simplebuf.h File Reference

Simple [io] buffer declarations and operations. More...

#include <unistd.h>
#include "rnrconfig.h"

Go to the source code of this file.

Classes
struct	SimpleBuf_T

Macros
#define	SIMPLEBUF_ABS   0
	absolute
#define	SIMPLEBUF_REL   1
	relative

Functions
SimpleBuf_T *	SimpleBufNew ()
	Allocate a new simple buffer with no internal buffer allocation. More...
SimpleBuf_T *	SimpleBufNewWithBuf (size_t nBufSize)
	Allocate a new simple buffer with internal buffer of nBufSize. More...
void	SimpleBufDelete (SimpleBuf_T *pBuf)
	Delete a simple buffer along with the internal buffer. More...
void	SimpleBufSetBuf (SimpleBuf_T *pBuf, byte_t *pRWBuf, size_t nBufSize, size_t nLen)
	Set simple buffer's internal read/write buffer. More...
size_t	SimpleBufCopy (SimpleBuf_T *pTgt, SimpleBuf_T *pSrc)
	Copy contents of source simple buffer to the end of the target simple buffer. More...
static void	SimpleBufClear (SimpleBuf_T *pBuf)
	Clear contents of buffer. More...
static size_t	SimpleBufReadSeek (SimpleBuf_T *pBuf, size_t rpos, int how)
	Seek buffer read head to the new read position. More...
static size_t	SimpleBufWriteSeek (SimpleBuf_T *pBuf, size_t wpos, int how)
	Seek buffer write head to the new write position. More...
static size_t	SimpleBufHasSize (SimpleBuf_T *pBuf)
	Returns size of buffer. More...
static bool_t	SimpleBufIsEmpty (SimpleBuf_T *pBuf)
	Test if simple buffer is empty. More...
static bool_t	SimpleBufIsFull (SimpleBuf_T *pBuf)
	Test if simple buffer is full. More...
static size_t	SimpleBufHasLen (SimpleBuf_T *pBuf)
	Returns number of bytes currently in buffer. More...
static size_t	SimpleBufHasAvail (SimpleBuf_T *pBuf)
	Returns number of bytes available in buffer for writing. More...
static byte_t *	SimpleBufGetReadPtr (SimpleBuf_T *pBuf)
	Returns pointer to internal I/O buffer at the current read position. More...
static byte_t *	SimpleBufGetWritePtr (SimpleBuf_T *pBuf)
	Returns pointer to internal I/O buffer at the current write position. More...
static int	SimpleBufGetC (SimpleBuf_T *pBuf)
	Gets byte from buffer at current read position, advancing read position. More...
static int	SimpleBufPutC (SimpleBuf_T *pBuf, byte_t c)
	Puts byte into buffer at current write position, advancing write position. More...

Detailed Description

Simple [io] buffer declarations and operations.

The buffer is orgainized as a simple linear buffer with independent read and write positions. Ideal for multi-tasking.

* [----------buffer-----------------]
*     ^         ^                   ^
*     RPos      WPos                BufSize
* 

Package

RoadNarrows Robotics Common Library 1

Library

librnr

File

rnr/simplebuf.h

Author

Robin Knight (robin.nosp@m..kni.nosp@m.ght@r.nosp@m.oadn.nosp@m.arrow.nosp@m.s.co.nosp@m.m)

Copyright

© 2005-2018. RoadNarrows LLC..
http://www.roadnarrows.com
All Rights Reserved

License

MIT

EULA

See the README and EULA files for any copyright and licensing information.

—

Definition in file simplebuf.h.

Function Documentation

static void SimpleBufClear ( SimpleBuf_T *  pBuf )

inlinestatic

Clear contents of buffer.

Parameters

pBuf	Pointer to simple buffer.

Definition at line 89 of file simplebuf.h.

References SimpleBuf_T::m_nRPos, and SimpleBuf_T::m_nWPos.

Referenced by SocketBufClear().

{
  pBuf->m_nWPos = (size_t)0;
  pBuf->m_nRPos = (size_t)0;
}

size_t SimpleBufCopy	(	SimpleBuf_T *	pTgt,
		SimpleBuf_T *	pSrc
	)

Copy contents of source simple buffer to the end of the target simple buffer.

Parameters

pTgt	Pointer to target simple buffer.
pSrc	Pointer to source simple buffer.

Return Value:

Returns

Returns Number of bytes copied.

Definition at line 165 of file simplebuf.c.

References SimpleBuf_T::m_nBufSize, SimpleBuf_T::m_nRPos, SimpleBuf_T::m_nWPos, SimpleBuf_T::m_pRWBuf, and NULL.

{
  size_t  rpos, nBytes;

  if( (pTgt == NULL) || (pSrc == NULL) )
  {
    return (size_t)0;
  }

  for(rpos=pSrc->m_nRPos, nBytes=0;
      (rpos < pSrc->m_nWPos) && (pTgt->m_nWPos < pSrc->m_nBufSize);
      ++rpos, ++nBytes)
  {
    pTgt->m_pRWBuf[pTgt->m_nWPos++] = pSrc->m_pRWBuf[rpos];
  }

  return nBytes;
}

void SimpleBufDelete

(

SimpleBuf_T *

pBuf

)

Delete a simple buffer along with the internal buffer.

Actual deletion on occurs if buffer is owned by this simple buffer.

Parameters

pBuf	Pointer to simple buffer to be deleted.

Definition at line 111 of file simplebuf.c.

References SimpleBuf_T::m_bBufDel, SimpleBuf_T::m_pRWBuf, and NULL.

Referenced by SocketBufNewBuf(), and SocketDelete().

{
  if( pBuf == NULL )
  {
    return;
  }

  if( pBuf->m_bBufDel )
  {
    delete(pBuf->m_pRWBuf);
  }
  delete(pBuf);
}

static int SimpleBufGetC ( SimpleBuf_T *  pBuf )

inlinestatic

Gets byte from buffer at current read position, advancing read position.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns Read byte on success, -1 if buffer is empty.

Definition at line 227 of file simplebuf.h.

References SimpleBuf_T::m_nRPos, SimpleBuf_T::m_pRWBuf, and SimpleBufIsEmpty().

{
  if( !SimpleBufIsEmpty(pBuf) )
  {
    return (int)pBuf->m_pRWBuf[pBuf->m_nRPos++];
  }
  return -1;
}

static byte_t* SimpleBufGetReadPtr ( SimpleBuf_T *  pBuf )

inlinestatic

Returns pointer to internal I/O buffer at the current read position.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns byte* on success, NULL if buffer empty.

Definition at line 202 of file simplebuf.h.

References SimpleBuf_T::m_nRPos, SimpleBuf_T::m_pRWBuf, NULL, and SimpleBufIsEmpty().

Referenced by SocketWrite().

{
  return SimpleBufIsEmpty(pBuf)? NULL: pBuf->m_pRWBuf+pBuf->m_nRPos;
}

static byte_t* SimpleBufGetWritePtr ( SimpleBuf_T *  pBuf )

inlinestatic

Returns pointer to internal I/O buffer at the current write position.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns Returns byte* on success, NULL if buffer empty.

Definition at line 214 of file simplebuf.h.

References SimpleBuf_T::m_nWPos, SimpleBuf_T::m_pRWBuf, NULL, and SimpleBufIsFull().

Referenced by SocketRead().

{
  return SimpleBufIsFull(pBuf)? NULL: pBuf->m_pRWBuf+pBuf->m_nWPos;
}

static size_t SimpleBufHasAvail ( SimpleBuf_T *  pBuf )

inlinestatic

Returns number of bytes available in buffer for writing.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns ≥ 0.

Definition at line 190 of file simplebuf.h.

References SimpleBuf_T::m_nBufSize, and SimpleBuf_T::m_nWPos.

Referenced by SocketRead().

{
  return pBuf->m_nBufSize - pBuf->m_nWPos;
}

static size_t SimpleBufHasLen ( SimpleBuf_T *  pBuf )

inlinestatic

Returns number of bytes currently in buffer.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns ≥ 0.

Definition at line 178 of file simplebuf.h.

References SimpleBuf_T::m_nRPos, and SimpleBuf_T::m_nWPos.

Referenced by SocketBufGetLen(), and SocketWrite().

{
  return pBuf->m_nWPos - pBuf->m_nRPos;
}

static size_t SimpleBufHasSize ( SimpleBuf_T *  pBuf )

inlinestatic

Returns size of buffer.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns ≥ 0.

Definition at line 142 of file simplebuf.h.

References SimpleBuf_T::m_nBufSize.

Referenced by SocketBufGetSize().

{
  return pBuf->m_nBufSize;
}

static bool_t SimpleBufIsEmpty ( SimpleBuf_T *  pBuf )

inlinestatic

Test if simple buffer is empty.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns true or false.

Definition at line 154 of file simplebuf.h.

References SimpleBuf_T::m_nRPos, and SimpleBuf_T::m_nWPos.

Referenced by SimpleBufGetC(), and SimpleBufGetReadPtr().

{
  return pBuf->m_nRPos>=pBuf->m_nWPos? true: false;
}

static bool_t SimpleBufIsFull ( SimpleBuf_T *  pBuf )

inlinestatic

Test if simple buffer is full.

Parameters

pBuf	Pointer to simple buffer.

Returns

Returns true or false.

Definition at line 166 of file simplebuf.h.

References SimpleBuf_T::m_nBufSize, and SimpleBuf_T::m_nWPos.

Referenced by SimpleBufGetWritePtr(), and SimpleBufPutC().

{
  return pBuf->m_nWPos>=pBuf->m_nBufSize? true: false;
}

SimpleBuf_T* SimpleBufNew

(

)

Allocate a new simple buffer with no internal buffer allocation.

Returns

Returns SimpleBuf_T* to newly allocated simple buffer.

Definition at line 70 of file simplebuf.c.

References SimpleBuf_T::m_bBufDel, SimpleBuf_T::m_nBufSize, SimpleBuf_T::m_nRPos, SimpleBuf_T::m_nWPos, SimpleBuf_T::m_pRWBuf, NEW, and NULL.

Referenced by SocketNew().

{
  SimpleBuf_T *pBuf = NEW(SimpleBuf_T);

  pBuf->m_pRWBuf    = NULL;
  pBuf->m_nBufSize  = (size_t)0;
  pBuf->m_nRPos     = (size_t)0;
  pBuf->m_nWPos     = (size_t)0;
  pBuf->m_bBufDel   = false;

  return pBuf;
}

SimpleBuf_T* SimpleBufNewWithBuf

(

size_t

nBufSize

)

Allocate a new simple buffer with internal buffer of nBufSize.

Parameters

nBufSize

Size in bytes of internal buffer to allocate with simple buffer.

Returns

Returns SimpleBuf_T* to newly allocated simple buffer.

Definition at line 91 of file simplebuf.c.

References SimpleBuf_T::m_bBufDel, SimpleBuf_T::m_nBufSize, SimpleBuf_T::m_nRPos, SimpleBuf_T::m_nWPos, SimpleBuf_T::m_pRWBuf, and NEW.

Referenced by SocketBufNewBuf().

{
  SimpleBuf_T *pBuf = NEW(SimpleBuf_T);

  pBuf->m_pRWBuf    = (byte_t *)new(nBufSize);
  pBuf->m_nBufSize  = nBufSize;
  pBuf->m_nRPos     = (size_t)0;
  pBuf->m_nWPos     = (size_t)0;
  pBuf->m_bBufDel   = true;

  return pBuf;
}

static int SimpleBufPutC ( SimpleBuf_T *  pBuf, byte_t  c  )

inlinestatic

Puts byte into buffer at current write position, advancing write position.

Parameters

pBuf	Pointer to simple buffer.
c	Byte to put.

Returns

Returns Wrote byte on success, -1 if buffer is full.

Definition at line 245 of file simplebuf.h.

References C_DECLS_END, SimpleBuf_T::m_nWPos, SimpleBuf_T::m_pRWBuf, and SimpleBufIsFull().

{
  if( !SimpleBufIsFull(pBuf) )
  {
    pBuf->m_pRWBuf[pBuf->m_nWPos++] = c;
    return (int)c;
  }
  return -1;
}

static size_t SimpleBufReadSeek ( SimpleBuf_T *  pBuf, size_t  rpos, int  how  )

inlinestatic

Seek buffer read head to the new read position.

Parameters

pBuf	Pointer to simple buffer.
rpos	New read position.
how	Seek to absolute position (default) or relative to current position.

Returns

Returns new read position.

Definition at line 105 of file simplebuf.h.

References SimpleBuf_T::m_nRPos, SimpleBuf_T::m_nWPos, and SIMPLEBUF_REL.

Referenced by SocketWrite().

{
  if( how == SIMPLEBUF_REL )
  {
    rpos += pBuf->m_nRPos;
  }
  pBuf->m_nRPos = rpos<=pBuf->m_nWPos? rpos: pBuf->m_nWPos;
  return pBuf->m_nRPos;
}

void SimpleBufSetBuf	(	SimpleBuf_T *	pBuf,
		byte_t *	pRWBuf,
		size_t	nBufSize,
		size_t	nLen
	)

Set simple buffer's internal read/write buffer.

Parameters

pBuf	Pointer to simple buffer.
pRWBuf	Pointer to buffer to be set as the internal read/write buffer.
nBufSize	Size in bytes of pRWBuf.
nLen	Current length (bytes) of data in pRWBuf.

Definition at line 134 of file simplebuf.c.

References SimpleBuf_T::m_bBufDel, SimpleBuf_T::m_nBufSize, SimpleBuf_T::m_nRPos, SimpleBuf_T::m_nWPos, SimpleBuf_T::m_pRWBuf, and NULL.

Referenced by SocketBufSetBuf().

{
  if( pBuf == NULL )
  {
    return;
  }

  if( pBuf->m_bBufDel )
  {
    delete(pBuf->m_pRWBuf);
  }
 
  pBuf->m_pRWBuf    = pRWBuf;
  pBuf->m_nBufSize  = nBufSize;
  pBuf->m_nRPos     = (size_t)0;
  pBuf->m_nWPos     = nLen<=nBufSize? nLen: nBufSize;
  pBuf->m_bBufDel   = false;
}

static size_t SimpleBufWriteSeek ( SimpleBuf_T *  pBuf, size_t  wpos, int  how  )

inlinestatic

Seek buffer write head to the new write position.

Parameters

pBuf	Pointer to simple buffer.
wpos	New write position.
how	Seek to absolute position (default) or relative to current position.

Returns

Returns new write position.

Definition at line 125 of file simplebuf.h.

References SimpleBuf_T::m_nBufSize, SimpleBuf_T::m_nWPos, and SIMPLEBUF_REL.

Referenced by SocketRead().

{
  if( how == SIMPLEBUF_REL )
  {
    wpos += pBuf->m_nWPos;
  }
  pBuf->m_nWPos = wpos<=pBuf->m_nBufSize? wpos: pBuf->m_nBufSize;
  return pBuf->m_nWPos;
}