// Program name: cfdata.h
// Programmed by: Anthony Barbachan
// Programmed in: C++ (Turbo C++ 3.0 Compatable)
// Purpose: Header file for a cabinet file data block object.
// Version: 1.00
// Last modified on: 11/5/1998
// Version: 1.00a
// Last modified on: 11/29/1998
// Changes: Removed undefined function.  Fixed program name.
// Version: 2.00
// Last modification date: 10-18-1999
// Changes: Replaced code with new classes' code.

#ifndef __CFDBLOCK_H__
#define __CFDBLOCK_H__

#include <fstream.h>
#include <cabinet/cftypes.h>
#include <cabinet/cfheader.h>

////////////////////////////////////////////////////////////////////////////////

class cabinet_datablock_fixed_header
{
	public:
		typedef unsigned long CHECKSUM;
	protected:
		dword csum;			// Checksum of this CF_Data entry
		word compressed_size;	// number of compressed bytes in this block
		word uncompressed_size;	// number of uncompressed bytes in this block
	private:
		void clear_variables() { memset(this, 0, sizeof(*this)); }
	public:
		cabinet_datablock_fixed_header() { clear_variables(); }
		~cabinet_datablock_fixed_header() {}

		void clear() { clear_variables(); }
		Error read(istream& in);
		Error write(ostream& out);

		dword get_checksum() { return csum; }
		void set_checksum(dword c) { csum = c; }
		word get_compressed_size() { return compressed_size; }
		void set_compressed_size(word s) { compressed_size = s; }
		word get_uncompressed_size() { return uncompressed_size; }
		void set_uncompressed_size(word s) { uncompressed_size = s; }
};

////////////////////////////////////////////////////////////////////////////////

class cabinet_datablock : protected cabinet_datablock_fixed_header
{
	protected:
		byte* reserved_area;	// (optional) per-datablock reserved area
		byte* compressed_data;	// compressed data bytes
		byte ra_size;		// (optional) size of per-folder reserved area
	private:
		void clear_variables()
		{
			reserved_area = NULL;
			compressed_data = NULL;
			ra_size = (byte) 0u;
		}
		void free_buffers()
		{
			if(reserved_area != NULL) delete[] reserved_area;
			if(compressed_data != NULL) delete[] compressed_data;
		}
		CHECKSUM CSUMCompute(byte* pv, unsigned cb, CHECKSUM seed);
	public:
		cabinet_datablock() { clear_variables(); }
		~cabinet_datablock() { free_buffers(); }

		void clear()
		{
			free_buffers();
			clear_variables();
			cabinet_datablock_fixed_header::clear();
		}
		int read(istream& in, cabinet_header& cab_header);
		int write(ostream& out);

		int checksum_ok(void);
		int checksum_not_ok(void);
		dword get_checksum() { return csum; }
		word get_compressed_size() { return compressed_size; }
		word get_uncompressed_size() { return uncompressed_size; }

		const byte* get_reserved_area() { return reserved_area; }
		const byte* get_compressed_data() { return compressed_data; }
		byte get_ra_size() { return ra_size; }
		void compute_checksum(void);
		void set_reserved_area(const byte* ra, byte len);
		void set_compressed_data(const byte* cdata, word csize, word usize);
};

////////////////////////////////////////////////////////////////////////////////

#endif