ucommon
Public Types | Public Member Functions | Protected Member Functions | Protected Attributes
ucommon::BufferProtocol Class Reference

Common buffer protocol class. More...

#include <protocols.h>

Inheritance diagram for ucommon::BufferProtocol:
Inheritance graph
[legend]
Collaboration diagram for ucommon::BufferProtocol:
Collaboration graph
[legend]

Public Types

enum  mode_t { RDONLY, WRONLY, RDWR }

Public Member Functions

const char * endl (void)
bool eof (void)
 Check if at end of input.
int err (void)
bool flush (void)
 Flush buffered memory to physical I/O.
size_t get (void *address, size_t count)
 Get memory from the buffer.
bool is_input (void)
 See if input active.
bool is_open (void)
 See if buffer open.
bool is_output (void)
 See if output active.
bool is_pending (void)
 See if pending input.
 operator bool ()
 See if buffer open.
bool operator! ()
 See if buffer closed.
size_t printf (const char *format,...)
 Print formatted string to the buffer.
void purge (void)
 Purge any pending input or output buffer data.
size_t put (const void *address, size_t count)
 Put memory into the buffer.
template<typename T >
size_t read (T &data)
template<typename T >
size_t read (T *data, unsigned count)
void reset (void)
 Reset input buffer state.
void seteof (void)
 Set eof flag.
template<typename T >
size_t write (const T &data)
template<typename T >
size_t write (const T *data, unsigned count)

Protected Member Functions

virtual bool _blocking (void)
 Return true if blocking.
virtual void _clear (void)=0
 Method to clear low level i/o error.
virtual int _err (void) const =0
 Method to get low level i/o error.
virtual bool _flush (void)
 Flush buffer to physical i/o.
virtual int _getch (void)
 Get the next character.
virtual bool _pending (void)
 Check if data is pending.
virtual size_t _pull (char *address, size_t size)=0
 Method to pull buffer from physical i/o (read).
virtual size_t _push (const char *address, size_t size)=0
 Method to push buffer into physical i/o (write).
virtual int _putch (int ch)
 Put the next character.
void allocate (size_t size, mode_t access=RDWR)
 Allocate I/O buffer(s) of specified size.
 BufferProtocol ()
 Construct an empty (unallocated) buffer.
 BufferProtocol (size_t size, mode_t access=RDWR)
 Construct a buffer of pre-allocated size and access type.
virtual void fault (void) const
 Allocation error handler.
char * gather (size_t size)
 Gather returns a pointer to contiguous input of specified size.
size_t input_pending (void)
 Get current input position.
size_t output_waiting (void)
 Get current output position.
void release (void)
 Release (free) buffer memory.
char * request (size_t size)
 Request workspace in output buffer.
virtual ~BufferProtocol ()
 Destroy object by releasing buffer memory.

Protected Attributes

const char * format

Detailed Description

Common buffer protocol class.

This is used to create objects which will stream character data as needed. This class can support bidirectional streaming as may be needed for serial devices, sockets, and pipes. The buffering mechanisms are hidden from derived classes, and two virtuals are used to communicate with the physical transport.

Author:
David Sugar <dyfet@gnutelephony.org>

Definition at line 291 of file protocols.h.


Constructor & Destructor Documentation

ucommon::BufferProtocol::BufferProtocol ( size_t  size,
mode_t  access = RDWR 
) [protected]

Construct a buffer of pre-allocated size and access type.

Parameters:
sizeof buffer to allocate.
accessmode of buffer.

Member Function Documentation

virtual int ucommon::BufferProtocol::_err ( void  ) const [protected, pure virtual]

Method to get low level i/o error.

Returns:
error from low level i/o methods.

Implemented in ucommon::TCPBuffer.

virtual int ucommon::BufferProtocol::_getch ( void  ) [protected, virtual]

Get the next character.

Returns:
next character or EOF.

Implements ucommon::CharacterProtocol.

virtual size_t ucommon::BufferProtocol::_pull ( char *  address,
size_t  size 
) [protected, pure virtual]

Method to pull buffer from physical i/o (read).

The address is passed to this virtual since it is hidden as private.

Parameters:
addressof buffer to pull data into.
sizeof buffer area being pulled..
Returns:
number of read written, 0 on error or end of data.

Implemented in ucommon::SSLBuffer, and ucommon::TCPBuffer.

virtual size_t ucommon::BufferProtocol::_push ( const char *  address,
size_t  size 
) [protected, pure virtual]

Method to push buffer into physical i/o (write).

The address is passed to this virtual since it is hidden as private.

Parameters:
addressof data to push.
sizeof data to push.
Returns:
number of bytes written, 0 on error.

Implemented in ucommon::SSLBuffer, and ucommon::TCPBuffer.

virtual int ucommon::BufferProtocol::_putch ( int  code) [protected, virtual]

Put the next character.

Parameters:
codeto put.
Returns:
code or EOF if cannot put.

Implements ucommon::CharacterProtocol.

void ucommon::BufferProtocol::allocate ( size_t  size,
mode_t  access = RDWR 
) [protected]

Allocate I/O buffer(s) of specified size.

If a buffer is currently allocated, it is released.

Parameters:
sizeof buffer to allocate.
accessmode of buffer.

Check if at end of input.

Returns:
true if end of data, false if input still buffered.
bool ucommon::BufferProtocol::flush ( void  ) [inline]

Flush buffered memory to physical I/O.

Returns:
true on success, false if not active or fails.

Definition at line 453 of file protocols.h.

char* ucommon::BufferProtocol::gather ( size_t  size) [protected]

Gather returns a pointer to contiguous input of specified size.

This may require moving the input data in memory.

Parameters:
sizeof gather space.
Returns:
data pointer to gathered data or NULL if not available.
size_t ucommon::BufferProtocol::get ( void *  address,
size_t  count 
)

Get memory from the buffer.

Parameters:
addressof characters save from buffer.
countof characters to get from buffer.
Returns:
number of characters actually copied.
size_t ucommon::BufferProtocol::input_pending ( void  ) [inline, protected]

Get current input position.

Sometimes used to help compute and report a "tell" offset.

Returns:
offset of input buffer.

Definition at line 410 of file protocols.h.

bool ucommon::BufferProtocol::is_input ( void  ) [inline]

See if input active.

Returns:
true if input active.

Definition at line 497 of file protocols.h.

bool ucommon::BufferProtocol::is_open ( void  ) [inline]

See if buffer open.

Returns:
true if buffer active.

Definition at line 490 of file protocols.h.

bool ucommon::BufferProtocol::is_output ( void  ) [inline]

See if output active.

Returns:
true if output active.

Definition at line 504 of file protocols.h.

bool ucommon::BufferProtocol::is_pending ( void  ) [inline]

See if pending input.

Returns:
true if input pending.

Definition at line 511 of file protocols.h.

ucommon::BufferProtocol::operator bool ( ) [inline]

See if buffer open.

Returns:
true if buffer active.

Definition at line 476 of file protocols.h.

See if buffer closed.

Returns:
true if buffer inactive.

Definition at line 483 of file protocols.h.

size_t ucommon::BufferProtocol::output_waiting ( void  ) [inline, protected]

Get current output position.

Sometimes used to help compute a "trunc" operation.

Definition at line 417 of file protocols.h.

size_t ucommon::BufferProtocol::printf ( const char *  format,
  ... 
)

Print formatted string to the buffer.

The maximum output size is the buffer size, and the operation flushes the buffer.

Parameters:
formatstring.
Returns:
number of bytes written.
size_t ucommon::BufferProtocol::put ( const void *  address,
size_t  count 
)

Put memory into the buffer.

If count is 0 then put as NULL terminated string.

Parameters:
addressof characters to put into buffer.
countof characters to put into buffer.
Returns:
number of characters actually written.
char* ucommon::BufferProtocol::request ( size_t  size) [protected]

Request workspace in output buffer.

This returns a pointer to memory from the output buffer and advances the output position. This is sometimes used for a form of zero copy write.

Parameters:
sizeof request area.
Returns:
data pointer or NULL if not available.

Reset input buffer state.

Drops any pending input.


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