src/time_queue.c File Reference

#include <stdlib.h>
#include <stdio.h>
#include "time_queue.h"

Go to the source code of this file.

Functions
unsigned long	time_queue_hash (unsigned char *str)
	Internal: generates a djb2 hash.
time_queue *	time_queue_new (unsigned int size, unsigned int quota)
	Public: instantiates a new time queue, free it with time_queue_delete.
unsigned long	time_queue_time ()
	Internal: get the time.
void	time_queue_set (time_queue *queue, char *key)
	Public: set a time queue key to current time.
unsigned long *	time_queue_get (time_queue *queue, char *key)
	Public: get last stored time pointer for given key.
int	time_queue_overflows (time_queue *queue, char *key, unsigned int size)
	Internal: checks if the given key overflows the quota.
void	time_queue_delete (time_queue *queue)
	Public: deletes the time queue structure and allocated content.

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Detailed Description

A time queue is a datastructure which allows to store time for a finite number of keys. It allows to check if, for a given key, a limit per unit of time is reached or not.

Definition in file time_queue.c.

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Function Documentation

void time_queue_delete

(

time_queue *

queue

)

Public: deletes the time queue structure and allocated content.

Parameters:

queue

the queue to delete

Definition at line 149 of file time_queue.c.

unsigned long* time_queue_get	(	time_queue *	queue,
		char *	key
	)

Public: get last stored time pointer for given key.

Parameters:

queue	the time queue to modify
key	the key to get the value from

Examples

time_queue_get(queue, "/unset/key") => NULL time_queue_get(queue, "/existing/key") => pointer to: 1412074060579654

Returns:

a pointer to the time value registered, NULL if there is none

Definition at line 110 of file time_queue.c.

unsigned long time_queue_hash

(

unsigned char *

str

)

Internal: generates a djb2 hash.

Parameters:

str	the string to hash

Examples

time_queue_hash('hello world') => 13876786532495509697

Returns:

a hash for the string

Definition at line 21 of file time_queue.c.

time_queue* time_queue_new	(	unsigned int	size,
		unsigned int	quota
	)

Public: instantiates a new time queue, free it with time_queue_delete.

Parameters:

size	the maximum number of items saved in the queue
quota	the maximum size allowed per second per hash entry

Examples

time_queue_new(10, 42) => time_queue*

Returns:

a newly allocated pointer to a time queue of the specified size with the specified quota initialized to zero for values, and hashes

Definition at line 42 of file time_queue.c.

int time_queue_overflows	(	time_queue *	queue,
		char *	key,
		unsigned int	size
	)

Internal: checks if the given key overflows the quota.

Parameters:

queue	the time queue to get data from
key	the key to check
size	the size to compare with the quota

Examples

time_queue* queue = time_queue_new(10, 42); time_queue_set(queue, "/var/log/lol"); sleep(1); time_queue_overflows(queue, "/var/log/lol", 880); => 1

Returns:

0 if the key does not overflow the quota or no value exists for this key, 1 overwise

Definition at line 137 of file time_queue.c.

void time_queue_set	(	time_queue *	queue,
		char *	key
	)

Public: set a time queue key to current time.

Parameters:

queue	the time queue to modify
key	the key to set

Examples

time_queue_set(queue, "/var/log/blah.log")

Definition at line 75 of file time_queue.c.

unsigned long time_queue_time

(

)

Internal: get the time.

Returns:

current time in microseconds

Definition at line 60 of file time_queue.c.