Private data for the QCassandra class. More...

#include <QCassandraPrivate.h>

Collaboration diagram for QtCassandra::QCassandraPrivate:

Public Member Functions
	QCassandraPrivate (QCassandra *parent)
	Initialize the private QCassandra object.
	~QCassandraPrivate ()
	Clean up the object.
QString	clusterName () const
	Retrieve the name of the cluster.
bool	connect (const QString &host, int port)
	Connect to the Cassandra server.
void	contexts () const
	Go through the list of contexts and build a list of such.
void	createContext (const QCassandraContext &context)
	Create a new context.
void	createTable (const QCassandraTable *table)
	Create a table in the Cassandra server.
void	disconnect ()
	Disconnect from the Cassandra server.
void	dropContext (const QCassandraContext &context)
	Drop an existing context.
void	dropTable (const QString &table_name)
	Drop a table from the Cassandra server.
int32_t	getCellCount (const QString &table_name, const QByteArray &row_key, const QCassandraColumnPredicate &column_predicate)
	Get a slice of columns from the Cassandra database.
void	getColumnSlice (QCassandraTable &table, const QByteArray &row_key, const QCassandraColumnPredicate &column_predicate)
	Get a slice of columns from the Cassandra database.
uint32_t	getRowSlices (QCassandraTable &table, const QCassandraRowPredicate &row_predicate)
	This function retrieves a set of rows.
void	getValue (const QString &table_name, const QByteArray &row_key, const QByteArray &column_key, QCassandraValue &value)
	Get a value from the Cassandra database.
void	insertValue (const QString &table_name, const QByteArray &row_key, const QByteArray &column_key, const QCassandraValue &value)
	Insert a value in the Cassandra database.
bool	isConnected () const
	Check whether we're connected.
QString	protocolVersion () const
	Retrieve the version of the protocol.
void	remove (const QString &table_name, const QByteArray &row_key, const QByteArray &column_key, int64_t timestamp, consistency_level_t consistency_level)
	Remove a cell from the Cassandra database.
void	setContext (const QString &context)
	Set the context keyspace name.
void	truncateTable (const QCassandraTable *table)
	Truncate a table in the Cassandra server.
void	updateContext (const QCassandraContext &context)
	Update an existing context.
void	updateTable (const QCassandraTable *table)
	Update a table in the Cassandra server.
Private Member Functions
	QCassandraPrivate (const QCassandraPrivate &)
	Forbid the copy operator.
void	mustBeConnected () const throw (std::runtime_error)
	Check that we're connected.
Private Attributes
boost::shared_ptr < org::apache::cassandra::CassandraClient >	f_client
	Define a client object.
QCassandra *	f_parent
	The pointer to the QCassandra object.
boost::shared_ptr < apache::thrift::protocol::TProtocol >	f_protocol
	The protocol between us and the Cassandra server.
boost::shared_ptr < apache::thrift::transport::TTransport >	f_socket
	The socket used to connect to the Cassandra server.
boost::shared_ptr < apache::thrift::transport::TTransport >	f_transport
	The transport handler.

Detailed Description

This class handles such things as the connection to the Cassandra server and hiding all the thrift definitions.

Definition at line 48 of file QCassandraPrivate.h.

Constructor & Destructor Documentation

QtCassandra::QCassandraPrivate::QCassandraPrivate ( QCassandra * parent )

This function initialize the QCassandra private object.

Parameters:

[in] parent The parent pointer (i.e. QCassandra object)

Definition at line 117 of file QCassandraPrivate.cpp.

QtCassandra::QCassandraPrivate::~QCassandraPrivate ( )

This function makes sure we clean up after ourselves.

Definition at line 142 of file QCassandraPrivate.cpp.

References disconnect().

QtCassandra::QCassandraPrivate::QCassandraPrivate ( const QCassandraPrivate & ) [inline, private]

By default we forbid the copy operator of the QCassandraPrivate class.

The class includes a network connection and we really do not want to have to clone such a thing.

Note that most of the objects do not define the copy operator since they are QObject's and these are already not copyable.

Definition at line 81 of file QCassandraPrivate.h.

Member Function Documentation

QString QtCassandra::QCassandraPrivate::clusterName ( ) const

This function sends a message to the Cassandra server to determine the name of the cluster.

Returns:: The name of the cluster.

Definition at line 262 of file QCassandraPrivate.cpp.

References f_client, and mustBeConnected().

bool QtCassandra::QCassandraPrivate::connect	(	const QString &	host,
		int	port
	)

This function needs to be called before most of the others.

It is not mentioned on each other function that if the connection is not up then an exception is generated. It will be noted, however, that a connection is required for the function to work.

Note that the main QCassandra object is responsible to test whether the connection valid (isConnected()) and to capture exceptions that should be replaced by a boolean return values and similar approaches.

In the early days expect to see exceptions coming up until we take care of them all.

Note that this function first turns off the existing connection if there is one.

Parameters:

[in]	host	The host of the Cassandra server.
[in]	port	The port of the Cassandra server.

Returns:: true when the server connected, false otherwise

See also:: isConnected(); disconnect()

Definition at line 173 of file QCassandraPrivate.cpp.

References disconnect(), f_client, f_protocol, f_socket, and f_transport.

void QtCassandra::QCassandraPrivate::contexts ( ) const

This function creates a list of QCassandraContexts and returns the result.

The function retrieves all the keyspaces from Cassandra, transforms them in QCassandraContext objects, and save the result in a QCassandraContexts map indexed by name and returns that object.

The QCassandra object is responsible for caching the result. The result should not change until we create a new table although if another process on another machine changes the Cassandra cluster structure, it will not be seen until the cache is cleared.

Definition at line 313 of file QCassandraPrivate.cpp.

References QtCassandra::QCassandra::context(), f_client, f_parent, and mustBeConnected().

void QtCassandra::QCassandraPrivate::createContext ( const QCassandraContext & context )

This function creates a new context. Trying to create a context with the name of an existing context will fail. Use the update function instead.

The new context identifier is not returned. I'm not too sure what you could do with it anyway since no function make use of it.

At this time, it looks like you cannot include an array of tables in the context or the create function fails.

Parameters:

[in] context The context definition used to create the new context.

See also:: updateContext()

Definition at line 345 of file QCassandraPrivate.cpp.

References f_client, mustBeConnected(), and QtCassandra::QCassandraContext::prepareContextDefinition().

Referenced by QtCassandra::QCassandraContext::create().

void QtCassandra::QCassandraPrivate::createTable ( const QCassandraTable * table )

This function creates a table in the cassandra server transforming a QCassandraTable in a table definition (CfDef) and then calling the system_add_column_family() function.

Parameters:

[in] table The table to be created.

Definition at line 400 of file QCassandraPrivate.cpp.

References f_client, mustBeConnected(), and QtCassandra::QCassandraTable::prepareTableDefinition().

Referenced by QtCassandra::QCassandraContext::createTable().

void QtCassandra::QCassandraPrivate::disconnect ( )

This function destroys the connection of the Cassandra server.

After calling this function, any other function that require a connection will fail.

Definition at line 211 of file QCassandraPrivate.cpp.

References f_client, f_protocol, f_socket, and f_transport.

Referenced by connect(), and ~QCassandraPrivate().

void QtCassandra::QCassandraPrivate::dropContext ( const QCassandraContext & context )

This function drops an existing context. After this call, do not try to access the context again until you re-create it.

Parameters:

[in] context The context to drop from the attached Cassandra cluster.

See also:: createContext()

Definition at line 384 of file QCassandraPrivate.cpp.

References QtCassandra::QCassandra::clearCurrentContextIf(), QtCassandra::QCassandraContext::contextName(), f_client, f_parent, and mustBeConnected().

Referenced by QtCassandra::QCassandraContext::drop().

void QtCassandra::QCassandraPrivate::dropTable ( const QString & table_name )

This function drops the named table from the cassandra server.

Parameters:

[in] table_name The name of the table to be dropped.

Definition at line 430 of file QCassandraPrivate.cpp.

References f_client, and mustBeConnected().

Referenced by QtCassandra::QCassandraContext::dropTable().

int32_t QtCassandra::QCassandraPrivate::getCellCount	(	const QString &	table_name,
		const QByteArray &	row_key,
		const QCassandraColumnPredicate &	column_predicate
	)

This function retrieves a slice from the Cassandra database. A slice is an array of column from a specific row.

The result is passed to a QCassndraTable which is expected to save it as a set of rows, cells, and values.

Parameters:

[in]	table_name	Name of the table where the cell counting is processed.
[in]	row_key	The key used to identify the row.
[in]	column_predicate	The predicate defining the name of the columns to return.

Returns:: The number of cells (Columns) found using the specified predicate.

Definition at line 578 of file QCassandraPrivate.cpp.

References QtCassandra::CONSISTENCY_LEVEL_DEFAULT, QtCassandra::QCassandraColumnPredicate::consistencyLevel(), QtCassandra::QCassandra::defaultConsistencyLevel(), f_client, f_parent, mustBeConnected(), and QtCassandra::QCassandraColumnPredicate::toPredicate().

Referenced by QtCassandra::QCassandraContext::getCellCount().

void QtCassandra::QCassandraPrivate::getColumnSlice	(	QCassandraTable &	table,
		const QByteArray &	row_key,
		const QCassandraColumnPredicate &	column_predicate
	)

This function retrieves a slice from the Cassandra database. A slice is an array of column from a specific row.

The result is passed to a QCassndraTable which is expected to save it as a set of rows, cells, and values.

Parameters:

[in,out]	table	The table where values found get inserted.
[in]	row_key	The key used to identify the row.
[in]	column_predicate	The predicate defining the name of the columns to return.

Definition at line 615 of file QCassandraPrivate.cpp.

References QtCassandra::QCassandraTable::assignRow(), QtCassandra::QCassandraValue::assignTimestamp(), QtCassandra::CONSISTENCY_LEVEL_DEFAULT, QtCassandra::QCassandraColumnPredicate::consistencyLevel(), QtCassandra::QCassandra::defaultConsistencyLevel(), f_client, f_parent, mustBeConnected(), QtCassandra::QCassandraValue::setBinaryValue(), QtCassandra::QCassandraValue::setTtl(), QtCassandra::QCassandraTable::tableName(), and QtCassandra::QCassandraColumnPredicate::toPredicate().

Referenced by QtCassandra::QCassandraContext::getColumnSlice().

uint32_t QtCassandra::QCassandraPrivate::getRowSlices	(	QCassandraTable &	table,
		const QCassandraRowPredicate &	row_predicate
	)

This function retrieves a set of rows filtered by the specified predicate and return the result in the corresponding table.

Parameters:

[in,out]	table	The table requesting the row slices.
[in]	row_predicate	The predicate to select rows and columns.

Returns:: The number of rows read from the Cassandra server.

Definition at line 704 of file QCassandraPrivate.cpp.

References QtCassandra::QCassandraTable::assignRow(), QtCassandra::QCassandraValue::assignTimestamp(), QtCassandra::QCassandraRowPredicate::columnPredicate(), QtCassandra::CONSISTENCY_LEVEL_DEFAULT, QtCassandra::QCassandra::defaultConsistencyLevel(), f_client, f_parent, mustBeConnected(), QtCassandra::QCassandraValue::setBinaryValue(), QtCassandra::QCassandraValue::setTtl(), QtCassandra::QCassandraTable::tableName(), and QtCassandra::QCassandraRowPredicate::toPredicate().

Referenced by QtCassandra::QCassandraContext::getRowSlices().

void QtCassandra::QCassandraPrivate::getValue	(	const QString &	table_name,
		const QByteArray &	row_key,
		const QByteArray &	column_key,
		QCassandraValue &	value
	)

This function retrieves a value from the Cassandra database.

It is retrieve from the current context, table_name, row_key, and column_key.

Parameters:

[in]	table_name	Name of the table where the value is inserted.
[in]	row_key	The key used to identify the row.
[in]	column_key	The key used to identify the column.
[out]	value	The new value of the cell.

Definition at line 520 of file QCassandraPrivate.cpp.

References QtCassandra::QCassandraValue::assignTimestamp(), QtCassandra::CONSISTENCY_LEVEL_DEFAULT, QtCassandra::QCassandraValue::consistencyLevel(), QtCassandra::QCassandra::defaultConsistencyLevel(), f_client, f_parent, mustBeConnected(), QtCassandra::QCassandraValue::setBinaryValue(), QtCassandra::QCassandraValue::setNullValue(), and QtCassandra::QCassandraValue::setTtl().

Referenced by QtCassandra::QCassandraContext::getValue().

void QtCassandra::QCassandraPrivate::insertValue	(	const QString &	table_name,
		const QByteArray &	row_key,
		const QByteArray &	column_key,
		const QCassandraValue &	value
	)

This function insert the specified value in the Cassandra database.

It is saved in the current context, table_name, row_key, and column_key.

Parameters:

[in]	table_name	Name of the table where the value is inserted.
[in]	row_key	The key used to identify the row.
[in]	column_key	The key used to identify the column.
[in]	value	The new value of the cell.

Definition at line 462 of file QCassandraPrivate.cpp.

Referenced by QtCassandra::QCassandraContext::insertValue().

bool QtCassandra::QCassandraPrivate::isConnected ( ) const

This checks whether an f_client point exists.

Note:: To test whether the actual TCP/IP connection is up we'll want to have some NOOP function (i.e. describe_cluster_name()).

Returns:: true if the server is connected

Definition at line 233 of file QCassandraPrivate.cpp.

References f_client.

Referenced by mustBeConnected().

void QtCassandra::QCassandraPrivate::mustBeConnected ( ) const throw (std::runtime_error) [private]

This function verifies that the cassandra server is connected (as in the connect() function was called ans succeeded. If not connected, then an exception is raised.

Exceptions:

std::runtime_error This function raises an exception if the QCassandraPrivate object is not currently connected to a Cassandra server.

Definition at line 248 of file QCassandraPrivate.cpp.

References isConnected().

Referenced by clusterName(), contexts(), createContext(), createTable(), dropContext(), dropTable(), getCellCount(), getColumnSlice(), getRowSlices(), getValue(), insertValue(), protocolVersion(), remove(), setContext(), truncateTable(), updateContext(), and updateTable().

QString QtCassandra::QCassandraPrivate::protocolVersion ( ) const

This function sends a message to the Cassandra server to determine the version of the protocol.

Returns:: The version of the protocol.

Definition at line 277 of file QCassandraPrivate.cpp.

References f_client, and mustBeConnected().

void QtCassandra::QCassandraPrivate::remove	(	const QString &	table_name,
		const QByteArray &	row_key,
		const QByteArray &	column_key,
		int64_t	timestamp,
		consistency_level_t	consistency_level
	)

This function calls the Cassandra server to remove a cell in the Cassandra database.

Parameters:

[in]	table_name	The name of the column where the row is defined.
[in]	row_key	The row in which the cell is to be removed.
[in]	column_key	The cell to be removed, may be empty to remove all the cells.
[in]	timestamp	The time when the key to be removed was created.
[in]	consistency_level	The consistency level to use to remove this cell.

Definition at line 672 of file QCassandraPrivate.cpp.

References QtCassandra::CONSISTENCY_LEVEL_DEFAULT, QtCassandra::QCassandra::defaultConsistencyLevel(), f_client, f_parent, and mustBeConnected().

Referenced by QtCassandra::QCassandraContext::remove().

void QtCassandra::QCassandraPrivate::setContext ( const QString & context_name )

The Cassandra database system reacts to commands in a specific keyspace which is managed like a context. This context must be specified before other functions are called or those other functions will fail.

Parameters:

[in] context_name The name of the context to use as the current context.

Definition at line 293 of file QCassandraPrivate.cpp.

References f_client, and mustBeConnected().

void QtCassandra::QCassandraPrivate::truncateTable ( const QCassandraTable * table )

This function truncates (i.e. removes all the rows and their data) a table from the cassandra server.

Parameters:

[in] table The table to be created.

Definition at line 444 of file QCassandraPrivate.cpp.

References f_client, mustBeConnected(), and QtCassandra::QCassandraTable::tableName().

Referenced by QtCassandra::QCassandraContext::truncateTable().

void QtCassandra::QCassandraPrivate::updateContext ( const QCassandraContext & context )

This function updates an existing context. Some options may not be updateable.

The context should be one that you loaded from the cluster to be sure that you start with the right data.

Parameters:

[in] context The context to update in the attached Cassandra cluster.

See also:: createContext()

Definition at line 366 of file QCassandraPrivate.cpp.

References f_client, mustBeConnected(), and QtCassandra::QCassandraContext::prepareContextDefinition().

Referenced by QtCassandra::QCassandraContext::update().

void QtCassandra::QCassandraPrivate::updateTable ( const QCassandraTable * table )

This function updates a table int the cassandra server.

Parameters:

[in] table The table to be updated.

Definition at line 415 of file QCassandraPrivate.cpp.

References f_client, mustBeConnected(), and QtCassandra::QCassandraTable::prepareTableDefinition().

Referenced by QtCassandra::QCassandraContext::updateTable().

Member Data Documentation

QtCassandra::QCassandraPrivate::f_client [private]

The client object is what we use everywhere to communicate with the Cassandra server. It is a Cassandra Client object that knows how to convert the Cassandra specific messages and send them over the transport object.

To create a client, we need to create a socket, a transport and a protocol. If any one of those steps fails, then you cannot communicate with the Cassandra server.

The main raison for failure is an invalid IP/port combinaison or your Cassandra server isn't running.

Definition at line 90 of file QCassandraPrivate.h.

Referenced by clusterName(), connect(), contexts(), createContext(), createTable(), disconnect(), dropContext(), dropTable(), getCellCount(), getColumnSlice(), getRowSlices(), getValue(), insertValue(), isConnected(), protocolVersion(), remove(), setContext(), truncateTable(), updateContext(), and updateTable().

QtCassandra::QCassandraPrivate::f_parent [private]

This variable member holds the QCassandra object pointer. This QCassandra object owns the QCassandraPrivate object (it's a 1 to 1.) This is why this pointer is a bare pointer. When the QCassandra goes, so does the QCassandraPriavet. And if the QCassandraPrivate goes, that's because the QCassandra is going.

Definition at line 86 of file QCassandraPrivate.h.

Referenced by contexts(), dropContext(), getCellCount(), getColumnSlice(), getRowSlices(), getValue(), insertValue(), and remove().

QtCassandra::QCassandraPrivate::f_protocol [private]

This object defines the protocol. In other words, it knows how to send and receive messages (i.e. header, footer, etc.)

Definition at line 89 of file QCassandraPrivate.h.

Referenced by connect(), and disconnect().

QtCassandra::QCassandraPrivate::f_socket [private]

This pointer holds a Thrift socket used to communicate with the Cassandra server.

At our level we just provide the socket to the framed transport. How it is being used is Thrift responsibility.

It is setup with the IP address and port that one can use to access the Cassandra server.

Definition at line 87 of file QCassandraPrivate.h.

Referenced by connect(), and disconnect().

QtCassandra::QCassandraPrivate::f_transport [private]

The transport object of the Thrift system to manage the data being send and received from the Cassandra server.

The socket is attached to the transport system.

Definition at line 88 of file QCassandraPrivate.h.

Referenced by connect(), and disconnect().

The documentation for this class was generated from the following files:

/home/alexis/m2osw/sources/freeware/snapwebsites/libQtCassandra/src/QCassandraPrivate.h
/home/alexis/m2osw/sources/freeware/snapwebsites/libQtCassandra/src/QCassandraPrivate.cpp

QtCassandra::QCassandraPrivate Class Reference

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation