bsnes/snesreader/fex/Zlib_Inflater.h

71 lines
2.2 KiB
C++
Executable File

// Simplifies use of zlib for inflating data
// File_Extractor 1.0.0
#ifndef ZLIB_INFLATER_H
#define ZLIB_INFLATER_H
#include "blargg_common.h"
#include "Data_Reader.h"
#include "zlib/zlib.h"
class Zlib_Inflater {
public:
// Reads at most min(*count,bytes_until_eof()) bytes into *out and set *count
// to that number, or returns error if that many can't be read.
typedef blargg_err_t (*callback_t)( void* user_data, void* out, int* count );
// Begins by setting callback and filling buffer. Default buffer is 16K and
// filled to 4K, or specify buf_size and initial_read for custom buffer size
// and how much to read initially.
blargg_err_t begin( callback_t, void* user_data,
int buf_size = 0, int initial_read = 0 );
// Data read into buffer by begin()
const unsigned char* data() const { return zbuf.next_in; }
int filled() const { return zbuf.avail_in; }
// Begins inflation using specified mode. Using mode_auto selects between
// mode_copy and mode_ungz by examining first two bytes of buffer. Use
// buf_offset to specify where data begins in buffer, in case there is
// header data that should be skipped.
enum mode_t { mode_copy, mode_ungz, mode_raw_deflate, mode_auto };
blargg_err_t set_mode( mode_t, int buf_offset = 0 );
// True if set_mode() has been called with mode_ungz or mode_raw_deflate
bool deflated() const { return deflated_; }
// Reads/inflates at most *count_io bytes into *out and sets *count_io to actual
// number of bytes read (less than requested if end of data was reached).
// Buffers source data internally, even in copy mode, so input file can be
// unbuffered without sacrificing performance.
blargg_err_t read( void* out, int* count_io );
// Total number of bytes read since begin()
int tell() const { return zbuf.total_out; }
// Ends inflation and frees memory
void end();
private:
// noncopyable
Zlib_Inflater( const Zlib_Inflater& );
Zlib_Inflater& operator = ( const Zlib_Inflater& );
// Implementation
public:
Zlib_Inflater();
~Zlib_Inflater();
private:
z_stream_s zbuf;
blargg_vector<unsigned char> buf;
bool deflated_;
callback_t callback;
void* user_data;
blargg_err_t fill_buf( int count );
};
#endif