Adapter that wraps a stream-based reader with a decompression stream to read records from a compressed data stream. More...

#include <CompressedDataReader.hpp>

Inheritance diagram for CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType >:

Public Member Functions
	CompressedDataReader (std::istream &is)
	Constructs a `CompressedDataReader` instance reading from the input stream is. More...

CompressedDataReader &	read (DataType &obj, bool overwrite=true)
	Reads the next data record into obj. More...

CompressedDataReader &	read (std::size_t idx, DataType &obj, bool overwrite=true)
	Reads the data record at index idx into obj. More...

CompressedDataReader &	skip ()
	Skips the next data record. More...

bool	hasMoreData ()
	Tells whether more records are available. More...

std::size_t	getRecordIndex () const
	Returns the index of the current data record. More...

void	setRecordIndex (std::size_t idx)
	Sets the index of the next data record to be read. More...

std::size_t	getNumRecords ()
	Returns the total number of records in the input stream. More...

	operator const void * () const
	Returns a non-zero value if the reader is in a good state, and zero otherwise. More...

bool	operator! () const
	Tells whether the reader is in a bad state. More...

void	close ()
	Closes the wrapped reader and the decompression stream. More...

Public Member Functions inherited from CDPL::Base::DataReader< typename ReaderImpl::DataType >
virtual DataReader &	read (DataType &obj, bool overwrite=true)=0
	Reads the data record at the current record index and stores the read data in obj. More...

virtual DataReader &	read (std::size_t idx, DataType &obj, bool overwrite=true)=0
	Reads the data record at index idx and stores the read data in obj. More...

Public Member Functions inherited from CDPL::Base::DataIOBase
std::size_t	registerIOCallback (const IOCallbackFunction &func)
	Registers an I/O callback target function. More...

void	unregisterIOCallback (std::size_t id)
	Unregisters the I/O callback function specified by id. More...

void	invokeIOCallbacks (double progress) const
	Invokes all registered I/O callback functions with the argument `*this`. More...

void	clearIOCallbacks ()
	Clears all registered I/O callback functions. More...

Public Member Functions inherited from CDPL::Base::ControlParameterContainer
std::size_t	getNumParameters () const
	Returns the number of container entries. More...

template<typename T >
void	setParameter (const LookupKey &key, T &&val)
	Sets the value of the control-parameter specified by key to val. More...

const Any &	getParameter (const LookupKey &key, bool throw_=false, bool local=false) const
	Returns the value of the control-parameter specified by key. More...

template<typename T >
const T &	getParameter (const LookupKey &key, bool local=false) const
	Returns the value of the control-parameter specified by key as a `const` reference to an object of type T. More...

template<typename T >
const T &	getParameterOrDefault (const LookupKey &key, const T &def_val, bool local=false) const
	Returns the value of the control-parameter specified by key as a `const` reference to an object of type T, or the default value def_val if a stored value does not exist. More...

bool	removeParameter (const LookupKey &key)
	Removes the entry for the control-parameter specified by key. More...

void	clearParameters ()
	Erases all container entries. More...

bool	isParameterSet (const LookupKey &key, bool local=false) const
	Tells whether or not a value has been assigned to the control-parameter specified by key. More...

void	addParameters (const ControlParameterContainer &cntnr)
	Adds the control-parameter value entries in the `ControlParameterContainer` instance cntnr. More...

void	copyParameters (const ControlParameterContainer &cntnr)
	Replaces the current set of properties by a copy of the entries in cntnr. More...

ConstParameterIterator	getParametersBegin () const
	Returns a constant iterator pointing to the beginning of the entries. More...

ConstParameterIterator	getParametersEnd () const
	Returns a constant iterator pointing to the end of the entries. More...

ConstParameterIterator	begin () const
	Returns a constant iterator pointing to the beginning of the entries. More...

ConstParameterIterator	end () const
	Returns a constant iterator pointing to the end of the entries. More...

void	setParent (const ControlParameterContainer *cntnr)
	Sets or removes the parent control-parameter container used to resolve requests for missing entries. More...

const ControlParameterContainer *	getParent () const
	Returns a pointer to the parent control-parameter container. More...

std::size_t	registerParameterChangedCallback (const ParameterChangedCallbackFunction &func)
	Registers a callback target function that gets invoked when the value of a control-parameter has changed. More...

void	unregisterParameterChangedCallback (std::size_t id)
	Unregisters the callback specified by id. More...

std::size_t	registerParameterRemovedCallback (const ParameterRemovedCallbackFunction &func)
	Registers a callback target function that gets invoked when a control-parameter entry has been removed. More...

void	unregisterParameterRemovedCallback (std::size_t id)
	Unregisters the callback specified by id. More...

std::size_t	registerParentChangedCallback (const ParentChangedCallbackFunction &func)
	Registers a callback target function that gets invoked when the parent container has been changed or was detached. More...

void	unregisterParentChangedCallback (std::size_t id)
	Unregisters the callback specified by id. More...

const ControlParameterContainer &	getParameters () const
	Returns a `const` reference to itself. More...

Additional Inherited Members
Public Types inherited from CDPL::Base::DataReader< typename ReaderImpl::DataType >
typedef typename ReaderImpl::DataType	DataType
	The type of the read data objects. More...

typedef std::shared_ptr< DataReader >	SharedPointer
	A reference-counted smart pointer [SHPTR] for dynamically allocated `DataReader` instances. More...

Public Types inherited from CDPL::Base::DataIOBase
typedef std::function< void(const DataIOBase &, double)>	IOCallbackFunction
	A functor class used to wrap I/O callback target functions. More...

Public Types inherited from CDPL::Base::ControlParameterContainer
typedef ParameterMap::value_type	ParameterEntry
	A Base::LookupKey / Base::Any pair used to store the control-parameter values and associated keys. More...

typedef ParameterMap::const_iterator	ConstParameterIterator
	A constant iterator used to iterate over the control-parameter entries. More...

typedef std::function< void(const LookupKey &, const Any &)>	ParameterChangedCallbackFunction
	A functor class that wraps callback target functions which get invoked when the value of a control-parameter has changed. More...

typedef std::function< void(const LookupKey &)>	ParameterRemovedCallbackFunction
	A functor class that wraps callback target functions which get invoked when a control-parameter entry has been removed. More...

typedef std::function< void()>	ParentChangedCallbackFunction
	A functor class that wraps callback target functions which get invoked when the parent container has been changed or was detached. More...

Protected Member Functions inherited from CDPL::Base::DataReader< typename ReaderImpl::DataType >
DataReader &	operator= (const DataReader &reader)
	Assignment operator. More...

Protected Member Functions inherited from CDPL::Base::DataIOBase
	DataIOBase ()
	Default constructor. More...

	DataIOBase (const DataIOBase &io_base)
	Copy constructor. More...

	~DataIOBase ()
	Destructor. More...

DataIOBase &	operator= (const DataIOBase &io_base)
	Assignment operator. More...

Protected Member Functions inherited from CDPL::Base::ControlParameterContainer
	ControlParameterContainer ()
	Constructs an empty `ControlParameterContainer` instance. More...

	ControlParameterContainer (const ControlParameterContainer &cntnr)
	Constructs a copy of the `ControlParameterContainer` instance cntnr. More...

virtual	~ControlParameterContainer ()
	Destructor. More...

ControlParameterContainer &	operator= (const ControlParameterContainer &cntnr)
	Assignment operator. More...

Detailed Description

template<typename ReaderImpl, typename DecompStream, typename DataType = typename ReaderImpl::DataType>
class CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType >

Adapter that wraps a stream-based reader with a decompression stream to read records from a compressed data stream.

CompressedDataReader is a thin template wrapper around an existing Base::DataReader implementation ReaderImpl. It constructs a decompression stream of type DecompStream around the supplied input stream and forwards all read operations to the inner reader. The reader exposes the standard Base::DataReader interface.

Template Parameters

ReaderImpl	The wrapped reader implementation type.
DecompStream	The decompression stream type to wrap around the input stream.
DataType	The data record type produced by the reader.

Constructor & Destructor Documentation

◆ CompressedDataReader()

template<typename ReaderImpl , typename DecompStream , typename DataType >

CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType >::CompressedDataReader ( std::istream & is )

Constructs a CompressedDataReader instance reading from the input stream is.

Parameters

is	The input stream providing the compressed data.

Member Function Documentation

◆ read() [1/2]

template<typename ReaderImpl , typename DecompStream , typename DataType >

CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType > & CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType >::read	(	DataType &	obj,
		bool	overwrite = `true`
	)

Reads the next data record into obj.

Parameters

obj	The output data object.
overwrite	If `true`, any pre-existing content of obj is replaced; otherwise the new data is merged.

Returns: A reference to itself.

◆ read() [2/2]

template<typename ReaderImpl , typename DecompStream , typename DataType >

CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType > & CDPL::Util::CompressedDataReader< ReaderImpl, DecompStream, DataType >::read	(	std::size_t	idx,
		DataType &	obj,
		bool	overwrite = `true`
	)

Reads the data record at index idx into obj.

Parameters

idx	The zero-based index of the record to read.
obj	The output data object.
overwrite	If `true`, any pre-existing content of obj is replaced; otherwise the new data is merged.