prom/include/prom_string_builder.h File Reference

A StringBuilder: uses an internal buffer to append strings and characters as needed and keeps track of the constructed string, grows the buffer by factor 2 automagically. More...

#include <stddef.h>

Include dependency graph for prom_string_builder.h:

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Typedefs
typedef struct psb	psb_t
Functions
psb_t *	psb_new (void)
	Setup a new string builder.
int	psb_destroy (psb_t *self)
	Destroys the given string builder.
int	psb_add_str (psb_t *self, const char *str)
	Append the given string to the buffered string of the given string builder.
int	psb_add_char (psb_t *self, char c)
	Append the given character to the buffered string of the given string builder.
int	psb_clear (psb_t *self)
	Free the allocated string buffer area of the given string builder, allocate a new one with a default initial size and set its length to 0.
int	psb_truncate (psb_t *self, size_t len)
	Set the length of the buffered string of the given string builder to the given length and append '\0'.
size_t	psb_len (psb_t *self)
	Get the length of the buffered string of the given string builder.
char *	psb_dump (psb_t *self)
	Get a copy of the buffered string of the given string builder.
char *	psb_str (psb_t *self)
	Get a reference to the buffered string.

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Detailed Description

A StringBuilder: uses an internal buffer to append strings and characters as needed and keeps track of the constructed string, grows the buffer by factor 2 automagically.

Note:

All psb_t parameter in the related functions are expected to be != NULL, otherwise be prepared for core dumps.

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Function Documentation

int psb_add_char	(	psb_t *	self,
		char	c
	)

Append the given character to the buffered string of the given string builder.

Parameters:

self	Where to append the character.
c	Character to append.

Returns:

0 on success, a number > 0 otherwise.

int psb_add_str	(	psb_t *	self,
		const char *	str
	)

Append the given string to the buffered string of the given string builder.

Parameters:

self	Where to append the string.
str	String to append.

Returns:

0 on success, a number > 0 otherwise.

int psb_clear

(

psb_t *

self

)

Free the allocated string buffer area of the given string builder, allocate a new one with a default initial size and set its length to 0.

Parameters:

self	String builder to free.

Returns:

0 on success, a number > 0 otherwise.

int psb_destroy

(

psb_t *

self

)

Destroys the given string builder.

Parameters:

self	String builder to destroy.

Returns:

0 .

char* psb_dump

(

psb_t *

self

)

Get a copy of the buffered string of the given string builder.

Parameters:

self	String builder to ask.

Returns:

Metric as string in Prometheus exposition format.

Note:

The returned string must be freed when no longer needed.

size_t psb_len

(

psb_t *

self

)

Get the length of the buffered string of the given string builder.

Parameters:

self	String builder to query.

Returns:

The length of the buffered string.

psb_t* psb_new

(

void

)

Setup a new string builder.

Returns:

A new string builder or NULL on error.

char* psb_str

(

psb_t *

self

)

Get a reference to the buffered string.

One should **NOT** modify the string, treat it as a read-only and never ever free() it, otherwise be prepared for buffer overflows and core dumps. It has been made public solely to avoid the strdup() overhead of psb_dump().

Returns:

a string, or NULL if not initialized yet.

int psb_truncate	(	psb_t *	self,
		size_t	len
	)

Set the length of the buffered string of the given string builder to the given length and append '\0'.

Parameters:

self	String builder to truncate.
len	The new length of the buffered string. If it is bigger than its current length, this function is a no-op.

Returns:

0 on success, a number > 0 otherwise.