A named map from keys to values. More...

#include <keyvalue/mngt/DataSet.h>

Classes
struct	Graph
	Simplified dependency graph. More...
struct	Record
	A wrapper around a value::Value. More...
Public Member Functions
	DataSet (const string &name)
	Constructs an empty DataSet with a given name.
string	getName () const
	Gets DataSet's name.
void	add (const string &key, const value::Value &value)
	Adds a key-value pair to the DataSet.
template<typename KeyType >
KeyType::OutputType_ *	find (const KeyType &key) const
	Checks if key can be found.
template<typename KeyType >
KeyType::OutputType_	getValue (const KeyType &key) const
	Gets and processes value associated to a key.
value::Result	process () const
	Processes a DataSet.
template<typename ObjectType >
value::PtrTraits< ObjectType > ::Type_	build () const
	Builds the object defined by this DataSet provided its type.
bool	mustUpdate () const
	Checks if there is need for reprocessing.
Private Types
typedef ::std::map< string, shared_ptr< Record > >	MapType_
typedef MapType_::value_type	ValueType_
Private Member Functions
Graph	getGraph (const string &key, bool start=true) const
	Gets the simplified dependency graph of a key.
Graph	getGraph (shared_ptr< Record > first, const string &key) const
const Processor &	getProcessor () const
	Gets the Processor expected to process this DataSet.
value::Result	process (const Processor &processor) const
	Processes this DataSet by a given Processor.
Private Attributes
string	name_
MapType_	map_
bool	mustUpdate_
value::Result	result_
Friends
friend::std::ostream &	operator<< (::std::ostream &os, const DataSet &dataSet)
	ostream operator<<() for DataSet.

Detailed Description

A named map from keys to values.

Constructor & Destructor Documentation

DataSet ( const string & name ) [explicit]

Constructs an empty DataSet with a given name.

Parameters:

name

: The DataSet's name.

Member Function Documentation

string getName ( ) const

Gets DataSet's name.

Returns:: The name of this DataSet.

void add	(	const string &	key,
		const value::Value &	value
	)

Adds a key-value pair to the DataSet.

Parameters:

	key	: The key;
	value	: The value.

KeyType::OutputType_ * find ( const KeyType & key ) const

Checks if key can be found.

This method checks if a key can be resolved. If resolution fails, then a null pointer is returned. Otherwise, this method processes the value associated to the key.

If the processing succeeds, then a pointer to the processed value is returned. If the processing fails an exception will be thrown.

Like getValue() (see below) this method gives access to the processed value corresponding to a specific key. The difference lies on how key resolution failures are reported. While find() returns a null pointer, getValue() throws an exception.

This method gives the ability to set default values for unresolved keys:

 // DataSet data;
 // ...
 //  const key::Single<bool> keyIsRegular("IsRegular");
 
 bool isRegular(true); // Set default value
 if (bool* ptr = data.find(keyIsRegular))
   isRegular = *ptr;

Parameters:

key

: The key to be checked.

Returns:: If the key can be found, this method returns a pointer to the corresponding processed value. Otherwise it returns a null pointer.

Set dependency graph.

Memoization.

Check input container type.

Process raw value.

Cache output.

KeyType::OutputType_ getValue ( const KeyType & key ) const

Gets and processes value associated to a key.

Parameters:

	KeyType	: (`template` parameter) Key's dynamic type;
	key	: Key associated to the value to be retrieved.

Returns:: Processed value which is associated to key.

value::Result process ( ) const

Processes a DataSet.

If key::Processor can be resolved for this DataSet, then the corresponding Processor (retrieved from ProcessorMngr) will be called to process this DataSet.

Returns:: Result of processing.

Exceptions:

RuntimeError

: If key::Processor cannot be resolved or if the processor named by key::Processor is not found.

value::PtrTraits< ObjectType >::Type_ build ( ) const

Builds the object defined by this DataSet provided its type.

The Processor named by key::Processor is retrieved and if it can build an object of type ObjectType, then the object is built and pointer to it is returned.

Parameters:

ObjectType : (template parameter) The type of object to be built.

Returns:: A pointer to the object.

bool mustUpdate ( ) const

Checks if there is need for reprocessing.

The process() method, pass this DataSet to the relevant Processor which will query for values through find() and getValue(). Memoization takes place and the DataSet caches these values and the processing result.

The Processor calls this method to compare the new and old (cached) set of values. If they agree this method returns false indicating that the result of previous processing is up to date and the Processor may return immediately.

Returns:: This method returns true if cached result of previous processing is out-of-date. Otherwise, it returns false.

Graph getGraph	(	const string &	key,
		bool	start = `true`
	)			const `[private]`

Gets the simplified dependency graph of a key.

If a key K₁ depends on K₂ which, in turn depends on K₃, and so on, up to K_n, then this method goes through all this dependency graph and returns a simplified version of it containing a pointer to K₁ and another to K_n. Additionally, when walking through the graph this method checks if any node has changed since the last time this graph was calculated.

Parameters:

	key	: The starting key (K₁ above);
	start	: This method is recursive and must be able to detected the root call (the called from outside this function) from the others (called by itself). This flag by default is set to `true` to indicate calling from outside.

const Processor& getProcessor ( ) const [private]

Gets the Processor expected to process this DataSet.

If key::Processor can be resolved for this DataSet, then the corresponding Processor (retrieved from ProcessorMngr) will be returned.

Returns:: The Processor expected to process this DataSet.

Exceptions:

RuntimeError

: If key::Processor cannot be resolved or if the processor named by key::Processor is not registered in ProcessorMngr.

value::Result process ( const Processor & processor ) const [private]

Processes this DataSet by a given Processor.

This method does not check the given Processor's name against the value associated to key::Processor.

Parameters:

processor

: The Processor that processes the DataSet.

Returns:: The result of the processing.

Friends And Related Function Documentation

::std::ostream& operator<<	(	::std::ostream &	os,
		const DataSet &	dataSet
	)			`[friend]`

ostream operator<<() for DataSet.

DataSet Class Reference

Classes

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation