qzdoom/game-music-emu/gme/Data_Reader.cpp

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// File_Extractor 0.4.0. http://www.slack.net/~ant/
#include "Data_Reader.h"
#include "blargg_endian.h"
#include <assert.h>
#include <string.h>
#include <stdio.h>
/* Copyright (C) 2005-2006 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
#include "blargg_source.h"
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#ifdef HAVE_ZLIB_H
#include <zlib.h>
#include <stdlib.h>
#include <errno.h>
static const unsigned char gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
#endif /* HAVE_ZLIB_H */
const char Data_Reader::eof_error [] = "Unexpected end of file";
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#define RETURN_VALIDITY_CHECK( cond ) \
do { if ( unlikely( !(cond) ) ) return "Corrupt file"; } while(0)
blargg_err_t Data_Reader::read( void* p, long s )
{
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RETURN_VALIDITY_CHECK( s > 0 );
long result = read_avail( p, s );
if ( result != s )
{
if ( result >= 0 && result < s )
return eof_error;
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return "Read error";
}
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return 0;
}
blargg_err_t Data_Reader::skip( long count )
{
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RETURN_VALIDITY_CHECK( count >= 0 );
char buf [512];
while ( count )
{
long n = sizeof buf;
if ( n > count )
n = count;
count -= n;
RETURN_ERR( read( buf, n ) );
}
return 0;
}
long File_Reader::remain() const { return size() - tell(); }
blargg_err_t File_Reader::skip( long n )
{
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RETURN_VALIDITY_CHECK( n >= 0 );
if ( !n )
return 0;
return seek( tell() + n );
}
// Subset_Reader
Subset_Reader::Subset_Reader( Data_Reader* dr, long size )
{
in = dr;
remain_ = dr->remain();
if ( remain_ > size )
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remain_ = max( 0l, size );
}
long Subset_Reader::remain() const { return remain_; }
long Subset_Reader::read_avail( void* p, long s )
{
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s = max( 0l, s );
if ( s > remain_ )
s = remain_;
remain_ -= s;
return in->read_avail( p, s );
}
// Remaining_Reader
Remaining_Reader::Remaining_Reader( void const* h, long size, Data_Reader* r )
{
header = (char const*) h;
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header_end = header + max( 0l, size );
in = r;
}
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long Remaining_Reader::remain() const { return header_end - header + in->remain(); }
long Remaining_Reader::read_first( void* out, long count )
{
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count = max( 0l, count );
long first = header_end - header;
if ( first )
{
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if ( first > count || first < 0 )
first = count;
void const* old = header;
header += first;
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memcpy( out, old, (size_t) first );
}
return first;
}
long Remaining_Reader::read_avail( void* out, long count )
{
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count = max( 0l, count );
long first = read_first( out, count );
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long second = max( 0l, count - first );
if ( second )
{
second = in->read_avail( (char*) out + first, second );
if ( second <= 0 )
return second;
}
return first + second;
}
blargg_err_t Remaining_Reader::read( void* out, long count )
{
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count = max( 0l, count );
long first = read_first( out, count );
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long second = max( 0l, count - first );
if ( !second )
return 0;
return in->read( (char*) out + first, second );
}
// Mem_File_Reader
Mem_File_Reader::Mem_File_Reader( const void* p, long s ) :
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m_begin( (const char*) p ),
m_size( max( 0l, s ) ),
m_pos( 0l )
{
#ifdef HAVE_ZLIB_H
if( !m_begin )
return;
if ( gz_decompress() )
{
debug_printf( "Loaded compressed data\n" );
m_ownedPtr = true;
}
#endif /* HAVE_ZLIB_H */
}
#ifdef HAVE_ZLIB_H
Mem_File_Reader::~Mem_File_Reader()
{
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if ( m_ownedPtr )
free( const_cast<char*>( m_begin ) ); // see gz_compress for the malloc
}
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#endif
long Mem_File_Reader::size() const { return m_size; }
long Mem_File_Reader::read_avail( void* p, long s )
{
long r = remain();
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if ( s > r || s < 0 )
s = r;
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memcpy( p, m_begin + m_pos, static_cast<size_t>(s) );
m_pos += s;
return s;
}
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long Mem_File_Reader::tell() const { return m_pos; }
blargg_err_t Mem_File_Reader::seek( long n )
{
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RETURN_VALIDITY_CHECK( n >= 0 );
if ( n > m_size )
return eof_error;
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m_pos = n;
return 0;
}
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#ifdef HAVE_ZLIB_H
bool Mem_File_Reader::gz_decompress()
{
if ( m_size >= 2 && memcmp(m_begin, gz_magic, 2) != 0 )
{
/* Don't try to decompress non-GZ files, just assign input pointer */
return false;
}
using vec_size = size_t;
const vec_size full_length = static_cast<vec_size>( m_size );
const vec_size half_length = static_cast<vec_size>( m_size / 2 );
// We use malloc/friends here so we can realloc to grow buffer if needed
char *raw_data = reinterpret_cast<char *> ( malloc( full_length ) );
size_t raw_data_size = full_length;
if ( !raw_data )
return false;
z_stream strm;
strm.next_in = const_cast<Bytef *>( reinterpret_cast<const Bytef *>( m_begin ) );
strm.avail_in = static_cast<uInt>( m_size );
strm.total_out = 0;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
bool done = false;
// Adding 16 sets bit 4, which enables zlib to auto-detect the
// header.
if ( inflateInit2(&strm, (16 + MAX_WBITS)) != Z_OK )
{
free( raw_data );
return false;
}
while ( !done )
{
/* If our output buffer is too small */
if ( strm.total_out >= raw_data_size )
{
raw_data_size += half_length;
raw_data = reinterpret_cast<char *>( realloc( raw_data, raw_data_size ) );
if ( !raw_data ) {
return false;
}
}
strm.next_out = reinterpret_cast<Bytef *>( raw_data + strm.total_out );
strm.avail_out = static_cast<uInt>( static_cast<uLong>( raw_data_size ) - strm.total_out );
/* Inflate another chunk. */
int err = inflate( &strm, Z_SYNC_FLUSH );
if ( err == Z_STREAM_END )
done = true;
else if ( err != Z_OK )
break;
}
if ( inflateEnd(&strm) != Z_OK )
{
free( raw_data );
return false;
}
m_begin = raw_data;
m_size = static_cast<long>( strm.total_out );
return true;
}
#endif /* HAVE_ZLIB_H */
// Callback_Reader
Callback_Reader::Callback_Reader( callback_t c, long size, void* d ) :
callback( c ),
data( d )
{
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remain_ = max( 0l, size );
}
long Callback_Reader::remain() const { return remain_; }
long Callback_Reader::read_avail( void* out, long count )
{
if ( count > remain_ )
count = remain_;
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if ( count < 0 || Callback_Reader::read( out, count ) )
count = -1;
return count;
}
blargg_err_t Callback_Reader::read( void* out, long count )
{
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RETURN_VALIDITY_CHECK( count >= 0 );
if ( count > remain_ )
return eof_error;
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return callback( data, out, (int) count );
}
// Std_File_Reader
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
static const char* get_gzip_eof( const char* path, long* eof )
{
FILE* file = fopen( path, "rb" );
if ( !file )
return "Couldn't open file";
unsigned char buf [4];
bool found_eof = false;
if ( fread( buf, 2, 1, file ) > 0 && buf [0] == 0x1F && buf [1] == 0x8B )
{
fseek( file, -4, SEEK_END );
if ( fread( buf, 4, 1, file ) > 0 ) {
*eof = get_le32( buf );
found_eof = true;
}
}
if ( !found_eof )
{
fseek( file, 0, SEEK_END );
*eof = ftell( file );
}
const char* err = (ferror( file ) || feof( file )) ? "Couldn't get file size" : nullptr;
fclose( file );
return err;
}
#endif
Std_File_Reader::Std_File_Reader() :
file_( nullptr )
#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
, size_( 0 )
#endif
{ }
Std_File_Reader::~Std_File_Reader() { close(); }
blargg_err_t Std_File_Reader::open( const char* path )
{
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
// zlib transparently handles uncompressed data if magic header
// not present but we still need to grab size
RETURN_ERR( get_gzip_eof( path, &size_ ) );
file_ = gzopen( path, "rb" );
#else
file_ = fopen( path, "rb" );
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#endif
if ( !file_ )
return "Couldn't open file";
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return nullptr;
}
long Std_File_Reader::size() const
{
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
if ( file_ )
return size_; // Set for both compressed and uncompressed modes
#endif
long pos = tell();
fseek( (FILE*) file_, 0, SEEK_END );
long result = tell();
fseek( (FILE*) file_, pos, SEEK_SET );
return result;
}
long Std_File_Reader::read_avail( void* p, long s )
{
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
if ( file_ && s > 0 && s <= UINT_MAX ) {
return gzread( reinterpret_cast<gzFile>(file_),
p, static_cast<unsigned>(s) );
}
return 0l;
#else
const size_t readLength = static_cast<size_t>( max( 0l, s ) );
const auto result = fread( p, 1, readLength, reinterpret_cast<FILE*>(file_) );
return static_cast<long>( result );
#endif /* HAVE_ZLIB_H */
}
blargg_err_t Std_File_Reader::read( void* p, long s )
{
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RETURN_VALIDITY_CHECK( s > 0 && s <= UINT_MAX );
#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
if ( file_ )
{
const auto &gzfile = reinterpret_cast<gzFile>( file_ );
if ( s == gzread( gzfile, p, static_cast<unsigned>( s ) ) )
return nullptr;
if ( gzeof( gzfile ) )
return eof_error;
return "Couldn't read from GZ file";
}
#endif
const auto &file = reinterpret_cast<FILE*>( file_ );
if ( s == static_cast<long>( fread( p, 1, static_cast<size_t>(s), file ) ) )
return 0;
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if ( feof( file ) )
return eof_error;
return "Couldn't read from file";
}
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long Std_File_Reader::tell() const
{
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
if ( file_ )
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return gztell( reinterpret_cast<gzFile>( file_ ) );
#endif
return ftell( reinterpret_cast<FILE*>( file_ ) );
}
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blargg_err_t Std_File_Reader::seek( long n )
{
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
if ( file_ )
{
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if ( gzseek( reinterpret_cast<gzFile>( file_ ), n, SEEK_SET ) >= 0 )
return nullptr;
if ( n > size_ )
return eof_error;
return "Error seeking in GZ file";
}
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#endif
if ( !fseek( reinterpret_cast<FILE*>( file_ ), n, SEEK_SET ) )
return nullptr;
if ( n > size() )
return eof_error;
return "Error seeking in file";
}
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void Std_File_Reader::close()
{
if ( file_ )
{
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#if 0//[ZDOOM:unneeded]def HAVE_ZLIB_H
gzclose( reinterpret_cast<gzFile>( file_ ) );
#else
fclose( reinterpret_cast<FILE*>( file_ ) );
#endif
file_ = nullptr;
}
}