CDPL.Grid.DRegularGridSetReaderBase Class Reference

An interface for reading data objects of type Grid.DRegularGridSet from an arbitrary data source. More...

Inheritance diagram for CDPL.Grid.DRegularGridSetReaderBase:

Public Member Functions
None	__init__ ()
	Initializes the DRegularGridSetReaderBase instance.
DRegularGridSetReaderBase	read (DRegularGridSet grid_set, bool overwrite=True)
	Reads the data record at the current record index and stores the read data in grid_set. More...
DRegularGridSetReaderBase	read (int idx, DRegularGridSet grid_set, bool overwrite=True)
	Reads the data record at index idx and stores the read data in grid_set. More...
DRegularGridSetReaderBase	skip ()
	Skips the data record at the current record index. More...
bool	hasMoreData ()
	Tells if there are any data records left to read. More...
int	getRecordIndex ()
	Returns the index of the current data record. More...
None	setRecordIndex (int idx)
	Sets the index of the current data record to idx. More...
int	getNumRecords ()
	Returns the total number of available data records. More...
None	close ()
	Performs a reader specific shutdown operation (if required). More...
bool	__nonzero__ ()
bool	__bool__ ()
Public Member Functions inherited from CDPL.Base.DataIOBase
int	registerIOCallback (VoidDataIOBaseFunctor func)
	Registers an I/O callback target function. More...
None	unregisterIOCallback (int id)
	Unregisters the I/O callback function specified by id. More...
None	invokeIOCallbacks (float progress)
	Invokes all registered I/O callback functions with the argument self. More...
None	clearIOCallbacks ()
	Clears all registered I/O callback functions.
Public Member Functions inherited from CDPL.Base.ControlParameterContainer
None	setParameter (LookupKey key, Any value)
bool	removeParameter (LookupKey key)
	Removes the entry for the control-parameter specified by key. More...
Any	getParameter (LookupKey key, bool throw_=False, bool local=False)
	Returns the value of the control-parameter specified by key. More...
Any	getParameterOrDefault (LookupKey key, Any def_value, bool local=False)
bool	isParameterSet (LookupKey key, bool local=False)
	Tells whether or not a value has been assigned to the control-parameter specified by key. More...
None	clearParameters ()
	Erases all container entries. More...
None	addParameters (ControlParameterContainer cntnr)
	Adds the control-parameter value entries in the ControlParameterContainer instance cntnr. More...
None	copyParameters (ControlParameterContainer cntnr)
	Replaces the current set of properties by a copy of the entries in cntnr. More...
int	getNumParameters ()
	Returns the number of container entries. More...
int	registerParameterChangedCallback (VoidLookupKeyAnyFunctor func)
	Registers a callback target function that gets invoked when the value of a control-parameter has changed. More...
None	unregisterParameterChangedCallback (int id)
	Unregisters the callback specified by id. More...
int	registerParameterRemovedCallback (VoidLookupKeyFunctor func)
	Registers a callback target function that gets invoked when a control-parameter entry has been removed. More...
None	unregisterParameterRemovedCallback (int id)
	Unregisters the callback specified by id. More...
int	registerParentChangedCallback (VoidFunctor func)
	Registers a callback target function that gets invoked when the parent container has been changed or was detached. More...
None	unregisterParentChangedCallback (int id)
	Unregisters the callback specified by id. More...
ControlParameterContainer	getParent ()
	Returns a reference to the parent control-parameter container. More...
None	setParent (ControlParameterContainer cntnr)
	Sets or removes the parent control-parameter container used to resolve requests for missing entries. More...
list	getParameterKeys ()
list	getParameterValues ()
list	getParameters ()
	Returns a reference to itself. More...
int	getObjectID ()
	Returns the numeric identifier (ID) of the wrapped C++ class instance. More...
Any	__getitem__ (LookupKey key)
None	__setitem__ (LookupKey key, Any value)
bool	__delitem__ (LookupKey self)
bool	__contains__ (LookupKey self, bool key)
	Returns the result of the membership test operation self in arg1. More...
int	__len__ ()

Properties
	numRecords = property(getNumRecords)
Properties inherited from CDPL.Base.ControlParameterContainer
	objectID = property(getObjectID)
	parent = property(getParent, setParent)
	parameterKeys = property(getParameterKeys)
	parameterValues = property(getParameterValues)
	parameters = property(getParameters)
	numParameters = property(getNumParameters)

Detailed Description

An interface for reading data objects of type Grid.DRegularGridSet from an arbitrary data source.

DRegularGridSetReaderBase is the common interface of classes which read objects of type Grid.DRegularGridSet from some data source (e.g. a file) that provides the data encoded in a particular storage format.

From the DRegularGridSetReaderBase interface point of view, the data source is organized as an array of logical data records. Each record is addressed by a zero-based sequential record index and contains the data for exactly one data object. The total number of available data records (which is equal to the maximum record index plus 1) can be queried by the method getNumRecords().

Similar to low-level file I/O, data records may either be read in a sequential or in a random access manner. For sequential access the method read(grid_set: DRegularGridSet) is provided which will read the data record at the 'current' record index (similar to a file reference). The current record index is accessible by the method getRecordIndex() and can be modified using the method setRecordIndex() (similar to a seek operation).

For reading data records in a random access manner, the method read(std::size_t idx, grid_set: DRegularGridSet) is available. In contrast to the former read() method, this method expects the index of the record to read as the first argument.

If a read() (or skip()) operation was successful, the current record index is updated to point to the record immediately following the just read (or skipped) data record. If an operation fails, the reader instance is set into an error state that can be queried by the special methods bool() and nonzero(). Additionally, a DRegularGridSetReaderBase implementation may decide to throw an exception of type Base.IOError to report the error condition.

Member Function Documentation

read() [1/2]

DRegularGridSetReaderBase CDPL.Grid.DRegularGridSetReaderBase.read	(	DRegularGridSet	grid_set,
		bool	overwrite = True
	)

Reads the data record at the current record index and stores the read data in grid_set.

If the read operation was successful, the record index is incremented by 1.

Parameters

grid_set	The DRegularGridSet object storing the read data.
overwrite	Specifies whether any existing data in grid_set shall be replaced by the newly read data or if the read data should be appended (if supported by the reader and data type).

Returns

self

Exceptions

Base.IOError

if an I/O error occurred.

read() [2/2]

DRegularGridSetReaderBase CDPL.Grid.DRegularGridSetReaderBase.read	(	int	idx,
		DRegularGridSet	grid_set,
		bool	overwrite = True
	)

Reads the data record at index idx and stores the read data in grid_set.

If the read operation was successful, the record index is set to idx + 1.

Parameters

idx	The zero-based index of the data record to read.
grid_set	The DRegularGridSet object storing the read data.
overwrite	Specifies whether any existing data in grid_set shall be replaced by the newly read data or if the read data should be appended (if supported by the reader and data type).

Returns

self

Exceptions

Base.IndexError

if idx is greater or equal to the number of records. Base.IOError if an I/O error occurred.

skip()

DRegularGridSetReaderBase CDPL.Grid.DRegularGridSetReaderBase.skip

(

)

Skips the data record at the current record index.

If the operation was successful, the record index is incremented by 1.

Returns

self

Exceptions

Base.IOError

if an I/O error occurred.

hasMoreData()

bool CDPL.Grid.DRegularGridSetReaderBase.hasMoreData

(

)

Tells if there are any data records left to read.

Returns

True if there are data records left to read, and False otherwise.

Exceptions

Base.IOError

if an I/O error occurred.

getRecordIndex()

int CDPL.Grid.DRegularGridSetReaderBase.getRecordIndex

(

)

Returns the index of the current data record.

Returns

The zero-based index of the current data record.

setRecordIndex()

None CDPL.Grid.DRegularGridSetReaderBase.setRecordIndex

(

int

idx

)

Sets the index of the current data record to idx.

Parameters

idx	The zero-based index of the data record.

Exceptions

Base.IndexError

if idx is greater or equal to the number of available data records. Base.IOError if an I/O error occurred.

getNumRecords()

int CDPL.Grid.DRegularGridSetReaderBase.getNumRecords

(

)

Returns the total number of available data records.

Returns

The total number of available data records.

Exceptions

Base.IOError

if an I/O error occurred.

close()

None CDPL.Grid.DRegularGridSetReaderBase.close

(

)

Performs a reader specific shutdown operation (if required).

Exceptions

Base.IOError

if an I/O error occurred.

__nonzero__()

bool CDPL.Grid.DRegularGridSetReaderBase.__nonzero__

(

)

Returns

__bool__()

bool CDPL.Grid.DRegularGridSetReaderBase.__bool__

(

)

Returns