Bloomfilter-based redundancy module

Files
file	redundancy_bloomfilter.c
	Implementation of a bloomfilter-based redundancy module.

Macros
#define	REDUNDANCE_SIZE   128
	How much RAM can we invest into detecting redundant bundles?
#define	REDUNDANCE_NUMBER   2
	How many bloomfilter shall we use in parallel?
#define	REDUNDANCE_LIMIT   100
	How many bundles should go into each of the filters?

Functions
uint32_t	bloomfilter_get_length ()
	Get the length of each bloomfilter. More...
char *	bloomfilter_get_start (uint8_t filter)
	Returns the pointer to the start of a bloom filter. More...
void	bloomfilter_set (uint32_t bit, uint8_t filter)
	Sets a bit in a given bloom filter. More...
uint8_t	bloomfilter_get (uint32_t bit, uint8_t filter)
	Checks if a certain bit is set in a bloom filter. More...
void	bloomfilter_clear (uint8_t filter)
	Clears the content of a bloom filter. More...
uint8_t	redundancy_bloomfilter_check (uint32_t bundle_number)
	checks if bundle was delivered before More...
uint8_t	redundancy_bloomfilter_set (uint32_t bundle_number)
	saves the bundle in a list of delivered bundles More...
void	redundancy_bloomfilter_init (void)
	Initialize the bloomfilters and various other state.

Variables
char	redundance_filters [REDUNDANCE_SIZE]
	Holds the bloomfilter(s)
uint8_t	redundance_counter = 0
	Counts the number of bundles in a bloom filter.
uint8_t	redundance_pointer = 0
	Points to the filter that is currently in use.

Detailed Description

Function Documentation

void bloomfilter_clear

(

uint8_t

filter

)

Clears the content of a bloom filter.

Parameters

filter

Number of the bloom filter

Definition at line 157 of file redundancy_bloomfilter.c.

References bloomfilter_get_length(), and bloomfilter_get_start().

Referenced by redundancy_bloomfilter_set().

uint8_t bloomfilter_get	(	uint32_t	bit,
		uint8_t	filter
	)

Checks if a certain bit is set in a bloom filter.

Parameters

bit	Offset of the bit to check
filter	Number of the filter to look into

Returns

1 if set, 0 otherwise

Definition at line 127 of file redundancy_bloomfilter.c.

References bloomfilter_get_start(), and NULL.

Referenced by redundancy_bloomfilter_check().

uint32_t bloomfilter_get_length

(

)

Get the length of each bloomfilter.

Returns

Length of each bloomfilter

Definition at line 76 of file redundancy_bloomfilter.c.

References REDUNDANCE_NUMBER, and REDUNDANCE_SIZE.

Referenced by bloomfilter_clear(), and bloomfilter_get_start().

char* bloomfilter_get_start

(

uint8_t

filter

)

Returns the pointer to the start of a bloom filter.

Parameters

filter

Number of the bloomfilter

Returns

Pointer to the filter

Definition at line 85 of file redundancy_bloomfilter.c.

References bloomfilter_get_length(), NULL, redundance_filters, and REDUNDANCE_NUMBER.

Referenced by bloomfilter_clear(), bloomfilter_get(), and bloomfilter_set().

void bloomfilter_set	(	uint32_t	bit,
		uint8_t	filter
	)

Sets a bit in a given bloom filter.

Parameters

bit	Offset of the bit to set
filter	Number of the bloomfilter

Definition at line 98 of file redundancy_bloomfilter.c.

References bloomfilter_get_start(), and NULL.

Referenced by redundancy_bloomfilter_set().

uint8_t redundancy_bloomfilter_check

(

uint32_t

bundle_number

)

checks if bundle was delivered before

Parameters

bundlemem

pointer to bundle

Returns

1 if bundle was delivered before, 0 otherwise

Definition at line 166 of file redundancy_bloomfilter.c.

References bloomfilter_get(), and REDUNDANCE_NUMBER.

uint8_t redundancy_bloomfilter_set

(

uint32_t

bundle_number

)

saves the bundle in a list of delivered bundles

Parameters

bundlemem

pointer to bundle

Returns

1 on successor 0 on error

Definition at line 192 of file redundancy_bloomfilter.c.

References bloomfilter_clear(), bloomfilter_set(), redundance_counter, REDUNDANCE_LIMIT, REDUNDANCE_NUMBER, and redundance_pointer.