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#define NO_INFLATE_MASK
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#undef NO_INFLATE_MASK
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/* infutil.c must be included before infcodes.c */
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#endif /* !FT_CONFIG_OPTION_SYSTEM_ZLIB */
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/***************************************************************************/
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/***************************************************************************/
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/***** Z L I B M E M O R Y M A N A G E M E N T *****/
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/***************************************************************************/
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/***************************************************************************/
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/* it is better to use FreeType memory routines instead of raw
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ft_gzip_alloc( FT_Memory memory,
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FT_ULong sz = (FT_ULong)size * items;
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(void)FT_ALLOC( p, sz );
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ft_gzip_free( FT_Memory memory,
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FT_MEM_FREE( address );
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#if !defined( FT_CONFIG_OPTION_SYSTEM_ZLIB ) && !defined( USE_ZLIB_ZCALLOC )
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zcalloc ( voidpf opaque,
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return ft_gzip_alloc( (FT_Memory)opaque, items, size );
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zcfree( voidpf opaque,
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ft_gzip_free( (FT_Memory)opaque, ptr );
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#endif /* !SYSTEM_ZLIB && !USE_ZLIB_ZCALLOC */
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/***************************************************************************/
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/***************************************************************************/
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/***** Z L I B F I L E D E S C R I P T O R *****/
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/***************************************************************************/
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/***************************************************************************/
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#define FT_GZIP_BUFFER_SIZE 4096
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typedef struct FT_GZipFileRec_
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FT_Stream source; /* parent/source stream */
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FT_Stream stream; /* embedding stream */
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FT_Memory memory; /* memory allocator */
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z_stream zstream; /* zlib input stream */
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FT_ULong start; /* starting position, after .gz header */
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FT_Byte input[FT_GZIP_BUFFER_SIZE]; /* input read buffer */
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FT_Byte buffer[FT_GZIP_BUFFER_SIZE]; /* output buffer */
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FT_ULong pos; /* position in output */
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} FT_GZipFileRec, *FT_GZipFile;
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#define FT_GZIP_ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
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#define FT_GZIP_HEAD_CRC 0x02 /* bit 1 set: header CRC present */
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#define FT_GZIP_EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
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#define FT_GZIP_ORIG_NAME 0x08 /* bit 3 set: original file name present */
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#define FT_GZIP_COMMENT 0x10 /* bit 4 set: file comment present */
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#define FT_GZIP_RESERVED 0xE0 /* bits 5..7: reserved */
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/* check and skip .gz header - we don't support `transparent' compression */
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ft_gzip_check_header( FT_Stream stream )
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if ( FT_STREAM_SEEK( 0 ) ||
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FT_STREAM_READ( head, 4 ) )
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/* head[0] && head[1] are the magic numbers; */
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/* head[2] is the method, and head[3] the flags */
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if ( head[0] != 0x1f ||
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head[2] != Z_DEFLATED ||
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(head[3] & FT_GZIP_RESERVED) )
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error = Gzip_Err_Invalid_File_Format;
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/* skip time, xflags and os code */
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(void)FT_STREAM_SKIP( 6 );
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/* skip the extra field */
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if ( head[3] & FT_GZIP_EXTRA_FIELD )
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if ( FT_READ_USHORT_LE( len ) ||
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FT_STREAM_SKIP( len ) )
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/* skip original file name */
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if ( head[3] & FT_GZIP_ORIG_NAME )
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if ( FT_READ_BYTE( c ) )
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/* skip .gz comment */
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if ( head[3] & FT_GZIP_COMMENT )
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if ( FT_READ_BYTE( c ) )
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if ( head[3] & FT_GZIP_HEAD_CRC )
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if ( FT_STREAM_SKIP( 2 ) )
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ft_gzip_file_init( FT_GZipFile zip,
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z_stream* zstream = &zip->zstream;
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FT_Error error = Gzip_Err_Ok;
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zip->stream = stream;
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zip->source = source;
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zip->memory = stream->memory;
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zip->limit = zip->buffer + FT_GZIP_BUFFER_SIZE;
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zip->cursor = zip->limit;
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/* check and skip .gz header */
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error = ft_gzip_check_header( stream );
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zip->start = FT_STREAM_POS();
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/* initialize zlib -- there is no zlib header in the compressed stream */
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zstream->zalloc = (alloc_func)ft_gzip_alloc;
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zstream->zfree = (free_func) ft_gzip_free;
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zstream->opaque = stream->memory;
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zstream->avail_in = 0;
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zstream->next_in = zip->buffer;
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if ( inflateInit2( zstream, -MAX_WBITS ) != Z_OK ||
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zstream->next_in == NULL )
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error = Gzip_Err_Invalid_File_Format;
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ft_gzip_file_done( FT_GZipFile zip )
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z_stream* zstream = &zip->zstream;
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inflateEnd( zstream );
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zstream->zalloc = NULL;
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zstream->zfree = NULL;
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zstream->opaque = NULL;
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zstream->next_in = NULL;
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zstream->next_out = NULL;
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zstream->avail_in = 0;
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zstream->avail_out = 0;
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ft_gzip_file_reset( FT_GZipFile zip )
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FT_Stream stream = zip->source;
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if ( !FT_STREAM_SEEK( zip->start ) )
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z_stream* zstream = &zip->zstream;
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inflateReset( zstream );
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zstream->avail_in = 0;
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zstream->next_in = zip->input;
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zstream->avail_out = 0;
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zstream->next_out = zip->buffer;
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zip->limit = zip->buffer + FT_GZIP_BUFFER_SIZE;
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zip->cursor = zip->limit;
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ft_gzip_file_fill_input( FT_GZipFile zip )
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z_stream* zstream = &zip->zstream;
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FT_Stream stream = zip->source;
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size = stream->read( stream, stream->pos, zip->input,
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FT_GZIP_BUFFER_SIZE );
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return Gzip_Err_Invalid_Stream_Operation;
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size = stream->size - stream->pos;
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if ( size > FT_GZIP_BUFFER_SIZE )
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size = FT_GZIP_BUFFER_SIZE;
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return Gzip_Err_Invalid_Stream_Operation;
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FT_MEM_COPY( zip->input, stream->base + stream->pos, size );
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zstream->next_in = zip->input;
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zstream->avail_in = size;
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ft_gzip_file_fill_output( FT_GZipFile zip )
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z_stream* zstream = &zip->zstream;
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FT_Error error = Gzip_Err_Ok;
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zip->cursor = zip->buffer;
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zstream->next_out = zip->cursor;
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zstream->avail_out = FT_GZIP_BUFFER_SIZE;
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while ( zstream->avail_out > 0 )
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if ( zstream->avail_in == 0 )
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error = ft_gzip_file_fill_input( zip );
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err = inflate( zstream, Z_NO_FLUSH );
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if ( err == Z_STREAM_END )
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zip->limit = zstream->next_out;
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if ( zip->limit == zip->cursor )
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error = Gzip_Err_Invalid_Stream_Operation;
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else if ( err != Z_OK )
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error = Gzip_Err_Invalid_Stream_Operation;
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/* fill output buffer; `count' must be <= FT_GZIP_BUFFER_SIZE */
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ft_gzip_file_skip_output( FT_GZipFile zip,
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FT_Error error = Gzip_Err_Ok;
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delta = (FT_ULong)( zip->limit - zip->cursor );
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if ( delta >= count )
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zip->cursor += delta;
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error = ft_gzip_file_fill_output( zip );
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ft_gzip_file_io( FT_GZipFile zip,
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/* Reset inflate stream if we're seeking backwards. */
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/* Yes, that is not too efficient, but it saves memory :-) */
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if ( pos < zip->pos )
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error = ft_gzip_file_reset( zip );
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/* skip unwanted bytes */
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if ( pos > zip->pos )
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error = ft_gzip_file_skip_output( zip, (FT_ULong)( pos - zip->pos ) );
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/* now read the data */
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delta = (FT_ULong)( zip->limit - zip->cursor );
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if ( delta >= count )
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FT_MEM_COPY( buffer, zip->cursor, delta );
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zip->cursor += delta;
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error = ft_gzip_file_fill_output( zip );
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/***************************************************************************/
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/***************************************************************************/
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/***** G Z E M B E D D I N G S T R E A M *****/
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/***************************************************************************/
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/***************************************************************************/
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ft_gzip_stream_close( FT_Stream stream )
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FT_GZipFile zip = (FT_GZipFile)stream->descriptor.pointer;
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FT_Memory memory = stream->memory;
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/* finalize gzip file descriptor */
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ft_gzip_file_done( zip );
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stream->descriptor.pointer = NULL;
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ft_gzip_stream_io( FT_Stream stream,
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FT_GZipFile zip = (FT_GZipFile)stream->descriptor.pointer;
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return ft_gzip_file_io( zip, pos, buffer, count );
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ft_gzip_get_uncompressed_size( FT_Stream stream )
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old_pos = stream->pos;
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if ( !FT_Stream_Seek( stream, stream->size - 4 ) )
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result = (FT_ULong)FT_Stream_ReadLong( stream, &error );
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(void)FT_Stream_Seek( stream, old_pos );
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FT_EXPORT_DEF( FT_Error )
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FT_Stream_OpenGzip( FT_Stream stream,
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FT_Memory memory = source->memory;
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* check the header right now; this prevents allocating un-necessary
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* objects when we don't need them
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error = ft_gzip_check_header( source );
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stream->memory = memory;
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if ( !FT_QNEW( zip ) )
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error = ft_gzip_file_init( zip, stream, source );
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stream->descriptor.pointer = zip;
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* We use the following trick to try to dramatically improve the
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* performance while dealing with small files. If the original stream
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* size is less than a certain threshold, we try to load the whole font
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* file into memory. This saves us from using the 32KB buffer needed
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* to inflate the file, plus the two 4KB intermediate input/output
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* buffers used in the `FT_GZipFile' structure.
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FT_ULong zip_size = ft_gzip_get_uncompressed_size( source );
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if ( zip_size != 0 && zip_size < 40 * 1024 )
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if ( !FT_ALLOC( zip_buff, zip_size ) )
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count = ft_gzip_file_io( zip, 0, zip_buff, zip_size );
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if ( count == zip_size )
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ft_gzip_file_done( zip );
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stream->descriptor.pointer = NULL;
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stream->size = zip_size;
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stream->base = zip_buff;
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stream->close = ft_gzip_stream_close;
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ft_gzip_file_io( zip, 0, NULL, 0 );
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stream->size = 0x7FFFFFFFL; /* don't know the real size! */
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stream->read = ft_gzip_stream_io;
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stream->close = ft_gzip_stream_close;
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#else /* !FT_CONFIG_OPTION_USE_ZLIB */
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FT_EXPORT_DEF( FT_Error )
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FT_Stream_OpenGzip( FT_Stream stream,
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return Gzip_Err_Unimplemented_Feature;
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#endif /* !FT_CONFIG_OPTION_USE_ZLIB */