matching.h File Reference

---

Detailed Description

Search table searching routines.

Basic explanation of how search table works:

A search_table is a global object. Only one of these is expected to exist. It consists of a number of "bins", each bin containing all entries which have a certain sequence of two characters in a row, plus some metadata.

Each bin is a simple array, without repetitions, of items. Each item consists of a string to which a certain mapping of characters onto characters has been applied, plus a void * representing the actual data mapped to. (I used void * to make this code reasonably generic, so that in any project I or someone else wants to use code like this for, they can just use it.) The same mapping is also applied to each search before running it. This maps uppercase and lowercase letters to match one another, maps all whitespace and punctuation to a simple space, etc. This mechanism is very flexible and could easily be adapted to match accented characters, etc.

The actual search builds a regular expression to do the matching. This might have a tiny bit higher overhead than a custom implementation of string matching, but it also allows a great deal of flexibility and ease of experimentation with different search techniques, both to increase efficiency and to give the best possible results. Hopefully the code is reasonably self-explanatory, but if you find it confusing, email the gtk-gnutella-devel mailing list and I'll try to respond...

Author:

Raphael Manfredi

Date:

2001-2003

Author:

KBH

Date:

2001-10-03

Go to the source code of this file.

Data Structures
struct	st_entry
struct	st_bin
struct	_search_table
Typedefs
typedef guint8	char_map_t [256]
	Maps one char to another.
typedef _search_table	search_table_t
typedef void(*	st_search_callback )(gpointer ctx, struct shared_file *sf)
	Needs brief description here.
Functions
size_t	match_map_string (char_map_t map, gchar *string)
	Apply a char map to a string, inplace.
void	st_initialize (search_table_t *, char_map_t)
	Initialize permanent data in search table.
void	st_create (search_table_t *table)
	Recreate variable parts of the search table.
void	st_destroy (search_table_t *)
	Destroy a search table.
void	st_insert_item (search_table_t *, const gchar *, struct shared_file *)
	Insert an item into the search_table one-char strings are silently ignored.
void	st_compact (search_table_t *)
	Minimize space consumption.
void	st_search (search_table_t *table, gchar *search, st_search_callback callback, gpointer ctx, gint max_res, struct query_hashvec *qhv)

---

Typedef Documentation

typedef guint8 char_map_t[256]

Maps one char to another.

typedef struct _search_table search_table_t

typedef void(* st_search_callback)(gpointer ctx, struct shared_file *sf)

Needs brief description here. Bug: FIXME: The type of this callback is too specific.

---

Function Documentation

size_t match_map_string (  char_map_t  map, gchar *  string )

Apply a char map to a string, inplace. Returns: length of string.

void st_compact (  search_table_t *   )

Minimize space consumption.

void st_create (  search_table_t *  table  )

Recreate variable parts of the search table.

void st_destroy (  search_table_t *   )

Destroy a search table.

void st_initialize (  search_table_t *  , char_map_t  )

Initialize permanent data in search table.

void st_insert_item (  search_table_t *  , const gchar *  , struct shared_file *  )

Insert an item into the search_table one-char strings are silently ignored.

void st_search (  search_table_t *  table, gchar *  search, st_search_callback  callback, gpointer  ctx, gint  max_res, struct query_hashvec *  qhv )

---