db_cxx.h

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	// since it is implemented via a pointer.
	// (see comment at top)

	// Note: use DbEnv::memp_fcreate() to get pointers to a DbMpoolFile,
	// and call DbMpoolFile::close() rather than delete to release them.
	//
	DbMpoolFile();

	// Shut g++ up.
protected:
	virtual ~DbMpoolFile();

private:
	// no copying
	DbMpoolFile(const DbMpoolFile &);
	void operator = (const DbMpoolFile &);
};

//
// This is filled in and returned by the DbEnv::txn_recover() method.
//
class _exported DbPreplist
{
public:
	DbTxn *txn;
	u_int8_t gid[DB_XIDDATASIZE];
};

//
// A sequence record in a database
//
class _exported DbSequence
{
public:
	DbSequence(Db *db, u_int32_t flags);
	virtual ~DbSequence();

	int open(DbTxn *txnid, Dbt *key, u_int32_t flags);
	int initial_value(db_seq_t value);
	int close(u_int32_t flags);
	int remove(DbTxn *txnid, u_int32_t flags);
	int stat(DB_SEQUENCE_STAT **sp, u_int32_t flags);
	int stat_print(u_int32_t flags);
	
	int get(DbTxn *txnid, int32_t delta, db_seq_t *retp, u_int32_t flags);
	int get_cachesize(int32_t *sizep);
	int set_cachesize(int32_t size);
	int get_flags(u_int32_t *flagsp);
	int set_flags(u_int32_t flags);
	int get_range(db_seq_t *minp, db_seq_t *maxp);
	int set_range(db_seq_t min, db_seq_t max);

	Db *get_db();
	Dbt *get_key();

	virtual DB_SEQUENCE *get_DB_SEQUENCE()
	{
		return imp_;
	}

	virtual const DB_SEQUENCE *get_const_DB_SEQUENCE() const
	{
		return imp_;
	}

	static DbSequence* get_DbSequence(DB_SEQUENCE *seq)
	{
		return (DbSequence *)seq->api_internal;
	}

	static const DbSequence* get_const_DbSequence(const DB_SEQUENCE *seq)
	{
		return (const DbSequence *)seq->api_internal;
	}

	// For internal use only.
	static DbSequence* wrap_DB_SEQUENCE(DB_SEQUENCE *seq);

private:
	DbSequence(DB_SEQUENCE *seq);
	// no copying
	DbSequence(const DbSequence &);
	DbSequence &operator = (const DbSequence &);

	DB_SEQUENCE *imp_;
	DBT key_;
};

//
// Transaction
//
class _exported DbTxn
{
	friend class DbEnv;

public:
	int abort();
	int commit(u_int32_t flags);
	int discard(u_int32_t flags);
	u_int32_t id();
	int prepare(u_int8_t *gid);
	int set_timeout(db_timeout_t timeout, u_int32_t flags);

	virtual DB_TXN *get_DB_TXN()
	{
		return imp_;
	}

	virtual const DB_TXN *get_const_DB_TXN() const
	{
		return imp_;
	}

	static DbTxn* get_DbTxn(DB_TXN *txn)
	{
		return (DbTxn *)txn->api_internal;
	}

	static const DbTxn* get_const_DbTxn(const DB_TXN *txn)
	{
		return (const DbTxn *)txn->api_internal;
	}

	// For internal use only.
	static DbTxn* wrap_DB_TXN(DB_TXN *txn);

private:
	DB_TXN *imp_;

	// We can add data to this class if needed
	// since it is implemented via a pointer.
	// (see comment at top)

	// Note: use DbEnv::txn_begin() to get pointers to a DbTxn,
	// and call DbTxn::abort() or DbTxn::commit rather than
	// delete to release them.
	//
	DbTxn();
	// For internal use only.
	DbTxn(DB_TXN *txn);
	virtual ~DbTxn();

	// no copying
	DbTxn(const DbTxn &);
	void operator = (const DbTxn &);
};

//
// A chunk of data, maybe a key or value.
//
class _exported Dbt : private DBT
{
	friend class Db;
	friend class Dbc;
	friend class DbEnv;
	friend class DbLogc;
	friend class DbSequence;

public:
	// key/data
	void *get_data() const                 { return data; }
	void set_data(void *value)             { data = value; }

	// key/data length
	u_int32_t get_size() const             { return size; }
	void set_size(u_int32_t value)         { size = value; }

	// RO: length of user buffer.
	u_int32_t get_ulen() const             { return ulen; }
	void set_ulen(u_int32_t value)         { ulen = value; }

	// RO: get/put record length.
	u_int32_t get_dlen() const             { return dlen; }
	void set_dlen(u_int32_t value)         { dlen = value; }

	// RO: get/put record offset.
	u_int32_t get_doff() const             { return doff; }
	void set_doff(u_int32_t value)         { doff = value; }

	// flags
	u_int32_t get_flags() const            { return flags; }
	void set_flags(u_int32_t value)        { flags = value; }

	// Conversion functions
	DBT *get_DBT()                         { return (DBT *)this; }
	const DBT *get_const_DBT() const       { return (const DBT *)this; }

	static Dbt* get_Dbt(DBT *dbt)          { return (Dbt *)dbt; }
	static const Dbt* get_const_Dbt(const DBT *dbt)
					       { return (const Dbt *)dbt; }

	Dbt(void *data, u_int32_t size);
	Dbt();
	~Dbt();
	Dbt(const Dbt &);
	Dbt &operator = (const Dbt &);

private:
	// Note: no extra data appears in this class (other than
	// inherited from DBT) since we need DBT and Dbt objects
	// to have interchangable pointers.
	//
	// When subclassing this class, remember that callback
	// methods like bt_compare, bt_prefix, dup_compare may
	// internally manufacture DBT objects (which later are
	// cast to Dbt), so such callbacks might receive objects
	// not of your subclassed type.
};

////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// multiple key/data/reco iterator classes
//

// DbMultipleIterator is a shared private base class for the three types
// of bulk-return Iterator;  it should never be instantiated directly,
// but it handles the functionality shared by its subclasses.
class _exported DbMultipleIterator
{
public:
	DbMultipleIterator(const Dbt &dbt);
protected:
	u_int8_t *data_;
	u_int32_t *p_;
};

class _exported DbMultipleKeyDataIterator : private DbMultipleIterator
{
public:
	DbMultipleKeyDataIterator(const Dbt &dbt) : DbMultipleIterator(dbt) {}
	bool next(Dbt &key, Dbt &data);
};

class _exported DbMultipleRecnoDataIterator : private DbMultipleIterator
{
public:
	DbMultipleRecnoDataIterator(const Dbt &dbt) : DbMultipleIterator(dbt) {}
	bool next(db_recno_t &recno, Dbt &data);
};

class _exported DbMultipleDataIterator : private DbMultipleIterator
{
public:
	DbMultipleDataIterator(const Dbt &dbt) : DbMultipleIterator(dbt) {}
	bool next(Dbt &data);
};

////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Exception classes
//

// Almost any error in the DB library throws a DbException.
// Every exception should be considered an abnormality
// (e.g. bug, misuse of DB, file system error).
//
class _exported DbException : public __DB_STD(exception)
{
public:
	virtual ~DbException() throw();
	DbException(int err);
	DbException(const char *description);
	DbException(const char *description, int err);
	DbException(const char *prefix, const char *description, int err);
	int get_errno() const;
	virtual const char *what() const throw();
	DbEnv *get_env() const;
	void set_env(DbEnv *env);

	DbException(const DbException &);
	DbException &operator = (const DbException &);

private:
	void describe(const char *prefix, const char *description);

	char *what_;
	int err_;                   // errno
	DbEnv *env_;
};

//
// A specific sort of exception that occurs when
// an operation is aborted to resolve a deadlock.
//
class _exported DbDeadlockException : public DbException
{
public:
	virtual ~DbDeadlockException() throw();
	DbDeadlockException(const char *description);

	DbDeadlockException(const DbDeadlockException &);
	DbDeadlockException &operator = (const DbDeadlockException &);
};

//
// A specific sort of exception that occurs when
// a lock is not granted, e.g. by lock_get or lock_vec.
// Note that the Dbt is only live as long as the Dbt used
// in the offending call.
//
class _exported DbLockNotGrantedException : public DbException
{
public:
	virtual ~DbLockNotGrantedException() throw();
	DbLockNotGrantedException(const char *prefix, db_lockop_t op,
	    db_lockmode_t mode, const Dbt *obj, const DbLock lock, int index);
	DbLockNotGrantedException(const char *description);

	DbLockNotGrantedException(const DbLockNotGrantedException &);
	DbLockNotGrantedException &operator =
	    (const DbLockNotGrantedException &);

	db_lockop_t get_op() const;
	db_lockmode_t get_mode() const;
	const Dbt* get_obj() const;
	DbLock *get_lock() const;
	int get_index() const;

private:
	db_lockop_t op_;
	db_lockmode_t mode_;
	const Dbt *obj_;
	DbLock *lock_;
	int index_;
};

//
// A specific sort of exception that occurs when
// user declared memory is insufficient in a Dbt.
//
class _exported DbMemoryException : public DbException
{
public:
	virtual ~DbMemoryException() throw();
	DbMemoryException(Dbt *dbt);
	DbMemoryException(const char *prefix, Dbt *dbt);

	DbMemoryException(const DbMemoryException &);
	DbMemoryException &operator = (const DbMemoryException &);

	Dbt *get_dbt() const;
private:
	Dbt *dbt_;
};

//
// A specific sort of exception that occurs when
// recovery is required before continuing DB activity.
//
class _exported DbRunRecoveryException : public DbException
{
public:
	virtual ~DbRunRecoveryException() throw();
	DbRunRecoveryException(const char *description);

	DbRunRecoveryException(const DbRunRecoveryException &);
	DbRunRecoveryException &operator = (const DbRunRecoveryException &);
};
#endif /* !_DB_CXX_H_ */