linux-hardened/include/linux/textsearch_fsm.h
Thomas Graf 6408f79cce [LIB]: Naive finite state machine based textsearch
A finite state machine consists of n states (struct ts_fsm_token)
representing the pattern as a finite automation. The data is read
sequentially on a octet basis. Every state token specifies the number
of recurrences and the type of value accepted which can be either a
specific character or ctype based set of characters. The available
type of recurrences include 1, (0|1), [0 n], and [1 n].

The algorithm differs between strict/non-strict mode specyfing
whether the pattern has to start at the first octect. Strict mode
is enabled by default and can be disabled by inserting
TS_FSM_HEAD_IGNORE as the first token in the chain.

The runtime performance of the algorithm should be around O(n),
however while in strict mode the average runtime can be better.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-23 20:59:16 -07:00

48 lines
1.1 KiB
C

#ifndef __LINUX_TEXTSEARCH_FSM_H
#define __LINUX_TEXTSEARCH_FSM_H
#include <linux/types.h>
enum {
TS_FSM_SPECIFIC, /* specific character */
TS_FSM_WILDCARD, /* any character */
TS_FSM_DIGIT, /* isdigit() */
TS_FSM_XDIGIT, /* isxdigit() */
TS_FSM_PRINT, /* isprint() */
TS_FSM_ALPHA, /* isalpha() */
TS_FSM_ALNUM, /* isalnum() */
TS_FSM_ASCII, /* isascii() */
TS_FSM_CNTRL, /* iscntrl() */
TS_FSM_GRAPH, /* isgraph() */
TS_FSM_LOWER, /* islower() */
TS_FSM_UPPER, /* isupper() */
TS_FSM_PUNCT, /* ispunct() */
TS_FSM_SPACE, /* isspace() */
__TS_FSM_TYPE_MAX,
};
#define TS_FSM_TYPE_MAX (__TS_FSM_TYPE_MAX - 1)
enum {
TS_FSM_SINGLE, /* 1 occurrence */
TS_FSM_PERHAPS, /* 1 or 0 occurrence */
TS_FSM_ANY, /* 0..n occurrences */
TS_FSM_MULTI, /* 1..n occurrences */
TS_FSM_HEAD_IGNORE, /* 0..n ignored occurrences at head */
__TS_FSM_RECUR_MAX,
};
#define TS_FSM_RECUR_MAX (__TS_FSM_RECUR_MAX - 1)
/**
* struct ts_fsm_token - state machine token (state)
* @type: type of token
* @recur: number of recurrences
* @value: character value for TS_FSM_SPECIFIC
*/
struct ts_fsm_token
{
__u16 type;
__u8 recur;
__u8 value;
};
#endif