pfodCircularLineBuffer Class Reference

pfodCircularLineBuffer - Line-aware circular buffer for CSV data streaming More...

#include <pfodCircularLineBuffer.h>

Inherits Stream.

Public Member Functions
	pfodCircularLineBuffer (size_t bufferSize=4096)
	Constructor - Initializes empty circular buffer with specified size. More...
	~pfodCircularLineBuffer ()
	Destructor - Cleans up buffer memory. More...
size_t	addLine (const char *line)
	Adds a complete line to the buffer (must include \r terminator). More...
size_t	addLine (const String &line)
	Adds a complete line to the buffer (must include \r terminator). More...
void	getRange (size_t fromLineCount, BufferRange &range)
	Gets buffer range starting from specified line number. More...
void	getAllRange (BufferRange &range)
	Gets buffer range for all available data. More...
void	setReadRange (const BufferRange &range)
	Sets the current read position to a specific buffer range. More...
void	resetForRead ()
	Resets read position to beginning of all available data. More...
size_t	getStartLineCount () const
	Gets the current start line number (oldest available line). More...
size_t	getEndLineCount () const
	Gets the current end line number (newest line + 1). More...
size_t	getLineCount () const
	Gets total number of lines currently in buffer. More...
size_t	getBufferSize () const
	Gets the configured buffer size. More...
size_t	getUsedBytes () const
	Gets number of bytes currently used in buffer. More...
size_t	getAvailableBytes () const
	Gets number of bytes available in buffer. More...
bool	isEmpty () const
	Checks if buffer is empty. More...
void	clear ()
	Clears all data from buffer and resets line counts. More...
void	debugBufferRange (Print *outPtr)
	Prints debug information about buffer state and positions. More...
virtual int	available () override
	Returns number of bytes available to read from current read range. More...
virtual int	peek () override
	Reads one byte from current read range without advancing position. More...
virtual int	read () override
	Reads one byte from current read range and advances position. More...
virtual size_t	write (uint8_t c) override
	Write single byte to buffer. More...
virtual size_t	write (const uint8_t *buffer, size_t size) override
	Write buffer. More...

Detailed Description

pfodCircularLineBuffer - Line-aware circular buffer for CSV data streaming

Maintains complete lines only, automatically adjusting start position when buffer wraps to ensure no partial lines. Tracks line counts for efficient retrieval by line number.

Implements Arduino Stream interface for reading data.

Definition at line 40 of file pfodCircularLineBuffer.h.

Constructor & Destructor Documentation

pfodCircularLineBuffer()

pfodCircularLineBuffer::pfodCircularLineBuffer

(

size_t

bufferSize = 4096

)

Constructor - Initializes empty circular buffer with specified size.

buffersize must be > line lenght, if buffersize is < line length no data will be available to read

Parameters

bufferSize

Size of buffer in bytes (default: 4096)

~pfodCircularLineBuffer()

pfodCircularLineBuffer::~pfodCircularLineBuffer

(

)

Destructor - Cleans up buffer memory.

Member Function Documentation

addLine() [1/2]

size_t pfodCircularLineBuffer::addLine

(

const char *

line

)

Adds a complete line to the buffer (must include \r
terminator).

Uses Print interface to write characters. If wrapping occurs and overwrites start position, adjusts start to next complete line.

Parameters

line	String containing complete line with \r terminator

Returns

Number of bytes written

addLine() [2/2]

size_t pfodCircularLineBuffer::addLine

(

const String &

line

)

Adds a complete line to the buffer (must include \r
terminator).

Uses Print interface to write characters. If wrapping occurs and overwrites start position, adjusts start to next complete line.

Parameters

line	String containing complete line with \r terminator

Returns

Number of bytes written

available()

virtual int pfodCircularLineBuffer::available ( )

overridevirtual

Returns number of bytes available to read from current read range.

Returns

Number of bytes available

clear()

void pfodCircularLineBuffer::clear

(

)

Clears all data from buffer and resets line counts.

debugBufferRange()

void pfodCircularLineBuffer::debugBufferRange

(

Print *

outPtr

)

Prints debug information about buffer state and positions.

Outputs buffer range, stream positions, line counts, and usage stats.

Parameters

outPtr

Pointer to Print object for output (e.g., &Serial). Returns silently if null.

getAllRange()

void pfodCircularLineBuffer::getAllRange

(

BufferRange &

range

)

Gets buffer range for all available data.

Parameters

range

Output parameter filled with start/end byte positions and line counts

getAvailableBytes()

size_t pfodCircularLineBuffer::getAvailableBytes ( ) const

inline

Gets number of bytes available in buffer.

Returns

Bytes available for new data

Definition at line 148 of file pfodCircularLineBuffer.h.

getBufferSize()

size_t pfodCircularLineBuffer::getBufferSize ( ) const

inline

Gets the configured buffer size.

Returns

Total buffer size in bytes

Definition at line 134 of file pfodCircularLineBuffer.h.

getEndLineCount()

size_t pfodCircularLineBuffer::getEndLineCount ( ) const

inline

Gets the current end line number (newest line + 1).

Returns

Line number after last line in buffer

Definition at line 120 of file pfodCircularLineBuffer.h.

getLineCount()

size_t pfodCircularLineBuffer::getLineCount ( ) const

inline

Gets total number of lines currently in buffer.

Returns

Number of complete lines stored

Definition at line 127 of file pfodCircularLineBuffer.h.

getRange()

void pfodCircularLineBuffer::getRange	(	size_t	fromLineCount,
		BufferRange &	range
	)

Gets buffer range starting from specified line number.

Returns data from that line until end of buffer. If requested line is older than available, returns from earliest line.

Parameters

fromLineCount	Line number to start from
range	Output parameter filled with start/end byte positions and line counts

getStartLineCount()

size_t pfodCircularLineBuffer::getStartLineCount ( ) const

inline

Gets the current start line number (oldest available line).

Returns

Line number of first available line in buffer

Definition at line 113 of file pfodCircularLineBuffer.h.

getUsedBytes()

size_t pfodCircularLineBuffer::getUsedBytes

(

)

const

Gets number of bytes currently used in buffer.

Returns

Bytes of data stored

isEmpty()

bool pfodCircularLineBuffer::isEmpty ( ) const

inline

Checks if buffer is empty.

Returns

true if buffer contains no data

Definition at line 155 of file pfodCircularLineBuffer.h.

peek()

virtual int pfodCircularLineBuffer::peek ( )

overridevirtual

Reads one byte from current read range without advancing position.

Returns

Byte value (0-255) or -1 if no data available

read()

virtual int pfodCircularLineBuffer::read ( )

overridevirtual

Reads one byte from current read range and advances position.

Returns

Byte value (0-255) or -1 if no data available

resetForRead()

void pfodCircularLineBuffer::resetForRead

(

)

Resets read position to beginning of all available data.

Convenience method that calls getAllRange() and setReadRange(). Subsequent Stream read operations will read from start of buffer.

setReadRange()

void pfodCircularLineBuffer::setReadRange

(

const BufferRange &

range

)

Sets the current read position to a specific buffer range.

Subsequent Stream read operations will read from this range.

Parameters

range

BufferRange specifying what to read

write() [1/2]

virtual size_t pfodCircularLineBuffer::write ( const uint8_t *  buffer, size_t  size  )

overridevirtual

Write buffer.

Calls write(uint8_t) for each byte.

Parameters

buffer	Data to write
size	Number of bytes

Returns

Number of bytes written

write() [2/2]

virtual size_t pfodCircularLineBuffer::write ( uint8_t  c )

overridevirtual

Write single byte to buffer.

Used by addLine() via Print interface. Automatically wraps and adjusts start position when \r
detected.

Parameters

c	Byte to write

Returns

1 if written, 0 if failed