buffer.h File Reference

Utility to assist with encode and decode operations. More...

Detailed Description

Utility to assist with encode and decode operations.

#include <stdlib.h>
#include <stdbool.h>
#include <stdio.h>
#include "util.h"

Go to the source code of this file.

Data Structures
struct	DasBuf
	Little buffer class to handle accumulating string data. More...

Functions
DasErrCode	DasBuf_initReadOnly (DasBuf *pThis, const char *sBuf, size_t uLen)
	Initialize a read-only buffer than points to an external byte array. More...
DasErrCode	DasBuf_paragraph (DasBuf *pThis, int nIndent1, int nIndent, int nWrap, const char *fmt,...)
	Write wrapped utf-8 text to the buffer. More...
int	DasBuf_writeFrom (DasBuf *pThis, FILE *pIn, size_t uLen)
	Add generic data to the buffer from a file. More...
int	DasBuf_writeFromSock (DasBuf *pThis, int nFd, size_t uLen)
	Add generic data to the buffer from a socket. More...
int	DasBuf_writeFromSSL (DasBuf *pThis, void *vpSsl, size_t uLen)
	Add generic data to the buffer from an OpenSSL object. More...
size_t	DasBuf_writeSpace (const DasBuf *pThis)
	Get the remaining write space in the buffer. More...
const char *	DasBuf_readRec (DasBuf *pThis, const char *sDelim, size_t uDelimLen, size_t *pLen)
	Return a pointer to the start of the current line and advance the read point to the start of the next line. More...
size_t	DasBuf_readOffset (const DasBuf *pThis)
	Get the offset of the read position. More...
DasErrCode	DasBuf_setReadOffset (DasBuf *pThis, size_t uPos)
	Set the offset of the read position. More...

Function Documentation

DasErrCode DasBuf_initReadOnly	(	DasBuf *	pThis,
		const char *	sBuf,
		size_t	uLen
	)

Initialize a read-only buffer than points to an external byte array.

This function re-sets the read point for the buffer.

Parameters

pThis	the buffer initialize
sBuf	an pre-allocated character buffer to receive new data
uLen	the length of the pre-allocated buffer

DasErrCode DasBuf_paragraph	(	DasBuf *	pThis,
		int	nIndent1,
		int	nIndent,
		int	nWrap,
		const char *	fmt,
			...
	)

Write wrapped utf-8 text to the buffer.

With the exception of explicit newline characters, this function uses white space only to separate words. Words are not split thus new-lines start at word boundaries.

The mentality of the function is to produce horizontal "paragraphs" of text that are space indented.

Parameters

pThis	the buffer to receive the text
nIndent1	the start column for the first line of text
nIndent	the start column for subsequent lines
nWrap	the wrap column, using 80 is recommended
fmt	A printf style format string, may contain utf-8 characters.

Returns

0 if the operation succeeded, a positive error code otherwise.

int DasBuf_writeFrom	(	DasBuf *	pThis,
		FILE *	pIn,
		size_t	uLen
	)

Add generic data to the buffer from a file.

Returns

Then number of bytes actually read, or a negative error code if there was a problem reading from the file.

int DasBuf_writeFromSock	(	DasBuf *	pThis,
		int	nFd,
		size_t	uLen
	)

Add generic data to the buffer from a socket.

Parameters

pThis	The buffer
nFd	The file descriptor associated with a readable socket
uLen	The amount of data to read

Returns

Then number of bytes actually read, or a negative error code if there was a problem reading from the socket.

int DasBuf_writeFromSSL	(	DasBuf *	pThis,
		void *	vpSsl,
		size_t	uLen
	)

Add generic data to the buffer from an OpenSSL object.

Parameters

pThis	The buffer
vpSsl	A void pointer to an SSL structure
uLen	The amount of data to read

Returns

Then number of bytes actually read, or a negative error code if there was a problem reading from the socket.

size_t DasBuf_writeSpace

(

const DasBuf *

pThis

)

Get the remaining write space in the buffer.

Parameters

pThis

The buffer

Returns

The number of bytes that may be still be written to the buffer.

const char* DasBuf_readRec	(	DasBuf *	pThis,
		const char *	sDelim,
		size_t	uDelimLen,
		size_t *	pLen
	)

Return a pointer to the start of the current line and advance the read point to the start of the next line.

The main use is for reading lines of character data, though any delimited byte stream can be read with this function.

Parameters

pThis	The DasBuf to read
sDelim	the line delimiter, typically this is just a single character string, but any string may be considered the line deliminter
uDelimLen	the length of the record deliminator in bytes
pLen	A pointer to a location to receive the line length, excluding the delimiter. The saved value will be zero for empty lines.

Returns

A pointer to the start of the current line, or NULL if no further lines are present in the buffer.

size_t DasBuf_readOffset

(

const DasBuf *

pThis

)

Get the offset of the read position.

Parameters

pThis

- The buffer to query

Returns

The difference between the read point and the base of the buffer

DasErrCode DasBuf_setReadOffset	(	DasBuf *	pThis,
		size_t	uPos
	)

Set the offset of the read position.

Parameters

pThis	- The buffer in question
uPos	- The new read offset from be beginning of the buffer

Returns

0 on success an positive error code if uPos makes no sense for the buffers current state