util-rohash.c File Reference

#include "suricata-common.h"
#include "util-hash.h"
#include "util-unittest.h"
#include "util-memcmp.h"
#include "util-hash-lookup3.h"
#include "util-rohash.h"
#include "util-debug.h"

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Data Structures
struct	ROHashTableItem_
struct	ROHashTableOffsets_

Typedefs
typedef struct ROHashTableItem_	ROHashTableItem
typedef struct ROHashTableOffsets_	ROHashTableOffsets

Functions
ROHashTable *	ROHashInit (uint8_t hash_bits, uint16_t item_size)
	initialize a new rohash More...
void	ROHashFree (ROHashTable *table)
uint32_t	ROHashMemorySize (ROHashTable *table)
void *	ROHashLookup (ROHashTable *table, void *data, uint16_t size)
int	ROHashInitQueueValue (ROHashTable *table, void *value, uint16_t size)
	Add a new value to the hash. More...
int	ROHashInitFinalize (ROHashTable *table)
	create final hash data structure More...

Detailed Description

Author

Victor Julien victo.nosp@m.r@in.nosp@m.linia.nosp@m.c.ne.nosp@m.t

Chained read only hash table implementation, meaning that after the initial fill no changes are allowed.

Loading takes 2 stages.

• stage1 maps data

• stage2 fills blob

  Todo:

  a bloomfilter in the ROHashTableOffsets could possibly prevent a lot of cache misses when validating a potential match

  Todo:

  maybe add a user ctx to be returned instead, something like a 4/8 byte ptr or simply a flag

Definition in file util-rohash.c.

Typedef Documentation

ROHashTableItem

typedef struct ROHashTableItem_ ROHashTableItem

item_size data beyond this header

ROHashTableOffsets

typedef struct ROHashTableOffsets_ ROHashTableOffsets

offset table

Function Documentation

ROHashFree()

void ROHashFree

(

ROHashTable *

table

)

Definition at line 91 of file util-rohash.c.

References ROHashTable_::data, and SCFree.

Referenced by DetectFileHashFree().

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ROHashInit()

ROHashTable* ROHashInit	(	uint8_t	hash_bits,
		uint16_t	item_size
	)

initialize a new rohash

Parameters

hash_bits	hash size as 2^hash_bits, so power of 2, max 31
item_size	size of the data to store

Return values

table

ptr or NULL on error

Definition at line 64 of file util-rohash.c.

References ROHashTable_::hash_bits, hashsize, ROHashTable_::item_size, ROHashTable_::items, SCCalloc, SCLogError, TAILQ_INIT, and unlikely.

ROHashInitFinalize()

int ROHashInitFinalize

(

ROHashTable *

table

)

create final hash data structure

Parameters

table

the hash table

Return values

0	error
1	ok

Note

after this call the nothing can be added to the hash anymore.

Definition at line 181 of file util-rohash.c.

References ROHashTableOffsets_::cnt, ROHashTable_::data, ROHashTable_::hash_bits, hashmask, hashsize, hashword(), ROHashTable_::item_size, ROHashTable_::items, ROHashTable_::locked, next, offset, ROHashTableOffsets_::offset, ROHashTableItem_::pos, SCCalloc, SCFree, SCLogError, TAILQ_FIRST, TAILQ_FOREACH, and TAILQ_REMOVE.

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ROHashInitQueueValue()

int ROHashInitQueueValue	(	ROHashTable *	table,
		void *	value,
		uint16_t	size
	)

Add a new value to the hash.

Note

can only be done when table isn't in a locked state yet

Parameters

table	the hash table
value	value to add
size	value size. MUST match table item_size

Return values

0	error
1	ok

Definition at line 151 of file util-rohash.c.

References ROHashTable_::item_size, ROHashTable_::locked, next, SCCalloc, SCLogError, and TAILQ_INSERT_TAIL.

Referenced by LoadHashTable().

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ROHashLookup()

void* ROHashLookup	(	ROHashTable *	table,
		void *	data,
		uint16_t	size
	)

Return values

NULL	not found
ptr	found

Definition at line 113 of file util-rohash.c.

References ROHashTableOffsets_::cnt, ROHashTable_::data, ROHashTable_::hash_bits, hashmask, hashword(), ROHashTable_::item_size, offset, ROHashTableOffsets_::offset, SCMemcmp, and SCReturnPtr.

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ROHashMemorySize()

uint32_t ROHashMemorySize

(

ROHashTable *

table

)

Definition at line 102 of file util-rohash.c.

References ROHashTable_::hash_bits, hashsize, ROHashTable_::item_size, and ROHashTable_::items.