diff options
| author | Thomas Graf <tgraf@suug.ch> | 2005-06-23 20:59:16 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2005-06-23 20:59:16 -0700 |
| commit | 6408f79cce401e1bfecf923e7156f84f96e021e3 (patch) | |
| tree | 203624ffacf60d364293adc47d2f59f6ba81dd35 /include | |
| parent | df3fb93ad9ec0b20c785c0ad82d42d159a1af272 (diff) | |
[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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/textsearch_fsm.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/include/linux/textsearch_fsm.h b/include/linux/textsearch_fsm.h new file mode 100644 index 00000000000..fdfa078c66e --- /dev/null +++ b/include/linux/textsearch_fsm.h @@ -0,0 +1,48 @@ +#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 |