Context Class Reference
[Back-end Utility Components]

#include <pantheios/util/backends/context.hpp>

List of all members.

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Detailed Description

Framework class for assisting in the writing of Back-ends.

To use pantheios::util::backends::Context, you derive from it, and override the rawLogEntry() method, as in the implementation of be.speech:

struct be_speech_context
    : public pantheios::util::backends::Context
{
public: // Member Types
  typedef pantheios::util::backends::Context  parent_class_type;
  typedef be_speech_context                   class_type;
  typedef std::string                         string_type;
  typedef stlsoft::ref_ptr<ISpVoice>          voice_type;

public: // Construction
  be_speech_context(pan_char_t const* processIdentity, int id, pantheios::uint32_t flags, voice_type voice);
  ~be_speech_context() throw();

private: // Overrides
  virtual int rawLogEntry(int severity, const pan_slice_t (&ar)[rawLogArrayDimension], size_t cchTotal);

  . . .
};

An instance of the derived class is created in the back-end initialisation function, and destroyed in the uninitialisation function, each of which are called a maximum of one time per program execution.

Finally, in the implementation of the back-end's log entry function, the logEntry() method is called, as in:

static int pantheios_be_speech_logEntry(  void*             // feToken
                                        , void*             beToken
                                        , int               severity
                                        , pan_char_t const* entry
                                        , size_t            cchEntry)
{
  PANTHEIOS_CONTRACT_ENFORCE_PRECONDITION_PARAMS_API(NULL != beToken, "back-end token may not be null");

  be_speech_context* ctxt = static_cast<be_speech_context*>(beToken);

  return ctxt->logEntry(severity, entry, cchEntry);
}

Member Variables
pan_char_t *const	m_processIdentity
int const	m_id
pan_uint32_t const	m_flags
int const	m_severityMask
Public Types
Member Types
typedef Context	class_type
Public Member Functions
Operations
int	logEntry (int severity, pan_char_t const *entry, size_t cchEntry)
	Note: This method does not mutate any member data.
Accessors
pan_char_t const *	getProcessIdentity () const
	The process identity.
int	getBackEndId () const
Protected Types
Member Constants
enum	{ rawLogArrayDimension = 10 }
Protected Member Functions
Construction
	Context (pan_char_t const *processIdentity, int id, pan_uint32_t flags, int severityMask)
	Constructs an instance.
virtual	~Context () throw ()
Static Protected Member Functions
Utilities
static size_t	concatenateSlices (pan_char_t *dest, size_t cchDest, size_t numSlices, pan_slice_t const *slices)
	Concatenates the slices into the given destination.

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Constructor & Destructor Documentation

Context	(	pan_char_t const *	processIdentity,
		int	id,
		pan_uint32_t	flags,
		int	severityMask
	)			[protected]

Constructs an instance.

Parameters:

	processIdentity	The process identity. May not be NULL or empty
	id	The back-end identifier
	flags	Flags that control the elements presented in the log statements
	severityMask	Mask that prescribes the valid range of the severity for the derived class. Must be either 0x07 or 0x0f

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Member Function Documentation

int logEntry	(	int	severity,
		pan_char_t const *	entry,
		size_t	cchEntry
	)

Note:

This method does not mutate any member data.

It is not marked const solely because it invokes rawLogEntry(), which may need to mutate member data of the derived class (though this will not be the dominant form).

Note:

Because the method does not, in and of itself, mutate data, backends using the class may only need to lock if the underlying transmission medium requires it, and this may only need to be inside the call to rawLogEntry(), on a back-end-specific basis.

static size_t concatenateSlices	(	pan_char_t *	dest,
		size_t	cchDest,
		size_t	numSlices,
		pan_slice_t const *	slices
	)			[static, protected]

Concatenates the slices into the given destination.

pan_char_t const* getProcessIdentity

(

)

const

The process identity.

Note:

In builds where exceptions are not enabled, or with compilers that do not throw std::bad_alloc on allocation failure, this will return NULL to indicate that construction has failed

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

• pantheios/util/backends/context.hpp

pantheios Library documentation © Matthew Wilson & Synesis Software, 2006-2011