ASSA::CharInBuffer Class Reference

CharInBuffer is a bucket for the character-based streams/messages. More...

#include <CharInBuffer.h>

Collaboration diagram for ASSA::CharInBuffer:

[legend]List of all members.

Public Types
enum	state_t { start, waiting, complete, error }
	States: start, waiting, complete, error. More...
Public Member Functions
	CharInBuffer (size_t size_, const string &delimiter_)
	Constructor.
	operator void * () const
	Test the state of an object.
const char *	c_str () const
	Get the constant character pointer to the buffer.
size_t	length () const
	Bytes in the buffer so far.
size_t	size () const
	Bytes in the buffer so far.
void	reset ()
	Discard all accumulated characters and be ready to receive a new message.
void	dump () const
	Write the state of an object to the log file.
state_t	state () const
	Report the current state of the object.
Private Member Functions
void	state (state_t new_state_)
	Go to the new state.
void	chop ()
	Remove the delimiter from the end of the buffer.
Static Private Member Functions
static const char *	state_name (state_t state_)
	Report the state name.
Private Attributes
state_t	m_state
	Internal state of an object.
std::string	m_buffer
	Buffer to store the bytes received.
size_t	m_max_size
	Maximum allowable size (delimiter included) before overflow occurs.
std::string	m_delimiter
	Delimiter. Multibyte delimiter is allowed.
Friends
ASSA::Socket &	operator>> (ASSA::Socket &, ASSA::CharInBuffer &)
	Read bytes from Socket stream until either record delimiter is detected, or EOF occured, or Socket stream is exhausted.

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Detailed Description

CharInBuffer is a bucket for the character-based streams/messages.

It helps in reading, parsing, and storing record-oriented character streams from Socket stream asynchronously. The record terminator can be multibyte. The terminator is detected and removed from the bucket. When terminator is detected, the block of characters collected in the bucket is ready to be processed further by the application according to its communication protocol. If either Socket read() error is encountered, or an overflow occurs (number of characters read exceeds the maximum limit), the object goes into the error state and won't accept further input, unless reset.

Definition at line 44 of file CharInBuffer.h.

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Member Enumeration Documentation

enum ASSA::CharInBuffer::state_t

States: start, waiting, complete, error. Enumerator: start  start state waiting  incomplete record is in the buffer complete  matched end-of-record - full record error  overflow or Socket I/O error Definition at line 85 of file CharInBuffer.h. { start, waiting, complete, error };

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Constructor & Destructor Documentation

CharInBuffer::CharInBuffer (  size_t  size_, const string &  delimiter_ )

Constructor. Parameters: size_  Maximum expected size before buffer overflow delimiter_  End-of-record character(s). Can be multi-byte. Definition at line 25 of file CharInBuffer.cpp. References ASSA::CHARINBUF, error, m_delimiter, m_max_size, state(), and trace_with_mask. : m_state (start), m_max_size (size_), m_delimiter (delimiter_) { trace_with_mask ("CharInBuffer::CharInBuffer", CHARINBUF); if (m_max_size == 0 || m_delimiter.length () == 0) { state (error); } state (waiting); }

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Member Function Documentation

const char* ASSA::CharInBuffer::c_str (   )  const [inline]

Get the constant character pointer to the buffer. Definition at line 66 of file CharInBuffer.h. References m_buffer. { return m_buffer.c_str (); }

void CharInBuffer::chop (   )  [inline, private]

Remove the delimiter from the end of the buffer. Definition at line 145 of file CharInBuffer.h. References m_buffer, and m_delimiter. { m_buffer.replace (m_buffer.find (m_delimiter), m_delimiter.length (), ""); }

void CharInBuffer::dump (   )  const

Write the state of an object to the log file. Definition at line 51 of file CharInBuffer.cpp. References ASSA::CHARINBUF, DL, ASSA::MemDump::dump_to_log(), m_buffer, m_delimiter, m_max_size, m_state, state_name(), and ASSA::TRACE. { DL((CHARINBUF,"== CharInBuffer state ==\n")); DL((CHARINBUF,"m_state = %s\n", state_name (m_state))); DL((CHARINBUF,"m_max_size = %d\n", m_max_size)); MemDump::dump_to_log (TRACE, "m_delimiter:\n", m_delimiter.c_str (), m_delimiter.length ()); MemDump::dump_to_log (TRACE, "m_buffer:\n", m_buffer.c_str (), m_buffer.length ()); DL((CHARINBUF,"========================\n")); }

size_t ASSA::CharInBuffer::length (   )  const [inline]

Bytes in the buffer so far. Definition at line 69 of file CharInBuffer.h. References m_buffer. { return m_buffer.length (); }

CharInBuffer::operator void * (   )  const [inline]

Test the state of an object. Returns: true if the object holds a complete message; false otherwise (eof, buffer overflow, or incomplete) Definition at line 128 of file CharInBuffer.h. References complete, and m_state. { return (m_state == complete ? (void *) (-1) // good state : (void *) 0); // bad state }

void CharInBuffer::reset (   )  [inline]

Discard all accumulated characters and be ready to receive a new message. Definition at line 137 of file CharInBuffer.h. References m_buffer, state(), and waiting. { m_buffer = ""; state (waiting); }

size_t ASSA::CharInBuffer::size (   )  const [inline]

Bytes in the buffer so far. Definition at line 72 of file CharInBuffer.h. References m_buffer. { return m_buffer.size (); }

void ASSA::CharInBuffer::state (  state_t  new_state_  )  [inline, private]

Go to the new state. Definition at line 100 of file CharInBuffer.h. References m_state. { m_state = new_state_; }

state_t ASSA::CharInBuffer::state (   )  const [inline]

Report the current state of the object. Definition at line 93 of file CharInBuffer.h. References m_state. Referenced by CharInBuffer(), ASSA::operator>>(), and reset(). { return m_state; }

const char * CharInBuffer::state_name (  state_t  state_  )  [static, private]

Report the state name. Definition at line 38 of file CharInBuffer.cpp. References error. Referenced by dump(), and ASSA::operator>>(). { static const char* vmsg[] = { "start", "waiting", "complete", "error", "unknown state" }; if (state_ < CharInBuffer::start || state_ > CharInBuffer::error) { return vmsg [sizeof (vmsg)-1]; } return vmsg [state_]; }

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Friends And Related Function Documentation

ASSA::Socket& operator>> (  ASSA::Socket &  s_, ASSA::CharInBuffer &  b_ )  [friend]

Read bytes from Socket stream until either record delimiter is detected, or EOF occured, or Socket stream is exhausted. If match, bite off delimiter and set the state to complete. If not, continue reading till either there is no more characters to read, or Socket error (Fail or EOF), or buffer overflow. If overflow occurs, set the state to 'error' and terminate. Definition at line 80 of file CharInBuffer.cpp. { trace_with_mask ("Socket >> CharInBuffer", CHARINBUF); register char c; if (b_.state () != CharInBuffer::waiting) { DL((CHARINBUF,"Wrong state %s\n", b_.state_name (b_.state ()))); return s_; } while (s_.read (&c, 1) == 1) { b_.m_buffer += c; if (b_.m_buffer.size() < b_.m_delimiter.size()) { // Bug # 1252926 continue; } if (b_.m_buffer.substr ( b_.m_buffer.size ()-b_.m_delimiter.size ()) == b_.m_delimiter) { b_.chop (); b_.m_state = CharInBuffer::complete; return s_; } if (b_.m_buffer.length () >= b_.m_max_size) { b_.m_state = CharInBuffer::error; break; } } if (!s_) { // EOF or error b_.state (CharInBuffer::error); } return s_; }

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Member Data Documentation

std::string ASSA::CharInBuffer::m_buffer [private]

Buffer to store the bytes received. Definition at line 110 of file CharInBuffer.h. Referenced by c_str(), chop(), dump(), length(), reset(), and size().

std::string ASSA::CharInBuffer::m_delimiter [private]

Delimiter. Multibyte delimiter is allowed. Definition at line 116 of file CharInBuffer.h. Referenced by CharInBuffer(), chop(), and dump().

size_t ASSA::CharInBuffer::m_max_size [private]

Maximum allowable size (delimiter included) before overflow occurs. Definition at line 113 of file CharInBuffer.h. Referenced by CharInBuffer(), and dump().

state_t ASSA::CharInBuffer::m_state [private]

Internal state of an object. Definition at line 107 of file CharInBuffer.h. Referenced by dump(), operator void *(), and state().

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

• /home/vlg/develop/libASSA/libassa/assa/CharInBuffer.h
• /home/vlg/develop/libASSA/libassa/assa/CharInBuffer.cpp

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