printbuf.h File Reference

Internal string buffer handing. Unless you're writing a json_object_to_json_string_fn implementation for use with json_object_set_serializer() direct use of this is not recommended. More...

Data Structures
struct	printbuf

Macros
#define	printbuf_memappend_fast(p, bufptr, bufsize)
#define	printbuf_length(p)   ((p)->bpos)
#define	_printbuf_check_literal(mystr)   ("" mystr)
#define	printbuf_strappend(pb, str)   printbuf_memappend ((pb), _printbuf_check_literal(str), sizeof(str) - 1)

Typedefs
typedef struct printbuf	printbuf

Functions
struct printbuf *	printbuf_new (void)
int	printbuf_memappend (struct printbuf *p, const char *buf, int size)
int	printbuf_memset (struct printbuf *pb, int offset, int charvalue, int len)
int	sprintbuf (struct printbuf *p, const char *msg,...)
void	printbuf_reset (struct printbuf *p)
void	printbuf_free (struct printbuf *p)

Detailed Description

Internal string buffer handing. Unless you're writing a json_object_to_json_string_fn implementation for use with json_object_set_serializer() direct use of this is not recommended.

Macro Definition Documentation

#define _printbuf_check_literal

(

mystr

)

("" mystr)

Results in a compile error if the argument is not a string literal.

#define printbuf_length

(

p

)

((p)->bpos)

#define printbuf_memappend_fast	(		p,
			bufptr,
			bufsize
	)

Value:

do {                                                         \
  if ((p->size - p->bpos) > bufsize) {                       \
    memcpy(p->buf + p->bpos, (bufptr), bufsize);             \
    p->bpos += bufsize;                                      \
    p->buf[p->bpos]= '\0';                                   \
  } else {  printbuf_memappend(p, (bufptr), bufsize); }      \
} while (0)

#define printbuf_strappend	(		pb,
			str
	)		printbuf_memappend ((pb), _printbuf_check_literal(str), sizeof(str) - 1)

This is an optimization wrapper around printbuf_memappend() that is useful for appending string literals. Since the size of string constants is known at compile time, using this macro can avoid a costly strlen() call. This is especially helpful when a constant string must be appended many times. If you got here because of a compilation error caused by passing something other than a string literal, use printbuf_memappend_fast() in conjunction with strlen().

See also: printbuf_memappend_fast() printbuf_memappend() sprintbuf()

Typedef Documentation

typedef struct printbuf printbuf

Function Documentation

void printbuf_free

(

struct printbuf *

p

)

int printbuf_memappend	(	struct printbuf *	p,
		const char *	buf,
		int	size
	)

int printbuf_memset	(	struct printbuf *	pb,
		int	offset,
		int	charvalue,
		int	len
	)

Set len bytes of the buffer to charvalue, starting at offset offset. Similar to calling memset(x, charvalue, len);

The memory allocated for the buffer is extended as necessary.

If offset is -1, this starts at the end of the current data in the buffer.

struct printbuf* printbuf_new

(

void

)

void printbuf_reset

(

struct printbuf *

p

)

int sprintbuf	(	struct printbuf *	p,
		const char *	msg,
			...
	)

Formatted print to printbuf.

This function is the most expensive of the available functions for appending string data to a printbuf and should be used only where convenience is more important than speed. Avoid using this function in high performance code or tight loops; in these scenarios, consider using snprintf() with a static buffer in conjunction with one of the printbuf_*append() functions.

See also: printbuf_memappend_fast() printbuf_memappend() printbuf_strappend()