#ifndef __FILE_HPP
#define __FILE_HPP

class File {
public:
	File()
	  { readLocks=writeLocks=0; }
	virtual ~File()
	  {}

	//info
	virtual long getFileSize() const			=0;
	virtual long seek(long offset, int fromwhere=0)		=0;
	virtual long tell() const				=0;

	//R/W
	virtual int read(void *buf, unsigned bytes) const	=0;
	virtual int write(const void *buf, unsigned bytes)	=0;
	virtual int chsize(long size)                           =0;
	//locking
	int writeLock();
	int readLock();
	int writeUnlock();
	int readUnlock();

protected:
	virtual int do_writeLock()				=0;
	virtual int do_readLock()				=0;
	virtual int do_writeUnlock()				=0;
	virtual int do_readUnlock()				=0;

protected:
	int writeLocks;
	int readLocks;
};


class TemporaryFile : public File {
public:
	TemporaryFile();
	~TemporaryFile();

	int create(unsigned long expectedSize);

	//info
	virtual long getFileSize() const;
	virtual long seek(long offset, int fromwhere);
	virtual long tell() const;

	//R/W
	virtual int read(void *buf, unsigned bytes) const;
	virtual int write(const void *buf, unsigned bytes);
	virtual int chsize(long size);

protected:
	virtual int do_writeLock();
	virtual int do_readLock();
	virtual int do_writeUnlock();
	virtual int do_readUnlock();

private:
	char filename[128];
	long currentSize;
	long currentPos;
	char *buffer;
	int buffersize;

	int fd;
};


class PersistentFile : public File {
public:
	PersistentFile(const char *fn);
	~PersistentFile();

	int open();
	int create(unsigned long expectedSize);
	int createtrunc(unsigned long expectedSize);

	//info
	virtual long getFileSize() const;
	virtual long seek(long offset, int fromwhere);
	virtual long tell() const;

	//R/W
	virtual int read(void *buf, unsigned bytes) const;
	virtual int write(const void *buf, unsigned bytes);
	virtual int chsize(long size);

protected:
	virtual int do_writeLock();
	virtual int do_readLock();
	virtual int do_writeUnlock();
	virtual int do_readUnlock();

private:
	char filename[128];

	int fd;
};

#endif