RWDBRow Class Reference

An ordered collection of RWDBValue instances. More...

#include <rw/db/row.h>

Inheritance diagram for RWDBRow:

Public Member Functions
	RWDBRow ()
	RWDBRow (const RWDBRow &rvalue)
virtual	~RWDBRow ()
virtual void	append (const RWDBValue &value)
RWspace	binaryStoreSize () const
virtual void	clearAndDestroy ()
virtual int	compareTo (const RWCollectable *c) const
virtual size_t	entries () const
virtual unsigned	hash () const
virtual RWClassID	isA () const
virtual bool	isEqual (const RWCollectable *c) const
virtual RWCollectable *	newSpecies () const
RWDBRow &	operator= (const RWDBRow &rvalue)
RWDBValue &	operator[] (size_t index) const
virtual void	restoreGuts (RWFile &file)
virtual void	restoreGuts (RWvistream &stream)
virtual void	saveGuts (RWFile &file) const
virtual void	saveGuts (RWvostream &stream) const
Public Member Functions inherited from RWCollectable
virtual	~RWCollectable ()
RWspace	recursiveStoreSize () const
RWStringID	stringID () const

Additional Inherited Members
Static Public Member Functions inherited from RWCollectable
static RWClassID	classID (const RWStringID &name)
static RWClassID	classIsA ()
static bool	isAtom (RWClassID id)
static RWspace	nilStoreSize ()

Detailed Description

RWDBRow is an ordered collection of RWDBValue objects. RWDBRow is a relatively low level construct used by the DB Interface Module to store a row of data on its way to or from the database. It is visible to applications for two reasons:

• An RWDBRow is a single row of an RWDBMemTable.
• Some applications may want to manage raw data without knowing anything about its structure. RWDBRow can be used as a container in these cases.

The only semantics that RWDBRow adds to RWCollectable are:

• The index operator operator[]() return RWDBValue&, rather than RWCollectable*&.
• The destructor deallocates the contents of the RWDBRow by calling clearAndDestroy().

RWDBRow is designed around the Interface/Implementation paradigm. An RWDBRow instance is an interface to a reference-counted implementation; copy constructors and assignment operators produce additional references to a shared implementation.

Synopsis

#include <rw/db/row.h>

RWDBRow& r = myMemTable[i];

Constructor & Destructor Documentation

RWDBRow::RWDBRow

(

)

The default constructor produces an empty RWDBRow.

RWDBRow::RWDBRow

(

const RWDBRow &

rvalue

)

Copy constructor. The created RWDBRow shares an implementation with rvalue.

virtual RWDBRow::~RWDBRow ( )

virtual

The default destructor.

Member Function Documentation

virtual void RWDBRow::append ( const RWDBValue &  value )

virtual

Appends value to self.

RWspace RWDBRow::binaryStoreSize ( ) const

virtual

Returns the number of bytes required to store self.

Reimplemented from RWCollectable.

virtual void RWDBRow::clearAndDestroy ( )

virtual

Removes all values from the collection and deletes them.

virtual int RWDBRow::compareTo ( const RWCollectable *  c ) const

virtual

If c points to an RWDBRow, this method returns:

• 0, if self and c share the same implementation
• >0, if self has length greater than c
• <0, if c has length greater than self

If self and c do not share the same implementation and both have the same length, compares each RWDBValue in self with each value in c. Returns 0 if all values compare equal, otherwise returns the result of the first comparison that does not return 0.

If c does not point to an RWDBRow, throws an std::bad_cast exception.

As a precondition, c is tested to determine if it is a null pointer. If null, the method asserts in debug mode, and throws RWInternalErr in optimized builds.

Reimplemented from RWCollectable.

virtual size_t RWDBRow::entries ( ) const

virtual

Returns the total number of values in the collection.

virtual unsigned RWDBRow::hash ( ) const

virtual

Returns a hash value for use in collection classes.

Reimplemented from RWCollectable.

virtual RWClassID RWDBRow::isA ( ) const

virtual

Redefined from class RWCollectable. Returns __RWDBROW.

Reimplemented from RWCollectable.

virtual bool RWDBRow::isEqual ( const RWCollectable *  c ) const

virtual

Returns true if compareTo(c) == 0, otherwise returns false.

Reimplemented from RWCollectable.

virtual RWCollectable* RWDBRow::newSpecies ( ) const

virtual

Allocates a new object off the heap of the same type as self and returns a pointer to it. You are responsible for deleting the object when done with it.

Reimplemented from RWCollectable.

RWDBRow& RWDBRow::operator=

(

const RWDBRow &

rvalue

)

Assignment operator. Returns reference to self which shares an implementation with rvalue.

RWDBValue& RWDBRow::operator[]

(

size_t

index

)

const

Returns a reference to the RWDBValue at position index in the collection. Throws an exception of type RWBoundsErr if index is out of range.

virtual void RWDBRow::restoreGuts ( RWFile &  file )

virtual

Reads file, replacing the contents of self.

Reimplemented from RWCollectable.

virtual void RWDBRow::restoreGuts ( RWvistream &  stream )

virtual

Reads stream, replacing the contents of self.

Reimplemented from RWCollectable.

virtual void RWDBRow::saveGuts ( RWFile &  file ) const

virtual

Writes the contents of self to file.

Reimplemented from RWCollectable.

virtual void RWDBRow::saveGuts ( RWvostream &  stream ) const

virtual

Writes the contents of self to stream.

Reimplemented from RWCollectable.